JPH10280868A - Tunnel section variable device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a section having a large connecting or branching part with a simple structure by arranging an air bag on the back surface of a skin plate and a support board protruded outward on the bottom surface thereof, and arranging a concrete placing pipe along a tail plate. SOLUTION: When a shield excavating machine 1 reaches an excavating section extending area, the moving jack of a cutter head 7 is extended to enlarge and excavate the excavating section. A support board 4 arranged on the bottom surface of a skin plate 2 is protruded to the outside of the plate 2, and grounded on the excavating section to balance and support the excavating machine 1. When the excavating machine 1 is passed through the extending area, the head 7 part is returned to the general state, and the excavating machine 1 is stably held in the extending area by the expansion of an air bag 3 and the support by the support board 4. Then, concrete 8 is filled from a concrete placing pipe 6 to the space part between a segment back surface and the bedrock, and the turning into the excavating machine 1 is prevented by the bag 3. Thus, the segment is removed after hardening, and the concrete surface is cut, whereby a tunnel, section can be constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for changing the size of a tunnel section during excavation.

[0002]

[Prior Art] Excavating underground by shield method, etc.
When installing power lines, installing water and sewage systems, and constructing roads, railways, and the like, it is often the case that a connection portion for cables and pipes, a junction, a branch point, a shelter, and the like are provided in an intermediate portion of these extensions. When excavating underground by shield method,
The size of the excavated cross section could not be changed on the way, and a pit was installed each time. However, according to this method, both the construction period and the construction cost are enormous, and an improvement measure has been desired.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has a simple structure.
Provided is a tunnel cross-section variable device and a method for changing a cross-sectional area during excavation and easily constructing a large cross-section at a middle part of excavation extension for a connection portion of a cable or a pipe, a junction, a branch point, a shelter, etc. The purpose is to do.

[0004]

Means for Solving the Problems A digging section changing device for digging a shield tunnel and changing the digging section during the digging, wherein an airbag is arranged on the back of the skin plate of the shield digging machine, At the bottom of the plate, a support plate protruding outward from the skin plate is installed, concrete casting pipes are arranged along the tail plate end of the shield machine, and the cutter head is slidable. Tunnel cross-section variable device, and also a tunnel cross-section variable device characterized in that an air bag is arranged on the back of the skin plate and the segment back of the shield excavator, also excavated the shield tunnel, during the excavation A tunnel section changing method for changing an excavated section, wherein a shield machine is provided in an excavated section enlarged section. At that point, the cutter head is enlarged and excavated, the support plate is extended below the enlarged excavation space, and the airbag on the back of the skin plate is inflated. Filling concrete sequentially, removing the segment after the hardening of the hardened concrete, shaving off the surface of the hardened concrete, and constructing a predetermined tunnel cross section is a tunnel cross section variable method.
Assemble the segment with the air bag on the back of the segment, inflate the air bag on the back of the segment and the air bag on the back of the skin plate at the same time, and from the back of the enlarged excavation space toward the digging direction, surround the air bag on the back of the segment. After the concrete is filled and the filled concrete is hardened, the tunnel section variable method is characterized in that a segment of the enlarged excavation section is removed and a predetermined tunnel section is constructed. Before reaching, the excavated section enlarged section is ground improved, and when the shield machine reaches the excavated section enlarged section, the cutter head is enlarged and excavated. Fill concrete sequentially from the back, behind the enlarged excavation section, in the direction of excavation. And, after curing the filling concrete, remove the segment of the expansion excavation section, the filling concrete surface 斫Ri a tunnel section variable method characterized by constructing a predetermined tunnel section.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

<A> Basic Configuration FIG. 1 is a longitudinal sectional view showing a basic configuration of a tunnel section varying device according to the present invention. The shield machine 1 provided with the tunnel section variable device includes an airbag 3 disposed on the back of the skin plate 2, a support plate 4 installed at the bottom surface of the skin plate 2 so as to be able to protrude outward from the skin plate 2,
The shield excavator 1 includes a concrete casting pipe 6 disposed along an end of a tail plate 5 of the shield machine 1 and a cutter head 7 configured to be slidable in a diameter direction.

