Seismic site characteristics for geotechnical engineering purposes: Case study, South of Ras Samadai, Red Sea, Egypt

Abstract

Nowadays, geophysical techniques are widely employed in geotechnical research. Among the techniques that are frequently employed is the Multichannel Analysis of Surface Waves (MASW) technique, it aims to depict spatial differences in physical characteristics of the subsurface layers. The aim of the current research is to produce multiple maps for the seismic site classification (SSC) and dynamic characteristics along the study area located on the Red Sea shoreline of Egypt, south of Ras Samadai. In order to achieve this goal MASW surveys have been conducted in the current study, and corresponding 1D-shear wave velocity profiles have been generated. Consequently, to trace the stiffness change in the subsurface layers, the study provides a series of maps using the shear wave velocity (Vs) values at different depths to help the geotechnical engineers to identify and mitigate the geotechnical potential risk. Additionally, The Vs30 map for the study site is prepared and classified in accordance with the EC8 classification system. Referring to the obtained Vs30 map, the study region is mostly described as category B, with limited zones falling under classes A and C. Moreover, the soil's dynamic properties, including soil amplification and site natural period have already been taken in consideration. Approximately, the whole region exhibits low-to-moderate amplification values. However, two constrained zones are significantly more susceptible to amplification. Furthermore, the studied area is divided into six separate zones according to the obtained isoperiod map. The obtained results could be applied to engineering problems contribute to soil to avoid the probable obstacles during construction on soft soil.