Method and apparatus of constructing a novel underground impervious barrier

Abstract

A novel underground impervious barrier is constructed by excavating a trench or slot along the desired line of the impervious barrier in the presence of a bentonite slurry. A double layered plastic film or sheet joined or folded at the bottom of the trench to form a sheath or envelope and open at the top and of sufficient vertical extent to extend above the ground and drape on both sides of the trench is installed in the trench and as the plastic sheath or envelope is installed in the trench it is hydraulically backfilled between the two facing surfaces thereof with a backfilling material having a greater density than the density of the bentonite slurry to sink the double layer plastic film or sheet to the bottom of the trench and displace the bentonite slurry forward in the trench toward the end being excavated. The impervious barrier constructed is constituted by the areas of the earth on the two facing side walls of the trench which are permeated by bentonite, each side wall having a bentonite cake contiguous thereto, a plastic membrane contiguous to the outer surface of the bentonite cake and the backfill material between the facing surfaces of the plastic membrane. Such a barrier is very useful for pollution control, for imponding water and/or otherwise effectively impeding horizontal flow of pollutants, water, oil and other flowable and/or substances leachable through the earth materials.

Dependencies are inferred from the claim text.