سید رضا منصوری

In this thesis, probabilistic approach have been used to analyze the seismic hazard of Birjand. Birjand and a region within a radius of 150km around has been selected for this case study. South Khorasan province, with provincial capital of Birjand, is located in wide extent at the eastern part of Iran. Various striking fault zones in the eastern part of Iran has resulted in high active seismic regions. Identifying the active faults, which are covered by new quaternary sediment and have not any sign, are important in seismotectonic assessment of this region. In this thesis, basement faults in the studied area are identified and mapped. The aeromagnetic data of the area are discussed and magnetic lineaments with the proper filters are obtained using appropriate filters. Finally, the maps of total magnetic field are prepared and on the basis of them, 17 hidden faults are detected in the studied area. The parameters of seismicity in the studied area has been calculated using the algorithm of Kijko(1994). The reduction and weakening rate of parameters of ground motion have been predicted using Campbell-Bozorgnia(2008) equation. Then the seismic hazard analysis has been done using the EZ-FRISK software. The results has been calculated in two stages, first calculation of the maximum acceleration caused by activities of reveal seismic sources and then the maximum ground acceleration considering activities of the reveal and hidden sources. Based on the results, Birjand is subjected to horizontal acceleration of 0.39 of Earth's gravity which according to the Standard letter 2800, design of buildings against earthquake, risk zoning of the city is very high. After identifying hidden faults, acceleration of Boshruyeh increased from 0.08g to 0.35g and Dehsalm from 0.12g to 0.4g. Based on these results, Boshruyeh and Dehsalam are located in very high risk zoning. Regarding identified hidden faults, the acceleration of Asadabad increased from 0.28g to 0.35g and risk zoning of this