JP3963241B2 - Tunnel excavation method and tunnel liner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a tunnel excavation method in which a tunnel is excavated by a full-section excavator that supports an excavation reaction force with an extended gripper, and a tunnel liner is arranged in an annular shape along the inner circumference of the excavated tunnel, and the excavation method is preferable. It relates to the tunnel liner used.
[0002]
[Prior art]
Conventionally, when a tunnel is excavated by a tunnel boring machine (hereinafter referred to as TBM) which is a full-section excavator, the excavation reaction force is secured by a gripper. The excavation method is as shown in FIGS.
(A) First, the excavator 1 is fixed to the natural ground E by extending the gripper 3 in the left-right direction (FIG. 6).
(B) Then, the cutter head 2 is rotated and propelled by the thrust jack 4 for excavation (FIG. 5).
(C) When one stroke is dug (FIG. 7), the gripper 3 is contracted (FIG. 8), and the gripper holding part G is advanced (FIG. 9).
(D) The gripper 3 is extended again (FIG. 10), and the next stroke excavation starts.
[0003]
In the above method, the gripper 3 is pressed against the ground E and gripped to support or secure the reaction force (excavation reaction force) generated when the excavator 1 excavates and advances, and is propelled by the thrust jack 4. is doing. Here, when the natural ground strength is not sufficient, the excavation reaction force cannot be ensured, and therefore, the excavation reaction force is changed to a system supported by a jack and a tunnel liner.
[0004]
However, in order to change the excavation reaction force to the method of supporting the excavation reaction force with the jack and the tunnel liner, there is a problem that a considerable preparation time is required and the construction speed is delayed. Not only that, but also the natural ground tightening force increases during the preparation time, which may make it difficult to dig.
[0005]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-mentioned problems of the prior art, and in tunnel excavation by TBM, even if the ground state is bad and the conventional gripper cannot sufficiently obtain a reaction force, the excavation reaction force It is an object of the present invention to provide a tunnel excavation method and a tunnel liner used for the tunnel excavation method that can support or ensure excavation reaction force without changing to a system in which the jack is supported by a jack and a tunnel liner.
[0006]
[Means for Solving the Problems]
According to the present invention, a tunnel excavation method in which a tunnel is excavated by an excavator (for example, full-section excavator) that supports an excavation reaction force with an extended gripper, and a tunnel liner is annularly arranged along the inner circumference of the excavated tunnel. The tunnel liner has a plurality of main girders that are curved along the inner periphery of the tunnel and are arranged at intervals in the tunnel axis direction, and excavation reaction force is secured between the main girders to propel the excavator. The tunnel liner is installed in close contact with the tunnel inner wall where the tunnel liner is excavated, and the gripper of the excavator is extended between the main girders of the tunnel liner to extend the gripper on the rear side in the excavation direction. The excavator is propelled by securing the excavation reaction force by the main girder which is in contact with the side surface of the main girder of the tunnel liner through the buffer material and is in contact with the gripper through the buffer material.
[0007]
The tunnel liner of the present invention is a tunnel liner used in the above tunnel excavation method (excavation method of claim 1), and is a plurality of main girders that are curved along the inner circumference of the tunnel and arranged at intervals in the tunnel axis direction. The main girder is filled and reinforced with sufficient filling members to secure a reaction force for excavation and propel the excavator between the main girders, and on the side of the main girder of the tunnel liner facing the gripper of the excavator Is equipped with cushioning material, so that when the gripper extends between the main girders, it will contact the main girder side surface of the tunnel liner via the cushioning material to ensure excavation reaction force and propel the excavator It is configured.
The tunnel liner of the present invention used in such a tunnel excavation method of the present invention includes a plurality of main girders that are curved along the inner periphery of the tunnel and arranged at intervals in the tunnel axis direction. In between, it is reinforced with a reinforcing member sufficient to secure the excavation reaction force and propel the excavator, and a buffer material is interposed on the side of the main girder of the tunnel liner facing the gripper of the excavator Thus, when the gripper extends between the main girders, the excavator is propelled by abutting against the side face of the main girder of the tunnel liner via a cushioning material to ensure excavation reaction force.
