seismic collapse risk assessment of a steel mrf considering near-fault directivity effects

In the near-fault regions that forward-directivity effects are observed, ground motion records have high amplitude twosided pulses at the beginning of their velocity time histories. a large velocity pulse can cause significant damages to buildings that lead to increase in the seismic collapse risk of buildings. some research works have focused on seismic collapse assessment of structures under pulse-like near-fault ground motion records (e.g., champion and liel, 2012;yakhchalian et al., 2014, 2019). this study evaluates the forward - directivity effects in near-fault region on the seismic collapse risk of a steel moment resisting frame (mrf). for this purpose, three siteslocated at 5, 10 and 15 km distances from the midpoint of the imperial valley fault line were considered, as shown in figure 1. a 3-story steel mrf was designed according to asce/sei 7-10 (asce, 2010) for thesite with 10 km distance from the midpoint of the fault considered. then, the structure was modeled in opensees (mckenna et al., 2015).