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.
The US Army Corps of Engineers made a rock cut during the road construction for the Eastman Lake Park headquarters office access road in the early 1970’s.