DISPLACEMENT ESTIMATES FOR PERFORMANCE-BASED SEISMIC DESIGN

New analysis and design procedures have been developed for the perform ance-based seismic rehabilitation of buildings. Such procedures requir e accurate estimates to be made of displacements, velocities, and acce lerations. Nonlinear response-history analysis of single-degree-of-fre edom oscillators, having varying values of yield strength and post-yie ld stiffness and using 20 velocity-scaled earthquake ground motions, w as undertaken to verify the accuracy of the proposed displacement-esti mation procedures that make use of relations between inelastic and ela stic displacements. Neat-field earthquake records were not considered. The assumption that mean inelastic displacements are approximately eq ual to mean elastic displacements is reasonable for oscillators with s trength ratios greater than 0.20 and elastic periods greater than the characteristic site period. For other values of the strength ratio and elastic period, the assumption is nonconservative. Mean-plus-one-stan dard-deviation inelastic displacements are approximately equal to 1.5 times mean inelastic displacements for elastic periods greater than 0. 3 s.