Abstract: A stop-end pipe is used for formation of joining surfaces between adjacent wall elements made from a concrete casting, of the type consisting of a substantially trapezium-shaped profiled section divided up into at least two wings these wings are resiliently approachable to one another and also have a double internal reinforcing partition able to prevent collapsing as a result of compression. Preferably, the double partition is partially widened out so as to form a guide channel in which a guiding pawl for a working tool is able to slide.

Abstract: A cavity is excavated in the earth with preferably sloping sidewalls and a first impervious barrier or layer is placed on the surface of the excavation, such as a layer of plastic film or sheet. One or more self-starting pumps are placed at intervals along the slope and embedded in a pervious layer, such as sand, of from one to three feet in thickness. An inner impervious layer which, in a preferred embodiment, is substantially thicker than the outer or first impervious layer is layed over the sand and then a final layer or cap of clay is applied over the inner impervious plastic layer. Any seepage or leakage through the inner impervious layer caused by a tear or imperfection in the plastic, flows down to the self-starting monitoring pumps which, upon sensing the flow, turns itself on. The invention includes sensing the time of operation of the self-monitoring pump to determine the degree of seepage.

Abstract: Apparatus and method for constructing an impervious underground wall in which an initial excavation, filled with an excavating slurry, is made having a length L.sub.1. A milling excavator is lowered to the bottom of the initial excavation in a collapsed condition and then expanded outwardly by a linkage mechanism in the direction of the trench portion, transmitting a reaction or bearing force to a wall of the initial excavation to excavate from the bottom upwardly. The cuttings fall to the bottom of the trench and are removed by suction or an air lift. The initial excavation is thus expanded laterally from the bottom up with the excavation forces from the excavation being transmitted to the opposing wall surface. Precast concrete panels having convave sides, one concave and one convex end, are inserted into the excavation and have formations on the end to interlock with one another and serve as an excavating guide for the excavating tool.

Abstract: According to the present invention, tunnels, particularly shallow tunnels, are constructed by excavating slurry filled cross-trenches in a direction transverse to the axis of the tunnel and at regular intervals along the line or axis of the tunnel. Prefabricated frame elements are inserted into the cross-trenches to, in essence, create the tunnel wall lateral support structure before the tunnel walls are installed. Then the tunnel sidewalls are excavated under bentonite clay or mud slurry to form cross-slots between the previously installed support frames. Precast concrete sidewalls or panels are inserted between the support frames. The frames and sidewalls have interlocking tongue and groove or keyway structures so as to interfit and lock same into position.

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.

Abstract: A leachate and pollutant drainage barrier system is formed by excavating a narrow slit or slot in the earth in the presence of a reversable slurry mud which changes from a highly viscous character after a predetermined period of time (approximately 5-7 days) needed to maintain the trench open to permit the laying of a drainage pipe at the bottom of the trench and the filling of the trench with a pervious fill, such as gravel, etc. After the fill has been installed, lateral support for the earth walls is provided by the pervious fill material and the slurry reverts to a liquid having a substantially lower viscosity which may be drained via the drain pipe in the bottom of the trench. In a preferred embodiment the slurry is a biodegradable polymer. In addition, a plastic film or layer can be installed in the trench.

Abstract: High density polyethylene sheets are sealed at their lateral edges to form a sheath or envelope for sandwiching a drain mesh. A plurality of spaced apart bore holes is formed along the line of the cut-off and drain barrier and a coupling member is positioned, one in each bore hole, respectively, each coupling member having at least one locking keyway slot formed in a side thereof. These coupling members have stainless steel keyway protectors or cement stops so that cementious material cast in the bore holes so as to stabilize the coupling members do not fill the keyways. After the cementious material has set, the space between bore holes up to the keyway slots is excavated including the cementious material between the facing edges of the keyway material. Then the drain barrier with rigidifying perforated pipes secured in the ends thereof is inserted into the excavated slot with the perforated pipes being telescopically received in and retained by the keyway slots.

