Seismic hazard analysis and uncertainty of Kahrizak, South Rey and North Rey faults

The main purpose of seismic hazard analysis is to estimate the seismic loading parameters more accurately to optimize the seismic design of the structures and their costs. Kahrizak, South Rey and North Rey faults are located in the south of Tehran and some discussions have been raised about their presence. In this paper, after reviewing the discussions about the presence or absence of the mentioned structures, their effect on the peak ground acceleration is investigated in the Tehran area. The results show that considering these faults in the analysis, increases PGA values up to 100% at a great part of the study area in the south of Tehran. In addition to the variation of the PGA values, the design earthquake characteristics (in terms of the magnitude and the source to site distance) also differ substantially between the two cases of the presence and absence of the mentioned structures. Based on these results and considering the dramatic effects of uncertainties of south Tehran faults on seismic hazard parameters in the region, further studies on the presence or absence of these faults are necessary.