System and method of permafrost pile forming

• US 3,921,410 A
• Filed: 07/05/1974
• Issued: 11/25/1975
• Est. Priority Date: 07/05/1974
• Status: Expired due to Term

• Current Assignee: Kenneth W. Philo
• Original Assignee: Kenneth W. Philo
• Inventors: Philo, Kenneth W.
• Primary Examiner(s): Shapiro, Jacob
• Application Number:
  US05/486,050
• Time in Patent Office: 508 Days
• Field of Search: 61/53.5,53.52,53.64,53.66,36A,50 175/84 214/310
• US Class Current: 405/232
• CPC Class Codes: E02D 5/226 Protecting piles piles with protecting cases E02D5/60
• CPC Class Codes: E02D 5/385 with removal of the outer mould-pipes documents also covered by one or several of the groups E02D5/40 - E02D5/44 are classified in all the relevant groups

Abstract

A system and method for placing a preformed pile in permafrost or other hard ground is disclosed. The initial procedure in the system is to excavate an annulus in the ground having an outer diameter somewhat larger than the outer diameter of the pile, leaving a substantially undisturbed core. The core is then removed to provide a hole for insertion of the pile therein. The system also provides for filling the area surrounded by the inserted pile with wet sand, and allowing the sand to be frozen in place to encapsulate the pile.

Claims

1. A method for placing a pile in permafrost or other hard ground which is normally frozen, said method comprising the steps of excavating an annulus in the ground having an outer diameter slightly greater than the outer diameter of the pile and leaving a substantially undisturbed core, said excavating step including the step of placing a casing and means for dispensing sand at the lower end of the casing in said annulus;

inserting the pile into the hole inside the casing;

removing the casing from the hole and simultaneously dispensing sand with said dispensing means at the lower end of the casing to fill the space vacated around the pile as the casing is removed from the hole; and

wetting the sand so that the sand is frozen in place to encapsulate the pile.

2. A method as recited in claim 1 wherein said excavating comprises the step of percussive drilling the annulus in the ground.

3. A method as recited in claim 1 wherein said excavating includes the step of placing a core tube in the annulus, said core tube being interior of and concentric with said casing and adapted to enclose the undisturbed core, and wherein said removing step comprises removing the core tube having the core therein leaving the casing in the annulus to prevent collapse of the side walls thereof.

4. Apparatus for placing a pile in permafrost or other hard ground which is normally frozen, said apparatus comprising:

an elongate hollow casing;

means for excavating an annulus and leaving a substantially undisturbed core within said annulus, said excavating means located at the lower end of the casing;

a hollow core tube normally disposed within the casing and concentric therewith, said core tube being removable from the casing and adapted to circumscribe the core so that removal of the core tube from within the casing will lift the core from the annulus to provide a hole for placement of the pile, said hole being maintained by the casing during removal of the core tube and placement of the pile;

means for removing the casing from the hole after placement of the pile; and

means for dispensing sand as the casing is being removed from the hole into the space left by removal of the casing, said sand being wetted to freeze the sand in place to encapsulate the pile.

5. Apparatus as recited in claim 4 wherein the core tube includes means for expelling the core From the core tube after lifting the core from the annulus.

6. Apparatus as recited in claim 5 wherein the upper end of the hollow core tube is sealed, and wherein said expelling means includes means for pressurizing the upper end of the core tube to expel the core out the other end thereof.

7. Apparatus as recited in claim 4 wherein said excavating means includes a percussive drilling head.

8. A method for placing and encapsulating a pile in permafrost or other hard ground which is normally frozen, said method comprising the steps of excavating a hole in the ground having an outer diameter slightly greater than the outer diameter of the pile;

placing a hollow casing into the hole;

inserting the pile into the hole within the hollow interior of the casing;

removing the casing from the hole after insertion of the pile and simultaneously dispensing sand at the bottom of the casing into the annular void surrounding the pile left as the casing is removed from the hole; and

wetting the sand so that the sand is frozen in place to encapsulate the pile.

