Retrofit Residential Building by Steel X Bracing According to BNBC 2020

Abstract

Earthquake is a curse of a developing country like Bangladesh, so developing country needs to be ready to resist this kind of hazardous. For this reason we need to study how to increase stiffness of the structure. So we choose Finite Element package ETABS to conduct this study. We also select updated national building code and follow the guideline to simulate analysis. Arbitrary a residential building was selected for this study, which is situated in savar, Dhaka. This building standing on zone-2 according to BNBC 2020, but same structure also simulate remaining 3 difference zone also. Retrofitting is one of the methods to strengthening the structure against earthquake force. In this study we use steel bracing retrofitting method and try to estimate 16 different bracing conditions against earthquake force. Finally we use 300 mm x 300 mm cross sectional size bracing with 13 mm, 16 mm, 18 mm and 25 mm thickness. But the use maximum size of bracing we are able to bring the displacement ratio of the response spectrum to 1.24 from 1.39 at no bracing condition. Although this was not good enough, but finally we were able to mostly reduce the displacement ratio for the response spectrum force.