Abstract :
The combined use of a Ground Penetrating Radar (GPR) and conventional techniques (e.g. drilling and sampling) allow a comprehensive, time-saving and cost- effective investigation of potential contaminated subsoil at industrial sites such as oil storage terminals, refineries or service station sites. The georadar not only provides a three-dimensional image of the subsoil, indicating lithological and hydrological features such as different soil layers, the extend of landfills and the groundwater table, but also objects like underground installations (e.g. pipe networks and tanks), foundations, warfare agents and cavities. Moreover, highly contaminated areas can be visualized by this system under specific conditions. Based upon the geophysical data, selected borings can be placed with high precision within the identified critical areas. The borings allow a recalibration of the geophysical data as well as the collection of soil and water samples for geochemical analyses. Contrarily, the GPR allows the completion of lacking data between the already existing borings without additional openings. The application of this combination not only enhances the decision quality of the results, but it also gives data sets, which are more representative and cost-effective. The successful application, but also the geophysical and lithological requirements and limits of the method, are demonstrated with selected examples of investigation projects, which have been carried out by BGI recently.
