JP2018109279A - Tunnel internal structure and construction method of tunnel internal structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel internal structure having a flexible structure capable of simplifying the construction, and a construction method.SOLUTION: Disclosed tunnel internal structure includes: a pair of L-shaped blocks each of which has a leg part extending downward and a top plate supported by the leg part; and an invert block which has a pair of grooves for supporting a lower end part of the pair of leg parts. The pair of grooves support lower end parts of the pair of L-shaped blocks rotatably around a tunnel axial direction.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 floor surface structure in a tunnel in which a box culvert that opens in the tunnel cross-sectional direction is installed at the center of the tunnel bottom, and concrete blocks for restraining the box culvert are installed on both sides thereof. . 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. .

Japanese Patent No. 5492342 JP 2009-150165 A

  The floor structure described in Patent Document 1 uses a rigid box culvert, and there is a possibility that followability may be reduced with respect to ground deformation caused by an external force such as seismic motion or secular change. 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 the present invention is to provide a tunnel internal structure and a method for constructing the tunnel internal structure that have a flexible structure and can simplify the construction.

  An in-tunnel structure according to one aspect of the present invention supports a pair of L-shaped blocks each including a leg portion hanging downward and a top plate supported by the leg portion, and a lower end portion of the pair of leg portions. An invert block having a pair of grooves, and the grooves support the lower end portion rotatably about the tunnel axis direction.

  According to the present invention, when the L-shaped block is installed on the invert block, the lower end of the leg is positioned in the groove so that the workability is improved, and the lower end and the groove form a rotation mechanism. It can be a structure.

  The in-tunnel structure may form a hinge structure by the groove and the lower end.

  Moreover, the structure in a tunnel may form a rotation spring structure by the said groove part and the said lower end part.

  In the present invention, the leg portion of the L-shaped block can rotate around the groove portion by such a configuration.

  The in-tunnel structure may be configured to further include a cushioning material filled between the L-shaped blocks adjacent to each other.

  With this configuration, the present invention can prevent the adjacent L-shaped blocks from colliding and damaging the portal block.

A method for building a tunnel internal structure according to an aspect of the present invention includes a pair of L-shaped blocks each including a leg portion hanging downward and a top plate supported by the leg portion;
An invert block having a pair of grooves that support the lower ends of the pair of legs, and a method for constructing a structure in a tunnel comprising:
A first step of installing the invert block in a tunnel;
A second step of placing the pair of L-shaped blocks on the invert block,
In the second step, the L-shaped block is placed so that the lower end portion thereof is rotatably supported by the groove portion about the tunnel axis direction.

  According to the present invention, when the L-shaped block is installed on the invert block, the lower end portion of the leg portion is positioned in the groove portion and the workability is improved.

  According to the present invention, when the L-shaped block is installed on the invert block, the lower end of the leg is positioned in the groove so that the workability is improved, and the lower end and the groove form a rotation mechanism. It can be a structure.

  According to the tunnel internal structure and the tunnel internal structure building method according to the present invention, the construction can be simplified while having a flexible structure.

It is a perspective view which shows the structure in a tunnel which concerns on 1st Embodiment. It is a figure explaining the connection part of a top plate and an edge part structure. It is a figure explaining operation | movement of a hinge structure. It is a figure explaining operation | movement of a hinge structure. It is a figure explaining operation | movement of a hinge structure. It is a figure explaining operation | movement of a rotating spring structure. It is a figure explaining operation | movement of a rotating spring structure. It is a figure explaining operation | movement of a rotating spring structure. It is a flowchart which shows the construction method of the structure in a tunnel. It is a section perspective view showing a shield tunnel. It is a figure which shows the state which installed the invert block in the shield tunnel. It is a figure which shows the state which installs an edge part structure in the both ends of an invert block. It is a figure which shows the state which installed the L-shaped block in the invert block and the edge part structure. It is a figure which shows the structure in a tunnel which concerns on 2nd Embodiment. It is a figure 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 tunnel internal structure 1 includes an invert block 20 installed at the bottom of the shield tunnel 10, a pair of L-shaped blocks 30 placed on the invert block 20, and a pair of L-shaped blocks 30 installed on both sides of the pair of L-shaped blocks 30. And an end structure 40.

