Seismic Response of Steel Structure with Mega Bracing System

Abstract

In General, the structure in high seismic areas may be susceptible to the severe damage. Along with gravity load structure has to withstand the lateral load which can develop high stresses. Now a day, shear wall in R.C. structure and steel bracings in steel structure are most popular system to resist lateral load due to earthquake, wind, blast etc. The bracing is one of the best lateral load resisting systems and it will be the viable solution for enhancing earthquake resistance. A Bracing is a system that is provided to minimize the lateral deflection of structure. The members of a braced frame are subjected to tension and compression, so that they are provided to take these forces similar to a truss. Braced frames are always designed of steel members. Use of the braced frames has become very popular in high rise structure and also in seismic design of them. So there is a need of precise and exact modeling and analysis using software ETABS to interpret relation between brace frame and without brace frame aspects. The present study assesses the seismic response of steel structure with concentric bracing system. Two structural configurations were utilized; vertical irregular model (VIRM), vertical irregular model with mega bracing (VIRM_MB). A 15 storey steel moment resisting frame was analyzed for all zones of soil type-II (medium). The analyses were carried out to assess the structural performance under earthquake ground motions. These models are compared in different aspects such as storey drift, storey displacement and base shear.