Segment

Abstract

To enhance the load resistance of a segment.SOLUTION: A segment 1 comprises: a circular arc-shaped steel frame 2 which is formed into a box shape being open toward an inner peripheral side; and concrete 3 disposed on an inner side of the steel frame 2. The steel frame 2 comprises: a skin plate 4 arranged on an outer peripheral side, and extending in a peripheral direction; a pair of main girders 5 arranged on both sides of the skin plate 4 in a width direction; a pair of joint plates arranged on both sides of the skin plate 4 in the peripheral direction; ribs 7 extending in a width direction, and connecting a pair of the main girders 5; inner peripheral side main reinforcements 11A each arranged on an inner peripheral side of the rib 7, and extending in the peripheral direction; outer peripheral side main reinforcements 11B each arranged on an outer peripheral side of the rib 7, and extending in the peripheral direction; and main reinforcement constriction plates 20 each fixed to the rib 7, and each constricting the inner peripheral side main reinforcement 11A and the outer peripheral side main reinforcement 11B.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a segment. [Background technology]

[0002] The most common tunneling method is the shield method, in which a shield machine is used to excavate the ground while arc-shaped segments are sequentially installed circumferentially and axially behind it to construct a cylindrical tunnel wall (tubular wall).

[0003] Segments are broadly divided into concrete and steel, with the former concrete segments being strong in compression and the latter steel segments being strong in tension. A segment that combines the advantages of both concrete and steel segments (composite segment) is disclosed in, for example, Patent Document 1 listed below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3343090 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, a composite segment is composed of a steel frame covering five sides except the inner circumference, and concrete filled inside the steel frame. This segment has a high load-bearing capacity due to its composite structure made of concrete that is strong against compression and steel that is strong against tension. However, in recent years, there has been a demand for even higher load-bearing capacity for the segments.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to improve the load-bearing performance of segments. [Means for solving the problem]

[0007] A segment according to one aspect of the present invention comprises an arc-shaped steel frame formed into a box shape with an open inner periphery, and concrete poured inside the steel frame, wherein the steel frame comprises a skin plate provided on the outer periphery side and extending in the circumferential direction, a pair of main girders provided on both widthwise sides of the skin plate, a pair of joint plates provided on both circumferential sides of the skin plate, a rib extending in the width direction and connecting the pair of main girders, inner periphery side main reinforcements provided on the inner periphery side of the rib and extending in the circumferential direction, outer periphery side main reinforcements provided on the outer periphery side of the rib and extending in the circumferential direction, and a main reinforcement restraint plate fixed to the rib and restraining the inner periphery side main reinforcements and the outer periphery side main reinforcements.

[0008] In the above-mentioned segment, the main reinforcement restraint plate may be further fixed to the skin plate.

[0009] In the above-mentioned segment, the inner circumferential side main reinforcements and the outer circumferential side main reinforcements may be provided in a plurality at intervals in the width direction, and the main reinforcement restraint plates may be provided in a plurality so as to restrain the inner circumferential side main reinforcements and the outer circumferential side main reinforcements at least every other plate in the width direction.

[0010] The above-mentioned segment may further comprise a second rib provided at a different circumferential position from the rib to which the main reinforcement restraint plate is fixed, and a second main reinforcement restraint plate fixed to the second rib and restraining at least one of the inner circumferential side main reinforcement and the outer circumferential side main reinforcement that are not restrained by the main reinforcement restraint plate. Effect of the Invention

[0011] According to the present invention, the load-bearing performance of the segment can be improved. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view of a tunnel constructed with segments according to an embodiment of the present invention; [Diagram 2] 1 is a plan view of a segment 1 according to an embodiment of the present invention, viewed from the inner periphery side. [Diagram 3] FIG. 3 is a view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a view taken along line IV-IV in FIG. [Diagram 5] FIG. 3 is a view taken along the line VV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] FIG. 1 is a perspective view showing a tunnel 100 constructed with segments 1 according to an embodiment of the present invention. As shown in FIG. 1, the segment 1 is arc-shaped and forms part of a tunnel 100 to be constructed in a borehole, and is connected circumferentially and axially in the borehole to form a cylindrical wall 101 that constructs the tunnel 100 in the borehole.