  The invert block 20 is a concrete block molded by, for example, precast. 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 invert block 20 is formed of, for example, a reinforced concrete structure. The invert block 20 may be formed integrally or may be divided.

  The bottom surface 21 of the invert block 20 is formed in a chip shape that protrudes downward 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. An inclined surface 22 a is formed on the upper surface 22 of the invert block 20 in accordance with the shape of the inner wall 11 of the shield tunnel 10.

  A pair of grooves 23 are formed on the upper surface 22 of the invert block 20 along the direction of the tunnel axis L of the shield tunnel 10. The pair of groove portions 23 are formed in the approximate center of the upper surface 22. Each of the pair of groove portions 23 is formed, for example, with a cross section recessed in a circular shape. As will be described later, a lower end portion 32a of a leg portion 32 of the L-shaped block 30 is brought into contact with each of the pair of groove portions 23.

  A pair of end structures 40 are placed on both sides of the invert block 20 in the direction orthogonal to the tunnel axis L. 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 31 of the L-shaped block 30 described later. The end structure 40 is a hollow block. A space 42 is formed in the end structure 40 along the tunnel axis L direction. The space 42 is filled with mortar or fluidized soil after installation, for example. After the end structure 40 is installed on the inner wall 11 of the shield tunnel 10, for example, a plurality of anchors (not shown) are driven from the space 42 toward the inner wall 11 to fix the end structure 40 and the shield tunnel 10.

  A groove 44 for placing the other end 31b of the L-shaped block 30 is formed in the corner 43 of the upper surface 41 of the end structure 40. The groove 44 is formed in a rectangular cross section. After the end structure 40 is placed on the inner wall 11, the L-shaped block 30 is placed on the invert block 20 and the end structure 40.

  The L-shaped block 30 is a concrete block molded by, for example, precast. The L-shaped block 30 is formed with a reinforced concrete structure, for example. The pair of L-shaped blocks 30 are continuously arranged so as to be symmetrical with each other along the tunnel cross section in the direction orthogonal to the tunnel axis L. The L-shaped block 30 has a top plate 31 that is a rectangular plate-like body. The width of the top plate 31 in the tunnel cross-sectional direction is set to include, for example, one lane of the roadway.

  Thereby, when the vehicle travels, there is no step between the right wheel and the left wheel, and the height difference is reduced, and the traveling performance of the vehicle can be improved. At one end 31a on both sides along the tunnel axis L of the top plate 31, a rectangular plate-like leg portion 32 is provided so as to hang downward. The other end 31b of the top plate 31 protrudes in the horizontal direction of the tunnel cross section.

  The top plate 31 is supported by the leg portion 32 and the other end 31 b placed on the end structure 40. The top plate 31 and the leg portion 32 are rigidly connected. The lower end portion 32a of the leg portion 32 is formed in a circular shape with a cross section protruding downward. The cross-sectional shape of the lower end portion 32 a is formed to fit the cross-sectional shape of the groove portion 23. When placing the L-shaped block 30 from above the invert block 20, the lower end portion 32 a of the leg portion 32 of the L-shaped block 30 is fitted into the groove portion 23 of the inverted block 20, and the L-shaped block 30 is positioned.

  Since the cross-sectional shape of the cross section of the groove portion 23 matches the non-circular shape of the cross section of the lower end portion 32 a, when the lower end portion 32 a fits into the groove portion 23, the lower end portion 32 a rotates relative to the groove portion 23. It becomes possible. Thereby, the rotation mechanism R <b> 1 is formed by the lower end portion 32 a and the groove portion 23. The rotation mechanism R1 has a hinge structure constituted by the lower end 32a and the groove 23. In the rotation mechanism R1, the groove portion 23 supports the lower end portion 32a so as to be rotatable about the tunnel axis direction.

