ORION.pdf

15.1 Day One – Standard Training Course

February 2009

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Website Site: General:

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Proprietary Rights Computer Services Consultants (UK) Limited, hereinafter referred to as the OWNER, retains all proprietary rights with respect to this program package, consisting of all handbooks, drills, programs recorded on CD and all related materials. This program package has been provided pursuant to an agreement containing restrictions on its use. This publication is also protected by copyright law. No part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means, electronic, mechanical, magnetic, manual or otherwise, or disclosed to third parties without the express written permission of the OWNER. This confidentiality of the proprietary information and trade secrets of the OWNER shall be construed in accordance with and enforced under the laws of the United Kingdom. ORION™ is a registered trademark of CSC (UK) Ltd. The CSC Logo is a trademark of CSC (UK) Ltd. All other trademarks acknowledged.

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1 1.1 1.2 1.3 1.4 1.5 1.6

2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10

3 3.1 3.2 3.3 3.4

4 4.1 4.2 4.3 4.4 4.5 4.6

5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8

6 6.1 6.2 6.3 6.4

7 7.1 7.2 7.3 7.4

8 8.1 8.2 8.3

9 9.1 9.2 9.3 9.4

Introduction Background Important Notes Regarding This Documentation Training Overview Overview of the User Interface (for information) Orion Modelling, Analysis & Design Flowchart Graphic Editor - General Principles

Building the Model Getting Started – Project Parameters & Settings Creating Axes Creating Columns Creating Shear Walls Creating Beams Creating Slabs Member Re-Labelling (for information) Using Tables to Edit Multiple Members Wall Loads and Additional Beam Loads Generating a 3D View of the Model and Creating Additional Storeys

Building Analysis Pre-Analysis Model Options Performing the Analysis Post-Analysis

Beam Reinforcement Design Exercise Aims Beam Design Settings and Parameters Designing all Beams using Batch Mode Graphical Review of Passing / Failing Members Interactive Beam Design Creating the Beam Elevation Drawings

Column & Wall Reinforcement Design Exercise Aims Column Design Settings and Parameters Designing all Columns using Batch Mode Creating a Column Schedule Creating a Column Output Report Creating a Foundation Loads Report Interactive Column Design Creating the Column Reinforcement Plan

Slab Design and Detailing Introduction Create Slab Reinforcement Strips Editing the Bar Layout Creating Slab Output

Creating a Flat Slab Model

1 1 2 2 3 4 5

9 9 15 21 32 35 41 48 49 51 56

61 61 65 67 71

83 83 83 83 86 87 95

96 96 96 96 97 99 100 101 112

116 116 117 120 121

124

Introduction Creating the Flat Slabs in the Model Creating Slab Loads and Openings Creating Additional Storeys

124 124 127 130

Building Analysis for Flat Slab

132

Pre-Analysis Performing the Analysis Post-Analysis

Gravity Load Chase Down using Finite Element Analysis Exercise Aims Finite Element Model Generation Options Generating/Performing the FE Analysis Model Cross checking the Finite Element Results

132 133 136

140 140 140 143 149

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Standard 10 10.1 10.2 10.3 10.4 10.5 10.6

Designing the Flat Slab Introduction Finite Element – Post Processing Settings Floor Analysis Post Processing Exporting and Displaying Contours Exporting to DXF (for information) Designing the Columns/Walls

Appendix A : Wind Load Specifying Wind Combinations Applying a Single Wind Load to Each Floor Applying Wind Loads directly to Columns & Walls

Appendix B: Beam Design Settings and Detailing Beam Design Settings

Appendix C: Column Design Settings and Detailing Creating the Column Detail Drawings

Appendix D : Foundation Design Introduction Pad Footing Design Strip Footing Design Raft Foundation Design

Appendix E : Load Combinations and the Loading Generator The Loading Generator

Appendix F : Report Manager Concrete and Form Estimation Reports Report Manager

Appendix G : Polyline Column Editor Creating an L-shaped column.

Appendix H : Slab Design using FE Analysis Introduction Creating FE Slab Strips Finite Element Model Generation Finite Element Model Generation Updating the FE Strips with Reinforcement

Appendix I: Enhancing the General Arrangement Drawings Creating Dimensions Shrinking Axes and Setting Unused Axes to Ghost Creating Slab Section Views

Appendix J : Orion Data File Structure and Project Settings Project Settings

152 152 152 153 162 163 164

166 166 167 171

174 174

182 190

194 194 195 199 203

208 208

214 214 215

216 216

220 220 220 221 222 226

228 228 232 233

236 237

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1 Introduction 1.1 Background Orion is developed for the analysis, design and drafting of Concrete Building Stuctures. Unlike general purpose structural analysis programs, Orion is concentrated on accurate analysis, fast data preparation, automated reinforced concrete design and automated preparation of engineering drawings and details. Building systems have the following common structural features: Geometry of a building system generally formed principly by horizontal beams and vertical columns. Most of the time, the column and beam elements have similar cross-sections so that standard section types can be formed. The in-plane stiffness of the floor slabs is considered to be high, forming rigid diaphragms at each floor level. Applied loads are either in vertical (dead and imposed loads) or horizontal (wind, soil pressure or earthquake) directions. There will often be repetition (in whole or in part) of floor layouts from one level to the next. General arrangement drawings (GA’s) are somewhat stylised, but given the constrained area of application outlined above, the system allows the model to be described by the development of GA drawings at each floor level. Even that process is further simplified since beams etc are dealt with as coherant objects, not just lines. The more simplistic centre line analysis model is automatically created in background at the same time. For example, in reality, 300 wide beams and 400 square columns along an external elevation may be arranged with the outside faces flush which would mean that their true centre lines are not aligned. It would be common practice to ignore this degree of mis-alignment for analysis purposes. Orion will not un-necessarily complicate the analysis model. In addition – different preferences can be held and automatically used for analysis and design purposes. For example, beam flanges can be ignored in the analysis but then utilised for reinforcement design (sagging moments only) without any re-modelling. In summary, an Orion model allows you to •

Create GA drawings

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Design the Floor Slabs, and de-compose floor loads onto beams.

•

Analyse the building frame

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Design continuous beams, columns. walls, and foundations (pad, strip and raft)

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Automatically generate RC detail drawings.

Note that analysis and design results are represented so that the reports look like a "Building Output" by classifying the members as columns, walls, slabs and beams with the same notations used in the floor plans.

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Standard 1.2 Important Notes Regarding This Documentation This document is primarily intended to accompany a formal training course. However, it has been decided that it will be distributed with the software as an alternative means of getting started. If you are using this document and have not attended a course you will still find it very informative but we ask that you note the following: •

Each part builds on the last so you need to work from start to finish.

•

In many places the notes will simply say “Set up the options/settings like this”. Within the notes there is little discussion of what effect alternative selections would have. This is the sort of additional information that would be covered during discussions in the training course or the informal question and answer sessions.

•

The introduction above gives an indication that you will need to develop an appreciation of the distinction between physical, analysis, and design models. Once again, this is the sort of additional information that would be covered during discussions in the training course or the informal question and answer sessions.

•

In particular, time should be put aside towards the end of the formal training to allow you to further discuss the above and also investigate how you can set up Orion so that it works as closely as possible in accordance with your standards/requirements.

•

Background

•

Important Notes Regarding This Documentation

1.3 Training Overview This training document will cover the main functions of Orion by using a simple 4 storey model. It is intended that after the course you should be capable of applying the techniques learnt to more complex geometries.

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Standard 1.4 Overview of the User Interface (for information) The various components of the user interface are shown below:

Structure Tree

Plan View

Members Toolbar

3D View

Layer Toolbar

Form Plan, Detail and Design Status tabs

Plan/3D View tabs

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Standard 1.5 Orion Modelling, Analysis & Design Flowchart The following flow chart demonstrates the typical procedure, for analysis and design within Orion. These options are fully described in the Orion Engineers Handbook.

1. Build the Model

Slab design based on tabulated code coefficients

2. Derive Beam Loads
Yield Lines or
FE decomposition for Beam Loads

3. Run Building Analysis Generates gravity and lateral design forces for column/walls and beams

If a Flat Slab? (or sub frame approach)

YES

3a For Flat Slab Construction Use FE Floor Analysis to create sub frames per floor, and chase gravity (only) loads down through the structure. These Gravity Loads replace those from the Building Analysis

NO

4.1 Beam Design

4.2 Column/Wall Design

4.3 Slab Design

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Standard 1.6 Graphic Editor - General Principles In a formal training course your tutor will demonstrate these methods to you. If you’re working through the notes independently you should just read this section and then return to it as necessary when you need to use the features/methods it describes.

1.6.1 Selecting single and / or multiple members Several entity selection options are available to select single and/or multiple elements for editing. Only visible objects can be selected using one of the selection methods. The entity selection options are located in the "Edit" drop down and toolbar. Available entity selection options are: Select Entity Option After clicking on the "Pick" icon from the Members Toolbar, a single element can be selected by simply picking a point on the entity. To select a second and further objects, you can press the CTRL key while picking entities successively. If a selected element is picked again, then it will be de-selected. Window Selections After clicking on the "Pick" icon from the Members Toolbar, multiple elements can be selected by enclosing them in a selection window. A selection window is a rectangular area that is defined in the drawing area by dragging two opposite corners. Two types of window selection are available. "Select Entity (Window)" option selects entities that are entirely within the selection area. "Select Entity (Crossing)" option select entities within and entities crossing the edges of the selection area. "Select Entity (Window)" is performed by clicking and dragging from left to right as shown below.

Window Selection: Selects Column 1S2 only. "Select Entity (Crossing)" is performed by clicking and dragging from right to left: By reversing the 1st and 2nd points in the diagram above, Axes "A" and "1", Column 1S2 and 1S3 would be selected

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Standard Fence Selection Fence is a line that selects all entities that it passes through. To perform "Select Entity (Fence)" hold down the SHIFT key and drag a line that crosses all elements that are intended for the selection set. This option is useful when a set of non-orthogonal entities are to be selected.

Fence Selection: Selects Axes "A" and "B".

1.6.2 Update - Editing a member For example, in order to edit an existing beam: 1.

Select an existing beam.

2.

Modify the fields such as "Label", "b" and "b2” in the "Beam Menu".

3.

Press the "Update" button in the toolbar or Modify menu.

You can repeat this process to as many members as you wish. One member at a time can be edited by this method. If you want to update several beams at once, you can use "Beam Table" in the "Member" menu.

1.6.3 Deletion – A single / multiple members For example, in order to delete an existing beam: 1.

Select an existing beam.

2.

Press the "Delete" button in the toolbar or Modify menu.

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Standard 1.6.4 Deletion – Selective deletion from a group of members For example, in order to delete all the slabs from within a selection window: 1.

Perform a window selection (as described earlier in this Appendix).

2.

Press the "Delete" button in the toolbar or Modify menu.

3.

From the "Element Filter" check "Slabs" only

4.

Click on OK

1.6.5 Object Snapping (Osnaps) The cursor can be made to snap onto the endpoint, midpoint of an individual line or intersection of two lines etc. to assist in creating axes or dimensioning or other positioning commands. Default Osnap Settings can be switched on in the “Edit” drop down and the toolbar.

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Standard 1.6.6 Basic View/Zoom functions The Graphical Editor provides several ways to control the display of the drawing in the drawing area. You can zoom to change the magnification or pan to reposition the view in the drawing area. All display control options are located in the "View" drop down and the toolbar. The following options are available: ReDraw The "Redraw" command re-displays all the drawing entities in the drawing area without re-generating the drawing objects. After a redraw, the drawing is completely updated. ReGen The "Regen" command re-generates all drawing entities using stored geometry information. This command is slightly time consuming than the redraw function. Zoom Window You can quickly zoom in on an area by picking the opposite corners of the zoom window defining it. After selecting the "Zoom Window" option, specify the opposite corners of the zoom window in the drawing area by dragging two points. Zoom Previous All zoom operations are stored. So, anytime, a previous display can be recalled using the "Zoom Previous" option. Zoom Extents "Zoom Extents" displays a view that includes all objects in the current storey at the highest magnification that will fit in the drawing area. Zoom Limits "Zoom Limits" displays a view that includes all objects contained within the active sheet borders at the highest magnification that will fit in the drawing area. Zoom (+) and Zoom (-) "Zoom (+)" increases the magnification of the current view by 10% and "Zoom (-)" decreases the magnification by a similar amount. This option can be used to quickly zoom in and out to the centre of the current view. Pan After selecting the "Pan" option, you can pan the drawing image to a new location by dragging two points that defines the pan direction and amount.

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2 Building the Model 2.1 Getting Started – Project Parameters & Settings 2.1.1 Exercise aims •

Launching Orion software

•

Entering Project Code

•

Entering Project Parameters (Type of Analysis, Material Properties etc)

•

Selecting Drawing Sheet

•

Entering Storey Height

•

Specifying some Program Design Settings

The object of this exercise is to familiarise you on how to start a new project in Orion and how to input some basic project parameters.

2.1.2 Launching Orion


Load Orion so a screen similar to the following appears.

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Standard 2.1.3 Creating a New Project






Click New Project, (leaving the box to Discard Current Project Settings unchecked). Enter a Project Code. Type the code as shown using the ‘_’ character to denote spaces.

Then Click OK

This will automatically create a folder called Training_Course_Model_1 beneath the default data folder shown on the previous page. This will be used for storing all the model data. Note: For more details about the Orion Data File Structure and Project Settings refer to the

Appendix of this manual.

2.1.4 Entering Project Parameters The following Project Parameters window now appears where the Design Codes can be selected. Currently the program supports design to either BS8110-1997 or CP65.




Ensure your required design code is selected and then click the General tab.

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Click the Select button to choose a coefficient of subgrade reaction for the use in Foundation Design.




Now click the Lateral Loading tab so the following screen appears.

Note: With selections as above, Fx and Fy lateral load cases will be automatically generated based on 1.5% of the dead load only.


Now click on the Lateral Drift tab so the following screen appears.

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Standard 2.1.5 Sway Considerations This is really a question of the building’s susceptibility to 2nd order effects. Refer to BS8110:Part 1 clauses 3.2.1.3 & 3.8.3. As with other codes (including the steel code), this provides methods for adding in second order effects. If braced then sway moments between beams and columns negligible and can be ignored. Deciding whether or not the building is braced/unbraced in each direction, is currently a matter of engineering judgement.

Braced or Unbraced in each direction?

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Proceed to the Title tab and fill in the job particulars.




Click OK to get back to the Open Project dialog and then OK once more to proceed.

2.1.6 Drawing Sheet Selection Orion has the unique ability to create working drawings from the design data. After having entered the project parameters the drawing sheet selection dialog box will automatically appear.


Click on the drop down arrow to see the various sheet sizes available, pick A0 then click OK.

Note: You can enter your own sheet size in the width and height box if your required size is not available. You can also change the drawing and detail scales from this dialog.

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Standard Note: The sheet origin (0,0) is located at the lower left corner of the drawing sheet. If after creating your model, you find it is too close to the edge of the sheet, you can reposition it by clicking on the Sheet Origin button.

2.1.7 Inserting Storey Height The next dialog prompts for the Storey height for the 1st storey


Enter the storey height as 3300mm as shown below then click OK.

After entering the 1st storey height, the main drawing area (Graphical Editor) appears.

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Standard 2.2 Creating Axes 2.2.1 Exercise Aims •

Understanding Axis Directions

•

Using the Orthogonal Axis Generator

•

Rotating & Stretching Axes

•

Selecting Multiple Axes

2.2.2 Establishing Axis Directions and Labels Now we will begin to create the axes.


Pick Orthogonal Axis Generator from the File menu.

Alternatively the same command can be accessed by right clicking on the Axes branch within the Structure Tree and picking from the pop up menu. Note the text that is displayed at the bottom of the screen. This is prompting you how to proceed.




Hold down the Ctrl key while picking a point in the lower left hand region of the drawing sheet.

After picking the reference point the Axis Generator screen should appear.


Fill in the boxes on the Axis Generator as below.

Note: You could now click on the screen to define the co-ordinates of the reference point, however to ensure it has a sensible (i.e. whole number) offset from the origin hold down the Ctrl key on your keyboard while picking a reference point.

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Standard Note: The Orthogonal Axis Generator will create Direction 1 axes horizontally and give them Dir 1 - +/45 degrees Alphabetical labels, 2 axes will be created vertically with numeric labels. It is Y axisDirection (90 degrees) Dir 2 maintaining of the X axis worthwhile a convention so that the same axis directions are applied in all models. We would suggest all axes within +/- 45 degrees of the horizontal be assigned direction 1 Dir 2 +/- 45 and all axes within +/- 45 degrees of the vertical be assigned direction 2.degrees of the Y axis Dir 1

X axis (0 degrees)

Plan View in Orion 2D Model




Click on OK, the axes should appear as follows.

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Standard 2.2.3 Osnap methods The cursor can be made to snap onto the endpoint, or midpoint of an individual line or intersection of two lines etc. This will assist in creating axes or dimensioning or other positioning commands. Default Osnap Settings can be switched on in the “Edit” drop down and the toolbar.


From the Edit menu choose Object Snap Settings and ensure the Intersection, EndPoint and MidPoint Osnaps are switched on. Then click on OK.

The Osnaps you have specified become active when using either the Axis or Dimension commands.

2.2.4 Pick methods The last axis to be drawn was Axis 6. This is thus the currently selected axis and is shown as a solid blue line. The Structure Tree View also indicates the selected axis. Provided that the Pick icon is active on the members toolbar it is possible to select a different axis by left clicking on it. To select several axes at the same time hold down the Ctrl key whilst picking the axes. The solid blue line indicates the last axis selected, the other axes that have been selected can be identified by the small squares or grips that appear at the ends of the axes. The selected axes are also indicated in the Structure Tree View. Clicking on the axis label in the tree view also selects an axis. Pressing Ctrl whilst clicking in the Tree View allows selection of multiple axes.

2.2.5 Editing Axes


Clear any previous axis selections by clicking on the Clear Selection Set icon




Then use either of the pick methods to select only Axis 5.




With this axis selected, right click to activate the context sensitive pop up menu as shown.

Note: The commands available on the pop up menu will vary depending on what is selected.

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The pop up menu allows the selected axis to be edited in a number of ways.


Choose Rotate Axis

Then follow the prompt at the bottom of the screen.




Change the Angle in the Axis Properties to 95 degrees




Pick the base of rotation by clicking on the intersection of axis A and 5. Provided you have set up Osnaps, the cursor should snap to the exact intersection.

The axis should then appear rotated as shown below.

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Standard Repeat this procedure to rotate axis F by 10 degrees about the intersection of axes F and 1.




Help??

If you can’t recall how to do the above:

Click the Pick icon Click on Axis F to select it. Right mouse click and choose Rotate Axis Type in the angle as 10 Click on the Osnap intersection of axis F and 1


The axes should then appear as follows:

2.2.6 Selecting/Stretching Multiple Axes Next we will stretch all the vertical axes so that they all extend above axis F.


From the Edit menu choose Select Entity (Fence) and then drag a line between Axis E & F through all the vertical axes so they are all selected.




Right mouse click to bring up the pop up menu and pick Stretch Axis




Click and Hold with your left mouse button near Axis 6 and drag up past Axis F.

The screen should now look as shown below.

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Standard 2.2.7 Creating Axes Individually In the training example it has been possible to create all the Axis Lines using the Orthogonal Axis Generator so it will not be necessary to create axes individually, however there will be many occasions in other models when you will need to add individual axes to an existing grid layout. There are two ways to achieve this: Either, i)

Create a new line parallel to an existing axis. To do this, select an existing grid line then right click to activate the context sensitive pop up menu. Choose Offset Axis. Define the offset and the label for the new axis and then left mouse click to one side of the initially selected axis to indicate the side where the new axis is to be drawn.

ii)

Create a new line by using the Axis Tool. To do this, select the Axis Tool from the Members Toolbar. Define the new label, then left click and drag to draw the axis. Note that using this method the line is being drawn ‘free-hand’ making it difficult to draw the line to an exact angle or length. To rectify this, hold down the CTRL key when drawing the line. This forces the angle and length to snap to multiples of the values shown in the Graphic Editor View Settings – Plan Tab.

With an Angle Step of 15 deg and a Length Step of 1000, holding down CTRL will force the axis to snap to an angle of 0,15, or 30 degrees etc. and a length which will be a multiple of 1000mm.

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Standard 2.3 Creating Columns 2.3.1 Exercise Aims •

Take a look at the different modelling Options

•

Creating Rectangular & Trapezoidal Columns

•

Inserting Multiple Columns

•

Creating Circular Column

2.3.2 The Properties and Options with Columns Having created the grids we will now create the columns. However there are quite a few settings and options with columns so we will have a brief look at these before proceeding.




Click the Column icon or go to Main Menu and pick Member/Column.

The Column Properties dialog should appear as shown. There are 4 tabs to this dialog.

Insertion Options to update the e1 and e2

Dir 1/2 button - Indicates the column faces are parallel to which directions (axis). This will be demonstrated within the next few pages. (Pay attention to the column at grid B / 5)

- Column end conditions options (Fixed / Hinged). Simply click on the button to toggle the end conditions. Note pinned joints in concrete structures should be used with caution.

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Standard Note: To view the calculated section properties of a column, click on the Model tab within the Column Properties dialog and then click on the Display Section Properties icon. The calculated properties can be edited manually by overwriting the zero values shown in the dialog boxes.

Orion will allow the user to model and analyse column or wall drop panels. These can then be taken into account for the Punching Shear Checks. b1 = width of drop b2 = length of drop e1 and e2 = allow the drop to be offset h-Head = depth of the drop from the top of the slab ie. If the slab is 300mm and a h-Head of 600mm is specified then the drop would project 300mm below the underside of the slab.

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Support Types > [Default]. The Default support condition is defined in Member > Support Types. The user can define additional support conditions for translation / rotation in the x, y and z axis. (mm) del z (bot) – The user can define different base levels for each column relative to the datum, i.e. for a sloping site.

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Standard 2.3.3 Creating Rectangular Columns We will start by creating some rectangular columns.

The 1st column we will create will be of size 300x600 where 600 will be in direction 1. Also these columns are to be parallel to the grids in both directions 1 and 2.


Click the Dir 1/2 faces are parallel to

button to indicate the column both directions 1 and 2.




In the dimensions box enter 600 in b1 and 300 in b2

Note: by right clicking on these boxes we can select a dimension from those available instead of typing a value.


Click the centrally placed column icon from the Insertion Options to update the e1 and e2 values as shown to the right.

The Column Properties should now be as shown below.

Label Corner - Allows the user to define the label position relative to its four corners.

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Note: All columns must be entered at grid intersections.




Place the cursor over Grid 1 and Grid B intersection and left click to insert the column.




Click on the Zoom Window icon Window




Then box around the Grids A-B/1-3 to see the inserted column.

or from the Main Menu bar pick View/Zoom

Note: the circular symbol labelled with an “R” indicates the centre of rigidity of the floor plan. As there is currently only one column on this floor the centre of rigidity is at the centre of the column.




Click the Zoom Limits icon

to see the limits of the drawing sheet.




Now enter another column of the same size at Grids B/2 by positioning the cursor at this grid intersection and left click the mouse.

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Standard 2.3.4 Inserting Multiple Columns Multiple columns of the same size can be entered by clicking and keeping the left mouse button held down, and then drag along the grid intersections where similar sized columns are to be placed.


Do this along the Grids B/4 –5, so your screen should look as shown.

Note: The column at Grid B/5 is drawn as a parallelogram and is placed parallel to both the grids it is inserted at because the Dir: [1/2] button was selected. If only Dir: [1] button was selected then the column would be drawn as a rectangle, only parallel to the grid in direction. The reverse applies if the Dir: [2] button is selected.


Now enter the rest of the centrally placed 600x300 columns at the following Grid Intersections: D/1, D/4, D/5, E/4 & F/5.

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Standard So your screen should look as follows.

Centrally Placed 600x300 Sized Columns

Note: If you place a column in the wrong location, simply right mouse click to display the pop up menu and choose Delete.


Now with the properties for the 300x600 column active, use the Insertion Options to align the column so that its top left corner is positioned flush with the grids. With the alignment as shown, the eccentricities should change to e1=0 and e2=300.




Then enter the column at Grid F/1




Click on the Zoom Extents icon should look as below.

so your screen

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Members can be ‘nudged’ into their final position using the keyboard cursor keys.


Using the cursor keys ‘nudge’ column 1C10 to an eccentricity of e1 = 150mm, e2 = 175mm. (Alternatively type these eccentricities into the Column Properties dialog and click Update.)

Note: The size of step can be controlled via Graphical Editor by adjusting the Member Section Eccentricity Step on the Plan tab.

View

Settings,




Use the Insertion Options again to align the next column thus so that its right edge is flush with the grid line. Ensure that Dir: [1/2] is selected and enter this column at Grids E/5.




Zoom in to this column and as shown below it should be labelled as 1C11.

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Now enter some square columns of size 350x350 centrally placed at grids and parallel to axis in direction 1 only. These columns are to be placed at Grids E/1, E/2 & F/3 as shown below.

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Standard 2.3.5 Creating Circular Columns Now we will enter a circular column 400mm in diameter.


Type 400 in the b1 box and leave b2, e1 & e2 as 0, then

Note: to enter a void in the centre of the column, enter a negative value in the b2 box (i.e. 100mm pipe would be entered as -100).

click on Grid F/4 to enter the circular column.

View of Circular Column 1C15

2.3.6 Using the Polyline Column Editor This option allows the user to specify any shape column for the analysis and design. Please refer to the appendix for information on how to use the ‘Polyline Column Editor’.

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All the columns have now been entered. They should be shown positioned at the grid line intersections below:

1st Storey Column Layout Hint??

Have you missed out any of the columns?

Take a look at the Structure Tree - If your model is correct it should be indicating 15 columns at this stage.

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Standard 2.4 Creating Shear Walls 2.4.1 Exercise Aims •

Creating C-Shaped Core Wall

2.4.2 Overview of Options You will see many of the options are similar to the options in the columns dialog but there are a few that refer to walls only. General dimensions.

The geometry of the wall is defined. The wall is defined between grid points. Extension zones (Ext) can also be defined to model the physical position of the wall. Note – It is recommended that the extension zones are kept to a minimum as shown below. The orientation of the wall is defined by the label direction. This is controlled automatically by Orion. In simple terms Ext I refers to the start of the wall, and Ext J to the end.

Ext I

Ext J

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Standard Material Properties – The choice of material can be controlled on a wall by wall basis. However it is recommended to use the [Default] material properties controlled by the Parameter Settings. It is recommended that changing any material properties in this window should be done with caution.

