JP6173045B2 - Shield tunnel dismantling method - Google Patents

Description

The present invention relates to a method for dismantling a shield tunnel in construction of an underground structure. More particularly, the present invention relates to a shield tunnel disassembly method having a shield tunnel segment structure that can be easily disassembled.

Road tunnels are being investigated deep underground as one of the major urban transport infrastructure development projects. In such a branch and merge part to the underground structure in the deep underground (hereinafter sometimes referred to as the “ramp part”), a construction technique for the underground structure with a large cross section is required, and the ground to the ground such as consolidation settlement is required. Environmental considerations such as impact and groundwater level reduction are required. Conventionally, as an underground structure with a large cross section in a lamp section or the like, a technique for constructing an outer shell covering body of a large cross section tunnel by integrating a plurality of small cross section tunnels adjacent to each other, or a NATM construction method (New Australian Tunneling) A construction technique for constructing a large section tunnel by a mountain method such as Method) is disclosed.

JP 2006-348718 A

By the way, in the process of constructing an underground structure having a large cross section in such a lamp portion, an outer shell covering body is constructed, and there is a state in which a main line tunnel and a lamp tunnel are located on the inner cross section. In order to make a large-section tunnel to be completed from this state, it is necessary to excavate the inner section of the outer shell lining body and dismantle the main tunnel and ramp tunnel segments.

FIG. 1 is a schematic perspective view of shield tunnels connected by segments, and FIG. 2 is a schematic cross-sectional view along the line AA showing a connecting portion as an example of a known technique between segment rings. is there.

As shown in FIG. 1, the shield tunnel is formed by the shield method, and the first segment 1 and the second segment 2 located on the wellhead side with respect to the first segment 1 are the one-pass joint shown in FIG. 2. It is constructed by connecting with 3. As shown in FIG. 2, the one-pass joint includes a male structure provided on the end face on the wellhead side of the first segment 1 and a female structure provided on an end face on the face side of the second segment 2.

FIG. 2 shows an example of the one-pass joint. The end surface 1a of the first segment 1 and the end surface 2b of the second segment 2 are fixed by the one-pass joint 3, and the first segment 1 and the second segment 2 are connected to form a segment structure. Yes. The one-pass joint 3 fixed in the first segment 1 is covered with a cap nut 4. In the present embodiment, an inter-ring joint is used as the one-pass joint 3, and a portion protruding from the first segment 1 constitutes a pin bolt 5, and a serrated screw is cut on the outer peripheral surface thereof. Yes.
As shown in FIG. 2, the one-pass joint 3 is fixed to the first segment 1 by a metal frame 6, and an anchor bar 7 for distributing the stress transmitted from the one-pass joint 3 to the first segment 1. Is attached to the metal frame 6.

On the other hand, the second segment 2 is provided with a wedge-shaped opening 10 and a urethane case 12 for accommodating the urethane spring 11 so that the one-pass joint 3 is received by the urethane spring 11 accommodated in the urethane case 12. It is configured. In FIG. 2, what is indicated by reference numeral 13 is an anchor line.

When the first segment 1 and the second segment 2 configured as described above are connected, the pin bolt 5 of the one-pass joint 3 provided in the first segment 1 is formed in the second segment 2. It is inserted into the wedge-shaped opening 10 and engaged with the urethane spring 11 housed in the urethane case 12.

Thus, since the one-pass joint 3 is embedded and fixed in the first segment 1, it is impossible to release the connection between the first segment 1 and the second segment 2 from the outside or from the inside. There was a problem that it was possible and a special dismantling machine was required to release it.

In addition, since the one-pass joint 3 is not exposed inside or outside the tunnel, it is impossible to cut the connection between the first segment 1 and the second segment 2 by fusing. The dismantling of the shield tunnel that was assembled and built in the ground itself was not done.

Accordingly, an object of the present invention is to provide a method of disassembling a shield tunnel having a segment structure that can be easily disassembled from the outside or inside of the shield tunnel without requiring a special device. is there.

