Reduced skin friction bore casing

• US 20020031405A1
• Filed: 05/21/2001
• Published: 03/14/2002
• Est. Priority Date: 12/02/1996
• Status: Active Grant

• Current Assignee: Authoria, Inc.
• Original Assignee: Authoria, Inc.
• Inventors: Sailors, Jimmy Don, Queen, Frankie A.R.
• Granted Patent: US 6,471,446 B2
• Time in Patent Office: Days
• US Class Current: 405/249
• CPC Class Codes: E02D 23/14 Decreasing the skin friction while lowering
• CPC Class Codes: E02D 5/226 Protecting piles piles with protecting cases E02D5/60
• CPC Class Codes: E02D 5/30 made of concrete or reinforced concrete or made of steel and concrete E02D5/50 takes precedence; assembled from segments E02D5/523; prestressed concrete E02D5/58
• CPC Class Codes: E02D 7/00 Methods or apparatus for placing sheet pile bulkheads, piles, mouldpipes, or other moulds for both placing and removing E02D11/00; accessories for coupling driver to piles or the like E02D13/10; for trees or other plants A01G17/16; placing posts E04H17/26

Abstract

A preferred embodiment of the reduced skin friction bore casing is particularly suited for driving into, and removal from, soils. Preferably the bore casing is composed of a material such as steel, and includes both an exterior and interior surface that are substantially concentric about a longitudinal axis. A friction reduction coating is applied to portions of both the exterior and interior surfaces with enough strength and abrasion resistance to withstand abrasion forces applied to the bore casing during driving operations into the soils as well as extraction when required.

Claims

1. A reduced skin friction bore casing for driving into soils, said reduced skin friction bore casing comprising:

said bore casing having a longitudinal axis, a first end and a second end, an exterior surface and an interior surface, said exterior and said interior surfaces being cylindrical and defined by said first and said second ends, said exterior surface and said interior surface being concentric about said longitudinal axis; and

a friction reduction coating adhered to a first portion of said exterior surface with enough strength and abrasion resistance to withstand abrasion forces applied to said bore casing during driving operations into the soils.

2. The bore casing of claim 1, wherein said bore casing is made of steel.

3. The bore casing of claim 1, wherein said friction reduction coating is adhered to a portion of said interior surface.

4. The bore casing of claim 1, wherein the soils include a compressible soil disposed above a harder soil and said bore casing is configured to extend downwardly through the compressible soil into the harder soil, said first portion extending over the length of said bore casing such that when said bore casing is driven through the compressible soil and into the harder soil, said friction reduction coating contacts the compressible soil into which said bore casing is disposed and decreases the coefficient of friction between said exterior surface of said bore casing and the compressible soil, thereby reducing friction between said exterior surface of said bore casing and the compressible soil adjacent said bore casing when the compressible soil settles downwardly relative to said bore casing.

5. The bore casing of claim 1, wherein the soils include a compressible soil disposed above a harder soil and said bore casing is configured to extend downwardly through the compressible soil into the harder soil, said first portion extending over the length of said bore casing such that when said bore casing is driven through the compressible soil and into the harder soil, said friction reduction coating contacts the compressible soil and/or harder soil into which said bore casing is disposed and decreases the coefficient of friction between said exterior surface of said bore casing and the compressible soil and/or harder soil, thereby reducing friction between said exterior surface of said bore casing and the compressible soil and/or harder soil adjacent said bore casing when the compressible soil settles downwardly relative to said bore casing.

6. The bore casing of claim 5, wherein said friction reduction coating is further adhered to a portion of said interior surface.

7. The bore casing of claim 6, wherein said portion of said interior surface extends over entire said interior surface.

8. The bore casing of claim 6, wherein the soils have been removed from an interior volume of said bore casing such that said interior volume can receive a cementacious material, said portion of said interior surface extending over a length of said bore casing such that when said volume is filled with said cementacious material, said friction reduction coating contacts said cementacious material disposed in said volume.

9. The bore casing of claim 1, wherein said bore casing is configured to extend downward through soils, said first portion extending over a length of said bore casing such that when said bore casing is driven through the soils, said soil friction reduction coating contacts the soils into which said bore casing is disposed and decreases the coefficient of friction between said exterior surface of said bore casing and the soils.

10. The bore casing of claim 9, wherein the soils have been removed from an interior volume of said bore casing such that said interior volume can receive a cementacious material, said portion of said interior surface extending over a length of said bore casing such that when said volume is filled with said cementacious material, said friction reduction coating contacts said cementacious material disposed in said volume.

11. The bore casing of claim 1, wherein said friction reduction coating is adhered to entire said exterior surface and entire said inner surface.

12. The bore casing of claim 1, wherein said first portion extends over entire said exterior surface.

14. The method of claim 13, wherein the step of inserting further includes hammering driving, drilling and vibrational driving.

15. The method of claim 13, wherein the soils have a compressible soil layer overlying a harder soil layer, and the step of determining said portion of said exterior surface further includes:

determining the depth of the compressible soil layer;

determining a portion of said exterior surface to contact the compressible soil layer; and

wherein the friction reduction coating is adhered to said portion of said exterior surface to contact the compressible soil layer after the pile has been inserted into the soils.

16. The method of claim 13, wherein the step of adhering said friction reduction coating further includes adhering said friction reduction coating to a portion of said interior surface.

17. The method of claim 16, wherein said portion of said interior surface includes entire said interior surface.

18. The method of claim 15, wherein said portion of said interior surface coincides with said portion of said exterior surface.

19. The method of claim 18, further comprising the steps of:

excavating the soils from an inside volume of said bore casing; and

filling said inside volume with a cementacious material.

