Effect of ‘X’ Type Bracing on Response Modification Factor for R.C. Building with Special Shaped Column Cross Sections

Abstract

Earthquake is the most destructive natural hazard in the world. While designing any earthquake resistant structure, actual forces developed are much higher than designed forces. Therefore, to get design lateral force, the actual base shear force should be reduced by the factor known as response modification factor(R). Response modification factor plays vital role in seismic design of structures. Components of response modification factor (R) are ductility factor, over strength factor, redundancy factor and damping factor. Generally, value of response modification factor is adopted from seismic design codes of developed countries such as Europe, United States and India. Column is important part of Reinforced concrete building as overall load is transferred through column. Not only from aesthetical point of view, but also from structural aspect special shaped columns performs better than rectangular columns. So this study aims at calculating components of response modification factor(R) for column cross section with special shapes (L, T, +) for ‘X’ type bracing. In this study total 16 models of different number of storeys i.e. 5,10 are analysed using Pushover analysis for different seismic zones. The study also involves comparison of response modification factor (R) for structures designed with Indian code IS1893:2016(Part1) and American code ASCE 7-16.