Geotechnical Site Characterization Using Seismic Refraction Method at Babylon University Campus, Center of Iraq

The current study aims to evaluate the geotechnical parameters required for engineering construction. For this purpose, four seismic refraction profiles were implemented at the College of Science site (a building attached to the deanship) at the University of Babylon, south of Baghdad Governorate, to describe the geotechnical parameters of the soil. Both compressional (P) and shear (S) waves were detected, processed, and interpreted. Many important geotechnical parameters were calculated depending on the values of seismic wave velocities (Vp and Vs.). These parameters consist of Poisson's ratio (σ), Material index (Im), Stress ratio (Si), N value, and Ultimate Bearing Capacity. Based on the results of the velocity measurements, available information, and geotechnical evaluation, the layers in the study area were classified into two main layers. The surface layer corresponds to recent sediments of fine, dry-fill material or silty clay with a small amount of sand. It is characterized by slightly poor soil quality and is good for very light structures with suitable methods. The depth of the first layer is about two meters. Comprising the second layer is medium-density silty sandy clay, characterized by a fairly to moderately efficient material and suitable for buildings with low to moderate loads. Finally, the outcomes of the current study revealed the efficiency of the seismic refraction method as a complementary technique for characterizing engineering sites.