20. The method of claim 19, further including the step of extracting said bore casing from the soils prior to said cementacious material attaining solid form.

21. The method of claim 19, wherein the step of excavating the soils further includes excavating soils disposed below said bore casing.

22. The method of claim 17, wherein said portion of said exterior surface further includes the entire said exterior surface.

23. The method of claim 20, wherein said step of extracting said bore casing is performed with a vibratory driver.

25. The bore casing of claim 24, wherein said friction reduction coating is applied to entire said inner surface.

26. The bore casing of claim 24, wherein said friction reduction coating adheres to said exterior surface with enough strength and abrasion resistance to withstand abrasion forces applied to said bore casing during driving operations into the soils.

27. The bore casing of claim 25, wherein said friction reduction coating adheres to said exterior surface and said interior surface with enough strength and abrasion resistance to withstand abrasion forces applied to said bore casing during driving operations into the soils.

28. The bore casing of claim 27, wherein said bore casing is made of steel.

30. The method of claim 29, wherein said portion of said exterior surface includes entire said exterior surface.

31. The method of claim 30, wherein said portion of said interior surface includes entire said interior surface.

32. The method of claim 31, wherein said friction reduction coating adheres to said exterior surface and said interior surface with enough strength and abrasion resistance to withstand the abrasion forces applied to said bore casing during insertion operations into the soils.

33. The method of claim 29, wherein the step of applying a friction reduction coating includes either spray coating or brush coating.

34. The method of claim 30, further comprising the steps of:

inserting said bore casing into the soils;

excavating the soils from an inside volume of said bore casing; and

filling said inside volume of said bore casing with fluid concrete.

35. The method of claim 31, further comprising the steps of:

inserting said bore casing into the soils;

excavating the soils from an inside volume of said bore casing;

filling said inside volume of said bore casing with fluid concrete; and

extracting said bore casing from said soils.

37. The bore casing of claim 36, wherein said friction reduction coating is adhered to a portion of said interior surface.

38. The bore casing of claim 37, wherein said bore casing is made of steel.

39. The bore casing of claim 38, wherein said portions of said interior and said exterior surfaces includes the entire said interior and exterior surfaces.

13. A method of reducing skin friction on a bore casing configured for insertion into soils, comprising the steps of:

providing a bore casing of constant size and shape along a longitudinal axis, having an interior surface and an exterior surface;

determining a portion of said exterior surface to contact the soils;

adhering a friction reduction coating to said portion of said exterior surface with enough strength and abrasion resistance to withstand the abrasion forces applied to the pile during insertion operations into the soil; and

inserting said bore casing into the soil.

24. A reduced skin friction bore casing for driving into soils, said bore casing comprising:

said bore casing having a longitudinal axis, a first end and a second end, an exterior surface and an interior surface, said exterior surface and said interior surface being cylindrical and defined by said first end and said second end, said exterior surface and said interior surface being concentric about said longitudinal axis; and

a friction reduction coating applied to entire said exterior surface.

29. A method of reducing skin friction on a bore casing configured for insertion into soils, comprising the steps of:

providing a bore casing of constant size and shape along a longitudinal axis, having an exterior surface and an interior surface; and

applying a friction reduction coating to a portion of said exterior surface and a portion of said interior surface.

36. A reduced skin friction bore casing for driving into soils, said reduced skin friction bore casing comprising:

said bore casing having a longitudinal axis, a first end and a second end, an exterior surface and an interior surface, said exterior and said interior surfaces being cylindrical and defined by said first and said second ends, said exterior surface and said interior surface being concentric about said longitudinal axis; and

a friction reduction coating adhered to a portion of said exterior surface with enough strength and abrasion resistance to withstand abrasion forces applied to said bore casing during driving operations into the soils, said friction reduction coating being a corrosion inhibitor.

40. A method of reducing skin friction on a bore casing configured for insertion into soils, comprising the steps of:

providing a bore casing of constant size and shape along a longitudinal axis, having an exterior surface and an interior surface;

applying a friction reduction coating to a portion of said exterior surface and a portion of said interior surface, wherein said friction reduction coating adheres to said exterior surface and said interior surface with enough strength and abrasion resistance to withstand the abrasion forces applied to said bore casing during insertion operations into the soils;

inserting said bore casing into the soils;

filling said inside volume of said bore casing with fluid concrete; and

extracting said bore casing from said soils.

41. The method of claim 40, wherein said portion of said exterior surface includes entire said exterior surface.

42. The method of claim 40, wherein said portion of said interior surface includes entire said interior surface.

43. A method of installing concrete piers in the ground, comprising the steps of:

providing a bore casing of constant size and shape along a longitudinal axis, having an exterior surface and an interior surface;

adhering a friction reduction coating to at least a portion of the interior surface that is to receive liquid concrete, wherein the friction reduction coating adheres to the interior surface with enough strength and abrasion resistance to withstand the abrasion forces applied to the interior surface during withdrawal of the casing from about wet concrete;

inserting the bore casing into the ground;

filling at least a portion of the inside volume of the bore casing with concrete in liquid form;

extracting said bore casing from the ground and about the liquid concrete with the friction reduction coating providing a slip plane between the conduit and the liquid concrete.

44. The method of claim 43, and further including the step of after the bore casing has been withdrawn from about the liquid concrete and before the liquid concrete dries on the inner surface of the bore casing, washing from the inner surface of the bore casing any liquid concrete present on the inner surface of the bore casing.

45. The method of claim 43, wherein the portion of the interior surface includes the entire interior surface.