JP5695307B2 - Small diameter steel pipe pile joint structure and small diameter steel pipe pile construction method - Google Patents

Description

  The present invention relates to a technique for joining small-diameter steel pipe piles in which a steel pipe is added and pressed to a solid ground in order to repair a building horizontally and prevent future subsidence.

Patent Documents 1 and 2 disclose techniques for correcting / reinforcing uneven settlement of buildings.
Patent Documents 3 and 4 disclose connection technology of support piles (steel pipes) that correct and reinforce uneven settlement of buildings.
Patent Document 5 discloses a technique for correcting settlement of buildings using a bracket.

JP 2007-100454 A JP 2007-182741 A JP 11-29953 A JP 2008-308856 A JP-A-8-27829

The conventional techniques described above have the following problems.
(1) The steel pipe joining techniques disclosed in Patent Documents 3 and 4 are complicated and difficult to perform on site. For example, “bolts and nuts” are used for joining steel pipes, but using other members increases the work load.
(2) The supporting force of the pile consists of “circumferential frictional resistance” and “tip supporting force”, but if “bolts and nuts” protrude from the joint of the steel pipe, the “peripheral frictional resistance” decreases and the pile Will weaken their supportive power.
(3) In Patent Document 5, since the bracket is finally embedded as it is (see FIG. 13), it is disposable.

Thus, the present invention provides an invention that can solve the problems of the conventional techniques and achieve the following objects.
(1) Less work burden on workers (work efficiency)
(2) The work load is small, but reliable construction is performed (high quality)
(3) Recycling of materials (specifically brackets) required for construction (low cost)

In order to achieve the above object, the first invention is a joint structure of a small-diameter steel pipe pile that is constructed by horizontally adding a small-diameter steel pipe and press-fitting to a solid ground in order to repair the building horizontally and prevent future subsidence. The steel pipe has a male joint at one end and a female joint at the other end joined to the male joint.
According to a second aspect of the present invention, there is provided a small-diameter steel pipe having an adjustable joint that can be stretched between a general steel pipe to be joined to a non-foundation side end of a pile head steel pipe in contact with a foundation of a building. This is a pile connection structure.
3rd invention is the joining structure of the said small diameter steel pipe pile characterized by joining of the steel pipe by the said joint by screwing.
A fourth invention is a bracket for joining a small-diameter steel pipe pile that has been joined to a solid ground by adding a small-diameter steel pipe in order to repair the building horizontally and prevent future subsidence. Has at least a fixed part to be attached to the steel pipe and a pedestal part that extends horizontally and can be installed with a jack. The bracket is a small-diameter steel pipe pile joint bracket characterized by being a split structure that can be divided in the small-diameter steel pipe pile direction with the fixed part as the center.
The fifth invention is a construction method for constructing a small-diameter steel pipe pile under the foundation of the building in order to restore the building horizontally and prevent future subsidence. The steel pipe having a small diameter is added by using the building as a reaction force. However, it has a general steel pipe joining process that press-fits to solid ground and a pile head steel pipe joining process that joins the foundation of the building and a small diameter steel pipe pile, and the general steel pipe connection process has a male joint at one end of the steel pipe The other end is equipped with a female joint that is joined to the male joint, and the steel pipes are joined together. The pile head steel pipe joining process begins with the end of the foundation of the small-diameter steel pipe pile before joining the pile head steel pipe Attach a bracket to the bracket pedestal, install a jack on the bracket base, prepare a small-diameter steel pipe pile formed by the jack and the pile head steel pipe adjusted in length, and prepare the small-diameter steel pipe pile and the pile head steel pipe Between the pile head steel pipe and the foundation Adjusted so no gap is then jack and construction method of the small-diameter steel pipe piles, characterized in that to remove the bracket.

