Staad Pro -Dome

ADVANCED STRUCTURES-CONICAL DOME STRUCTURE ******** Data: Spherical dome Dia Dome Base Dia Height of column No. of Columns support Column dia. Connecting beam size Dome thickness Concrete Grade Steel Grade

: 20m : 15m : 7.0m : 16 : 0.45m : 0.38 x 0.23m : 0.10m : M20 : Fe 415

1.Geometry Creation : New Project  Select  Space Units: Length =meters; Force=KN; File Name=Conical dome  Next. Select  Add beam Finish. Geometry Run structure WizardSelect Frame models from Truss modelGo to Surface Plate ModelSpherical Surface. Type Spherical cap. Diameter of Sphere=20m; Base Diameter=15m; Top diameter=0 Latitude: Divisions=10

Longitude: Divisions=15  Apply Transfer ModelYes

Paste Prototype Model X=0 Y=0 Z= 0Ok.

Fig. 1 Spherical Dome geometry Isometric view. Click one end of the nodeEdit CopyPaste Y=-7mOk. Right ClickAdd Beam. Join the column of top & Bottom nodes.

Fig. 2 Adding column to the dome

Select the column member Right clickInsert node Click Add mid pointOk. Select the column Go to GeometryCircular RepeatNode=161 Y Total angle=360 No. of steps=16 Tick □Link steps

□ Open base Ok.

Fig. 3 circular repeat for creating column Select the columns & Beams structure Go to LabelsStructure : inner plates: Blue: Outer Plates: RedOk.

Fig. 4 Geometry of model created

Fig. 5 Structure after selecting labels and Fill with plate 2. Member Property : Click General  Property Define Circle YD=0.45m (Column) Add. Rectangle YD=0.38

ZD=0.23 (Beam)  Add  Thickness node

1,2,3&4=0.1m (Dome thickness) AddClose. Highlight YD=0.45 & Select  Beam Parallel toY  Assign to selected beam  Assign Yes. Highlight YD=0.38 ZD=0.23 and select Top ring beam and middle tie beam member Assign to selected beam  Assign Yes . Highlight thickness=0.1m & select plate cursor. Select Top Dome Structure Right click Labels Structure None Tick □ Fill Plates/solids surfaceApplyOk. 3. Supports : Click Support  Create  Fixed Add. Highlight support 2 and select bottom most nodes of column by windowing using node cursor   Assign to selected nodes  Assign Yes  Close  De select the nodes and change to beam cursor.

Fig 6 Assigning Support as fixed 4. Loading : Click Load case Details Add. Primary Number 1 Loading type: none Title: Load case 1  Add . Click Load case 1 details Add. Self weight Y Factor=-1 Add. Plate loadsPressure on Full Plates W1=-1KN/m2 GY Add. Highlight selfweight Select geometry cursor & select entire structure Assign to selected beam/plates  Assign Yes. Highlight Plate Load pressure on full plates W!=-1KN/m 2 .Select Plate cursor & choose entire structure of the domeSelect geometry cursor & select entire structure Assign to selected beam/plates  Assign Yes. Click Load case details Add. Click Define Combinations  Load Number: 2 Name: 1.5 Load case 1  Normal Factor Default :1.5 Select Load case 1

α1=1.5  AddClose.

5. Analysis Type: Click Analysis/print  No print  Add Close. Click post print Define commands Load list select Load comb AddClick

Analysis Results Add Close, Note: Save the File before Run the Program. 6. Design : Click Design ConcreteCurrent code :IS456 Define Parameters Fc=20,000KN/m2 Add. Click Design commands  Design slab elements  AddClose. Highlight Fck=20000 and select plate cursor and select dome structure  Assign to selected beams/plates  Assign Yes. Go to top view & view the entire elements of the dome in plan. Select one segment of all elements of dome for design of slab portion. 7. Analysis: From Main Menu  ` Analysis  Run Analysis  Done. 8.Results :  Go to post processing mode. Select load case 2 Load comb Ok. Click Summary of results given in Table form. Results  Plate stress contour  Select Load case 2 Load comb Stress Type: Max Von Mz Apply Ok.

Fig. 7 Max. Von Mz

Fig. 8 Max. Von Mz –Isometric view

Fig.9 Max. Von Mz – Top view

Results  Plate stress contour  Select Load case 2 Load comb Stress Type: Mx (Local) Apply Ok.

Fig. 10

Mx (Local)

Results  Plate stress contour  Select Load case 2 Load comb Stress Type: My (Local) Apply Ok.

Fig. 11 My (local)

Go to Staad output Concrete design and see the reinforcement of Dome slab.

Fig. 12 Dome slab Max. & Min. Reinft.