JPH10140974A - Device for sealing arrival opening of tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety and reduce the construction period at the same time, by increasing the impervious function and remarkably reducing the working load of labors. SOLUTION: A conical ring body 2 whose maximum diameter is sufficiently larger than a tunnel diameter and whose minimum diameter is sufficiently smaller than the tunnel diameter is embedded in an expected arrival position of the tunnel of an earth-retaining wall body 1 in such a posture that the diameter is increased toward the ground, to constitute the sealing device of the arrival opening of the tunnel. The conical ring body 2 is formed of a laminate body of a steel layer and a rubber layer contacting the inside of the steel layer and including a hygroscopic and expansible resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a tunnel digging method using a shield method, in which an excavator arrives at a connection point with an existing tunnel, a shaft provided at an intermediate point of tunnel construction, or a wellhead position at an end point. Sometimes, the present invention relates to a device for sealing a gap between a retaining wall provided at such an arrival point and a tunnel excavator fitted into the retaining wall.

[0002]

2. Description of the Related Art When a tunnel is excavated by a shield method, a wellhead must be provided on a retaining wall provided at a point where the tunnel is to be reached, and the tunnel must be connected to the tunnel body. Then, when connecting the tunnel wall, which is provided as a lining to protect the tunnel from earth pressure, spring water, etc., and the retaining wall, accidents such as inflow of sediment and flooding may occur. There was danger.

Conventionally, as shown in FIG. 5, before the tip of the tunnel 4 reaches the retaining wall 1, a solidifying chemical is injected into the ground E behind the retaining wall 1 in advance. The ground is stabilized by the method, and the stabilized zone G is excavated by the shield type tunnel excavator 3 so that the tunnel 4 reaches the back surface of the retaining wall 1. The water stopping process is performed by filling a water stopping material or the like between the lining 4a of the inner wall and the outer surface of the shield. Thereafter, the retaining wall 1 is cut from the surface side to form an opening having substantially the same diameter as the tunnel.
After exposing the front of the excavator 3, the excavator 3 is penetrated into the retaining wall 1, and the devices inside the shield are disassembled and carried out. A method has been mainly adopted in which the connection between the earth retaining wall body 1 and the tunnel body 4 is completed by coupling and further lining the inner surface of the shield tube 3a.

In such a conventional method, the ground behind the retaining wall must be stabilized over a wide range by a method such as injection of a chemical solution. This required a large amount of money, including confirmation of the effects of ground stabilization, and the prevention of accidents was not perfect. In addition, the amount of work required to form an opening in the earth retaining wall is large,
There was also a problem that a lot of labor and a long construction period were required.

The inventor of the present invention has proposed an improved method of connecting a retaining wall body and a tunnel reaching part which can solve the above-mentioned drawbacks, in which the diameter increases toward the ground and the minimum diameter is smaller than the tunnel diameter. Constructing an earth retaining wall in which a sufficiently small conical ring is buried at a position expected to reach the tunnel with fiber-reinforced concrete being filled at least inside the ring; and A step of digging a tunnel to the expected tunnel arrival position of the retaining wall body and reaching the shield cylinder of the tunnel excavator to a position penetrating at least a part of the conical ring;
Excavating the earth retaining wall from the surface side to expose at least a front end of the shield cylinder, and coupling the shield cylinder and the conical annular body or a reinforcing material in the earth retaining wall body. And a patent application has been filed (JP-A-8-93382).

[0006]

However, even in such an improved technique, the present invention has been limited in view of the fact that there is a limit to the reduction of water stoppage work and filing work when removing the earth retaining wall in front of the tunnel excavator. An object of the present invention was to provide an improved tunnel sealing system for tunnel entrances, which can enhance the water stopping function, significantly reduce the amount of manual work, and simultaneously achieve improved safety and shortened construction period.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a conical ring whose maximum diameter is sufficiently larger than the tunnel diameter and whose minimum diameter is sufficiently smaller than the tunnel diameter. The conical ring is formed from a laminate of a steel layer and a rubber layer containing a water-absorbing expansible resin in contact with the inside of the steel layer. This can be achieved by a sealing device for a tunnel arrival wellhead.

[0008] In the device of the present invention, the rubber layer may be composed of an outer hard rubber portion and a seal body portion containing a water-absorbable resin and in contact with the inner side of the hard rubber portion.
Alternatively, it comprises an outer hard rubber portion having an annular fold toward the center of the conical annular body on the inside, and a seal body portion containing a water-absorbent resin and filling the space between the annular folds complementarily,
Or, it is composed of an outer hard rubber portion having an annular fold toward the center of the conical annular body on the inside, and a seal body portion formed of a water-absorbent resin and filling the gap between the annular folds complementarily. Is preferable.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a sealing device for a tunnel reaching a tunnel according to the present invention. The earth retaining wall 1 in the sealing device of the tunnel entrance of the present invention is, for example, a wall containing a reinforcing bar 1a provided around a working space at the bottom of a vertical shaft formed at an intermediate point of the tunnel. And
A conical annular body 2 having a maximum diameter sufficiently larger than the tunnel diameter and a minimum diameter, particularly an inner diameter sufficiently smaller than the tunnel diameter, is provided on a portion of the retaining wall body 1 where the tunnel is to be reached. Is built in such a manner that it is buried in advance in a site where the tunnel is to be reached. At least the inside of the conical annular body 2 is filled with concrete reinforced with fibers 1b such as stainless steel fiber, instead of using concrete reinforced with the reinforcing bar 1a. Therefore, the shield tunnel excavator
The fiber-reinforced concrete portion of the retaining wall can be easily excavated while penetrating into the retaining wall.

