Integration of Geophysical and Geotechnical Techniques to Identify Distress Underground Conditions (Case Study)

Several roads and buildings in ABU DHABI mainland area were subjected to sever damages in the form of cracking, subsidence and settlement,(Fig. 1) as a result of the adverse subsurface conditions. It is necessary to investigate the depth and lateral extent of these adverse strata before any maintenance or rebuilt operations can be carried out .This requires a considerable amount of investigation into foundation conditions at the proposed sites, by examining materials taken from various depths at a number of discrete points over the site (Clayton et.al., 1995). As the number of boreholes and trial pits increases, the cost of investigation becomes prohibitive and the period to accomplish the work becomes very lengthy. This is an important consideration when investigating localized features such as cavities, weak and contaminated zones, or where detailed subsurface profiles are required. These problems have led to the use of geophysical, non-destructive techniques integrated with geotechnical techniques for site investigations to optimize the identification and location of problematic underground conditions promoting distress. In this study the recent geophysical techniques used in civil engineering investigations and their integration into the overall geotechnical information in relation to detailed design, Road & Building construction, are discussed and illustrated with a case study.