Appraisal of Seismic Design Approaches Amelioration of DDBD for RC Framed Structures

Abstract

newline ABSTRACT newlineThe force-based design (FBD) approach is prevalent in most of the national seismic design newlinecodes. However, several limitations of the force-based design in achieving the requisite newlinestructural performance have surfaced during past seismic events. This emphasised the need newlinefor a robust performance-based seismic design approach that shall be capable to achieve newlinethe desired structure performance for anticipated seismic hazard. Further, under the newlineperformance-based seismic design (PBSD) framework, there is a greater demand for a newlinethorough yet simple design procedure. Direct displacement-based design (DDBD) and newlineenergy-based design (EBD) approaches are relatively new seismic design methods in the newlinecontext of PBSD that claim to be more rational and predictive than the FBD. The force, newlinedisplacement, and energy-based approaches are the three conceptually distinct design newlineapproaches that impart different strengths, stiffness, and ductility properties to a given newlinestructural configuration and hazard. Further, it is also of interest to compare these newlineapproaches in order to assess their relative merits in achieving the desired structural newlineperformance level vis-á-vis the ease of applying the approach and economical design. In newlinethe present study, the behavioural assessment of a six-storey RC building frame designed newlineusing FBD, DDBD and EBD approaches has been carried out. The comparative study of newlinevarious design parameters shows considerable difference in lateral storey forces newlinedistribution and reinforcement design. Furthermore, nonlinear static and dynamic analysis newlineresults show that in the FBD frame plastic deformation is concentrated in the lower storeys. newlineOn the other hand, in EBD frame large plastic deformation is concentrated at the middle newlinestoreys though the inelastic hinges are well distributed over the height. In the DDBD newlineframe, the inelastic hinges and plastic deformations are approximately uniform over the newlineheight. Overall, the six-story frame designed using the DDBD approach seems more newlinerational