(mm) del z (I,bot) – The base levels of ends I can be controlled based off the datum. (mm) del z (J,bot) – The base levels of ends J can be controlled based off the datum. This enables sloping base of walls. Support Type – The support Types can be defined as per the columns. It is recommended to use [Default] settings. The analytical model for this shear wall can be controlled on an individual basis. The Mid-Pier and FE Shell Methods are described fully in the Engineers Handbook. It is recommended to leave this setting as Default.

Mid Pier Model

FE Shell Model

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Standard 2.4.3 Creating a Core Wall Now we will create a lift core wall which will be 200mm thick and C-shaped.


Pick the Shear Wall icon or go to Member/Shear Wall from the Menu bar.




Enter 200 in the b: dimension box, 100 in the b2 box and enter 100 in the Ext: I & J boxes. (This is how far the wall extends past the grids that it is inserted).




Click on the Insertion Options icon and select the wall to be centrally placed on the grid




Insert the wall by clicking and dragging from the start grid C/2 to C/3.




Do the same at Grid D/2 to D/3 and Grid C/2 to D/2 as shown below.

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Standard 2.5 Creating Beams 2.5.1 Exercise Aims •

Creating Multiple Rectangular Beams

•

Applying Brickwall Loading

•

Adding Supports for Secondary Beams

2.5.2 Creating Multiple Rectangular Beams


Pick the Beams icon or go to

Member/Beam.

We will 1st enter some Beams along Grid B/1-6 of size 300x600.


In the Beam Status Bar ensure that dimension b is 300 and the dimension h-bot is 600.

Label – The labels will automatically generated in the model, ie. 1B1, 1B2, 1B3 etc…. b - The width of the beam b2 – This option determines if the beam is offset in relation to the grid it is being created. This can be manually applied or by using the [Default] offsets. Pinned – Left clicking on the blue beam allows the user to define pinned end supports, on either / both ends of the beam h-bot – This is the amount you wish for the beam to project below the slab. H-top – This is the amount you wish for the beam to project above the slab. See diagram below.

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I / Shear Area / hf / bf and E – These will all be calculated automatically based on the Material Properties / Beam Size and the connecting slabs for the calculation of the flanges.

The beam along Grid B/1-6 is to be placed in the centre of Grid B so that the b2 dimension is half of the b dimension,


Ensure this by clicking on the icon 150mm as shown above left.

this will automatically set the b2 dimension to




The beam is positioned at Grid B/1-6 by left clicking and dragging from the start of Grid B/1 and releasing when your cursor is at Grid B/6 so that 4 beams are entered as shown below.

Note: Like the columns the beams are automatically labelled based on the storey and numbered sequentially as they are entered. Orion has automatically split the beam into four individual members between the columns.




Now enter some more beams in the following order of same size at the following locations:

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From

To

Beam Size

D/1

D/6

300 x 600

E/1

E/5

300 x 600

2/A

2/C

300 x 600

4/A

4/F

300 x 600

1/A

1/F

300 x 600

5/A

5/F

300 x 600

6/B

6/D

300 x 600

so your screen should look as shown on the next page.

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Standard

Note: A beam will not be placed where a wall already exists. A beam was not placed at Grid D/2-3 because of this.


The perimeter beams along the top and bottom edges are only 250mm wide and 800 deep. Enter them as indicated in the table below ensuring they are placed centrally on the grid:

From

To

Beam Size

F/1

F/5

250 x 800

A/1

A/5

250 x 800

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Standard


A *** Slender Section*** warning message should appear, click on OK to accept and your screen should look as follows.

Note: The perimeter beam at Grid A/1-5 has been created as a single beam spanning > 17m and supporting the vertical beams along grids 2 and 4. It is possible to redefine this part of the model so that the beams along grids 2 and 4 become cantilevers that support the perimeter beam.




Delete the perimeter beam along the bottom edge and then re-enter it as 3 separate beams as indicated in the table below:

From

To

Beam Size

A/1

A/2

250 x 800

A/2

A/4

250 x 800

A/4

A/5

250 x 800

so your screen should now look as follows.

Page 39

Standard 2.5.3 Inserting the rest of the 1st Storey Beams


Define the rest of the 1st storey beams centrally on the grid (with the b2 dimension half of the b dimension) as follows:

From

To

Beam Size

2/D

2/E

300 x 600

3/E

3/F

300 x 600

C/3

C/5

250 x 600

3/C

3/D

200 x 500

Now your screen should look as shown below:

Hint: Have you missed out any of the beams? 

Take a look at the Structure Tree It should indicate 37 beams.

1st Storey Beam Layout

Page 40

Standard 2.6 Creating Slabs 2.6.1 Exercise Aims •

Creating 1 & 2 way spanning Slabs

•

Creating Cantilever Slabs

•

Creating Slab Openings

2.6.2 Creating 1 & 2 Way Spanning Slabs For Beam and Column construction slabs can be designed based off co-efficients methods in the code. Other methods of design are considered later.

Note – Current loading method assumed to be the Yield Line Method




Select the Slab icon or from Member/Slab.

We will now enter the slabs at the 1st storey.


In the Slab Properties enter the slab thickness h to be 120 and the cover to be 25, all dimensions are in mm.


Then click on the Loads tab and enter an Additional Dead Load of 1.2kN/m2 and in the Imp. Load box do a right mouse click and select a value of 1.5kN/m2.

Note: The self weight is calculated automatically depending on the slab thickness. Returning to the General tab, click on the Type box and all the possible Slab Types will appear in pop up menu as shown below. The slab type relates to table 3.14 in the code and is used to obtain correct reinforcement values, based on the coefficient method. For ease in creating this model we will initially leave the Slab Types as 1. Once all the slabs have been created the program can be made to automatically calculate the correct type for each slab.

Enter the 1st slab by positioning the cursor between Grid A-B/1-2, then left click the mouse.




Your 1st slab 1S1 should appear as below including the yield line for the slab load distribution.

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Standard




Repeat this process to define two more 120 thk slabs as follows:

Region

Thickness (mm)

Dead Load (kN/m)

Live Load (kN/m)

A/2 – B/4

120

1.2

1.5

A/4 – B/5

120

1.2

1.5

So now your screen should look as follows.




Now enter some 150 thk slabs which have the same Additional Dead Load as the existing ones but are to have an Imp. Load of 3kN/m2

Region

Thickness (mm)

Dead Load (kN/m)

Live Load (kN/m)

C/3 – D/4

150

1.2

3.0

C/4 – D/5

150

1.2

3.0

Page 42

Standard D/4 – E/5

150

1.2

3.0

E/3 – F/4

150

1.2

3.0

E/4 –F/5

150

1.2

3.0

B/5 – D/6

150

1.2

3.0

So now your screen should look as follows.




Now enter some 200 thk slabs at the following locations:

Region

Thickness (mm)

Dead Load (kN/m)

Live Load (kN/m)

B/1 – D/2

200

1.2

3.0

B/2 – C/4

200

1.2

3.0

B/4 – C/5

200

1.2

3.0

Page 43

Standard D/1 – E/2

200

1.2

3.0

D/2 –E/4

200

1.2

3.0

E/1 – F/3

200

1.2

3.0

So now your screen should look as follows.

2.6.3 Setting Slab Types Automatically To automatically set the slab types in accordance with table 3.14 proceed as follows:


Clear any members that are currently selected by clicking on the Clear Selection Set icon

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Right mouse click on the Slabs folder in the Structure Tree and select Set Slab Types Automatically as shown below

The Slab Type Determination dialog appears as shown below.

Note – For continuity of the slab type to be considered, the adjoining slab edge must be 70% or greater in length.




Click on OK to proceed




Click on OK once more.

Page 45

Standard 2.6.4 Creating Cantilever Slabs Now we will enter a Cantilever slab


Select the Slab Type 12 and enter a thickness h of 150mm.




Enter the length of the cantilever slab to be 1000 in the L-cant box. So your status bar should look as shown to the right.




If you click on the Display Slab Label icon so a cross goes through it. The effect of this is to switch off the label for the slab on the drawing.




Before placing the slab click on the Loads tab. Ensure the Load values are as follows: Dead Load 1.2 kN/m, Imp. Load 3kN/m2

Note - Each cantilever slab can only be defined relative to one beam. Therefore to place a cantilever slab along the side of a building, you would be required to specify separate slabs for each of the beams along the edge. Also the insertion points for the beginning and end points of the slab should coincide with those of the beam to which it is adjacent.

Tip: Click along the RHS of the beam. When clicking from intersection to intersection click in an anticlockwise direction.




With the cantilever slab properties still active, type the slab width in the b-slab box as 3000




Ensure that the cantilever length, L-cant, is still 1000




In the d box, type the distance from the grid where the slab is to be inserted as 4000. The slab thickness, h is 150 and the loading is the same as the other cantilever slabs.

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Now click and drag from Grid 3/F to 1/F so the cantilever slab 1S16 is shown as below.

So you can see from this that b-slab controls the width of the cantilever and d controls how far from the grid line the cantilever slab is positioned. This then allows you to control the size of the cantilever slabs easily.

Hint??

Have you missed out any of the slabs?

Take a look at the Structure Tree - it should be indicating 16 slabs.

2.6.5 Additional information about slabs (for information)

Rel.Level – This allows a step in the slab, however if the relative difference in elevations will cause a separation in diaphragms, then try using plane definitions.

Page 47

Standard 2.7 Member Re-Labelling (for information) 2.7.1 Exercise Aims •

Re-label all the columns, beams and slabs in a more ordered sequence.

2.7.2 Changing the member labels Currently the members have been labelled in the order in which they were created. It would be preferable to have them labelled to reflect their location on the plan.


From the Edit menu select Re-label Members.




Choose the options as shown below and then click on OK.

Page 48

Standard 2.8 Using Tables to Edit Multiple Members 2.8.1 Exercise Aims •

Changing properties of all selected members in one go by using the member tables

2.8.2 Changing Properties of all Selected Members To demonstrate this function we shall change the slab thickness of all the slabs in the model.


Clear any previous selections by clicking on the Clear Selection Set icon




Select all the slabs by placing a window around the model extents using the Pick icon.




Right click and choose Member Tables > Slab Table

The Slabs Table should now appear as shown, containing all of the selected slabs. From here it is possible to change either the property of an individual member in the table or update a property of all the members at the same time.




Highlight the column, h as shown by clicking on it.

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Without clicking anywhere else, type the new required slab thickness, 200mm as shown.




Press Enter and the new thickness have been auto-applied to all the slabs in the table.




Note: When the slab thickness is changed the self weight is also automatically modified.

2.8.3 Changing Properties of One Member in the table only


Change the thickness of slab 1S16 to 180mm as shown below




Click on one of the other rows in the table to move the focus off 1S16 as shown




Click on Close

Note: If several members of different types are selected, you will not be able to right click and choose Properties. Instead you should right click and choose the required Member Table. Alternatively you can have the Member Tables toolbar docked permanently on screen - This can be done by right clicking on any icon at the top of the screen to display the menu of available toolbars. If the Member Tables toolbar is not checked then click on it. The toolbar will be displayed and can be dragged to a suitable position.

Page 50

Standard 2.9 Wall Loads and Additional Beam Loads 2.9.1 Exercise Aims •

Apply Beam Wall Loads

•

Apply Additional Beam Loads

Note: Beams will be loaded based off the Default Slab Load method. For this example currently Yield Line.

2.9.2 Apply Beam Wall Loads


Select the beam at the right end of grid F and right click to display the right mouse click menu.




Choose Edit Beam Wall Load from the menu.




To define the load click Select and choose BRICK WALL (200 mm), then fill in the Wall Height as 3.4m as shown below.




Click on OK and the beam is shown hatched, indicating it has a brick wall load applied. (If you don’t see any hatching check that you have the Graphical Editor View Settings defined correctly).

Page 51

Standard To apply the same wall load to the other perimeter beams proceed as follows:


Right mouse click on the same beam again and this time choose Copy Beam Wall Load.




Using the Pick icon, select the remaining perimeter beams, remembering to keep the CTRL key held while selecting, so that each one is added to the existing selection set.

Hint??

If you have difficulty selecting the beams try this:

From the Layer Tool Bar at the left edge of the screen click on the Axis Layer Group icon. This will temporarily switch off the display of the grid lines. Now use the Pick icon to select the beams When all the beams are selected remember to switch the grid lines back on by clicking on the Axis Layer Group icon once more.




When the entire perimeter beams are selected, right click again and this time, choose Paste Copied Beam Loads from the menu.

Note: If warned that the wall load will be

replaced in the selected beams, as shown, choose Yes. The beams to which beam loads have been applied are clearly indicated for visual checking.

Page 52

Standard 2.9.3 Apply Additional Beam Loads


Select beam 1B30 as shown. (If the indicated beam is not labelled 1B30 try re-labelling the members once more as described in Chapter 2.7.)




Right mouse click to display the Pop Up menu and choose Edit Member Loads.

The existing loads on the beam are displayed. T2 and T1 are the slab loads from left and right. The self weight of the beam is also displayed.

Note: this is the chosen Load decomposition method for this beam [Default].


Click New Load

Page 53

Standard The three icons at the top of the Load Profile Editor allow you to add Uniformly Distributed Load, Partial Distributed Load and Point Loads respectively.




Click on the Partial Distributed Load icon and then click on the Load Generator button.




Click on the partial uniform load icon as shown.

Enter the distance, x to the start of the load as 1m


Enter the run of load, a as 2m




Enter the load intensity, P as G = 4kN/m and Q = 3kN/m




Click on OK

The load should be drawn as follows




If desired, type a label for the load then click on OK

This additional manually entered load is shown on the T0 diagram as below

Note: Solid Blue Lines denote the Dead Loads (G) Dotted Grey Line Lines denote the Imposed Loads (Q)




Click on OK

Page 54

Standard To display the ‘Total Added Beam Loads’ go to the ‘View Options’




Left click to tick the box Print Total Added Loads.




Click on OK

This will then display the loads added to each of the beams in the model after the Analysis has been performed.

Page 55

Standard 2.10 Generating a 3D View of the Model and Creating Additional Storeys 2.10.1

Exercise Aims •

Generate a 3D View of the Model

•

Inserting Additional Floors

•

Copying Storey Data from one floor to another

•

Editing the Storey Height

The building currently consists of only one floor. To complete the analysis model we shall generate additional floors. To assist in this process a 3D view of the model can be created. A 3D view of the model can be obtained which will allow you to choose different layouts of Plan view (P) and 3D view (3) windows. It is possible to create different 3D views in different windows.


From the Window menu select the Tile Vertical

Note: Alternatively, the Plan/3D View tab at the bottom of the screen can be used to cascade & tile the different windows

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Standard


Left click on the 3D View window to make it active, and then right click to display the 3D View menu.

The 3D View can be manipulated in a number of ways:

The Wireframe/Shaded/Stick View icons produce different rendering of the 3D view. Reducing the level of rendering increases the speed of dynamic panning/zooming.

Filters enable different member types to be filtered at each storey. 3D View Options enables viewing from different directions and elevations. Animation rotates the building about a vertical axis. Click & drag right mouse allows spinning, click and hold on mouse roller allows Panning, and moving mouse roller allows zoom in/out.

2.10.2

Inserting Additional Floors

Now we will generate an additional 3 floors, so the model will become a 4 storey building. To construct a 4 storey model we need to insert firstly a floor at the 4th floor.


Right click on the Storeys in the Structure Tree to display the Storey Menu




Choose Insert storey, or from the Main Menu select Building/Insert Storey.

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Standard


In this box type 4 then select OK

The screen should now look as follows.

The 4th storey has now been inserted but as can be seen it does not contain any members in the plan view.

2.10.3


Copying Floor Data to Other Floors

Right click on Storeys in the Structure Tree to display the Storey Menu and select the option Generate storey (or from the Menu bar Building/Generate Storey) so the Storey Generate dialog box appears.


Highlight St01 as the Source Storey and then St04 as the Target Storey.




Then click on OK.




After generating select Close.

From the Structure Tree you will see that St04 has a circle mark next to it but St02 & St03 don’t have this mark. Floors without any mark automatically adopt the same member layout as the floor above. Hence storeys St02 & St03 are assumed to be identical to the 4th storey. Whatever changes are made to the 4th storey will be carried through to the 3rd & 2nd storey. To make the 3rd storey different from the 4th storey, it would be necessary to first generate the similar member types from the 4th storey to the 3rd storey then modify the 3rd storey accordingly. Because the 3rd storey would now have a mark next to it in the storey list the 2nd storey would be similar to the 3rd storey. So we can do this as follows:


Right click on Storeys in the Structure Tree to display the Storey Menu and select the option Generate storey.

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Ensure that the source storey is St04 and the Target Storey St03 then choose OK




Then after generating choose Close.

From the Structure Tree you will see that St03 now has a circle mark next to it indicating that it is a unique and editable floor, as are St01 and St04. St02 cannot be edited, as it is identical to St03.

2.10.4

Moving between Storeys

The current storey displayed in the plan view will be shown in bold on the Storey menu in the Structure Tree. To change to a different storey, simply double click on it in the Structure Tree.


2.10.5

If you are not currently viewing storey 4, double click on Storey: St04 so that it is shown in bold (as shown on the right)

Editing the Roof




Select the Slab icon or from the Pull Down menu select Member/Slab.




Then select the Slab Type to be 1 and ensure the thickness is 200mm and the cover 25mm.




Then enter the slab where the lift wall is at Grid 2-3/C-D

So your screen should look as follows.

Page 59

Standard 2.10.6

Editing the Storey Height

We will now edit the storey height as currently each floor is 3300mm high based on the 1st storey generated earlier.


Select Edit Storey from the storey menu or by selecting from the Main Menu Building/Edit Storey so the Edit Storey dialog box appears as shown below.




To change a floor height: click in the cell for h(mm) at the desired storey, St01




Change the current value of 3300 to be 4000. Click outside the cell and you should notice the values in the Level column have changed as shown below.

1st Storey Bottom Level - The Number of Basements is only used for determining a factor used in earthquake analysis. (Not available in this version of Orion). Foundation Level –This is the length of the column below the datum level (St00), by Default 1100m

2.10.7

Specifying Imposed Load Reductions for Each Floor

The Edit Storey dialog is used for this purpose.


Click on the button to apply the Imposed Load Reductions.




Then select OK.

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Standard

3 Building Analysis 3.1 Pre-Analysis 3.1.1 Exercise Aims •

Model Validity Checking

•

Distribute Slab Loads & Beam Loads to all Beams

•

Run Building Analysis - Pre-Processor

•

Run Building Analysis - Post-Processor

•

Viewing the Analysis Output Report

3.1.2 Pre-Analysis - Model Validity Checking


From the Run menu choose Building Analysis.

This should then display the Analysis Form.




Click Load Combination Select and chose LC10, this will include the gravity load combinations (including pattern loads) and the NHF’s.

See the Appendices for further information regarding Load Combination settings within Orion.

Page 61

Standard The Parameters button allows the user to review/modify the Building Parameters specified previously. The Load Combination ‘Select’ and ‘Edit’ buttons can be used to view and if required modify the load combinations specified previously. The Storey Loads Editor can be used to view and if required modify the lateral load cases applied at each storey. The notional lateral loads are calculated automatically once the Building Analysis is complete. The Material section can be used to view the concrete and steel grades selected for each member group. The ‘Edit’ button can be used to change these settings.


Now click the Edit button so the following screen appears.




Click on the concrete grade button adjacent to Columns and then choose Concrete Grade C40 and check the Apply to All Members Types box as shown below and then click OK

This will set all structural members to have Grade 40 Concrete. Alternatively we could have set the Grade to be C32/40 for the Cylinder/Cube strengths.

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Standard

Note: Different Member Types are can have different concrete grades set globally in the Material Properties. However the grade can be varied from one member to the next within a Member Type.


Click on the steel grades button adjacent to Columns and then choose Grade 500 (Type 2) and check the Apply to All Members Types box as shown below and then click OK

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Standard


Check that you have the unit weight of concrete set to 24kN/m3 before proceeding.




Click the Bars button adjacent to Columns.

You will notice some bars have been selected by default. Bars can be unselected by clicking on them to remove the tick (similarly click to select).


Make sure the selected bars for today’s exercise are: H10 / H12 / H16 / H20 / H25 / H32

Note: You may prefer to modify the bars to select from. Some bars are only available in Europe and others in Asia. However, these training notes are based on the above bar sizes - if you make changes the member designs may differ from the manual. Also if you elect not to use certain bar diameters for column design, you should ensure that these bars are not referred to in the Column Design Settings later in the program. Similarly, bars not used for beam design should not be referred to in the Beam Design Settings.




Click OK to go back to the materials tab, then review (and modify if desired) the bar diameters to be used for beams, slabs etc.

Page 64

Standard 3.2 Model Options


Click on the Model Options tab

The model options shown here are fully described in the Engineer’s Handbook, found from the Help Menu. Automated generation of Rigid Zones (where beams frame in to columns/walls) is an advanced feature within Orion. Setting Rigid Zones to Maximum, or Reduced by 25% creates a more realistic model of the beam/column interface which reduces the design moments within the beams.

None – Centreline moments used for design. No Rigid Arms.

Reduced –Mom generated 25% from the perimeter of the section Diagram Shown with MAXIMUM Rigid Arms

Maximum – Moments at the face are used for the design. Rigid arms extend to the section perimeters (100%).

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Standard


Click on the Stiffnesses tab.

On this page the engineer can globally adjust the properties to be used for each member type. Note: The torsional stiffness factor has been set to 0.01 for the beams to prevent significant torsions from developing.


No changes will be made, click on Settings tab.

Total Hor. Drift Limit – This check is for the maximum total allowable displacement, which is checked at every storey level. 12000mm * 0.0014 = 16.8mm Relative Hor. Drift Limit – This check is in accordance with BS 8110: Part 2 and is the maximum relative displacement between each storey. 4000mm * 0.002 = 8mm These checks are performed for the NHF’s, Fx and Fy Note: For flat slab models there is an option to use undecomposed slab loads for the notional horizontal load calculation. See later notes. Page 66

Standard 3.3 Performing the Analysis




Click on Building Model Validity Check.

This will check that the building is valid for those conditions indicated.


Choose All Storeys and then click on the Check button.

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Standard

Note: Even if this reports no errors, it doesn’t guarantee that the building is modelled correctly. There can be other problems in the model that are not picked up by the validity checking process.


Assuming that no errors are reported, close the dialog

During the Building Analysis, the Beam Load Calculations (All Storeys) are completed (based upon your loading method – currently Yield Line). The slab loads are distributed onto the supporting beams; all the load data is assessed; the weights and mass centres of each storey are calculated and any notional lateral loads are determined. After analysis it is then possible to automatically perform Column/Wall Reinforcement Design and Beam Reinforcement Design for all members in the building.


Uncheck Column/Wall Reinforcement Design and Beam Reinforcement Design before clicking on Start to begin the batch analysis process.

The Beam Load Calculations commence and a warning message should be displayed.




Click Yes and the analysis process continues and then OK when the Analysis has completed.

Page 68

Standard Hint: By clicking ‘Yes’, in the above process to mark the cantilever beams, a small red triangle is attached to each one detected. The user can override this automatic marking back in the graphic editor by selecting the beam, right clicking and choosing Mark Free End of Cantilever Beam as shown. This may be necessary where two cantilever beams meet. (EG beams B3 and B36). The marking does not affect the analysis, however it does affect the way the beams are subsequently detailed.

3.3.1 Checking the notional lateral loads Once the Building Analysis has been performed, the weights of each storey can be viewed and if lateral loads were specified in the Project Parameters they can be viewed and edited.


Return to Pre-Analysis and select Storey Loads Editor.

By clicking on each of the storey labels in the upper table, the Fx and Fy values for each storey can be viewed and edited if required, in the lower table.


Click on Cancel to leave the notional forces unchanged.

Page 69

Standard

Point of Application Notional Horizontal Forces

Fx

CofG = Centre of Gravity

CofG

Fy Floor Plan 15.333m

Sheet Origin (0,0)

13.070m

Page 70

Standard 3.4 Post-Analysis 3.4.1 Cross Checking the Analysis Result An important cross check on validity of the analysis is the Axial Load Comparison Report. This report sums all the dead and live loads applied at each storey level and then also displays the axial forces in the columns and shear walls. These values should equate to each other (within a few percent), if they do not the reason for the discrepancy should be investigated.


Go back to the Analysis tab




Select Axial Load Comparison Report

The total “SUM OF APPLIED LOADS (Using Un-Decomposed Slab Loads)” values should be similar to those from the Decomposed Slab Loads table. Provided that any difference between the un-decomposed and the decomposed values can be accounted for, the Total Decomposed Applied Dead Load should be compared with the Total Delta G value from the “BUILDING ANALYSIS COLUMN/SHEARWALL AXIAL LOADS” table. Similarly, the Total Decomposed Live Load should then be compared with the Total Delta Q value. Any significant differences in these values also have to be able to be accounted for. If required the report can be printed, or it can be saved for later inclusion in a batch print out of all reports created by the program.


Click on Save Report

See following page for an example of the Axial Load Comparison report Summary – For Beam and Column Construction CHECK 1 Sum of Undecomposed Slab Loads

~

Sum of Decomposed Slab Loads

~

Total Delta G

~

Total Delta Q

CHECK 2 Total Decomposed Applied Dead Load CHECK 3 Total Decomposed Applied Live Load

Page 71

Standard Axial Load Comparison Report

Page 72

Standard 3.4.2 Model and Analysis Results Display The Analysis results can be viewed graphically from here. Various effects can be displayed and the results can be filtered by axis and by storey.


Click Model and Analysis Results Display

If too many labels are displayed the screen can appear cluttered as shown above. However, using the various drop-down filter buttons and the view settings, you can create something more meaningful.


Click the various filter buttons to create different views. The menu’s can be dropped down to choose what you want to show, and then the button can be toggled on and off.

This is the nodal points filter

This is the frame elements filter

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Standard

By clicking on the Filters button, located just to the left of the nodal points filter button, you can filter by storeys, axes and member type, as shown above. You can also do a Search for specific nodes, frame elements or shell elements by clicking on the binoculars icon, to the left of the filters button, as shown below.

A large arrow will point at the item you have searched for. Note – This is useful if the Building Analysis reports conditions on some nodes.

Page 74

Standard There are further filtering and setting options found in the View Settings window, which can be accessed from the View menu:

Below is a view of the model showing the displacement, using the Displacements filter. The X values have also been displayed, and the displacement scale has been increased.

