JP2001073674A - Joining method for shield tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining method for shield tunnel capable of eliminating the need of separately performing soil retaining works and end cutting works when joining, eliminating the need of constructing a deep starting shaft requiring many auxiliary construction methods, and thus reducing a construction period and a construction cost. SOLUTION: This joining method for a shield tunnel 20 for joining a preceding shield tunnel 30 to a later shield tunnel 40 at a joined part 35 comprises a first step and a second step. In the first step, the preceding shield tunnel 30 is constructed so that the ground 1 is excavated by a preceding shield machine 31, all or a part of a peripheral wall is formed of plain segments 36 during the excavation so as to provide the connected part 35 reinforced for preventing the tunnel from being collapsed. In the second process, the latter shield tunnel 40 is constructed so that the ground 1 is excavated by a latter shield machine 41, and so as to be connected to the preceding shield tunnel 30 at the connected part 35 through the plain segments 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield tunnel joining method for joining a leading shield tunnel and a trailing shield tunnel at a portion to be joined.

[0002]

2. Description of the Related Art Conventional methods for joining shield tunnels include, for example, the following. (1) First, when the succeeding shield tunnel is joined to the preceding shield tunnel at a right angle, the succeeding shield tunnel that constructs the succeeding shield tunnel on the side of the preceding shield tunnel constructed by the preceding shield machine must be accurately placed. After performing a safe earth retaining work on the gap between the two tunnels, mirror-cutting the preceding shield tunnel whose peripheral wall is assembled with reinforced concrete segments (hereinafter referred to as “RC segments”), It was excavated and joined with a shield machine. (2) As shown in FIG. 5, when the shield machine 21 'excavates the ground 1' to construct a shield tunnel 20 'continuous to a predetermined depth D, the ground improvement work 3' is provided on the bottom.
Large start shaft 1 deeper than the given depth D
A plurality of 0's are constructed, and the shield machine 21 'is started horizontally in the direction of the arrow from each of the start shafts 10' provided with the start protection work 2 'to reach the tunnels as shown in FIG. The connection was made at the intermediate shaft 11 'provided with the work 4', or at the connection point 5 'in the ground where the ground improvement work 3' was provided as shown in FIG.

[0003]

However, the conventional method of joining a shield tunnel has the following inconveniences. (1) The former requires earth retaining work to ensure the stability of the tunnel and the safety of work, and also requires mirror cutting work to remove the rebar contained in the surrounding wall. Was increasing. (2) In the latter case, when the starting shaft becomes deeper,
Large soil pressure requires a large-scale retaining wall, large-scale excavation requires measures to lower the groundwater level and ground improvement work on the bottom, and furthermore, start-up protection work becomes large. That is, more auxiliary construction methods are required compared to a starting shaft with a shallow depth, and the construction period and construction cost for constructing the starting shaft have increased.

Accordingly, the present invention eliminates the need for separate earth retaining work and mirror cutting work at the time of joining, and eliminates the need to construct a deep shaft starting shaft that requires many auxiliary methods. It is an object of the present invention to provide a method for joining shield tunnels, which can reduce the time and cost of construction.

[0005]

SUMMARY OF THE INVENTION The present invention is provided to achieve the above object, and the invention according to claim 1 (see, for example, FIG. 1 or FIG. 4) is described as follows. A method of joining a leading shield tunnel 30 and a trailing shield tunnel 40, in which / (1) excavates the ground 1 with a leading shield machine 31, and in the middle of the excavation, all or a part of a peripheral wall is formed by a straight segment 36. The to-be-joined part 35 assembled and reinforced to prevent collapse
The first step of constructing the preceding shield tunnel 30 so as to provide
And a second step of constructing the trailing shield tunnel 40 so as to penetrate the straight segment 36 and join the leading shield tunnel 30 at the joined portion 35. Characteristic method of joining the shield tunnel 20 ”.

According to the present invention, while being reinforced so as to withstand the soil water pressure acting on the outside of the peripheral wall, it is assembled with a straight line segment which can be cut with a cutter bit of a succeeding shield machine. At the part to be joined, the leading shield tunnel and the trailing shield tunnel are joined, so there is no need to perform separate earth retaining work or mirror cutting work at the time of joining, and as a result, it is possible to shorten the construction period and reduce the construction cost it can.