[0015] A surface lining body 102 is constructed on the inner peripheral side of the cylindrical wall body 101. In addition, a backfilling material 103 is arranged on the outer peripheral side of the cylindrical wall body 101 to fill the gap between the cylindrical wall body 101 and the excavated hole.

[0016] In the following, when a tunnel 100 is constructed using segments 1, the circumferential direction of the tunnel 100 is referred to as the circumferential direction of the segment 1, the axial direction of the tunnel 100 is referred to as the width direction of the segment 1, and the radial direction of the tunnel 100 is referred to as the thickness direction of the segment 1.

[0017] Fig. 2 is a plan view of a segment 1 according to an embodiment of the present invention as viewed from the inner periphery side. In Fig. 2, a part of the concrete 3 of the segment 1 is removed to improve visibility. Fig. 3 is a view taken along the line III-III shown in Fig. 2. As shown in FIG. 2, the segment 1 is a composite segment including a steel frame 2 covering five sides excluding the inner peripheral surface, and concrete 3 filled inside the steel frame 2.

[0018] The segment 1 comprises an arc-shaped steel frame 2 formed into a box shape with an open inner periphery, and concrete 3 poured inside the steel frame 2.

[0019] The steel frame 2 has a skin plate 4 provided on the outer periphery, a pair of main girders 5 arranged on the sides of the skin plate 4, and a pair of joint plates 6 arranged at the ends of the skin plate 4, and a plurality of ribs 7 are provided between the pair of main girders 5.

[0020] The skin plate 4 is a member that comes into contact with the wall surface of the excavated hole when the tunnel is constructed, and has a curved plate shape that is curved along the circumferential direction. A pair of main girders 5 are arranged parallel to each other and extend from both ends of the skin plate 4 in the width direction toward the inside (inner circumferential side) in the thickness direction, and have a curved shape along the circumferential direction, similar to the skin plate 4.

[0021] The pair of joint plates 6 are rectangular plates extending from both circumferential ends of the skin plate 4 toward the inside in the thickness direction (inner circumferential side), and are disposed between the pair of main girders 5 described above. The skin plate 4, the pair of main girders 5, and the pair of joint plates 6 are connected by welding.

[0022] Further, the pair of main girders 5 are formed with insertion holes 5a for connecting the segments 1 in the width direction. Of the pair of main girders 5, a joint member 5b for connecting to the other segment 1 is disposed in the insertion hole 5a formed in the main girder 5 on one side.

[0023] Furthermore, the pair of joint plates 6 are formed with a plurality of insertion holes 6a through which joint members (not shown) that connect the segments 1 to each other in the circumferential direction are inserted. The concrete 3 has recesses 3a formed at positions corresponding to the insertion holes 5a and 6a, in which joint members (not shown) for connecting to other segments 1 are disposed.

[0024] The rib 7 is generally plate-shaped and extends in the width direction, with both ends fixed to the pair of main girders 5 by welding or the like, and is disposed with the plate surface facing the circumferential direction. The rib 7 is disposed between the pair of main girders 5 so that a gap is formed between the rib 7 and the skin plate 4.

[0025] The ribs 7 include existing ribs 7 and added ribs (first rib 7A and second rib 7B). The existing ribs 7 are provided in pairs at three locations: the circumferential center, one end, and the other end. Between the ribs 7 located at the circumferential center, the insertion holes 5a of the pair of main girders 5 described above and the injection hole 9 are provided. The injection hole 9 penetrates the center of the skin plate 4 and is a hole for injecting backfilling material 103 (see FIG. 1) to the outer periphery.

[0026] Between the ribs 7 located at one end in the circumferential direction, the pair of insertion holes 5a for the main girders 5 described above are disposed. Of the ribs 7, the rib 7 located at one end in the circumferential direction (the joint plate 6 side) is provided with a pair of first reinforcing ribs 8 spaced apart in the width direction. The first reinforcing rib 8 extends in the circumferential direction and connects between the joint plate 6 and the rib 7. The rib 7 and the first reinforcing rib 8 are also connected by a second reinforcing rib 10 extending in a direction intersecting the circumferential direction.