Page 75

Standard This next view shows the frame loads and values for storey 4 only

Page 76

Standard 3.4.3 Analysis Output Reports (for information) The next stage is to prepare a report of the analysis results.


Select Analysis Output Report Preparation so the following dialog box appears.




Expand Storey 1 and highlight Columns and Walls (by holding down the CTRL key) as shown.




Click on the button to transfer all the columns and walls to the right hand side.




Click Next and on the next screen select Structural Members

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Standard




Select the results to display as shown. Note that ‘i’ results are at the top of the members and ‘j’ results are at the bottom.




Change the output options to match those shown below.

Note: Y – This denotes a Loadcase K – This denotes a Load Combination

Page 78

Standard

Sign Convention Positive Definition of Member Forces

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Standard




Click the Create Report button and a report should appear in WordPad as shown below.

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Standard


Close the Report and then choose Exit which takes you back to the Analysis Form dialog box.

From the Analysis Form a formatted version of the report could be generated by selecting “Structural Member Results” from the Output Reports drop down menu. This could then be printed directly or saved to a file using the commands on the File menu. Apart from the Building Analysis Results, various other reports are also available.


Click on the Reports tab.

As we have seen the analysis results report is available on the Post-Analysis tab, however all the other detailed output reports are available from here, For example:

Pre-analysis checks report: - a basic summary of the model input. Post Analysis Checks Report: - the horizontal displacement (drift) checks (Total and Relative). Analysis Model Echo Report:- the full analysis input data file. Storey Displacements Report: Orion calculates the displacements in the x and y directions and torsion for each load combination for each storey. Column Bracing (Sway) Classification Report: This report is based upon ACI code recommendations, and is not applicable if braced conditions have been manually amended. This option should only be used with cross reference to the ACI code. Beam Load Analysis Report: contains the beam loads. Each of these reports can be printed, or saved for later inclusion in a batch print out of all reports created by the program. They can also be exported to a variety of different file formats.

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4 Beam Reinforcement Design 4.1 Exercise Aims •

Review of Design Parameters

•

Designing all Beams using Batch Mode

•

Interactive Beam Design

•

Creating the Beam Elevation Drawings

4.2 Beam Design Settings and Parameters 4.2.1 Beam Design Settings Prior to performing the design it is recommended that you take time to consider the various settings and parameters that can be used to control it. Judicious use of these settings can have a big impact on the economy and practicality of the resulting design.


From the Main Menu select Settings/Beam Design Settings/Storey Beam Settings.

A brief overview of the options will be given by your trainer, but for further information regarding these settings please refer to the Appendices. The subsequent beam designs were undertaken with the Default Settings.

4.3 Designing all Beams using Batch Mode We will now design all the beams using the Batch Mode feature.


Go to the Main Menu and select Run/Beam Section Design and Detailing/Storey Beams so the following screen appears.

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Select File/Beam Reinforcement Design (Batch Mode).




Then using the ‘Re–select All Steel Bars’ option choose Analysis.




When the process has been completed, click Close.

The beams that have been successfully designed are now indicated in the table.

The batch design has been performed in accordance with the current beam design settings. These can be modified to suit the user requirements. If you re-run the building analysis after making any changes to the model and then go back into the beam design window, the colour of the design ticks will have changed. • Green tick = PASS • Red cross = FAIL • Yellow tick = Beam passed with previous analysis and design results, but they are not currently up to date. Results can still be accessed and used, but it is the users decision whether to do so

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Standard 4.3.1 Example View

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Standard 4.4 Graphical Review of Passing / Failing Members It is possible to review the design status of all members graphically. This is done by clicking on the Design Status tab located at the bottom of the Structure tree view.


Close the beam design summary and click the Design Status tab as shown.

Any failing beams would be highlighted in red




Select Run/Beam Section Design and Detailing/Storey Beams to redisplay the beam design summary.

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Standard 4.5 Interactive Beam Design Using the filter command beams can be listed in the design window, based on storey / axis or pass / fail status. Axes containing these beams can be filtered out as follows:


Click on the filter icon




Filter to display only the Storey 1 beams.

Only Storey 1 beams are now displayed.

4.5.1 Utilisation Ratios The beam design summary includes an utilisation ratio. This is the ratio of As_required/As_provided. Hence, if the utilization ratio is greater than one, then at least one of the beams on the axis is failing because it has insufficient area of steel. If the utilization ratio is less than one but the beams are still failing this will probably be because: •

The beams have insufficient width to accommodate reinforcement required

•

Or, the deflection is too great.

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Standard 4.5.2 The Axis and Beam Information Editor


Scroll down to locate the beam line on Axis F at storey 1, Part 1 by double clicking on it, or choose File/Beam Reinforcement Design, or click on the icon

The Axis & Beam Information window opens showing the beam dimensions and supports along axis F at storey 1.

Note: If the beam size is too small, changing the values displayed here can amend it. However, the Graphical Editor will need to be updated manually also.

The Design button shows design forces used to determine the required area of steel for the highlighted beam. Six values are shown representing the factored left and right end moments and the mid span moments at the top and the bottom of the beam. The left and right design shear force is shown also.


Click on the Design button.

Note: The user can manually edit the above design forces by simply typing over the displayed values. If this is done the Effects Manually Edited box would automatically become checked. If subsequently the box is unchecked, the values would revert to those that had been calculated by the analysis.

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Click on OK to exit without changing the design forces.

4.5.3 The Reinforcement Data Screen


To review and modify the reinforcement provided by the batch design click Steel Bars. This should then display the Reinforcement Data screen as below:

Any figures in red indicate a problem. In this case there is a problem with the spacing of the top bars in beam 1B18, the spacing is 63mm but the default minimum spacing is 70mm. A batch design will fail a beam if the min spacing requirements have been contravened at a beam end.

4.5.4 Beam Detail Drawings The above bar pattern is referred to as Standard Pattern 2. To see the beam detail drawing for it, click on the Beam Details button.

Standard Pattern 2

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Standard 4.5.5 Standard Bar Patterns The program has four standard patterns each of which is fully described in the Engineer’s Handbook. The different patterns can be tried by clicking on the drop down menu to the right of the Select Bars button as shown below.

Try this now to investigate the other bar arrangements, make use of the Beam Details button to see the differences between each pattern. Standard Pattern 1

Standard Pattern 3

Bent Up Bar Pattern

For this axis, none of the patterns automatically arrive at a satisfactory design; therefore it will be necessary to interactively adjust it.


Reselect the bars based on Standard Pattern 2, this was only failing in a couple of areas due to a bar spacing problems.

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Standard Note: In the Reinforcement Data screen, if you click OK to store a beam while there is still a bar spacing warning, the program interprets your action to mean that you have made an engineering decision to treat the current bar spacing as acceptable. Provided the utilization ratio is less than 1.0 the beam would now be given a pass status.

4.5.6 Modifying the Number and Size of Bars You can amend the bars provided by left clicking onto any of the reinforcement labels then use the left scroll bars to increase/decrease the number of bars and the right scroll bars to increase/ decrease the bar sizes. The extra area of steel As, the bar spacing s-Bar, and the deflection check are all automatically updated. Values shown in red indicate problems.


Modify the bar layout for 1B18 to increase the top bars to 2H20. This will increase the spacing to 134mm, which is greater than the minimum of 70mm but less than the maximum 140mm.

Alternatively you could amend the mimimum bar spacing value in the Beam Design Settings.

4.5.7 Bar Layers For beam 1B19, 1B18 & 1B19 the bar sizes could be rationalised by switching all the top bars to H20 but this would leave insufficient reinforcement at the left end of 1B19. This can be resolved by adding a second layer of support bars.


Change the Top bar for 1B19, 1B18 & 1B19 all to 2H20




Click beneath the Top Bar on 1B19, on the line for Sup.Top Bar

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Add 2H20 bars

This will cause an s-Bar (top) spacing error.


With these support bars still selected and click on the Bar Layer Tool to change to bars at layer 2 as shown below:

Bars placed in layer 2 are shown as dotted lines as shown.

Shown below is the amended beam detail.

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4.5.8 Modifying bar curtailment The Steel Bar Characteristics toolbar can also be used to amend the bar curtailment.


Click on the 2H20 Top Bars in 1B19 and change the right end for them by clicking on Extend Right to Short

The effect of this is shown as a shortfall in the required area of steel at the right hand end of the beam. As shown below.




Return to the original curtailment setting by changing back to Extend Right to Lap

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Standard 4.5.9 Beam Loading and Force Diagrams


To see the loading and forces, click on the Diagrams button.

Below are the diagrams that are obtained for this beam line (Solid lines G / Dotted Lines Q).




Exit from the diagrams then click on OK to store the interactively designed bar arrangement for this axis.

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Standard 4.6 Creating the Beam Elevation Drawings After designing the floor beams we will now create some Beam Schedule drawings.

4.6.1 Putting All Beams onto a Single Sheet Automatically


From the Menu select Sheet/Beam Detail Drawings of All Axes (Single Sheet)




Click on OK to accept 3 beam axes across the width of the drawing sheet

All the beams are placed onto a single sheet and a table of quantities is created as shown below

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5 Column & Wall Reinforcement Design 5.1 Exercise Aims •

Assigning Design Parameters

•

Designing all Columns & Walls using Batch Mode

•

Rationalising the Steel Bars

•

Creating a Column Schedule

•

Creating an Output Report

5.2 Column Design Settings and Parameters 5.2.1 Column Design Settings As with the beam design settings, judicious use of the column design settings can have a big impact on the economy and practicality of the design.


From the Main Menu select Settings/Column Design Settings.

A brief overview of the options will be given by your trainer, but for further information regarding these settings please refer to the Appendices. The subsequent beam designs were undertaken with the Default Settings.

5.3 Designing all Columns using Batch Mode Columns and walls can be designed individually, or all in one go using the batch mode option.


From the Main Menu select Run/Column Section Design so the following screen appears.

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Choose File /Column Design ( Batch Mode) in Column Design Reinforcement window




Ensure your settings are as shown above, and then choose Calculate.




After design is complete you could click on the Messages button to review the bars selected for each column for each combination.




Then choose Close to take you back to the Column Reinforcement Design window.




The same ‘traffic light’ system used for the Column Design Status. Green Tick – Pass, Red Cross – Fail, Yellow Tick – Results are not up to date for this element.

Note: A very low utilisation ratio can be displayed for some columns if the minimum steel is sufficient.

5.4 Creating a Column Schedule


From the File menu in the Column Reinforcement Design window choose Column Schedule.




Choose some columns to be placed on the schedule as shown. (Hold the Ctrl key down while selecting).

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Click on Draw to create the schedule.

Close the schedule and cancel to return to the Column Reinforcement Design window.

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Standard 5.5 Creating a Column Output Report The columns to be included in the report are marked by a blue tick in the Print column. Columns can be added or removed from the report using a combination of the icons Mark for Printing, (F7) Mark All Columns for Printing (Ctrl+F7) and Clear All Print Marks (Shift+F7).


Ensure all columns are marked for printing.




From the File menu in the Column Reinforcement Design window choose Column Reinforcement Design Report.

The Report can be sent direct to a printer, or it can be saved for later inclusion in a batch print out of all reports created by the program. It can also be saved in PDF format for sending to other computers on which the Orion program is not loaded.


Click on Save Report




Close the report and return to the Column Reinforcement Design window.

The ‘Column Reinforcement Design’ window can also be printed using the ‘Print Column List’ icon

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This report can then be printed.

5.6 Creating a Foundation Loads Report This report is created from within the Column Design Module. The report can consist of forces in all columns or only those at foundation level.


From the File menu in the Column Reinforcement Design window choose Column Forces Listing.

A dialog appears as shown allowing the user to configure the report as required. The List button will create the report in WordPad, from where it can then be printed.

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Click Close to return to the Column Design Module.

5.7 Interactive Column Design 5.7.1 Exercise Aims •

Understanding the Column Design Editor

•

Designing Rectangular Column

•

Column Slenderness

•

Column Interaction Diagrams

•

Manually Modifying the Bar Sizes

•

Fixing the Bar Layout

•

Link Arrangement

•

Shear Design

•

Manually editing the column size

•

Biaxial bending vs BS 8.1.1.0-Cl 3.8.4.5 design

•

Designing the Wall

5.7.2 Understanding the Column Design Editor To access the column design editor you must first select one of the columns.




Locate column 1C2 in the table




Either Double click on the column, or choose from the Menu File/Column Design or select the Column Design icon, so the Column Design Editor is launched

Column 1C2 is now ready for design as shown below.

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The combination highlighted ‘red’ is the critical design combination. The Column Design Editor screen contains the following information: Section: Section dimensions include the dimensions of the column (“b1” and “b2”), the eccentricities (“e1” and “e2”), the column clear lengths (“L1” and “L2”), and the concrete cover. If you modify these fields, you have to click the “Update” button to apply the changes. Bending: Column design can be performed under uni-axial or biaxial bending. According to the member type, dimensions and member forces, Orion selects the bending type automatically. But, the user can change the selection by clicking another option before the design procedure. Load Combinations Table: The program will always design for all load combinations. At the end of the design it will highlight the critical combination. Member force results from each load combination during the Building Analysis procedure are listed in a table.

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Standard Fields in this table are: Load Combination N M1 M2

Load combination used in the Building Analysis Axial force result from the load combination displayed on the same line. Bending moment in local 1 direction (bending around Dir 2 axis) Bending moment in local 2 direction (bending around Dir 1 axis)

In the design procedure, member force results from each load combination will be tried one by one. The critical combination will be identified and used to select the reinforcement area. Reinforcements Table: This table contains several items of information: 1. Steel Bar Quantities and Diameters According to the steel area required, bar sizes are selected by the program automatically. The user can then modify the selected bar sizes by considering the steel area required. 2. Required As After design the steel area required will be displayed at the bottom of the table. 3. Sufficient As When the design procedure is completed, the steel area supplied will be displayed at the bottom of the Reinforcements table. 4. Links You can view the links selected for the current column in the “Links” page. 5. Shear Design Shear forces on the section and the links provided are displayed in the “Shear Design” page. 6. Slenderness This page can be used to indicate the column as braced in one or both directions.

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Standard 5.7.3 Designing Rectangular Column


Select Design to perform the reinforcement design

The Column Reinforcement Design window should now be as shown below.

Note: Because the BS8110 method is used the neutral axis will be horizontal or vertical depending on which axis has the greater design moment. If the Bi-axial design method had been used the neutral axis would be at an angle




By selecting the Design Report option, the design for an individual column can be viewed.

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Choose Close to exit back to the Column Design Editor.

The column has been designed using 8H12 bars and combination 1 G+Q *F is the most critical.

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Standard 5.7.4 Column Slenderness A column may be considered braced in a given plane if lateral stability to the structure as a whole is provided by walls or bracing designed to resist all lateral forces in that plane. If you check the “Control Braced Condition Manually” option in the Project Parameters form, then you can specify the bracing condition for the X and Y directions manually. Otherwise Orion checks the bracing for each direction automatically based on the drift of the storey levels. But in both situations, you can change the bracing condition for a single column in the “Slenderness” page. The “beta” value is determined separately for braced and unbraced columns and additional moments will be calculated accordingly.


Click on the Slenderness tab in the Reinforcements table.

The column is currently set as braced and because it is being classified as short, no additional moments are being added to the initial moments.




Try un-bracing the column in the both X and Y directions and redesigning. You should find that this results in the column being classified as slender and consequently additional moments are added. The column has now been designed using 8H20 bars.

5.7.5 Column Interaction Diagrams After the determination of the column reinforcement, Column Interaction Diagrams can be prepared. Using the interaction diagrams, a better understanding of the behaviour of the column can be achieved. Column interaction diagrams can be drawn using the "Column Analysis" button.


Click on the Column Analysis button at the bottom of the Editor.

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Column Axial Capacity Column Critical Axial Load

The red line is the Dir 1 column capacity and the blue line Dir 2. Also plotted are the top and bottom moments determined during the analysis of the building for each of the combinations. The horizontal red line indicates the axial load limit determined by the code. It can be seen that the design moments are very close to the moment capacity in dir 2.

The blue line on this diagram shows the M1-M2 capacities at the given axial load level.


Click on Close to return to the Editor.




Reduce the size of the corner bars to H10 as shown below. Note that the provided (sufficient) area is now less than the area required.

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Click on the Column Analysis button once more. Note that although the analysis moments seem OK, when you display the design moments some of the results are plotted outside the interaction line, indicating the column fails.

5.7.6 Fixing the Bar Layout The design method is currently set to maximise the bar spacing. However it is possible to perform the design with a fixed bar layout.


Click on the Parameters button at the bottom of the Editor and change the design method to Fixed Bar Layout.




In the Steel bars table enter the quantity for 1-int bars as “3” as shown (after changing the value ensure you click on another cell to register the change). The bar layout is fixed, so that you obtain 3 bars in the 1-int direction.




Design once more.

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A sufficient area of steel has been obtained, however it is perhaps on the heavy side.

5.7.7 Link Arrangement You can view the links selected for the current column in the “Links” page. When the “Links” page is selected, the edge numbers of the column will be shown in the sketch which will help you to follow the links described. Note: Link spacing for the supports and the span are calculated separately. If you want to use the same spacing both for the span and the supports, uncheck the “Create Support Regions for Links” option under the “Settings and Parameters” menu of the “Column Reinforcement Design” form. If you want to delete the support regions only in the current column, you can simply copy the size and spacing of the links calculated for the span to the supports in the “Shear Design” page. You can select other types of link, such as “Cross Link” or “Double Links”, from the “Links Pattern” window in the “Links” page.

5.7.8 Shear Design Shear forces on the section and the links provided accordingly are displayed in the “Shear Design” page. The Shear Force calculated in the Building Analysis (Vd), Concrete Shear Stress (vc) and Limiting Shear Stress (vl) can be viewed in this page. These values can not be edited. Size and spacing of the links selected are displayed on the right of the page. Links for the span and for the supports are given separately. Size and spacing of links can be edited on this page. If you press the “Calculate” button after selecting a new size, a new spacing will be calculated accordingly.

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Standard The number of link arms provided in each direction are given in the “No. of Link Arms” fields. If a standard link type is selected then these numbers will be determined by the program automatically. But if you want to describe a special link, you can write the number of link arms into these fields.




Click on OK to save the modified design for column 1C2 and return to the Column Reinforcement Design window.

5.7.9 Biaxial bending vs. BS 8.1.1.0-Cl 3.8.4.5 design The program gives the user the option to carry out column design based on a True biaxial bending approach (referred to in Orion as the Bressler Method). This is simply a "first principles" approach to section design - see BS8110 clauses 3.8.4.1 and 3.4.4.1. This “first principles” approach is required for dealing with irregular column sections. The approach used is covered in most concrete design text books - e.g. "Reinforced Concrete Design" 4th Edition (1990) by W.H.Mosley and J.H.Bungey. In fact, the simplified equations and charts in BS8110 for rectangular / circular sections are all derived from this basic set of “first principles” - see appendix A in BS8110 Part 3. The column designs carried out so far have all been to the traditional BS 8.1.1.0-Cl 3.8.4.5 “codified” approach. Engineers may like to use this method, as it's easy to check directly against handcalculations, but remember you cannot use this method for the irregular shaped columns.

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Standard 5.7.9.1 Designing the Wall


Select 1W1 from the Column Reinforcement window




Then click on the Column Design button to perform the wall panel design as shown below.




Choose Close to get back to the Column Editor




Select OK to get to the Column Reinforcement Design window as shown below.

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Standard 5.8 Creating the Column Reinforcement Plan


Return to the Graphic Editor and go to St01.




Then select the Column Application Plan view by clicking on the tab at the bottom of the structure tree




Select column 1C2 at Grid B/2,




Then right click to display the pop up menu as shown below.

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From this menu choose Column

Links




then indicate where you want the shown below.

links to appear on the drawing as




Right click, and pick Arrange Steel Bars / Position Steel Bars. This adds a bar mark for each bar on the drawing.




Then Right click again, and pick Arrange Steel Bars / Steel Quantity Table




Then click on any point in the Graphical Editor where you want the table to be placed.




Repeat this for the Column Steel Details

So your screen should look as follows.

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Column Reinforcement Plan for 1st Storey This drawing can be edited and plotted directly from here. Alternatively it can be exported by clicking on the DXF Export icon and then opened and edited further in AutoCAD.


Select the Form Plan

to take you back to the Graphical Editor.

The Lateral Steel of All Columns can be displayed using the following option:-

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6 Slab Design and Detailing 6.1 Introduction Note: This process uses the slab coefficient method from the tables in BS8110. This is independent of the general building analysis and can therefore be carried out before or after the general building analysis. This method takes NO account of openings or concentrated point/line/patch loads on the slabs. This chapter covers the following: •

Slab Design Settings

•

Creating Slab Reinforcement Strips Horizontal & Vertical

•

Creating a Slab Reinforcement Output Report

6.1.1 Slab Design Settings Bar spacing increments, top steel extension lengths and other slab design preferences are set in the Graphical Editor Settings / Slab Reinforcement 1 tab.




Set the Steel Bar Spacing Step to 25mm as above to ensure that all bars within the slab will be at multiples of 25mm. In addition, as shown above, the bars will be spaced at no less than 125mm and no greater than 250mm.

Additional slab steel detailing preferences are controlled via the Graphical Editor Settings / Slab Reinforcement 2 tab.

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In the Graphical Editor Settings/ Rbar Labels tab you can customise the bar labels to suit your user preference. Various different formats are available. (e.g. Where Orion shows 21 H10-300 this can be changed to just H10-300 if desired).

6.2 Create Slab Reinforcement Strips


From the Structure Tree double click on Storey: St01 to return to the 1st Storey.

Note: For clarity, the slab yield lines can be switched off while placing slab strips. To do this select View/Graphical Editor View Settings and then on the Slabs tab uncheck the box Display Yield Lines. Slab reinforcement is determined by inserting slab strips in the X & Y directions, which will automatically determine the reinforcement required based on Table 3.14 from BS 8110. To obtain correct results it is essential that the slab types have been correctly defined. The strips parallel to the horizontal direction axes will be labelled X1, X2 etc and those parallel to the vertical direction axes will be labelled Y1, Y2 etc. We will first enter a strip labelled X1 through the slabs between Grids A-B/1-5.


Click on the Slab Strip icon

The Slab Strip Properties should be displayed. When drawing the strips it is essential that the correct start and end conditions are specified. The three options being:

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Standard Slab

The strip starts or ends inside a slab. The bottom steel for the slab in question is not designed, but the span of the slab can be defined and this value is used in determining the support steel.

Bob

The strip starts or ends beyond an edge beam or wall. The support steel at the edge is bent down into the beam/wall.

Cantilever

The strip starts or ends beyond a cantilever slab.




Ensure the label is X1 and indicate a Bob at both the start and end of the strip by clicking on the appropriate end conditions as shown on the right.




Then position your cursor above Grid A but to the left of Grid 1 so it is not in the model, then press and hold the CTRL key and at the same time click and drag in a horizontal line from Grid 1 to past Grid 5

So your screen should look as follows:




Create another similar strip labelled X2 by repeating the process between Grids B-C/1-6.

Note: When placing strips you may encounter warning messages similar to the one above. Although the steel provided is sufficient for strength it is failing the span/effective depth check deflection check. This problem will be resolved later by editing the bar layout or changing the slab depth.

Note: Although only two strips have been created in the model in the X direction, strips for all slab panels / conditions should be created to complete the floor design in both the X and the Y direction.

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Standard Now some vertical strips will be inserted.


Create strip Y1 from Grid 1-2/A-F but note that the slab at Grid F is a cantilever slab so the end condition for strip Y1 in the toolbar needs to be changed to cantilever.

If you drew the strip Y1 and you received a warning message as shown below, this is because the strip has failed to satisfy the L/d deflection check. L is calculated at exactly the point where you cut the strip.

After creating the 3 strips your screen should look as shown below.

Slab Designed to Table 3.14 Note: This slab detail drawing can be exported to AutoCAD using the DXF export command.

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Standard 6.2.1 Filtering the Display of Slab Reinforcement (for information) By ensuring that when drawing horizontal strips, the strip name begins with X and when drawing vertical strips the strip name begins with Y you will have flexibility to filter the display of X steel, Y steel, top steel or bottom steel.


Pick View/Graphical Editor View Settings and click the Slabs tab.




Try switching off the Y steel and Top steel as shown above.

6.3 Editing the Bar Layout By right clicking on a reinforcing bar you can select and load the bar properties. You can then edit the bar spacing and diameter as well as the rebar location on the drawing.


Select the bottom bar running horizontally across slab 1S6 and display its properties as shown.




Clicking the Update button causes the slab strip to be automatically rechecked. If it is failing in deflection try increasing the bar diameter and updating again until it passes.

Note: The Steel Bar Property dialog also contains icons for editing/moving the bar span marks and moving the steel bar. These can be used for improving the drawing layout. Page 120

Standard 6.4 Creating Slab Output 6.4.1 Output for an Individual Slab Strip It is possible to see the calculations for an individual strip.


Select strip X2 and then right click to display the pop-up menu.




Choose Slab Strip Check Design. This displays the calculations for the X2 strip only.

6.4.2 Creating a Slab Output Report for the Entire Floor


Choose Slab Analysis and Design from the Run menu in the Main Menu bar.




Click on the Calculate button to generate an output report.

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Standard A Preview of the Slab Report is displayed. Options are available to configure and then print it. You can also save the report in a number of file formats.

6.4.3 Table of Quantities The Table of Quantities for the slab strips can be created as follows:


Right click, select the Arrange Steel Bars/Steel Quantity Table




Click to the right of the building, where you would like the table to be located on the drawing sheet.

Steel Quantity Table for Slabs Note: The quantities in this table will only reflect the number of strips cut in the model. It is the users responsibility to ensure the sufficient strips have been cut to achieve the accurate quantity.

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7 Creating a Flat Slab Model 7.1 Introduction This chapter covers the following: •

Creating Flat Slabs

•

Creating additional Storeys

•

Editing a Flat Slab Model

7.2 Creating the Flat Slabs in the Model


Click Open and select model ‘Training_Course_Model_1a’.




Click File > Save Project As and rename the model Training_Course_Model_1a_(your initials)

Flat Slabs in Orion are modelled using the Slab Icon, however as the slabs are no longer bound by beams the Type option will not be relevant as the flat slabs can no longer be designed using Table 3.14 co-efficients from BS8110. For all Flat Slabs panels they should be inserted using Type 1, the continuity of slab edges sharing the same axis will automatically be generated in the Finite Elements Model.

