Just east of Northern California’s famous wine country, the Calpine Corporation operates a state of the art, eco-friendly geothermal power generation plant. This facility covers thousands of acres and depends on a network of rugged mountain roads for maintenance, new construction, and general operations. The plant property is accessed from the west by Geysers Road and from the east by Socrates Mine Road.
Calpine contracted GeoStabilization International® to repair a section of Socrates Mine Road that was subjected to a shoulder-damaging slip out. In addition to the damaged shoulder, the over-steep head scarp, left behind by the slip, threatened the stability of the road. Calpine not only required a economical fix; they also wanted GSI® to keep the road open during the repair and build an over-wide shoulder to accept future pipeline supports.
GeoStabilization International®’s remediation design included a combination of SuperNails®, Reticulated SuperMicropiles®, and an innovative Geosynthetically Confined Soil (GCS®) retaining wall for the purpose of widening the shoulder. Calpine reported that the site was successfully repaired for less than half the cost of traditional repair techniques.
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.