Perryville, MD –
CGS performed compaction grouting for the stabilization of Greenbank Road. Improper placement of backfill from the construction of a sanitary sewer line caused significant on-going settlement of the roadway. The sewer line trench ranged from 15 to 20 feet below the roadway surface. Compaction grouting was determined to be the most reliable method to permanently fix the problem.
CGS and the engineer developed an approach to satisfy the project requirements. After testing soils and base line recording were performed, CGS performed compaction grouting into 800 linear feet of roadway. Three rows of grout injection locations each spaced on a 12 foot grid were created. The placement of injection locations of the center row were staggered. The placement of the locations created a frame around the sewer pipe allowing for the grout to support both sides of the pipe, for the length of the pipe. The grouting was initiated from approx. 18 to 24 inches above the top of the pipe and approximately 18 feet below the ground surface.
There was a total of 199 injection locations and a total volume of 249 cubic yards of grout used. The project was completed in 25 days using two grout crews.