Abstract: The present invention provides a method of constructing underground structural concrete walls, using pre-cast, preferably pre-stressed, concrete panels, including: (a) casting in place a pair of parallel, opposing, underground guide walls spaced a predetermined distance apart; (b) excavating a trench, using the guide walls to guide the excavation tool, the trench having a predetermined width substantially equal to the space between the guide walls; (c) pouring a footing at the base of the trench; and (d) lowering a pre-cast panel into the trench in a desired orientation relative to the trench walls.

Abstract: The invention pertains to an excavation pit lining consisting of a slit wall of a hardening single-phase slit wall material with an exposed surface on the pit side, and also of vertical support elements placed at a distance in the single-phase slit wall material, whereby the slit wall forms a panel wall between the support elements and where the single-phase slit wall material has at least one water-retentive, lightweight aggregate.

Abstract: A method of strengthening and improving the load-bearing capacity of soft clay-containing subterranean soil comprising advancing a soil processing tool into said subterranean soil to break said soil into discrete particles; while advancing said soil processing tool into said soil, introducing an aqueous composition consisting essentially of water and a clay dispersant in an amount sufficient to disperse said discrete particles and make water from said clay available for hydration of subsequently added cement; when the soil processing tool has reached its desired depth, withdrawing same and simultaneously adding during said withdrawal a cementitious composition comprising water and a cement in a water-to-cement weight ratio of 0.4 to 1:1 and in an amount which provides a weight ratio of the total water of said aqueous dispersant containing composition, said clay soil and said cementitious composition to said cement of about 4 to 6:1; and allowing said mixture to harden.

Abstract: The present invention relates generally to a hydraulic power unit for supplying hydraulic fluid under pressure to industrial equipment, and more particularly to an auxiliary hydraulic power unit that is adapted to mount to a vehicle and supply auxiliary hydraulic power to auxiliary equipment associated with the vehicle during operation in the field.

Abstract: A protective housing (12) is provided for a sheet pile (10) and has a length extending beyond the upper end (10A) and lower end (10B) of the sheet pile (10). A separate force transmitting member (26) is mounted on the protective housing (12) and has a horizontal plate (28) engaging the upper end (10A) of the sheet pile (10) for driving the sheet pile (10) downwardly upon exertion of a downward force from a suitable power source (44) to force the protective housing (12) downwardly. To separate protective housing (12) from sheet pile (10) upon driving of the sheet pile (10) to a desired predetermined depth so that protective housing (12) may be withdrawn, a fluid pressure device (50) is mounted between protective housing (12) and the force transmitting member (26). Upon actuation of fluid pressure device (50), protective housing (12) is moved upwardly while sheet pile (10) remains in position thereby to initially break loose the protective housing (12).

Abstract: A subsurface barrier wall having a number of interconnected columns is disclosed. The columns are driven into the subsurface, one next to the other in interlocking fashion, with a percussive drive hammer. A sonic drilling tool is driven ahead of the columns. The columns include interconnecting elements which slidably couple adjacent columns together as a column is being driven into the subsurface. The barrier wall may be used to divert, contain, or remediate the migration of subsurface contaminants.

Abstract: An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably on which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

Abstract: An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

Abstract: The present invention provides resilient cement compositions and methods which are particularly useful in the construction and repair of oil and gas wells. The compositions have improved expansion properties and are basically comprised of a hydraulic cementitious material, rubber particles derived from automobile tires, sufficient water to form a pumpable slurry, and a dispersing agent.

Abstract: A cellular drainage structure is formed of a predetermined volume of a settable, water permeable, cellular concrete product. A concrete mix is formed of a uniformly graded aggregate in the size range from 1/16 inch to two inches and in a quantity corresponding to the predetermined volume; a cementitious component in the quantity range from 141 to 658 pounds per cubic yard of product; water in quantity sufficient to create a water-to-cement ratio in the approximate range from 0.30 to 0.55 and sufficient to wet the aggregate, establishing a cementitious-component-and-water matrix of determinable volume; a pre-formed surfactant foam, generated from an aqueous surfactant mixture at a dilution of from approximately 3 to 25 grams per liter of surfactant in water, wherein the pre-formed foam is in the density range of from 2.0 to 3.0 pcf, and the foam is added in the quantity range of 5% to 30% of the volume of the cementitious-component-and-water matrix.

