Cohesive soils generally have low permeability characteristics. Consolidation of this soil type relies on the ability to evacuate water out of the soil matrix. This process can take a considerable time without intervention. Installing a network of Vertical Drains creates clear drainage pathways, which combined with post installation pre-loading or surcharging, greatly accelerates the duration of the consolidation.
Depending upon the requirements for the project and its ground conditions, there are various types of vertical drains (round and flat) which come in a variety of sizes to suit the required consolidation period.
Menard VacuumTM is an atmospheric consolidation technique, which is used to accelerate the consolidation of cohesive, very compressible soils. Negative pressure is created when an airtight membrane is laid over the soil, and this generates an atmospheric pressure on the soil. With early pre-loading this can significantly reduce the duration of consolidation.