Consolidation grouting is a general term for grouting that is carried out within a rock mass with the intent of filling rock mass discontinuities. The process involves injecting a grout material to fill the discontinuities, which are the pathways through which fluids or gases migrate in most rocks. With grout filling the rock discontinuities, the hydraulic gradient is reduced as the liquids or gases move through the grout, ultimately reducing or stopping migration. The following grouting operations often employ consolidation grouting:Pre-excavation GroutingGrout CurtainFoundation GroutingWater Cut-Off GroutingSuccessful implementation of a consolidation grouting program is contingent on development of an appropriate drilling program along with choosing a grout that is amenable to the rock mass discontinuities.We have performed consolidation grouting on numerous projects in many varying geologies. Typical projects include pre-excavation grout curtains for shafts, foundation grouting/grout curtains for dams, pre-excavation grouting for shafts, drifts, and tunnels, and water cutoff grouting for underground operations. Key in our successful completion of these projects has been our ability to configure equipment for proper drilling access and our ability to apply all types of grout.