Abstract: An apparatus for constructing a subsurface containment barrier under a waste site disposed in soil is provided. The apparatus uses a reciprocating cutting and barrier forming device which forms a continuous elongate panel through the soil having a defined width. The reciprocating cutting and barrier forming device has multiple jets which eject a high pressure slurry mixture through an arcuate path or transversely across the panel being formed. A horizontal barrier can be formed by overlapping a plurality of such panels. The cutting device and barrier forming device is pulled through the soil by two substantially parallel pulling pipes which are directionally drilled under the waste site. A tractor or other pulling device is attached to the pulling pipes at one end and the cutting and barrier forming device is attached at the other. The tractor pulls the cutting and barrier forming device through the soil under the waste site without intersecting the waste site.

Abstract: An underground dam is formed of a water flow preventing wall for blocking a water permeable layer of soil to form a storing portion for storing underground water on an upper stream side relative to the water flow preventing wall. The water flow preventing wall has an opening, and an opening-closing device for opening and closing the opening is provided. Thus, the underground water on the upper stream side can be supplied to a down stream side through the opening.

Abstract: A method and an apparatus is provided for forming successive overlapping voids in the ground along a predetermined course of travel and for producing a subterranean wall therein. The apparatus includes a mandrel for forming voids in the ground, and a pattern guide templet having repeating contours arranged on the ground for accurately guiding the mandrel along the predetermined course of travel during successive mandrel insertions. The mandrel includes a plurality of downwardly projecting spaced-apart cutting teeth for facilitating penetration of the mandrel into the ground, and a plurality of downwardly projecting high pressure nozzles for discharging an injectable material (e.g., slurry material or water) into the ground as the mandrel is inserted therein.

Abstract: A bulkhead for manufacturing underground structures such as earth cavities in a closed construction method, formed of sealing walls arranged as an enclosure and sealing earth masses to be removed against ground water, wherein the sealing walls are formed of a hardened mixture of bentonite-cement injected under pressure into the ground, characterized in that the sealing walls inserted into fine sand or silts are arranged in the form of a roof and are formed as a substantially elastically deformable bulkhead envelope by adding filler to the mixture of bentonite-cement. Preferably, the bulkhead sealing walls of the bulkhead envelope extend from a central ridge line on the earth surface or below it downwardly in an obliquely diverging direction into water-impermeable soil. The bulkhead can be made airtight so that a vacuum can be applied to the earth mass enclosed by the bulkhead envelope.

Abstract: A process for exactly holding the vertical excavation direction of a diaphragm wall using a hydraulic diaphragm wall grab cooperating with an excavator and having an outer guide body and an inner body for receiving the grab appliance is improved and rendered considerably more efficient by the fact that the vertical position of the inner body and/or the guide body is continuously controlled by means of an inclination detector whose-signals are transferred to a controller which, in case the bodies of the grab deviate from the predetermined vertical position, compensates said deviation by swivelling the inner body relative to the guide body in opposite direction to the deviation.

Abstract: An apparatus for delivering liner material into a trench prevents sidewall collapse in a subsurface water saturated zone, provides for inspection of vertical joints, avoids the necessity for dewatering of an area to be trenched, and provides continuous rolls of liner material which are joined by vertical and horizontal seams to accommodate any length or configuration of placement. To initiate unrolling of a length of liner material, a roll of material is dropped into the installation apparatus which trenches into the subsurface. One end of the liner material is held in place by restraints and hydraulic presses. The roll is then unrolled by trenching backwards, cutting a trench and unfurling the roll in the formed trench.

Abstract: A method for underground excavation below an area, without opening the area above the excavation, the method comprising constructing at least a pair of diaphragm walls, the walls being at two opposite sides of the area and extend substantially from the surface area to beneath the lowest level of the excavation. Either prior or after constructing the walls, a plurality of tunnels are bored under the surface area, with the tunnels extending from one diaphragm wall of a pair to another and having a diameter allowing them to accommodate one or more cables. Then, the one or more cables are inserted through the tunnels, and tensioned with their ends anchored to two diaphragm walls of a pair and excavating is performed between said diaphragm walls and beneath the cables.

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions and methods of using the set retarded cement compositions for cementing subterranean zones in wells. A preferred set retarding additive comprises an alkanolamine salt produced by the reaction of a hydroxy carboxy acid, such as tartaric acid, gluconic acid or glucoheptonic acid, with an alkanolamine, such as monoethanolamine, diethanolamine or triethanolamine.

