Valley Creek Sewer Tunnel Project Soil Stabilization by Compaction Grouting Bessemer, Alabama Back to Project List Limited Mobility Grouting Compaction grouting is used to stabilize karstic geology soils in advance of tunneling operations. Project Overview: Layne GeoConstruction designed and constructed a soil stabilization program in karstic geology along the alignment of a 10,000 linear foot, 16-foot diameter bored tunnel, at 65 feet below ground surface level. Initial attempts by the general contractor to advance the tunnel with the tunnel boring machine were marginally successful in the difficult subsurface conditions parallel to Valley Creek. Subsequent to the placement of a low slump compaction grout, tunnel production rates increased dramatically. The compaction grouting process yielded a 500 psi soil block throughout and beyond the tunnel zone. The grouting virtually eliminated groundwater inflow from the adjacent stream, and immobilized the large boulders which were present within the tunnel area. Layne also designed and installed a drilled micropile support system near a large concrete junction box and 72-inch live sewer force main, to protect the utility as the tunneling operations advanced.     Value of Work Performed: $4,300,000 Project Duration: 15 months Project Completion Date: November 2004 Project Reference: Construction Manager: Hailey / Rast, JV Micheal Morris (205) 425-3272