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Standard Before creating the slabs in a Flat Slab model it is paramount that the layout of the slab panels is given consideration, and the following guidelines are met:


All columns and walls must lie on slab boundaries




Slab boundaries sharing the same grid line will be continuous in the FE model




Slab panels should be as large as possible (Lots of small panels will complicate the FE)




Slabs should have the minimum edges possible (triangle/square/rectangle). Irregular shaped panels L etc. should be avoided




There is No Right or Wrong layout for the slab panels, but by adhering to the above, slab layouts should be simple and effective when entering the FE environment

7.2.1 Inserting the Slabs


Left Click on the Slab Icon, entering the values for a Type 1, 300mm thick slab with 25mm concrete cover




Left Click on the Loads Tab entering values of 0.5kN/m2 for additional dead load and 2.5kN/m2 for imposed load




Left Click on the Insertion tab, and choose the Axis Region for the Slab Insertion method. Note as there are no beams in the model, the Beam Region (Default) method cannot be used.

Note: The use of the other slab insertion techniques will be introduced during the Day 2 training.


Hold down Ctrl and left click in the area bound by axis A/B, 1/2, you will see a red box appear showing the slab perimeter

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Continue to hold down Ctrl whilst left clicking in the area bound by axis B/C, 1/2 and C/D, 1/2, you will note the red slab boundary increasing in size with every click




Create all the slabs on St01, using this technique until your model has the same slab configuration as shown below:-

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Standard Note: If any of the slabs have been created overlapping the columns rather than having a slab boundary run through their insertion axis, this will be picked up in the ‘Building Model and Validity Checks’ These checks can be performed at any time prior to the Building Analysis.

7.3 Creating Slab Loads and Openings 7.3.1 Slab Loads It is possible now the slabs have been inserted into the model to create Line / Point and Patch loads directly onto the slab. To demonstrate this we are going to place a Line Load on the perimeter of the slab.


To aid in the selection of the correct location of the line loads, it may help to switch the Axis Layer off, using the Axis Layer Toolbar




Left Click on the Slab Load Tool, and specify a Line Load of magnitude 10kN/m for the Dead Loads only.

Note: Point and Patch loads can also be applied to the slab using the same techniques. If a dxf had been imported into this model it would be possible to snap onto the shadow, to enable to accurately model the location of any additional loads on the slab, such as a corridor or plant room.

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Left Click and drag to define the line loads around the perimeter, taking care to snap onto the slab corners.




As the line load has been created over more than one slab a warning will appear, asking you to confirm this was your intention, Click OK




Place the remainder of the loads around the perimeter, as shown below:-

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Standard 7.3.2 Slab Openings Now we will create some slab openings


Click on the Slab Opening icon or go to Member/Slab Opening




Enter the size of the opening as follows b1=500, b2=1000




Enter the distance away from the grid where it is to be inserted as e1=1000, e2=1000




Then click the grid intersection D/1

The opening should now appear as shown below.

Note: Slab openings can be created circular or at an angle for rectangular/square openings. All slab openings must be created using positive values for the e1 and e2 offsets from grid. All holes must be created within a single slab panel.

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Standard 7.4 Creating Additional Storeys 7.4.1 Storey Information As we did in this mornings exercise for a Beam and Column Structure, create a 4 storey model which has the following parameters:


St04

Copy of St01 excluding Slab Loads and Slab Openings Create a Type 1 – 300mm thick slab to the top of the shear core




St03

Copy the Storey Information from St01 to St03




St02

A duplicate of Storey 3 (St03)




St01

Original Storey – No editing necessary




Storey Height for all floors is to be 4000mm

Duplicate Storeys – The use of duplicate storeys should be used wherever genuine duplicate floors exist within the model. The benefits as explained in the Beam and Column example still exist, but also when performing the Finite Elements Load Chase down, duplicate storeys will not need to be reanalysed, therefore speeding up the load chase down procedure. Unique Storeys – There will always be a minimum of 3 Unique Storeys in any multi-storey structure (shown by the Blue Dot by the side of the Storey Label in the Workspace area). •

St01 – The first floor generated in the model

•

Top Storey

•

Penultimate Storey

Note: The top and the penultimate Storey cannot be identical, as the columns / walls at the top floor, only project below the floor plate. Where as, the lower storeys all have columns / walls which project above & below the floor plate which will effect the moment distribution from the slabs to the supporting elements.

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Standard

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8 Building Analysis for Flat Slab 8.1 Pre-Analysis 8.1.1 Exercise Aims • • • •

Model Validity Checking Run Building Analysis - Pre-Processor Run Building Analysis - Post-Processor Viewing the Analysis Output Report

8.1.2 Pre-Analysis - Model Validity Checking


From the Run menu choose Building Analysis. This should then display the Analysis Form.




We are going to use the same settings as used for the Beam and Column example, so there is no need to make any changes to the Parameters / Storey Loads Editor / Material Grades, Click Model OptionsModel Options

8.1.3 Model Options Settings


Click on the Settings tab There is a change in the Building Analysis > Analysis Form > Model Options > Settings The change is for the ‘Storey Weight and Centre of Gravity’ calculations. With the beam and column example all the slabs were supported by beams, therefore the load could be decomposed from the slabs to the beams. The use of ‘Decomposed Beam Loads’ could be relied upon to generate the Storey Weight and Notional Horizontal Forces for the structure. However, in a Flat Slab Model no beams (or very few) exist, therefore the ‘Undecomposed Slab Loads’ have to be used to correctly calculate the Storey Weight and Notional Horizontal Forces. If the incorrect setting is made, the user could significantly underestimate the Storey Weights and the effect of Lateral Loads on the structure.

Slabs are not modelled in the Building Analysis, which goes some way to explaining why the Undecomposed Loads must be used for Flat Slab Models. Slabs are replaced by a series of Diaphragms (based on the user’s settings) within the Building Analysis, but are able to transfer gravity loads to the columns and walls.

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Standard 8.2 Performing the Analysis 8.2.1 Pre-Analysis – Model Validity Checking




Click on Building Model Validity Check.

This will check that the building is valid for those conditions indicated. The ‘Check Columns Inside Slab Panels’ will check for slabs which have been defined incorrectly. If a column exists within a slab, rather than on slab boundary an error will be reported.

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Standard





Choose All Storeys and then click on the Check button.

Assuming that no errors are reported, close the dialog

Note: During the Building Analysis, the Lateral Loads for the model will be generated. There are NO Supporting Beams for the slab loads to be distributed onto. Therefore, ONLY THE LATERAL FORCES will be correct after the Building Analysis has been performed. THE GRAVITY LOADS WITHIN THE MODEL WILL BE INCORRECT, this will become apparent when viewing the ‘Axial Load Comparison Report’.





Ensure the Column/Wall Reinforcement Design and Beam Reinforcement Design is Unchecked before clicking on Start to begin the batch analysis process.

Click Start to begin the Building Analysis Calculation, and a warning message should be displayed.

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Standard The warning shown above indicates that Gravity load has gone missing. This is because there are no beams in the model for the slab loads to decompose onto. This illustrates that an FE load chase down is always required to obtain the design forces for the member design for flat slab models.

8.2.2 Checking the notional horizontal forces Once the beam load calculations have been performed, the weights of each storey can be viewed and if lateral loads were specified in the Project Parameters they can be viewed and edited. Remember these values were calculated using ‘Undecomposed Slab Loads’


Return to Pre-Analysis and select Storey Loads Editor.




Click on Cancel to leave the notional forces unchanged.

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Standard 8.3 Post-Analysis 8.3.1 Cross Checking the Analysis Result As we found in the previous example the Axial Load Comparison Report is a good way of investigating how the load is being decomposed throughout the structure.


Go back to the Analysis tab




Select Axial Load Comparison Report

The total ‘SUM OF APPLIED LOADS (Using Un-Decomposed Slab Loads)’ values should be similar to those from the Decomposed Slab Loads table if the Building Analysis Results are to be correct. It should be clear from this report that vertical load has gone missing; therefore the gravity results due to the Building Analysis will be meaningless. This again emphasises the fact that an FE load chase down is required.

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Standard 8.3.2 Model and Analysis Results Display The Analysis results can be viewed graphically again, but the only results of any significance will be those for Lateral Loads – NHF’s / Wind etc.


Click Model and Analysis Results Display

The diaphragms formed during the analysis can be viewed along with the Major Axis Moments and displacements for Fx or Fy.

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Standard

The frame sways under the lateral loadcase Fx as shown below:-

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Standard

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9 Gravity Load Chase Down using Finite Element Analysis 9.1 Exercise Aims •

Finite Element Analysis Options

•

No of Plates & Mesh Uniformity Settings

•

Analysing a Single Floor

•

Completing a Batch Load Chase Down

•

Checking the results

•

Merging the Column Results

9.2 Finite Element Model Generation Options


From the Run menu choose FE Floor Analysis

.

Column/Shear Wall Model Types – There are 3 options held within this menu, but only the ‘Short Frame Model’ includes the columns and walls within the FE analysis. This enables moments to be transferred from slab to columns/walls; this option is also required to perform a load chase down.

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Standard Beam and Slab Stiffness Multipliers – As the FE model is based on actual stiffness’s of all the beams columns walls and slabs any change to the Slab or Beam Stiffness Multipliers will effect the results. How to use these Multipliers effectively is discussed in the Engineers Manual. Include Column Sections in FE Model – Checking this option allows the physical dimensions of the columns to be included in the FE model, by using a series of Rigid Arms, instead of simply modelling to the member centrelines. This will reduce the high peaking hogging moments over supporting columns for a Flat Slab design. Include Slab Plates in FE Model – For Flat Slab Models you must check this option. For Beam and Slab Models if this option was un-ticked, it would allow a load chase down to be performed based on the beam load decomposition technique derived for the Building Analysis (Yield Line or FE for Beam Loads). Consider Beam Torsional Stiffness – If included then hogging can develop in the slab adjacent to the perimeter beams. This must also be included if any slab within your model relies upon the torsional capacity of a beam within the model for its support. Torsional values will be calculated; however Orion does not consider Torsion within the Beam Design. Include Upper Storey Column Loads – If you wish to chase the load down through the structure this option must be selected, even at the top storey. This will allow the transfer of load and column / wall self weights, from floor to floor during the analysis process. For the purpose of this example the following settings will be applied at St04:-

Note: For a load chase down to be successful the structure must be analysed from the top floor down and in sequence, but excluding duplicates ie. St04 / St03 / St01. If this sequence is not in order when the ‘Include Upper Storey Column Loads’ is selected, then the following Warning will be displayed.

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Standard

1.

Mesh and Analyse the Top Storey, to generate the Column/Wall forces.

2.

Mesh and Analyse the Penultimate storey. Reactions form the floor above becomes applied loads on the floor below.

3.

Continue this process floor by floor down through the structure (excluding duplicates)

4.

Mesh and Analyse St01 to chase the load down to foundation level.

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Standard Note: The Slab Stiffness has been altered (0.25) to allow analysis results to be viewed for the Long Term Modulus of Elasticity (E) of the slabs. Within Orion there are various ways these adjustments can be achieved, which will effect the results, these techniques will be discussed during Day 2 training, or by referring to ‘The Concrete Centre Publication – How to design reinforced concrete flat slabs using Finite Element Analysis – O Brooker May 2006’ 5.

If no adjustment is made to the slab to allow for the Long Term effects in the slab analysis, you will be warned before allowing entry into the FE Floor Analysis.

9.3 Generating/Performing the FE Analysis Model 9.3.1 Creating the FE mesh for Analysis


Ensure you are at Storey St04 and click Floor Mesh and Analyse

No of Plates – The more plates you have in the model the longer the analysis will take. We recommend a minimum of 6-8 plates is achieved between column support locations. The Default number of plates is simply 100 per slab, this is normally sufficient to provide the minimum of 6 plates between supports. Mesh Uniformity – The higher the mesh uniformity the more equal in area all the plates become, with the exception around columns for certain locations / geometry. This option becomes particularly useful for generating more concentrated analysis results close to slab openings.
Note: Finite Element Analysis is ONLY used for the determination of Gravity Loads on the structure, hence ONLY G (Dead) and Q (Imposed), will be available in the Loading pull down menu.

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Standard Click Generate Model with 1100 plates and Mesh Uniformity Factor of 50%

This maintains 6-8 plates between each of the column locations; note the difference below for Mesh Uniformity Settings at 100% and 50%. Only by using 50% can the 6 plates be generated between the columns on the top right of the screen, alternatively more plates could have been added to the model.

100% Mesh Uniformity Factor

50% Mesh Uniformity Factor

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Standard Note: Within the FE model the plates have been formed around the column heads, this is due to ticking the option within the FE Analysis Form ‘Include Column Sections in the FE Model’. Although this option allows the physical dimensions of the columns to be modelled in the FE environment, this does rely upon a more complicated mesh being formed around the column heads.

9.3.2 Performing the Batch FE Load Chase Down


Left Click on the Batch FE Chasedown

You will see as St04 has already been analysed a green tick appears beneath the analysis status.


Left Click on the Number of Plate Elements Text, without clicking anywhere else Type 1100, then hit Return this will change the number of plates to all floor levels to be 1100. This can be done for all settings in the Batch FE Chasedown Window.




Ensure the Include Slab Plates in FE Model is ticked on for all floors




Set the Mesh Uniformity Factor to be 50% (0.50)




Ensure the Include Column Sections in FE Model is ticked for all floors




Set the Slab Stiffness Factor to be 0.25 for all floors




Set the Beam Stiffness Factor to be 1.00 for all floors




Ensure the Consider Beam Torsional Stiffness is ticked for all floors

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Standard When complete the window should look as follows, make sure the Include Upper Storey Column Loads is ticked:-




Click on OK to Proceed with the FE Batch Load Chase Down




The Pause to Check Mesh at Each Floor has been Unticked, this is because we have checked and approved the mesh at St04, therefore all storeys should be satisfactory with the settings applied in the previous window. Note:Although in today’s example we are choosing not to Pause at Check Meshing at Each Floor, it would be strongly recommended that this option is left ticked for the first analysis run so that the user can satisfy themselves that the mesh is adequate at every floor in the model.

Page 146

Standard Orion will now Load the Pre Processor, Form the mesh at each floor level, and analyse before moving down to the next floor. This operation could be performed manually by forming the mesh and analysing each floor, and then selecting the floor level below, excluding duplicates. When the FE Batch Load Chase Down is complete a screen will appear to inform the user of the Maximum Positive and Maximum Negative Displacements at each of the floor levels. Excessive deflections would be an indication that the slab thickness is not adequate, or there is an error in the model. All deflection results are based upon the Slab Stiffness Multiplier (SSM) applied in the ‘Batch FE Chasedown Window.




Click OK to close this window




Click Close in the Finite Element Analysis Form, only when the Merge the Column box is ticked.

Note: The Merge Column Results with Building Analysis, is only required to be done once at any level within the model. When choosing this option ALL the G & Q results will be replaced on every level throughout the structure. At any time you can quickly toggle between the Building Analysis and FE Analysis Results, by ticking / unticking this option. The same principles would apply should we have any Beams within the Model.

Now we have two sets of results for the Gravity Loads in the model (G & Q), we must choose which results we are going to use for the design of the Columns (and Beams if applicable). For all Flat Slab models the results from the FE Analysis should be used, for obvious reasons. Merging the column results will Replace the G and Q loadcases from the Building Analysis to form a complete set on Analysis Results. The lateral results from the Building Analysis will still be used for the design. Only when the Merging process has been completed will we be able to design our columns and walls.

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Standard This will become obvious if the Display Analysis Results in Plan View in the Graphical Editor View Settings is switched on to display LC1: G, LC6: Q, Cmb1: (G+Q)*F




Click Graphical Editor View Settings > Columns and Walls, tick the Axial Loads, LC1, LC6 and Cmb1

Now view the Axial Loads for Column 1C1 at level St01. To do this un-tick the Merge Column Results, found in the FE Analysis Form > Analysis Post Processing and Reports.

These are the Building Analysis Results; hence the Axial Loads are INCORRECT. The loads shown will reflect only the Self Weight of the Column or Wall, rather than any decomposed load from the slabs to the columns.

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Standard

Now view the Axial Loads for Column 1C1 at level St01.

These are the FE Results for G and Q, which have now Replaced the Building Analysis Results, therefore CORRECT.

The Cmb1 load includes for the Imposed Load Reductions – if applied.

9.4 Cross checking the Finite Element Results The FE Analysis results should be cross checked the same way as was done for the Building Analysis results, via the Axial Load Comparison Report. Note:When the FE chasedown is complete from roof to St01 an extra table is added to this report (table 4), containing the FE Analysis Column/Shear Wall Axial Loads. The sum of these loads should equate (within a few percent), to the sum of all the dead and live loads applied at each storey level. If they do not the reason for the discrepancy should be investigated.


Click on Run menu and choose Building Analysis




Click on the Analysis tab and select Axial Load Comparison Report, check Table 1 against Table 4.

The updated Axial Load Comparison Report is shown on the next page. Table 4 is now shown listing the results for G (dead) and Q (imposed) at each floor level for the FE Axial Load Chasedown.

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Standard Axial Load Comparison Report Table 1 – Undecomposed Slab Loads

Table 4 – Finite Elements Analysis Column/Shearwall Axial Loads

Note: There will always be a slight variation in Table 1 and Table 4, this is due to the FE analysis being performed on a centreline model, and therefore slight overlapping of the slabs and the beams/walls will occur. There will also be differences due to the fact that the Building Analysis does not include the slab elements, hence any openings will not be considered within Table 1. Tables 2 & 3 are to be DISREGARDED, as there is no beams in the model for the slab loads to be decomposed onto, the results in Tables 2 & 3 are meaningless in a Flat Slab Model.

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10 Designing the Flat Slab 10.1

Introduction

This process uses the Finite Element results to determine the bar sizes required for the reinforcement of the slabs. This chapter covers the following:-

10.2

•

Using the Post Processor

•

Reviewing the Results and Contours

•

Creating User Defined Contours

•

Exporting Contours to DXF

Finite Element – Post Processing Settings




From the Run menu choose Finite Element Floor Analysis




Click Analysis Post-Processing and Reports




Ensure St04 is selected and a Positive (sagging) Moment Factor of 1.2 is entered prior to viewing the Analysis Post-processing.

Note: FE floor models do not include for any pattern loading. It is not feasible/logical to automate pattern loading to generate every possible worst case scenario, far every conceivable irregular arrangement and any size of model. A more realistic use of these adjustments is to amplify the sagging moments (by using a positive moment factor of perhaps 10-20%).

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Standard


Click on the Analysis Post-processing button

10.3

Floor Analysis Post Processing

This takes you through to the Post Processing window.

10.3.1

Deflection Plots These buttons allow the display of Displacements and the Contours.

The first option Display Displacements shows the displacement diagram of the mesh, for the selected storey.

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Standard The second option Display Contours shows the contours of the selected Loading and Effects

Note: The displacements shown in the contour plots are based upon the adjustments made in the FE Analysis Form for the Slab Stiffness Multiplier (SSM), to allow for the effects of Long Term effects due to (Creep, Cracking and Shrinkage).

Negative values of Deflection are for sagging, where as positive values are for hogging in the slab

The Displacement Contours are for the selected Loading, either G or Q unfactored, or G+Q*F which are factored results

If the contour plots for Deflection either do not make sense (i.e. maximum sagging is not where you expected etc..), or are experiencing excessive deflection, this would be an indication that the structure is not properly modelled or the slabs are not of adequate thickness.

10.3.2

Loading and Effects Toolbars

•

Left Click on the Loading tab and you will be able to select the following:-

•

G – This is an Unfactored Loadcase

•

Q - This is an Unfactored Loadcase

•

G+Q*F – This is a Factored Load Combination, therefore remember whenever looking at the Deflection Plots the results need to be de-factored

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Standard


Left Click on the Effects tab and the following options become available:There are various different Effects which can be viewed in the Floor Analysis Post Processor. These display, Global and Local effects, along with the Displacements / Moments / Area of Steel Requirements for the selected floor plate.

10.3.3

Loading and Effects

Mx

These contours are displayed relative to a single global coordinate system. If you imagine the X direction Bars running from left to right in the plan view, then the Mx moments are the design moments that these bars will need to be designed to resist.

My

These contours are displayed relative to a single global coordinate system. If you imagine the Y direction Bars running from bottom to top in the plan view, then the My moments are the design moments that these bars will need to be designed to resist.

Mxy

Average Nodal Torsional Moment (Wood & Armer Adjustments)

M1

Average nodal moment along Direction 1 (the Local coordinate system for the slab). By Default Direction 1 will be 0 degrees.

M2

Average nodal moment along Direction 2 (the Local coordinate system for the slab). Note Direction2 is always perpendicular to Direction 1.

M12

The average Nodal Torsional Moment relative to the Local coordinate system (Wood & Armer Adjustments)

As1-bot

Required steel area in the bottom face of the slab along Direction 1

As2-bot

Required steel area in the bottom face of the slab along Direction 2

As1-top

Required steel area in the top face of the slab along Direction 1

As2-top

Required steel area in the top face of the slab along Direction 2

Note: Any contour plot which displays a d within its name allows for the effects of Wood and Armer adjustments. Example Md1 or As(d)1 It is recommended unless you have a specific reason for ignoring the Wood and Armer adjustments you should ALWAYS work with the Md and As(d) results.

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Standard Wood & Armer Adjustments These adjustments take plate torsional moments into account to generate adjusted design moments. If a detailed background of these adjustments is required then reference should be made to the original papers:-

Wood, R.H.

“The reinforcement of slabs in accordance with a pre-determined field of moments” as published in Concrete 2.Feb 1968, pp69-76

Armer, G.S.T. “Correspondence” as published in Concrete, 2 Aug 1968, pp319-320 Md1-bot are the sagging Moments in the bottom of the slab in Direction 1 which include for the effects of Wood and Armer adjustment As(d)1-bot (shown below) are the area of steel requirements (based on the Effective Depth) in the bottom of the slab in Direction 1 which include for the effects of Wood and Armer adjustments.

Note: Hogging Moments will be denoted with negative values. Sagging Moments will be denoted with positive values. All Area of Steel values are based upon mm2/m In any of the Contour plots the mouse pointer can be used to highlight any node and the precise information about that node is displayed in the bottom left of the window.

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Standard 10.3.4

Setting the Concrete Effective Depth

Orion allows the user to set the Effective Concrete Depth, these settings will determine if the horizontal bars (in plan) are to be located on the outer or inner face of the concrete. This option also allows the user to set the concrete cover which will then automatically calculate the effective depth for the generation of the contours, and determine the area of steel requirements.





Right click anywhere in the FE Post Processor Window, and select Concrete Effective Depth

Click on the Concrete Cover (to Bar Face) and type 25mm


Ensure the Dir 1, is set to Layer 1 (Outer) – this will then place the horizontal bars (in plan) in layer 1 i.e. the bars nearest the upper and lower surface of the concrete.


Set the Bar Diameter in Dir 1 and Dir 2 to be H16




Click OK

All of the Area of Steel contour plots will now be produced based upon these settings for the effective depth. Please note adjusting these values will effect each and every As and As(d) contour plot.

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Standard 10.3.5

Bottom Steel Reinforcement Provision

Although Orion has automatically calculated the Area of Steel Requirements, this information does not relate to actual bar sizes. Therefore we are going to determine the reinforcement in the slab, based on a user defined set of parameters for the bar sizes.







Click on the Effects and select As(d)1-bot




Click on the User Defined Contours

Note: The pull down menu at the side of the User Defined Contours option allows the user to change the display settings. Shaded / Lines / Contour Values can all be switched on or off within this screen, this has no effect on the model.
Right Click anywhere in the Post Processor Window and select Contour Settings




Ensure the Number of Contours is set to 3




If the Re-Interpolate Contour values? Box appears click Yes




Make sure in the Legend box the Both option is selected. (This will display both the Bar Sizes and the Area of Steel)

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Standard The Min and Max values cannot be altered but the Contours in-between can be used based on actual bar sizes and spacing’s.

10.3.6

Creating the User Defined Contours (bottom steel)




Left Click on the first contour value




Left Click on the Steel Bar 1 and select Diameter H10 @ 250mm spacing




Click the Update button and the left hand menu contour values will show H10-250

Left Click second contour




value







Left Click on the Steel Bar 1 and select Diameter H10 @ 250 spacing




Left Click on Steel Bar 2 and select Diameter H16 @ 250 spacing. This contour value is greater than the Max 1024 mm2/m reported

Click the Update button

Note: The second contour will be based upon alternate H10 and H16 diameter bars @ 125mm spacing’s. Page 159

Standard

Note: The blue areas in the contour plot denote where H10 @ 250mm is sufficient. The green area of the contour plot is where H10@250 plus H16 @ 250mm is required. IMPORTANT All contour plots are based upon exact values, therefore these plots DO NOT include for Anchorage Lengths

10.3.7

Creating the User Defined Contours (top steel)




Select As(d)1-top plot from the Effects




Right Click to enter the Contour Settings once again




Ensure the Contours = 3 and the Legend is set to Both




Set the first contour to be H10 @ 250mm




Set the second contour to be H10 @ 250 plus H20 @ 250mm




Click the Update button after completing the settings for each contour




Click OK

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Standard Contour Settings

Your As(d)1-top plot should look as follows:-

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Standard 10.4

Exporting and Displaying Contours

Once the contours have been established in the Finite Element Post Processor, they can then be exported to the main model and AutoCAD for detailing purposes.


Ensure you still have selected As(d)1-top




Left Click on the Export Contours (shown adjacent)

This will then enable the selected contour to be exported into the Main Modelling area of the program. This would have to be done for all four contours, top and bottom in direction 1 and direction 2.
Left click on the Close window (X) to exit from this window and back into the main

model
On the Transfer Options window select Close. If any strips had been cut in the

Model this window allows transfer of this information from the FE analysis.




Left Click Close




Left Click on the Layer Control icon




Switch on the Layer Contours Asd1-Top




Click OK

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Standard


If the contours are not displayed Left Click on the Regen icon

The graphical display should now look as shown below, with the contours for As(d)1-top exported.

10.5

Exporting to DXF (for information) This drawing can now be exported as a DXF into an AutoCAD environment. To do this Left Click on the DXF icon and your drawing will be created.

All the layers will be automatically identified and transferred into AutoCAD, based upon your Layer Control settings. Any drawings created using this option will be stored in the [Default] directory for the current job (unless changed by the user) – C:\OrData15\Training_Course_Model_1a\...........DXF

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Standard 10.6

Designing the Columns/Walls

For completeness this section shows how the columns can be designed using the Finite Element gravity loads, instead of those from the Building Analysis. Note: For Flat Slab Models the column design MUST be based upon MERGED Column Forces from the FE model. Otherwise the design of the columns will be incorrect.




