Potential Use of Ground Penetrating Radar in Highway Rock Cut Stability

Highway rock cuts typically fail along pre-existing discontinuities, and are triggered either by seismic activity, high groundwater pressures, ice wedging, or progressive deterioration of the intact rock because of weathering. Remediation and/or damage mitigation is required for all road cuts that threaten the lives and property of the motoring public. Analysis of potential instability can range from limiting equilibrium analysis to on-site engineering judgment of an experienced specialist. Rock determined to be loose with the potential for failure must be removed or restrained in some way. In any case, the mapping of discontinuity orientations is a requirement. Most discontinuities can be identified once the cut has been exposed. Horizontal to sub-vertical discontinuities will intersect the exposed face and can be projected back into rock mass, and an appropriate analysis can be undertaken. Vertical discontinuities however, striking parallel to the road cut cannot be seen, because they do not daylight into the cut. Ground Penetrating Radar (GPR) has the ability to detect these vertical discontinuities and can be used to identify slopes at risk, avoid failures, reduce property damage and avoid injury and lost of lives