Filling and Compacting

The compaction grouting method of sinkhole remediation is commonly employed in areas effected by the downward migration of soil particles. When done properly, compaction grouting accomplishes three goals: the infilling of voids within the limestone, the creation of a cap or seal of the limestone surface and finally, the strengthening of soils weakened by sinkhole activity.

The first step of the process is the placement of 3 inch diameter flush coupled grout casing. GEO-LOGICAL,Inc. accomplishes this by utilizing the rotary wash method of drilling. This is the only method of drilling which allows certainty that the grout point has reached competent limestone. Grout points are typically installed every 8 to 10 feet around the perimeter of a structure and every other point is angled so as to direct grout beneath the interior of the structure.

Once the grout points have been installed, low to moderate slump grout is pumped under constant pressure into the soil. This grout does not mix with the soils in the ground, it pushes them into the surrounding soils, thereby compacting and strengthening loose soils. As the grout is pumped, the grout casing is extracted and pumping pressures are constantly monitored. This method of repair requires that the subject property and any adjacent structures be constantly monitored for movement throughout the pumping process.