Differential weathering of shale and sandstone seams near a tunnel portal caused toppling of rocks into existing slide fences. To ensure that the track was safely operable and to limit the amount of track closures and cleanup time, the railway contacted GeoStabilization International®’s Rockfall Division to develop a plan for mitigation. Rock bolting and draped mesh options were considered, but due to the large area and mode of failure GeoStabilization’s team developed a low-cost scaling program that would prevent much of any future rockfall. Using their specialized tools, highrail trucks, and airbags, large amounts of unstable rock were dropped onto the track, which was protected from falling debris using blast mats. We completed the challenging project on-time and on-budget despite very narrow track availability windows.*
*GeoStabilization does not offer structural engineering services in Illinois. However, we do contract with licensed structural engineering companies to provide these services to our clients throughout the state.
A variation of karst sinkhole grouting is the grouting of mined coal seams and workings located below existing infrastructure that exhibit the potential to propagate to the surface and cause sinkholes and/or subsidence.