Abstract: A system for in situ decontamination of contaminated soil in a contaminated zone comprising:a. a metal section placed in the contaminated soil,b. a heating means attached to said metal section for heating said metal section,andc. an extraction system adjacent or near said metal section for withdrawing vapors and condensates generated from heating the contaminated soil.

Abstract: A device for the extrusion of two component or two-part synthetic resins, in particular in underground mining and tunnel construction, which essentially consists of an extrusion pump in the form of an axial piston pump, exhibiting or having two pump stages or steps, located in a transportable frame, whereby each pump stage or step is connectable to reservoirs containing the synthetic resin components or parts via hose lines.

Abstract: Liquid hardeners for soil grouting formulations having an acid content no more than 0.1 mg KOH per gm in the form of dimethyl ester mixtures of dimethyl succinate, dimethyl glutarate and dimethyl adipate at a concentration in the mixtures lying within a bounded area in the graph of the drawing of the specification.

Abstract: The digging bits system contains left, right and central cylindrical digging bits and left and right plate digging bits being installed between the cylindrical digging bits, respectively. To the cylindrical digging bits, percussion force and turning force are applied. Each of the cylindrical digging bit contains tip, intermediate and upper end tubular body and is provided with a pore therein, respectively. To each of the tip tubular body, a bit edge is fixed, respectively. To both of the upper and the under end sides of the middle tubular body, a cam is provided in one unit with the tubular body, respectively. Each of the plate digging bits contains a sleeve, a central sleeve and a plurality of bit pieces, respectively. The cylindrical digging bits are rotatably connected with each other via a connecting member.

Abstract: Method of admixing and placing a substantially non-flowable cementitious material into an underground space, such as a mine shaft or the like. In a preferred embodiment, a cement slurry including about 95% Class F fly ash and about 5% hydraulic cement is admixed with an activator using a high intensity mixer to form a substantially non-flowable cementitious material, wherein the substantially non-flowable material is pumped through a conduit and placed into the underground space. The cementitious material does not flow away from the area of placement.

Abstract: A multi-shaft drilling unit having three auger shafts for developing a continuous under ground wall and comprises a housing for retaining pitch between the auger shafts, the housing comprising, primary transfer gears rotating around a central auger shaft, secondary transfer gears engaging with the primary transfer gears, a tertiary transfer gear connected to the primary transfer gear, a quaternary transfer gear connected to the tertiary gear and fixed to a rotary shaft orthogonally crossing a straight line connecting auger shaft centers, and cone-shaped cutters expanding the diameter outward and fixed on both ends of the rotary shaft. The cutters cut off a triangular convex and form a continuous wall unit of which both ends form a semicircle and both sides form a straight line and can be formed in subsoil.

Abstract: The present invention provides well cementing methods and compositions for use in cold environments which are particularly suitable for cementing conductor strings in deep water offshore wells. The cement compositions are basically comprised of a relatively coarse particulate hydraulic cement mixed with an ultra fine particulate hydraulic cement, sufficient water to form a pumpable slurry and a fluid loss control additive.

Abstract: Inorganic liquid filler compositions, well suited for the sealing or consolidation of ground formations or construction/building materials by injecting such composition into the fissures, cavities or interstices thereof (void volume) and permitting the composition to harden, comprise a homogeneous solution of (i) an alkali metal silicate, (ii) an alkali metal polyphosphate and (iii) an alkali metal aluminate.

Abstract: A hazardous waste barrier system for preventing the generally lateral, subterranean migration of certain fluid substances (including both liquid and gaseous fluids) beyond an established perimeter, while providing controlled collection of same for monitoring or disposal. The present system utilizes a barrier wall, which may be formed in-ground via horizontally rolled plastic sheeting or slidingly or otherwise engaged panels. The present system may be configured to intersect the flow path of the substance to be contained, and may be configured with additional systems to enhance containment or collection of the fluid. In use, the barrier of the present invention is installed by first making an excavation to accommodate the barrier system, and the excavation and barrier wall is implemented to a depth so as to allow for the interception with the established or anticipated migration path of the substance to be contained or collected, and/or processed.

Abstract: A non-shrink grout including Portland cement, sand and an additive which is a polymer incorporating at least one of a calcium compound and aluminum metal so as to be reactive with the cement. The grout when fresh expands during curing by gas formation and by hydration and expands when hardened. The grout is useful in construction.