9. A method as recited in claim 8 wherein said wetting is performed prior to dispensing the sand into the annular void.

10. A method as recited in claim 8 wherein said wetting is performed subsequent to dispensing the sand into the annular void.

11. A method as recited in claim 8 wherein said excavating comprises the steps of excavating an annulus in the ground having an outer diameter slightly greater than the outer diameter of the pile and leaving a substantially undisturbed core, and removing the core to provide the hole.

12. A system for placing and encapsulating a pile in an excavated hole in permafrost or other hard ground which is normally frozen, said system comprising:

an elongate hollow casing adapted to occupy the excavated hole;

means for placing the pile into the hole interior of the elongate hollow casing;

means for withdrawing the casing from the hole after placement of the pile; and

means for dispensing sand at the lower end of the casing into the annular volume vacated by the casing as said casing is withdrawn from the hole, said dispensing means operating simultaneously with said withdrawing means so that the sand is dispensed as the casing is withdrawn from the hole to prevent the formation of gaps in the sand by bridging, said sand being wetted so that the sand is frozen in place to encapsulate the pile.

13. Apparatus for placing a pile in permafrost or other hard ground, said apparatus comprising:

a percussive drilling head having an annular array of downwardly directed percussive drilling teeth, said drilling head having an inwardly directed flange portion;

an elongate core tube having an open lower end adapted to rest on the flange portion of the drilling head and a closed upper end adapted to provide a striking surface for a hammer so that the drilling head is powered by the hammer to percussively drill an annulus in the ground leaving a substantially undisturbed core; and

an elongate hollow casing adapted to circumscribe the core tube, the outer diameter of the casing being substantially equal to the outer diameter of the percussive drilling head so that the casing prevents collapse of the outer walls of the annulus during the drilling thereof, the side walls of the casing having two sets of tubes extending vertically therethrough, the upper ends of the first set of tubes being connected to a source of pressurized air which passes therethrough to force soil loosened by the teeth of the drilling head upwardly through the second set of tubes and out of the annulus, the core tube being removable from the casing after drilling of the annulus to the desired depth, the undisturbed core being removed with said core tube to provide a hole for placement of the pile.

14. Apparatus as recited in claim 13 and additionally comprising a hopper located at the upper end of the casing, the upper end of the second set of tubes communicating with said hoPper to feed sand to the annular void vacated by the casing as the casing is removed from the hole after placement of the pile, said sand being wetted so that the sand freezes in place to encapsulate the pile.

15. A method for placing a pile in permafrost or other hard ground, said method comprising the steps of:

providing a percussive drilling head having an annular array of downwardly directed percussive drilling teeth;

locating the open lower end of an elongate core tube overlying at least a portion of the drilling head;

fixing the lower end of an elongate hollow casing to the percussive drilling head so that said hollow casing circumscribes the core tube;

driving the drilling head downwardly into the ground to percussively drill an annulus in said ground while leaving a substantially undisturbed core;

forcing pressurized air downwardly through a first conduit intermediate the casing and the core tube to thereby force soil loosened by the drilling teeth upwardly through a second conduit and out of the annulus;

removing the core tube from the casing after drilling of the annulus to remove the undisturbed core contained within the core tube and provide a hole for placement of the pile; and

preventing the collapse of the outer walls of the annulus with the casing during the drilling of said annulus and removal of said core tube.

16. A method as recited in claim 15 and additionally comprising the steps of removing the casing from the hole after placement of the pile and simultaneously dispensing sand at the lower end of said pile to fill the space vacated around the pile as the casing is removed from the hole, and wetting the sand so that the sand is frozen in place to encapsulate the pile.

17. A method as recited in claim 15 wherein said driving step includes the step of striking the closed upper end of the elongate core tube to drive the drilling head downwardly into the ground.

18. A method as recited in claim 1 wherein said wetting step is performed prior to said dispensing step.

19. A method as recited in claim 1 wherein said wetting step is performed subsequently to said dispensing step.