KANE GeoTech, Inc. - A leader in geotechnical engineering.
Ground Deformation Monitoring
Location:
Dana Point, California
Timeframe:
January 2003
Client:
South Coast Water District, Laguna Beach, California
Description:
Compaction grouting operations by
Hayward Baker, San Diego, California adjacent to a municipal well
required that a real time monitoring system be installed. The system was to
be monitored along the length of the well casing to evaluate possible
horizontal casing deflections during grouting.
Time domain reflectometry (TDR) was chosen as the best choice for such monitoring. Three TDR sensor cables were installed in vertical boreholes around the circumference of the well casing to a depth of 30-ft. The grouting operation in each hole began at a depth of 25-ft and progressed to within 10-ft of the surface. Cables were monitored sequentially for deformation during grouting operations using a TDR cable tester and laptop computer. In one instance the system successfully detected abnormally high soil pressures and grouting operations were paused to allow pressure to return to acceptable levels. The grouting was carried out successfully with no damage to the well.
Time domain reflectometry (TDR) was chosen as the best choice for such monitoring. Three TDR sensor cables were installed in vertical boreholes around the circumference of the well casing to a depth of 30-ft. The grouting operation in each hole began at a depth of 25-ft and progressed to within 10-ft of the surface. Cables were monitored sequentially for deformation during grouting operations using a TDR cable tester and laptop computer. In one instance the system successfully detected abnormally high soil pressures and grouting operations were paused to allow pressure to return to acceptable levels. The grouting was carried out successfully with no damage to the well.