Abstract: A system for construction or reconstructing building foundations involving prefabricated members (1) of a sectional monolithic wall in ground comprised of a reinforcing cage and a concrete body with longitudinal curvilinear slots (2) on end faces, offset towards one of the longitudinal sides of the body and forming thicker (3) and thinner (4) projections. The reinforcing cage consists of an external sheet reinforcement (6), cross bars (7) and intersection bars 95) rigidly connected to the sheet reinforcement (6) and to cross bars (7). The cross bars (7) and sheet reinforcement (6) may have free lengths (9, 10, 11). A sectional monolithic wall in ground built up from said prefabricated members (1) is provided with continuous lateral reinforcement at the side opposite to the sheet reinforcement (6).

Abstract: An apparatus for cutting soil and constructing sub-surface containment barriers, such as for constructing subsurface containment walls or basins around and under contaminated soils, comprises an elongated beam for abutting an extended length of soil. The beam comprises a cutting assembly that creates a cutting action against the extended length of abutting soil. The cutting assembly preferably comprises a conduit containing a plurality of jet ports through which high pressure fluid is ejected to impact the soil to be cut. The cutting assembly is maintained adjacent to the face of the soil to be cut. A method of cutting soil comprises generating cutting action along an extended locus of soil, and advancing the cutting action along a descending locus of the soil in response to gravity, or along a path determined by pre-placed pulling assemblies. Subsurface containment barriers are formed by when a jetted slurry or other suitable material cuts and mixes with the soil.

Abstract: A grouting composition for sealing boreholes or other cavities comprising 90.0-99.99% water swellable clay and 0.01-10.0% gelling agent. The grouting composition is mixed with fresh water to provide an easily placed, low cost, low permeability sealing composition. A preferred grouting composition contains 98-99% sodium bentonite and 1-2% cement. In use 50 pounds of the preferred grouting composition is mixed with 27-38 gallons of fresh water to produce a grouting composition containing 13.7-18.2% solids and having a fluid density equal to or greater than 9.0 lbs/gallon with a Marsh funnel viscosity equal to or greater than 50 seconds.

Abstract: A sheet pile wall is formed in the ground by excavating a first well and then excavating a second well spaced at a distance from the first well. The ground panel between the wells is then excavated to form a trench by using an excavating apparatus which is fitted with tubular guiding elements which are guided by the walls of the first and second wells. A prefabricated wall element having an arched center part is placed in the trench. The prefabricated wall element has edges which have meandering side faces. The edges of the wall element are brought into sealing contact with the walls of the trench, after which the first well is filled with concrete with the side face of the edge of the wall element serving as a shuttering to form a supporting nose engaging the side face.

Abstract: A weather resistant soil cement with an open pore structure for resisting freeze-thaw damage is formed of cement, fly ash, Free aggregates, water, and an aqueous foamed surfactant, and other application specific additives. The material is uniquely suited for using indigenous soils, mill tailings, or granular waste products as the aggregate component of the mixture, although commercially produced aggregates may be used depending on economics and availability. Due to its low density and flowable nature, it can be pumped or placed by gravity and without compaction. The resulting product is a low density material with construction and mining applications, that is suited for use as a fill or mad base. Specific product formulations are easily designed to permit removal at local sites with conventional excavating equipment.

Abstract: An agricultural barrier providing a medium for supporting plant life in an arid or semi-arid land region having a ground surface, the barrier being disposed on native soil of the region, the barrier including: a first layer composed of pieces of basalt, the first layer being porous and being in contact with the native soil; a porous second layer of at least one material selected from at least one of sand and gravel, the second layer being less porous than, and overlying, the first layer; and a porous third layer containing soil which favors plant growth, the third layer being less porous than, and overlying, the second layer and having an exposed upper surface, wherein the porosities of the second and third layers differ from one another by an amount which impedes transport of soil from the first layer into the second layer. Soil for the third layer may be provided by washing salinated or contaminated soil with water and using the washed soil for the third layer.

Abstract: For providing an in-ground system for treating contaminated groundwater, of the funnel-and-gate type, a cylindrical caisson is driven into the ground. The native soil is augered out of the caisson, and porous treatment material substituted. The caisson is then withdrawn, leaving a prism of porous treatment material in the ground. A sheet metal barrier element is inserted into the ground, one portion of the element extending into the prism and the other portion into the surrounding soil. More prisms are provided as further treatment gates, and more barrier elements are arranged to funnel the groundwater through the gates.

