Soil stabilisation - VACUUM WELL

In some cases, GART - Dewatering will use vacuum wells to dewater and stabilize the soil at a reasonable cost. Fine silty soils cannot be dewatered by classical methods due to the capillary effect that reduce the permeability of soil. Those soils can often be dewatered with a vacuum system that use vacuum wells. It is basically a deep well or a combination of wellpoint with vertical sand drain, coupled to a vacuum pump and sealed at the surface to prevent air from entering the system. The system forms a network of vacuum wells connected to high volume vacuum pumps. The vacuum produced draw the water from soil. If the depth exceed the vacuum draft height the system is combined with submersible well pumps. The water thus removed produce a consolidation of the soil and an increase in its shear strength.