Soil Characterization of Jeddah City, Saudi Arabia

Abstract

Summary 75 of geotechnical boreholes have been conducted in Jeddah City to identify the soil characteristics and their geotechnical parameters. The depth of boreholes extends up to 40 meters in some sites. The standard Penetration Test (SPT) was assigned at each 1.5 m depth interval. Water table fluctuated between 0.5m to 9m below the ground level. In this study, 75 one-dimensional (1-D) MASW survey has been carried out and respective velocity profiles are obtained. Number of 2-D MASW profiles has been carried out through multiple shot gathers in a consecutive way along the survey line moving both source simultaneously by fixed distance after each shot. Shear velocity 1-D and 2-D profiles have been processed using surfseis software. The shear wave Velocity calculated at the mid-point of each survey line is comparable with the borehole location because the survey line mid-point is coinciding with the borehole location. The average shear wave velocity values up to 30m depth obtained from survey has been used to construct the Vs(30) map for Jeddah city According to Vs(30) values, the soil classes for Jeddah City are classified into three classes as “site class D”, and “site class C” and “site class B”.