COMPARISON OF PERFORMANCE EVALUATION CONCEPT FOR RC BUILDINGS CONSIDERING TURKISH EARTHQUAKE CODE AND THE PROPOSED EMPIRICAL RELATION

摘要

This paper shows the adequacy of proposed empirical relations for estimating the inelastic deformation demands of existing structures and the performance displacement obtained by applying nonlinear static procedures as defined in the Turkish Earthquake Resistant Design Code-2007. As widely preferred by engineering applications currently, structural performances of existing reinforced-concrete (RC) buildings are determined by computations based on nonlinear static analysis, in other words pushover analysis, as defined in many codes and standards. Since the application of nonlinear static procedures are limited depending on the number of stories,mass participation ratio, vertical or in-plan irregularities, recent studies are concentrated on establishing relationships for estimating inelastic deformation ratios and seismic capacity-demand index relationships,considering an equivalent single-degree-of-freedom (SDOF) system and realizing nonlinear dynamic analysis.Recently, our research team proposed an empirical relation for estimating the inelastic deformation demand, CR,of existing structures, considering the stiffness-degrading nonlinear behavior of structural elements. For this purpose, sets of Turkish recorded earthquake motions are selected and nonlinear dynamic analyses are performed for equivalent SDOF systems having a wide period (Tn) range, consistent with other researchers' work, are taken into account. Assuming 8 different levels of yield strength reduction factor, Ry, and five strain hardening, α, a number of 214,400 runs of analysis is realized and an empirical expression is established employing Tn; α and Ry. Finally, 8 existing RC buildings are investigated in details and later performance displacements are calculated by applying the nonlinear static procedure as in TERDC-2007. Results are successfully compared with the inelastic displacement demands computed by the proposed empirical equation.