Abstract: A method of forming an in-situ void system including the steps of determining an expansion potential of soil adjacent to a structure and forming an array of voids in an area adjacent to the structure so as to accommodate the expansion potential of the soil. The array of voids is formed by drilling an array of holes beneath the structure or around a perimeter of the structure. The holes are drilled to a depth of the expansion potential. A liquid can be introduced into the voids so as to swell the soil. The top of the array of voids is covered prior to laying the foundation over the array of voids.

Abstract: A method and apparatus for installation of a support pier for a structure comprises positioning a hollow tube apparatus in a soil matrix wherein the hollow tube apparatus has a hollow core and is susceptible to lateral and longitudinal movement, removing soil from the hollow core and then filling that core with an aggregate followed by raising and lowering of the hollow tube apparatus by a bottom mechanical device in a manner which compacts the aggregate and also applies lateral forces to the aggregate against the walls of the cavity in the soil matrix, pushing a portion of the aggregate into the soil matrix.

Abstract: The present invention discloses a system and method for the use of structural support members, usually soldier beams, that are placed into the ground for the temporary earth support system as part of the permanent foundation wall of a supported structure. The beams are accurately placed using known SMW technology into a series or plurality of adjacent soilcrete columns also constructed with known technology. The beams are placed in the soilcrete columns as they are being constructed and prior to excavation. As excavation proceeds and the columns have set up, a portion of the interior side of the soil-cement is trimmed to the front of and exposing the front flange of the soldier beam. At this time, connectors, typically shear studs, are welded to the front of the beams.

Abstract: A method and apparatus for installing a pile or load-bearing element into soft ground, wherein a non-percussive force, rather than a percussive force such as that applied by a hammer or a jack, is applied to the top of a hole-forming tool or pile (1) so as to push the hole-forming tool or pile (1) in a substantially continuous motion to a first depth into the ground, and wherein the hole-forming tool or pile (1) is then pushed in a non-percussive manner to a second depth while being simultaneously rotated. A cast-in-situ pile is formed in soft ground by pushing a hole-forming tool (1) provided with fins (3) at its base into the ground. Once the required level has been reached, the hole-forming tool (1) is rotated and concrete or grout is pumped through the body of the hole-forming tool so as concomitantly to help displace and replace the soil swept away by the fins (3).

Abstract: An economical, high strength, highly corrosion-resistant, multi-section concrete support structure includes a first concrete section attached to a second concrete section. The first concrete section consists of a first concrete type and the second concrete section consists of a diverse, second concrete type.

Abstract: A building foundation form apparatus and method uses transverse form supports (15) supported directly on the ground and carrying longitudinal form supports (21, 22) adjustably located on opposite sides of, and substantially parallel to, a foundation axis (17). A flexible sheet form element (25) has edge portions (57, 58) connected to the longitudinal form supports (21, 22) and a contact portion (60) located between the edge portions and supported on the ground and deformed into a general U-shape with overhanging bulges (39) to receive the flowable and settable foundation mixture. The longitudinal form supports (21, 22) are adjustable vertically to accommodate ground undulations to ensure correct footing width. The contact portion (60) has mesh opening to pass the foundation mixture therethrough to enhance adhesion to the ground.

Abstract: A method for making piles apparatus for practicing the method of the invention are disclosed. The invention may be used to support the foundation of a structure, such as a building. The method draws one or more soil displacing members on a shaft down through a body of soil by turning a screw at the lower end of the shaft. The soil displacing members force soil out of a cylindrical region around the shaft. The cylindrical region is filled with grout to encapsulate and strengthen the shaft. The grout may be fed by gravity from a bath of grout around the shaft. The methods of the invention may be used to make stepped piers at much lower cost than existing methods. The invention provides methods for coating the screw portion of a screw pier with grout to protect the screw from the action of corrosive soils and to reinforce helical screws.

