EVALUATION OF NONLINEAR STATIC PROCEDURES IN THE SEISMIC DESIGN OF REINFORCED CONCRETE BUILDINGS

Application of performance based engineering concepts in seismic design is achieved only by introducing nonlinear analysis into seismic design methodology. Furthermore, the identification of sources of inelastic energy dissipation and quantification of the energy absorption capacity to reduce the elastic forces for seismic design call for nonlinear analysis. The nonlinear analysis can be done either by Nonlinear Static Procedure (NSP) or by Nonlinear Dynamic Procedure (NDP). The NDP requires considerable judgement and experience to perform whereas, the NSP, also called “Pushover Analysis,” uses simplified nonlinear techniques to estimate seismic structural deformations. Performance points and target displacements from the NSP were compared with the maximum roof displacements of NDA for the various ground motions intensities of probabilities of exceedance of 2% in 50 years and 10% in 50 years at Los Angeles and Seattle. The comparison is also made for the seismic zones IV and V of IS: 1893-2002 by considering the Indian Standard Response Spectrum compatible ground motion.