[0027] Furthermore, the insertion holes 5a of the pair of main girders 5 described above are disposed between the ribs 7 located at the other circumferential end. Of the ribs 7, the rib 7 located on the other circumferential end side (joint plate 6 side) is provided with a pair of first reinforcing ribs 8 spaced apart in the width direction. The first reinforcing rib 8 extends in the circumferential direction and connects between the joint plate 6 and the rib 7. The rib 7 and the first reinforcing rib 8 are also connected by a second reinforcing rib 10 extending in a direction intersecting the circumferential direction.

[0028] The added ribs (first rib 7A and second rib 7B) are provided in the gap between the rib 7 arranged at the circumferential center and the rib 7 arranged at one circumferential end, and in the gap between the rib 7 arranged at the circumferential center and the rib 7 arranged at the other circumferential end. The added ribs (first rib 7A and second rib 7B) are provided with a main reinforcement restraint plate 20, which will be described later. Note that this main reinforcement restraint plate 20 may be provided on the existing rib 7.

[0029] A plurality of main reinforcements 11 and a plurality of distribution reinforcements 12 are arranged inside the steel frame 2. The main reinforcements 11 and distribution reinforcements 12 are embedded in the concrete 3 together with the ribs 7 and the like. The main reinforcements 11 are reinforcing bars extending in the circumferential direction. The distribution reinforcements 12 are reinforcing bars arranged to intersect with the main reinforcements 11.

[0030] The main reinforcements 11 are arranged at intervals in the width direction. As shown in Fig. 3, the main reinforcements 11 are provided on both the inner and outer periphery sides of the rib 7. Hereinafter, the main reinforcements 11 provided on the inner periphery side of the rib 7 will be referred to as inner periphery side main reinforcements 11A. Also, the main reinforcements 11 provided on the outer periphery side of the rib 7 will be referred to as outer periphery side main reinforcements 11B.

[0031] As shown in Fig. 2, the reinforcing bars 12 are arranged so as to straddle the multiple inner periphery side main reinforcements 11A in the width direction. The reinforcing bars 12 are bent into a substantially U-shape and include an intersection portion 12a that intersects with the multiple inner periphery side main reinforcements 11A in the width direction, and a pair of locking portions 12b that extend in the circumferential direction from both ends of the intersection portion 12a. The pair of locking portions 12b are inserted into the gap between the rib 7 and the skin plate 4, and are locked to the outer periphery side of the rib 7.

[0032] A plurality of main reinforcement restraint plates 20 are fixed to the first rib 7A by welding or the like. A plurality of main reinforcement restraint plates 20 are also fixed to the second rib 7B, which is provided at a different position in the circumferential direction from the first rib 7A, by welding or the like. Hereinafter, the main reinforcement restraint plate 20 fixed to the first rib 7A will be referred to as the first main reinforcement restraint plate 20A. Also, the main reinforcement restraint plate 20 fixed to the second rib 7B will be referred to as the second main reinforcement restraint plate 20B.

[0033] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. As shown in Fig. 4, the first main reinforcement restraint plate 20A extends from the first rib 7A to both sides in the thickness direction of the segment 1. An inner circumference side through hole 21 that restrains the inner circumference side main reinforcement 11A is formed in the part of the first main reinforcement restraint plate 20A that extends from the first rib 7A to the inner circumference side. Also, an outer circumference side through hole 22 that restrains the outer circumference side main reinforcement 11B is formed in the part of the first main reinforcement restraint plate 20A that extends from the first rib 7A to the outer circumference side.

