Structural Modelling using Etabs 2018

Aim-

• To model an apartment with all seismic consideration based on given architectural plan.
• To know how to check the seismic performance of an apartment using ETABS.

Required Data for ETABS Analysis-

• Pinned support, Base+9 story +1mumty
• Assumed column size- 450X650mm, Beam -400X500 mm, Slab Thick-150mm, Shear wall 300mm thick
• Live load-2.5 kN/Sqm, Floor finish – 1.5 KN/Sqm, Wall Load-5 KN/m, Water tank=20K= 200 KN

Conceptual design consideration-

1. Re-entrant & cutout check & modification
2. Vertical irregularity- In this structure ground floor is parking area and above floor is residential ,so it is vertical irregularity, here working soft story mechanism.
3. Planner Irregularity- Structure looking in plan is symmetrical .
4. Shear wall area taking with respect of building is 2%

Procedure of geometric model and ETABS analysis- Define material , section property , Load pattern, load case & combination, Shear wall pier label, mass source. Draw grid , story, column , beam, shear wall, floor, assigned load, label etc. Then check model and run analysis.

Checks after analysis and result-

• Model mass participation for first 3 modes dominates at least 65%

Result- Here in my structure, first 3 model mass perticipation is more than 65 % in X-Direction.

• Mode-1 & mode-2 differs by 10%

Result- Mode -1 & 2 differs by 10% so it is achived.

• Principal modes be greater than Torsional mode

Result- Modal 1 & 2 is greater than modal 3 so it is ok.

• Inter Story drift ratio limited to 0.004

Result- Max story drift is within limit.