Another object of the present invention is to provide a segment structure constituting a shield tunnel that can be easily disassembled from the outside or the inside of the shield tunnel without requiring a special device.

The present invention is a shield tunnel dismantling method for dismantling a shield tunnel located in a cross section surrounded by an outer shell covering body provided for constructing a large section tunnel from the outside of the shield tunnel,
The segment of the shield tunnel has segment pieces divided in the tunnel axial direction connected in advance by a joint portion, and the joint portion is excavated inside the outer shell covering body through a skin plate to shield tunnel segments. By separating the segment pieces from each other by disengaging from the outside of the shield tunnel, the segment pieces are separated from each other by releasing the connection between the segment pieces after being exposed to the outer surface and peeling off the skin plate. Features.
In addition, the position of the joint portion is different from the position between the rings connected when the shield tunnel is constructed.

According to the present invention, the shield tunnel can be disassembled from the outside, the segments connected to each other can be separated without using a special device, and the shield tunnel can be easily disassembled.

Further, according to the present invention, since the work is performed outside the shield tunnel, there is no need for spark curing inside the shield tunnel.

According to the present invention, it is possible to provide easy disassembly from the outside or inside of the shield tunnel without using a special device.

Furthermore, according to the present invention, it is possible to provide a segment structure of a shield tunnel that can be easily disassembled from the outside or the inside of the shield tunnel without requiring a special device.

FIG. 1 is a schematic perspective view of shield tunnels connected by a conventional one-pass segment. FIG. 2 is a schematic cross-sectional view taken along the line AA in FIG. 1 and shows a connecting portion between segment rings. FIG. 3 is a schematic perspective view showing a lamp portion of the main shield tunnel and the lamp shield tunnel. FIG. 4 is a schematic cross-sectional view of the lamp portion of the main shield tunnel and the lamp shield tunnel. FIG. 5 is a schematic perspective view of a shield tunnel constructed by a segment structure according to a preferred embodiment of the present invention. FIG. 6 is a schematic perspective view of the segment piece. FIG. 7 is a schematic perspective view in which the segment piece of FIG. 6 is divided. FIG. 8 is a schematic cross-sectional view taken along line BB in FIG. 5 and is a schematic diagram showing a process of disassembling segments connected to each other. (A) The state before dismantling. (B) It is the state which removed 30b. (C) is the state which removed further. FIG. 9 is a schematic perspective view of the dismantling. (A) is the state which removed 30b. (B) 30b and 30a are removed together.

FIG. 3 is a schematic perspective view showing the completion of the lamp part 50 of the main shield tunnel 21 and the lamp shield tunnel 22, and FIG. 4 is a cross-sectional view of the lamp part 50 of the main shield tunnel 21 and the lamp shield tunnel 22. . 3 and 4, the broken line indicates that the segment 30 and the segment 31 exist before the ramp unit 50 is completed.

As shown in FIGS. 3 and 4, the main shield tunnel 21 and the lamp shield tunnel 22 extend in a space defined by the outer shell covering body 20.
As shown in FIG. 3 and FIG. 4, the outer shell covering body 20 is constructed by connecting the hollow elements 25 along the circumferential direction and filling the hollow elements 25 with concrete by a known construction method. Is done.

As shown in FIG. 3, after excavating the inner surface of the outer shell covering body 20, it is covered with a waterproof sheet and covering concrete indicated by reference numeral 27.

The main shield tunnel 21 is a segment structure formed by connecting a large number of segments 30 in a ring shape in the circumferential direction of the tunnel in the direction in which the main shield tunnel 21 extends, and connecting end faces in the tunnel direction. Similarly, the lamp shield tunnel 22 is formed by connecting a large number of segments 31 in a ring shape in the circumferential direction of the tunnel in the direction in which the lamp shield tunnel 21 extends, and connecting end faces in the tunnel direction. It is.

The main shield tunnel 21 may be constructed ahead of the lamp shield tunnel 22 or vice versa.

