Staad Training - Module 3 - Malaybalay City June 2011_2

OUTLINE 1. INTRODUCTION 2. BEAM DESIGN 2.1. FLEXURE 2.2. SHEAR & TORSION 2.3. DESIGN FOR ANCHORAGE 2.4. STAAD PRO INPUT PARAMETERS 2.5. STAD DESIGN OUTPUT FOR BEAMS 2.6. SEISMIC REQUIREMENTS FOR BEAMS

OUTLINE 3. COLUMN DESIGN 3.1. COLUMN INTERACTION DIAGRAM 3.2. STAAD DESIGN BRIEF FOR COLUMNS 3.3. STAAD DESIGN OUTPUT FOR COLUMNS 3.4 SEISMIC REQUIREMENTS FOR COLUMNS

4. CONCLUSION

1. INTRODUCTION •

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Analysis part is always followed by the design part. However, it must be noted that the initial proportioning of beam and column sizes is part of the design and may not be the final dimension. Thus the design is a series of iteration and resizing, resizing, then reanalysis, then redesign.

1. INTRODUCTION Design is an iteration process: 1. Initial sizing of beams and columns. 2. Analysis for stresses. 3. Design of steel reinforcements. if design is inadequate, repeat step 1, 2, and 3. 4. If design is adequate, adopt sizes and reinforcements.

1. INTRODUCTION •

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All concrete design calculation is governed by the current ACI 318 code. Unified (strength) design method is adopted by the current code. The working stress design (WSD) is deleted from the ACI 318 code STAAD Pro do not employ the WSD for reinforced concrete design.

1. INTRODUCTION •

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SPECIAL MOMENT RESISTING FRAMES (SMRF) are the type of frames, instead of ORDINARY MOMENT RESISTING FRAMES (OMRF) are required for high seismic risk areas, such as the Philippines. Therefore, the NSCP requires that all buildings in the Philippines must be designed to effectively resist high seismic forces.

1. INTRODUCTION •

At the moment, STAAD Pro has NO provision for automatic seismic detailing in reinforced concrete design.

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What shall we do????

2. BEAM DESIGN • FLEXURE • SHEAR • TORSION

2. BEAM DESIGN 2.1. FLEXURE The main (longitudinal) reinforcement is calculated for midspan (sagging) and support (hogging) bending moments on the basis of the section profile in the design brief (ie (ie.. PRISMATIC ZD, YD).

2. BEAM DESIGN CRITICAL HOGGING MOMENT CRITICAL HOGGING MOMENT

ZONE 1

ZONE 2

CRITICAL SAGGING MOMENT

ZONE 3

2. BEAM DESIGN 2.1. FLEXURE The STAAD Pro does not have any limit of any bars in any one layer as long as the spacing requirements specified in the code are satisfied. The program can handle a maximum of four layers of reinforcement, two layers each at the top and bottom.

2. BEAM DESIGN 2.1. FLEXURE The actual amount of steel required as well as the maximum and minimum required for flexure is shown as ROW, ROWMX AND ROWMIN, respectively. It is important to note that the beams are designed for flexural MZ only. The moment My is not considered in the design.

2. BEAM DESIGN 2.1. FLEXURE

MY h

Top bars (max of 2 layers) MZ

x

bottom bars (max of 2 layers)

y b

2. BEAM DESIGN 2.2. SHEAR & TORSION COLUMN ELEMENT LINE STEEL REINFORCEMENTS

d BEAM ELEMENT LINE

d SFACE OR EFACE

SHEAR FORCE AND TORSIONAL MOMENT LOCATION CALCULATED

2. BEAM DESIGN 2.2. SHEAR & TORSION When required, torsional reinforcement in the form of closed stirrups or hoop reinforcement must be provided.

2. BEAM DESIGN 2.2. SHEAR & TORSION

2. BEAM DESIGN 2.2. SHEAR & TORSION In addition to the stirrups, longitudinal steel bars are provided in corners of the stirrups and are well distributed around the section

2. BEAM DESIGN 2.2. SHEAR & TORSION

2. BEAM DESIGN 2.2. SHEAR & TORSION In the ACI Code, the design for torsion is based on space truss analogy. After torsional cracking occurs, the torque is resisted by closed stirrups, longitudinal bars, and concrete compression diagonals.

2. BEAM DESIGN 2.3. DESIGN FOR ANCHORAGE In STAAD output for flexural design, the anchorage requirement is shown with a YES or NO at the START and END of the beam. The designer must provide the details of anchorage.

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