PERFORMANCE BASED BEHAVIOUR OF R.C. BUILDINGS USING PUSHOVER ANALYSIS

Abstract

In the present study the performance of an irregular 12 storey building with offsets at every 3 storey has been studied using pushover analysis. ETABS Nonlinear v.9.2.0 has been used for the design, analysis and determination of the response of the building under pushover analysis. The building is designed for wind loads, 5% torsional forces along with gravity loads and seismic loads. The building is designed with and without considering the strong column weak beam design philosophy and the results were compared. To account for soft storey effect beams and columns in the open ground storey are designed for 2.5 times the storey shears and moments obtained from the bare frame analysis. The response of the building under 5%, 10%, and 15% and 20 % torsion has been 4 cases For SC-WB design philosophy, 4 cases soft storey effect and 8 cases for torsion effect Totally 16 analysis cases have been carried out to examine the each parameter. kv It is observed that due &he effect of strong column — weak beam design the base shear increases from 12594 kN to 12703 kN in long direction of the building, and the base shear increases from 6642 kN to 6966 kN in short direction of building. The increase is insignificant. Due to soft storey effect the base shear increases from 12594 kN to 13673 kN in the long direction, and 6642 kN to 7167 kN in the short direction~In longitudinal directio9, the base shear decreases from l3673kN for 5% torsion to 13606 kN for 10% torsion, 13574kN for 15% torsion and 13550kN for 20% torsion, and in transverse direction, the base shear is reduced from 7167 kN for 5% torsion to 6072 kN for 10% torsion, 5624 kN for 15% torsion and 13550kN for 20% torsion. The results show that torsional effects are more in short direction rather than long dir c n o f building.