Ultrasonic Method as a Tool for Geotechnical Parameters Estimation at Proposed Engineering Site/Western Iraq

The objective of the present research is to confirm the possibility of ultrasonic methods as geophysical tool for the estimating of geotechnical parameters for engineering purposes. Thirty seven (37) rock samples were collected at different depths of borehole drilled at the study area, and both primary and secondary waves velocity (Vp and Vs) were measured in laboratory. To evaluate the rock competence as foundation material for engineering works, some important geotechnical parameters including Poisson’s ratio(σ), Stress Ratio(Si), Material index(Im), Concentration index(Ic), and Density gradient( Di) were calculated. The obtained results demonstrate that the first surface layer is characterized by incompetent to fairly competent materials, the second layer (Anah Formation) is characterized by alternation of the moderately competent ( limestone) with thin incompetent (coralline limestone) layer, while the third layer (Baba Formation ) which composed of dolamatic limestone is characterized by good geotechnical parameters, reflect good competent rocks representing more suitable rocks as foundation layer for civil engineering constructions at the investigated site. The results also confirm the efficiency of ultrasonic method in estimating and assessing the geotechnical parameters of rock samples in pre-construction studies.