Mine Shaft Rehabilitation Grouting-Video

Video Transcription

Video Summary

A contractor repaired water inflow in a historic, timber-lined salt-mine production shaft, originally sunk in the early 1900s. The main problem was an approximately 11-gallon-per-minute inflow through a discontinuity in sandstone about 1,100 feet below ground. Moisture was causing salt buildup on the timber, creating operational and safety risks.<br /><br />Working from inside the shaft, the team installed and pressure-tested two rings of standpipes, then drilled injection holes. They first used water-reactive polyurethane to seal near the shaft and ultrafine cement grout to extend the treatment. When the cement grout failed to connect reliably with the water-bearing feature, they reassessed the approach and switched to low-viscosity acrylate resin. Additional holes and controlled gelation allowed them to seal the feature and eliminate its inflow. About 20 gallons per minute of diffuse water remained elsewhere in the shaft. The project took five weeks, including three weeks of shaft work.

Keywords

salt mine shaft repair

water inflow control

polyurethane grout

acrylate resin sealing

timber-lined shaft