Method for the construction of impermeable walls

Claim 1

A method for the construction of an impermeable concrete wall in the ground, comprising the steps of excavating a first series of slots of predetermined length, width and depth along a predetermined line and of any desired shape, the first series having spaces of predetermined length between each slot, at the same time removing soil from the slots and replacing the soil with a thixotropic fluid, inserting vertical membranes in at least one end of the first series of slots with concrete to form first concrete panels such that approximately half the crosssections of each of the vertical membranes are within the first concrete panels, excavating the soil from the spaces to form a second series of slots, and at the same time replacing the soil with thixotropic fluid, filling the second series of slots with concrete to form second concrete panels such that at least one end of the second concrete panels abuts at least one end of the first concrete panels and the remaining half of the crosssections of each of the flexible membranes are within the second concrete panels, the method being further characterized in that during the pouring of the trixothropic fluid and subsequently the concrete, the membrane is supported by a steel frame bordering the end of the slot, the steel frame engaging the membrane with at least one rigid vertical edge which supports the membrane in a vertical position and slides freely vertically relative thereto so that it supports the membrane where it engages it regardless of its vertical position relative to the membrane, and including the step of removing the steel frame gradually as the concrete starts to harden at its lower end, and at essentially the same vertical rate as the concrete hardens from the bottom upwardly so that the bottom of the steel frame gradually moves above concrete hard enough to be self-supporting but not sufficiently hard to bond to the steel frame, the steel frame moving slidably along and still supporting the vertical membrane as it moves upwardly therealong.

Claim 2

A method for the construction of an impermeable concrete wall in the ground, comprising the steps of excavating a first series of slots of predetermined length, width and depth along a predetermined line and of any desired shape, the first series having spaces of predetermined length between each slot, at the same time removing soil from the slots and replacing the soil with a thixotropic fluid, inserting vertical membranes in at least one end of the first series of slots with concrete to form first concrete panels such that approximately half the crosssections of each of the vertical membranes are within the first concrete panels, excavating the soil from the spaces to form a second series of slots, and at the same time replacing the soil with thixotropic fluid, filling the second series of slots with concrete to form second concrete panels such that at least one end of the second concrete panels abuts at least one end of the first concrete panels and the remaining half of the crosssections of each of the flexible membranes are within the second concrete panels, the method being further characterized in that during the pouring of the trixothropic fluid and subsequently the concrete, the membrane is supported by a steel frame bordering the end of the slot, the steel frame engaging the membrane with at least one rigid vertical edge which supports the membrane in a vertical position and slides freely vertically relative thereto so that it supports the membrane where it engages it regardless of its vertical position relative to the membrane, and including the step of removing the steel frame gradually as the concrete starts to harden at its lower end, and at essentially the same vertical rate as the concrete hardens from the bottom upwardly so that the bottom of the steel frame gradually moves above concrete hard enough to be self-supporting but not sufficiently hard to bond to the steel frame, the steel frame moving slidably along and still supporting the vertical membrane as it moves upwardly therealong.