segment

Abstract

To enhance the load resistance of a segment, as well as, to reduce costs required for manufacturing.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 6 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; first reinforcing ribs 8 extending in the peripheral direction and each connecting the rib 7 and the joint plate 6; and second reinforcing ribs 10 for each connecting the first reinforcing rib 8 and the joint plate 6 at a corner part between the first reinforcing rib 8 and the joint plates 6.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] The most common tunnel construction method is the shield method, in which a shield machine is used to excavate the ground while arc-shaped segments are installed in the circumferential and axial directions 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 (composite segment) that combines the advantages of both concrete and steel segments is disclosed, for example, in 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, composite segments are made up of a steel frame covering five sides except the inner periphery, with concrete filled inside the steel frame. These segments have a high load-bearing capacity due to their composite structure made up of concrete that is strong in compression and steel that is strong in tension. However, in recent years, there has been a demand for even higher load-bearing capacity for segments and thinner tunnel walls.

[0006] The composite segment has a pair of joint plates on both circumferential sides, which are connected in the circumferential direction by joint members such as bolts. However, when connecting the joint plates with these joint members, the joint plates can deform, making it difficult to maintain high load-bearing performance. On the other hand, manufacturing a steel frame that is strong enough to prevent joint plate deformation by, for example, increasing the thickness of the joint plates requires cost and labor, which is economically disadvantageous.

[0007] The present invention has been made in consideration of the above problems, and aims to improve the load-bearing performance of segments and reduce manufacturing costs. [Means for solving the problem]

[0008] A segment according to one embodiment 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. The steel frame is provided on the outer periphery and comprises a skin plate extending circumferentially, 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 sides of the skin plate in the circumferential direction, a rib extending in the width direction and connecting the pair of main girders, a first reinforcing rib extending in the circumferential direction and connecting the rib to the joint plate, and a second reinforcing rib connecting the first reinforcing rib to the joint plate at the corner between the first reinforcing rib and the joint plate.

[0009] In the above-mentioned segment, the joint plate may be provided with a joint installation portion where a joint member is installed, the first reinforcing rib may be arranged in the vicinity of the joint installation portion, and the second reinforcing rib may be arranged on the opposite side of the first reinforcing rib from the joint installation portion side.

[0010] In the above-mentioned segment, the joint plate may be provided with a joint installation portion where a joint member is installed, the first reinforcing ribs may be arranged in a pair on either side of the joint installation portion, and the second reinforcing rib may be arranged on the opposite side of each of the pair of first reinforcing ribs from the joint installation portion side.

[0011] In the above-mentioned segment, the second reinforcing ribs arranged near the main girder may be smaller than the second reinforcing ribs arranged away from the main girder.

[0012] In the above segment, the second reinforcing rib may have a right-angled triangular shape when viewed in the thickness direction.

[0013] In the above segment, the second reinforcing rib may have a plate shape extending obliquely with respect to the width direction when viewed in the thickness direction. [Effects of the Invention]

[0014] According to the present invention, it is possible to improve the load-bearing performance of the segments and reduce the manufacturing costs. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a tunnel constructed with segments according to a first embodiment of the present invention. FIG. [Figure 2] 1 is a plan view of a segment according to a first embodiment of the present invention, viewed from the inner peripheral side. [Figure 3] 1 is an enlarged view showing a reinforcing structure of a joint plate according to a first embodiment of the present invention. [Figure 4] FIG. 10 is an enlarged view showing, as a first comparative example, a reinforcing structure of a joint plate in which a second reinforcing rib is not provided. [Figure 5] FIG. 10 is an enlarged view showing a reinforcing structure of a joint plate in a second comparative example in which a second reinforcing rib is provided at a corner between a rib and a first reinforcing rib. [Figure 6] FIG. 4 is an enlarged view showing a reinforcing structure of a joint plate according to a modified example of the first embodiment of the present invention. [Figure 7] FIG. 6 is an enlarged view showing a reinforcing structure of a joint plate according to a second embodiment of the present invention. [Figure 8] FIG. 10 is an enlarged view showing a reinforcing structure of a joint plate according to a modified example of the second embodiment of the present invention. [Figure 9]FIG. 10 is an enlarged view showing a reinforcing structure of a joint plate according to another modified example of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] (First embodiment) FIG. 1 is a perspective view showing a tunnel 100 constructed with segments 1 according to a first embodiment of the present invention. As shown in Figure 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 within the borehole to form a cylindrical wall 101 that constructs the tunnel 100 within the borehole.

