Using Ground Penetrating Radar for Assessing Highway Pavement Thickness

摘要

Surface distress is a fairly good indicator or rehabilitation needs but it does not directly relate to remaining life estimates. Mechanistic pavement design requires that strains be calculated utilizing more or less complex modeling. Over the years many devices measuring surface defections under a given load have been developed. the device by choice for assessing strains due to load is the failling weight defiectometer (FWD). It creates an impulse load on the pavement surface. the data are commonly used in models for backcalculation of elastic moduli and strains. More complex modeling would involve finite element or dynamic element methods. The FWD method has proven to be an excellent tool for overlay design. For this purpose its simplicity and straightforwardness are well documented. However, to successfully backalculate layer stiffness adequate layer thckness is needed. Thus there is a strong need for assessing layer data at testing points. Using Ground Penetrating Radar (GPR) it is possible to achieve data without coring. The present paper is a part of an ongoing bearing capacity study carried out by a regional road administration in central Sweden. Its objective is to optimize testing for equipmet and methods used and presently available. In addition to evaluate the results from the study, the present paper discusses some other applications for GPR that may evolve from it.