The inspection of large retaining walls using GPR

In hilly regions, retaining walls along roads and motorways are numerous. In some cases the knowledge of the details of the construction is limited. If rehabilitation work becomes necessary, a detailed knowledge of all details of the construction is desirable for an improved planning In a pilot study a GPR inspection of retaining walls was carried out. This included the development of an apparatus for the controlled positioning of the radar antennas on the faces of the walls as well as an evaluation of different antennas and acquisition parameters for this application. This paper describes the approach for data acquisition, acquisition and processing parameters and the results obtained on a retaining wall situated at a Swiss motorway.