[0018] A surface lining 102 is constructed on the inner periphery of the cylindrical wall 101. In addition, a backfill material 103 is arranged on the outer periphery of the cylindrical wall 101 to fill the gap between the cylindrical wall 101 and the excavated hole.

[0019] In the following, when a tunnel 100 is constructed using segment 1, the circumferential direction of the tunnel 100 will be referred to as the circumferential direction of segment 1, the axial direction of the tunnel 100 as the width direction of segment 1, and the radial direction of the tunnel 100 as the thickness direction of segment 1.

[0020] Fig. 2 is a plan view of the segment 1 according to the first embodiment of the present invention as viewed from the inner periphery side. Note that Fig. 2 shows a state in which part of the concrete 3 of the segment 1 has been removed to improve visibility. As shown in FIG. 2, the segment 1 is a composite segment including a steel frame 2 covering five sides except for the inner peripheral surface, and concrete 3 filled inside the steel frame 2.

[0021] The segment 1 includes a circular arc-shaped steel frame 2 formed in a box shape with an opening on the inner periphery side, and concrete 3 poured inside the steel frame 2.

[0022] As shown in Figure 2, 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 multiple ribs 7 are provided between the pair of main girders 5.

[0023] 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 curves in the circumferential direction. The pair of main girders 5 are arranged parallel to each other, extending from both widthwise ends of the skin plate 4 toward the inside (inner circumferential side) in the thickness direction, and have a curved shape along the circumferential direction, just like the skin plate 4.

[0024] 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 arranged between the pair of main girders 5 mentioned above. The skin plate 4, the pair of main girders 5, the pair of joint plates 6, the ribs, and the first reinforcing rib 8 and second reinforcing rib 10 described below are connected by welding.

[0025] In addition, a pair of main girders 5 are formed with a plurality of (three in this embodiment) insertion holes 5a at predetermined intervals in the circumferential direction, through which joint members (not shown) that connect the segments 1 in the width direction are inserted.

[0026] Furthermore, the pair of joint plates 6 are formed with a plurality of insertion holes 6a (joint installation portions) through which joint members (not shown) that connect the segments 1 together 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 the joint members are to be placed.

[0027] The rib 7 is generally plate-shaped and extends in the width direction, with both ends fixed to a pair of main girders 5. The rib 7 is disposed with its 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.

[0028] The ribs 7 are provided in pairs at three locations: the circumferential center, one end (left side in Fig. 2), and the other end (right side in Fig. 2). Between the ribs 7 located at the circumferential center, the insertion holes 5a for the pair of main girders 5 described above and the injection holes 9 are arranged. The injection holes 9 penetrate the center of the skin plate 4 and are used to inject backfill material 103 (see Fig. 1) toward the outer periphery.

[0029] Between the ribs 7 located at one end in the circumferential direction, the insertion holes 5a of the pair of main girders 5 described above are arranged. Of the ribs 7, the rib 7 located at one end in the circumferential direction (left side in Figure 2) is provided with a pair of first reinforcing ribs 8 spaced apart in the width direction. The first reinforcing ribs 8 extend in the circumferential direction and connect the joint plate 6 and the rib 7.

[0030] Furthermore, the insertion holes 5a for the pair of main girders 5 described above are arranged between the ribs 7 located at the other circumferential end. Of the ribs 7, the rib 7 located at the other circumferential end side (left side in FIG. 2) is provided with a pair of first reinforcing ribs 8 spaced apart in the width direction. The first reinforcing ribs 8 extend in the circumferential direction and connect the joint plate 6 and the rib 7.

[0031] Fig. 3 is an enlarged view showing the reinforcing structure of the joint plate 6 according to the first embodiment of the present invention. Fig. 3 is an enlarged view of the other circumferential end side (the right side in Fig. 2) of the segment 1 shown in Fig. 2, and shows a state in which the concrete 3 of the segment 1 has been removed to improve visibility. As shown in FIG. 3, the joint plate 6 is reinforced by the first reinforcing rib 8 and the second reinforcing rib 10 described above.

