JP2007146522A - Cavity filling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filling method which enables filling of a limited prescribed area of a cavity when the cavity on the back of a tunnel expands widely. <P>SOLUTION: The tunnel T is drilled by a proper construction method, and a support 5 is constructed across the inside of a tunnel pit. Then, a sheet pile 3 located near the bottom of the cavity V is holed to cause a strip-shaped bag 10 of a given length to project out toward the cavity V at the back of the support 5, and the mouth of the bag 10 is fixed to the support 5. An urethane foam is injected into the bag 10 to inflate the bag 10 by foaming to form a buffering material 1 having a given length and a given diameter in a prescribed area R of the cavity V. Subsequently, the buffering materials 1 are constructed continuously from both side walls toward the top end of the tunnel T in the prescribed area R of the cavity V to build a buffering zone made up of a bundle of the buffering materials 1 in the prescribed area R of the cavity V. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for filling cavities, and more particularly to a method for filling cavities existing on the back of a tunnel in a limited manner.

Conventionally, in tunnel excavation work or repair work for existing tunnels, it has been attempted to reinforce the ground on the back of the tunnel by filling a cavity in the back of the tunnel (for example, Patent Documents 1 to 3). See).
Japanese Patent No. 3447529 Japanese Patent No. 3447530 Japanese Patent No. 3492501

  In tunnel excavation in the old mining area, abandoned mine shafts that meet the mining site may be encountered or the vicinity of the abandoned shaft shafts may be excavated. In such a case, if a large cavity such as an abandoned tunnel is completely filled, it takes a work period and a construction cost. Therefore, it is desired to fill the cavity in a limited range. However, when the cavity is greatly expanded, the filling material is scattered by the conventional filling method as described in Patent Documents 1 to 3, and it is difficult to fill the predetermined range of the cavity in a limited manner.

  The present invention has been made in view of the above-described problems, and provides a filling method capable of filling a predetermined range of cavities in a limited manner when the cavities existing on the back surface of the tunnel are greatly expanded. With the goal.

In order to achieve the above-mentioned object, the present invention is a method for filling a cavity existing on the back of a tunnel in a limited manner, in a bag body having a predetermined length protruding from the tunnel support toward the cavity. The operation of forming the buffer body by filling the filler material is sequentially performed from the tunnel side wall portion toward the top end portion, and a buffer zone made up of the bundle of buffer bodies is formed in a predetermined range of the cavity. To do.
In the present invention, since the buffer body formed by filling the inside of the bag having a predetermined length with the filler is arranged in a bundle in the predetermined range of the cavity, if the partition wall or the like is not built in the cavity, the filling in the cavity will be performed. Even in the case where the cavity is greatly expanded, which is impossible, it is possible to fill the predetermined range of the cavity in a limited manner. In addition, since the bunch of buffer bodies catches the falling rocks from the upper part of the cavity, it also functions as a falling rock protection work.

In the present invention, it is preferable that the filler is urethane foam.
Urethane foam has a very large amount of deformation after yielding and is excellent in impact resistance. Moreover, since it is excellent also in durability, since it can inject | pour into a bag body using an injection tube, construction is also easy.

Moreover, in this invention, it is suitable for the said bag body to provide a core material in the said bag body.
By arranging the core material in the bag body, the bag bodies are not entangled with each other, and the filling work of the filler material becomes easy.

  In the cavity filling method according to the present invention, the cushioning bodies formed by filling a bag having a predetermined length with a filler are arranged in a bundle within a predetermined range of the cavity, so that even when the cavity is greatly expanded A predetermined range of the cavities can be limitedly filled.

Hereinafter, a cavity filling method according to the present invention will be described with reference to the drawings.
1 to 3 are plan sectional views in the direction perpendicular to the tunnel axis for explaining the present filling method. Here, the case where a tunnel is built in the lower part of an abolished mine so that it may intersect with an abolished mine will be described.

First, the tunnel T is excavated by an appropriate method, and the support work 5 is installed in the mine. The support 5 is composed of an arch-shaped steel support 2 disposed in a direction perpendicular to the tunnel axis at a predetermined interval in the tunnel axis direction and shotcrete 4.
In the abandoned tunnel (hereinafter referred to as “cavity V”), since there is no natural ground G above the tunnel T, the supporting work 5 need not be installed. For supporting the falling rock from the upper part of the cavity V, and the belt-like sheet pile 3 spanned between the steel support 2 and 2 The supporting work 5 consisting of is installed.

Next, by making a hole in the sheet pile 3 located near the bottom of the cavity V, the belt-shaped bag body 10 having a predetermined length is projected toward the cavity V on the back surface of the support work 5, and the mouth portion of the bag body 10 is Fix to support 5.
Here, as the bag body 10, a cloth packer (grouting jacket), a cloth formwork (concrete mat), or the like can be used.

  Then, foamed urethane is injected into the bag body 10 so as to expand and expand, and the buffer body 1 having a predetermined length and a predetermined diameter is formed in the predetermined range R of the cavity V. Incidentally, the buffer body 1 in the present embodiment has a cylindrical shape having a diameter of about 600 mm and a length of about 3000 mm.

FIG. 4 shows a method of injecting the urethane foam 14 into the bag body 10.
A rod-shaped core material 12 having substantially the same length as the bag body 10 is inserted into the bag body 10, one end of the core material 12 is fixed at the mouth portion 11, and a diameter-enlarged portion 12 a is formed at the other end. Is formed. The injection tube 13 is inserted into the bag body 10 from the mouth portion 11 and the foamed urethane 14 is discharged from the injection tube 13 to fill the bag body 10 with the foamed urethane 14.

  The foaming ratio of the foamed urethane 14 is 30 to 50 times, the gel time (time until fluidity is lost) is about 1 to 2 minutes, and the foam V is rapidly cured in the cavity V. Further, the strain after yielding is very large as about 5 to 80%, and the impact due to falling rocks from the upper part of the cavity V can be easily absorbed. In addition, it is excellent in durability and can be injected into the bag body 10 using the injection tube 13, so that construction is easy.

  Now, when the buffer body 1 is formed near the bottom of the cavity V, the bag body 10 protrudes toward the cavity V on the back of the support work 5 by making a hole in the upper sheet pile 3 or the like. The mouth part of is fixed to the support work 5. Then, foamed urethane is injected into the bag body 10 so as to expand and expand, and a buffer body 1 having a predetermined length and a predetermined diameter is newly formed above the already formed buffer body 1.

  The above procedure is sequentially performed from the both side wall portions of the tunnel T toward the top end portion, and a buffer zone composed of a bundle of buffer bodies 1 is formed in a predetermined range R of the cavity V.

  In the cavity filling method according to this embodiment, the shock absorbers 1 formed by injecting the urethane foam 14 into the belt-like bag body 10 having a predetermined length are arranged in a bundle in the predetermined range R of the cavity V. Even in the case where the cavity V is greatly expanded so that the interior of the cavity V cannot be filled unless a partition or the like is constructed in the V, the predetermined range R of the cavity V can be limitedly filled. Moreover, since the bundle of the buffer bodies 1 receives the falling rocks from the upper part of the cavity V, it also functions as a falling rock protection work.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit thereof. For example, in the above-described embodiment, the core member is a rod-shaped member, but is not limited to this, and may have another shape such as a spiral shape. The point is that the desired function can be obtained in the present invention.

It is a plane sectional view of a tunnel axis orthogonal direction for explaining a filling method of a cavity concerning the present invention. It is a plane sectional view of a tunnel axis orthogonal direction for explaining a filling method of a cavity concerning the present invention. It is AA arrow sectional drawing in FIG. It is explanatory drawing which showed the method of inject | pouring foaming urethane in a bag body, (a) is a state before foaming urethane injection, (b) is the state at the time of foaming urethane injection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Buffer 2 Steel support 3 Sheet pile 4 Shotcrete 5 Support 10 Bag body 11 Mouth part 12 Core material 12a Expanded diameter part 13 Injection pipe 14 Urethane foam T Tunnel V Cavity R Predetermined range G Ground

Claims (3)

It is a method of filling the cavities existing on the back of the tunnel limitedly,
The operation of forming a buffer body by filling the inside of the bag body having a predetermined length projecting from the tunnel support work toward the cavity is performed from the tunnel side wall portion toward the top end portion, A method for filling a cavity, wherein a buffer zone comprising a bundle of the buffer bodies is formed in a predetermined range of the cavity.   The method for filling a cavity according to claim 1, wherein the filler is urethane foam.   The method for filling a cavity according to claim 1, wherein the bag body includes a core material in the bag body.

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