Seismic Performance Assessment of Semi-rigid Frames for Different Performance Criteria

Evaluation of the performance of semi-rigid (SR) frames for different types of earthquakes is a topical subject of research. In this paper, the seismic performance of SR frames is evaluated using the capacity spectrum method. One five-story rigid frame is analyzed in order to compare the relative performance with the semi-rigid frames. An ensemble of ten far-field earthquake ground motions is selected for determining the statistics related to the probability of exceedance (POE) of the performance criteria. The performance criterion for each seismic demand parameter (SDPs) is selected based on the engineering judgment. Assuming earthquake variability as a major source of uncertainty, the POE of the performance criterion of a seismic demand parameter is determined for each PGA level of the earthquake following a lognormal distribution. The SDPs, namely, the maximum inter-story drift ratio and maximum roof drift ratio at the performance point are obtained for a particular PGA. The results of the study indicate that the POE of the performance criterion considerably differs with the seismic demand parameter and the nature of the earthquake. Further, the POE values considerably vary with the stiffness parameter.