On a Reliability-Based Method to Improve the Seismic Performance of Midrise Steel Moment Resisting Frame Setback Buildings

Abstract

A framework is proposed to improve seismic performance of special steel moment resisting frame (SMRF) setback structures based on the reliability-based approach. In this procedure, seismic design of midrise setback structures is modified to improve the confidence level of meeting the life safety performance level in these structures to a reliable level. To achieve this, based on the results of the incremental dynamic analysis, an algorithm is proposed to introduce more accurate equations to predict the maximum inelastic inter-story drift ratio of setback structures in linear force-based design methods. It is observed that by applying the proposed relations in the seismic design of setback buildings, this type of structures demonstrates more reliable seismic performance compared to the code-designed approach. The proposed method is economically effective in reducing the possible losses during the lifetime of SMRF setback buildings located in seismic prone areas.