JPH10252057A - Method for reinforcing foundation of structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reinforce a foundation using piles excellent in the strength of their connections, through a simple operation not requiring operators special for welding. SOLUTION: A new footing part 14 is added to the footing part 8 of the pier 6 of a speedway 2, and reinforcement is achieved using steel pipe piles 16. To construct the steel pipe piles 16, holes 20 are first excavated vertically by an excavator. Also, a number of short steel pipes 18 are prepared. The steel pipe 18 has an externally threaded part formed at one longitudinal end and has an internally threaded part at the other. In a vertically narrow space S below the base course 4, the externally and internally threaded parts at the ends of the steel pipes 18 are engaged with each other, and as the steel pipes 18 are sequentially extended they are inserted into the holes 20, with the desired length achieved by the number of steel pipes 18 coupled together by the threads, so that the steel pipe piles 16 are constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reinforcing a foundation of a structure, and more particularly, to a method of reinforcing a foundation of a structure by newly adding a reinforcing pile at a place where vertical space on the ground is limited. The present invention relates to a method for reinforcing a foundation of a structure suitable for reinforcing.

[0002]

2. Description of the Related Art For the purpose of improving seismic performance, it is known to add a new pile to an existing structure having a direct foundation or a pile foundation and reinforce the foundation. In this case, since the foundation of the existing structure is reinforced, the place of the pile driving work is often significantly restricted. For example, when reinforcing the foundation of a densely built building such as an office building with new piles, it is not possible to take space around the building, so drill holes in the ground from the basement of the building, In addition, a stake must be driven into the hole from this basement. In addition, when reinforcing the footing of the elevated road pier with a new pile, in places where the vertical space between the footing part and the roadbed is small, holes are excavated in the ground from the place where the vertical space is small,
A stake must be driven into the hole. For this reason, conventionally, a large number of short steel piles are prepared, and after excavating a hole, the pile is inserted into the hole while joining the ends of the pile by welding.

[0003]

For this reason, in the conventional method, since the pile is inserted into the hole while being joined by welding, a worker specializing in welding is required, and the work becomes complicated. . In addition, since the joining is performed by welding, there is a limit in increasing the strength of the joining portion of the pile. The present invention has been devised in view of the above circumstances, and an object of the present invention is to make it possible to reinforce a foundation with a pile excellent in strength of a connecting portion by a simple operation without requiring a welding specialist. It is to provide a method.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for reinforcing a foundation of a structure by newly adding a reinforcing pile at a place where vertical space on the ground is limited. After preparing a large number of short steel pipes having a male screw part at the end and a female screw part at the other end, and excavating holes in the ground from the place where the vertical space was restricted, the vertical space was restricted. The steel pipe is inserted into the hole while screwing the steel pipe to each other by screwing the male screw part and the female screw part at a location, thereby forming a steel pipe pile.

[0005] In the present invention, no welding specialist is required,
The steel pipe can be efficiently inserted into the hole while being added by screw connection. Further, the steel pipe can be mechanically added by using an excavator for excavating a hole for inserting a pile. In addition, by increasing the length of the male screw portion and the female screw portion, the foundation can be reinforced by a steel pipe pile having excellent strength at the joint portion of the steel pipe.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the case where the present invention reinforces the foundation of a pier on a highway will be described. 1 is a plan view of a footing portion of a pier on an expressway, FIG. 2 is a front view of the same section, and FIG. 3 is a sectional view of a main part of a steel pipe. 1 and 2, reference numeral 2 denotes an expressway, 4 denotes a roadbed, 6 denotes a pier, 8 denotes a footing portion, and a footing portion 8 is formed in a rectangular shape. A pillar 10 of a pier is erected in the center of the footing portion 8. And pillar 1
Existing stakes 12 are provided at eight locations below and on both sides of the footing portion. Reinforcement of the pier 6 is performed by adding a new footing portion 14 and a pile 16 that are added on both sides of the footing portion 8.
Made by The type of the existing pile 8 may be any type such as a support pile, a friction pile, a ready-made concrete pile, a cast-in-place concrete pile, and a steel pile. The pile 16 is a steel pipe pile, and is formed by connecting a number of short steel pipes 18 by screw connection.

