JP6767864B2 - How to build the structure inside the tunnel and the structure inside the tunnel - Google Patents

Description

The present invention relates to an in-tunnel structure for supporting a floor surface formed in the tunnel and a method for constructing the in-tunnel structure.

A shield tunnel is constructed by covering the tunnel opening excavated by the shield machine with segments according to the excavation. After the shield tunnel is constructed, a floor surface is formed at the bottom of the tunnel. Patent Document 1 describes a method of constructing the inside of a tunnel in which a mold is installed in the tunnel to construct a side wall and an invert.
Patent Document 2 describes a floor structure in a tunnel by a box culvert in which an invert block serving as a bottom plate is installed at the bottom of the tunnel, and a pair of side plates and a top plate are pin-coupled on the invert block. ..

Japanese Unexamined Patent Publication No. 2006-152746 Japanese Unexamined Patent Publication No. 2009-150165

In the floor structure described in Patent Document 1, since the side wall and the invert are constructed of cast-in-place concrete, the construction period may be extended. Further, in the floor surface structure described in Patent Document 2, since the box culvert is constructed by connecting the divided bottom plate, the pair of side plates, and the top plate, the construction time may be increased and the construction period may be extended. is there.

An object of the present invention is to provide a tunnel internal structure and a method for constructing a tunnel internal structure that can simplify construction.

The in-tunnel structure according to one aspect of the present invention includes a plurality of culverts having a bottom portion and a pair of side wall portions provided on both sides of the bottom portion, which are installed in the tunnel, and two said side wall portions adjacent to each other. Each of the above is formed so that the cross-sectional thickness in the tunnel cross-sectional direction is thinner than the required performance thickness, the plurality of culverts are continuously arranged in the horizontal direction of the tunnel cross-section, and the two side wall portions adjacent to each other are connected to each other. It is formed so that the cross-sectional thickness connected to the tunnel is equal to or larger than the required performance thickness.

With such a configuration, the present invention can reduce the weight of individual culverts, reduce costs, and improve workability.

The structure in the tunnel may further include connecting portions formed by a filler in which the plurality of culverts are arranged at predetermined intervals and fill the space created between the plurality of culverts.

According to such a configuration, the present invention can integrate adjacent culverts by a connecting portion.

The structure in the tunnel may be configured such that the connecting portion connects the two adjacent culverts via a plurality of joints exposed from the facing surfaces of the two side wall portions adjacent to each other.

According to such a configuration, the present invention can integrate two adjacent culverts.

In the structure inside the tunnel, the culvert may be a box culvert.

The present invention can improve workability and transportability by such a configuration.

The structure inside the tunnel may be formed by dividing the box culvert into upper and lower parts.

The present invention can improve workability and transportability by such a configuration.

In the structure inside the tunnel, the culvert may be a U-shaped culvert.

The present invention can improve workability and transportability by such a configuration.

As for the structure inside the tunnel, an RC floor plate may be installed on the upper part of the U-shaped culvert.

The present invention can improve workability and transportability by such a configuration.

In the structure inside the tunnel, the plurality of culverts may be continuously arranged in the cross-sectional direction of the tunnel, and a pair of end structures may be formed on both sides of the plurality of culverts by fluidized soil.

The present invention can improve workability and transportability by such a configuration.

In the structure inside the tunnel, the plurality of culverts may be continuously arranged in the cross-sectional direction of the tunnel, and end blocks may be arranged on both sides of the plurality of culverts.

The present invention can improve workability and transportability by such a configuration.

The method for constructing an in-tunnel structure according to one aspect of the present invention is a method for constructing an in-tunnel structure in which a plurality of culverts having a bottom portion and a pair of side wall portions provided on both sides of the bottom portion are installed in the tunnel. Each of the two side wall portions adjacent to each other is formed so that the horizontal cross-sectional thickness of the tunnel cross section is thinner than the required performance thickness, and the plurality of culverts are continuously arranged in the horizontal direction of the tunnel cross section. , The two side wall portions adjacent to each other are connected to each other, and the connected cross-sectional thickness is formed so as to be equal to or more than the required performance thickness.

With such a configuration, the present invention can reduce the weight of individual culverts, reduce costs, and improve workability and transportability.

According to the tunnel internal structure and the method for constructing the tunnel internal structure according to the present invention, the construction can be simplified.

