Integrated Geophysical Investigation at a Construction Site in a Highly Urbanised Area

Techniques to investigate the shallow underground with the help of a combination of several geophysical methods increased rapidly during the last decade. Nevertheless, the use of different geophysical methods results often in different interpretations of the investigated area. This paper deals with the integrated interpretation of CMP-refraction seismic, refraction tomography, traditional refraction seismic, electric resistivity tomography and borehole logging data acquired at a construction site in a highly urbanized area (Makkah, Saudi Arabia). Objectives of the geophysical measurements were mainly to determine und characterise the thickness of the saturated zone, the depth of the groundwater as well as the depth of the bedrock. All geophysical results (seismic tomography, resistivity and borehole logs) are combined and joint interpreted together with the data from the given boreholes in order to calibrate the final interpretation result. Interpretation has been performed with the state of the art interpretation and modelling software PETREL (Schlumberger Information Solutions) according to international industry standards. The chosen interpretation system ensures the generation of exact and consistent spatial images of the underground conditions.