Abstract: Improvement on the method and apparatus for forming reinforced concrete walls with continuous steel reinforcements is disclosed in Veder U.S. Pat. No. 3,310,952. The process includes the forming of a plurality of concrete panels, each panel having a reinforcing cage extending to proximate the joint between the concrete panels and one or more expansible joint reinforcing cages bridging the gap between the reinforcing cages in the adjoining panels. The expansible joint reinforcing cages are carried in carriers in an end stop pipe. Each expansible joint reinforcing cage is comprised of a vertical support bar having secured thereto a plurality of horizontally extending concrete anchor members rigidly secured to one surface of the vertical support bar.

Abstract: A system for constructing narrow underground walls utilizing the slurry trench method is disclosed wherein a first apparatus excavates from one end of a slurry filled trench and a second apparatus is utilized for filling the trench with a wall forming material and at least a part of the excavating and/or filling apparatus is floated on the slurry in the trench. In one disclosed embodiment, narrow cut-off walls are formed by excavating from one end of a slurry filled trench and backfilling the trench at the opposite end by depositing therein a mixture of excavated soil and bentonite slurry from the trench, and includes a relatively large float adapted to be immersed in the slurry to prevent loading on the trench walls and stabilizing the apparatus for excavating purposes.

Abstract: High density polyethylene sheets are installed in panel forms to form an impervious barrier to fluid flow particularly corrosive contaminates and pollutants. A slit is excavated in the earth under a bentonite slurry to the required depth. A relatively thick, high density polyethylene sheet is placed in the trench and connected to two high density polyethylene pipes or channel members, the width of which, in the direction transverse to the direction of the wall, is the width of the trench. The panel length typically will be 15 to 30 feet. Once the high density polyethylene panel is installed, the slurry is displaced on both sides by a backfill material that can be a soil-bentonite, cement-bentonite or concrete. A secondary panel section intermediate two previously formed primary panels is made using a secondary panel of high density polyethylene similarly constructed but using smaller diameter pipe or channel members than the primary panel pipes.

Abstract: This invention relates to slurry method and apparatus for forming panelized concrete walls with a positive seal between joints. The invention is basically an improvement on the process disclosed in Veder U.S. Pat. No. 3,310,952. The slurry method or process includes the formation of a plurality of overlapping trench sections in the presence of a slurry, typically a thixotropic bentonite, with the overlapping ends between trench sections being maintained open by a hollow tubular pipe member. The joint between the concrete panels include a positive seal member bridging the gap between the adjoining panels. Portions of the positive seal members according to this invention are carried furled or folded in slots in the end stop pipe. Each furled seal portion is comprised of a vertical support bar having sealingly secured thereto a plurality of horizontally extending anchor and seal portions rigidly secured to one surface of the vertical support bar where the concrete is to be poured in a panel section.

Abstract: Reinforced concrete walls, particularly circular shafts are constructed in difficult and rocky ground by casting a pair of guide walls spaced apart a distance larger than the nominal thickness of the final wall structure and the trench excavation for the wall is carried out between the two guide walls. Initially, backfilling is of a plastic erodable mixture such as cement-bentonite, sand-cement-bentonite, which have no large aggregates. At the surface above the guide walls, forms are set for casting the reinforced structures which are to form the concrete wall per se and hollow pipes are embedded in the structure at spaced intervals, each with pipe couplings extending out of the concrete, along with the vertical runs of the steel reinforcing bars, for the next succeeding section. Water is then injected into the pipes gradually washing the erodable backfill material and facilitating the descent of the cast concrete section, which is lowered by jacks anchored to the guide walls.

Abstract: There is disclosed a method, apparatus and system for in situ relining underground pipes, lines and passageways particularly sewer lines. A sewer line which has deteriorated and/or otherwise requires repair is cleaned in a conventional manner by use of high pressure water jets to dislodge debris and clean the line, a T.V. inspection of the line is made to determine where the defects are located and to make a log of all ties and intersects. A moisture barrier, such as a thin polyethylene film, is installed along with a resin impregnable felt liner, the polyethylene film serving to prevent absorption of water or other moisture or contaminant by the felt liner and permitting thereby full absorption of resin by the liner. With the upstream end of the felt tube molded or otherwise sealed to the existing end of the sewer line a steel rod is then passed through the inside of the felt liner between the two points between which the repair is being made.