  As shown in FIG. 2, the other end 31 b of the top plate 31 and the groove 44 of the end structure 40 may be connected by a connecting member such as an anchor V, for example, in addition to a simple placement. . The anchor V is inserted into a hole 44a provided in the groove 44 and a hole 31c provided in the other end 31b. A gap between the anchor V and the hole 31c and the hole 44a is filled with, for example, mortar. For example, a buffer material W1 is sandwiched between the other end 31b and the groove 44 in the vertical direction. Between the other end 31b and the groove 44 in the horizontal direction, for example, a support material W2 is sandwiched. The connecting member prevents the L-shaped block 30 from falling off during an earthquake.

  Thereby, the other end 31 b of the top plate 31 is rotatably supported by the groove portion 44. The top plate 31 can be displaced in the horizontal direction along the tunnel cross section by the connecting member and the rotation mechanism R1. When the top plate 31 is displaced in the horizontal direction, the lower end portion 32a of the leg portion 32 is constrained by the groove 23, and the lower end portion 32a is restricted from being displaced in the horizontal direction along the tunnel cross section.

  In this state, the leg portion 32 is supported rotatably about the groove portion 23 with the tunnel axis L direction as an axis. When the top plate 31 is displaced, the leg portion 32 is elastically deformed so as to bend. And the top plate 31 returns to the original position as the deformation of the leg portion 32 returns. The L-shaped block 30 has a flexible structure due to the rotation mechanism R1. The operation of the rotation mechanism R1 will be described in detail later.

  When the L-shaped block 30 is placed on the invert block 20 and the end structure 40, a continuous opening P along the tunnel axis L is formed. The opening P is used as an evacuation passage at the time of disaster after the road surface is formed. 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 L-shaped blocks 30 is not necessarily symmetrical.

  Therefore, the pair of L-shaped blocks 30 may be formed asymmetrically so that the shapes of the respective openings P are different. The pair of L-shaped blocks 30 are spaced apart from each other at a predetermined interval. Thereby, a gap S is formed between the pair of L-shaped blocks 30. The predetermined interval of the gap S is, for example, several centimeters to several tens of centimeters.

  The gap S is filled with a buffer material Q. The buffer material Q is formed, for example, by being filled with soil or lightweight soil. As the buffer material Q, a material other than soil or lightweight soil may be used. When the L-shaped block 30 is displaced in the tunnel cross-section direction by the buffer material Q, the pair of L-shaped blocks 30 are prevented from colliding with each other and being damaged.

  Further, the end structure 40 that receives the other end 31b of the L-shaped block 30 gives a reaction force in the opposite direction to the displacement to the L-shaped block 30 by the groove 44 when the L-shaped block 30 is displaced in the horizontal direction. At this time, the buffer material W1 and the end structure 40 are elastically deformed to absorb the kinetic energy generated by the displacement of the L-shaped block 30, and the end structure 40 becomes a damper against the displacement of the L-shaped block 30. Accordingly, the end structure 40 converges the vibration generated in the L-shaped block 30.

  After installing the pair of L-shaped blocks 30, for example, a soil layer 50 is laid on the top plate 31 and the end structure 40 of the L-shaped block 30 to form a road surface. In addition to the soil layer, for example, a floor plate may be placed on the top plate 31 to form a road surface thereon.

  Next, the operation of the rotation mechanism R1 will be described.

  As shown in FIG. 3, when the displacement in the direction of arrow A occurs in the L-shaped block 30, the lower end portion 32 a of the leg portion 32 is constrained by the groove portion 23. As a result, the leg 32 is rotated in the direction of arrow B about the groove 23 as a center along the direction along the tunnel axis L. The lower end 32 a rotates while sliding on the wall forming the cross section of the groove 23.

  As described above, since the cross-sectional shape of the cross section of the groove portion 23 is rotatably matched to the cross-sectional shape of the cross section of the lower end portion 32a, the rotation mechanism R2 composed of the lower end portion 32a and the groove portion 23 is It may be regarded as a rotatable hinge structure.