It is a perspective view which shows the structure in the tunnel which concerns on 1st Embodiment. It is a figure which shows the method of connecting adjacent box culverts. It is a figure which shows another method of connecting adjacent box culverts. It is a flowchart which shows the method of constructing the structure in a tunnel. It is sectional drawing which shows the shield tunnel. It is a perspective view which shows the state which a pair of box culverts are installed in a shield tunnel. It is a perspective view which shows the state in which a pair of box culverts are connected. It is a perspective view which shows the state which the end structure is provided on both sides of a pair of box culverts. It is a perspective view which shows the structure in the tunnel which concerns on 2nd Embodiment. It is a perspective view which shows the structure in the tunnel which concerns on 3rd Embodiment.

Hereinafter, the tunnel structure 1 according to the embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the tunnel structure 1 is a structure constructed in the shield tunnel 10. The in-tunnel structure 1 is composed of a pair of box culverts 20 installed at the bottom of the shield tunnel 10 and a pair of end structures 40 installed on both sides of the pair of box culverts 20.

The box culvert 20 is, for example, a concrete block formed by precasting. Precast means that it is manufactured in advance at the factory. By assembling the concrete members formed by precasting, the construction period can be shortened compared to the construction method in which concrete is cast on site. The box culvert 20 is formed of, for example, a reinforced concrete structure. The box culvert 20 may be integrally formed or may be divided and formed.

The box culvert 20 has a bottom plate 21 installed at the bottom of the shield tunnel 10, a pair of side wall portions 22 and 23 provided on both sides of the bottom plate 21, and a top plate 24 supported by the side wall portions 22 and 23. .. The bottom plate 21 is a square plate-like body. The bottom plate 21 is curved downward to match the shape of the inner wall 11 of the shield tunnel 10. The bottom surface 21a of the bottom plate 21 is formed so as to match the shape of the inner wall 11 of the shield tunnel 10 when installed at the bottom of the shield tunnel 10.

A pair of side wall portions 22 and 23 are provided standing upward from one end 21b and the other end 21c on both sides of the bottom plate 21 in a direction orthogonal to the tunnel axis L. The side wall portions 22 and 23 are square plate-shaped bodies. When the box culvert 20 is a split type, the split portions 22a and 23a may be provided along the horizontal direction on the way toward the upper side of the side wall portions 22 and 23. The cross-sectional thickness t1 of the side wall portion 22 is formed thinner than the cross-sectional thickness t2 of the side wall portion 23. The cross-sectional thickness t2 of the side wall portion 23 is formed so as to satisfy a predetermined thickness required for design strength (hereinafter, referred to as a required performance thickness). On the other hand, the cross-sectional thickness t1 of the side wall portion 22 is formed to be thinner than the required performance thickness.

The detailed configuration of the side wall portion 22 will be described later. The side wall portions 22 and 23 horizontally support the top plate 24. The top plate 24 is a square plate-like body. With such a configuration, the box culvert 20 is formed with an opening P having a trapezoidal cross section along the tunnel axis L direction of the shield tunnel 10. The pair of box culverts 20 are symmetrically arranged along the horizontal direction of the tunnel cross section. A connecting portion 30 for integrating the pair of box culverts 20 is formed between the pair of box culverts 20. The connecting portion 30 connects two side wall portions 22 facing each other. The connecting portion 30 is formed of, for example, concrete or mortar. The detailed configuration of the connecting portion 30 will be described later.

When the pair of box culverts 20 are connected, a pair of openings P are formed. When the tunnel structure 1 is sequentially constructed in the shield tunnel 10 and made continuous, a continuous opening P is formed. The continuous opening P is used, for example, as an evacuation passage in the event of a disaster. In addition to the evacuation passage, the opening P may be used as a common groove for laying, for example, a ventilation port, communication, a power cable, or the like. The cross-sectional area of the opening P is determined according to the application. Therefore, the pair of box culverts 20 do not always have a symmetrical shape.

A pair of end structures 40 are provided at both ends of the pair of box culverts 20. For example, the height of the upper surface 41 of the end structure 40 is formed to be the same as the height of the top plate 24 of the box culvert 20. The end structure 40 is formed, for example, by fluidized soil. When the end structure 40 is formed of fluidized soil, the side wall portion 23 becomes a part of the formwork. When the tunnel structure 1 is sequentially constructed in the shield tunnel 10, the already formed end structure 40 also becomes a formwork, so that the formwork of the end structure 40 is only provided in a part of the tunnel cross-sectional direction. Good. Therefore, in the tunnel internal structure 1, a part of the formwork can be omitted at the time of construction, and the workability is improved.

When the box culvert 20 is displaced in the horizontal direction, the end structure 40 applies a reaction force to the box culvert 20 in the direction opposite to the displacement. At this time, the end structure 40 is elastically deformed to absorb the kinetic energy generated by the displacement of the box culvert 20, and the end structure 40 becomes a damper for the displacement of the box culvert 20. Therefore, the end structure 40 converges the vibration generated in the box culvert 20 earlier than in the case where the end structure 40 is absent.

