Locate voids and potential sinkholes up to 30ft deep with a void survey. Typical subsurface voids are caused by hydrogeological and geochemical processes, unstable subgrades, flooding or defective utilities.
Areas showing surface signs of subsidence such as cracks or depressions could be harbouring subsurface voids below. GPR presents a fast and effective way of identifying shallow voids in a non destructive manner. The difference in electrical properties between air (i.e. a void space) and the surrounding subgrade, soils or concrete provides a clear contrast in radar imaging and therefore relatively straightforward interpretation.
Twinning this method, where appropriate, with ground resistivity and/or electromagnetic profiling widens the understanding of a suspected void site and can give insight into how and why voids may have developed – vital information for planning effective mitigation and longer term repairs.