The number of project has been failures and increasing recently due to weak zones in the building's foundation and rocks. So, Geophysical investigations related to the site foundations before the construction stage are vital to avoid the danger of future collapse of engineering structures. Therefore, it was decided to inspect the location of one of the proposed engineering sites by achieving the seismic refraction surveying with the aim of detecting the possible weakness zones for the site foundation rocks. A Geode instrument is used to acquire data which then surveying data acquisition was achieved for parallel traverses with 4m spacing between each one. Thus, 10 lines with a length of 115 m each were taken with a geophone spacing of 5 m apart. Then, the data is processed with Pickwin software, which is used to pick and denoise data. After that, the initial model was created with Plotrefa software and the inversion was converted to a layer model. Then, a 3D model of the studied site is created by using Zond software. Finally, the velocity model of the study site was built for both Vp and Vs results. As a result, three different layers with velocity values ranging between 300-4000 m/s, thicknesses of 8, 6 and 16 m belong to the top soil, weathered layer and Tanjero Formation of sandstone or marl were determined. Many Faults were identified as structures affecting the project construction which appearing in all studied profiles, located at a distance of 60 m and at depths ranging from 8 to 14 m in a northwesterly direction. Petrophysical, geotechnical, and elastic parameters were calculated from the Vp and Vs data. Finally, the studied layers were found to be weak, incompetent or fairly competent.
Othman et al. (Tue,) studied this question.