After installing the pair of end structures 40, for example, a soil layer 50 is laid above the top plate 24 and the end structures 40 to form a road surface. In addition to the soil layer, for example, a floor plate may be placed above the top plate 24 to form a road surface on the floor plate. Further, the end structure 40 may be a block formed of, for example, concrete, in addition to the one formed of fluidized soil. When the end structure 40 is a block, workability is improved.

Next, the details of the connecting portion 30 that connects the two opposing side wall portions 22 will be described.

As shown in FIG. 2, a pair of box culverts 20 are arranged at predetermined intervals. In this state, a gap Q is generated. In the gap Q, the ends R1 of the plurality of main reinforcing bars R arranged inside the top plate 24 are exposed from one end 24a side of the top plate 24 of the pair of box culverts 20. The main reinforcing bars R are arranged inside the top plate 24 so that when the plurality of end portions R1 are arranged so as to face each other, they are arranged alternately. The end portion R1 is formed in a loop shape when the main reinforcing bar R is bent and viewed from the tunnel axis L direction. As a result, the end portion R1 becomes a loop joint.

From the facing surfaces 22b of the pair of side wall portions 22 that oppose each other, for example, innumerable joints such as the gibber reinforcing bar T are exposed. A myriad of rebars T that oppose each other are staggered so as not to interfere with each other.

As shown in FIG. 3, instead of the gibber reinforcing bar T, a steel plate gibber G in which a plurality of holes are provided in the strip-shaped steel plate along the axis of the steel plate may be used. After installing the pair of end structures 40, for example, the gap Q is filled with a filler such as concrete or mortar. When the filler is consolidated, the connecting portion 30 is formed. The pair of box culverts 20 are integrated by the connecting portion 30 via a plurality of joints exposed from the facing surface 22b of the side wall portion 22.

When the connecting portion 30 is formed, the thickness of the partition wall formed by the connecting portion 30 and the pair of side wall portions 22 is the cross-sectional thickness t1 of one side wall portion 22 formed thinner than the required performance thickness and the other. The cross-sectional thickness t1 of the side wall portion 22 and the thickness of the connecting portion 30 are added to form a thickness equal to or greater than the required performance thickness.

Next, a method of constructing the tunnel structure 1 will be described.

FIG. 4 is a flowchart showing a process of constructing the tunnel internal structure 1. As shown in FIG. 5, the segments 12 are assembled to construct the shield tunnel 10. As shown in FIG. 6, a pair of box culverts 20 are installed at the bottom of the shield tunnel 10 at predetermined intervals (S10). The box culvert 20 is carried into the starting shaft of the shield machine from the ground, for example. After that, the box culvert 20 is transported from the entrance of the shield tunnel 10 through the inside to the installation point, and is installed by, for example, a crane.

As shown in FIG. 7, the gap Q formed between the pair of box culverts 20 is filled with a filler to form the connecting portion 30 (S11). When the connecting portion 30 is consolidated, the pair of box culverts 20 are integrated. As shown in FIG. 8, a pair of end structures 40 are installed on both sides of the pair of box culverts 20 (S12). The end structure 40 is formed of, for example, fluidized soil. After that, a road surface (not shown) is formed on the upper surfaces of the pair of box culverts 20 and the pair of end structures 40 (S13).

By repeating the above steps and sequentially constructing the tunnel internal structure 1 along the tunnel axis L of the shield tunnel 10, a road surface is formed in the shield tunnel 10. Since the tunnel internal structure 1 continuously constructed in the shield tunnel 10 is constructed under the soil layer 50, the blocks of the tunnel structure 1 adjacent to each other in the tunnel axis L direction are necessarily joints, bolts and PCs. It may not be connected by a connecting member such as a steel material, but it may be connected.

As described above, according to the tunnel structure 1, a part of each box culvert 20 can be made thinner or lighter to improve the transportability, reduce the cost, and improve the workability. According to the structure 1 inside the tunnel, by forming the connecting portion 30 after installing the pair of box culverts 20, it is possible to secure the strength required for the design even if a part of each box culvert 20 is thinned. Safety can be improved.

[Second Embodiment]
In the first embodiment, the structure 1 in the tunnel was constructed by the box culvert 20. The second embodiment shows a modified example constructed with a U-shaped culvert 20U having a U-shaped cross section. In the following description, the same reference numerals will be used for the same configurations as those in the first embodiment, and the same description will be omitted.

