seismic response evaluation of setback steel frames subjected to near-fault pulse-like ground motions

In this paper, attempts are made to evaluate the effects of the extracted pulses and the residual components of near-fault (nf) pulse-like ground motions on seismic response of setback structures. to this end, nine ten-story steel frames with one-side setbacks are subjected to 55 nf ground shakings and their corresponding components. the effect of the ratio of pulse period to the fundamental period of the structure (tp/t1) is also investigated through conducting incremental dynamic analyses. the results are compared in three hazard levels, namely, obe, dbe, and mce. it is concluded that the relative effect of pulse and residual components of nf records depends on the intensity level as well as the ratio of tp to t1. in the obe hazard level of the studied structures, when tp/t1 is about 0.5, the structural responses are more affected by pulse records, while in the case that tp/t1 is not less than 1, the residual component plays an important role in seismic responses. however, in dbe and mce hazard levels, when tp/t1 is not about 1, the relative effect of pulse components is greater than the residual records in most of the studied setback frames.