Click Run > Column Section Design




Click File > Column Design (Batch Mode)




Click Re-Select All Steel Bars and Calculate

New bars will then be selected based upon the Column Design Settings applied in this mornings training session, as shown below:-

All the columns have now been designed using the Finite Element Analysis Results for the Gravity Loads (G and Q), and the Building Analysis Results for the Lateral Loads (Fx and Fy).

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Appendix A : Wind Load Specifying Wind Combinations


To run the following example, please open model ‘Training_Model_1’

In order to add wind loads to the model, you should ensure that you have specified a load combination set in the Project Parameters that contains wind load vectors. For example LC14 shown below.

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Standard Applying a Single Wind Load to Each Floor

By clicking on each of the storey labels in the upper table, the Wx and Wy values for each storey can be entered in the lower table. The wind loading is entered as a single point load on each storey. The location of the load is specified by entering its X and Y co-ordinates. These are measured from (0,0) - NOT from the bottom left of the model. Note: The Notional Horizontal Loads are applied at the centre of mass of the floor, whereas the Wind Loads should be applied at the centre of the building elevation. Thus a hand calc may be necessary to determine the co-ordinates to the Wind Load location.

Wx

Fx

CG

Fy Floor Plan

X

Wy

0,0

X

The load is transferred to the columns and walls via diaphragm action within the floor. The diaphragm model is defined on the Model Options tab of the Analysis form.

It is up to the Engineer to work out the

Page 167

Standard coordinates and the wind loading to be applied. However we are given the coordinates of the centre of gravity. We can make use of these numbers to work out the coordinates to the centre of the elevation.




Use the dimension tool to show the distance to the centre of gravity and the length of the elevation.

In direction one. Centre of elevation is 19800 mm / 2 = 9900 mm Distance of the centre of elevation from the centre of mass is

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Standard 9900 mm – 8940 mm = 960 mm X coordinate is 12.940 m + 0.960 m = 13.900 m For simplicity assuming 1.0 kN/m2 wind loading The loading in the Y direction Wy = 19.8 m × 4m × 1.0 kN/m2 = 79.2 kN In direction two. Centre of elevation is 27219 mm / 2 = 13610 mm Distance of the centre of elevation from the centre of mass is 13610 mm – 12418 mm = 1192 mm Y coordinate is 15.418 m + 1.192 m = 16.610 m For simplicity assuming 1.0 kN/m2 wind loading The loading in the X direction Wx = 27.219 m × 4.0m × 1.0 kN/m2 = 108.9 kN




Enter Wx, Wy loads and co-ordinates for the storey.

Note: In practice the loadings and coordinates may change due to variations in floor layout and storey heights. For this example we will assume they are all the same.


Enter loads for the other storeys in a similar manner, and then click OK.




Return to Analysis, check the Building Analysis box and then click on Start.

The building should now be analysed for the wind load combinations in addition to the other combinations.


Click on the Post-analysis page and press the Model and Analysis Results Display button.




Using the settings and Filters you can select a wind case and view the results from that case. Viewing the deformations clearly shows the twisting effect caused by the offset of the coordinates

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Standard

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Standard Applying Wind Loads directly to Columns & Walls As an alternative to applying a single point load to the floor, the wind loads can be applied directly to the tops of the columns & walls.


Select a column and right click. From the menu choose Define Column Nodal Load.

The load can either be applied to the selected column, all columns/walls in the current storey or every column/wall in the model.


Choose Apply to Selected Column.




Select the required Wind Load Case and enter the load values to be applied. Note that the loads are applied using the global co-ordinate system.

You can enter multiple loads and moments under every available load case at the same time.


Once you have entered all values, click OK for them to be applied to the selected members

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Appendix B: Beam Design Settings and Detailing Beam Design Settings Prior to performing the design it is recommended that you take time to consider the various settings and parameters that can be used to control it. Judicious use of these settings can have a big impact on the economy and practicality of the resulting design.


From the Main Menu select Settings/Beam Design Settings/Storey Beam Settings.

A brief overview of the options in general and then more specifically the reinforcement pattern options, is provided in the next few pages.

The Design Tab

These settings are generally self evident, they will tend to have a slight influence on the values of As required that emerge from the design. For example the options to design for the shear at the column face and to use the rectangular section (rather than the flanged section) when the flange is in compression will result in slightly more conservative steel area requirements.

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Again, these settings are generally self evident, they set limits on the ranges and spacing of bars which are considered when bars are being selected to provide reinforcement which at least meets the minimum requirements determined during design.

The Bar Selection Tab

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In this tab we start to apply more specific preferences which will affect the way in which bars are selected to meet the As requirements determined in design. Standard Pattern 2 is currently the most commonly used option. Many of the other options under this tab and also under the curtailments tab are more “tuned” to standard pattern 2. Note that on the Method sub-tab the option maximise bar spacing is the default. The option to minimise bar sizes is not often used since this results in lots of small bars being used at close centres rather than a few larger bars at wider spacing.

The Curtailment Tab

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In this tab we apply preferences as to how the reinforcement is curtailed. Although this is not under the “detailing” tab, these sorts of preferences are more traditionally applied by the detailer than the designer.

The Detailing Tab

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In this tab all the preferences relate to detailing presentation options, i.e. changes here only relate to presentation and not to the reinforcement selection.

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Settings in this tab control the layering, line types etc to be used in the DXF file, which can be loaded into most general drafting packages.


If you have made any changes to the Settings and Parameters select Save to update them and return to the Graphic Editor.

Manually Creation of Drawing Sheets


From the Menu select Sheet/Sheet Layout

To bring the beams on a particular axis onto the drawing sheet, perform the following steps.


Position the cursor on the beam axis in the Axis column




then left click and hold on the axis name and then drag the beam onto the sheet




Position the beam where it is to be placed then release the left mouse button.




To manipulate the beam position click and drag the beam around the sheet




To sort according to the storeys, Select Settings and then select Storey.

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Standard Repeat this process for some more of the axes so your screen looks similar to below.

Now insert the reinforcement quantity table for these beams on Sheet 1


Select the Schedule button so the following dialog box appears.




Now select OK

The Schedule is now placed at the bottom right of the Sheet 1.


Save this sheet 1 layout by selecting Save.

Now create a new sheet which will be number 2


Select the New Button next to the Sheet No. Box so the following appears with a no. 2




Click OK

A new blank sheet appears on which more beams can be placed.


Repeat what we have done so far for Sheet 1 by selecting some more beams.

Note: You can’t select any of the beams which are on Sheet 1 or those not previously designed.


Choose Save and then Exit to get back to the Beam Section Design and Detailing window.

Now we will view the beam drawing sheets created. Go to the Menu and select Sheet/Beam Detail Drawings to get the following screen.




Highlight Sheet 1 as shown above then choose OK.

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Standard If any of the bars have been truncated you will be informed where they are and you will then need to click on OK to get to the following screen.

If necessary edits can be made to the drawing using the various commands that are available. Alternatively the drawing can be exported as a DXF file and amendments made in another cad program.

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Appendix C: Column Design Settings and Detailing Column Design Settings Prior to performing the design it is recommended that you take time to consider the various settings and parameters that can be used to control it. Judicious use of these settings can have a big impact on the economy and practicality of the resulting design.


From the Main Menu select Settings/Column Design Settings

The Design Tab

Note: Min Steel Percentage will be taken from Table 3.25 in the code, Max Col Steel Percentage will be 6.0% and Max Wall Steel Percentage will be 4% unless you overwrite the default ( 0.00 ). Plain Wall Design allows the design of walls without reinforcement where the wall is subject to compression throughout and the steel requirement is zero/negligible.

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By default Orion is set to use the BS8110 method for bi-axial design, however an alternative true biaxial approach is available. This latter method can produce some economy; however it is perhaps best though of as a means to occasionally fine tune a BS8110 design. You may decide to design using the true bi-axial method and then check the reinforcement using the BS8110 method. Clause 3.8.4.4. is the more conservative, however, if cl 3.8.4.3 is appropriate and less conservative result can be achieved.

The Steel Bars Tab

These settings are fairly self explanatory; however some consideration should be given towards the selection of appropriate lateral steel.

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Standard Details of the ‘Steel Bar Selection Method’ are displayed in the blue text below. The option to maximise bar spacing is the default. This option reduces the congestion compared to the option to minimise bar sizes.

Note: Long Walls are defined as those which have a Length / Thickness Ratio greater than 6, where a Short Wall would be used for a Length / Thickness Ratio greater than 4. If the area of main steel is less than 2% tie bars will be automatically omitted form the design.

The Lateral Steel Types can be set by clicking the Pick Buttons.

The different Column Lateral Steel options are shown to the left. Clause 3.12.7.2. specifies requirements to contain compression reinforcement by the introduction of links and/or tie bars. Using the With Tie Bars 2 option extra ties are added automatically to ensure this clause is satisfied. The Single Link option or any of the other options should be regarded as manual over-rides: the user takes responsibility for adding extra bars to satisfy cl 3.12.7.2.

There are 5 choices available for Short and Long Walls. The Shear Wall option (without End Zones) is more efficient at lower loading levels as minimum steel requirements start to dominate. The Shear Wall with End Zones option would generally not need to be used. It might however become more efficient when the walls are resisting significant in-plane moments. The Single Layer Wall can be selected for walls up to the thickness specified in the

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The settings on this tab are fairly self explanatory. For example the max bar spacing has been set to 210mm.

Note: Concrete cover 0.00 mm means the amount of cover will be taken from the code. If a non zero value is entered, this will be used instead.

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The ‘Mesh Steel’ tab allows the user to use Mesh for the design of the walls rather than loose bars. The mesh sizes used will be based on the settings from the Building Analysis Form/Material Properties.

The Detail Drawings Tab


Now click on the Details Tab and set the parameters to be as shown below.

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In this tab all the preferences relate to detailing presentation options, i.e. changes here only relate to presentation and not to the reinforcement selection.




Click on OK to save the design parameters for the columns and walls.

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From the File menu in the Column Reinforcement Design window choose Steel Optimization.




Select Column Line E-2 (1C9) as shown. It can be seen that three different bar arrangements are used up the height of this column.




Change all the bars at Storeys 3 to H20




Click on Save Axis then Close. The Utilization ratio for the modified columns are recalculated.

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Standard To Rationalise the Steel Bars in Multiple Columns To rationalise the bars selected from storey to storey for multiple columns, the Copy and Paste commands are used.


From the Column Reinforcement Design window highlight column 1C9.




Click on the Copy Steel Bars to Clipboard icon

The steel bar pattern for 1C9 is copied to the clipboard. All columns with the same b1 and b2 dimensions are marked “=” indicating that they are suitable for pasting this bar pattern to. The user can then either paste to individual marked columns using the Paste Steel Bars from Clipboard icon, or paste to all marked columns using Paste Steel Bars from Clipboard to All Similar Columns.


Click on the Paste Steel Bars to All Similar Columns icon

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Note: It is possible to paste a steel bar pattern that is insufficient. If you do this, the Design status will indicate fail for those columns as shown above. These could be re-designed interactively.

Creating the Column Detail Drawings


Left click and highlight the column you wish to produce a ‘Detail Drawing’ for:




From within the Column Reinforcement Design window select the Column Detail Drawings icon

The Column Axes List option will create a drawing of a single column by clicking on the Draw icon. If multiple columns are required on the same drawing sheet, the Sheet List option should be used as follows.


Click on the Sheet List option and then click on the Sheet Layout icon.

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Change the Sheet size to A1 and then bring the column details on to the drawing by clicking and dragging the column references from the table on the right into the drawing sheet area.




Click on Save to save the above layout as sheet 1. Additional sheets could then be created as necessary by clicking on the New button. When completed click on Exit

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To see the resulting sheet 1 click on the Draw icon.

Column Detail Drawing This drawing can be edited and plotted directly from here. Alternatively it can be exported by clicking on the DXF Export icon and then opened and edited further in AutoCAD.

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Appendix D : Foundation Design Introduction This chapter covers the following: •

Design of a Pad Footing

•

Design of a Strip Footing

•

Design of a Raft

Foundation Design Settings The Allowable Stress of Soil and the Coefficient of Subgrade Reaction are set in the Building Parameters – General tab.

Some further more detailed preferences are set in the Graphical Editor Settings – Foundations tab.

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Standard Choice of Loading Method If you have already modelled and analysed the building above the foundation in Orion, the loads can be transferred directly to it. Alternatively if you only want to perform the foundation design without modelling the structure above then the load can be input manually, Assuming you have already analysed the structure above the foundation, you have the option to either transfer the loads resulting from the Building Analysis, or (assuming you have performed a gravity load chasedown) the loads can be based on the FE Analysis results. To design the foundations using FE results, proceed as follows:


Select FE Floor Analysis from the Run menu in the Main Menu bar.




Select the Analysis Post-processing and Reports tab




Check the box Merge Column Results with Building Analysis Results.




Close the FE Analysis Form.

Note: To design the foundations using Building Analysis results, leave the box unchecked.

Pad Footing Design All the foundation design features are only available when Storey ST00 is active.


Select storey ST00 from the structure tree.




Select columns 1C2 and 1C3 and the right click and select Insert Pad Base as shown




Click OK to create a Typical Footing for both columns

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The footing data should be displayed as shown below.




Increase the footing depth to 600mm and change the bar sizes to T20 then click on the Analysis button.

A rectangular footing has been designed for the worst loads from both columns.

Note: The ‘linked circles’ icon in the middle of the screen indicates that if the Lx dimension is increased the Ly dimension will be automatically recalculated to suit. The circles can be unlinked by clicking on the icon. In this case, if the Lx dimension is increased the Ly dimension will remain unchanged.

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Check the ‘Square Footing’ box to have the footing recalculated.




If desired the bar spacing’s in the XX or YY directions can be amended at this point.




Click on Close and then click on OK to exit from the Pad Base Properties dialog.

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Standard The pad bases are then inserted under the selected columns as shown.

Pad Footing Details To obtain the detail drawings it is necessary to click on the Foundation Details icon located at the bottom of the structure tree as shown




Click on the New Detail Sheet icon.




Choose an A3 page and then click and drag the F2 footing out of the table and on to the drawing sheet.




Click with the left mouse button as necessary to reposition the footing so that it fits within the page border and then add a steel quantity table

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To return to the Graphic Editor, click on the Form Plan icon at the base of the structure tree.

Strip Footing Design The Strip Footing is a ‘combined footing’ and can be used in cases where beams connect the columns and/or walls. In cases where there are no beams between the vertical members, it can still be used but fictitious beams have to be added first which are of the same depth as the footing. The latter option will be demonstrated. Note: This section of the training manual should only be considered as a brief introduction to the Strip Footing capabilities of Orion. This subject is much more comprehensively documented in the Engineer’s Handbook. When designing a strip footing under a continuous wall in which no bending takes place along the major direction of the wall, the pad footing option can be used. Select the wall, and right click to insert a pad footing.


Create a 600 wide by 800 deep beam between columns C1 and C5, then another between C5 and C8 and a third between C8 and C12

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Select all three newly added beams and then right click and select Insert Strip Footing.




Checking the Design Envelope box will design the footing for all load combinations.

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Select T20 steel diameter and increase the footing depth to 800mm, then click on Design.

The program calculates a required Footing Width and displays a results report.




Close the report then round the width up to 2900mm and click on Design once more.

The results report is recreated based on the new width.


Click on the Diagrams tab.

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Click OK to exit, and then OK once more to return to the Graphic Editor.

Designing the Foundation Beam The foundation beam is designed in two stages:


Select Beam Section Design and Detailing/Create Update Footing Beam Records from the Run menu in the Main Menu bar.




Next, select Beam Section Design and Detailing/Foundation Beams from the Run menu.

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The beam section design dialog is displayed as below.

From this point the beam design procedure is carried out in a similar manner to the design of superstructure beams.

Raft Foundation Design Note: As there are no beams, the slab insertion method should be set to Axis Region. To get correct transfer of the column and wall loads into the raft, each column\wall needs to lie on a slab edge or corner. The raft foundation is created as a slab and then analysed using FE.


Create a 600 deep slab inside the lift core as shown below.

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Create 1m wide cantilever slabs around the edge of the core.




From the Run menu choose FE Raft Foundation Analysis

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Click on Mesh Generation and then on the icon to generate the mesh, as shown below




Exit from the mesh generator and continue with the analysis.




Select the Analysis Post Processor




Display Contour diagrams for the various effects.

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Exit from the Post Processor and then in the graphic editor try increasing the raft size.

Once a satisfactory size has been obtained, reinforcement can be placed in the raft in the same way as was done for the other FE slabs in the building.

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Appendix E : Load Combinations and the Loading Generator Typical load combinations can be selected for analysis using the Load Combination field, accessed under the Building Analysis/Pre-Analysis tab. Several pre-defined loading combinations will be available and can be accessed using the Select button. Alternatively, if you want edit an existing, or define a completely new load combination set, click the Edit button. This will take you into the Load Combination Editor shown below.

The Loading Generator Clicking the Loading Generator button provides a quick means of defining multiple load combinations.

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Standard Define Dead (G) and Define Live (Q) Loads Ticking these two boxes creates a combination of all spans fully loaded as shown:

Define Pattern Loads Ticking this box enables load patterning. The number of patterns created will depend on the selections made in Load Templates

The four check boxes at the top of the Load Templates enable the creation of basic patterns which are referred to as P1, P2, P3 and P4. Pattern P1 applies ‘adverse’ load to the first span, ‘beneficial’ load to the second span and so on. Hence making the selections shown above would result in the following combinations being created:

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Standard In the above table, G+QP1*F consists of: Dead load, G, (factored by 1.4) applied to all spans. Live load Q (factored by 1.6) applied as per pattern P1. In other words, only odd numbered spans would have any live load applied. G+QP2*F is similar, dead load (factored by 1.4) applied to all spans, but only even numbered spans have any live load applied. The following table illustrates the basic load patterns for live load:

QP1

QP2

QP3

QP4

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Direction 1 QP11

Direction 2 QP12

QP22 QP21

QP31

QP41

QP32

QP42

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Standard Apply BS8110 / CP65 Pattern Loading Ticking this box enables the dead load to be patterned in addition to the live load, as per Table 2.1 of BS8110 / CP65. Note that the effective ‘adverse’ and ‘beneficial’ load factors for dead load are 1.4 and 1.0 respectively.

Lateral Loads Notional, Wind and Soil Pressure load combinations can be generated automatically.

Notional Load Ticking this box creates four additional load combinations of gravity and notional horizontal load as shown below. In each case the notional load is applied at the centre of gravity of each floor.

Note that where the load factors are negative in the above table, this indicates the load is applied in the reverse direction. Ticking the box to ‘Apply Eccentricity’ doubles the number of notional horizontal loads. Instead of Fx and Fy, each being applied at the centre of gravity, there are now two notional horizontal loads in each direction.

Fx+ is the calculated notional horizontal load, applied in the x direction but offset from the centre of gravity by a set distance in the positive y direction. Fx- is the calculated notional horizontal load, applied in the x direction but offset from the centre of gravity by a set distance in the negative y direction.

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Standard Fy+ is the calculated notional horizontal load, applied in the y direction but offset from the centre of gravity by a set distance in the positive x direction. Fx- is the calculated notional horizontal load, applied in the y direction but offset from the centre of gravity by a set distance in the negative x direction.

Wind Load Ticking this box creates four additional load combinations of gravity and horizontal wind load as shown below. The point of application and the magnitude of the wind load at each storey are input by the user via the Storey Loads Editor accessed via Building Analysis. Refer to Appendix E for details.

Soil Pressure Load Ticking this box creates additional load combinations of gravity and soil pressure load as shown below. The point of application and the magnitude of the soil pressure load are input by the user via the Storey Loads Editor accessed via Building Analysis.

Saving a New Load Combination Set When you use the Loading Generator to create a new set of combinations it generates a set name automatically. You can use this name or rename the set from the file menu as shown.

.

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Appendix F : Report Manager Concrete and Form Estimation Reports Throughout the training course it has been possible to create individual reports at the various different stages. EG: slab design; building analysis; column design; beam design etc. There are a couple of additional reports that have not been created yet. These will be created here.


From the File menu choose Quantity Extraction Tables




Choose which tables you want to see, and in what format, then click the Create Report button




In the Orion report, click on the Save Report Button then Close and return to the Graphic Editor.




Repeat the process to create a Form Quantity Estimation report.

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From the File menu choose Report Manager.




Use the arrows to select those reports that are to be printed as shown.

If connected to a printer the combined report could then be produced.

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Appendix G : Polyline Column Editor Creating an L-shaped column.


Ensure the correct column properties are loaded (it should be labelled 1C1 – 600*300mm column) and then right click once more and choose Polyline Column Editor from the menu. The Polyline Column Editor shown below allows any shape of column to be created.

The sections shown to the right can be quickly created using the Standard Column Section icon, however in this example the column section will be created manually.

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Right mouse click on vertex 3 and pick Edit Vertex Information




Change d(next) to 550 and click Update. This sets the distance between vertices 3 and 4 to 550mm as shown.




Click Zoom Extents.




Left click on the line between vertices 2 and 3 to create a new vertex as shown.

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Right mouse click on the new vertex 3 and pick Edit Vertex Information. Change Angle(next) to 180 and d(next) to 300 and click Update as shown.




Left click on the line between vertices 2 and 3 to create a new vertex as shown.




Right mouse click on the new vertex 3 and pick Edit Vertex Information. Change Angle(next) to 90 and d(next) to 250 and click Update as shown.

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Click Cancel.

You should now have an L-shaped column of size 300x550/300x600 as shown below.

The origin point shown inside the column indicates where it will be placed relative to the grid line intersection. Clicking the Settings button allows you to change the origin position if required.




Click OK to exit from the Polyline Column Editor and save the new shape.

The column at Grid B/1 will be transformed to the L-shaped column as shown.

Select Zoom Limits

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Appendix H : Slab Design using FE Analysis Introduction For beam and slab models, as an alternative to the moment coefficient method of slab design, slabs can be designed based on the results obtained from a Finite Element Analysis (FE) of a floor instead. This is very useful to cater for those slabs that are not suitable for design by the moment coefficient method. Typical examples being irregular shaped slabs, slabs with voids or slabs with additional line or point loads applied. Note: The slab design based on FE strips which is discussed in this chapter can only be performed if a set of FE results are available for the floor in question. We will design St04.

Creating FE Slab Strips In order to design the slabs using FE, it is necessary to create FE Slab reinforcement strips.


First ensure St04 is selected

Note: FE slab strips can be created before or after the FE Analysis. To specify a Finite Element Slab Strip:


First, click on the Slab Strip icon to display the Slab Strip Properties.




Ensure the label in the Slab Strip box is X1.




Ensure the box Finite Elm. Strip is checked.




Indicate a Bob at both the start and end of the strip.




Click on the FE tab




Choose Span Strip.

To position the strip:


Draw in the strip across the slabs between Grids B-C/1-6.




Draw a second FE strip X2 across the slabs between Grids D-E/1-5.

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Note: Additional strips can be positioned as required. An FE strip can be distinguished from a coefficient strip by the FE label that appears at the end of the strip.

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Select the FE Floor Analysis from the Run menu in the Main Menu bar.

Changing the Beam Stiffness Multiplier or Slab Stiffness Multiplier may affect the results. More information on this is provided in the Engineer’s Handbook.


Select Storey ST04




Ensure the Slab Stiffness Multiplier to 0.25




Select Floor Mesh and Analysis




Select the Generate Mesh icon

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Now choose File/Exit to get back to the Finite Element Analysis Form dialog box.




When the following screen appears, click OK

FE Analysis Post Processing


Click the Analysis Post-processing button

This takes you to the Post-Processor window with the model displayed as follows:

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Click on the Orthogonal Plan Mode button as shown:




By selecting the Show Contour icon

Displacement contours.

various effects can be displayed.

Moment Mx contours.

By manipulating the loading and effect drop-downs various other results can be viewed.


By selecting the Show Contour icon off.

once again the contours can be switched back

The results for the existing FE strips can be displayed using the Select Strip drop down.


Select the strip X2

The Moment diagram for strip X2 and the G+Q*F loading should appear as below.

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Note There are options to plot either Moment or Design Moment. The latter incorporates the effect of additional Wood-Armer moments in the slab. In this particular example because the slab panels are all quite close to being rectangular there is not much difference between the two. In some models (where the slab arrangement is more irregular) the Wood-Armer effect can become significant.

Note The diagram is plotted using values calculated for the number of longitudinal points along the length of the strip. The tabulated values shown below the diagram are obtained by taking the maximum nodal results in each zone of each slab. The zones are colour coded and can be seen on the screen behind the slab strip moment diagram, as shown below. The nodes are coloured green in the support zone and orange in the span zone. The tabulated values are used for the reinforcement strip design - not the values along the strip itself.




Exit to return to the Floor Analysis Post-Processor window and choose File/Exit once more.

You will get the following dialog displayed.

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Ensure both boxes above are checked, and then select OK. This will transfer the FE slab strip results taking into account the additional Wood-Armer moments. Exit one more time to return to the Graphical Editor.

Updating the FE Strips with Reinforcement To display the reinforcement designed using the FE method:


Select and Load Properties of the FE strip X1 by right clicking




Choose Update

This should then display the steel bars.


Repeat this process for strip X2 press OK to the message below.

So that steel bars are shown as follows:

Any failing bars can be edited in exactly the same way as for the strips cut for the Moment Co-Efficient Method.

Slab Output again can be created in the same way as the strips for the Moment Co-Efficient Method.

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Slab Reinforcement after FE Analysis

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Appendix I: Enhancing the General Arrangement Drawings Creating Dimensions Exercise Aims •

Dimensioning the Grid Spacing

•

Dimensioning the Cantilever Slab

•

Creating Slab Cross-Sections

•

Exporting Drawings from Orion to AutoCAD

Dimensioning the Grid Spacing The next task will be to add dimensions to the grids created.


Select the Dimensions icon or go to Member/Dimension.

So you should now have the Linear Dimension dialog box as shown below. The top row of icons control the direction of the dimension


select Horizontal Dimension

The next row can be used to indicate if Continuous or Automatic dims are required and also if the dim is to appear on the current storey only, or all storeys.


select Automatic Dimension

The third row is used to control the appearance of the extension lines. Usually, dimensions are inserted with scale as "1". If two different drawing scales are utilised on the same sheet (as in the column application drawings) the Dim Scale option can be very useful to dimension entities drawn to the second scale. Now we can dimension up the vertical grids. You will notice the status bar at the bottom of the screen is prompting what to do next…




Click to the left of Grid 1 and drag to beyond the right of Grid 6 and then release the left mouse button.

