Seismic risk analysis of concrete moment-resisting frames against near-fault earthquakes

Abstract

Characteristics of earthquake strong ground motions play an important role in the calculation of seismic-induced risk imposed on the structures. Distinguished features exist in movements recorded near seismic sources, as a result of a substantial amount of energy in a short period of record arrival time. In this article, seismic risk analysis of concrete moment-resisting frames due to near-fault strong ground motion is calculated and compared with that of caused by far-field strong ground motions. To achieve this goal, three moment-resisting frames with 4, 6, and 10 stories were designed based on international seismic design code. These frames are modeled applying modified Ibarra–Krawinkler moment–rotation nonlinear model in which strength and stiffness deterioration are involved. Seismic risk analysis of the frames is implemented using the Pacific Earthquake Engineering Research Center approach. Through this approach, probabilistic seismic hazard, probabilistic structural demand, probabilistic structural damage, and probabilistic loss curves are combined. Mean annual frequency of exceedance of seismic-induced losses presents probabilistic seismic risk of the sampled frames. According to the achieved results, the four-story frame (representative of low-rise frames) is more prone to be affected by near-fault strong ground motions in view of calculated seismic-induced risks.