Evaluation of Geotechnical Characteristics of Soils through Seismic Surface Waves for the “Ashta Hpp”, Albania

The seismic refracted method has been used extensively around the world for geological and geotechnical investigations for hydro power projects, etc. Due to the seismic parameters measured in the field and according to the borehole log for all drilling, the Ashta area sites are classified to rock Ashta2 and to stiff soil Ashta1 which are taken into account for the re-evaluation of seismic hazard. Using the multi-channel analysis of surface waves MASW apply through the "SURFSEIS" method have taken the vertical profile of shear waves velocities. A summary of the profile velocities Vp and Vs estimated from seismic refraction measurements and the method of surface waves “MASW” performed in Ashta2 site are shown. Based on the provided Vs30 and SPT-N data, the specific site conditions according to International Building Code, for the sites under investigations are classified as follows: HPP Ashta 1 site to C site class (i.e. very dense soil and soft rock site), HPP Ashta 2 site to B site class (i.e. rock site). The results of seismic hazard for HPP Ashta sites on their specific site conditions at probability 10%/50 years are taken into consideration for HPP Ashta site design.