Abstract: Soil-displacing screw auger which contains an auger tube (1); a double displacement body (2) equipped with a hollow shaft (8) fixed to the auger tube (1) and containing an upper part (6) which constitutes a closed screw the radius of which increases towards its lower extremity and a lower part (7) which constitutes a closed screw the radius of which decreases towards its lower extremity, preferably with the same pitch as the upper part (6); a lower tube the diameter of which is smaller than twice the largest radius (R2) of the displacement body and which is situated between the lower part (7) of the displacement body (2) and the lower extremity of the auger; a screw blade (4) welded onto the outer casing of the lower tube, which rotates in the same sense as the lower part (7) of the displacement body (2) and an auger tip (5) connected to the lower extremity of the lower tube, with the special characteristic that the lower tube of the auger is an intermediate tube (3) with an outer diameter (D3) which is small

Abstract: A rotary displacement piling equipment for boring a hole within the soil comprising:

Abstract: A method is provided for forming an interconnected underground structure which avoids settling of adjacent soil structure. A plurality of underground support columns is initially formed, with the support columns being spaced apart in a predetermined pattern. Interconnecting holes are thereafter formed between the underground support columns, wherein the interconnecting holes are formed by mechanically cutting the soil and simultaneously hydraulically mixing the mechanically cut soil with slurry injected at velocities of 200 feet per second or higher while maintaining a positive hydrostatic head in the hole relative to adjacent soil. As the interconnecting holes are being formed, the diameter of each interconnecting hole is extended by positioning a second high velocity slurry nozzle near the outer diameter of the interconnecting hole which injects high velocity into the adjacent soil to hydraulically cut the adjacent soil and mix it with the slurry.

Abstract: A method is provided for centrifugally forming a subterranean, cylindrically shaped soil-cement casing in material located in a subterranean earth situs. A soil processing tool is advanced and rotated into the subterranean situs and as the tool advances a high velocity cement slurry is introduced through said tool to hydraulically divide the pieces of soil into particles and to mix the cement slurry with the particles to form a soil-cement slurry. As the soil processing tool is then withdrawn from the situs, the tool is rotated at a speed to exert a centrifugal force by the tool on the soil-cement slurry in excess of two G's, causing the solids of the soil-cement slurry to migrate away from the center of the hole to form a first cylindrical region at the edge of the hole and a second cylindrical region at the center of the hole. The first region has more of the dense solids and the second internal region has a greater proportion of free water and less of the dense solids.

Abstract: 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: The present invention provides a soil pile and method for constructing same that uses a stirred mixture that includes excess stirred mixture resulting from a prior construction, e.g., a prior soil pile construction. The stirred mixture is composed of consolidation agents and earth/sand. Water can be added to the stirred mixture so that it is easier to pump. Additional amounts of consolidation agents can be added to the stirred mixture to increase the strength of the soil pile. The stirred mixture is pumped into a borehole either as the hole is bored or after the hole is bored and earth/sand is removed. The stirred mixture can also be dried and pulverized before being used for the soil pile of the present invention.

Abstract: There is disclosed a method of continuous flight auger piling and a continuous flight auger rig (1), wherein an auger (2) is applied to the ground so as to undergo a first, penetration phase and a second, withdrawal phase, and wherein the rotational speed of and/or the rate of penetration of and/or the torque applied to the auger (2) during the first, penetration phase are determined and controlled as a function of the ground conditions and the auger geometry by means of an electronic computer (8) so as to tend to keep the auger flights loaded (11) with soil originating from the region of the tip of the auger (2).

Abstract: A drilled, cast-in-place shell pile in the form of a cementacious pipe surrounding an earthen core. The pile is cast in an annular kerf drilled in the soil with a rotating hollow cylindrical core barrel. The earthen core within the annular kerf remains in place to form the core of the shell pile and act as a form. The cylindrical shell of the pile transfers load from above to the soil mass below through skin friction, and may be reinforced against tension loads by a plurality of reinforcing bars. The earthen core has end bearing capabilities to assist in transferring loads from above. Soil excavated from the annular kerf may be mixed with cement to form a cementitious soil/cement mixture to be pumped into the annular kerf to form the cylindrical shell. This cementitious mixture, while in a fluid state, is pumped into the excavation as the core barrel is removed. A mixing/circulating unit is provided for on-site mixing of dry cement with the cuttings and other materials to form the cylindrical shell.

Abstract: A pile driving system and method of operation for driving pile casings formed of a material which is a composite of fiberglass and a resin matrix. The pile casing is sleeved on a mandrel which receives driving forces from a hammer. The driving forces are directed from the mandrel into a boot plate which penetrates down as it makes a hole in the soil. The pile casing rides down with the mandrel, and as the depth increases additional sections of pile casings and mandrel segments can be added. Trapping devices are provided for trapping the pile casing relative to the mandrel so that a portion of the driving forces are directed into the pile casing.

