JP2018109281A - Tunnel inner structure, and construction method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel inner structure and a construction method therefor that simplify construction work.SOLUTION: A tunnel inner structure according to one embodiment of the present invention includes a plurality of culverts installed in a tunnel, having a bottom part and a pair of side wall parts provided on both sides of the bottom part. Each of the two adjacent side wall parts is formed to have a cross-sectional thickness in a transverse direction of the tunnel thinner than a required performance thickness, and to have the cross-sectional thickness in the transverse direction of the tunnel thicker than the required performance thickness when the two adjacent side wall parts are coupled to each other.SELECTED DRAWING: Figure 1

Description

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

A shield tunnel is constructed by covering a tunnel opening excavated by a shield machine with a segment according to excavation. After the shield tunnel is constructed, a floor is formed at the bottom of the tunnel. Patent Document 1 describes a method for constructing a tunnel, in which a formwork is installed in the tunnel to construct a side wall and an invert.
Patent Document 2 describes a floor surface structure in a tunnel by a box culvert that is assembled by installing an invert block serving as a bottom plate at the bottom of the tunnel and pin-connecting a pair of side plates and a top plate to each other. .

JP 2006-152746 A JP 2009-150165 A

  Since the floor structure described in Patent Document 1 is constructed with side wall and invert made of concrete cast on the spot, the work period may be extended. In addition, the floor structure described in Patent Document 2 is constructed by combining a divided bottom plate, a pair of side plates, and a top plate to construct a box culvert. is there.

  An object of this invention is to provide the construction method of the structure in a tunnel which can simplify construction, and the structure in a tunnel.

  An in-tunnel structure according to an 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 the two side wall portions adjacent to each other. In each of the above, the cross-sectional thickness in the tunnel cross-sectional direction is formed 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 adjacent side wall portions are connected to each other The cross-sectional thickness connected at this time is formed to be equal to or greater than the required performance thickness.

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

  The in-tunnel structure may further include a connecting portion formed by a filler that fills a space generated between the plurality of culverts, with the plurality of culverts being spaced apart at a predetermined interval.

  According to the present invention, the culverts adjacent to each other can be integrated by the connecting portion.

  The in-tunnel structure may be configured to connect two adjacent culverts via a plurality of joints exposed from opposing surfaces of the two side wall portions adjacent to each other.

  According to the present invention, the two adjacent culverts can be integrated by such a configuration.

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

  This invention can improve workability and transportability by such a structure.

  The in-tunnel structure may be formed by dividing the box culvert vertically.

  This invention can improve workability and transportability by such a structure.

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

  This invention can improve workability and transportability by such a structure.

  In the tunnel structure, an RC floor board may be installed on the U-shaped culvert.

  This invention can improve workability and transportability by such a structure.

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

  This invention can improve workability and transportability by such a structure.

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

  This invention can improve workability and transportability by such a structure.

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

  With this 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 tunnel internal construction method according to the present invention, the construction can be simplified.

It is a perspective view which shows the structure in a tunnel which concerns on 1st Embodiment. It is a figure which shows the method of connecting the adjacent box culvert. It is a figure which shows the other method of connecting adjacent box culverts. It is a flowchart which shows the method of building the structure in a tunnel. It is a section perspective view showing a shield tunnel. It is a perspective view which shows the state which installed a pair of box culvert in the shield tunnel. It is a perspective view which shows the state which connected a pair of box culvert. It is a perspective view which shows the state which provides an edge part structure on both sides of a pair of box culvert. It is a perspective view which shows the structure in a tunnel which concerns on 2nd Embodiment. It is a perspective view which shows the structure in a tunnel which concerns on 3rd Embodiment.

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

[First Embodiment]
As shown in FIG. 1, the in-tunnel structure 1 is a structure constructed in a shield tunnel 10. The in-tunnel structure 1 includes 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 a concrete block formed by precast, for example. Precast refers to being manufactured in advance at a factory. By assembling the concrete members formed by precast, the construction period can be shortened compared to the method of placing concrete 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.