The present invention has the following effects.
(1) By providing “male joints” and “female joints” at both ends of the steel pipes that make up the small diameter steel pipe piles, it is not necessary to join the steel pipes by “welding” at the site. Bonding becomes possible.
(2) Moreover, since the joint portion does not protrude from the outer periphery of the small-diameter steel pipe pile, it can be placed without disturbing the peripheral ground, and the bearing capacity of the pile can be increased without reducing the peripheral frictional resistance. Can be maintained.
(3) “Pile head steel pipe” to be finally joined to a small diameter steel pipe pile requires precise dimensional accuracy. By providing this pile head steel pipe with an adjusting function, the pile head steel pipe and the foundation can be securely and It becomes possible to join easily.
(4) By using “screwing” for joining steel pipes, reliable and easy joining becomes possible.
(5) Since the bracket is a divided structure, it can be removed from the small-diameter steel pipe pile, and can be reused without embedding the bracket that has been embedded as it is.
(6) With the construction method of small-diameter steel pipe piles using steel pipes with male and female joints at both ends, the steel pipes constituting the small-diameter steel pipe piles can be reliably and easily connected (the construction efficiency Improvement). In addition, by using the bracket of the divided structure for the construction method, it becomes possible to reuse the bracket embedded in the past (cost reduction, ecology).

Explanatory drawing which shows the "general steel pipe" which comprises a small diameter steel pipe pile. Explanatory drawing which shows the "pile head steel pipe" which comprises a small diameter steel pipe pile. Explanatory drawing which shows the joining process of the general steel pipe in the construction method of a small diameter steel pipe pile. The expanded sectional view which shows the junction part of the general steel pipe shown in FIG. Explanatory drawing which shows the joining process of the pile head steel pipe in the construction method of a small diameter steel pipe pile. The expanded sectional view which shows the junction part of the pile head steel pipe shown in FIG. The perspective view for explanation which shows the bracket for small diameter steel pipe pile joining.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing a “general steel pipe” constituting a small diameter steel pipe pile. “General steel pipe” means a steel pipe other than a steel pipe (pile head steel pipe) in contact with the foundation of a building among small diameter steel pipes constituting a small diameter steel pipe pile.
The general steel pipe 20 includes a male joint 24 at one end 22 and a female joint 26 at the other end 23 of a small-diameter steel pipe main body 21 (for example, a general structural carbon steel pipe: STK400). The male joint 24 and the female joint 26 are previously set in a factory and welded to the steel pipe main body 21. The male joint 24 is provided with a thread 25, and the female joint 25 is provided with a thread groove (not shown) corresponding to the thread 25, so that the male joint 24 and the female joint 26 can be joined by screwing. Yes.

FIG. 2 is an explanatory view showing a “pile head steel pipe” constituting a small diameter steel pipe pile. “Pile head steel pipe” refers to a steel pipe in contact with the foundation of a building among small diameter steel pipes constituting a small diameter steel pipe pile.
The pile head steel pipe 30 includes an adjustment joint 34 at one end 32 of a steel pipe main body 31 having a small diameter (for example, a general structural carbon steel pipe: STK400). In addition, since the other end 33 is in contact with the foundation of the building, no particular joint is provided. The adjustment joint 34 is a telescopic joint, and includes a female joint 35 and a male joint 37. The male joint 37 is provided with a first thread 38 and a second thread 39. The female joint 35 is welded (factory welded) to the one end portion 32 of the steel pipe main body 31 and is provided with a thread groove (not shown) corresponding to the first thread 38 of the male joint 37. Can be joined by screwing. The second thread 39 of the male joint 37 corresponds to the thread groove of the female joint 26 of the general steel pipe 20 shown in FIG. 1, and the male joint 37 (adjustment joint 34) and the female joint 26 can be joined by screwing. It has become.

