Compaction Grouting

Compaction grouting is a relatively new but proven method of stabilizing fine grain soils. Its use of a very stiff, mortar-like grout differs fundamentally from conventional or penetration grouting in applicability, equipment, materials, injection procedures, and mechanism effect. The grout is injected as a homogeneous mass with a distinct interface between the grout and the soil. It will tend to move into the weakest zones and the resulting mass may be irregularly shaped. Advantages are minimum site disturbance and risk, flexibility of scope, economy, applicability where the ground-water surface is high, and ability to lift settled structures to proper grade. Its disadvantages or limitations are difficulty in analyzing results, limited application at very shallow depth or where lateral restraint is lacking and, in some cases, cost for deep work. History of the process, including a review of original research and development, is presented as well as case histories.