Evaluation of Seismic Hazard of Hpp Ashta, Albania

Based on the objectives for the evaluation of HPP Ashta seismic hazard, the purpose of study should comprehend: a) Peak Ground Acceleration (PGA) and Spectral Acceleration (SA) values on rock site conditions for a return period of 475 years (this equates to a 10% probability of a value being exceeded in a 50 year period) for all three sites under investigation, using Cornell-McGuire Probabilistic Seismic Hazard Assessment (PSHA) methodology. b) Peak Ground Acceleration (PGA) and Spectral Acceleration (SA) values on specific site conditions, based on the data of geotechnical profile, Vs30, and SPT-N, using soil correction factors of the National Earthquake Hazard Reduction Programme. c) Peak Ground Velocity (PGV) values on rock and specific site conditions, for all three specified sites under investigation. It is important for such kind of critical structures, as HPP Ashta is, to estimate the greatest possible seismic hazard, based on fault types, which are the source sites of earthquake generation in or near the area under study. The extensional region, into which the normal faulting earthquakes are generated, is located in eastern Albania. The compression region, into which mainly thrust faulting and much rare strike-slip faulting earthquakes are generated, is located in western part of it.