Method for automatically driving gravel drain piles and execution apparatus therefor

• US 5,256,003 A
• Filed: 06/05/1992
• Issued: 10/26/1993
• Est. Priority Date: 12/26/1989
• Status: Expired due to Fees

• Current Assignee: NSK Corporation (NSK Limited), Konoike Construction Company Limited (Sekisui House Limited)
• Original Assignee: NSK Corporation (NSK Limited), Konoike Construction Company Limited (Sekisui House Limited)
• Inventors: Nakajima, Yutaka, Ito, Katsuhiko, Ichikawa, Haruo, Koike, Tadao, Okita, Yasuharu, Ikeda, Rentaro
• Primary Examiner(s): Taylor, Dennis L.
• Assistant Examiner(s): RICCI, JOHN A
• Application Number:
  US07/895,425
• Time in Patent Office: 508 Days
• Field of Search: 405/50, 405/232, 405/233, 405/240, 405/243, 405/249, 405/257, 73/84
• US Class Current: 405/232
• CPC Class Codes: E02D 3/106 by forming sand drains containing only loose aggregates sand piles E02D3/08

Abstract

A method comprising interpenetrating a hollow casing into a relatively loose sand layer saturated with ground water, thereafter raising the casing while tamping crushed stones charged into the casing by a compaction rod disposed within the casing, and driving gravel drain piles while continuously performing the raising of the casing and the tamping of the crushed stones. After the casing has reached the predetermined depth and the charging of crushed stones has been confirmed an, amplitude of reaction is detected by a reaction detection device provided on the compaction rod or a load current measuring device of the compaction rod. The reaction value is compared with a set reaction value, and one or more factors (a raising speed of the casing, a period, an amplitude and an extreme end surface-height of the compaction rod for determining a compacting degree of a peripheral ground) are controlled in response to the compared value.

Claims

1. An apparatus for driving gravel drain piles comprising:

a casing raising device for raising a hollow casing which is vertically movably guided along a leader and varying a raising speed of said casing;

a compaction rod driving device for vertically moving a compaction rod disposed within said casing;

a compaction rod reaction detection device disposed halfway of said compaction rod to detect a reaction of the compaction rod and provide a value indicative thereof;

a crushed-stone top end detection device for detecting a depth of crushed stones charged into said casing;

a casing depth detection device for detecting a depth of interpenetration of said casing; and

processing means for comparing, after said casing has reached said predetermined depth and the charging of the crushed stone has been confirmed, the detected value from said compaction rod reaction detection device with a set reaction value and controlling a raising speed of the casing through said casing raising device so as to increase, reduce or make constant the raising speed of the casing and determining a compacting degree of peripheral ground based on said compared value, said processing means being also responsive to said crushed-stone top end detection device and the casing depth detection device.

2. An apparatus for driving gravel drain piles comprising:

a casing raising device for raising a hollow casing which is vertically movably guided along a leader;

a compaction rod driving device for vertically moving a compaction rod disposed within said casing and varying a period of upward and downward movement of said compaction rod;

a compaction rod reaction detection device disposed halfway of said compaction rod to detect a reaction of the compaction rod and provide a value indicative thereof;

a crushed-stone top end detection device for detecting a depth of a top end of crushed stones charged into said casing;

a casing depth detection device for detecting an interpenetration depth of said casing; and

processing means for comparing, after said casing has reached said predetermined depth and the charging of the crushed-stones has been confirmed, the detected value from said compaction rod reaction detection device with a set reaction value and determining a compacting degree of peripheral ground based-on said compared value, wherein said processing means is responsive to said crushed-stone top end detection device and a period of the compaction rod is controlled through the compaction rod driving device.

3. An apparatus for driving gravel drain piles comprising:

a casing raising device for raising a hollow casing which is vertically movably guided along a leader;

a compaction rod drive device for vertically moving a compaction rod disposed within said casing and varying an amplitude of upward and downward movement of said compaction rod;

a compaction rod reaction detection device disposed halfway of said compaction rod to detect a reaction of the compaction rod and provide a value indicative thereof;

a crushed-stone top end detection device for detecting a depth of a top end of crushed stones charged into said casing;

a casing depth detection device for detecting an interpenetration depth of said casing; and

processing means for comparing, after said casing has reached said predetermined depth and the charging of the crushed-stones has been confirmed, the detected value from said compaction rod reaction detection device with a set reaction value and determining a compacting degree of peripheral ground based on said compared value, wherein said processing means is responsive to said crushed-stone top end detection device and an amplitude of the compaction rod is controlled through said compaction rod driving device.