<B> Air Bag The air bag 3 is previously installed over the entire back surface of the skin plate 2 at the face side and at the two rear surfaces at the end of the tail plate 5. At the time of installation, the airbag 3 is in a folded state, and is configured to be inflated when necessary by, for example, compressed air. The air bag 3 installed at the end of the tail plate 5 serves as a wife form for preventing concrete from flowing out to the entire back surface of the skin plate 1 during concrete placement, which will be described later. The airbag 3 installed on the side serves to prevent the earth and sand or muddy water from moving backward in the chamber.

<C> Support Board A support board 4 is installed at the bottom of the skin plate 2.
The support board 4 has a structure capable of protruding outward (downward) from the skin plate 2 by, for example, extending a hydraulic cylinder or the like. The support board 4 is grounded on the excavation section, and balances and supports the shield machine 1 together with the air bag 3 described above.

<4> Concrete Casting Pipe Concrete filling on the back of the segment can be performed through a grout hole provided in the segment. In the present invention, concrete casting pipe 6 is placed along the end of tail plate 5. They are placed and cast concrete filling. The illustrated concrete casting pipe 6 has a case where the end of the tail plate 5 is bent in a U-shape to penetrate the tail plate 5. The concrete casting pipe 6 penetrates the tail plate 5 and extends along the rear surface thereof. 6 may be arranged.

<E> Cutter Head FIG. 2 is a perspective view showing how the cutter head 7 and the rotary drive shaft 71 are attached. A guide 72 is provided on the back surface of the cutter head 7, and the guide 72 is fitted into a guide groove 73 of the rotation drive shaft 71. A movable jack 74 for sliding the cutter head 7 for enlarged excavation is attached to the back of the cutter head 7, and the movable jack 74 has a structure capable of sliding in a bearing hole 75 provided in the rotary drive shaft 71. At the time of enlarged excavation, extended excavation can be performed by extending the movable jack 74 and protruding from the normal cutter head 7 surface.

Hereinafter, the operation of the tunnel section varying device will be described. <A> Enlarged Excavation FIG. 1 is a longitudinal sectional view showing a state in which an excavated section is enlarged and excavated. When the shield machine 1 reaches the section for enlarging the excavation section, the movable jack 74 of the cutter head 7 is extended to excavate the excavation section.

<B> Support plate Simultaneously with the enlarging excavation, the support plate 4 installed on the bottom surface of the skin plate 2 is projected outward (downward) from the skin plate 2 by elongating a hydraulic cylinder, for example, so that the excavation section is formed. Grounding and balancing and supporting the shield machine 1. At this point, the airbag 3 is still in a folded state.

<C> Air Bag FIG. 3 is a longitudinal sectional view showing a state in which the shield machine 1 has passed through an excavated section enlarged section. Simultaneously with the passage, the movable jack 74 is reduced to return the protruding cutter head portion to a normal state. Also, compressed air or the like is sent into the folded airbag 3 to inflate the airbag 3. By the inflation of the airbags 3 provided at two places before and after the shield machine 1 and the support of the support plate 4, the shield machine 1 is held in a stable state and well-balanced in the enlarged excavation section.

<D> Filled concrete Filled concrete 8 is cast from a concrete casting pipe 6 piped along the tail plate 5. The poured concrete 8 is filled in the back surface of the segment 9 and in the space of the ground, and the airbag 3 arranged near the tail plate 5 prevents the inside of the shield excavator 1 from turning around. The filling work of the filling concrete 8 is sequentially performed according to the progress of the shield machine 1.

<E> Removal of Segment FIG. 4 is a longitudinal sectional view showing a state where the filling operation of the filling concrete 8 is completed. After the hardened concrete 8 is hardened, the segment 9 is removed, and the surface of the hardened concrete in the excavated cross-section enlarged section is cut off to construct a predetermined tunnel cross section.

[0016]

Embodiment 2 FIG. 5 is a partially enlarged longitudinal sectional view showing a second embodiment. In the present embodiment, the folded airbag 32 is arranged on the back surface of the tail plate 5 and the folded airbag 31 is arranged also on the back surface of the segment 9 in the enlarged section of the excavated cross section. The concrete casting pipe 6 is arranged along the rear surface of the tail plate 5 so as to penetrate the tail plate 5. Air bag 31,
After injecting compressed air or the like into the airbag 32 and inflating it, the filled concrete 8 is cast on the back of the airbags 31 and 32.
After the filled concrete 8 has hardened, the segments 9 and the airbag 31 are removed to construct a predetermined enlarged cross section.