[0032] The second reinforcing rib 10 connects the first reinforcing rib 8 and the joint plate 6 at the corner where the first reinforcing rib 8 and the joint plate 6 intersect at a substantially right angle. As shown in Fig. 3, the second reinforcing rib 10 has a right-angled triangular shape in a plan view seen from the thickness direction.

[0033] 3, the hypotenuse of the right-angled triangle of the second reinforcing rib 10 extends at an angle of 45 degrees to the width direction, but the angle and shape are not limited to this. The second reinforcing rib 10 is disposed with its plate surface facing the thickness direction.

[0034] A plurality of second reinforcing ribs 10 may be provided at intervals in the thickness direction. At least one of the second reinforcing ribs 10 may be located at the same position (same depth) in the thickness direction as the insertion hole 6a provided in the joint plate 6. The second reinforcing rib 10 may also be a right-angled triangular prism extending in the thickness direction.

[0035] The second reinforcing rib 10 is disposed on the inner side in the width direction of the first reinforcing rib 8. An insertion hole 6a of the joint plate 6 is disposed on the outer side in the width direction of the first reinforcing rib 8. As shown in FIG. 2, a recess 3a is formed in the concrete 3 at a position corresponding to the insertion hole 6a, and therefore the second reinforcing rib 10 is disposed on the opposite side of the first reinforcing rib 8 from the recess 3a so as not to interfere with the joint member disposed in the recess 3a.

[0036] Next, the operation of the segment 1 having the above configuration will be described with reference to a comparative example shown in FIGS.

[0037] FIG. 4 is an enlarged view showing, as a first comparative example, the reinforcing structure of the joint plate 6 in the case where the second reinforcing rib 10 is not provided. In the reinforcement structure of the joint plate 6 shown in Figure 4, when a load F is applied by the joint member, the vicinity of the insertion hole 6a of the joint plate 6 is pulled outward in the circumferential direction, causing the joint plate 6 to deform in a wavy manner (see the dashed line indicated by symbol 6A).

[0038] In the comparative example shown in Fig. 4, although the first reinforcing rib 8 is present, the joining range in the width direction to the joint plate 6 is narrow with only the first reinforcing rib 8, and therefore the squareness at the corner between the first reinforcing rib 8 and the joint plate 6 cannot be maintained. As a result, the joint plate 6 is deformed, and the joint structure cannot exhibit its load-bearing performance.

[0039] FIG. 5 is an enlarged view showing the reinforcing structure of joint plate 6 in which second reinforcing ribs 10 are provided at the corners between the rib and first reinforcing rib 8, as a second comparative example. In the reinforcement structure of the joint plate 6 shown in Figure 5, when a load F is applied by the joint member, the vicinity of the insertion hole 6a of the joint plate 6 is pulled outward in the circumferential direction, and the joint plate 6 is deformed in a wavy manner, as in Figure 4 (see symbol 6A).

[0040] As in the comparative example shown in Figure 5, even if the second reinforcing rib 10 is provided at the corner between the rib and the first reinforcing rib 8, the joining range in the width direction to the joint plate 6 remains narrow, so the joint plate 6 cannot suppress deformation and the joint structure cannot exhibit its load-bearing performance.

[0041] On the other hand, according to the reinforcing structure of the joint plate 6 of this embodiment shown in Fig. 3, the second reinforcing rib 10 is provided on the joint plate 6 side, so that the squareness of the corner between the first reinforcing rib 8 and the joint plate 6 can be maintained. Therefore, deformation of the joint plate 6 can be suppressed (see symbol 6A), and the joint structure can exhibit load-bearing performance.

[0042] Specifically, the second reinforcing rib 10 shown in Fig. 3 has a widthwise joining range to the joint plate 6 that is more than twice (more than three times in this embodiment) the joining range at the end face of the first reinforcing rib 8. This makes it possible to suppress deformation of the joint plate 6. Furthermore, this reinforcing structure makes it possible to suppress deformation of the joint plate 6 simply by adding the second reinforcing rib 10, which is more economical than manufacturing a stronger steel frame 2 by, for example, increasing the thickness of the joint plate 6.

