Applicability of Radar Subsurface Profiling in Estimating Sidewalk Undermining

An evaluation was made of the applicability of the geophysical technique of radar subsurface profiling to estimating the extent of sidewalk undermining. It was found that there is a distinct difference between the observed radar echo patterns of a nonundermined sidewalk and those from an undermined sidewalk. Therefore, it is feasible to determine from the radar scan of a sidewalk the length of the sidewalk that is undermined. It is also feasible to determine the approximate depth of voids underneath an undermined sidewalk; however, this may sometimes be difficult to achieve. The approximate cost of surveying a sidewalk with the technique was also estimated.