The invention according to claim 2 (see, for example, FIG. 1 and FIG. 3) is described as follows.
Is an inclined portion 33 constructed obliquely downward from the starting shaft 10 provided on the ground 1, and the joined portion constructed so as to draw a vertical curve continuously upward from the inclined portion 33. 35, and a horizontal portion 34 constructed in the horizontal direction continuously to the joined portion 35, and the trailing shield tunnel 40 is connected to a tunnel axis C2 of the trailing shield tunnel 40. 2. The joining of the shield tunnel 20 according to claim 1, wherein the joining is performed in a horizontal direction from the rear of the joined portion 35 at a position where the horizontal portion 34 is aligned with the tunnel axis C <b> 1. 3. Method ”.

According to the present invention, since the leading shield tunnel is constructed obliquely downward from the starting shaft having a shallow depth, it is not necessary to construct a starting shaft having a deep depth which requires many auxiliary construction methods. As a result, it is possible to shorten the construction period for constructing the starting shaft and reduce the construction cost.

Further, the invention according to claim 3 (see, for example, FIG. 2) states that “the reinforcing work performed on the joined portion 35 is performed by: / (a) when assembling the peripheral wall, A tensioning step of introducing tension in the direction (using a PC steel strand 37); and (b) filling the interior of the peripheral wall with a filler 38 when joining the trailing shield tunnel 40;
3. A method for joining a shield tunnel according to claim 1 or 2, further comprising a filling step of releasing the tension.

According to the present invention, when assembling the peripheral wall of the portion to be joined, or when joining the subsequent shield tunnel at the portion to be joined, appropriate reinforcement is applied to the portion to be joined in accordance with each scene. Can be.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for bonding a shield tunnel according to the present invention will be described below in detail with reference to the drawings. In the drawings, the straight line segments 36 are marked with fine dots (dots). In the drawings and the description, the same elements will be denoted by the same reference symbols, without redundant description.

1. SUMMARY OF THE INVENTION (See FIGS. 1 to 4) In the method for joining a shield tunnel according to the present invention, the entire peripheral wall (see FIG. 2) or a part thereof (see FIG. 4) is assembled by the straight segments 36 to prevent collapse. In the joined portion 35 provided with the reinforcing work to prevent the joint, the leading shield tunnel 30 and the trailing shield tunnel 40 are joined by penetrating the straight line segment 36, thereby facilitating the joining operation. As a result, the construction period can be shortened and the construction cost can be reduced.

As shown in FIG. 2 or 4, the straight segment 36 has a thin shape obtained by dividing a cylinder into a plurality of portions in the axial direction, similarly to the ordinary RC segment 32. It is a concrete segment that does not include reinforcing bars or hardware so that it can be cut by the cutter bit 41a of the machine 41. By assembling the straight segments 36 in the circumferential direction, a thin cylindrical segment ring as a peripheral wall is formed. Note that the shape of the segment ring as the peripheral wall is not limited to a cylindrical shape, and may be a rectangular prismatic shape.

As shown in FIG. 2 or FIG. 4, an appropriate number of sheath tubes 36a used for introducing tension are embedded in the unsegmented segments 36 in advance along the circumferential direction.
The sheath tube 36a is also a non-metal (for example, resin) tube so that cutting by the cutter bit 41a of the succeeding shield machine 41 is possible. Further, for example, some of the straight segments 36 located at the top of the peripheral wall have a sheath tube 36a.
Fixing section 36 for fixing PC stranded wire 37 inserted in
b is provided.

In the following, specific examples of the method for joining shield tunnels according to the present invention are Embodiment 1 in which a succeeding shield tunnel is joined obliquely from the back with respect to a preceding shield tunnel, and a case in which the following shield tunnel is joined from the side. The description will be made separately for the second embodiment in which the bonding is performed at a right angle.

2. Embodiment 1 (see FIGS. 1 to 3) Embodiment 1 is to join a succeeding shield tunnel 40 obliquely from the rear to a preceding shield tunnel 30. (1) A preceding shield tunnel provided with a portion 35 to be joined is provided. A first step of constructing the shield tunnel 30 and (2) a second step of constructing the subsequent shield tunnel 40 to be joined at the joined portion 35 are included.

(1) First Step In the first step, as shown in FIG. 1, the ground 1 is excavated by the preceding shield machine 31, and in the course of the excavation, the joint 35
Is a step of constructing the preceding shield tunnel 30 so as to provide the following. Here, the preceding shield tunnel 30 has an inclined portion 33, a portion to be joined 35, and a horizontal portion 34 in this order from the wellhead side, and includes reinforcement work (tensioning step and filling step) performed on the portion to be joined 35. , And is constructed by the following procedures.

