# US 11,441,285 B2 · Tool and method for forming piles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,285 B2 - Document ID: US11441285B2 - Status: Granted - Kind: B2 - Application number: 17/049,079 - Filed: 2019-04-23 - Published: 2021-08-19 - Granted: 2022-09-13 - Earliest claimed: 2018-04-25 - Assignees: Ppx Technology Pty Ltd - Applicants: Ppx Technology Pty Ltd - Inventors: Przemyslaw Adam Zakrzewski - Web page: https://patentgrep.com/patent/US11441285B2 ## CPC - E02D 7/22: Placing by screwing down {(screw piles per se E02D5/56)} - E02D 5/44: with enlarged footing or enlargements at the bottom of the pile - E02D 5/665: {for making piles} - E02D 5/66: Mould-pipes or other moulds {(for plant use B28B)} - E02D: FOUNDATIONS; EXCAVATIONS; EMBANKMENTS (specially adapted for hydraulic engineering E02B); UNDERGROUND OR UNDERWATER STRUCTURES {(tunnels, tunnelling, mining E21)} ## Abstract 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. ## Claims ### Claim 1 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 at a lower end thereof; a second pile-forming member having a second base-forming member at a lower end thereof, the first and second pile-forming members extending collinearly and being movable in a longitudinal direction relative to one another between: a digging state wherein the first and second base-forming members are proximate to one another so that together, the first and second base-forming members define a leading helix of the tool such that the first and second pile-forming members can be driven underground to form an elongate hole underground having a first diameter; and a base-forming state wherein the first and second base-forming members are spaced apart from one another in the longitudinal direction so as to form an underground void between the first and second base-forming members at a depth of the elongate hole, the void having a second diameter that is greater than the first diameter and being fillable with a flowable fill to form the enlarged base of the underground cast-in-situ pile; and a jack screw, wherein rotation of which causes relative longitudinal movement between the first and second pile-forming members. ### Claim 2 (depends on 1) The tool of claim 1, wherein the jack screw is threadingly engaged with the first pile-forming member such that rotation of the jack screw in one direction moves the first and second pile-forming members into the digging state, and rotation of the jack screw in the opposite direction moves the first and second pile-forming members into the base-forming state. ### Claim 3 (depends on 2) The tool of claim 2, wherein the jack screw and the second pile-forming member are rotatable, but not longitudinally movable, relative to one another. ### Claim 4 (depends on 3) The tool of claim 3, wherein the second pile-forming member comprises a collar via which the jack screw is secured to restrict relative longitudinal movement therebetween, and wherein a thrust bearing is disposed between the jack screw and the second pile-forming member to enable relative rotation therebetween. ### Claim 5 (depends on 1) The tool of claim 1, further comprising limiting means for limiting an extent to which the first and second base-forming members can be spaced from one another. ### Claim 6 (depends on 5) The tool of claim 5, wherein the limiting means comprises a collar extending from the jack screw, and wherein when the first and second pile-forming members are moved into the base-forming state, the first pile-forming member engages the collar, thereby limiting longitudinal movement between the first and second pile-forming members which further increases the space between the first and second base-forming members. ### Claim 7 (depends on 1) The tool of claim 1, wherein the first and second pile-forming members are telescopically arranged and configured such that one of the first and second pile-forming members cannot be rotated independently of the other of the first and second pile-forming members. ### Claim 8 (depends on 1) The tool of claim 1, wherein: the first pile-forming member is a first screw pile; the second pile-forming member is a second screw pile; the first base-forming member is a first helix; and the second base-forming member is a second helix. ### Claim 9 (depends on 8) The tool of claim 8, wherein in the digging state, the first and second helices are engaged with one another to define the leading helix of the tool. ### Claim 10 (depends on 1) The tool of claim 1, wherein: the first pile-forming member is a first blade pile; the second pile-forming member is a second blade pile; the first base-forming member is a first blade; and the second base-forming member is a second blade. ### Claim 11 (depends on 1) The tool of claim 1, wherein: the first diameter is approximately equal to a diameter of the first pile-forming member and/or a diameter of the second pile-forming member; and the second diameter is approximately equal to a diameter of the first base-forming member and/or a diameter of the second base-forming member. ### Claim 12 A method of forming an underground cast-in-situ pile having a shaft and an enlarged base, the method using a tool comprising: a first pile-forming member having a first base-forming member at a lower end thereof; a second pile-forming member having a second base-forming member at a lower end thereof, the first and second pile-forming members extending collinearly and being movable in a longitudinal direction relative to one another between: a digging state wherein the first and second base-forming members are proximate to one another so that the first and second pile-forming members can be driven underground to form an elongate hole having a first diameter; and a base-forming state wherein the first and second base-forming members are spaced apart from one another in the longitudinal direction so as to form an underground void between the first and second base-forming members at a depth of the elongate hole, the void having a second diameter that is greater than the first diameter and being fillable with a flowable fill to form the enlarged base of the underground cast-in-situ pile, the method comprising: (a) when the first and second pile-forming members are in the digging state, driving the first and second pile forming members underground to a predetermined depth to form the elongate hole; (b) moving the first and second pile-forming members towards the base-forming state to form the underground void at the depth of the elongate hole; (c) while moving the first and second pile-forming members towards the base-forming state, supplying the flowable fill to the void so as to form the enlarged base of the underground cast-in-situ pile; and (d) driving the first and second pile-forming members out of ground while supplying the flowable fill underground to form the shaft of the cast-in-situ pile. ### Claim 13 (depends on 12) The method of claim 12, wherein step (b) further comprises: (i) while moving the first and second pile-forming members towards the base-forming state, determining a magnitude of a force required to move the first and second pile-forming members towards the base-forming state; (ii) if the magnitude of the determined force is below a threshold amount, repeating steps (a) and (b) at a deeper depth underground until the magnitude of the determined force is equal to or greater than the threshold amount; and (iii) when the magnitude of the determined force is equal to or greater than the threshold amount, continuing to move the first and second pile-forming members towards the base-forming state while supplying the flowable fill to the void to form the enlarged base. ### Claim 14 (depends on 13) The method of claim 13, wherein the force relates to a torque force applied to a jack screw of the tool configured to move the first and second pile-forming members towards the base-forming state. ### Claim 15 (depends on 13) The method of claim 13, wherein the force relates to an axial force carried by one or both of the first and second pile-forming members.