  As shown in FIG. 4, when the L-shaped block 30 is displaced in the directions of the arrows A1 and A2 that are separated from each other, the pair of leg portions 32 has the groove portion 23 as a center and the direction along the tunnel axis L is an axis. Rotation in the directions of arrows B1 and B2 that are separated from each other occurs. Although the cushioning material Q is illustrated so as not to rotate, it can adhere to any wall surface of the pair of legs 32 and rotate with any of the pair of legs 32.

  As shown in FIG. 5, when a displacement in the direction of arrows A1 and A2 approaching each other occurs in the L-shaped block 30, the pair of leg portions 32 do not rotate because they exert a reaction force through the cushioning material Q. . In this case, the buffer material Q prevents the pair of L-shaped blocks 30 from colliding with each other and being damaged.

  Although the rotation mechanism R1 has been described as a hinge structure in the above example, other structures may be used for the rotation mechanism R1. As shown in FIGS. 6 to 8, for example, a rotating spring structure may be used for the rotating mechanism R1. The rotary spring structure includes, for example, a lower end portion 32a of a leg portion 32 that protrudes downward in a step shape and a groove portion 23 that is recessed downward in a step shape (see FIG. 8). Similarly, the lower end portion 32a of the leg portion 32 and the groove portion 23 are formed in a stepped shape.

  The rotating spring structure serves as a guide for positioning the L-shaped block 30 in the same manner as the hinge structure when the L-shaped block 30 is installed. In the rotation mechanism R1 having a rotation spring structure, the end portion 32a and the groove portion 23 may be connected by a connecting member such as a bolt or an anchor. In this case, a support member made of an elastic material may be sandwiched between the end portion 32a and the groove portion 23.

  In the rotary spring structure, the lower end portion 32 a rotates without slipping the groove portion 23 when the leg portion 32 rotates. At this time, the rotation of the lower end 32a is restricted by the groove 23, and elastic deformation occurs on the contact surface of the lower end 32a.

  Moreover, when the leg part 32 rotates when the edge part 32a and the groove part 23 are connected with the connection member, the elastic deformation of a connection member will also arise and the restoring force of a connection member or a support material will arise. Therefore, the rotary spring structure has a rotational resistance than the hinge structure, but also generates a restoring force.

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

  FIG. 9 is a flowchart showing a process of building the tunnel internal structure 1. As shown in FIG. 10, the segments 12 are assembled to build the shield tunnel 10. As shown in FIG. 11, the invert block 20 is installed at the bottom of the shield tunnel 10: the first step (S10). The invert block 20 is carried into the start shaft of the shield machine from the ground, for example. Thereafter, the invert block 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 FIG. 12 shows, a pair of edge part structure 40 is installed in the both sides of the invert block 20 (S11). The end structure 40 is installed with a crane, for example. As shown in FIG. 13, a pair of L-shaped blocks 30 are installed from above the invert block 20 and the end structure 40: a second step (S12). At this time, the lower end portion 32 a of the leg portion 32 of the L-shaped block 30 is fitted into the groove portion 23, and the other end 31 b of the top plate 31 is placed in the groove portion 44. As a result, the L-shaped block 30 is reliably positioned at the design position.

  The L-shaped block 30 is placed on the invert block 20 so that the lower end portion 32a is rotatably supported by the groove portion 23 about the tunnel axis L direction. The carry-in route of the L-shaped block 30 is the same as that of the inverted block 20. The gap S between the pair of L-shaped blocks 30 is filled with a buffer material Q.

  Thereafter, road surfaces (not shown) are formed on the top surfaces of the pair of L-shaped blocks 30 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, by having the rotation mechanism R1, it is possible to obtain a flexible structure that deforms when external force is applied and follows the external force. The tunnel inner structure 1 can improve transportability by reducing the thickness and weight of each block so as to have a flexible structure, and can also reduce the cost. Since the pair of end structure 40 is placed on the inclined portion of the inner wall 11 of the shield tunnel 10, the pair of end structure 40 presses the invert block 20 from both sides to prevent the invert block 20 from being displaced. it can.