Drawing 3 is an explanatory view showing the joining process of the general steel pipe in the construction method of a small diameter steel pipe pile.
FIG. 3A shows a process of installing a jack 80 under the foundation 70 and press-fitting (lower pile press-fitting) a small-diameter general steel pipe 20 serving as a lower pile using the building as a reaction force.
FIG.3 (b) is the process of adding the general steel pipe 20 (medium pile 41) used as a middle pile to the general steel pipe 20 (lower pile 40) press-fitted by the lower pile in said (a) (middle pile built-in). .
FIG.3 (c) is the process of joining the general steel pipe 20 (medium pile 41) used as a middle pile to the general steel pipe 20 (lower pile 40) used as a lower pile. In this joining, the male joint 24 and the female joint 26 of the general steel pipe 20 shown in FIG. 1 are joined by screwing, and FIG. 4 shows the joint portion in an enlarged sectional view. As shown in FIG. 4, the threaded portion 25 of the male joint 24 and the threaded groove 27 of the female joint 26 are screwed together to form a screw coupling portion 28, thereby forming a strong joint.
FIG.3 (d) is the process of installing the jack 80 under the foundation 70 like the said (a), and press-fitting (medium pile press-fit) the small diameter general steel pipe 20 used as a middle pile by making a building into reaction force. .

FIG. 5 is an explanatory view showing a joining process of a pile head steel pipe in a construction method of a small diameter steel pipe pile.
FIG. 5A shows a state in which a pile head steel pipe (upper pile) that is in contact with the foundation of the building is left and is pressed into the middle pile 41, and the bracket 50 is attached to the middle pile 41 and the jack 80 is attached to the pedestal 51 of the bracket 50. This is a process of temporarily receiving the foundation 70 by installing. At this time, the length between the middle pile 41 and the foundation 70 is measured, and the pile head steel pipe 30 which becomes an upper pile is cut according to the measured length.
FIG. 5B is a process of joining the pile head steel pipe 30 (upper pile 42) to be the upper pile to the middle pile 41. Joining of the middle pile 41 and the pile head steel pipe 30 (upper pile 42) is joining by screwing the adjustment joint 34 (male joint 37) and the female joint 26 of the pile head steel pipe 30 shown in FIG.

  FIG. 5C is a step of adjusting the level of the joint between the pile head steel pipe 30 (upper pile 42) joined to the middle pile 41 and the bottom of the foundation 70. This level adjustment will be described in detail with reference to FIG. As shown in FIG. 6, the adjustment joint 34 includes a female joint 35 and a male joint 37. The second thread 39 of the male joint 37 and the female joint 26 of the general steel pipe 20 serving as the intermediate pile 41 are screwed into the thread groove 27 to form a screw coupling portion 45. On the other hand, the male joint 37 is also provided with a first thread 37, and the first thread 37 is screwed into the thread groove 36 of the female joint 35 constituting the adjustment joint 34. The first thread 37 and the thread groove 36 are designed to be long in advance, and the length of the pile head steel pipe 30 (upper pile 42) is adjusted (adjusted) by adjusting the screwing width of both. It has a structure that can be done. Therefore, by using the adjusting function of the pile head steel pipe 30 (upper pile 42), a precise level in joining the pile head steel pipe 30 (upper pile 42) joined to the middle pile 41 and the foundation 70 below. Adjustment can be realized reliably and easily.

  FIG. 5 (d) shows that the level can be adjusted in the above (c), the joining of the pile head steel pipe 30 (upper pile 42) and the bottom of the foundation 70 is completed, the jack 80 and the bracket 50 are removed, and the small diameter steel pipe is removed. This is a process in which the construction of the pile 10 is completed. In addition, the bracket 50 can be a member that is detachable from the general steel pipe 20 by using a divided structure that can be divided in the direction of the small-diameter steel pipe pile 10 around the fixing portion attached to the general steel pipe 20.

FIG. 7 is a perspective view for explaining a small-diameter steel pipe pile joint bracket.
As shown in FIG. 5, the bracket 50 is attached to the intermediate pile 41 to join the pile head steel pipe 30, but conventionally, since the pile head steel pipe 30 is joined to the bracket 50 by welding, Even after the construction of the small-diameter steel pipe pile 10, it could not be removed and was embedded as it was. A small-diameter steel pipe pile joining bracket (hereinafter referred to as “bracket”) 60 shown in FIG. 7 is an example of a bracket that can be removed after construction of the small-diameter steel pipe pile 10 and can be reused.