Abstract: A high alumina wellbore cementing composition is provided, the composition comprising:a) high alumina cement; andb) a polyacrylic acid phosphinate having a molecular weight of about 3800 in an amount effective to prevent gelation of the cementing composition for a time period of at least three hours.This composition can remain pumpable for a time period sufficiently long to place the cement in a wellbore using conventional wellbore cementing procedures, and, after the composition is cured, is capable of withstanding elevated wellbore temperatures.

Abstract: Contaminated groundwater is treated in-situ, by funnelling the water through a gate or gates (23) in a watertight in-ground wall (18). Treatment material in the gate (23) breaks down the contaminant, or otherwise removes the contaminant from the flowing water. A removable caisson is first driven into the ground, excavated, and then a receptacle, for the treatment material, is lowered into the hollow interior.

Abstract: Set retarded cement compositions and methods of using the compositions for cementing zones in wells at temperatures in the range of from about 200.degree. F. to about 450.degree. F. are provided.

Abstract: A compound water-sealing sealant comprising a non-water-swelling thermoplastic resin (A), preferably a vinyl chloride resin, and a water-swelling resin (C) obtained by kneading together 10 to 97% by weight of the non-water-swelling thermoplastic resin (A) and 3 to 90% by weight of a water-swelling material (B). The compound water-sealing sealant is molded by the conjoint extrusion molding of the non-water-swelling thermoplastic resin (A) and the water-swelling resin (C). The water-swelling material (B) is a water-swelling urethane resin which is a prepolymer having isocyanate groups in which the content of terminal NCO groups amounts to 1 to 12%, preferably 2 to 7%, obtained by the reaction of polyisocyanate with at least one polyether polyol of the formulaR[(OR.sub.1)n OH]pwherein R is a polyhydric alcohol residue;(OR.sub.

Abstract: A flexible grout composition and method of disposing the composition in position, in contact with an earthen formation, such as a coating on a trench wall, or within a bore hole, for example to cement a conduit within the bore hole to prevent fluid loss, for sealing and grouting well casings, plugging abandoned wells, and waterproofing earthen structures, particularly in environments where the grout composition is in contact with contaminated water. The flexible grout composition includes a water-swellable clay, such as sodium bentonite; an optional solid particulate filler, such as an essentially nonswellable bentonite clay, such as calcium bentonite, herein defined as a bentonite clay having calcium as the predominant exchangeable cation; a water-soluble polymer; and an optional dispersing agent, such as sodium acid pyrophosphate (SAPP).

Abstract: The present invention relates to the cementitious encapsulation of waste materials and/or contaminated soils containing heavy metals, to render them immobile, and particularly to the immobilization of metals, in regulated amounts, in such wastes. A waste product comprising the metals is provided. A mixture is prepared comprising the wastes and/or contaminated soils containing heavy metals, water, and a cementitious composition. The cementitious composition comprises magnesium oxide and magnesium chloride in proportions effective to produce, with said water, a magnesium oxychloride cement. The cementitious composition is present in an amount which, on setting, is effective to immobilize the metals in the waste and/or contaminated soils. The present invention is useful for the remedial treatment of landfill sites. Alternatively, introduction of a retarding agent into the cementitious composition will permit the transportation of the mixture to another site for use and deposition.

Abstract: A method of handling solid particles is disclosed, comprising the steps of mixing the solid particles with a clay and water and forming a suspension wherein the solid particles remain suspended. The suspension is transported to an emplacement site.

Abstract: A cutoff wall liner joining method includes the steps of: (1) excavating a slurry trench; (2) positioning a first layer of liner material within the excavated trench; (3) positioning two pipes adjacent to the liner material in such a manner as to form a substantially S-shaped configuration of the liner material around the pipes; (4) back filling a portion of the trench adjacent a first one of the pipes; (5) removing the other, second one of the pipes; (6) excavating an additional portion of trench extending away from the back filled portion; (7) positioning a second layer of liner material within the newly excavated portion to form a overlapping portion of liner material; (8) positioning a pipe adjacent to the remaining pipe in the trench such that it overlays the overlapping portion of liner material, then positioning a third pipe in the excavated additional trench portion; (9) back filling a portion of the trench adjacent the third pipe; (10) removing the third pipe; (11) back filling the space left by the

Abstract: Cement set retarding additives, set retarded hydraulic cement compositions and methods of using the cement compositions for cementing zones in wells are provided. The set retarding additives are copolymers containing monomer units formed from a first monomer of acrylic acid or methacrylic acid and a second monomer of acrylamide or a derivative of acrylamide.

Abstract: An apparatus and method for the continuous generation and placement of a foamed cement grout. The assembly is mounted on a fixed or mobile frame. There is a continuous foam generator, and this supplies finished foam to an intake port of a screw-type, positive-displacement pump. Cement slurry is also supplied to the intake portion of the pump, and this is mixed with the foam in the body of the pump and discharged from this through a conduit to the injection site on a continuous basis. The ratios of foam and slurry can be adjusted on a continuous basis to compensate for variations in grout quality which are observed at the injection site. The assembly is also provided with an onboard power generator and a water pump for flushing the grout out of the injection lines.

Abstract: An apparatus, method and system for installing water impervious barrier walls underground and particularly in levees. A mobile trailer movably mounted on rails carries upstanding front and rear masts and a carrier bar therebetween that is power driven up and down the masts. Augers mounted on the carrier bar are driven into the levee surface to create overlapping holes of loosened soil. A slurry of cement based grout is pumped through the augers to be mixed with the soil by the rotating, retracting augers to produce a soil-concrete slurry. A following mobile trailer also movably mounted on the rails is moved into position over the wall segment of uncured soil-concrete slurry. The following trailer carries a supply of water impervious membrane. Mechanism on the second trailer inserts the membrane into the soil-concrete slurry to produce a water impervious barrier wall segment. The trailers are sequentially moved along the levee to install a continuous water impervious barrier wall along the levee length.

Abstract: A composition and method for forming a water-impermeable barrier in soil such as for use in closing a waste disposal cell. The composition comprises a water-impermeable sheet to each side of which has been applied an adhesive such as polybutene. The sheet is a substantially nonflammable, water-impermeable, highly stretchable film, preferably a plasticized polyvinyl chloride-based or very low density polyethylene film. The composition is applied to a first layer of soil such as a landfill site and covered with a second layer of soil. When the first layer is sloped, several rows of the composition placed in adjacent, overlapping relationship, starting at the bottom of the slope. The soil particles in the first and second soil layers adhere to the sheet and enable the slope of the first layer to approach the shear angle for that type of soil. Thus, the disposal cell can have steeper sides and hold more waste than otherwise.

Abstract: A grouting composition comprised of (a) 84-95 % by weight of granular water-swellable sodium-based bentonite, (b) 1-8 % by weight of finely divided salt-water hydratable sepiolite, and (c) 4-8% by weight of a clay stabilizer. The grout composition which contains no organic polymeric substances is mixed with fresh water to provide a pumpable, rehydratable, and easily applied grouting slurry. The slurry admixture will form a solid seal with low hydraulic conductivity and high structural stability. The grouting composition is useful for sealing the annular space around a well casing and plugging abandoned wells in practically all types of formations. A preferred grouting compostion comprises 88-90% by weight of granular sodium bentonite, 6-7% by weight of sepiolite, and 4-5% by weight of granular ammonium sulfate.

Abstract: Methods are provided for the constructing of subterranean soil-cement structures in situ. The methods utilize techniques designed to prolong the period of time in which an auger machine can operate in a bore hole without encountering difficulty due to the hardening of the soil-cement mixture. The techniques utilized include a preparatory drilling phase during which a lubricating slurry may be injected. This preparatory drilling serves to break up the soil and particularly if a lubricating slurry is used, reduce friction so that final drilling may progress more quickly. After preparatory drilling, final drilling takes place. Final drilling is divided into a downward and an upward phase. Either hardening or non-hardening slurry may be introduced and consolidated with the soil during the downward phase, but only hardening slurry is typically utilized during the upward phase of final drilling.

Abstract: An apparatus for constructing subterranean structures, soil-chemicals mixture or soil-agents mixture by using a multi-shaft auger machine to mix soil with a chemical hardener in situ. As the auger shafts of the multi-shaft auger machine penetrate the soil, spiral flights attached to the auger shaft above the initial auger blades assist soil in passing by supporting structures located between adjacent auger shafts. The spiral flights both assist in raising the soil beyond the supporting structures and also prevent reagglomeration of the soil prior to passing by the supporting structures. The spiral flights have a diameter less than that of the auger blades attached to the shaft below the spiral flights and have a connection ranging from 360 degrees to 720 degrees around the shaft.