[0017]

Third Embodiment FIGS. 6 to 8 are plan views (or longitudinal sectional views) showing a case where soft ground is excavated. A ground improvement zone G is formed before and after the excavated cross-section enlarged section. When the shield machine 1 reaches the excavation section enlarged section, the cutter head 7 is slid as described above to start enlarged excavation. (FIG. 6) Along with the excavation of the shield excavator 1, the segments 9 are assembled by a normal method, and the air bag 3 arranged on the back of the tail plate 5 at the end of the shield excavator 1 is inflated by sending compressed air or the like into the air bag 3. Concrete 8 is cast. (FIG. 7) The holding of the shield machine 1 by the enlarged excavation is the same as that described above, and the illustration and description are omitted. After the hardened concrete 8 is hardened, the segment 9 in the excavated cross-section enlarged section is removed, and the shaved concrete 8 is completed so as to have a predetermined enlarged cross section. (FIG. 8)

[0018]

Since the present invention has been described above,
The following effects can be obtained. <B> Since an enlarged cross section can be constructed during the excavation, there is no need for shaft work to provide a connection part for cables and pipes, a junction, a branch point, a shelter, and the like, and the construction period and construction cost can be reduced. <B> The construction cost of backfill injection is reduced because only backfill concrete is used instead of normal backfill injection. <C> In the section where the excavated cross section is enlarged, the shield excavator is held in a well-balanced manner by the support plate and the airbag, so that stability is good.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a basic configuration of a tunnel section variable device according to the present invention.

FIG. 2 is a perspective view showing a state of attachment between a cutter head and a rotary drive shaft.

FIG. 3 is a vertical cross-sectional view showing a state in which the shield machine has passed an excavated cross-section enlarged section.

FIG. 4 is a longitudinal sectional view showing a state where a filling operation of filling concrete is completed.

FIG. 5 is a partially enlarged longitudinal sectional view showing a second embodiment.

FIG. 6 is a plan view (or a vertical cross-sectional view) illustrating a case where soft ground is excavated.

FIG. 7 is a plan view (or a vertical cross-sectional view) showing the state in which the filling concrete is cast.

FIG. 8 is a plan view (or a vertical cross-sectional view) showing the state in which a predetermined enlarged cross section is obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Nakamura 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation

Claims (5)

[Claims] An excavating section varying device for excavating a shield tunnel and changing an excavating section during the excavation, wherein an airbag is arranged on a back surface of a skin plate of the shield excavator. , A support plate protruding outward from the skin plate is installed, concrete casting pipes are arranged along the end of the tail plate of the shield machine, and the cutter head is slidable. Variable device. 2. The tunnel section varying device according to claim 1, wherein airbags are arranged on the back of the skin plate and the back of the segment of the shield machine. 3. A tunnel section changing method for excavating a shield tunnel and changing an excavation section during the excavation, wherein the shield excavator excavates by enlarging a cutter head when reaching an excavation section enlarging section. In addition to extending the support plate below the enlarged excavation space, inflating the airbag on the back of the skin plate, filling concrete sequentially from the back of the enlarged excavation section on the back of the segment in the direction of excavation. A method for varying a tunnel section, comprising removing and shaving a surface of a filled concrete to construct a predetermined tunnel section. 4. The tunnel section changing method according to claim 3, wherein a segment having an airbag disposed on the back of the segment is assembled in the enlarged excavation space, and the airbag on the back of the segment and the airbag on the back of the skin plate are inflated simultaneously. From the rear of the enlarged excavation space, in the direction of excavation, fill concrete so as to surround the air bag on the back of the segment.After the filled concrete has hardened, remove the segment of the enlarged excavation part and construct a predetermined tunnel cross section. A method for varying the cross section of a tunnel. 5. The tunnel section changing method according to claim 3, wherein the shield excavator improves the ground of the excavated section enlarged section before reaching the excavated section enlarged section, and the shield excavator has the excavated section. When the expanded section is reached, the cutter head is expanded and excavated to assemble the segment of the enlarged excavation section, concrete is sequentially filled from the back of the segment to the excavation direction from the back of the enlarged excavation section, and the filled concrete is hardened. A method of changing a tunnel section, comprising removing a segment of an enlarged excavation section, shaving a surface of filled concrete, and constructing a predetermined tunnel section.