vulnerability assessment of a3-storysteel braced frame with khorjiniconnections and infills in tehran

connection failure of extremely large number of steel buildings with semi-rigid "khorjini" connections has been reported in past major earthquakes in iran (i.e. bam-2003 and manjil-1990). in the present paper,atypical 3-story steel braced-frame building with “khorjini” connections with infill wall is selected and the incremental dynamic analysis (ida) is performed to investigate its seismic performance.the probability of exceeding desired performance limits on future probable earthquakes in tehran are estimated for tehran. in order to develop such fragility curves, 44 records as offered by atc-63 are adjusted for the study area and used to perform nonlinear analyses. ida-generated fragility curves are presented forimmediate occupancy (io), life safety (ls) and collapse prevention (cp) limit states performance. the results showed 56% probability of exceeding the cp performance level for earthquakes with a return period of 2475 years. for return period of 475 years, this valuewas16%..