Compaction grouting is a method of soil stabilization where a low flow cementitious grout is injected into the soil to form a grout bulb. The grout does not permeate soil pores, but displaces the soil and compacts it in the process.
The compaction grouting process is typically carried out in vertical stages, progressing upwards from the deepest unstable zone. In shallow fills the upper zone may require grouting initially to densify the upper layer and also increase the overburden pressure.
This grouting application is most suitable in stabilizing areas of low density fills, since the maximum effect is realized in the least stable zone.
Geo Grout has applied compaction grouting techniques to stabilize low density fills on high maintenance roadways.
Consolidation grouting is a method of soil stabilization where a high flow, fine to micro fine cementitious grout, is injected into the soil. Permeation of the grout into the soil fills available air voids, increasing soil cohesion. Such a method of soil stabilization is particularly applicable in trench cuts through granular subsoils.
Curtain Grouting, essentially a form of Consolidation grouting, is a procedure primarily used to control seepage on dam and canal projects by sealing off fissures in bedrock, granular soil pockets and minor cavities. This process involves grouting a line or several lines of holes in stages along the water cutoff zone and requires specialized instrumentation to monitor grout pressure and flow parameters.
In areas of deep trench settlement, a roadway is typically maintained with periodic asphalt patch overlay until no further settlements are evident. This may extend over a number of years resulting in ongoing hazardous conditions, as well as traffic interruption during the maintenance period. By utilizing compaction grouting techniques, the trench fill zone is stabilized, reducing the potential for continued settlement and hazardous conditions. This form of soil stabilization can prove to be a cost effective method of roadway maintenance.
Excavation within granular materials generally requires cutbacks of the excavation walls at a 1 to 1 slope. In confined areas, this can lead to undermining of concrete sidewalks, asphalt pavements and adjacent structures. This will result in unsafe conditions and/or extensive rehab costs. Consolidation grouting, prior to excavation, can substantially reduce excavation cutbacks by stabilizing these insitu granular materials, resulting in a safer excavation and reduced overall rehab costs.