Etabs Design of Tall Building Reinforcement Detailing

www.mosttutorials.blogspot.com

EGN-5439 The Design of Tall Buildings Lecture 40

ETABS – Getting Started

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Disclaimer Disclaimer by by Computer Computer and and Structures Structures Inc. Inc. “Considerable “Considerable time time and and expense expense have have gone gone into into the the development development and and documentation documentation of of ETABS. ETABS. The The program program has has been been thoroughly thoroughly tested tested and and used. used. In In using using this this program, program, however, however, the the user user accepts accepts and and understand understand that that no no warranty warranty is is expressed expressed or or implied implied by by the the developers developers or or distributors distributors on on accuracy accuracy or or the the reliability reliability of of the the program. program. The The user user must must understand understand the the assumptions assumptions of of the the program program and and must must independently independently verify verify the the results.” results.” In In other other words, words, itit becomes becomes the the structural structural engineer’s engineer’s responsibility responsibility to to check check the the ETABS ETABS results results via via simple simple assumptions assumptions and and hand hand calculations. calculations.

ETABS ETABS allows allows the the user user to: to: Create Create and and modify modify computer computer models. models. Create Create structural structural elements elements (columns, (columns, slabs, slabs, shear-walls, shear-walls, beams). beams). Analyze Analyze multiple multiple scenarios scenarios and and conditions, conditions, such such as, as, Earthquake Earthquake and and wind wind loads, loads, Sequential Sequential loading loading of of construction, construction, When When the the analysis analysis is is run, run, itit goes goes from from an an object object based based to to an an element element based based model, model, The The analysis analysis consist consist of of frames, frames, joints, joints, linked linked with with shell shell elements. elements. Design Design and and optimize optimize multistory multistory buildings buildings (steel/composite, (steel/composite, concrete concrete frame frame and and shear-walls.) shear-walls.) All All these these steps steps through through aa single single graphic graphic user user interface interface (GUI). (GUI).

Initial Initial steps steps to to model model aa building. building. 1. 1. Define Define the the building’s building’s geometry geometry (it’s (it’s footprint, footprint, including including the the adjacent adjacent structures, structures, establish establish the the gridlines, gridlines, etc…). etc…). 2. 2. Consider Consider the the implications implications of of the the geographic geographic location location of of the the building. building. 3. 3. Establish Establish the the codes, codes, analysis analysis procedures procedures and and design design criteria criteria to to be be applied applied (for (for example, example, ASCE ASCE 7, 7, UBC, UBC, IBC2000, IBC2000, Florida Florida Building Building Code, Code, ACI ACI 318). 318). 4. 4. Define Define the the loads loads (dead, (dead, live, live, reduction reduction factors, factors, wind wind and and seismic). seismic). 5. 5. Choose Choose the the structural structural elements, elements, such such as as columns, columns, shear-walls, shear-walls, etc. etc. 6. 6. Define Define the the working working units units (for (for example, example, lb-in, lb-in, kips-ft, kips-ft, etc.). etc.). 7. 7. Define Define the the various various concrete concrete strengths strengths (eg, (eg, 4000 4000 psi, psi, 8000 8000 psi, psi, etc.). etc.). 8. 8. Define Define the the modulus modulus of of elasticity elasticity for for concrete. concrete. 9. 9. Define Define and and create create columns columns sizes sizes and and strengths strengths for for all all different different levels. levels. 10. 10. Define Define wall wall strengths strengths and and thickness. thickness. 11. 11. Define Define steel steel strength strength and and modulus modulus of of elasticity. elasticity. 12. 12. Place Place columns columns and and shear-walls shear-walls upon upon the the gridlines. gridlines.

www.mosttutorials.blogspot.com Parameters:

Columns 30”x 30” Beams 24”x 24” Shear walls: Outer walls: 84” / Inner wall: 24” Transverse wall: 8”

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Shear Wall Preliminary Design



Define a New Model


• Choose “NO”



Define the 1st story.

o Choose “Grid Only”. o Model of 1 story properly, run analysis, and check for any improperly connected nodes.

Alternatively, Alternatively, use use ETABS ETABS’’ uniform uniform grid grid spacing. spacing.

… … or or ETABS’ ETABS’ custom custom grid grid spacing. spacing.

Ready to begin:

Define Properties: - Material Properties - Frame Sections - Slab/Wall Sections - Static Load Cases - Load Combinations

Material Properties: Add new material

…or …or define define material material properties properties (for (for example, example, concrete concrete of of f’ f’cc == 44 ksi). ksi).

Frame Sections Add new Rectangular Sections

Place Place the the concrete concrete columns columns on on the the grid. grid.

Add Beam

Add Wall Sections - Always choose Shell for walls and slabs.

- Membrane and Plate are remnants from previous versions.

Add the slab.

Define the Load Cases The Self Weight is to be counted as a dead load.

Load Combinations DDL = Design Dead + Live SDL = Service Dead + Live

Draw the columns

Draw the beams

Delete the beams and columns to place the shear walls.

Draw the shear walls.


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Draw the slab.


Turn on the Object Fill.

Delete the slabs inside the core.


Draw the slabs around the core.


Mesh the slabs.

Select the frame elements that overlap the shear walls.

Delete the overlapping frame elements.

Apply the Loading.

Apply the Loads.

Run Analysis: - Run analysis and view animation looking for any disconnected nodes/abnormalities. - Resolve all errors before proceeding.


Replicate all stories.


Edit the story data.

Modify the story heights.

Place a slab above core.

Assign loading to the new slabs.

Run the analysis.

View Bent B.

Show the member Forces.

Zoom in to lower stories.

Right-click on the lower middle column to view the Forces.

DILBERT DILBERT



Etabs Design of Tall Building Reinforcement Detailing

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