Abstract: This invention concerns a coupling for connecting two rods, said coupling being characterised by a cylindrical hollow body closed at one end with a jaw-shaped bottom wall and a clamp consisting of two jaws housed and sliding in a sleeve placed in a off-centre and slanted position with respect to said body.

Abstract: Device for production of material columns in the ground, in particular of compact columns or drains, with a apparatus carrier (10), a sled (14) movably guided upon a Makler (12) for manipulation of a conveyor system, comprising at least of a deep jolt ramming machine (16) with forward thrust head and material conveyance conduit, and a cantilever beam (20) held by the Makler (12) with a rope winch (22) for manipulating a container (26), with which material can be charge wise supplied to a charge lock (18), wherein the container (26) is synchronized with and is moveable relative to the sled (14). The material flows from the charge lock (18) through a lock door (21) into the material conveyance conduit (17) and from there finally into the ground (100).

Abstract: A method to provide a stoichiometric mixture of water, lime and cement for making an in-site piling. Water to supplement existing ground water is supplied by an augur as it drills into the ground so that a substantially uniform concentration of water exists for the full depth. Then the augur, while turning, returns to the surface while it injects and stirs into the wet soil the stoichiometric amounts of lime and cement.

Abstract: An undercut excavation method is provided, which is particularly suitable as an undercut-and-fill mining method, wherein concrete posts are inserted into holes drilled in the ground and are used to support a concrete floor poured on their top ends, which serves as a roof for the lower excavation level. The bottom ends of these posts rest on resilient elements to provide protection against seismic events or excessive ground movements. Excavation beneath such roof is thereby safely carried out in areas prone to seismic events such as rock bursts or earth quakes or to excessive ground movements. The concrete posts may be attached to the resilient elements at their bottom ends, thereby producing yielding posts suitable for such excavation. For still greater safety, a double post system may be used, which involves placing a second post beside the first after excavation on a given level and tying them all together with the concrete used to make the floor/roof for the next lower level of excavation.

Abstract: A method of constructing foundation piles provides improved hole stability and bearing characteristics. A boring a hole is initially formed by drilling. A horizontal pressure is then applied to the inner walls of the hole over a vertical portion of predetermined height until a desired degree of compression is attained. Horizontal pressure is then applied over a subsequent vertical portion of an inner circumferential surface of the hole vertically adjacent to a vertical portion pressed in a preceding step of applying horizontal pressure. The steps of compression are continued until a contiguous vertical expanse of the hole is compressed to a desired degree. Alternatively, the depth of the hole may be increased sequentially following a compression operation, and the subsequently formed hole depth then horizontally compressed.

Abstract: An apparatus for forming a pile in the ground has an elongate member (12, 112), at least one helical thread flight (16, 116) on the elongate member (12, 112), and a torque transmission device (24, 124) to transmit torque from a drive structure to the elongate member (12, 112) and the at least one helical thread flight (16, 116) thereon. The outer diameter of the transmission device is greater than the outer diameter of the elongate member so that the apparatus can be inserted into the ground through a frustoconical depression (50) in the ground by rotating the torque transmission device (24, 124) in a first direction, and upon the reversal of the direction of rotation, a hole is left in the ground with a diameter which is the same as that of the transmission device, and with helical grooves of substantially the same shape as the at least one helical thread flight (16, 116).

Abstract: A pillar bag which is made from a synthetic fabric which is folded, at vertically spaced intervals, to form a number of sheaths, with each sheath housing a reinforcing ring.

Abstract: A device for drilling into the ground for the in-situ production of columns of stabilized and compacted soil, which comprises at least two parallel shafts, each shaft driving in rotation one auger, each auger being fitted with a loosening drill head. The shafts and the shanks of the augers include a bore and at least one orifice for discharging a filler material, the augers having opposite hands and being driven in counterrotation, and which furthermore have a drive for reversing the direction of rotation of the augers, said device including an even number n, at least equal to 4, of augers and in that, as seen in cross-section, the axes of the augers are centered at the vertices of a regular n-sided polygon.

Abstract: The invention provides a method for making piles and apparatus for practising the method. The piles may be used to support the foundation of a structure, such as a building. The method draws a soil displacer on a shaft down through a body of soil by turning a screw at the lower end of the shaft. The soil displacer forces soil out of a cylindrical region around the shaft. The cylindrical region is filled with grout to encapsulate and strengthen the shaft. The grout may be fed by gravity from a bath of grout around the shaft. The soil displacer has a diameter smaller than a diameter of the screw and may be a disk extending in a plane generally perpendicular to the shaft.