First, as shown in FIG. 1, the starting shaft 10 provided on the ground 1
By digging the ground 1 with the preceding shield machine 31 obliquely downward so as to reach the predetermined depth D, the inclined portion 33 in which the entire peripheral wall is assembled by the ordinary RC segment 32 is It is built over. The presence of the inclined portion 33 allows the preceding shield tunnel 30 to reach the predetermined depth D with an arbitrary inclination angle θ, so that the depth d of the starting shaft 10 may be shallower than the predetermined depth D, There is no need to build a deep shaft starting shaft that requires many auxiliary methods. The inclined section 33 and the starting shaft 10 are spaces in which underground facilities such as approach roads and disaster prevention facilities are provided after the shield tunnel 20 is constructed. In addition, a starting protection mechanic 2 is applied to the ground 1 in a direction in which the leading shield machine 31 starts from the starting shaft 10.

Next, as shown in FIG. 1, a ground curve is drawn by a leading shield machine 31 by drawing a vertical curve that is continuous with the inclined portion 33 and upward to a predetermined depth D as shown in FIG. By excavating, the joined portion 35 in which “all” of the peripheral wall is assembled by the straight line segments 36 is constructed over a predetermined section. Due to the presence of the joined portion 35, the following shield machine 41
Since the following shield tunnel 40 can be joined to the preceding shield tunnel 30 by penetrating the straight segment 36 that can be cut by the cutter bit 41a, a separate mirror cutting operation is not required. The ground 1 around the part 35 to be joined may be subjected to ground improvement work 3 for the purpose of stopping water in a narrow range as necessary. Further, the leading shield machine 31 has a mechanism (such as a center bending mechanism) that can draw a vertical curve.

At the same time, when assembling the peripheral wall of the joined part 35, as shown in FIG. 2A, the reinforcing work of the joined part 35 is performed in the circumferential direction of the peripheral wall when assembling the peripheral wall of the joined part 35. A tensioning step for introducing tension is performed. Specifically, in the shield tail 31a of the preceding shield machine 31, the unsegmented segment 3 is formed by an erector (not shown).
6, a PC steel stranded wire 37 is inserted into a sheath tube 36a previously embedded in the unsegmented segment 36, and tension (compression) is applied to the fixing portion 36b by a jack 37a in the circumferential direction. Force). The reinforced straight segments 36 are then pushed out of the shield tail 31a. Since the tensioning step as the reinforcement works can withstand the external soil water pressure even when the unsegmented segment 36 comes out of the shield tail 31a, the tunnel can be constructed without additional earth retaining work. Stability can be achieved. Note that this reinforcement is not limited to the above-described method as long as it has an action of preventing the peripheral wall from collapsing, and the tension may be introduced by another method.

Construction of Horizontal Part 34 Next, as shown in FIG. 1, the leading shield machine 31 is connected to the part to be joined 35 and extends horizontally at a predetermined depth D.
Excavation of the ground 1 at
Horizontal section 34 assembled by C segment 32
Is constructed over a predetermined section. The horizontal section 34 becomes a main tunnel after the construction of the shield tunnel 20.

Reinforcement of Joint 35 by Filling Step Lastly, when joining the subsequent shield tunnel 40, as a reinforcement of the joint 35, as shown in FIG.
A filling step of filling the inside of the peripheral wall of the portion to be joined 35 with the filler 38 and releasing the tension is performed. Specifically, first,
Inside the peripheral wall (segment ring) in which the unsegmented segments 36 are assembled, when the preceding shield machine 31 reaches the reaching shaft or another shield tunnel, and no material or the like enters or exits from behind, the fixing section 36b Filling material 38 (air mortar or solidified mud) is filled in a region defined by plugs 35d provided at both ends of the portion 35 to be joined and 35d (see FIG. 1) with the working passage 38a secured in the vicinity. To solidify. Next, in the work passage 38a, the jack 3
7a is released to release the tension of the PC steel strand 37, and the PC strand 37 is removed from within the sheath tube 36a. This filler 38 can also be cut by the cutter bit 41a of the succeeding shield machine 41 after solidification. With the filling process as the reinforcement, even when the tension of the unsegmented segments 36 is released, it is possible to withstand the external soil water pressure. Can be planned. In addition, this reinforcement is not limited to the above-mentioned method as long as it has an effect of preventing the collapse of the peripheral wall.
It is not limited to air mortar or mud solidification material.

