A sheath for constructing a reinforced concrete pile, characterized in that the sheath is formed by at least one circular knit comprising having a series of meshes helically positioned so as to form a pipe. A method for constructing a reinforced concrete pile includes excavating to form a well, inserting one end of a reinforcing rod in a sheath, positioning the sheath on an area of the rod and introducing the rod into the well, installing a tremie pipe inside the rod, and filling the well with concrete using the tremie pipe.

A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

The present invention provides a tool for forming an underground cast-in-situ pile having an enlarged base, the tool comprising: a first pile-forming member having a first base-forming member; a second pile-forming member having a second base-forming member, the pile-forming members extending collinearly and being movable in a longitudinal direction relative to one another between: a digging state wherein the base-forming members are proximate to one another so that the pile-forming members can be driven underground; and a base-forming state wherein the base-forming members are spaced from one another so as to form an underground void between the first and second base-forming members, the void being tillable with a flowable fill to form the enlarged base of the underground cast-in-situ pile; and jack screw means, rotation of which causes relative longitudinal movement between the pile-forming members.

The present invention provides a tool for forming an underground cast-in-situ pile having an enlarged base, the tool comprising: a first pile-forming member having a first base-forming member; a second pile-forming member having a second base-forming member, the pile-forming members extending collinearly and being movable in a longitudinal direction relative to one another between: a digging state wherein the base-forming members are proximate to one another so that the pile-forming members can be driven underground; and a base-forming state wherein the base-forming members are spaced from one another so as to form an underground void between the first and second base-forming members, the void being tillable with a flowable fill to form the enlarged base of the underground cast-in-situ pile; and jack screw means, rotation of which causes relative longitudinal movement between the pile-forming members.

A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

The present invention provides a tool for forming an underground cast-in-situ pile having an enlarged base, the tool comprising: a first pile-forming member having a first base-forming member; a second pile-forming member having a second base-forming member, the pile-forming members extending collinearly and being movable in a longitudinal direction relative to one another between: a digging state wherein the base-forming members are proximate to one another so that the pile-forming members can be driven underground; and a base-forming state wherein the base-forming members are spaced from one another so as to form an underground void between the first and second base-forming members, the void being tillable with a flowable fill to form the enlarged base of the underground cast-in-situ pile; and jack screw means, rotation of which causes relative longitudinal movement between the pile-forming members.

The present invention provides a tool for forming an underground cast-in-situ pile having an enlarged base, the tool comprising: a first pile-forming member having a first base-forming member; a second pile-forming member having a second base-forming member, the pile-forming members extending collinearly and being movable in a longitudinal direction relative to one another between: a digging state wherein the base-forming members are proximate to one another so that the pile-forming members can be driven underground; and a base-forming state wherein the base-forming members are spaced from one another so as to form an underground void between the first and second base-forming members, the void being tillable with a flowable fill to form the enlarged base of the underground cast-in-situ pile; and jack screw means, rotation of which causes relative longitudinal movement between the pile-forming members.

A system for forming a piling structure includes a hollow casing, a control assembly positioned proximately to the hollow casing, and a pivoting support device connected to the control assembly. A pivoting electrode is connected to the pivoting support device and configured to extend into the hollow casing. A second electrode is connected to the control assembly and extends into the hollow casing within the range of motion of the pivoting electrode. An electric power source is connected to the pivoting electrode and the second electrode, wherein charge on the electrodes produces a current arc between the pivoting electrode and the second electrode. A lift mechanism is positioned proximately to the hollow casing to control the electrodes position within the hollow casing.