[0034] The outer peripheral end of the first main reinforcement restraint plate 20A is fixed to the skin plate 4 by welding or the like. A plurality of first main reinforcement restraint plates 20A are provided so as to restrain the inner periphery side main reinforcements 11A and the outer periphery side main reinforcements 11B at least every other one in the width direction. In the example shown in Fig. 4, the first main reinforcement restraint plates 20A are provided in the first, fourth, sixth, and tenth rows of the inner periphery side main reinforcements 11A and the outer periphery side main reinforcements 11B from the left in the width direction.

[0035] 5 is a cross-sectional view taken along line VV of FIG. 2. FIG. As shown in Fig. 5, the second main reinforcement restraint plate 20B, like the first main reinforcement restraint plate 20A, also extends from the second rib 7B to both sides in the thickness direction of the segment 1. An inner circumference side through hole 21 that restrains the inner circumference side main reinforcement 11A is formed in the part of the second main reinforcement restraint plate 20B that extends from the second rib 7B to the inner circumference side. Moreover, an outer circumference side through hole 22 that restrains the outer circumference side main reinforcement 11B is formed in the part of the second main reinforcement restraint plate 20B that extends from the second rib 7B to the outer circumference side.

[0036] The outer peripheral end of the second main reinforcement restraint plate 20B is fixed to the skin plate 4 by welding or the like. A plurality of second main reinforcement restraint plates 20B are provided so as to restrain at least every other inner periphery side main reinforcement 11A and outer periphery side main reinforcement 11B in the width direction. In the example shown in Fig. 5, the second main reinforcement restraint plate 20B is provided in the second, fifth, seventh, and ninth rows of the inner periphery side main reinforcement 11A and the outer periphery side main reinforcement 11B from the left in the width direction. In other words, the second main reinforcement restraint plate 20B restrains at least one inner periphery side main reinforcement 11A and outer periphery side main reinforcement 11B that is not restrained by the first main reinforcement restraint plate 20A.

[0037] As shown in Figs. 4 and 5, the segment 1 having the above-mentioned configuration is provided with the main reinforcement restraint plate 20 fixed to the rib 7 to restrain the inner circumferential side main reinforcement 11A and the outer circumferential side main reinforcement 11B. Therefore, even if a shear force acts on the inner circumferential side main reinforcement 11A, the outer circumferential side main reinforcement 11B is pulled through the main reinforcement restraint plate 20, and part of the shear force acting on the inner circumferential side main reinforcement 11A can be borne by the outer circumferential side main reinforcement 11B. Therefore, the load-bearing performance against abdominal pressure, etc. of the segment 1 is improved. In addition, the existence of the main reinforcement restraint plate 20 makes it easy to arrange the inner circumferential side main reinforcement 11A and the outer circumferential side main reinforcement 11B in the steel frame 2. Furthermore, the dimensional accuracy in the width direction of the steel frame 2 can be secured by adding the first rib 7A and the second rib 7B to which the main reinforcement restraint plate 20 is fixed.

[0038] As described above, the segment 1 of the present embodiment includes a steel frame 2 in the shape of a circular arc formed in a box shape with an opening on the inner periphery side, and concrete 3 poured inside the steel frame 2. The steel frame 2 includes a skin plate 4 provided on the outer periphery side and extending in the circumferential direction, a pair of main girders 5 provided on both sides in the width direction of the skin plate 4, a pair of joint plates 6 provided on both sides in the circumferential direction of the skin plate 4, a rib 7 extending in the width direction and connecting the pair of main girders 5, inner periphery side main reinforcements 11A provided on the inner periphery side of the rib 7 and extending in the circumferential direction, outer periphery side main reinforcements 11B provided on the outer periphery side of the rib 7 and extending in the circumferential direction, and a main reinforcement restraint plate 20 fixed to the rib 7 and restraining the inner periphery side main reinforcements 11A and the outer periphery side main reinforcements 11B. This configuration can improve the load-bearing performance of the segment 1.

[0039] Moreover, in this embodiment, the main reinforcement restraint plate 20 is further fixed to the skin plate 4. According to this configuration, the skin plate 4 can be restrained by the main reinforcement restraint plate 20, and therefore it is possible to prevent the skin plate 4 from protruding outward when pouring the concrete 3 into the steel frame 2. This makes it possible to further improve the load-bearing performance of the segment 1.