(2) Second Step In the second step, as shown in FIG. 1, the ground 1 is dug by the trailing shield machine 41, and the leading shield tunnel penetrates the unreinforced segment 36 at the portion 35 to be joined. This is a step of constructing a subsequent shield tunnel 40 so as to join the shield tunnel 30. Here, the trailing shield tunnel 40 is positioned rearward in the horizontal direction at a predetermined depth D from the rear of the joined portion 35 at a position where the tunnel axis C2 and the tunnel axis C1 of the horizontal portion 34 are aligned. By excavating the ground 1 with the row shield machine 41, the following shield tunnel 40 in which the entire peripheral wall is assembled by the ordinary RC segment 32
Is formed, and the straight segment 36 and the filler 38 are cut over a predetermined section of the portion 35 to be joined by the cutter bit 41a of the succeeding shield machine 41, and are joined to the preceding shield tunnel 30. The trailing shield tunnel 40 also becomes the main tunnel after the construction of the shield tunnel 20. In addition, the term “the two tunnel axes C1 and C2 are combined” includes not only a case where the axes are completely coincident with each other, but also a case where the axes are slightly misaligned within a joinable range. For example, when joining a large-diameter trailing shield tunnel to a large-diameter leading shield tunnel, the axes may be slightly offset from each other.

(3) By repeating the first step and the second step as needed, a continuous shield tunnel 20 is constructed at a predetermined depth D as shown in FIG. By constructing the shield tunnel 20 in this manner, the joining operation of the preceding shield tunnel 30 and the following shield tunnel 40 becomes easy, and as a result, the construction period can be shortened and the construction cost can be reduced. The interval between the first step and the second step is arbitrary, and may be almost non-existent, or may extend over a long period of several years or more. Further, the shield tunnel 20 having a horizontal curve can be similarly constructed.

3. Second Embodiment (see FIG. 4) In the second embodiment, the succeeding shield tunnel 40 is joined to the preceding shield tunnel 30 at a right angle from the side. A first step of constructing the preceding horizontal shield tunnel 30A or the preceding vertical shield tunnel 30B provided with 35C, and (2) the succeeding horizontal shield tunnel 40 to be joined at the joined portion 35C.
A second step of constructing A. Note that the same parts as those in the first embodiment will not be described repeatedly.

(1) First Step In the first step, as shown in FIGS. 4 (a) and 4 (b), the ground is excavated with a preceding shield machine, and the joint 3
This is a step of constructing the preceding horizontal shield tunnel 30A or the preceding vertical shield tunnel 30B so as to provide 5C. Here, the point that the preceding horizontal shield tunnel 30A and the preceding vertical shield tunnel 30B do not have an inclined portion, and that the structure of the joined portion 35C is different from the first embodiment,
Other points are the same as the first embodiment.

As shown in FIG. 4 (c), a part of the peripheral wall is assembled by the unsmoothed segments 36, and the other part of the peripheral wall is previously formed of the sheath tube 32.
a is assembled by the buried RC segments 32, and is reinforced to prevent collapse. That is, only the portion penetrated by the trailing shield machine 41 is
It is constituted by a straight line segment 36. In the reinforcement work, when assembling the peripheral wall, similarly to the above-described tensioning step, a PC steel strand 37 is inserted into the sheath pipes 32a and 36a to introduce tension in the peripheral direction of the peripheral wall. When the subsequent horizontal shield tunnel 40A is joined, the supporting wall 35a, the reaction body 35b,
An opening reinforcing material 35c is provided, and a filler 38 is filled and solidified in a region defined by the reaction body 35b, the opening reinforcing material 35c, and the straight line segment 36, similarly to the above-described filling step. The tension is released and the PC steel strand 37 is removed.

(2) Second Step In the second step, as shown in FIGS. 4 (a) and 4 (b), the ground is excavated by the following shield machine 41, and
This is a step of constructing the succeeding horizontal shield tunnel 40A so as to penetrate the straight segment 36 and join with the preceding horizontal shield tunnel 30A or the preceding vertical shield tunnel 30B. Here, as shown in FIG. 4C, the cutter bit 41a of the succeeding shield machine 41 cuts a “part” (a part constituted by the straight segment 36) of the peripheral wall of the joined portion 35C. And subsequent horizontal shield tunnel 40A
Are different from the first embodiment in that they are joined at right angles to the sides of the joined portion 35C, and the other points are the same as in the first embodiment.