In the excavation of the planned excavation area 23 of the outer shell lining body 20 shown in FIG. 4, the segment 30 of the main shield tunnel 21 and the segment 31 of the lamp shield tunnel 22 are not shown in FIG. It is removed from the outside and dismantled. At the same time, the earth and sand in the planned excavation area 23 of the outer shell covering body 20 is excavated and removed to construct the ramp unit 50.

FIG. 5 is a schematic perspective view of a shield tunnel constructed by a segment structure showing a main shield tunnel 21 or a lamp shield tunnel 22 according to an embodiment of the present invention. FIG. 6 is a schematic diagram of the segment 30 or segment 31. It is a perspective view. Here, there is no difference in the configuration of the segment 30 and the segment 31, and only the size and weight are different. Therefore, in the following description, the embodiment of the segment 30 of the main shield tunnel will be described.

6 to 7 illustrate a joint box 36 that allows the segment 30 to be divided.

As shown in FIG. 7, when the segment 30 is manufactured, one segment 30 is manufactured by fastening the segment piece 30 a and the segment piece 30 b with a bolt nut 32 in the tunnel axis direction. The same applies to the other segments 30 to be connected to the segment 30.

As shown in FIG. 7, the joint box 36 is embedded in the segment body in the segment 30 so as to be exposed on the outer side surface 39 of the segment 30. Here, the outer side surface 39 of the segment 30 refers to the surface facing the natural ground of the main line shield tunnel 21 constructed by forming the segment 30 in a ring shape. The joint box 36 is fixed to the end side where the segment piece 30 a and the segment piece 30 b are combined, and the exposed portion of the joint box 36 is covered with the skin plate 34.

The skin plate 34 is attached so as to cover the opening of the joint box 36 by welding after the segment piece 30a and the segment piece 30b are fastened by the bolt and nut 32.
Furthermore, a tenon and a convex part are provided in the circumferential direction on the end face where the segment piece 30a and the segment piece 30b are connected and joined together, and a water-stop seal is attached along the tenon, although not shown.

As shown in FIGS. 6 to 7, a known one-pass joint 3 serving as a joint between rings is provided on both end faces of the segment piece 30 and has the structure shown in FIG. As shown in FIG. 6, the position of the pin bolt 35 and the opening 10 of the one-pass joint 3 is located at a substantially central portion in the thickness direction of the inner side surface of the segment 30.

The segment piece 30 configured as described above constitutes the main shield tunnel 21 as shown in FIG.

Next, a procedure for excavating the inside of the outer shell covering body 20 to disassemble the main shield tunnel 21 and the lamp shield tunnel 22 will be described.

Although not shown in FIG. 4, first, the main line for disassembling the segment 30 on the upper half side of the main shield tunnel 21 and the segment 31 on the upper half side of the lamp shield tunnel 22 from the outside of each shield tunnel 21 or 22. The tunnel is cut out from the shield tunnel 21 or the lamp shield tunnel 22 toward the planned excavation area 23 of the outer shell covering body 20.

Subsequently, excavation is performed using the earth retaining support, and a work space in which work can be performed is provided in the planned excavation area 23 outside the main shield tunnel 21 or the lamp shield tunnel 22. Excavation is performed in the direction of tunnel extension so that the outer surface of the segment 30 or the segment 31 of the main shield tunnel 21 and the lamp shield tunnel 22 is exposed from the work space, and this work space is expanded.

FIG. 8 is a schematic diagram illustrating the process of disassembling the segments 30 connected to each other.
First, the skin plate 34 shown in FIG. 8A covering the exposed portion of the joint box 36 is peeled off.
As a result, the bolt and nut 32 fixed to the joint box 36 becomes visible from the outside.

Next, as shown in FIG. 8B, the bolts and nuts 32 thus made visible are cut by a fusing device or the like.
As a result, the connection between the segment piece 30a and the segment piece 30b is released, and the connected segment piece 30a and segment piece 30b can be separated as shown in FIG. 8B.