The conical ring 2 is formed by laminating an outer steel plate 2a and an inner rubber layer 2b. In the example of FIG. 2, such a rubber layer 2 b has a layered hard rubber portion 2 bh bonded to the steel plate 2 a on the outside, and protrudes toward the center of the conical ring body on the inside. , An annular fold 2w is formed. And this hard rubber part 2
bh, a sealing member 2b containing a water-swellable resin
s is provided, and a fold 2w 'having a shape complementary to the above-mentioned annular fold 2w is formed outside the seal body 2bs so as to fit with the fold 2w of the hard rubber portion 2bh. The space between them is filled. The rubber layer 2 in the example of FIG.
b is a hard rubber portion 2b whose outside is bonded to the steel plate 2a
h, the inside of which is a layer of the seal body portion 2bs containing the water-absorbable resin dispersed therein.

The water-swellable resin constituting the seal portion 2bs is, for example, a water-absorbent resin such as a cross-linked acrylic resin or a cross-linked polyvinyl alcohol resin, a water-soluble polymer or the like, a cross-linkable resin or rubber. It may be a known water-swelling resin material such as a water-absorbing rubber obtained by mixing and cross-linking, as long as it can maintain high gel strength even when the volume is expanded by absorbing water.
It can be used without restriction. Therefore, such a water-swellable resin material itself has flexibility similar to rubber, and if it is a solid material that can be cut, regardless of whether or not a rubber-like binder or a matrix resin is used in combination.
It can be used as it is as a material for forming the seal body 2bs in the above embodiment.

The shield tunnel excavator 3 advances toward the retaining wall 1 having such a structure, excavates the ground E which has not been subjected to the stabilization process, and reaches the back surface of the retaining wall 1. . When the tunnel excavator 3 enters the fiber-reinforced concrete portion of the retaining wall 1 as it is, the shield cylinder 3 a comes into contact with the conical ring 2.
Then, as shown in FIG. 4, the shield excavator 3 cuts off the sealing body 2bs of the conical annular body 2 and then also cuts off the hard rubber layer 2bh. At this time, if the water pressure in the ground is high, Penetrates along the shield cylinder 3a to the inside of the conical annular body 2. Then, the water comes into contact with and is absorbed by the seal body 2bs, and the seal body 2bs expands to seal the gap with the shield cylinder 3a, so that further inflow of water and earth and sand is prevented.

[0013] When the tunnel excavator 3 is further advanced, it penetrates the conical annulus 2 and the sealing by the expansion of the sealing body 2bs is further strengthened.
Eventually, the tunnel excavator 3 penetrates the retaining wall 1. At this time, if the water stoppage is not complete, a solidified liquid chemical for water stoppage can be injected into the ground E behind the retaining wall 1 through the chemical liquid injection pipe 1c as necessary.

After confirming that there is no water leakage, and after the front surface of the tunnel excavator 3 is exposed on the surface side of the retaining wall 1, the excavating device is disassembled from the inside of the shield tube 3a and carried out. The shield tube 3a and the earth retaining wall 1 are fixed by a method such as joining by welding and sealing with concrete, and the same lining as the inner wall of the tunnel 4 is applied.
The connection between the retaining wall 1 and the tunnel 4 is completed.

[0015]

According to the sealing apparatus for a tunnel reaching port of the present invention, the earth retaining wall can be excavated by the tunnel excavator without performing the stabilization process on the ground behind the earth retaining wall. In such a case, it is possible to automatically prevent water from flowing out and earth and sand from flowing out, so that the work of removing the retaining wall from the surface side can be omitted. Therefore, the construction is greatly safe, the construction period can be shortened, and the need for a ground stabilizing agent is eliminated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a sealing device for a tunnel reaching well according to the present invention.

FIG. 2 is a side view in which a part of a conical ring used in the sealing device for a tunnel entrance of the present invention is partially cut away.

FIG. 3 is a side view of another example of a conical ring used in the sealing device of the tunnel entrance of the present invention in a partially cut-out state.

FIG. 4 is an explanatory diagram showing a state in which a retaining wall provided with a sealing device for a tunnel arrival wellhead according to the present invention is excavated by a tunnel excavator.

FIG. 5 is an explanatory view of a connection method between a retaining wall body and a tunnel reaching part according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Retaining wall 1a Reinforcing bar 1b Stainless fiber 1c Chemical injection pipe 2 Conical ring 2a Steel plate 2b Rubber layer 2bh Hard rubber portion 2w Fold 2bs Seal body 2w 'Fold 3 Tunnel excavator 3a Shield cylinder 4 Tunnel 4a E Ground G Stabilized zone

Claims (4)

[Claims] 1. A conical annular body whose maximum diameter is sufficiently larger than the tunnel diameter and whose minimum diameter is sufficiently smaller than the tunnel diameter is scheduled to reach the retaining wall body in a posture in which the diameter increases toward the ground. The conical ring is formed from a laminate of a steel layer and a rubber layer containing a water-absorbing expansible resin in contact with the inside of the steel layer. Sealing device. 2. The tunnel arrival well according to claim 1, wherein the rubber layer comprises an outer hard rubber portion and a seal body portion containing a water-absorbable resin and in contact with the inside of the hard rubber portion. Sealing device. 3. The rubber layer comprises an outer hard rubber portion having an inner annular fold toward the center of a conical annular body on the inner side, and a space between the annular folds including a water-swellable resin and complementarily filled between the annular folds. The sealing device for a tunnel reaching well according to claim 1, wherein the sealing device comprises: 4. The rubber layer is formed of a water-absorbent resin and has an outer hard rubber portion having an inner annular fold toward the center of a conical annular body, and the space between the annular folds is complementarily filled. The sealing device for a tunnel reaching well according to claim 1, wherein the sealing device comprises: