JP2002038872A - Hollow shield machine and widening method for tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow shield machine and a widening method for a tunnel, allowing the outer periphery of the existing tunnel to be smoothly widened and excavated and permitting a sufficient cut-off effect to be secured. SOLUTION: In the hollow shield machine 1, wherein a hollow part having approximately the same inside diameter as the outer periphery of the existing tunnel (a) is installed in an opened manner, an inner cylinder 2 is mounted between the outer periphery of the existing tunnel (a) and the inner periphery of the shield machine 1 and installed C without being fixed in a radial direction relative to the shield machine 1. Gaps on both sides are hermetically sealed with a seal member 3 and a flexible material 4, and a filler 5 is injected into a void part. In the widening method for the existing tunnel (a), inner-surface protecting construction is carried out by means of a protective member installed within the existing tunnel (a) while the shield machine 1 allows the outer periphery of the existing tunnel (a) to be widened and excavated in a doughnut shape, a new segment having a larger diameter than the existing tunnel (a) is assembled, and the existing tunnel (a) is supported on a supporting trestle installed within the new segment. After that, the existing tunnel (a) is removed for the purpose of constructing a new widened tunnel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hollow shield machine for widening an existing tunnel and a method for widening the tunnel.

[0002]

[Problems to be Solved by the Invention] It was in 1965 that shield tunnels began to be used in earnest as urban tunnels. Almost 30 years have passed since then, and the problem of aging has occurred in some parts, necessitating renewal. Conventionally, as a method of renewing an aging tunnel, for example, a method has been adopted in which an inner wall surface is demolished, an inner winding concrete or an inner winding support is provided, and a surrounding ground is improved from inside the tonnel. However, since many shield tunnels are designed and constructed with a minimum necessary inner space section in order to control costs during construction, it has been extremely difficult to repair and reinforce the tunnel interior.

On the other hand, for a large-sized tunnel, a method has been proposed in which a tunnel having a large cross section is newly constructed outside the tunnel, and thereafter, the deteriorated tunnel is dismantled. However, in order to remove the existing tunnel and build a new tunnel using the shield method, it was necessary to construct a new water-stop zone around the existing tunnel and make a lining body.
In addition, due to construction errors and aging, the segment itself,
Or, transverse deformation often occurs at the connection between the segments along the axial direction of the tunnel. Further, a backing material is injected between the tunnel segment and the ground. Therefore, when the shield machine advances, the seal member is easily torn, and it is difficult to secure a sufficient water stopping effect.
It was difficult to excavate the outer circumference of the existing segment smoothly.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to make it possible to excavate the outer periphery of an existing tunnel smoothly and to avoid breakage of a seal member. An object of the present invention is to provide a hollow shield machine. Still another object of the present invention is to provide a tunnel widening method capable of constructing a new widening tunnel by excavating the outer periphery of an existing tunnel.

[0005]

In order to achieve the above object, a hollow shield machine according to a first aspect of the present invention is a hollow shield excavator having a hollow portion having an inner diameter substantially the same as the outer circumference of an existing tunnel. In a shield machine, an inner cylinder is provided between the outer periphery of the existing tunnel and the inner periphery of the hollow shield machine, and the inner cylinder is installed without being fixed to the hollow shield machine in a radial direction. It is characterized by the following.

A hollow shield excavator according to a second aspect of the present invention is a hollow shield excavator in which a hollow portion having an inner diameter substantially the same as the outer periphery of an existing tunnel is opened. An inner cylinder is provided between the inner cylinder and the tunnel, and this inner cylinder is installed without being fixed in the radial direction with respect to the hollow shield machine, and a seal that seals a gap between the inner cylinder and the existing tunnel is provided. It is characterized by attaching members.

[0007] Further, the invention according to claim 3 of the present invention provides:
The hollow shield machine according to claim 1 or 2, wherein a flexible material is attached between the inner cylinder and the hollow shield machine.

A method for widening a tunnel according to a fourth aspect of the present invention is a widening method for widening an existing tunnel, wherein the hollow shield machine according to any one of the first to third aspects is provided. While using a hollow shield excavator to excavate the outer periphery of the existing tunnel in a donut shape while widening the tunnel, protect the inner surface of the existing tunnel with the protective member installed in the existing tunnel, and assemble a new segment with a larger diameter than the existing tunnel In addition, the existing tunnel is supported by a support frame installed in the new segment, the existing tunnel is removed, and a new widening tunnel is constructed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the hollow shield machine and the method of widening a tunnel according to the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

<A> Basic Configuration of Hollow Shield Excavator As shown in FIG. 1, a hollow shield excavator 1 is a cylindrical shield having a hollow portion having an inside diameter substantially the same as the outer periphery of an existing tunnel a to be constructed. It is an excavator. On the front surface thereof, a hollow donut-shaped disk is attached as an annular drilling disk 11. Inner circumference of this hollow shield machine 1 and existing tunnel a
The inner cylinder 2 is installed without being fixed to the hollow shield machine 1 in the radial direction between the outer periphery of the inner cylinder 2 and the outer periphery of the hollow shield machine 1. On both sides of the inner cylinder 2, seal members 3 for sealing the gap are attached. Further, a flexible member 4 is provided between the inner cylinder 2 and the hollow shield machine 1 (FIG. 3). Note that the seal member 3 does not always need to be provided between the inner cylinder 2 and the inner periphery of the hollow shield machine 1. Further, the flexible member 4 may be interposed between the inner cylinder 2 and the existing tunnel a. Hereinafter, each part will be described in detail.

<B> Hollow Shield Excavator Main Body The hollow shield excavator 1 main body, as shown in FIG. 2, excavates the outer periphery of an existing tunnel a having a circular cross section in an annular shape, and is formed in a cylindrical shape. It has an outer skin plate 17 and a cylindrical inner skin plate 18 installed inside the outer skin plate 17 at a predetermined interval. A cutting bit 11a is radially provided on the annular drilling disk 11 on the front surface. The annular excavating disk 11 is rotated by a motor 12 as shown in FIG. A shield jack 13, a mud feeding pipe 14, a mud discharging pipe 15, and a tail seal 16 are provided behind the excavating disk 11. Also, in order to reliably cut the backing material b injected on the outer peripheral portion of the existing tunnel a,
Inside the excavating disk 11, a cutter bit 11b as shown in FIG. The bit 11b cuts the backing material b without contacting the existing tunnel a by reciprocating the inner cylinder 2 described below in the radial direction with respect to the shield machine 1 (FIG. 3, 4).

<C> Inner cylinder The inner cylinder 2 is a ring-shaped cylinder formed of a steel material. As shown in FIG. 3, the inner cylinder 2 is formed between the outer periphery of the existing tunnel a and the inner periphery of the hollow shield machine 1 or the inner skin plate 18. Between them, they are not fixed in the radial direction but are installed by a known movable means such as a roller. Therefore, this inner cylinder 2 is a hollow shield machine 1
With the excavation, the robot can reciprocate in the radial direction within a predetermined allowable range. Thereby, even if the segments of the existing tunnel a, or the joints between the segments and the segments are deformed like irregularities, the hollow shield machine 1 (or the bit 11b) does not contact the existing tunnel a. In addition, the backing material b, earth and sand, etc. attached to the outer peripheral portion can be reliably cut, and the excavation can be safely advanced.

<D> Seal Member In FIG. 4, on both sides of the inner cylinder 2, seal members 3 are arranged in a ring shape. These sealing members 3
Each of them is made of a wire brush. Further, a water-stopping filler 5 is injected into a gap formed by the seal member 3 and the flexible member 4 described below. The filler 5 is made of grease, resin, or the like, passes through a filler supply device (not shown),
It is injected between the inner cylinder 2 and the outer periphery of the existing tunnel a. Further, a U-packing 6 for high-hydraulic pressure seal is disposed in front of the inner skin plate 18 and the inner cylinder 2. The space between the U packing 6 and the seal member 3 is also filled with the filler 5 so as to enhance the sealing performance. In this manner, the seal member 3, the U packing 6, and the filler 5 cooperate to prevent groundwater, backing material b, and earth and sand from entering the hollow shield machine 1. In the above embodiment, the seal members 3 are arranged on both sides of the inner cylinder 2, but are not limited to this, and need not be provided between the inner skin plate 18 and the inner cylinder 2.

<E> Flexible Materials On both sides of the inner cylinder 2, flexible materials 4 are mounted in several stages as shown in FIG. These flexible members 4 are formed of elastic ring-shaped bags, into which fluid such as air or water is injected at a predetermined pressure. Accordingly, these flexible members 4 are adapted to deform as the inner cylinder 2 reciprocates in the radial direction during excavation. This prevents the inner cylinder 2 from contacting the existing tunnel a, prevents the seal member 3 from being damaged, and prevents the filler 5 from flowing out. In the embodiment shown in FIG. 4, the flexible members 4 are disposed on both sides of the inner cylinder 2, but may be provided only between the inner cylinder 2 and the shield machine 1.

Next, a method of widening a tunnel by the hollow shield machine having the above configuration will be described.

<A> Installation of Hollow Shield Excavator First, the hollow shield excavator 1 is installed on the outer periphery of the existing tunnel a at a predetermined work base, for example, in a starting shaft. At this time, the inner cylinder 2 is inserted between the outer periphery of the existing tunnel a and the inner periphery of the hollow shield machine 1.
Install without fixing in the radial direction. And
The gap defined by the seal member 3 and the flexible member 4 provided on both sides of the inner cylinder 2 is filled with a filler 5 to seal the space therebetween, and when excavating, dirt, dust, and the like enter the shield machine from the front of the shield machine 1. To prevent foreign matter from entering. Further, while adjusting the pressure, water or air is injected into the flexible member 4 and the inner cylinder 2 is reciprocated in the radial direction to check the operation state.

<B> Inner surface protection of the existing tunnel At the time of widening excavation, inner surface protection for preventing deformation of the inner surface of the existing tunnel a or peeling-off of the lining is performed by using a protective material installed in the existing tunnel a. For example, as shown in FIG. 5, it is assumed that the truck 8 is moved to the tip of the excavation, and the protective frame 7 mounted on the truck is positioned and installed on the inner surface of the existing tunnel a. The protective frame 7 is
The protective members 7a and 7b made of a steel material such as an H-section steel are assembled at predetermined intervals to form an arc as shown in the figure. The protective frame 7 is installed by adjusting jacks 8a and 8b mounted on the trolley 8 so as to be aligned with the inner surface of the existing tunnel.
Has been firmly supported. The protective frame 7 can be removed from the existing tunnel a with the jacks 8a and 8b. Therefore, in order to install the protective frame 7 in a predetermined work section, the truck 8 moves in the forward and backward direction of the tunnel, and the jacks 8a and 8b mounted on the truck 8 in the lateral direction of the tunnel. Protecting work becomes easier by adjusting the position, and work efficiency is improved in spite of work inside the tunnel, and safe and reliable construction is possible.

<C> Excavation by Hollow Shield Excavator As shown in FIG. 5, the outer periphery of the existing tunnel a is excavated by the hollow shield excavator 1. In this cylindrical shield machine, a hollow portion having substantially the same inner diameter as the outer periphery of the existing tunnel a to be constructed is opened, and the hollow portion and the existing tunnel a
Between them, a ring-shaped inner cylinder 2 is provided without being fixed in the radial direction. When the annular excavating disk 11 is driven to rotate, the outer periphery of the existing tunnel a is excavated in a predetermined range in an annular manner. At this time, the inner cylinder 2 can reciprocate in the radial direction or the lateral direction of the tunnel with the advance of the shield excavator 1 in response to the own deformation of the deteriorated existing tunnel a, the construction error, and the like. As shown in FIG. 4, the seal member 3, the U-packing, the flexible member 4 and the filler 5 attached to both surfaces of the inner cylinder 2 cooperate to form the backing material b, the muddy water and the muddy hollow. The shield machine 1 is prevented from entering.

<D> Assembling of the new segment As shown in FIG.
It is carried out rearward via a mud pipe 14 inside. When the shield machine 1 is propelled by one pitch, the shield jack 13 is reduced and the new segment 91 is assembled in the excavated space of one pitch to construct the new widened tunnel 9 having a larger diameter than the existing tunnel a.

