Tunnel 3D Scanning and Remediation

As part of its IDIQ contract with Region One of the Forest Service, AESI, in conjunction with Shannon & Wilson, conducted tunnel inspections and provided recommendations in the Idaho Panhandle and Lolo National Forests. AESI performed ground-based LiDAR 3D scanning on the tunnel’s interiors as part of the inspections. The goal of the project was to improve tunnel stability and reduce rockfall hazard related to kinematically admissible rock wedges exposed in the tunnel crown and sidewalls. Point clouds generated from the 3D scan data were used to observe tunnel conditions, progression of cracks, loose rock mass conditions, and any other signs of deterioration or distress. The scan data was processed in Autodesk ReCAP Pro and Autodesk Civil 3D to help develop construction plan sheets and specifications for the remediation of the tunnels. Cross-sectional slices were cut through the tunnel point clouds at specific tunnel stations to help create typical details for the grouted rock dowel reinforcement improvements.