Study on seismic damage of SRHSC frame columns

Abstract

The damage evolution in steel reinforced high strength concrete (SRHSC) frame columns was studied based on the test results of cyclic reversed loading experiment of 12 frame column specimens with various axial compression rations, stirrups ratios, steel rations and loading histories. The variation law of the ultimate bearing capacity, ultimate deformation and ultimate hysteretic energy dissipation of specimens under different loading protocols was obtained. The seismic damage characteristics, as well as strength and stiffness degradation, of SRHSC frame columns were analyzed. Based on the analysis of the nonlinear double parameters combination of deformation and energy, a damage model that can well reflect the mechanical characteristics of members subjected to a horizontal earthquake action was established by considering the effects of the number of the loading cycles on the ultimate resistance capacity (ultimate deformation and ultimate energy dissipation capacity) of members, and the loading history on damage, etc. According to the test results, the related parameters of the damage model were proposed. Finally, the damage model proposed was validated by the test results. Results indicated that the proposed damage model is theoretically more reasonable and can accurately describe the seismic damage evolution of the SRHSC frame columns. The results also can be used as a new theoretic reference for the establishment of damage-based earthquake-resistant design method of SRHSC members.