Predictive mapping of soil geophysical properties for GPR utility location surveys

Ground Penetrating Radar (GPR) offers a relatively rapid and non-intrusive method for detecting buried utilities. In congested urban environments, where most buried utilities are to be found, this translates into significantly reduced disruption to highway users and reduced risk for developers and contractors. However, GPR performance varies significantly over large geographical areas due to variations in soil type and water content. Therefore, GPR utility location can be perceived by clients as largely hit-and-miss in terms of its planning, as full information may not be known in advance for determination of expected penetration depths and the most appropriate signal frequency ranges. This paper details the current state of predictive soil electromagnetic property mapping, from which it will be concluded that existing geotechnical databases and techniques can provide useful data on which to base such maps. In so doing, it also extends knowledge on the efficacy of predictive mapping for potential use internationally.