Abstract: An apparatus for use in compacting or densifying soils includes a tubular casing having a vertical longitudinal axis and an inside surface; a hollow tubular drive shaft aligned with the vertical longitudinal axis of the tubular casing and mounted for rotation therein; a drive motor for rotating the drive shaft; a carrier attached to the drive shaft for rotation therewith; and a cylindrical roller weight in rolling contact with the inside surface of the tubular casing. The carrier engages the roller weight for rotation about the vertical longitudinal axis of the tubular casing. The centrifugal force resulting from rotation of the roller weight is resisted by the tubular casing thereby causing vibration thereof.

Abstract: A method and apparatus for supporting various structures, and especially freestanding structures such as walkways, boardwalks, prefabricated buildings, electrical towers, and decks. The apparatus includes a pier assembly comprising a pier member connected to a helix, the pier member also having a compression member fixed to an intermediate portion thereof. The compression member having an upper end, a lower end, and an outer surface of a generally frusto-conical configuration. Upon rotation of the pier assembly, the compression member is forced downwardly into the earth thereby compressing and compacting the earth there beneath to provide a stable support structure. Furthermore, a tubular member may be inserted at the upper end of the compression member and a body of rigid material may be provided within both the compression member and the tubular member.

Abstract: The present invention is a cast-in-place foundation resist pile with substantially lateral extensions inexpensively formed before or after the cement has been poured into the pile hole excavation. In addition, the present invention preferably makes those lateral extensions of the foundation pile into at least one of the levels of soft soil where the pile hole excavation has been made in alternating levels or zones of relatively soft and hard soils.

Abstract: This apparatus includes a hopper large enough to hold material to fill a number of cavities which are backfilled to produce columns in soil by first advancing a hollow shaft attached to the hopper into the soil and flowing sand from the hopper through the shaft and into the cavity formed as the shaft is withdrawn. The material flowing from the hopper through the shaft is stopped after each column is filled by closing a valve in its flow path. The equipment is moved to the next location in the area point without having to fill the hopper, which saves time and avoids waste of material. When sand is the material, the hopper is pressurized to cause the sand to flow, as in the installation of sand drains used in making wet soils safe for the support of construction.

Abstract: A soil mixing apparatus that requires less drilling force comprises a shaft, a plurality of cutting blades, an excavation blade, an auger bit, a shear blade having an extendible finger. The cutting blades, excavation blade and auger bit are attached to rotate with the shaft. The shear blade is attached at a fixed longitudinal position along the shaft. The shear blade provides a variable length by attaching different length fingers that are adjustable to the soil conditions in which the mixing apparatus is used. The shear blade is also mounted to the shaft at an angle such that the shear blade rotates in the same direction as the excavation blade and the cutting blades, but at a much slower rotation rate.

Abstract: A casting mould for keeping the cast compound together and supporting it on casting elongated objects, standing on an underlayer and extending vertically comprises a flexible elongated envelope (3) being substantially inelastic and having an opening (7) at one end thereof for supplying cast compound (6). The envelope is arranged to be held substantially vertically while being stretched by cast compound introduced through said opening (7) so as to form a casting mould having a circular cross-section, extending vertically and supporting and keeping the cast compound together.

Abstract: A hollow, cylindrical pier foundation is constructed of cementitious material poured in situ between inner and outer cylindrical corrugated metal pipe shells. The foundation is formed within a ground pit and externally and internally back filled. The lower end of the foundation has a circumferential ring fully embedded therein and sets of inner and outer circumferentially spaced bolts have their lower ends anchored to the anchor ring, their upper ends projecting up outwardly of the top of the foundation and a majority of the midportions thereof free of connection with the cementitious material of which the foundation is constructed. The base flange of a tubular tower is positioned downwardly upon the upper end of the foundation with the upper ends of the inner and outer sets of bolts projecting upwardly through holes provided therefor in the base flange and nuts are threaded downwardly upon the upper ends of the bolts and against the base flange.