  According to the tunnel internal structure 1, the width of the top plate 31 in the tunnel cross-sectional direction is set so as to include one lane of the roadway, and there is no step difference between the right wheel and the left wheel when the vehicle travels. As a result, the running performance of the vehicle can be improved. Moreover, since the tunnel internal structure 1 has the groove part 23, positioning of the L-type block 30 can be made easy and workability can be improved. Furthermore, since the L-shaped block 30 can be easily removed in the tunnel internal structure 1, the L-shaped blocks 30 can be removed and repaired or replaced one by one after completion of the tunnel.

[Second Embodiment]
In the first embodiment, the other end 31 b of the top plate 31 of the L-shaped block 30 of the tunnel internal structure 1 is formed in a cut-off shape of the top plate 31. In the second embodiment, a modification of the other end 31b of the top plate 31 of the L-shaped block 30A is shown. 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. 14, the other end 31b of the top plate 31 of the L-shaped block 30A has a corner portion 35 protruding downward. By having the corner portion 35, when the L-shaped block 30 moves in the horizontal direction, the horizontal load of the L-shaped block 30A is dispersed in the groove portion 44 of the end structure 40A as compared with the first embodiment. be able to.

  According to the tunnel internal structure 2, the other end 31 b of the top plate 31 of the L-shaped block 30 </ b> A has the corner portion 35, so that the horizontal load of the L-shaped block 30 can be dispersed and a more stable state can be achieved. it can.

[Third Embodiment]
In the first embodiment, the end structure 40 of the tunnel inner structure 1 is formed of a hollow block. In 3rd Embodiment, the edge part structure 40B shows the example formed with the simplified block.

  As shown in FIG. 15, the in-tunnel structure 3 has a pair of end structures 40B formed of columnar blocks. The end structure 40B is a simplified columnar block obtained by cutting a part of the end structure 40 of the first embodiment. After the pair of end structures 40B are installed and the pair of L-shaped blocks 30 are placed, both sides of the pair of end structures 40B are filled with, for example, fluidized soil.

  According to the tunnel internal structure 3, the simplified end structure 40 </ b> B makes it easy to carry in and install.

  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.

DESCRIPTION OF SYMBOLS 1 ... Tunnel inner structure, 2 ... Tunnel inner structure, 3 ... Tunnel inner structure, 10 ... Shield tunnel, 11 ... Inner wall, 12 ... Segment, 20 ... Invert block, 21 ... Bottom surface, 22 ... Top surface, 22a ... Inclined surface, 23 ... groove part, 24 ... groove part, 30 ... L-shaped block, 30A ... L-shaped block, 31 ... top plate, 31a ... one end, 31b ... other end, 32 ... leg part, 32a ... lower end part, 35 ... corner part, 40 ... end structure, 40A ... end structure, 40B ... end structure, 41 ... upper surface, 42 ... opening, 43 ... corner, 44 ... groove, 50 ... soil layer, P ... opening, Q ... cushioning material , R1 ... rotating mechanism, S ... gap

Claims (5)

A pair of L-shaped blocks comprising legs hanging downward and a top plate supported by the legs;
An invert block having a pair of grooves that support the lower ends of the pair of legs, and
The groove portion rotatably supports the lower end portion about the tunnel axis direction as an axis.
Tunnel structure. A hinge structure is formed by the groove and the lower end.
The tunnel internal structure according to claim 1. A rotary spring structure is formed by the groove and the lower end.
The tunnel internal structure according to claim 1. A cushioning material filled between the L-shaped blocks adjacent to each other;
The in-tunnel structure according to any one of claims 1 to 3. A pair of L-shaped blocks comprising legs hanging downward and a top plate supported by the legs;
An invert block having a pair of grooves that support the lower ends of the pair of legs, and a method for constructing a structure in a tunnel comprising:
A first step of installing the invert block in a tunnel;
A second step of placing the pair of L-shaped blocks on the invert block,
In the second step, the L-shaped block is placed such that the lower end portion is rotatably supported by the groove portion about the tunnel axis direction.
How to build the tunnel structure.

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