  The box culvert 20 has a bottom plate 21 installed at the bottom of the shield tunnel 10, a pair of side walls 22, 23 provided on both sides of the bottom plate 21, and a top plate 24 supported by the side walls 22, 23. . The bottom plate 21 is a square plate-like body. The bottom plate 21 is curved downward in accordance with the shape of the inner wall 11 of the shield tunnel 10. The bottom surface 21 a 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 on the bottom of the shield tunnel 10.

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

  The detailed configuration of the side wall portion 22 will be described later. The side walls 22 and 23 support the top plate 24 horizontally. The top plate 24 is a rectangular plate-like body. The box culvert 20 has an opening P having a trapezoidal cross section along the tunnel axis L direction of the shield tunnel 10 with such a configuration. The pair of box culverts 20 are arranged symmetrically 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 part 30 connects the two side wall parts 22 facing each other. The connecting portion 30 is made 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 is formed. When the in-tunnel structure 1 is sequentially constructed in the shield tunnel 10 and continued, a continuous opening P is formed. The continuous opening P is used as an evacuation passage at the time of a disaster, for example. The opening P may be used as a common groove for laying a ventilation port, communication, power cable, etc., in addition to the escape passage. The cross-sectional area of the opening P is determined according to the application. For this reason, the pair of box culverts 20 is not necessarily symmetrical.

  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 by fluidized soil, for example. When the end structure 40 is formed of fluidized soil, the side wall portion 23 becomes a part of the mold. When the tunnel inner structure 1 is sequentially built in the shield tunnel 10, the end structure 40 that has already been formed becomes a mold, so the mold of the end structure 40 is only provided in a part of the tunnel cross-sectional direction. Good. Therefore, the tunnel inner structure 1 can omit a part of the formwork at the time of construction, and the workability is improved.

  The end structure 40 gives a reaction force in the direction opposite to the displacement to the box culvert 20 when the box culvert 20 is displaced in the horizontal direction. 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 against 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 not provided.

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

  Next, the detail of the connection part 30 which connects two opposing side wall parts 22 is demonstrated.

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

  For example, innumerable joints such as a dowel rebar T are exposed from the opposing surfaces 22b of the pair of side wall portions 22 facing each other. The innumerable dowel rebars T that oppose each other are arranged alternately so as not to interfere with each other.

  As shown in FIG. 3, a steel plate gibel G in which a plurality of holes are provided in a strip-shaped steel plate along the axis of the steel plate may be used instead of the gibber reinforcing bar T. 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, a connecting portion 30 is formed. The pair of box culverts 20 are integrated through a plurality of joints exposed from the facing surface 22 b of the side wall portion 22 by the connecting portion 30.

  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 equal to the cross-sectional thickness t1 of the one side wall portion 22 formed thinner than the required performance thickness, and the other By adding the cross-sectional thickness t1 of the side wall portion 22 and the thickness of the connecting portion 30 to the required performance thickness.

  Next, the construction method of the tunnel inner structure 1 will be described.

  FIG. 4 is a flowchart showing a process for building the tunnel internal structure 1. As shown in FIG. 5, the segments 12 are assembled to build the shield tunnel 10. As shown in FIG. 6, a pair of box culverts 20 are installed at a predetermined interval at the bottom of the shield tunnel 10 (S10). The box culvert 20 is carried into the start shaft of a shield machine from the ground, for example. Thereafter, 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 a crane, for example.

  As shown in FIG. 7, the gap Q generated 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 fluidized soil, for example. Thereafter, road surfaces (not shown) are formed on the upper surfaces of the pair of box culverts 20 and the pair of end structure 40 (S13).

  The road surface is formed in the shield tunnel 10 by repeatedly constructing the in-tunnel structure 1 along the tunnel axis L of the shield tunnel 10 by repeating the above steps. Since the in-tunnel structure 1 continuously built in the shield tunnel 10 is constructed under the soil layer 50, each block of the tunnel structure 1 adjacent in the tunnel axis L direction is not necessarily connected with a joint, a bolt, and a PC. Although it may not be connected by connecting members, such as steel materials, it may be connected.

  As described above, according to the in-tunnel structure 1, a part of each box culvert 20 can be made thinner or lighter to improve transportability, reduce costs, and improve workability. According to the tunnel internal structure 1, by forming the connecting portion 30 after the pair of box culverts 20 are installed, the strength necessary for design can be ensured even if a part of each box culvert 20 is thinned, Safety can be improved.