The status bar at the bottom of the screen then asks you to click on where you would like the dimension line to appear, as shown below.




So click just above the protruding cantilever slabs.

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Standard Then the Automatic Dimension Parameters dialog box should appear.


Ensure that the Axes and Insert Total Dimension boxes are checked as shown below.




Select OK.

So your screen should look as shown below where the total horizontal dimension will be 19800. This can be checked by zooming over the total horizontal dimension

Vertical Grids Dimensioned Repeat the process for the horizontal grids A-F.


Select the Vertical Dimension direction and keep the automatic dimension selected.




Then click and drag from below Grid intersection A/5 to above Grid intersection F/5. Release the mouse button and then click on a point to the right of Grid 6.




In the Automatic Dimension Parameters dialog ensure only Axes and Insert Total Dim is checked as shown below.

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Then select OK

Your screen should look as shown below.

Dimensioning up the Cantilever Slabs Next we will dimension up the cantilever slab at Grid F/1-2 as follows:


To dimension the width of slab select Aligned Dimension.

Note the prompt at the bottom of the screen:

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To snap to the top corner of the slab, from the Osnap Modes toolbar click on intersection icon




Then click on the top left corner of the cantilever slab.

Note the prompt at the bottom of the screen:




Once again click on the intersection icon then click on top right corner of the cantilever slab.

Note the prompt at the bottom of the screen:




Click a position above the slab where you want the dimension to appear.

So your screen should look as follows:




Repeat the above process to dimension the length of cantilever also.

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Standard Shrinking Axes and Setting Unused Axes to Ghost To make drawings clearer and also to reduce modelling complications, a useful feature is the ability to shrink axes. This reduces the axis lengths so that they don’t extend beyond where needed.


Right mouse click on Axes in the Structure Tree to display the menu shown.




Click on Shrink Axes Automatically.




Click on OK and the axes should be cut back as follows.

Another feature on the same menu, which can make drawings clearer, is the option to set unused axes as ghost. This will identify any axes that are not being used on a particular storey and place them into a ghost layer. This layer can then be switched off. This feature is particularly useful where the floor layouts change from one storey to the next. In the training model this is not the case. So it won’t be used.

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Select the Section icon or

Member/Section.

Then proceed as follows:


Position the cursor to the left of Grid 1 between Grid E-F above the slab opening




Press the CTRL key and click then drag the mouse so that it extends past the cantilever slab at Grid 5.




If necessary, select Zoom Limits then click above the top of the vertical grids to insert the Horizontal Cross-Section (A-A)

Your screen should look as follows.

To get the reinforcement shown in the section:


Click on the Options tab of the Section Properties dialog and check the box Show Steel Bars then click on Update.

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Now draw a vertical section (Label it as B) between Grid 2-3/A-F.


Position the cursor to the left of Grid A, press CTRL key and click then drag the mouse so that it extends past the cantilever slab at Grid F.

You should now have 2 cross sections on your screen as shown below.

So in Section B-B you can see the void for the lift opening. The amount the walls (or columns) project above/below the section are controlled using the Upper Col and Lower Col Len boxes.

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Standard

Appendix J : Orion Data File Structure and Project Settings Orion arranges the various files of a project automatically and stores them in folders with the same name as the given project code. Orion creates a folder for each project and saves all project files in this folder. In other words, all the files for a given project will be located in the same folder. These folders will be named as the Project Code specified by the user for each project. You are not permitted to include spaces in the Project Code. Project folders are created under a parent folder called the "Orion Data Directory". There can be more than one data folder for grouping the different projects. You can use spaces in the “Orion Data Directories" however the program will prevent you from using them in the “Project Directory”.

You can change the current Orion Data Folder by the "Data Directory" button on the "Project Manager" form. The Setup procedure creates a subfolder, "TMP", under the Orion Data Directory for the temporary files created during project modelling analysis. "TMP" folder can be relocated or renamed but it shouldn't be removed. You can use the "Scratch Directory" button on the "Project Manager" to relocate the temporary files' folder. If you press the "OK" button to close the "Project Manager" the selected project will be loaded to the Graphical Editor and the parameters will be saved in a file named as the .pbp. For example, project parameters file created for the ABC1 project will be named as "ABC1.PBP" and will be stored in [Orion Data Folder]\ABC1\ABC1.PBP" folder.

Page 236

Standard Project Settings There are various project settings that can be modified to suit customer preference. Once set these will be saved with the project. A new project will normally adopt the project settings of the last project that was opened. An existing project will retain the project settings it had when it was last saved. If you have an existing project with settings modified to your preference and you would like to apply those preferences to a new project, simply ensure the existing project was the last project opened before starting the new project. To revert to ‘factory settings’ for member labelling styles, fonts and colours etc. you can check the box that appears on the Open Project dialog and shown below. Typically you would never need to check this box, as doing so will mean that your customer specific settings for these will not be applied.

Page 237

15.1

Day Two – Advanced Training Course

January 2009

Advanced

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General:

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Proprietary Rights Computer Services Consultants (UK) Limited, hereinafter referred to as the OWNER, retains all proprietary rights with respect to this program package, consisting of all handbooks, drills, programs recorded on CD and all related materials. This program package has been provided pursuant to an agreement containing restrictions on its use. This publication is also protected by copyright law. No part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means, electronic, mechanical, magnetic, manual or otherwise, or disclosed to third parties without the express written permission of the OWNER. This confidentiality of the proprietary information and trade secrets of the OWNER shall be construed in accordance with and enforced under the laws of the United Kingdom. ORION™ is a registered trademark of CSC (UK) Ltd. The CSC Logo is a trademark of CSC (UK) Ltd. All other trademarks acknowledged.

i

Advanced

ii

Advanced CONTENTS 1

Yield Line and FE Load Decomposition

2

1.1 “FE” Method for Slab Load Decomposition Design of an Irregular Flat Slab

5 7 13

2.1 Introduction 2.2 Material Properties 2.3 Building Analysis to Generate Lateral Design Forces 2.4 Meshing 2.5 Batch FE Chasedown Analysis 2.6 Verify the Results 2.7 Finite Element Analysis Form – Post Processing 2.8 Bottom Steel Reinforcement Provision 2.9 Reinforcement which is Not in the Global Axes 2.10 Column Design 3 Punching Shear Checks

13 14 16 18 20 22 23 24 36 39 41

3.1 Introduction 3.2 Column Drops 3.3 Performing Individual Punching Shear Checks 3.4 Checking Multiple Columns 4 Advanced Modelling

41 43 43 51 53

4.1 Introduction 4.2 Creating Curved Grid Lines and Beams 4.3 Inserting a Sloping Column 4.4 Creating Planes 4.5 Modelling Pile Caps 4.6 Hint and Tips for Modelling Inclined Members 5 Transfer Structures (Beams and Walls)

53 55 56 59 62 64 65

5.1 Introduction 5.2 Transfer Beams – General Method 5.3 Discussion of Frame Analysis Results 5.4 Gravity Loads (FE Meshed Wall Modelling) 5.5 Transfer Walls 5.6 Transfer Beams – FE Method, Option 1 5.7 Transfer Beams – FE Method, Option 2 (for information) 6 Transfer Slabs

65 65 68 73 75 80 89 93

6.1 Modelling and Initial Analysis Diaphragm Modelling

93 103

7.1 Introduction 7.2 Diaphragm Modelling Options: 8 Duplicate Floors

103 103 110

7

9

8.1 FE Chase Down with Duplicate Floors Importing a .DXF Drawing

9.1 Introduction 10 Training Presntation Slides

110 112 112 120

iii

Advanced

iv

Advanced

1 Yield Line and FE Load Decomposition




Open the model shown above Load_Decomposition_Worked_Example_R15.

This is a simple single storey 6m by 4m slab, supported by four beams and columns. Eccentric concentrated point loads are applied and a large void also has been defined as follows: Eccentric Loads e1 = 1m, e2 = 0.5m e1 = 5m, e2 = 0.5m

G = 100kN, Q = 100kN G = 100kN, Q = 100kN

Void e1 = 4m, e2 = 3m, b1 = 1.5m, b2 = 0.5m The Traditional (Yield Line – shown by the dotted Red Lines on the slab) method of load transfer would ignore the hole, and it would average out the point loads by calculating an equivalent UDL to apply over the whole area of the slab. Although the load is not lost, its effect is independent of its proximity to any of the surrounding beams. For example: G total point loads =

100 + 100 = 200kN

Therefore this will be applied over the whole slab area when being considered as part of the Yield Line Analysis = 200 / (6*4) = 8.333 kN/m2 This is all reasonably apparent when you examine the beam loads.

Page 5

Advanced


Right Click on Beam 1B1 and select ‘Edit Member Loads’

The loading on beam 1B1 is a simple trapezoidal profile where the peak UDL is adjusted to account for the point loads. Based on this method, beam 1B2 sees an identical loading profile. When you run a building analysis, a completely symmetrical set of column loads is determined as shown below.

The example shown above has the View Options > Columns and Walls, set to display the Axial Loads for the Dead (G) and Imposed (Q) loadcases.

Page 6

Advanced 1.1

“FE” Method for Slab Load Decomposition

By using the optional Finite Elements Model, the point loads will be much more accurately distributed. The slab load will also be more accurately distributed, including the deductions and effects associated with the void. The procedure for generating optional beam loads based on an FE model is as follows:


Select the ‘FE Floor Analysis for Beam Loads’ command from the Run menu as shown below, or by using the icon at the top of the screen.

Then click on the button “Determine Loads Transferred from Slabs”, this will open up an FE modelling window.

It is important to note the advice on mesh density that is given in the above dialogue box, as covered on Day 1 of your training. A number of plates are suggested by default. Click on the “Generate Mesh” icon and the slab is meshed automatically.

Page 7

Advanced

In this case using 100 plates is adequate, although not well meshed around the opening this is probably sufficient in this simple example for the intended purpose.


Close this FE window and then also the Finite Element Analysis Form to return to the Graphic Editor.

Having completed the above “FE” information exists for all beams in the current floor. You can review and apply this on a beam-by-beam basis.


Select any beam and open the beam loads dialogue, then swap to the “Finite Elements” Slab Load Decomposition Method. The effect of choosing this option for beam 1B1 is shown below.

Page 8

Advanced

As expected the load intensity is peaking towards the ends where the point loads are applied, in addition you can see how the load does not peak as intensely at the right hand, this is due to the effects of the hole. To make more sweeping changes between methods:


Select any beam or beams, right click, and choose the “Slab Loads Decomposition Method”. The FE results can then be applied to selected beams, all beams in the current storey, or to the whole model:

Page 9

Advanced To complete this simple comparison we will swap to the FE method for all beams and then re-run the building analysis. On completion we can see a very different distribution of column loads.

Note: that the total IL using the Yield Line method was approximately 267.7kN. Using the “FE” method it has dropped to 265.9kN, this is slightly lower because no load is applied to the hole. Note: If you change any slab loads or beam layouts, you must remember to re-run the FE Floor Analysis for Beam Loads command before re-running the building analysis. Note: Axial load comparisons are performed at the end of each analysis. This is a comparison of applied loads vs. analysis reactions. You can also choose decomposition method on a beam-bybeam basis but this can cause the Axial Load Comparison to show discrepancies.

Page 10

Advanced

The first applied loads table shows the totals for the loads applied to each slab, beam, etc. The second applied loads table shows the loading totals after decomposition.

Page 11

Advanced

Page 12

Advanced

2 Design of an Irregular Flat Slab 2.1

Introduction

In this example a Flat Slab Model will be Analysed and Designed as shown below:-

Consider the model shown above. A core wall system is assumed to brace the structure and therefore the flat slabs and peripheral columns are to be designed for gravity loads only. Although it looks like a simple layout, it would actually be very difficult to apply the idealisation of column and middle strips and hence it becomes almost impossible to apply the code’s simplified design methods. Therefore the Orion Finite Element Analysis is going to be used to determine the Gravity Loads on the Columns and Walls.


Open the project called Irregular_Flat_Slab_R15

In order not to destroy the example for someone else you should then save the model with a new name before proceeding.

Page 13

Advanced 2.2

Material Properties

2.2.1

Long Term Elastic Modulus

In the Day 1 training session an FE load chase down was performed with a ‘Slab Stiffness Multiplier’ of 0.25. In today’s example we are going to use a slightly different technique, by applying a 0.25 reduction factor to all member types in the model. Both approaches are to allow the Engineer to view long term deflection estimates for the Flat Slabs to estimate the effects of Cracking/Shrinkage and Creep, see later presentation. By changing the Properties of ALL elements we are complying with the code ‘consistent section properties’ and the distribution of load will be unaffected. If only the ‘Slab Stiffness’ is adjusted the columns will attract more moments, perhaps greater than traditional Engineering expectation. Ensure that the concrete material properties are adjusted so that a long term E value is used; in this 2 case C40 concrete is used with E set to 7000N/mm .


Enter the Building Analysis Form and click Edit




Left Click on Slabs




Left Click on ‘Reset Grades and Classifications’




Type ‘0.25’ as the ‘Factor to be applied to the mean short term E values’




Click OK




Select C40 making sure the Modulus of Elasticity = 7000N/mm2




Tick the ‘Apply to All Member Types’




Click OK in the ‘Concrete Grade’ window




Click OK in the ‘Material’ window




All element types have now been set for a Long Term E value; this will ensure a ‘Consistent Set of Section Properties’

Note: These settings for the Material Properties apply to both the Building Analysis and the Finite Element Analysis.

Page 14

Advanced

2.2.2

Steel Properties




Using similar techniques as used to change the Concrete Grades specify Grade 500 steel with a Steel Material Factor of 1.15




Check the Bar Sizes for all Member Types are set to H10/H12/H16/H20/H25/H32

Page 15

Advanced 2.3

Building Analysis to Generate Lateral Design Forces

Remember to use the un-decomposed slab loads for the calculation of the storey weight.


Building Analysis > Analysis Form > Model Options > Settings




Run the Building Analysis by left clicking ‘Start’, making sure the Column/Wall and Beam Reinforcement Design is ‘Unticked’

Page 16

Advanced

At the end of the analysis process you should see a warning indicating load has been lost. This warning will always appear when running building Analysis for flat slabs. It indicates that an FE analysis is required for the gravity loads.

In the Building Analysis the slabs are replaced with diaphragms to decompose the lateral loads to the Columns/Walls in the structure. As no beams are present in the model there is no means of decomposing the Vertical Loads onto the Columns/Walls, therefore the FE will analyse for the Gravity Load Chase Down for the structure. Note: The lateral design forces ONLY will now have been calculated.

Page 17

Advanced 2.4

Meshing

To perform the Gravity Load Chase Down, we are going to use the Finite Element Floor Analysis.

th

At the 4 floor level use settings as shown above ‘Column/Shear Wall Model Type’ – The ‘Short Frame Model’ should be selected to allow the Columns and Walls to form part of the FE Model. This should be the chosen option to allow moments to develop between the Slabs and the Columns/Walls and will also allow the load to be transferred to the floor below. These options will be discussed in more detail during today training presentation. ‘Beam and Slab Stiffness Multipliers’ – The Slab Stiffness Multiplier (SSM) was used during the Day 1 Training Course to asses the Long Term Deflections of the slabs. These multipliers are typically left at 1.0 ‘Include Column Sections in the FE model’ – This allows the Finite Element Mesh to form around the perimeter of the columns, producing moments at the face of columns rather than the centre of the columns. This option significantly reduces the peak hogging moments over the column heads in Flat Slab Construction. ‘Include Slab Plates in FE Model’ – This option ‘must’ be selected for Flat Slab Models. For Beam and Slab models un-ticking this option would allow the Beams to be loaded as per the Building Analysis model, using the Yield Line or FE or Beam Loads. ‘Consider Beam Torsional Stiffness’ – This allows the torsional stiffness of any beam members to be considered in the design. Un-ticking this option would assume the beams to have No Torsional Capacity. ‘Include Upper Storey Column Loads’ – This option must be selected to allow the Load to be chased down through the model (even at the top storey).

Page 18

Advanced Left Click on the ‘Floor Mesh and Analysis’ button to enter the FE pre processor, using 1500 plates and a Mesh Uniformity Factor of 100%







Note: The mesh density and Mesh Uniformity Factors should be adjusted to try and achieve between 6-8 plates between the column heads.

You could adjust the mesh density from the default down to a lower setting that you think might be acceptable. However, using 1500 shells and setting the uniformity factor to 100% produces a mesh as shown below which is clearly more than adequate. This operation could be performed at each floor level by analysing and moving to the floor below until the load has been transferred to the foundation level. However using the ‘Batch FE Chasedown’ this procedure can be automated:-

Page 19

Advanced 2.5




Batch FE Chasedown Analysis

Make the settings as shown above and click OK (note how St04 is ticked denoting the analysis has already been completed)


Un-tick the ‘Pause to Check Meshing at Each Floor’ as the floor plates are all the same in today’s example there is no need to check and approve the Mesh at every floor level.

It may be that you choose to Check the Mesh at Each Floor level for the first FE run of the Load Chase Down. However after minor changes you may well un-tick this option.

Page 20

Advanced When the FE Load Chase Down is complete the Maximum Positive and Negative Displacements are shown at each floor level (excluding duplicates).




Before Exiting the ‘Finite Element Analysis Form’ tick the ‘Merge Column Results with Building Analysis Results’ and left click ‘Close’

Page 21

Advanced 2.6

Verify the Results

Return to the Building Analysis Post-Processor in order to access the Axial Load Comparison Report. This should be used to confirm that, as opposed to the Building Analysis, when running the FE Analysis none of the load is lost.

Table 1 – Undecomposed Loads

Table 4 – Finite Element Chasedown Results – Decomposed Loads




Enter the View Options and go to the Columns and Walls tab. Select Axial Loads only LC1:G, LC6:Q and Cmb1:G+Q*F Note: If you have chosen to design including Imposed Load Reduction Settings for the columns (Edit Storey), the Axial Loads G and Q are the total Unfactored Dead and Imposed Load. Any Cmb results reported graphically include the Imposed Load Reductions if applicable. Cmb1 = (1.4 * 1602.0) + (0.7 * 1.6 * 579.5) = 2891.9kN

Page 22

Advanced 2.7

Finite Element Analysis Form – Post Processing

Return to the FE Analysis Post-Processing dialog for the 4th floor. Set the Positive (sagging) Moment Factor to 1.2 before accessing the contour plots.

Why the adjustment? For Finite Element Floor Models it should be noted that they do not include for the effects of Pattern Loading. It is not feasible or logical to automate pattern loading to generate every possible worst case scenario for every conceivable irregular arrangement. If you are concerned about the effects of Pattern Loading we suggest amplifying the ‘Positive Moment Factor’ (10-20%) to allow for these effects.

Estimated factored total deflection is peaking at around 75mm along the perimeter lengths between columns (calculated on the basis of a 0.25 adjustment to the long term elastic modulus). The unfactored deflection is thus 75/1.45 = 52mm. The distance between these columns is about 11.3m therefore we should be looking to see total deflection restricted to around 11300/250 = 45mm. This suggests a thicker slab may be required for these long edges. However we will continue with the example unaltered.

Page 23

Advanced 2.8


Bottom Steel Reinforcement Provision

Before starting to review reinforcement requirements right click in the graphics area and set the effective depth information to some reasonable values.

We will start by assuming that the whole slab is to be reinforced orthogonally in the Global X and Y directions. At this point the slabs reinforcement angles have not been adjusted, so direction 1 steel is aligned with global X, which runs from left to right in the view below.

Page 24

Advanced This view (above) shows bottom steel requirements in direction 1 and as might be anticipated the peak requirements are occurring along the longest free edges. In direction 2 (below) we see a very similar 2 situation and a very similar peak requirement of just under 1400mm /m.

In practice you may want to consider the reinforcing requirements if the main steel along the angled edges is aligned to the edge. This can be done and will be shown in an extra section at the end of this example.

Note: All contours / values shown within the Finite Element Post Processor are shown in mm2/m

Page 25

Advanced We can now use the custom contours option to show where different steel reinforcement provisions would be adequate. In general the strategy would be to decide on some general lower level of reinforcement to be provided continuously throughout the slab and identify the regions where an increased provision is required.


Left Click on the User Defined Contours icon




Right Click in the Main Window, then Left Click on the Contour Settings option

Effect

- This is the brought through from the current view selected in the FE Post Processor

Loading

- The current Loadcase or Combination selected in the FE Post Processor

Legend - This allows the user to choose the information displayed on the legend within the 2 Post Processor – Contour Value only 565.5mm /m / Contour Labe only (T10 – 200) / Both Number of Contours - This allows the user to specify the number of contours to be displayed on the screen. Note. The Minimum (0.0) and Maximum (1395.5) cannot be changed. Contour Label / Contour Value / Diameter and Spacing - This area allows the user to select bar sizes and spacing’s for the creation of the contours. The labels and values are automatically created based on the selected size and spacing of the reinforcement.

Page 26

Advanced


Make the settings below and click on Update then OK to view the Reinforcement Requirements for the Bottom Steel, in Direction 1 (Global X axis in this case), including Wood and Armer Adjustments.

Page 27

Advanced 2.8.1

Creating contours (bottom steel provision)




Using the same techniques create the As(d)2-bot contours, as shown below




Create two contours H12 @ 200 and H12 @ 200 + H16 @ 200mm

We have now considered the possibility of laying in extra H16 at 200 (providing H12 and H16 alternate bars) and the view shows that this is adequate everywhere else. These requirements can be simply communicated to the detailer by exporting the above contours to the main graphical editor and then to DXF.

Note: Although only 2 reinforcement provisions have been shown in the above example, if required many more contours could be introduced to suit specific project requirements.

Page 28

Advanced 2.8.2

Creating contours (top steel provision) – As(d)1-top

As expected, a review of the top reinforcing requirements shows that in theory no steel is required over large areas of the slab and that the hogging moments intensify rapidly over the column heads and core wall. However, many (most?) engineers would tend to provide minimum reinforcement throughout the top of an irregular flat slab and so the user-defined contours below show this as the minimum level.


Create the contours shown below: H10 @ 200 and H10 @ 200 + H16 @ 200

Page 29

Advanced In this case we can see H10 at 200 will be provided everywhere (blue). Then we see large areas where H16 at 200 would need to be added leaving relatively small areas where a higher provision is necessary (green). As is covered in the training presentation, the only practical way to deal with these peak requirements is to integrate results in strips cut across the column and wall heads. In the view below a 2m wide strip is cut across the head of the most critical internal column.




Click the Strip icon within the Post Processor then type the ‘Half Band Width’ as 1.0m. This will create a strip a total of 2.0m in width. Hold down Ctrl whilst left clicking and dragging the strip extents, this will allow the strip to snap to the horizontal (0 degrees) position, see below:-

Based on the proportions and span of the slabs involved this might be considered as a reasonable strip 2 width and the average steel requirement in this width is approx 2000mm /m. However, if this steel were provided, it must be provided over at least the 2m width of the strip. Clearly this strip strays beyond the contour boundaries where a much lower steel requirement has been shown to be adequate. ‘Design Moment’ –

Allows for Wood and Armer Adjustments

‘Req. Steel Area’ –

Converts the Design Moments into area of steel in mm /m

‘Integral’ –

Takes the average vales over the width of the strip

2

Note: The blank area in the centre of the strip is due to Including the Column Heads in the Finite Element Analysis (therefore moments taken at the face of the columns). Attention should also be paid to the direction of the strips being cut in the model, strips should be cut in the same direction as the direction of

Page 30

Advanced As an alternative it is more conservative to cut a narrower strip as shown below with a ‘Half Band Width’ of 0.5m – (Strip 1).

This strip is cut just within the boundaries where the lower provision of H10@200 + H16@200 is shown 2 to be adequate. The average requirement in this narrower strip has increased to 2595mm /m. (This is now in line with the rule of thumb expectation that the peak hogging steel provision will be in the order of double the peak sagging steel provision). The same principle can be applied at the walls (Strip 2).


Click the Strip Adjacent to the wall the slab span is 9.5m and cut a strip 2.2m (1.1m Half Band Width) wide as shown below:




Make a note of the average requirements over the column head and the shear walls from the two strips




Strip 1 – Column strip – 2595mm2/m




Strip 2 – Wall Strip – 2425mm2/m

Peak requirements tend to occur around the ends/corners of walls, and a little unusually in this example the peak requirement at the wall corner is actually higher than at the column. In this area there is not

Page 31

Advanced much of a case for cutting a wider strip and determining a lower average steel requirement in the vicinity of the wall. Now we have gathered the results by using Strips and taking the average over a given width we can now add a final contour to satisfy the ‘Average Strip Result – Integral’ rather than the nodal peak moment values in areas of high hogging over the columns. 2

Hence, our final contour will be required to satisfy the Strip 1 value (maximum) of 2425mm /m. If we assume we are going to maintain the H10 steel at 200mm centres then the additional bars in these areas to satisfy the ‘average’ values will be:H10 @ 200 + H20 @ 200 H10 @ 200 + H25 @ 200


= =

2

1964 mm /m 2 2847 mm /m

>

2

2595 mm /m

Create a third and final contour for H10 @ 200 + H25 @ 200mm (the yellow areas will then show where the additional H25 bars are required).

Upon closer inspection of the contour plots you can see ‘red’ areas are shown, this is suggesting that the contours created are not adequate. This would be the case if we were considering every nodal value for the floor plate. However, as we have chosen to design these areas by using the ‘Integral’ (average) results the red areas can be ignored.

Page 32

Advanced Note: In order to achieve standardisation throughout you may then choose to provide H25 at 200 as a standard “patch” of reinforcement across all column heads. Once again this information can be communicated to the detailer byAdditional adjusting the Notes on Top Steel Provision – As(d)2-top 2.8.3 user defined contours as
Select the As(d)2-top plots from the Effects tab and a ‘Warning’ as shown below may

be displayed.

On accessing the top reinforcing contours a warning is displayed. The problem area is the top left corner of the core wall. The nodal moment here is so high that the As requirement can not be calculated for the 300 thick slab and hence it is reported as zero – Node 47 in this case.

You will notice the contour plot is distorted (blue), and reporting a nodal value of Zero. However, the slab thickness is not undersized so it should be possible to determine the steel requirement by use of integral strips.

Page 33

Advanced Since the walls are modelled as a series of nodes, undesired stress concentrations may occur at these locations, which may result in unexpectedly high support moments.