<E> External protection of the existing tunnel Between the new widening tunnel 9 and the existing tunnel a, as shown in FIG. 7, an external protection work for preventing the sinking or swinging of the existing tunnel a is performed. It is assumed that the protector supports the existing tunnel a from below by the support frame 10 so that the existing tunnel a does not sink. The support base 10
Consists of steel materials 10a and 10b such as H-section steel,
The size and position can be adjusted by a built-in jack or the like. Further, a plurality of support members 10c may be arranged at predetermined intervals in the circumferential direction so that the existing tunnel a does not swing.

When the assembling of the new segment 91 is completed by repeating the above operation, the existing tunnel a is removed while removing the support base 10 supporting the existing tunnel a from below. Then, the construction of the new widening tunnel 9 having a larger diameter than the existing tunnel a is completed.

[0022]

The hollow shield machine and the method for widening a tunnel according to the present invention are as described above, and the following effects can be obtained. <A> An inner cylinder is installed between the outer circumference of the existing tunnel and the inner circumference of the hollow shield machine without fixing the hollow shield machine in the radial direction, and the gaps on both sides of this inner cylinder are sealed. It is sealed with a member and a flexible material, and a filler is injected into a space defined by the sealing material and the flexible material.
Therefore, even if the existing tunnel is deformed, the inner cylinder reciprocates in the radial direction and follows the deformation,
The backing material on the outer periphery of the hollow shield excavator can be cut smoothly without contact with the existing tunnel, and sufficient waterproofness can be obtained without breaking the seal member. <B> While excavating the outer periphery of the existing tunnel in a donut shape with a hollow shield excavator, protect the inner surface of the existing tunnel with the protective members installed in the existing tunnel, and assemble a new segment with a larger diameter than the existing tunnel. After the existing tunnel is supported by the support base installed in the new segment, the existing tunnel is removed and a new widening tunnel is constructed. Therefore,
Compared with the prior art, it is not necessary to construct a new water stop zone around the existing tunnel, a sufficient water stop effect can be secured, and the widening work can be performed safely and reliably.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a working state of a hollow shield machine according to the present invention.

FIG. 2 is a longitudinal sectional view of a hollow shield machine according to the present invention.

FIG. 3 is a cross-sectional view of the hollow shield machine according to the present invention.

FIG. 4 is a partially enlarged view of the hollow shield machine of the present invention.

FIG. 5 is an explanatory view of a method for widening an existing tunnel according to the present invention.

FIG. 6 is an explanatory view of the inner surface protection of an existing tunnel.

FIG. 7 is an explanatory view of an outer surface protection work for an existing tunnel.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshimi Saito 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Shinichi Wakasa 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo No. Taisei Corporation F term (reference) 2D054 AA05 AA06 AC05 AD22 BA05 FA06 2D055 BA01 BB01 FB02 FB05

Claims (4)

[Claims] Claims: 1. A hollow shield machine having a hollow portion having substantially the same inner diameter as the outer periphery of an existing tunnel, wherein an inner cylinder is provided between the outer periphery of the existing tunnel and the inner periphery of the hollow shield machine. The hollow shield excavator is characterized in that the inner cylinder is installed without being fixed to the hollow shield excavator in the radial direction. 2. A hollow shield machine having a hollow portion having substantially the same inner diameter as the outer periphery of an existing tunnel, wherein an inner cylinder is provided between the outer periphery of the existing tunnel and the inner periphery of the hollow shield machine. The inner cylinder is installed without being fixed to the hollow shield machine in the radial direction, and a seal member that seals a gap between the inner cylinder and the existing tunnel is attached. Machine. 3. The hollow shield machine according to claim 1, wherein a flexible material is attached between the inner cylinder and the hollow shield machine. 4. A widening method for widening an existing tunnel, comprising using the hollow shield excavator according to any one of claims 1 to 3, wherein the hollow shield excavator is used to expand the existing tunnel. While supporting the inner surface of the existing tunnel with a protective member installed in the existing tunnel while excavating the outer circumference in a donut shape, assembling a new segment with a larger diameter than the existing tunnel, and installing the existing tunnel in the new segment The method of widening a tunnel, characterized by removing the existing tunnel and constructing a new widening tunnel after having been supported by.