Abstract: A method and apparatus used to increase the stiffness characteristic of soil to improve its ability to support a structures and to provide a tie-back anchoring force. The apparatus includes an anchor having helixes thereon is rotated into the ground. The helical anchor is hollow and includes multiple perforated holes along its length and about its perimeter. Once, the anchor is drilled into the ground, pressurized grout is injected therein. The grout is forced through the helical anchor and out through the perforated holes. The grout fills any voids along the sides of the anchor and stiffens the surrounding soil. Once the grout hardens, it may be used in a tie-back application or to support new and old construction or the like. The grout surrounding the anchor increases its lateral support and prevents deflection thereof.

Abstract: A pre-cast reinforced concrete structural beam comprises an upstanding web (136) and at least an inwardly directed flange (138) at the base of the web, the face of the web which is innermost in use and/or the upper face of the flange having surface irregularities (236,140) formed therein into which a cast in situ floor slab can penetrate to form a mechanical lock with the beam.

Abstract: There is dug in the ground (2) by means of a digging tool, a hole in which is sunk at the same time and progressively a hollow prefabricated casing element (5) of corresponding shape. When the hole has the depth necessary to receive completely the hollow casing element (5), the digging tool is retreated, leaving in place the hollow casing element (5). Anchoring elements for the post (11) are introduced within the hollow casing element (5), as well as prefabricated leveling elements (14); and there is injected into the bottom of the hole a fluent material (18) capable of hardening to anchor within the ground (2) the prefabricated leveling elements (14) and the anchoring elements for the post (11). The post can thereafter be inserted, or the post can be inserted before the leveling elements and hardenable material are emplaced.

Abstract: A pile (18) has a preformed disc-like load spreading member (34) fixed to its upper end after the pile (18) has been driven into the ground. A recess (16) is formed around the top of the pile and can be filled with particulate material (22) to position the load spreading member (34) while a bonding agent (23) fixing the load spreading member (34) to the pile (18) sets. A downwardly converging hollow concrete conical member (40), driven into the ground, has a cover (46) placed thereon to distribute the load to the conical member (40). A pile (56) can be driven through the hollow chamber of the conical member (40) and fixed to the conical member (40) by pouring concrete into the chamber after the pile (56) has been driven.

Abstract: A corrosion-protected support element for a soil anchor or a rock anchor or a pressure pile includes a support member which is provided with a tubular casing. The hollow space between the support member and the casing is filled out by a hardening material, for example, cement mortar. The tubular casing is a plastics material tube, for example, of PE, which extends over the entire length of the support member. The plastics material tube has the same cross-section over its entire length. In the region of force-transmission between the support member and the bore hole in which the support element is placed, the plastics material tube is deformed at spaced-apart locations to deviating cross-sections having different transverse extensions.

Abstract: An apparatus for forming a pile having a predetermined pile diameter in a cast-in-place pile includes an agitating apparatus. The agitating apparatus includes a pipe having a longitudinal axis which extends into the ground, and two nozzles are respectively disposed on and supported on the pipe. Each of the plurality of nozzles produces a directional jet flow of liquid. Additionally, an arrangement is provided for supplying liquid under pressure to the two nozzles. The two nozzles are spaced apart a predetermined distance along the longitudinal axis of the pipe, and are oriented such that fluid flow from the two nozzles intersects at a predetermined radial distance from the pipe, so that a cross jet flow is established at the predetermined radial distance to establish an outermost mixing of hardener and settable mixture. A final hardened pile diameter forms at the predetermined radial distance.

Abstract: An integral combination of column and pile for use in building structures in a sandy soil. The method of formation is to provide a ground situs of suitable depth and width formed preferably by an hydraulic-powered auger. The situs is then filled with a cementitious slurry. A reinforced precast concrete column is provided having reinforcing bars extending a substantial length out of its bottom. The exposed bars are inserted into the slurry until the column merges with the slurry. Upon the hardening of the slurry, the result is an integral column and pile set into the ground.

Abstract: There is provided a cement soil apparatus of underground borer capable of improving the efficiency of operation such as pile driving in civil engineering foundation work. A screw shaft 3 and a rotary machine 4 for rotating it are disposed on a guide stilt 2 of a vehicle body 1, a down hammer 6 formed with a screw blade 5 is connected to a lower end of the screw shaft, supply conduits 10, 10' and 11, 11' for cement milk or the like are formed in the screw shaft and the down hammer, respectively, such that the supply conduits in the screw shaft are in communication with those in the down hammer, and valves 12, 12' openable by pressure are disposed in lower end portions of the supply conduits, whereby cement or the like can be supplied from the outside to the inside of a bored hole. When boring operation ends and the down hammer is pulled up, cement milk is grouted.

Abstract: A method for forming a pile by driving a thin-walled pipe is disclosed. A closed-end thin-walled pipe is driven partially into the earth until firm bearing is reached. The partially driven pipe is partially filled with a concrete and the concrete is hardened. A mandrel is inserted into the partially-driven pipe to contact the hardened concrete, and the pipe is driven downwardly further by driving with the mandrel against the concrete until driving is complete. The completely-driven pipe is then cut off and further filled with concrete to the cut-off level. Excess pipe which has been cut off is used to make up further piles.

Abstract: A soil mixing apparatus that requires less drilling force comprises a shaft, a plurality of cutting blades, an excavation blade, an auger bit, a shear blade having an extendible finger. The cutting blades, excavation blade and auger bit are attached to rotate with the shaft. The shear blade is attached at a fixed longitudinal position along the shaft. The shear blade provides a variable length by attaching different length fingers that are adjustable to the soil conditions in which the mixing apparatus is used. The shear blade is also mounted to the shaft at an angle such that the shear blade rotates in the same direction as the excavation blade and the cutting blades, but at a much slower rotation rate.

Abstract: All-around type ground reinforcing and consolidating method comprises an excavating step for forming an excavated space in a predetermined area in the ground by using a dual excavating rod composed of an outer excavating member and an inner excavating member which is movably arranged in the outer excavating member; a retracting step for retracting the inner excavating member from the outer excavating member, whereby the outer excavating member is remained in the excavated space; a check step for checking the excavated space by inserting a light member containing a battery into the excavated space; an inserting-step for inserting an injection rod into the outer excavating member; a pressure adjusting step for adjusting the pressure in the excavated space; and an injecting step for injecting a hardening material into the excavated space with retracting the outer excavating member and the injection rod, whereby the predetermined area can be consolidated.

Abstract: An apparatus for forming a pile produces a predetermined pile diameter in a cast-in-place pile. The apparatus includes an agitating arrangement which includes a pipe extending longitudinally into the ground, a plurality of agitating blades supported by the pipe for agitating a settable mixture, and a plurality of nozzles respectively disposed on and supported by respective ones of the agitating blades. Each of the plurality of nozzles produces a directional jet flow of liquid. Also, an arrangement is provided for supplying liquid under pressure to each of the plurality of nozzles.

Abstract: A means of leveling and repairing an existing concrete foundation that has failed due to differential settlement, subsidence, soil shifting, surface faults or trees. A series of cylindrical pile segments are jacked into the soil while water jetting to a predetermined depth wherein sufficient skin friction is attained. Reinforcing steel is inserted into the stacked column of cylindrical pile segments and grout is further pumped into the cylindrical pile segments to suitably fix the reinforcing steel to the inside of the cylindrical pile segments, forming a single shaft pile further eliminating or reducing pile deflection and shear.

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.

Abstract: A foundation comprising (1) a cylindrical shell made of a cast-in-place concrete placed into a ring-like groove which is formed by excavation of the soil at the place of installation of the foundation, leaving a columnar soil located radially inward with respect to the ring-like groove without discharging the soil, and (2) an internal solidified soil formed by solidifying the columnar soil surrounded by the cylindrical shell with a chemical hardener, and a construction method therefor.

Abstract: A jig for constructing piles of concrete or similar hardenable grout material in the ground, with two, three or four parallel vibrated pipes, which are bound together by a common displacement casing and together therewith form a total cross section with closed geometric form. At the lower end, the displacement casing has sliding faces that converge obliquely downward.

Abstract: A cast-in-place concrete pile essentially consists of a lower concrete layer having fibers intermixed therein and an upper concrete layer having reinforcing elements. The lower portions of the reinforcing elements are embedded in the lower concrete layer to increase the bonding strength between the lower and upper concrete layers. The cast-in-place concrete pile of the present invention is constructed according to the following method. That is, an excavated hole is firstly formed in the ground. The reinforcing elements are placed at the upper side of the excavated hole, and then concrete including the fibers is cast into the excavated hole until the lower portions of the reinforcing elements are embedded in thus cast concrete, so that the lower concrete layer is formed. Continuously, concrete is cast onto the lower concrete layer in the excavated hole to form the upper concrete layer.