4. An apparatus for driving gravel drain piles comprising:

a casing raising device for raising a hollow casing which is vertically movably guided along a leader;

a compaction rod driving device for vertically moving a compaction rod disposed within said casing;

a compaction rod height adjusting device for vertically moving said compaction rod driving device to vary a position of movement of the compaction rod into said hollow casing;

a compaction rod reaction detection device disposed halfway of said compaction rod to detect a reaction of said compaction rod and provide a value indicative thereof;

a crushed-stone top end detection device for detecting a depth of a top end of crushed stones charged into said casing;

a casing depth detection device for detecting an interpenetration depth of said casing; and

processing means for comparing, after the charging of the crushed stones has been confirmed, the detected value from said compaction rod reaction detection device with a set reaction value and determining a compacting degree of peripheral ground based on said compared value, wherein a height of an extreme end surface of the compaction rod is controlled through said compaction rod height adjusting device.

5. An apparatus for driving gravel drain piles comprising:

a casing raising device for raising a hollow casing which is vertically movably guided along a leader and varying a raising speed of said casing;

a compaction rod driving device for vertically moving a compaction rod disposed within said casing and varying a period of upward and downward movement and an amplitude of said compaction rod;

a rod height adjusting device for vertically movably supporting said compaction rod drive device to vary a position of movement of said compaction rod into said hollow casing;

a compaction rod reaction detection device disposed halfway of said compaction rod to detect a reaction of said compaction rod and provide a value indicative thereof;

a crushed-stone top end detection device for detecting a depth of a top end of crushed stones charged into said casing;

a casing depth detection device for detecting an interpenetration depth of said casing; and

processing means for comparing, after said casing has reached said predetermined depth and the charging of said crushed-stones has been confirmed, the detected value from said compaction rod reaction detection device with a set reaction value and determining a compacting degree of peripheral ground based on said compared value, wherein said processing means is responsive to said crushed-stone top end detection device and said casing depth detection device and at least one of a raising speed of the casing, a period of the compaction rod, an amplitude of the compaction rod and a height of an extreme end surface of the compaction rod are controlled through said casing raising device, said compaction rod driving device and said compaction rod height adjusting device.

6. A method for automatically driving gravel drain piles comprising the steps of:

interpenetrating a hollow casing to a predetermined depth into a relatively loose sand layer saturated with water;

raising the casing while tamping crushed-stones charged into said casing by a compaction rod disposed within said casing;

driving gravel drain piles at regular intervals within the sand layer while continuously performing the steps of raising the casing and tamping the crushed-stones by the compaction rod;

detecting a magnitude of a crushed-stone tamping reaction by a reaction detecting device provided on said compaction rod and providing a real reaction value;

comparing the real reaction value with a set reaction value which is set in correspondence to the condition of the ground;

controlling a raising speed of the casing in response to said compared value so as to increase, decrease or make constant the raising speed of the casing;

determining a compacting degree of peripheral ground based on said compared value; and

compacting the peripheral ground.

7. The method for automatically driving gravel drain piles according to claim 6, further comprising the step of controlling a period of the compaction rod.

8. The method for automatically driving gravel drain piles according to claim 6, further comprising the step of controlling an amplitude of the compaction rod.

9. The method for automatically driving gravel drain piles according to claim 6, further comprising the step of controlling a height of an extreme surface of the compaction rod.

10. A method for automatically driving gravel drain piles comprising the steps of:

interpentrating a hollow casing into a predetermined depth into a relatively loose sand layer saturated with ground water;

raising the casing while tamping crushed stones charged into said casing by a compaction rod disposed within said casing;

driving gravel drain piles at regular intervals within the sand layer while continuously performing the steps of raising the casing and tamping the crushed-stone by the compaction rod;

detecting a magnitude to a crushed-stone tamping reaction by a reaction detecting device provided on the compaction rod and providing a real reaction value;

comparing the real reaction value with a set reaction value which is set in correspondence to the condition of the ground;

controlling at least one of a raising speed of the casing, a period of the compaction rod, an amplitude of the compaction rod and a height of an extreme end surface of the compaction rod in response to said compared value;

determining a compacting degree of peripheral ground based on said compared value; and

compacting the peripheral ground.