Column / Wall Node Interpretation – Include All results from all nodal points will be taken into account for the design of the slab.

Green Nodes – Included Column / Wall Node Interpretation – Ignore Shear wall end nodes will be ignored, and the results from the adjacent node will be used.

Red Nodes (end of walls and column centre nodes) – Ignored Column / Wall Node Interpretation – Interpolate The results used for the end of walls and columns are obtained by taking an average from the peak centre node and the neighbouring nodes.

Page 34

Advanced Red Nodes Ignored – Smaller green dots between nodal points used for the design of the slab.

To eliminate the distortion to the contour plot caused by the zero value, it is possible to redraw the diagram with the column/wall nodes as shown below with the values at these nodes averaged with their neighbour nodes. This may be useful when creating contours to pass to the detailer.

These contour plots could then be used to determine the steel requirements for the As(d)2-top reinforcement requirements.

Page 35

Advanced 2.9 2.9.1

Reinforcement which is Not in the Global Axes FOR INFORMATION ONLY

It was noted that for this slab some of the highest sagging moments and hence the greatest bottom steel requirements occur along the angled slab edges. This requirement was being established on the assumption that direction 1 and 2 steel will be provided in the global X and Y directions throughout. The steel requirement at this point is high in both directions. If you check you will find high design moments in both directions at these points, and if you look at the unadjusted moments you will find that Mxy is very high and that the Wood and Armer adjustment is having a big impact on the design moments for reinforcement if it is not going to be provided parallel to the free edge.

Logically you would expect that steel provided parallel to the free edge would be the most efficient solution in an area like this. There are 2 ways in which this requirement can be investigated in Orion.

Page 36

Advanced When you cut a strip at an angle as shown above you will automatically be looking at moments and hence reinforcing requirements along the cut line.

Alternatively you can define the intended reinforcing angles in any/every slab independently and view contours on that basis. In the view below, you can see how the reinforcing angle has been reset in the four panels adjacent to these edges. Note the Angle is relative to the Global co-ordinates (+ve X = 0 degrees etc.), and the angle specified (shown by the large blue arrow) is the Direction 1 axis. Hence Direction 2 will be orthogonal to Direction 1.

Page 37

Advanced After re-meshing and re-analysis, you will see contours as shown below.

The direction 1 steel area requirements are shown above appear very similar to the requirements shown earlier before this adjustment was made. The direction 2 requirements shown below are quite different. Direction 2 is perpendicular to the free edges, and as expected the reinforcement requirement becomes nominal at the edges where a peak was previously exposed.

In terms of the weight of reinforcing provided, it would be more efficient to design a perimeter ring and then place orthogonal infill steel, but this may not be the fastest/simplest or even the cheapest construction solution. Using Orion as shown above you can quite easily investigate such options and you could even create extra slabs to define a ring beam zone. As was noted in this example and in the training presentation, it is relatively easy to generate the design information (the information that can be passed to a detailer) in Orion. This example should reinforce the view that for flat slabs it may be better to restrict your use of Orion to this level of detail and then revert to traditional detailing.

Page 38

Advanced 2.10

Column Design

By following the procedures discussed in Orion Day 1 Training the columns can then be designed.


Merge the Column Results with Building Analysis Results




Run > Column Section Design




Perform Column Design (Batch Mode)

The view above shows that axial loads and moments are transferred from the FE analysis (short frame model) and that the braced columns can now be designed in Orion including for IL reduction factors if desired. Since there are no beams attached to these columns Orion assumes a small strip of slab is effective as the beam and calculates effective length factors on this basis.

Page 39

Advanced

Page 40

Advanced

3 Punching Shear Checks 3.1

Introduction

Punching Shear is often not checked until near completion of the project, and can be found to have a significant effect on the additional reinforcement required to prove thin slabs for these effects. Although many design guides will show checking the Punching Shear as the final design check we would encourage the Engineer to investigate the quantities of additional reinforcement required to satisfy Punching Shear, before committing to a slab thickness and general reinforcement provision in the flat slabs. If lots of additional reinforcement is required it may be more economic to increase the amount of reinforcement over the column heads or even thicken the slab. Orion can perform the Punching Shear Checks for all columns and walls which support slabs over. The results are reported as a series of progressive perimeters, checked in accordance with the code (BS8110:1). Currently the checking of transfer columns / walls sat on slabs is Beyond the Scope of Orion. Manual checks will have to be performed for such locations in the model. Scope of the Punching Shear Checks within Orion:-




•

Shear is checked around the perimeter of the column (max 5.00N/mm2)

•

Veff is calculated in accordance with clauses 3.7.6.2 and 3.7.6.3 of BS8110:1

•

Internal / Edge and Corner columns can be checked

•

Holes in the slabs can be accounted for in the checks

•

Drops can be introduced to resolve problem areas

•

Progressive perimeters are checked and the additional quantities of shear reinforcement is reported

Open model Punching_Shear from the Training Model Directory

Page 41

Advanced


Run the Building Analysis, making sure to untick the Column/Wall and Beam Reinforcement Design. This analysis has now produced the lateral load analysis on the model.




Run the Finite Element Floor Analysis with the settings shown below, to allow the Gravity Loads to be generated for the model. The FE Floor Analysis will generate the information to allow the punching shear forces to be developed. The FE Floor Analysis Must be completed to perform the Punching Shear Checks in the model.




Merge the Column Results with the Building Analysis Results from the Finite Element Analysis Form > Post Processing and Reports.

This will now place the Finite Element Loads on the columns for consideration in the Punching Shear Design checks.

Page 42

Advanced 3.2

Column Drops

Column Drops can be introduced into any column or wall for consideration in both the FE model and the Punching Shear Checks. Column 1C7 shows a Blue dotted perimeter, indicating a column drop has been introduced, this is done using the Column Properties > Column Drop

b1 and b2 are the length and width of the drop panel (shown by the blue box in the main window) h-Head – Depth of the drop from the top of the slab. In our example a 400mm h-Head with a 200mm Flat Slab will allow the drop to project 200mm below the soffit of the slab.

3.3


Performing Individual Punching Shear Checks

Left Click then Right Click on Column 1C6

Page 43

Advanced 3.3.1

The Punching Shear Check Window Column Punching Perimeter Options Circular Column – This allows the user to check either square or round perimeters for Circular Columns Check Column Perimeter – If this box is ticked then the 2 columns perimeter will be checked (1, and vice versa Corner columns must be checked using the far right icon.


For the Individual Column Check make the settings shown below for Column 1C6


Then Click Calculate

2

Note the Area of steel is calculated in mm /m for the punching shear checks. This is consistent with the units for the FE Post Processor

Page 45

Advanced 3.3.2

Design Results

Nd Md-1 Md-2

-

Axial Load kN Bending Moment in Columns Direction 1 kNm Bending Moment in Columns Direction 2 kNm

Vt Mt-1 Mt-1

-

Design Shear Transferred to Column kN Design Moment Transferred between Slab and Column fin Columns Direction 1 kNm Design Moment Transferred between Slab and Column fin Columns Direction 2 kNm

Check 1 – Face of the Loaded Area d thickness of the slab 200mm d-eff effective thickness of slab – 200 – 25 (cover) – (16 + 16 / 2) (ave bar dia) = 159mm Factored Storey Load = (Floor Dead * 1.4) + (Floor Live * 1.6) = 13.62kN/m

2

Clause 3.7.6.2 for Internal Column connections in Flat Slabs states:Veff = Vt (1+ 1.5Mt / Vt x) Uo The perimeter of the column Ao The area of the column 2 v = Veff / Uo * deff 429000N / (934.4 * 159)mm 2.89N/mm

2

<

5.00N/mm

2

=

2.89N/mm

2

OK

Page 46

Advanced Check 2 – 1.50d from the column face 1.5d = 1.5 * 159 = 238.5mm Length of one side of the perimeter = 2 * 1.5d + column width = Perimeter at 1.50d 4 * 774.4 Area of Perimeter @ 1.50d 774.4 * 774.4

774.4mm 3097.6mm 2 599695mm

Vt = 416 – [13.620 (Fac. St. Load) * 0.599695] = 416 - 8.168kN =

407kN

x = the length of the side of the perimeter considered parallel to the axis of bending Veff = Vt (1+ 1.5Mt / Vt x) = 421kN

dir 1 and

v = Veff / u * deff

421000 / 3097.7 * 159 409000 / 3097.7 * 159

774.4mm

409kN dir 2 2

= =

0.86N/mm 2 0.83N/mm

=

0.80N/mm

v < 1.6 vc Direction 1 (Direction 2 checks will also be performed) ∑Asv sinα > (v – vc) ud / 0.87 fyv

=

68mm

Minimum

=

453mm

Table 3.8 states vc

=

0.79 * (100As / bvd)

1/3

* (400 / d)

1/4

* (1 /

Therefore Shear Reinforcement is required

m) * (fcu / 25)

1/3

2

v > vc

Clause 3.7.7.4

0.4ud / 0.87fyv

2

2

Therefore provide the minimum. Note: This figure is the total amount of Shear Reinforcement required for this perimeter. The red dotted lines show the failing which require additional Punching Shear reinforcement. The Asv reported is the total amount of reinforcement required to the whole perimeter. Green dotted lines indicate a passing perimeter where additional Shear Reinforcement is not required. If the first perimeter is red with no further perimeters this would indicate a failure at the column face.

Page 47

Advanced


Add the slab opening as shown below

Note how the perimeter is now modified with Black dotted lines to indicate the extent of the perimeter not being considered in the punching check design. The perimeters are modified automatically based upon any holes which are modelled in the slab. If holes are known to exist but have not been modelled then the ‘periphery reduction amount’, can be used to manually modify the extent of the punching perimeter for this check.

Page 48

Advanced


For the Individual Column Check make the settings shown below for Column 1C7 Check 1 -This first check will be performed at the face of the 300*300 column, assuming the depth of slab to be the same as the drop panel.


Untick the ‘Drop Panel Perimeter

Although in this example the column perimeter check is only applicable, if the 1.5d (2.25d etc…) perimeter still falls within the drop, this will also be checked

Check 2 – The second check will be performed for the extents of the column drop panel, and its progressive perimeters.


Tick the ‘Column Drop Panel Perimeter’




Untick the ‘Check Column Perimeter’




Click ‘Calculate’

Page 49

Advanced For the Corner Columns


Left Click on the ‘Column Location’ as Corner




Set the Slab Reinforcement in the X and the Y direction to be H16’s at 200mm centres




Click Calculate to perform the check Note: All corner columns in the model could have been selected and edited in the Run > Column Punching Check window (see notes below) The same procedure would be necessary for the edge columns in the model, to ensure the correct values for the perimeters are used.

Page 50

Advanced 3.4

Checking Multiple Columns


Left Click on the Clear Selection to de-select any elements currently selected


Left Click on Run > Column Punching Check This function will allow all the punching shear checks to be performed at once for this floor plate only. If several columns had been selected only those would appear in this window

Changing the bar sizes for example of multiple checks can be done by using the ‘Columnwise Editing’ button shown above.


Left Click on the blue word ‘Diam-1’, this will highlight the column




Left Click on the ‘Columnwise Editing’ icon




Change the Bar sizes for 16mm




Click Ok, see how all the bars have now changed for H16’s

Page 51

Advanced




Change all the bar sizes to be H16 @ 200mm centres in both directions




Click Calculate

Additional Notes: Walls can also be considered for the Punching Shear Checks within Orion Slabs sat on columns can be checked, but transfer Columns/Walls sat on slabs remains Beyond the Scope of the current Orion version

Page 52

Advanced

4 Advanced Modelling 4.1

Introduction

With the release of Version 15.1 came new geometry functions to allow the user to create structures with increasingly complex geometry, a list of some of the major enhancements are as follows:•

Curved Beams (in plan)

•

Sloping Planes

•

Sloping Columns

•

Sloping Beams

•

Sloping Slabs

•

Pile Caps

This chapter covers some of the above topics in a relatively simple modelling exercise, which demonstrates the enhancements recently introduce to Orion.

Above is a screenshot from the completed model, which this exercise will focus.

Note: Please read the Hints and Tips at the end of this section, before using these options on your own models.

Page 53

Advanced


Start a new model called ‘Advanced Modelling Exercise’




Create the drawing sheet size to A2, and the Storey Height to be 3000mm




Set up the grids and the levels as shown below using the ‘Orthogonal Axis Generator’




Create the four 500*500 columns and beams as shown below




Create a 200mm slab as shown. The slab loads are to be 0.5kN/m2 for Additional Dead and 5.0kN/m2 for Imposed Load

Page 54

Advanced 4.2

Creating Curved Grid Lines and Beams

Orion can now be used to place a series of facetted grid lines in the model to form curved edges, ready for the insertion of Beams and / or slabs. This technique is also useful when creating a curved edge to a flat slab model.


Left click on the Beam icon and specify the properties for a 250*250 beam




Hold down shift, left click and drag from axis points A2 to C2, a window will then be displayed as shown below:This window allows the user to specify curved Axis and Beams Parallel Offset – This option can be used to create beams offset from the two points you have dragged between for the beam insertion. In our example today these will be left at I (start) = 0.0mm and J (end) = 0.0mm. Curved Beam Insertion – This allows the curve to be specified from the set out points shown h, c and R. Set the Chord Offset to be -2500. Note negative values reverse the curve. Tangent Segments – The grid / beams can be set out about the external face of the beams. Un-tick this option to set out the beams about the centreline. Number of Segments – This is the number of straight edges the beam will be split into for its insertion in the model, use 8 in this example.




Add another slab to this area (note how the Yield Lines have been formed around the curve to suit the number of beams)

Page 55

Advanced 4.3

Inserting a Sloping Column




Set up the column Properties as shown 250*250 column aligned central to the grid




Set Dir to 1, to make the column parallel and perpendicular to Axis B




Left click on the Pick Bottom Insertion Point icon




Left Click on the Axis Intersection B/3




Click Update

The column has now been inserted in the model with varying insertions for the top and bottom,

Page 56

Advanced Create Storey 2 (St02)


Right Click on Storeys and select Insert Storey – Click OK




Create the 250*250 columns and beams as shown below Note the two central columns are supported by the beams on Storey St01 below.





Create the Offset Beams running horizontally (in plan) at the mid-span of the two bays. This is done by holding Shift (drag from A/1 to A/2)whilst creating a beam to open the ‘Beam Insertion and Offset Options’

Tick the Parallel Offset option and insert an Offset Distance of 2000mm. Do this in both bays, as shown on the following page.

Page 57

Advanced


Insert the 150mm deep slabs with Additional Dead Loads of 0.5kN/m2 and Imposed Loads 1.5kN/m2




On these slabs tick the ‘Slab Does Not Contribute to Floor Diaphragm’

Page 58

Advanced 4.4

Creating Planes

Creating planes allows the modelling of sloping beams and slabs within Orion. Planes must be created before sloping members can be added.


Left click the ‘Plane’ icon




Holding Down ‘Ctrl’ left click on slab 2S2 and 2S3, you should see the red box increase in size as additional slab panels are selected. Planes are denoted in the model with a reference P1 etc…….




Repeat this same process with slab panels ‘2S4 and 2S5’




For Plane 1 (P1), left click and select Properties, and edit points 1 and 2 as shown, to be 2000mm




Adopt the same principle for Plane 2 (P2), by changing Point 3 to be 2000mm

Page 59

Advanced 4.4.1




Changing the Plane of the Beams and Slabs




Left click on ‘P1’




Right Click and select ‘Move Members to Plane Definition’




Click OK to move the members to the plane

View the 3D screen

Page 60

Advanced


Run the Building Analysis

Viewing the Model and Analysis Results

All the same functions are still available for sloping members. Allowing Deflections and Member Forces to be graphically reviewed in the Analysis Results Display.

Page 61

Advanced 4.5

Modelling Pile Caps




Select all of the 500*500 columns at St00 (Foundation Level)




Right Click and select ‘Insert Pile Cap’, and click OK to create a Typical Base




Make the following settings in the Pile Cap Window This window allows the user to specify the depth of the cap (h), along with the size and spacing of the reinforcement in the pile cap. The pile size/SWL capacities and spacing is also set in this window


Make the settings as shown adjacent




Again make the settings as shown adjacent




Click Analysis

Page 62

Advanced

Orion will calculate the number of piles required in the Pile Group based on the Column Forces. This will also take into account for the effects of moments at the column bases. Lx and Ly are the length and width of the pile cap, along with the number of piles required to satisfy the design forces. Note – At present the scope of the analysis ONLY resolves the forces to calculate the Number of Piles. Orion DOES NOT design the
pile Clickcap, OK, and the 3D model this view remains Beyond Scope.

Page 63

Advanced 4.6

Hint and Tips for Modelling Inclined Members

Hints and Tips 1.

2.

3. 4. 5.

Inter connecting diaphragms can only be specified in the same plane. If diaphragm warnings are ignored in the Building Analysis this will lead to incorrect analysis forces – see Engineers Manual for further details. Inclined Members for beam and columns is perfectly possible for the Building Analysis. However in doing so this may introduce Minor Axis Shear and Bending / Torsion and Axial Tension, which are not checked when designing beam members in Orion. Gravity Loads are applied vertically to inclined members and NOT perpendicular. Concrete and Formwork Quantities do not account for the effects (increase) of inclined members. Finite Element Analysis and Inclined Members – It is possible to run an FE load chase down when Inclined members have been included in the model, however the following limitations must be carefully considered a. FE Analysis will ignore inclined members (slabs/columns/walls/beams) the model is idealised as a series of vertical and horizontal members. b. All inclined members will be assumed to exist at the lower level in the horizontal plane. c. Inclined columns are modelled vertically. However the loads are transferred to the physical location of the column in the storey below, not the vertically projected location. d. FE results should not be merged for Inclined Beams as the shorter horizontal length will be used for the design. e. FE results can be merged for the columns, as the column length will be taken from the BA model. As the column is modelled vertically in the FE model this will create a stiffer column, due to the column being shorter than the inclined length.

Page 64

Advanced

5 Transfer Structures (Beams and Walls) 5.1

Introduction

This exercise will focus on the correct modelling and analysis of Transfer Structures within Orion. There are various different analysis techniques which can be used to determine the analysis forces. The following exercise will focus on the following:-

5.2




•

Transfer Beams

•

Transfer Walls

Transfer Beams – General Method

Open model ‘Transfer_Beams_1’

Page 65

Advanced 5.2.1

Analysis Model Options

Having loaded this model you should confirm that analysis model option settings are made as shown below. Model Tab

5.2.2




Stiffnesses Tab

Settings Tab

Analysis

Check the options as shown above and start the building analysis which should then run with no error or warning messages and be completed as shown below.

Page 66

Advanced

5.2.3

Load Comparison Check

For all structures it is worth looking at the axial load comparison report available after analysis. This report shows up to 4 tables, the first indicates the sum of loads as they are applied to the structure (the “undecomposed loads). The second indicates the sum of loads as they are applied to beams at each level (after “decomposing” slab loads). The third indicates the total column/wall loads derived at each level after the building analysis. The fourth (not shown above) indicates the total column/wall loads derived at each level if an “FE Chase Down” has been performed. In the example above you can clearly see that no loading discrepancies have occurred in either the load decomposition phase or the building analysis phase, the analysis is complete.

Note: In the analysis settings you have the option to define an “Axial Load Comparison Tolerance”, in this example it was set to the default 5%. If the overall totals in the above tables vary by more than this amount Orion will issue warnings at the end of the analysis.

Page 67

Advanced 5.3

Discussion of Frame Analysis Results

5.3.1

Gravity Loads (Mid-Pier Wall Modelling)

The axial loads developed in the columns and walls at second floor level are shown below (by activating the appropriate display setting).

Does it seem strange that the internal columns along grid A do not develop higher axial loads than the corner column?

Page 68

Advanced 5.3.2

Building Analysis Results

The results can be reviewed graphically to see shear force diagrams as shown above and bending moment diagrams as shown below. Note how the side and rear walls are idealised with a single “midpier” element.

Note: Ensure the ‘Diagrams > Rigid Members’ are switched on to allow the effects on the transfer beams to be viewed.

Page 69

Advanced 5.3.3

Front Transfer Beam The member force diagrams for the front transfer beam are shown above. It all looks very reasonable - a peak sagging moment of 579kNm, and end shears of up to 336kN. Notice that the loading diagram does not show applied loads at the transfer column positions. The transfer columns are a part of the analysis model and so the loads they transfer can only be seen in terms of the steps in the shear force diagram, which are clearly visible. Notice the small steps in the bending moment diagram under the supported column positions, these are a small indication of the frame action being developed with the columns themselves, this step could be eliminated by pinning the bottom of the transfer columns. It is noted that there is currently no (easy) way to account for IL reductions within the columns that load the transfer beam, in beams supporting columns with many levels above this means that the transfer beam design will be conservative by default.

Page 70

Advanced 5.3.4

Rear Transfer Beam The member force diagrams for the rear transfer beam are shown above. Again, it all looks very reasonable - a peak sagging moment of 1154kNm, and end shears of up to 415kN.

Note that the wall is idealised as single “mid-pier” element therefore its load is concentrated at the centre of the beam as can be seen from the shear force diagram. Clearly this idealisation will tend to result in conservative design of the transfer beams.

Again the small step at the peak of the moment diagram, is due to the frame action being developed from the wall.

Page 71

Advanced 5.3.5

Frame Action

Now consider the moment diagrams for the continuous beam line at second floor level above the front transfer beam.

Perhaps not what some might initially expect – there is no hogging across the transfer column positions. This is a logical result of any full 2D or 3D analysis, the transverse beam is deflecting, hence the supported columns are deflecting and this has an effect on the beams above. In essence the loads are being shared according to the stiffness’s of the beams at all levels. This effect makes more sense when the deflections for the frame are viewed as shown below.

This also explains the apparently low axial loads noted in the transfer columns at the start of this section.

Note: However, in Orion it is possible to force the entire vertical load to be carried by the transfer beam by using either of the “FE methods”

Page 72

Advanced 5.4

Gravity Loads (FE Meshed Wall Modelling)

If the building analysis is repeated using FE meshed walls the overall results will be affected slightly and there will be some significant local differences which are discussed in this section.

The axial loads developed in the columns and walls at second floor level are shown below (by activating the appropriate display setting). There are very small changes in the distribution of axial loads in the columns and walls. The effect where the internal columns along grid A do not develop higher axial loads than the corner column still applies.

Page 73

Advanced 5.4.1

Building Analysis Results

Once again, the results can be reviewed graphically to see shear force diagrams as shown above and bending moment diagrams as shown below. Note how the side and rear walls are now idealised with a mesh of shell elements.

Front Transfer Beam The member force diagrams for the front transfer beam are very similar to those given by the mid-pier idealisation. The peak sagging moment has increased from 579kNm to 584kNm, and the maximum end shears has decreased from 336kN to 326kN. Overall the change from mid-pier to meshed wall modelling has had no significant impact on the design forces developing in this beam despite the fact that one end of the beam interacts with a wall.

Rear Transfer Beam In this case the shear forces at the ends of the beam are almost unaffected by the change for mid-pier to meshed wall idealisation. The maximum end shear decreases from 415 to 410kN. However, over the length of the wall we can see a series of step changes in the shear force diagram as the wall interacts with the beam this interaction also appears to have the effect of smoothing the BMD and the peak sagging moment drops from 1154kNm to 947kNm. Within the length of the wall the wall itself will provide a much deeper compression zone thus reducing steel tension reinforcement requirements. Within Orion the beam is designed in isolation ignoring this interaction of beam and wall elements. Orion’s design for a moment of 947kNm could therefore still be argued to be conservative.

Page 74

Advanced 5.5

Transfer Walls

Consider the wall at the left hand side of the above model. It stops at first floor level and a beam is placed under this wall despite the fact that there is a column under each end of the wall. On the whole there seems to be 3 engineering approaches adopted in such situations: •

A beam is defined, so the engineer expects the beam to carry all of the wall load.

•

No beam is defined – the wall must be designed to act as a deep beam spanning between the supporting columns.

•

A beam is defined but only for detailing reasons, or perhaps to provide an in-built construction stage support for the wall above. In essence the engineer expects the beam to be ignored or to carry a very small proportion of the load and that the wall should then be designed as a deep beam for the greater part of the load.

Orion provides different levels of support for each of these approaches, we will consider each in turn in more detail.

Page 75

Advanced 5.5.1

Option 1 - Supporting Beam to carry all Wall Load

As was shown earlier in this chapter, if the model is analysed using the mid-pier idealisation of walls then the load is concentrated at the centre of the wall and the beam is designed for a moment that would normally be regarded as conservative. In this case the moment is 905kNm and the sum of the end shears is 716kN. If you want to ensure that a supporting beam is conservatively designed to support all the loads from a wall above we recommend that you use the mid-pier idealisation.

Page 76

Advanced 5.5.2

Option 2 - No supporting Beam – Wall to act as a Deep Beam

Analytically Orion supports this option with no difficulty.


Make a copy of “Transfer_Beams_1” and delete the beam under the wall. Analyse using the mid-pier idealisation and the analysis will proceed with no errors or warnings.

When the analysis model is viewed as shown below you can see this is because Orion creates rigid arms at every floor level of a wall and the arms at first floor level connect to the supporting columns at each end of the wall. The axial loads that develop in the supporting columns can be seen in the view below.

Swapping to a meshed wall and re-analysing similar results can be seen. Once again it is worth noting that even in meshed walls Orion inserts beam elements at each floor level for numerous reasons discussed elsewhere. In the absence of such elements (and in particular in more complex models which include transfer walls) the comparison of results between the meshed and midpier idealisation would not be so good. LIMITATION – The model has been solved analytically, but Orion does not automatically recognise walls which require deep beam design. In the current release it remains essential that a manual design is carried out for all Transfer Wall Panels.

Page 77

Advanced 5.5.3

Option 3 - Beam and Wall to Work Together

If the original model is re-analysed using meshed walls the results for the same beam change as shown below.