[0043] As described above, the segment 1 of the present embodiment comprises an arc-shaped steel frame 2 formed in a box shape with an open inner periphery, and concrete 3 poured inside the steel frame 2. The steel frame 2 is provided on the outer periphery and comprises a skin plate 4 extending in the circumferential direction, a pair of main girders 5 provided on both sides of the skin plate 4 in the width direction, a pair of joint plates 6 provided on both sides of the skin plate 4 in the circumferential direction, a rib 7 extending in the width direction and connecting the pair of main girders 5, a first reinforcing rib 8 extending in the circumferential direction and connecting the rib 7 to the joint plate 6, and a second reinforcing rib 10 connecting the first reinforcing rib 8 to the joint plate 6 at the corner between the first reinforcing rib 8 and the joint plate 6. This configuration improves the load-bearing capacity of the segment 1 and reduces manufacturing costs.

[0044] In this embodiment, the joint plate 6 is formed with an insertion hole 6a in which the joint member is to be installed, the concrete 3 is formed with a recess 3a in which the joint member is to be placed at a position corresponding to the insertion hole 6a, the first reinforcing rib 8 is placed near the recess 3a, and the second reinforcing rib 10 is placed on the opposite side of the first reinforcing rib 8 from the recess 3a. With this configuration, the second reinforcing rib 10 can be placed so as not to interfere with the joint member placed in the recess 3a of the concrete 3.

[0045] In this embodiment, the second reinforcing rib 10 has a right-angled triangular shape when viewed in the thickness direction. This configuration allows the squareness of the corner between the first reinforcing rib 8 and the joint plate 6 to be maintained with the minimum necessary shape, which is economically advantageous.

[0046] The second reinforcing rib 10 may have a shape as shown in FIG.

[0047] Fig. 6 is an enlarged view showing the reinforcing structure of a joint plate 6 according to a modified example of the first embodiment of the present invention. Like Fig. 3, Fig. 6 is an enlarged view of the other circumferential end side of the segment 1 (the right side in Fig. 2), and shows the state in which the concrete 3 of the segment 1 has been removed to improve visibility.

[0048] The second reinforcing rib 10A shown in Fig. 6 has a plate shape extending at an angle of 45 degrees relative to the width direction when viewed in the thickness direction. With this configuration, similar to the second reinforcing rib 10 shown in Fig. 3 described above, the squareness of the corner between the first reinforcing rib 8 and the joint plate 6 can be suitably maintained.

[0049] (Second embodiment) Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0050] Fig. 7 is an enlarged view showing the reinforcing structure of a joint plate 6 according to a second embodiment of the present invention. Like Fig. 3, Fig. 7 is an enlarged view of the other circumferential end side of the segment 1 (the right side in Fig. 2), and shows the state in which the concrete 3 of the segment 1 has been removed to improve visibility.

[0051] 7, in the second embodiment, the first reinforcing ribs 8 are arranged in pairs to sandwich the insertion holes 6a of the joint plate 6. That is, the first reinforcing ribs 8 are provided in pairs at two locations, one end (upper side in FIG. 7) and the other end (lower side in FIG. 7) in the width direction, for the two insertion holes 6a of the joint plate 6.

[0052] The second reinforcing rib 10 is disposed on the opposite side of the insertion hole 6a of each of the pair of first reinforcing ribs 8. As described above, recesses 3a in the concrete 3 are formed on the insertion hole 6a side of each of the pair of first reinforcing ribs 8, and therefore the second reinforcing rib 10 is disposed on the opposite side of the first reinforcing rib 8 from the insertion hole 6a so as not to interfere with the joint member disposed in the recesses 3a.

[0053] According to the second embodiment having the above configuration, the joint plate 6 is formed with an insertion hole 6a through which the joint member is inserted, the first reinforcing ribs 8 are arranged in pairs on either side of the insertion hole 6a, and the second reinforcing ribs 10 are arranged on the opposite side of each of the pair of first reinforcing ribs 8 from the insertion hole 6a. With this configuration, the joining range of the first reinforcing ribs 8 and the second reinforcing ribs 10 to the joint plate 6 in the width direction is doubled compared to the first embodiment. Therefore, deformation of the joint plate 6 can be more reliably suppressed.

[0054] The second reinforcing rib 10 may have a shape as shown in FIG. 8 or FIG.

[0055] Fig. 8 is an enlarged view showing the reinforcing structure of a joint plate 6 according to a modified example of the second embodiment of the present invention. Like Fig. 3, Fig. 8 is an enlarged view of the other circumferential end side of the segment 1 (the right side in Fig. 2), and shows the state in which the concrete 3 of the segment 1 has been removed to improve visibility.