In this state, as shown in FIG. 9A, the position where the connection is released becomes the connection position 38 between the segment rings, which is different from the position 37 between the rings connected when the main line shield tunnel 21 is constructed. Become a place.

That is, when the segment 30 is manufactured, the connection position 38 where the segment piece 30a and the segment piece 30b are fastened by the bolt and nut 32 is separated. It becomes possible to separate the segments 30 with the joint box 36 as a boundary.

Similarly, as shown in FIG. 8C and FIG. 9B, the other segments are similarly separated at the connection position 38 between the segment piece 30a and the segment piece 30b, and along the shield tunnel direction. Demolition can be performed.

The segment 30 to be separated is separated while being fastened by the one-pass joint 3 used when constructing the main shield tunnel 21, and the main shield tunnel 22 is dismantled.

According to this embodiment, the joint box 36 is fixed to the edge of the end face of the segment piece 30a and the segment piece 30b so as to be exposed on the outer surfaces of the segment piece 30a and the segment piece 30b, and the metal joint box 36 Since the exposed portion is covered with the skin plate 34, the bolts and nuts 32 connecting the segment piece 30a and the segment piece 30b can be visually observed by peeling the skin plate 34. , The bolt and nut 32 can be cut, and the segment piece 30a and the segment piece 30b can be disassembled from the outside at a position 38 where the segment piece 30a is connected when the segment 30 is manufactured.

In addition, according to the present embodiment, the portion exposed to the outside of the joint box 36 is only the outer side surface of the segment 30. Therefore, even if the bolt nut 32 is cut by a fusing device, the spark is not connected to the main shield tunnel. Scattering inside 21 can be effectively prevented, and there is no need for spark curing.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.
For example, in the above-described embodiment, the one-pass joint 3 is used as a joint. However, if a segment is provided with a mechanism that cannot be separated once it is pressed against another segment, It can be used as a joint of the invention.

Further, in each of the above embodiments, the metal joint box 36 is fixed so as to be exposed on the outer surface of the segment 30, that is, the segment pieces 30a and 30b, and is connected to each other from the outside of the shield tunnel. From the outside of the shield tunnel by fixing the metal joint box 36 so as to be exposed on the inner surface of the segment 30, i.e., the segment pieces 30a, 30b. The segments 30 connected to each other can be disassembled.

11 First segment 1a End face 2 of first segment 2nd segment 2a End face 3 of second segment 3 One-pass joint (inter-ring joint)
4 Cap nut 5 Pin bolt 6 Metal frame 7 Anchor bar 10 Second segment opening 11 Urethane spring 12 Urethane case 13 Anchor bar 20 Outer shell covering 21 Main line shield tunnel 22 Lamp shield tunnel 23 Drilling area 25 Hollow element 27 Tarpaulin and lining concrete 30 Main shield tunnel segment 31 Lamp shield tunnel segment 30a, 30b Segment piece 32 Bolt nut 34 Skin plate 35 Pin bolt 36 Joint box 37 Connection position 38 when shield tunnel 21 (22) is constructed Segment 30 ( 31) Connection position during manufacture 39 Segment outer surface 50 Lamp section

Claims (2)

A shield tunnel dismantling method for dismantling a shield tunnel located in a cross section surrounded by an outer shell covering provided to construct a large section tunnel from the outside of the shield tunnel,
Segment of the shield tunnel segment pieces together divided in the tunnel axis direction are connected in advance with the joint portion, the shield tunnel through the skin plate of the joint portion by drilling inside the shell lining body By separating the segment pieces from each other by disengaging from the outside of the shield tunnel, the segment pieces are separated from each other by releasing the connection between the segment pieces after being exposed to the outer surface and peeling off the skin plate. A method for dismantling a shield tunnel.
2. The shield tunnel disassembly method according to claim 1 , wherein a position of the joint portion is different from a position between rings connected when the shield tunnel is constructed .

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