[0008]
According to the present invention having the configuration as described above, when the natural ground is good, the reaction force of the excavation can be ensured by pressing the natural ground with the gripper. On the other hand, if the natural ground is bad and the reaction force due to gripper pressing is insufficient, the gripper is stretched between the main beams of the tunnel liner, directly or via a cushioning material (the cushioning material on the rear side in the digging direction) The main girder is in contact with the main girder and supports the excavation reaction force by the main girder.
[0009]
Further, the space between the main girders of the tunnel liner is filled with a filling member (for example, concrete filled between the main girders) or is reinforced by interposing a reinforcing member. Even transmit the reaction force of excavation. Hereinafter, if the reaction force is transmitted to the rear tunnel liner one after another, the necessary reaction force can be secured.
[0010]
In carrying out the present invention, as a step before pressing the main girder directly or through the buffer member with the gripper, when pressing against the ground with the gripper, the tunnel liner is pressed without directly pressing the ground. You may comprise. At this time, a skin plate having an edge joined to the outer peripheral surface of the main girder and interposed between the main girders is provided, and the gripper is configured to obtain a digging reaction force from the natural ground by pressing the skin plate. It is preferable to do.
If comprised in this way, the gripper of an excavator (for example, full-section excavator) will press on a natural ground via the skin plate between the main girder of the part (gripper part) provided in the left-right direction both sides of the said tunnel liner. Thus, the reaction force can be reliably supported from the natural ground over the entire surface of the skin plate. On the other hand, no load is applied to the main girder of the tunnel liner, and there is no problem such as deformation.
Furthermore, if the ground is pressed through the skin plate, a working space shielded by the tunnel liner having the skin plate is created, so that the safety against the collapse of the ground during excavation work is greatly improved. In other words, the safety of TBMs other than the shield type (safety against inconveniences caused by poor grounds, such as collapse of grounds) is greatly improved.
Further, the skin plate is plastically deformed by being pressed toward the natural ground by a gripper of a full-section excavator. If the skin plate and the outer peripheral surface of the main girder are configured to be joined via a joining member that is easily plastically deformed, the skin plate is maintained without returning to its original form even after the gripper is removed. Is done. As a result, an arch effect (shell effect) due to plastic deformation of the skin plate is applied, and the liner yield strength is improved. Further, the skin plate pushed into the natural ground by the pressing of the gripper is in close contact with the natural ground due to plastic deformation to prevent so-called “slipping”. In addition, the skin plate pushed into the ground receives the slippage caused by the collapse of the ground from the excavated tunnel top, and prevents the slip from the tunnel top to prevent it from going under the tunnel. It can be kept to a minimum, and the possibility of rockfall is minimized.
[0011]
Further, when the tunnel liner is built in close contact with the tunnel inner wall excavated, it is preferable to use a so-called “expansion method”. However, a method of injecting a back-up material between the liner and the excavated tunnel inner wall may be used.
[0012]
Here, the reinforcing member may be a metallic reinforcing member such as H steel, or may be filled with concrete or the like.
When a concrete-filled concrete member is used as the reinforcing member, the concrete-filled or placed segment becomes an industrial waste after removal, which increases the processing cost. On the other hand, a segment that employs a metal reinforcing member as a reinforcing member does not become industrial waste after removal. Therefore, the cost regarding the process after removal can be significantly reduced.
In addition, when a metal reinforcing member is employed, there is no need to spray concrete onto the segment, so dust or the like is not generated, and therefore there is no possibility of deteriorating the working environment (mine environment).
Furthermore, when a metal reinforcing member is used, it is not necessary to wait for the curing time (of the concrete) to obtain the jack reaction force compared with the case of placing concrete, so the work period is shortened. I can do it.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described mainly with reference to FIGS.
In FIG. 1, a tunnel liner 10 formed in an annular shape along the inner periphery of an excavated tunnel is provided with gripper portions 11 of, for example, θ ₁ = 85 ° on both sides in the left-right direction, and upper ends thereof are hinged respectively. 14 is connected to each other by a first general part piece 12A of θ ₂ = 90 °, for example, and a second general part piece 12B of θ ₃ = 35 ° is connected to the lower end part via a hinge 14, for example. Each is connected. A third general part piece 12C is connected to one end of one second general part piece 12B via a hinge 14, and the other end of the third general part piece 12C is connected to the other end. An expansion portion 13 is formed between the second general portion piece 12B.