The moment has dropped from 905kNm to 263kNm and the sum of the end shears has dropped from 716kN to 562kN. Given that the mid-pier model generates a single central point load where a UDL might be a more realistic we should expect the reduction in moment to be at least in the ratio of WL/4 reduced to WL/8 – i.e. something less than 50% for this single span example. In fact the moment has dropped by approx 70%. The reduction may not be as significant for more complex situations with continuous transfer beams. The stepped shape of the shear force diagram is indicative of the interaction between the shells and the beam. The drop in moments and shears is an indication that the meshed wall has stiffness in its own right and is carrying loads direct to the supporting columns. In conclusion, by using the meshed wall option the transfer beam and wall will both carry load. As is shown in this example the design forces developed in the transfer beam are still likely to be conservative. However, the wall is required to carry some of the load and in this respect the same limitation as is noted for the case where there is no supporting beam is applied. LIMITATION – Where meshed walls are supported by transfer beams, the model is solved analytically, but Orion does not automatically recognise that such walls require some degree of deep beam design checking. In the current release it remains essential that a manual design is carried out for all

Page 78

Advanced 5.5.4

Other Considerations – Walls Supported by more than 1 Beam (for information)

In the adjacent / below view you can see a wall supported at first floor level but it sits on two different transfer beams. If this wall was analysed using the Mid-Pier Method then all the load would be concentrated down the central element of the wall. In this example this would mean all the load would transfer directly to the central supporting columns below. This potentially could lead to unconservative design of the Transfer Beams.

How to resolve this problem? • Use the Finite Element Shells model for the Building Analysis model this will load the beam with a series of point loads along the wall. • Split the wall into 2 walls, 1 either side of the central column below, and use the mid pier model.

Page 79

Advanced 5.6

Transfer Beams – FE Method, Option 1

Alternative methods that have been introduced in Orion to help deal with transfer levels. Both these methods utilise 3D analysis on a floor-by-floor basis, to chase the load from the top to the bottom of the structure, applying the load from the stories above. Option 1 – This option does not include the slab plates, hence in the FE environment relies on the decomposition method from the Building Analysis (Yield Line or FE for Beam Loads). This method is the quicker of the two and can be used if you are not required to design the slabs based on the FE analysis results. Option 2 – This options includes the slab plates, will take longer to run and will allow the slabs to be designed based on the FE analysis results.

5.6.1




Modelling and Initial Analysis

Open model ‘Transfer_Beams_1_FE’ enter the ‘FE Floor Analysis’ and make the settings above. Un tick all the options except ‘Include Upper Storey Column Loads’

‘Include Slab Plates in FE Model’ – If ticked this will mesh the floor plates. If left un-ticked the beams will be loaded based on the Building Analysis Decomposition Method currently selected. ‘Consider Beam Torsional Stiffness’ – This option allows torsion to develop between Beam to Beam connections (traditionally ignored). With this option un-ticked the Torsional Capacity of the beams will be assumed to be negligible.

Page 80

Advanced 5.6.2

Run the FE Analysis & Load Chase Down




Left click the ‘Batch FE Chasedown’ and make the settings below:-




Click ‘OK’




As we have not included the slab plates in the analysis the above Warning can be ignored.




Click ‘OK’

Page 81

Advanced


At ‘St01’ click the ‘Analysis Post Processing’

The view above shows the loads applied onto St01 from above using the FE Load Chasedown, and the ‘Yield Line’ decomposed Beam Loads. Note that the dead loads shown in the discontinuous columns above are similar, but slightly higher than the 64 to 68kN loads determined in the previous chapter.

5.6.3

Axial Load Comparison

Having completed an “FE Chase Down” (sequential FE analysis of all floors starting at the top and working down) you can review the resulting column loads in the Axial Load Comparison Report accessed from the main building analysis dialogue.

Page 82

Advanced

For this model there are no discrepancies, as you will see in chapters 9 & 10 this is not always the case. The most important comparison when reviewing the results of the FE Chase Down (shown in the last table in the report above) is with the first table (the un-decomposed slab loads).

Page 83

Advanced 5.6.4

Merging Column Analysis Results

Having completed the sequential floor analysis column design forces can be updated by merging the results from FE with those from the main building analysis. Column results are merged using the appropriate button on the post-processor tab of the FE analysis dialogue. Let’s look at how the results change before and after merging.

The view above shows column loads before merging. These are the loads from the general building analysis carried out using the mid-pier idealisation for walls and with rigid zones set to “none”.

Page 84

Advanced

The view above shows column loads after merging. Obviously the loads on the transfer beams have increased, but as the axial load comparison shows, the total load is the same at all levels.

5.6.5

Column Design (for information)

Having merged the column results, the columns can be designed in the usual way. Note that you have the option to design them based on building analysis results and then check them based on the merged FE results. The view below shows the column design summary based on the building analysis results. Note that the reinforcement and utilisations may be different on your machine because of different design settings/preferences that you may have set.

Some utilisations are higher, some are lower, it is simply a function of the different axial loads and moments that are generated by the different analytical approaches. Clearly one wall is now failing. This is occurring because the FE chase down is generating higher moments in the wall because of the increased bending in the transfer beam that is connected to it. Any failed members can be filtered out and selectively re-designed.

Page 85

Advanced 5.6.6

Merging Beam Analysis Results (for information)

As with the column results above, the beam results are merged using the appropriate button on the post-processor tab of the FE analysis dialogue.

When you merge beam results a message box will appear confirming whether or not the merge has been successful at each level. Note: It should be noted that when results are merged there will no longer be any pattern load cases results for the beams. Beam Results from the Finite Element Analysis can only be merged when the Rigid Arms in the Building Analysis is set to ‘NONE’

Page 86

Advanced 5.6.7

Discussion of Merged Results

Front Transfer Beam The previous chapter included a section in which frame analysis effects were introduced. In this section we can make some comparisons with those results. The member force diagrams for the front transfer beam are shown below. Note that the beam label is annotated “(FE)” indicating that the diagrams are based on the results of FE analysis. Once again, the shear force diagram clearly indicates the presence of high point loads at the expected positions.

The diagrams are quite similar to those shown in the previous example, in this case the shear forces and moments are a little higher (max sagging moment increasing from around 579kNm to 725kNm). The maximum shear force has increased from around 335kN to 384kN.

All this is to be expected since the FE chase down accumulates all the loading in the columns and applies it to the transfer beam. There is no frame action that generates sharing of load back up to the floor above. In fact, this approach probably more closely emulates traditional hand calculations.

Now we can compare the diagrams for the continuous beam line at second floor level above the transfer beam.

Note: There is currently no (easy) way to account for IL reductions within the columns that load the transfer beam, in beams supporting columns with many levels above this means that the transfer beam design will be conservative by default. If it is essential to try assess the effect of IL reduction this can be achieved by creating a copy model with a new set of load combinations where the IL factor is reduced from 1.6 to say 0.96 if a 40% reduction is required. This model can then be only be used for the design of the transfer beams.

Page 87

Advanced

These results may look more in line with initial expectations than those shown in the previous example, but what is the “correct” answer? Some might say that the sequential nature of construction means that the above style (FE Load Chase Down) of diagrams is more appropriate for the self-weight, this would mean that the “correct” answer lies somewhere in the middle of the two extremes.

Note: Once again, the check design mode for beams can be used, so if you wanted to design for one extreme and then check for the other you can do so.

Page 88

Advanced 5.7

Transfer Beams – FE Method, Option 2 (for information)

This exercise and the previous exercise describe alternative methods that have been introduced in Orion to help deal with transfer beams. Both these methods utilise 3D FE analysis on a floor-by-floor nd basis. This 2P P option is simply a variation of the method described in the previous chapter, but this time using the meshed up floor models. This option is therefore a little more complex, slower, and has a bit more potential for errors arising from modelling anomalies. However, if it is your intention to use FE meshing and analysis for slab design work you will probably find it easier to stick to this option rather than trying to swap back and forth between the two.

5.7.1

The FE Analysis & Load Chase Down

In order to chase the loads down through the building you must once again start at the top floor level and work downwards. • Checking the option to “Include Slab Plates in FE model” means that you will need to “mesh up” the floor slab as shown later – This is the difference between Options 1 and 2. • Including or excluding beam torsional stiffness will make little difference to the overall validity of the load chase down. (However, engineers have traditionally calculated forces in floor grillage systems without allowing for torsion and Orion does not consider torsion within beam design.) • The theoretical stiffness of the slab relative to the beams can make a big difference to the load paths and influence the design moments determined in the beams. For this example set the slab stiffness multiplier to 0.2. You could also adjust the relative stiffness of the beams. Orion uses the gross sectional area of the beams (ignoring flanges) and columns by default, so you might make this adjustment to allow for the flanges. In this example leave the beam stiffness multiplier set to 1.0. Changing the slab stiffness multiplier to 0.2 will allow the transfer of load to the beams then the columns, rather than by-passing the beams and transferring some load directly to columns (like a flat slab).

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Advanced After analysis, the post-processing option allows graphical review of the applied loads and other results. The picture below shows deflection contours together with the applied nodal loads for the Dead Load case.

Note that the dead loads shown in the discontinuous columns above are quite similar to those determined in the previous example (option 1).

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Advanced 5.7.2

Discussion of Merged Results

Front Transfer Beam - The diagrams are quite similar to those shown in the previous exercise (option 1), in this case the shear forces and moments are a little higher (max sagging moment increasing from around 725kNm to 745kNm). The maximum shear forces have also decreased slightly.

Effect of adjusting Slab Stiffness Factor


To illustrate this effect, repeat the sequential FE modelling and analysis this time using a slab stiffness factor of 1.0.

On completion you can merge and compare the column forces, and as you might expect, you should find that the column force distribution is not greatly affected. However, let’s now look at the beam design forces that will get merged. The member force diagrams for the front transfer beam are shown below. The hogging and sagging moments on the transfer beam have both reduced slightly by increasing the Slab Stiffness Multiplier to 1.0.

Note: When merging the beam results the loads will be shown as a red rectangle. This is because the beams and slabs both form part of the FE analysis model, hence no longer relies upon decomposition to the beams then the columns.

The shears at each end of the beam have also dropped. In this example the differences are not very dramatic, but in other examples you may well find that they can be.

The effect that is occurring is that the slabs are carrying a proportion of the load straight to the supporting columns and by stiffening the slab the effect gets bigger.

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Advanced 5.7.3

Summary of Transfer Beam Results

Analysis Type

Slab Decomposition Method Yield Line or FE for Beam Loads

Front Beam Max Shear (kN) / Moment (kNm) 336kN 579kNm

Rear Beam Max Shear (kN) / Moment (kNm) 415kN 1540kNm

2. Transfer Beam General Method – FE Wall Method

As above

326kN 584kNm

410kN 947kNm

3. Transfer Beam – FE Load Chasedown – No slab plate

As above

384kN 725kNm

Not considered

4. Transfer Beam – FE Load Chasedown – including slab plates

FE Floor Analysis

337kN 745kNm

Not considered

1. Transfer Beam General Method – Mid Pier Wall

Notes

Frame Analysis BA results Only Central Point Load created for wall load onto beam Frame Analysis BA Results Only Shell model for wall, creates a series of smaller point loads on beam Yield Line or FE for Beam Loads used for decomposition No slab plates included No Framing action Punishes Transfer Beam, level by level load transfer Slab Stiffness considered as part of the FE analysis No Framing action Punishes Transfer Beam, level by level load transfer

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Advanced

6 Transfer Slabs The previous chapter showed the option to load a meshed up floor model with column loads accrued from upper levels. Since there is no necessity for a column node to sit on a beam, this solution simply re-utilises the same sort of meshed floor model option at the transfer slab level.

6.1

Modelling and Initial Analysis

For Transfer slabs the solution method is essentially the same as for transfer beams. Consider a revised version of the simplified model used in the previous transfer beam examples.




Open model ‘Transfer_Slab_1’

Note: All the beams have been removed at first floor level and a deep flat (transfer) slab has been created.

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Advanced

Note: Every column and wall sits at the edge but not necessarily at a corner of the slab panel. It is important that you do not define slabs that simply span over or under internal columns and walls. You can 6.1.1 Building Analysis check whether you have defined such slabs
accidentally Run the building analysis. During the analysis errors will be displayed as shown below, by running a

but you will have the option to continue. The first message shown below lists columns and walls that the system regards as unsupported. This basically means columns and walls that stop at an upper floor level and which do not sit on a beam.




Press Ok when the message above appears

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Advanced

This confirms that the load has gone missing in the model. This should be a clear indication that to achieve the correct results, an FE analysis will be required. There are no beams for the slab loads to decompose

The first warning is telling us that only 35% of the applied load is being applied successfully decomposed onto beams and hence included in the building analysis. Essentially this is also telling us that the building analysis results are of little value. At this point it is worth examining the structural model that has been created and analysed.

The problem is very obvious, the two front columns and the wall at the rear do not sit on anything, so the loads in these frames actually reach the end wall and columns by virtue of beam and Vierendeel action at the upper level.

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Advanced 6.1.2

Alternative Modelling Option (for information only)

Clearly this is quite a regular model and in such cases you can make use of the option to define “Support Band” beams as shown below.

In this example Support Band beams are defined along grids A and B.

Note: Support band beams are in a sense fictitious beams that allow you to generate a coherent building analysis model but these aremodel not passed For this beams particular the edits shown above mean that the Building Analysis will run with no errors the FE model, theyload do comparison will be perfect – no missing loads. This may initially seem to orto warnings and thesoaxial the FEfor results. benot theaffect best option dealing with transfer slabs, and for simple/regular models it probably is. However, Theof Default width of the we see, and especially those involving flat slabs and transfer slabs, are not most the “real” models beam will be often L/4 ofbe the regular. It can very difficult to insert a logical system of band beams. short edge of the slab.

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Advanced 6.1.3

The FE Analysis & Load Chase Down

In order to chase the loads down through the building using this model, you could stick to exactly the same sequence and settings as were used in the previous chapter. However, let’s take this opportunity to illustrate that you can swap between the simpler and more complex modelling options at different levels: Start at the top level and work downwards, using the FE (Batch) Load Chasedown

Make the settings as follows for the FE Load Chasedown







Note: On floors St02 and St03 we have unticked the option to include slab plates in the FE Model. This means the beams in the model will be loaded based upon the BA decomposition for loading.

The warning above is displayed as there has been no adjustment made for the Long Term Effects to allow for Cracking / Creep and Shrinkage. As this is discussed in other areas it will be ignored in this example.

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Advanced 6.1.4

Storey 1 (St01) slab results

After analysis use the options for graphical review of the applied loads. The picture below shows the accumulated dead loads applied at the first floor level in this example model together with the deflected contours for that case.


Go to the Analysis Post-Processing and Reports and enter the Analysis Post-processing at St01

After the analysis, you can see moment and deflection contours for the transfer slab that take account of the supported column and wall loads. For this example we will look quickly at some of the slab results, which can quickly be exposed using similar techniques to those used for the Flat Slab Example.

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Advanced 6.1.5


Storey 1 (St01) Slab Results – Cutting Slab Strips

Select the Strip Tool, and a Half Band Width of 1.0m and cut the strip as shown below holding ‘Ctrl’ to make to snap to the Horizontal location.

In the view above we can see a contour diagram in the background showing design sagging (tension in bottom) moments generated in the longer span direction of the slab. On top of that is a section view showing design moments on a line (red dots along the centre of the strip) cut in the same direction. The contour plot above Md1-bot is only showing the sagging moments (hogging moments are not displayed).

Note: Only when the Design Moment is selected are you looking at results which include for the effects of ‘Wood and Armer

Adjustments’

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Advanced 6.1.6


Storey 1 (St01) slab results – Integral Strips

Maintaining the same strip switch to the ‘Integral’ and ‘Req. Steel Area’, shown below:-

By changing to an ‘Integral’ and ‘Req. Steel Area’ strip, we can see the results captured and averaged over a specified the width of strip, in this case a 1m wide strip at the edge of the slab. Using this average value the area of steel could be determined for both the sagging (bottom steel) and the hogging (top steel), based on the average over the strip width specified by the user.

Notes: The above results will be affected by the ‘Concrete Effective Depth’ settings and also the position and width of the strip under consideration. Slabs could also be reinforced using the same methods as described in the Flat Slab Example in today’s earlier in this manual. Providing the required amounts of steel relative to the exact contour values throughout the floor plate. It should also be noted, although Orion can perform Punching Shear Checks for slabs sat on columns, it remains Beyond Scope to check for Punching Shear requirements when a column sits on a transfer slab.

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Advanced 6.1.7

Review of the Axial Load Comparison Report

Once again, having completed an “FE Chase Down” (sequential FE analysis of all floors starting at the top and working down) you can review the resulting column loads in the Axial Load Comparison Report accessed from the main building analysis dialogue.

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Advanced For this model we still have the discrepancies occurring during load decomposition and building analysis that are discussed earlier in this chapter. However, the results for the FE Chase Down (shown in the last table in the report above) compare with the sum of applied loads in the first table (the undecomposed slab loads). This means that the FE Chase Down procedure appear to have been successful and we can now continue to ‘merge column and beam design forces’.

6.1.8


Merging Column Analysis Results

Tick the boxes shown below to Merge both the Column and the Beam (G and Q) loads from the FE Load Chasedown analysis:-

Having completed the sequential floor analysis column design forces can be updated by merging the results from FE with those from the main building analysis. You can then design columns or check previously designed columns for these new slightly different loads.

6.1.9

Merging Beam Analysis Results

As with the column results above, the beam results are merged by checking the appropriate button on the post-processor tab of the FE analysis dialogue shown above. The notes in the previous chapters regarding the way these FE Chase Down methods concentrate the loading in the lowest beam are equally applicable here, but in this case it applies to the slab. For the beams at the upper floors the design moments from the building analysis may or may not be meaningful, it will depend on which of the modelling options discussed earlier in this chapter you have used. If they are not useful you will be restricted to designing the beams for the merged FE results. It is likely that the use of the alternative modelling option (earlier in this chapter – Support Band Beams) is most likely to generate meaningful design information in the building analysis phase.

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Advanced

7 Diaphragm Modelling 7.1

Introduction

In a typical building lateral resistance is provide at a few discrete points and it is assumed that applied lateral loads will be distributed to the lateral load resisting systems via floor diaphragm action. Within Orion diaphragm modelling is achieved using diaphragm constraints. A diaphragm constraint will maintain exact relative positioning of all nodes that it constrains, i.e. the distance between any two nodes constrained by a diaphragm will never change, and therefore no axial load will develop in any member that lies in the plane of a diaphragm between any two constrained nodes. When running the building analysis the model options tab gives options as shown below.

7.2

Diaphragm Modelling Options:

For the diaphragm modelling there are 3 options: •

Slabs to define rigid diaphragms (Default Setting)

•

Single rigid diaphragm at each floor level

•

No rigid diaphragm floor levels

The differences between these options can be demonstrated with the simple model shown below.

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Advanced

A single floor level has 2 separated slab areas that are linked by 2 beams. Within the main graphics window Orion will always indicate a single overall centre of mass for the entire floor level as shown below.

It is important to note that in the case of discrete diaphragms, or when there is no diaphragm at all, this overall central location is provided for information only.

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Advanced 7.2.1

Slabs to define rigid diaphragms (Default Setting)




Go to Building Analysis and ensure that on the Model Options tab the diaphragm setting is as above. Then run the Building Analysis.




After analysis has been completed go to the model and deformation plots view.

With the above setting Orion finds any discrete areas of interconnecting slabs and sets up discrete diaphragms as appropriate. Separate notional loads are calculated and applied to each diaphragm area. These applied notional loads and the resulting sways can all be examined in the model and deformation plots view. Perhaps the easiest way to see that 2 discrete diaphragms have been created is to look at an exaggerated view of deflections.

For each of the two diaphragm areas a separate centre of mass location is determined and the notional load is applied at that position. The view above shows the values for the Fy case in this example. Note that the mass of the walls increases the applied notional load in the left hand diaphragm area. Clearly the right hand area is moving independently to the left hand area which is better restrained by the walls as opposed to frame action.

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Advanced 7.2.2


Single rigid diaphragm at each floor level

Return to the Model Options tab and specify a single rigid diaphragm at each floor level. Then re-run the Building Analysis.

With this setting Orion will apply a single diaphragm constraint to every node at any given level. The existence of slabs is completely ignored/irrelevant. A single notional load is calculated and applied at the overall centre of mass as shown below. Once again the easiest way to see the effect of this setting is to look at an exaggerated view of deflections.

This time we can see the entire level translating and rotating as a unit, since the centre of mass and hence the applied notional load is very eccentric to the core walls, the dominant effect in this example is one of rotation.

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Advanced 7.2.3


No rigid diaphragm floor levels

Return to the Model Options tab and specify the above diaphragm setting. Then re-run the Building Analysis once more.

If you have defined slabs but for some reason you do not wish a diaphragm effect to be considered you can completely eliminate diaphragm constraints using this option. In this case notional loads are applied separately at every node in the floor level, these applied notional loads and the resulting sways can all be examined in the model and deformation plots view. Once again the easiest way to see the effect of this setting is to look at an exaggerated view of deflections.

The frame that is restrained by the wall hardly moves at all, other frames move to differing degrees. Note that the frames which do not include walls have the same stiffness and so the differing deflections relate to differing notional loads.

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Advanced 7.2.4

Excluding Specific Slabs from Diaphragms




Return to the Graphic Editor and create a linking slab between grids 4 and 5, using the same properties as used for the existing slabs.




Edit the properties of the slab and exclude it from diaphragm as shown above.

In this case you can still use the default option “Slabs to Define Rigid Diaphragms” and the resulting deflections will be the same (ignoring small change due to additional notional load from the added slab) as were shown above for that option.

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Advanced Note: If the linking slab was substantial you might consider that it maintains the diaphragm action between the two areas. However, as the link becomes more slender then at some point you will decide it cannot maintain diaphragm action between the two areas. We can model this latter case as follows.

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Advanced

8 Duplicate Floors 8.1

FE Chase Down with Duplicate Floors

8.1.1

For Information

In the simple example in this chapter information has been defined at all three levels of the building. It is possible to have duplicate floor and have these dealt with automatically as part of the FE Chase Down procedure without the need to mesh and analyse them. However, there are more restrictions on what can be regarded as valid duplicate when the FE sub-frame models are involved. The FE model for each floor includes the columns and walls above and below that floor, so for the models to be identical the wall and column arrangements above and below identical floors must also be identical.

Consider the 10-storey model above. The folders indicate that information is defined at upper levels 10, 9, 6, and 1. From a beam layout point of view level 9 might be identical to level 10. However there are no columns above level 10 so the FE models at these two levels will never be identical. Hence it is always necessary to create information and generate the FE models at the top 2 levels in any model if an FE Chase Down is to be used. In the model above 7 and 8 are valid duplicates of level 9. Level 6 has information, the model takes up an increased plan area and new columns start from this level.

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Advanced For the same reasons as at the top two floors, level 5 is not a valid duplicate of level 6. If you try to work through an FE Chase Down for this model then you will get a message as shown below when you try to create the model at level 1.

By copying storey information from level 6 to level 5 this model will have information at enough floors for an FE Chase Down to be completed. Note that information is always required at level 1 and therefore as an absolute minimum in any model nd information is required at 3 levels, Top, 2 Top, and First.

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9 Importing a .DXF Drawing 9.1

Introduction

In the simple example a drawing is imported from .DXF into Orion this drawing can then be used for the following:•

Automatic Import of Axis (see notes below)

•

Automatic Import of Column Sections (see notes below)

•

Use the DXF as a Ghost Layer to accurately create the elements and loads

•

Snap to locations on the .DXF

•

Import a different .DXF at each level (St) of the structure

•

Provides quick effective checking for changes to the scheme by importing revised drawings




Create a New model (this is a modelling exercise so the settings are not important)




Apply the Drawing Sheet Settings as shown and a Storey Height of 3000mm

Note: With the sheet origin set to 0,0 this will mean the lower left of the drawing sheet will be at 0,0. This is important to relate this point back to the same location in the dxf drawing.




Click on the ‘External Reference File’ icon

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This screen will allow the import of .DXF drawings into Orion at any storey.




Please note the following recommendations before considering the Import of any .DXF into Orion.

• Tidy the .DXF before importing – Do not import all the information in the DXF, are bathroom tile locations really necessary for the creation of the structural model? The less information on the .DXF the less likely mistakes are going to be made during the creation of the model. It may be you create a separate drawing solely for import purposes. • Axis will only be recognised within the Orion model if they are separated into a Unique Identifiable Layer, drawn as a LINE object • Columns will only be recognised within the Orion model if they are separated into a Unique Identifiable Layer, drawn as POLYLINE objects • Ensure the Lower Left corner of the .DXF drawing is consistent in location with the Lower Left corner of the sheet in Orion, to ensure the correct import location in Orion


Click the DXF Load option to bring in the .DXF drawing




Select the Drawing ‘DOC_Example_06-Plan_01a.dxf’




Import the drawing in mm

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Click the DXF Load option to bring in the .DXF drawing

If the tick box for ‘Display Reference Drawing’ is selected, you should be able to see the drawing in the background.




Click Import Members and make the settings below:-

Ticking the ‘Import Axes’ option will allow the layers to be used for active Grid Lines in the model. In this case a layer has been set up for direction 1 and direction 2 axes. But ticking the box to Group Axis by Directions will automatically apply this to a single axis layer drawing. Ticking ‘Import Columns’ option will allow the layers to be used for Active Columns in the model.

Note: Only Axis and Columns can be imported all other elements have to be created manually.

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Click on OK, which will then automatically open the ‘Building Model Check’ this will check for errors in the imported members and axis.




Close this window after the check has been performed




Click the Save icon in the Reference Drawing Settings so the drawing will be saved to the model files.




Go to the Layer Control, where you will be able to switch the Reference Drawing on/off and change its colour

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Click the Object Snap Settings and make the following settings. This will allow you to snap to the drawing you have just imported into Orion




Click the Save icon in the Reference Drawing Settings so the drawing will be saved to the model files.




Click on the Axis Tool and left click and drag to create the four additional axis shown below, 2’1 , 4’1 , B’1 and D’1

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Create the Walls (250mm wide) using the .DXF as a template for their insertion




Do the same for the Beam at the front of the C shaped Shear Core – 250w x 500dp




Insert all the 300mm thick slabs with an Additional Dead Load of 0.5kN/m2, and an Imposed Load 0.5kN/m2.

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Inserting Slabs Your Trainer will demonstrate all the different techniques for inserting slabs in Orion Each has its own merits, which you use is your decision.

. The ‘Beam Region’ is of no use for Flat Slab models due to the absence of Beams. This is to be used only for Beam and Column Examples, as shown in Day 1. Note: Before creating the slabs in a Flat Slab model it is paramount that the layout of the slab panels is given consideration, and the following guidelines are met:• All columns and walls must lie on slab boundaries • Slab boundaries sharing the same grid line will be

Building Analysis > Building Model Validity

When this structural level is complete and before copying to the upper levels, perform Building Model Validity Check


Go to the Analysis > Check

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10 Training Presntation Slides

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