GPR INSPECTION OF A MOUNTAIN MOTORWAY IN SWITZERLAND

A radar survey was carried out to support the planning of maintenance work on Switzerland's Gotthard Motorway. This work became necessary af ter damaged pavement layers had been detected by visual inspection and coring. Radar data acquisition, processing and interpretation focused on the investigation of pavement damage. However, additional informat ion such as layer thicknesses and the position of the rock surface cou ld be extracted from the acquired dataset. Results of the radar survey were verified by local coring and during repair work. The radar surve y proved to be a useful complement to traditional pavement monitoring methods providing not only quasi-continuous information between boreho les but also locating previously unknown problem zones. The comparison between datasets that were acquired before and after the maintenance work suggests the success of the repair work and the suitability of GP R as a quality control tool. (C) 1998 Elsevier Science B.V. All rights reserved.