[0014]
FIG. 2 shows a cross section of the tunnel liner 10. Reference numeral 11A denotes a gripper portion of the tunnel liner 10 disposed at a position where the gripper 3 of the excavator is located, and reference numeral 11 denotes a rearward direction of the excavation direction. It is a gripper part of an adjacent tunnel liner.
[0015]
In these gripper portions 11 and 11A, two main girders 20 and 20 formed of channel steel and curved along the inner periphery of the tunnel are spaced apart in the tunnel axis direction and face the opening side of the channel cross section. And are connected by a spacing member (not shown). The gripper 3 is extended between the main girders 20 and 20 on the front gripper portion 11 </ b> A, and the rear side of the gripper 3 is in contact with the rear main girder 20 via a cushioning material 25. The buffer material 25 is suitably a square steel pipe that fits in the groove of the main beam 20, and a liner plate may be interposed between the gripper 3 and the buffer material 25.
[0016]
In addition, a skin plate 21 is interposed between the two main girders 20 and 20 in the gripper portion 11 adjacent to the rear, and the edges thereof are joined to the outer peripheral surfaces of the two main girders 20 and 20. The skin plate 21 is pressed from the inside of the tunnel and is crimped to the natural ground E. Between the two main beams 20, 20, concrete 26 is cast and filled as the “filling member”.
[0017]
The skin plate 21 may be either a flat steel plate or a keystone plate whose cross section is bent into a corrugated shape, and a reinforcing material such as a longitudinal rib may be interposed between the main girders 20 and 20. good.
[0018]
Due to the structure of the tunnel liner 10 as described above, when the natural ground is good, the reaction force of the excavation can be ensured by pressing the gripper 3 against the natural ground via the skin plate 21. When the ground is bad and the reaction force due to the pressing of the gripper 3 is insufficient, the reaction force is transmitted from the gripper 3 extended between the main girders 20 and 20 to the main girder 20 via the cushioning material 25, and Since it is transmitted to the main beam 20 of the tunnel liner 10 adjacent to the rear, and the concrete 26 is filled between the main beams 20, 20 of the tunnel liner 10, the reaction force is transmitted to the rear tunnel liner 10 below. Necessary reaction force can be secured.
[0019]
In another embodiment shown in FIG. 3, the gripper portion 11M has a skin plate 21M interposed between the outer peripheries of the main beams 20, 20, and the main beam 20 and the skin plate 21M are as shown in FIG. Both ends of a plurality of joining members 22 formed by bending the wire are welded and joined. A plurality of reinforcing members 30 are interposed between the main girders 20 and 20.
[0020]
At the time of excavation, when the skin plate 21M part is pressed by the gripper 3, the joint part 22 is deformed, the skin plate 21M is separated from the main girder 20 and presses the natural ground, and the excavation reaction force can be secured. A reaction force is transmitted between the main beams 20 and 20 via the reinforcing member 30.
[0021]
In this embodiment, in the case of a temporary segment, concrete does not become industrial waste after removal in the case of a temporary segment, and the underground environment due to dust or the like during concrete spraying There is no deterioration. Furthermore, there is an advantage that the construction period can be shortened without waiting for the concrete curing period to apply the jack reaction force.
[0022]
As described above, the embodiment of the present invention has been described using the expansion type tunnel liner, but may be applied to tunnel liners other than the expansion type. When the natural ground is good, the gripper 3 presses the tunnel liner 10 (more precisely, the skin plate 21), but it is also possible to directly press the natural ground.
[0023]
【The invention's effect】
The present invention has the following effects.
(1) When the natural ground is good, the reaction force of the excavation can be secured by pressing the gripper against the natural ground via the skin plate.