[0056] The second reinforcing rib 10A shown in Fig. 8 has a plate shape extending at an angle of 45 degrees relative to the width direction when viewed in the thickness direction. With this configuration, similar to the second reinforcing rib 10 shown in Fig. 7 described above, the squareness of the corner between the first reinforcing rib 8 and the joint plate 6 can be suitably maintained.

[0057] Fig. 9 is an enlarged view showing the reinforcing structure of a joint plate 6 according to another modified example of the second embodiment of the present invention. Like Fig. 3, Fig. 9 is an enlarged view of the other circumferential end side of the segment 1 (the right side in Fig. 2), and shows the state in which the concrete 3 of the segment 1 has been removed to improve visibility.

[0058] In the second reinforcing rib 10 shown in FIG. 9, the second reinforcing rib 10a located near the main girder 5 is smaller than the second reinforcing rib 10b located away from the main girder 5. Because the main girder 5 is joined to the joint plate 6, deformation of the joint plate 6 is small near the main girder 5. For this reason, making the second reinforcing rib 10a located near the main girder 5 smaller is more economically advantageous.

[0059] While the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0060] For example, in the above-described embodiments, a bolt is used as an example of a coupling member, and the insertion hole 6a of the coupling plate 6 is used as an example of a coupling installation portion where the coupling member is installed. However, the present invention is not limited to this configuration. The coupling member may be, for example, a flat steel plate-shaped male coupling fitting as shown in Japanese Patent No. 5097734, or a female coupling fitting that accepts the male coupling fitting, and the coupling installation portion may be the male coupling fitting or the female coupling fitting that is installed on the coupling plate 6. Furthermore, the coupling member may be, for example, a male coupling fitting with a plurality of teeth formed on its outer surface as shown in Japanese Patent No. 6425335, or a female coupling fitting that accepts the male coupling fitting, and the coupling installation portion may be the male coupling fitting or the female coupling fitting that is installed on the coupling plate 6.

[0061] Furthermore, for example, the configurations of the above-described embodiments and modifications can be combined or substituted as appropriate. [Explanation of symbols]

[0062] REFERENCE SIGNS LIST 1...segment, 2...steel frame, 3...concrete, 3a...recess, 4...skin plate, 5...main girder, 5a...insertion hole, 6...joint plate, 6a...insertion hole, 7...rib, 8...first reinforcing rib, 8...first reinforcing rib, 10...second reinforcing rib, 10A...second reinforcing rib, 10a...second reinforcing rib, 10b...second reinforcing rib

Claims

1. an arc-shaped steel frame formed in 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 the outer circumferential side and extending in the 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 sides of the skin plate in the circumferential direction; a rib extending in the width direction and connecting the pair of main beams; a first reinforcing rib extending in a circumferential direction and connecting the rib and the joint plate; a second reinforcing rib connecting the first reinforcing rib and the joint plate at a corner between the first reinforcing rib and the joint plate, The joint plate is provided with a joint installation portion on which a joint member is installed, the first reinforcing rib is disposed near the joint installation portion, The segment, characterized in that the second reinforcing rib is arranged on the opposite side of the first reinforcing rib from the joint installation portion side.

2. an arc-shaped steel frame formed in 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 the outer circumferential side and extending in the 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 sides of the skin plate in the circumferential direction; a rib extending in the width direction and connecting the pair of main beams; a first reinforcing rib extending in a circumferential direction and connecting the rib and the joint plate; a second reinforcing rib connecting the first reinforcing rib and the joint plate at a corner between the first reinforcing rib and the joint plate, The joint plate is provided with a joint installation portion on which a joint member is installed, The first reinforcing ribs are arranged in a pair to sandwich the joint installation portion, A segment characterized in that the second reinforcing rib is arranged on the side opposite the joint installation portion side of each of the pair of first reinforcing ribs.

3. The segment of claim 2 , wherein the second reinforcing ribs located closer to the main spar are smaller than the second reinforcing ribs located further from the main spar.

4. The segment according to any one of claims 1 to 3, wherein the second reinforcing rib has a right-angled triangular shape when viewed in the thickness direction.

5. The segment according to any one of claims 1 to 3, characterized in that the second reinforcing rib has a plate shape extending obliquely with respect to the width direction when viewed in the thickness direction.

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