Abstract: Vertical prefabricated drains are installed into soil underlying a body of water for soil stabilization and thereafter from the surface of the water the drain member is captured within a drain cutting assembly which is lowered by an operating line that is tethered to the assembly into the water as guided by the captured drain. Then the prefabricated drain is severed below the surface of the water by actuating the cutter assembly at the water surface with the operating line.

Abstract: The effectiveness of a prefabricated earth drain installed in a generally vertical manner in soil is improved for enhancing the expelling of pore water from the soil to the surface. The soil surrounding the earth drain is hydraulically fractured either while the drain is in place or while the earth drain is being installed. Propping agents may also be supplied to the surrounding soil after hydraulic fracturing for propping fractures in the soil to maintain continuous flow to the drain. Radially extending fissures may also be formed in the surrounding soil either mechanically or through the use of hydraulic jetting and a propping agent is supplied to these fissures either in the form of particulate material or a continuous ribbon of porous filter fabric.