As shown in FIG. 9, the tunnel structure 2 has a pair of U-shaped culverts 20U, a connecting portion 30, and a pair of end structures 40. The U-shaped culvert 20U has a structure in which the top plate 24 of the box culvert 20 is removed. After constructing the tunnel structure 2 with the U-shaped culvert 20U, an RC floor plate E made of reinforced concrete, for example, is placed on the upper part of the pair of U-shaped culverts 20U, the connecting portion 30, and the pair of end structures 40. To do. A road surface is formed on the upper surface of the RC floor plate E. When the U-shaped culvert 20U is used, the loading efficiency is improved by arranging them alternately during transportation.

According to the tunnel structure 2, by using the U-shaped culvert 20U, which is lighter than the box culvert 20, the transportability and loadability can be improved, the cost can be reduced, and the workability can be improved.

[Third Embodiment]
In the first embodiment, the tunnel structure 1 is constructed by a pair of box culverts 20. In the third embodiment, a modification using a triple box culvert is shown.

As shown in FIG. 10, the tunnel structure 3 has a series of box culverts 20A, 20B, 20C. In the tunnel structure 3, three spaces PA, PB, and PC are formed by three box culverts 20A, 20B, and 20C. As shown in the figure, the box culverts 20B and 20C are formed symmetrically, but they do not necessarily have to be formed symmetrically.

According to the tunnel structure 3, a plurality of spaces PA, PB, and PC can be formed by using a plurality of box culverts 20A, 20B, and 20C, and spaces can be formed according to the purpose of use.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof. For example, although the above embodiment is illustrated symmetrically, an asymmetrical structure may be constructed by combining one side of the tunnel internal structures 1 to 3 respectively. Further, the structure inside the tunnel may be constructed by using a plurality of culverts of four or more stations based on the above-mentioned technical idea.

1,2,3 ... Tunnel internal structure, 10 ... Shield tunnel, 11 ... Inner wall, 12 ... Segment, 20, 20A, 20B, 20C ... Box culvert, 20U ... U-shaped culvert, 21 ... Bottom plate, 21a ... Bottom, 21b ... One end, 21c ... the other end, 22 ... side wall, 22a ... split, 22b ... facing surface, 23 ... side wall, 23a ... split, 24 ... top plate, 24a ... one end, 30 ... connecting, 40 ... end Structure, 41 ... Top surface, 50 ... Soil layer, E ... Floor board, G ... Steel plate gibber, L ... Tunnel shaft, P ... Opening, PA ... Space, PB ... Space, PC ... Space, Q ... Gap, R ... Main reinforcing bar , R1 ... end, T ... Jibel rebar

Claims (10)

A plurality of culverts installed in a tunnel having a bottom and a pair of side walls provided on both sides of the bottom.
Each of the two side wall portions adjacent to each other is formed so that the cross-sectional thickness in the tunnel cross-sectional direction is thinner than the required performance thickness, and the plurality of culverts are continuously arranged in the horizontal direction of the tunnel cross-section, and two adjacent to each other. It is formed so that the cross-sectional thickness connected when the two side wall portions are connected to each other is equal to or larger than the required performance thickness.
Structure inside the tunnel. The plurality of culverts are arranged apart from each other at predetermined intervals.
Further comprising a connecting portion formed by a filler that fills the space created between the plurality of culverts.
The structure inside the tunnel according to claim 1. The connecting portion connects two adjacent culverts via a plurality of joints exposed from facing surfaces of the two adjacent side wall portions.
The structure inside the tunnel according to claim 2. The culvert is a box culvert,
The tunnel structure according to any one of claims 1 to 3. The box culvert is formed by being divided into upper and lower parts.
The structure inside the tunnel according to claim 4. The culvert is a U-shaped culvert,
The tunnel structure according to any one of claims 1 to 3. An RC floorboard is installed on top of the U-shaped culvert.
The structure inside the tunnel according to claim 6. The plurality of culverts are continuously arranged in the cross-sectional direction of the tunnel, and a pair of end structures are formed on both sides of the plurality of culverts by fluidized soil.
The tunnel internal structure according to any one of claims 1 to 7. The plurality of culverts are continuously arranged in the cross-sectional direction of the tunnel, and end blocks are arranged on both sides of the plurality of culverts.
The tunnel internal structure according to any one of claims 1 to 7. A method for constructing an in-tunnel structure in which a plurality of culverts having a bottom portion and a pair of side wall portions provided on both sides of the bottom portion are installed in the tunnel.
Each of the two side wall portions adjacent to each other is formed so that the horizontal cross-sectional thickness of the tunnel cross section is thinner than the required performance thickness.
The plurality of culverts are continuously arranged in the horizontal direction of the tunnel cross section,
The two side wall portions adjacent to each other are connected to each other, and the connected cross-sectional thickness is formed so as to be equal to or greater than the required performance thickness.
How to build the structure inside the tunnel.

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