[Second Embodiment]
In the first embodiment, the in-tunnel structure 1 is constructed by the box culvert 20. 2nd Embodiment shows the modification built with the U-shaped culvert 20U which has a U-shaped cross section. In the following description, the same reference numerals are used for the same configurations as those in the first embodiment, and the same descriptions are omitted.

  As shown in FIG. 9, the in-tunnel structure 2 includes a pair of U-shaped culverts 20 </ b> U, a connecting portion 30, and a pair of end structure 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 inner structure 2 with the U-shaped culvert 20U, an RC floor plate E made of reinforced concrete, for example, is placed on top of the pair of U-shaped culverts 20U, the connecting portion 30, and the pair of end structure 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 staggering them during transportation.

  According to the tunnel inner structure 2, by using the U-shaped culvert 20U that is lighter than the box culvert 20, it is possible to improve transportability and loadability, reduce costs, and improve workability.

[Third Embodiment]
In the first embodiment, the in-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 in-tunnel structure 3 includes three box culverts 20A, 20B, and 20C. In the in-tunnel structure 3, triple spaces PA, PB, and PC are formed by triple box culverts 20A, 20B, and 20C. As illustrated, the box culverts 20B and 20C are formed symmetrically, but are not necessarily formed symmetrically.

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

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example 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 spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof. For example, although the said embodiment illustrated left-right symmetrically, you may build an asymmetrical structure combining each one side of the tunnel inner structures 1-3. Further, the tunnel internal structure may be constructed using a plurality of culverts of four or more based on the above 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 part, 22a ... Dividing part, 22b ... Opposite surface, 23 ... Side wall part, 23a ... Dividing part, 24 ... Top plate, 24a ... One end, 30 ... Connecting part, 40 ... End part Structure: 41 ... Upper surface, 50 ... Soil layer, E ... Floor plate, G ... Steel plate diver, L ... Tunnel shaft, P ... Opening, PA ... Space, PB ... Space, PC ... Space, Q ... Gap, R ... Main rebar , R1 ... end, T ... Giber rebar

Claims (10)

A plurality of culverts having a bottom portion and a pair of side wall portions provided on both sides of the bottom portion, installed in a tunnel;
Each of the two side wall portions adjacent to each other is formed such that a cross-sectional thickness in the tunnel cross-sectional direction is thinner than a required performance thickness, and the plurality of culverts are continuously arranged in the horizontal direction of the tunnel cross-section, The cross-sectional thickness connected when the two side wall portions are connected to each other is formed to be equal to or greater than the required performance thickness.
Tunnel structure. The plurality of culverts are spaced apart at a predetermined interval,
Further comprising a connecting portion formed by a filler filling a space generated between the plurality of culverts,
The tunnel internal structure according to claim 1. The connecting portion connects the two adjacent culverts through a plurality of joints exposed from opposing surfaces of the two adjacent side wall portions,
The in-tunnel structure according to claim 2. The culvert is a box culvert,
The in-tunnel structure according to any one of claims 1 to 3. The box culvert is divided into upper and lower parts,
The in-tunnel structure according to claim 4. The culvert is a U-shaped culvert,
The in-tunnel structure according to any one of claims 1 to 3. An RC floor board is installed on top of the U-shaped culvert.
The in-tunnel structure according to claim 6. The plurality of culverts are continuously arranged in the tunnel cross-sectional direction, and a pair of end structures are formed by fluidized soil on both sides of the plurality of culverts.
The tunnel internal structure according to any one of claims 1 to 7. The plurality of culverts are arranged continuously in the tunnel cross-sectional direction, 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 a tunnel internal structure in which a plurality of culverts having a bottom part and a pair of side wall parts provided on both sides of the bottom part are installed in the tunnel,
Each of the two side wall portions adjacent to each other is formed such that the horizontal section thickness of the tunnel section is thinner than the required performance thickness.
The plurality of culverts are continuously arranged in the horizontal direction of the tunnel cross section,
Two adjacent side wall portions are connected to each other, and the connected cross-sectional thickness is equal to or greater than the required performance thickness.
How to build the tunnel structure.

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