(2) When the natural ground is bad and the reaction force due to gripper pressing is insufficient, the gripper is extended between the tunnel liner main girders and the reaction force is transmitted to the main girders via the cushioning material, and the tunnel liner adjacent to the rear In the tunnel liner, the reaction force is transmitted to the rear tunnel liner one after another through the filling member (for example, concrete filled between the main girders) or the reinforcing member, and the necessary reaction force is secured. I can do it.
(3) The present invention can also be applied to a TBM having a plurality of grippers by extending and abutting the grippers between the main beams of adjacent tunnel liners.
(4) Since the main girder is contacted via the cushioning material, damage to the structural member can be reduced as much as possible.
[0024]
(5) If a reinforcing member made of metal such as H steel is used as the reinforcing member, it does not become an industrial waste after the segment is removed, so that the cost related to the treatment after the removal can be greatly reduced.
(6) If a metal reinforcing member is adopted, there is no need to spray concrete onto the segment, so dust and the like are not generated and the working environment is not deteriorated.
(7) When a metal reinforcing member is employed, it is not necessary to wait for the concrete curing time when the jack reaction force is obtained, and the working time can be shortened.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of a tunnel liner used in the present invention.
FIG. 2 is a cross-sectional view of the tunnel liner of FIG.
FIG. 3 is a perspective view showing another embodiment of a tunnel liner.
4 is a perspective view showing details of a joint portion between the main beam and the skin plate of FIG. 3;
FIG. 5 is a cross-sectional view of a tunnel showing a state where excavation is started in a conventional tunnel excavation method.
6 is a cross-sectional view perpendicular to the tunnel axis of FIG. 5;
FIG. 7 is a cross-sectional view showing a state in which the gripper is shrunk by one stroke.
8 is a cross-sectional view perpendicular to the tunnel axis in FIG. 7;
FIG. 9 is a cross-sectional view showing a state where the gripper is advanced.
10 is a cross-sectional view perpendicular to the tunnel axis with the gripper extended from FIG. 9. FIG.
[Explanation of symbols]
1 ... TBM (Excavator)
3 ... Gripper 10 ... Tunnel liner 11, 11A ... Gripper part 20 of tunnel liner ... Main girder 21 ... Skin plate 25 ... Buffer material 26 ... Concrete

Claims (3)

 In a tunnel excavation method in which a tunnel is excavated by an excavator that supports an excavation reaction force with an extended gripper, and the tunnel liner is arranged in an annular shape along the inner circumference of the excavated tunnel, the tunnel liner is curved along the inner circumference of the tunnel. A plurality of main girders arranged at intervals in the tunnel axis direction, the main girders being reinforced with a reinforcing member sufficient to ensure excavation reaction force and propel the excavator, The tunnel liner is installed in close contact with the tunnel inner wall, and the gripper of the excavator is extended between the main girder of the tunnel liner and the gripper is attached to the side surface of the main girder of the tunnel liner through the cushioning material on the rear side in the excavation direction. A tunnel excavation method characterized in that the excavator is propelled while ensuring a excavation reaction force by a main girder that abuts and abuts against a gripper via a cushioning material.  The tunnel liner used in the tunnel excavation method according to claim 1, further comprising a plurality of main girders that are curved along the inner periphery of the tunnel and arranged at intervals in the tunnel axis direction, and excavation reaction force is generated between the main girders. Filling members sufficient to secure and propel the excavator are reinforced and the tunnel liner facing the gripper of the excavator is provided with a cushioning material on the side face of the main girder, thereby A tunnel liner characterized in that when the gripper extends between the main girders, the excavator is propelled by abutting against a side surface of the main girder of the tunnel liner via a cushioning material to ensure excavation reaction force.  The tunnel liner used in the tunnel excavation method according to claim 1, further comprising a plurality of main girders that are curved along the inner periphery of the tunnel and arranged at intervals in the tunnel axis direction, and excavation reaction force is generated between the main girders. A reinforcing member sufficient to secure and propel the excavator is interposed and reinforced, and a cushioning material is interposed on the side surface of the main girder of the tunnel liner facing the gripper of the excavator, and A tunnel liner characterized in that when the gripper extends between the main girders, the excavator is propelled by abutting against the main girder side surface of the tunnel liner via a cushioning material to ensure excavation reaction force.

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