Here, FIG. 4 (a) shows the following shield machine 41 penetrating the straight segment 36 which forms a part of the peripheral wall at the to-be-joined portion 35C provided in the middle of the preceding horizontal shield tunnel 30A. And the trailing side shield tunnel 40
A shows how A is joined at right angles. FIG.
(B), in the to-be-joined part 35C provided in the middle of the preceding vertical shield tunnel 30B, the trailing shield machine 41 penetrates the straight line segment 36 that forms a part of the peripheral wall,
This shows how the trailing horizontal shield tunnel 40A is joined at a right angle. In addition, although not shown, the following vertical shield tunnel may be joined at a right angle at a portion to be joined provided in the middle of the preceding horizontal shield tunnel. That is, these are examples in which tunnels are joined in a T-shape. Note that the term “intermediate” in these descriptions includes the “end”, and thus includes the case where tunnels are joined in an L-shape.

According to the second embodiment, even when tunnels are joined at right angles, it is not necessary to perform separate earth retaining work or mirror cutting work at the time of joining, and as a result, the construction period is shortened and the construction cost is reduced. Reduction can be achieved.

[0031]

According to the method for joining shield tunnels according to the present invention constituted as described above, it is not necessary to perform separate earth retaining work and mirror cutting work at the time of joining, and many auxiliary methods are required. It is not necessary to construct a start shaft with a deep depth, and as a result, it is possible to provide a method of joining shield tunnels that can shorten the construction period and reduce the construction cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention, wherein (a) is a plan view and (b) is a side view.

FIGS. 2A and 2B are cross-sectional views illustrating a reinforcing process performed on a portion to be joined according to the first embodiment of the present invention, wherein FIG. 2A is a tensioning step and FIG.

FIG. 3 is a side view illustrating a shield tunnel constructed according to the first embodiment of the present invention.

4A and 4B are diagrams illustrating a second embodiment of the present invention, in which FIG. 4A is a perspective view illustrating a case where a preceding horizontal shield tunnel and a following horizontal shield tunnel are joined at a right angle, and FIG. FIG. 7 is a perspective view showing a case where the following and the following horizontal shield tunnel are joined at a right angle, and FIG.

FIG. 5 is a side view showing a conventional shield tunnel joining method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground 2 Start protection 3 Ground improvement 10 Start shaft 20 Shield tunnel 30 Prior shield tunnel 31 Prior shield machine 31a Shield tail 32 RC segment 32a Sheath pipe 33 Inclined part 34 Horizontal part 35 Joined part 35a Bearing wall 35b Reaction force Body 35c Opening reinforcement 35d Plug 36 Straight segment 36a Sheath tube 36b Fixing part 37 PC steel strand 37a Jack 38 Filler 38a Work passage 40 Trailing shield tunnel 41 Trailing shield machine 41a Cutter bit C1 (for horizontal part) Tunnel shaft center C2 (of the following shield tunnel) Tunnel shaft center

Continuing from the front page (72) Inventor Takeshi Sakae 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Nobuaki Kobayashi 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction (72) Inventor Takeshi Kawamoto 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Kazuhiro Kobayashi 1-12-1 Yurakucho, Chiyoda-ku, Tokyo Ishikawajima Construction Materials Co., Ltd. (72) Inventor Shinichiro Ota 1-12-1 Yurakucho, Chiyoda-ku, Tokyo Ishikawajima Building Materials Industry Co., Ltd. F-term (reference) 2D054 AA02 AA04 AC01 EA09

Claims (3)

[Claims] 1. A method for joining a leading shield tunnel and a trailing shield tunnel at a joint to be joined,
(1) Excavating the ground with a preceding shield machine, and in the middle, the whole or a part of the peripheral wall is assembled by a straight line segment, and the joined portion provided with reinforcement for preventing collapse is provided. The first step of constructing the leading shield tunnel, and (2) excavating the ground with the trailing shield machine,
A second step of constructing the trailing shield tunnel so as to penetrate the straight segment and join the leading shield tunnel at the joined portion. . 2. The preceding shield tunnel is constructed such that an inclined portion is formed obliquely downward from a starting shaft provided on the ground, and a vertical curve is drawn upward continuously from the inclined portion. And the horizontal portion constructed continuously in the horizontal direction to the bonded portion, and the trailing shield tunnel is configured to be parallel to the tunnel axis of the trailing shield tunnel. 2. The method according to claim 1, wherein the shield tunnel is constructed so as to extend in a horizontal direction from the rear of the joined portion at a position where the tunnel axis of the portion is aligned. 3. The reinforcing work to be performed on the joined portion,
(A) a tensioning step of introducing a tension in the circumferential direction of the peripheral wall when assembling the peripheral wall, and (b) filling a filler inside the peripheral wall when joining the trailing shield tunnel, 3. The method according to claim 1, further comprising: a filling step of releasing the tension.