Damages in pavements caused by previous excavation work?

The increasing amount of subsurface infrastructure requires a large number of excavation works on existing roads and pavements. After the completion of such work and the reconditioning of the pavement surface, cracks and other pavement damage can be observed in many cases. A relationship between excavation work and subsequent damages has been suggested. In a study aiming at an evaluation of a possible relationship, GPR data were acquired and analyzed on several roads where excavations had been carried out and where pavement damage had occurred in the vicinity. In many cases it was possible to establish a correlation between subsurface structures obtained by GPR and damages visible on the pavement surface. This paper presents acquisition, processing and interpretation of GPR data together with a statistical analysis of the results. In addition, typical GPR reflection patterns are presented and discussed. The results presented in this paper were obtained in a project supported by the Swiss Federal Roads Office (FEDRO).