  The bracket 60 includes a pedestal portion 61 for installing a jack (not shown), a support portion 62 for supporting the pedestal portion 61, and a fixing portion 63 for attaching to a general steel pipe (not shown). . The fixing portion 63 is provided with an opening 64 so as to penetrate a general steel pipe (not shown), and has a divided structure in which the opening 64 can be divided. By providing the opening 64, the pile head steel pipe (upper pile) can be joined directly to the general steel pipe (middle pile). Moreover, since the opening part 64 can be divided | segmented, it becomes detachable with respect to a general steel pipe (medium pile). Therefore, the bracket 60 can be removed after the construction of the small-diameter steel pipe pile, and can be provided as a reusable bracket.

  INDUSTRIAL APPLICABILITY The present invention can be widely used as a joining technique for small-diameter steel pipe piles in which a steel pipe is added to a solid ground in order to repair a building horizontally and prevent future subsidence.

10 Small-diameter steel pipe pile 20 General steel pipe 21 Steel pipe body 22 End (one end)
23 End (the other end)
24 Male joint 25 Thread 26 Female joint 27 Thread groove 28 Screw coupling part 30 Pile head steel pipe 31 Steel pipe main body 32 End part (one end part)
33 End (the other end)
34 Adjustment Fitting 35 Female Fitting (for Adjustment Fitting)
36 Thread groove 37 Male joint (for adjustment joint)
38 1st thread 39 2nd thread 40 Lower pile 41 Middle pile 42 Upper pile 45 Screw coupling part 50 Bracket 51 Base part 60 Bracket 61 Base part 62 Support part 63 Fixing part 64 Opening part 70 Base 80 Jack

Claims (2)

In order to restore the building horizontally and prevent future subsidence, it is a joint structure of small-diameter steel pipe piles that are joined to a solid ground by adding small-diameter steel pipes,
The one end of the steel pipe is provided with a male joint, the other end thereof is provided with a female joint to be joined to the male joint, and the joining of the steel pipe by the joint is by screwing ,
The opposite end of the pile head steel pipe in contact with the foundation of the building is provided with an adjustable joint that can be expanded and contracted between the steel pipe and the general steel pipe to be joined. The adjustable joint is composed of a female joint and a male joint. The female joint is welded to the opposite end of the pile head steel pipe and has a thread groove corresponding to the first thread provided on the male joint so that it can be joined by screwing with the male joint. The second thread provided so as to be continuous with the first thread can be joined by screwing with the female joint of the general steel pipe corresponding to the thread groove of the female joint of the general steel pipe to be joined with the pile head steel pipe. A small-diameter steel pipe pile joint structure characterized by In order to restore the building horizontally and prevent future uneven settlement, it is a construction method to construct a small diameter steel pipe pile under the foundation of the building,
General steel pipe joining process in which a small diameter steel pipe is added as a reaction force and pressed into a solid ground,
A pile head steel pipe joining process for joining the foundation of the building and a small diameter steel pipe pile,
The general steel pipe connection process includes a male joint at one end of the steel pipe, a female joint joined to the male joint at the other end, and joins the steel pipes together by screwing.
In the pile head steel pipe joining process, first, a bracket is attached to the foundation side end of the small diameter steel pipe pile before joining the pile head steel pipe, a jack is installed on the bracket pedestal, and a small diameter steel pipe pile formed by the jack. in so no gap, buildings between the pile head steel pipe and underlying joined with joining small diameter steel pipe piles and pile head steel pipe prepared pile steel pipe which has been adjusted length between the foundation and The end of the pile head steel pipe that contacts the foundation of the pile is provided with a telescopic adjustment joint between the steel pipe and the general steel pipe to be joined. The adjustment joint is composed of a female joint and a male joint. The female joint is welded to the opposite end of the pile head steel pipe and has a thread groove corresponding to the first thread provided on the male joint so that it can be joined to the male joint by screwing. The second thread provided to be continuous with one thread joins the pile head steel pipe That corresponds to the screw groove of the female joint of the general steel pipe of the same general steel pipe was adjusted by being enabled joined by a female fitting and screwing, the small-diameter steel pipe piles subsequently characterized by removing the jack and the bracket Construction method.

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