Ground-penetrating radar surveys
Background
Ground-penetrating radar, or GPR, is a non-destructive geophysical technique based on the propagation and reflection of electromagnetic waves with frequencies ranging from 20 MHz to 3 GHz. This technique is sensitive to the properties of the subsurface (permittivity, electrical conductivity and magnetic susceptibility). In particular, it can detect certain cavities, the presence of point reflectors (cables, pipes, etc.), certain interfaces between different layers, as well as defects or variations in the soil structure. However, the processing and interpretation of the measurements remain complex.
Objective
The ISSeP uses this technique to provide insights into a specific question concerning a site’s subsoil. The investigation may, for example, aim to locate the position of a former mine shaft, trace the route of a former mine tunnel or pipeline, or identify anomalies within a defined area.
Implementation
Measurements are taken in the field according to profiles defined on the basis of the area to be examined. They are then processed and interpreted. The results are presented taking into account site conditions and the limitations of the method. Depending on the nature of the ground and the depth being investigated, certain structures may be difficult to distinguish; verification using another method may therefore be necessary.
The ISSeP Subsurface Risks Unit offers this consultancy service on request. A preliminary discussion with the client and the collection of information about the site and the purpose of the investigation are required in order to draw up a quotation.
Contact: meriem.moulana@issep.be