Mapping the Seismic Performance of Mid-Rise Steel Frames under Near Field Earthquakes in Tehran Region

One of the most damaging effect of near fault earthquakes is Forward directivity effect which can be witnessed in two Iran’s most catastrophic earthquakes, destroyed Tabas and Bam cities. The same effect is predictable for Tehran metropolis which is surrounded by numerous faults. Regarding the general trend in seismic design codes to accommodate seismic performance concepts in their design methodologies and the lack of regulations considering near field earthquake effects, this study attempts to envelop these topics. A six story steel frame building is designed according to the Iranian Seismic Cod, 2800, and is subjected to near field ground motions by dynamic analyses. The performance of steel frame is categorized to Immediate Occupancy, Life Safety, Collapse Prevention and Destruction level based on FEMA356 performance parameters. Distribution of underlying soil conditions in Tehran and location of seismic faults had great influence on seismic performance of the typical building considered.