[0040] In this embodiment, as shown in Fig. 4 and Fig. 5, the inner periphery side main reinforcements 11A and the outer periphery side main reinforcements 11B are provided at intervals in the width direction, and the main reinforcement restraint plates 20 are provided in plurality so as to restrain at least every other inner periphery side main reinforcements 11A and outer periphery side main reinforcements 11B in the width direction. With this configuration, the gaps between the main reinforcement restraint plates 20 make it easier to ensure the fluidity of the concrete 3 when it is poured. This makes it easier to integrate the steel frame 2 and the concrete 3, and allows for a higher load-bearing performance to be exhibited.

[0041] In this embodiment, the first main reinforcement restraint plate 20A is fixed to a first rib 7A, and the second main reinforcement restraint plate 20B is fixed to the second rib 7B and restrains at least one of the inner periphery side main reinforcement 11A and the outer periphery side main reinforcement 11B that are not restrained by the first main reinforcement restraint plate 20A. With this configuration, the inner periphery side main reinforcement 11A and the outer periphery side main reinforcement 11B that are not restrained by the first main reinforcement restraint plate 20A can be restrained by the second main reinforcement restraint plate 20B that is arranged at a different position in the circumferential direction. Therefore, the inner periphery side main reinforcement 11A and the outer periphery side main reinforcement 11B of each row can be restrained almost without leakage while securing a gap between the main reinforcement restraint plate 20 and the main reinforcement restraint plate 20. Therefore, a higher load-bearing performance can be exhibited.

[0042] Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The shapes and combinations of the components shown in the above embodiment are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention. [Explanation of symbols]

[0043] REFERENCE SIGNS LIST 1...segment, 2...steel frame, 3...concrete, 3a...recess, 4...skin plate, 5...main girder, 5a...insertion hole, 5b...joint member, 6...joint plate, 6a...insertion hole, 7...rib, 7A...first rib, 7B...second rib, 8...first reinforcing rib, 9...injection hole, 10...second reinforcing rib, 11...main reinforcement, 11A...inner periphery side main reinforcement, 11B...outer periphery side main reinforcement, 12...strength distribution reinforcement, 12a...intersection, 12b...retaining portion, 20...main reinforcement restraint plate, 20A...first main reinforcement restraint plate, 20B...second main reinforcement restraint plate, 21...inner periphery side through hole, 22...outer periphery side through hole, 100...tunnel, 101...cylindrical wall body, 102...surface lining body, 103...backfilling material

Claims

1. An arc-shaped steel frame formed into a box shape with an opening on the inner periphery side; and concrete poured inside the steel frame; The steel frame is a skin plate provided on an outer circumferential side and extending in a circumferential direction; A pair of main girders provided on both sides of the skin plate in the width direction; A pair of joint plates provided on both circumferential sides of the skin plate; A rib extending in the width direction and connecting the pair of main beams; An inner circumferential side main reinforcement provided on the inner circumferential side of the rib and extending in the circumferential direction; An outer circumferential side main reinforcement provided on the outer circumferential side of the rib and extending in the circumferential direction; a main reinforcement restraint plate fixed to the rib and restraining the inner circumferential side main reinforcement and the outer circumferential side main reinforcement.

2. The segment of claim 1 , wherein the main reinforcement restraint plate is further fixed to the skin plate.

3. The inner circumferential side main reinforcement and the outer circumferential side main reinforcement are provided at intervals in the width direction, The segment according to claim 1 or 2, characterized in that a plurality of the main reinforcement restraint plates are provided so as to restrain the inner circumferential side main reinforcements and the outer circumferential side main reinforcements at least every other plate in the width direction.

4. A second rib provided at a position different in the circumferential direction from the rib to which the main reinforcement restraint plate is fixed; The segment according to claim 3, further comprising a second main reinforcement restraint plate fixed to the second rib and restraining at least one of the inner circumferential side main reinforcement and the outer circumferential side main reinforcement that are not restrained by the main reinforcement restraint plate.

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