[0007] In constructing the steel pipe pile 16, first, a hole 20 is excavated vertically by an excavator. In this case, hole 2
The vertical dimension of the space S from the ground where the ground 0 is excavated to the lower surface of the roadbed 4 is, for example, 2 to 3 m.
A hole 20 is drilled at a depth of, for example, 20 to 30 m. Also, a number of short steel pipes 18 are prepared. The steel pipe 18 has a length of, for example, 1 to 2 m and a diameter of 100 to 300 mm, and a so-called micropile is used. As shown in FIG. 3, the steel pipe 18 has a male screw portion 22 at one end in the longitudinal direction and a female screw portion 24 at the other end.

Next, the steel pipe 18 is vertically inserted into the hole 20. In detail, in the space S, the male screw part 22 and the female screw part 24 at the end of the steel pipe 18 are screwed together,
8 are inserted into the holes 20 while sequentially adding. In this case, the connection between the male screw portion 22 and the female screw portion 24 is performed by using an excavator that rotationally drives a drill or the like, thereby forming the space S.
Within a short period of time without human intervention. Then, the steel pipe pile 16 is formed to have a desired length by a number of screwed steel pipes 18. After the three steel pipe piles 16 are formed in this manner, the footing portion 14 is provided thereon, and the foundation of the pier 6 is reinforced. The outer peripheral surface of the steel pipe 18 may be inserted into the hole 20 while grouting the outer peripheral surface of the steel pipe 18 or inserting the grout into the hole 20 and then inserting the steel pipe 18 into the hole 20. Filling the gap between the surface and the wall surface of the hole 20 with grout increases the frictional force of the steel pipe pile 16 against the ground, and filling the grout inside the steel pipe 18 increases the strength of the steel pipe pile 16. Can be

Therefore, according to the present embodiment, it is possible to add the steel pipe 18 to the hole 20 while adding the steel pipe 18 in the vertically narrow space S without the need for a welding specialist and without complicating the addition work. We can insert well.
In addition, using an excavator that excavates a hole for inserting a pile,
Since the replenishment of the steel pipe 18 can be performed mechanically, the steel pipe 18 can be efficiently replenished without carrying several kinds of power machines into the narrow space S vertically. In addition, by increasing the lengths of the male screw portion 22 and the female screw portion 24, it is possible to sufficiently increase the strength of the joint portion of the steel pipe 18 as compared with welding.

In the embodiment, the case where the footing portion of the pier of the elevated road is reinforced is described. However, when the foundation of a building such as an office building is reinforced from the underground room, the foundation is reinforced from a place where the vertical space is limited. Applies to all cases of reinforcement.

[0011]

As is clear from the above description, the present invention
When newly adding a reinforcing pile at a place where the vertical space on the ground is limited, prepare a large number of short steel pipes having a male screw portion at one end and a female screw portion at the other end, After excavating a hole in the ground in the vertical space, the steel pipe is inserted into the hole while screwing the steel pipes together by screwing the male screw portion and the female screw portion in the vertical space. Therefore, it is possible to efficiently insert steel pipes into holes while adding steel pipes in narrow spaces limited vertically, without the need for welding specialists and without complicating the addition work. By using an excavator to excavate the steel pipe, the steel pipe can be mechanically added, thereby efficiently adding the steel pipe. In addition, by increasing the length of the male screw portion and the female screw portion, the strength of the joint portion of the steel pipe can be improved. Can be sufficiently increased. Therefore, to reinforce the foundation of a densely built office building or other building, it is necessary to drill a hole in the ground from the basement of the building and drive a pile into the hole from the basement, When reinforcing the footing portion of the pier, the present invention is suitable when, for example, it is necessary to excavate a hole from a place with a small vertical space below the roadbed and drive a pile into the hole.

[Brief description of the drawings]

FIG. 1 is a plan view of a footing portion of a pier on an expressway.

FIG. 2 is a sectional front view of a footing portion of a pier on an expressway.

FIG. 3 is a sectional view of a main part of a steel pipe.

[Explanation of symbols]

 2 Expressway 6 Bridge pier 8, 14 Footing part 16 Steel pipe pile 18 Steel pipe 20 hole 22 Male thread part 24 Female thread part

Claims (1)

[Claims] 1. A male thread part at one end and a female thread part at the other end when reinforcing a foundation of a structure by newly adding a reinforcing pile at a place where the vertical space on the ground is limited. After preparing a large number of short steel pipes having formed therein, excavating holes in the ground from the place where the vertical space is restricted, the steel pipes are screwed together by screwing the male screw part and the female screw part in the place where the vertical space is restricted. A steel pipe is inserted into the hole while screw-connecting the steel pipe, thereby forming a steel pipe pile, thereby reinforcing the foundation of the structure.