EVALUATION OF THE USE OF CONCENTRIC STEEL BRACING TO IMPROVE SEISMIC PERFORMANCE OF REINFORCED CONCRETE FRAME BUILDING - EQUIVALENT STATIC ANALYSIS

C Preeti, K Jagan Mohan

Abstract: Most of the existing RC frame structures were not designed to withstand seismic effect. To meet those criteria structures should be retrofitted and out of all available retrofitting techniques adding steel braces are considered to be most efficient technique to enhance the seismic performance of the RC frame structure. In the present study three types of buildings are considered i.e., (G+2), (G+5), (G+8) as low rise, medium rise, high rise respectively, and these buildings are assigned by four different types of braces namely X, V, Inverted V, Eccen Forward at the periphery bays of the building in three different pattern i.e., model A, model B and model C. And these buildings are analyzed by nonlinear pushover analysis by using SAP2000.It is observed that the hinges were first formed in beams and followed by columns in bare frame whereas hinges were first formed in braces and followed by columns and followed by beams in case of X, Eccen forward brace and in case of V and inverted V hinges are formed first in brace followed by beams and followed by columns. It is pointed out that RC frames which are assigned with inverted V brace has least shear force and bending moment in the beams when compared to the other brace frames and there is less amount of variations in axial force shear force and bending moment in case of column.

Keywords: equivalent static analysis, steel braces, equivalent strut method

DOI: https://doi.org/10.15623/ijret.2015.0408076