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 inside 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; and joint members arranged on the pair of joint plates. The joint member comprises: an anchor material 11 embedded in the concrete 3. The rib 7 comprises: first hole parts 31 each inserted with the anchor material 11, and each constricting the inserted anchor material 11; and a second hole part 32 not inserted with the anchor material 11, and constricting the concrete 3.SELECTED DRAWING: Figure 3

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] Composite segments exhibit high load-bearing capacity by integrating the steel frame and concrete. One method of promoting integration of the steel frame and concrete is to use anchoring members such as stud dowels to restrain the concrete to the steel frame, but this increases the amount of steel used, making it uneconomical.

[0007] In addition, composite segments are equipped with joint members that connect the segments to a pair of joint plates on both sides in the circumferential direction. To improve the pull-out resistance of these joint members, anchor materials are sometimes attached to the joint members. However, if the joint members are pulled and the anchor materials move within the concrete, cracks can occur in the concrete.

[0008] 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]

[0009] 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, wherein 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, and joint members provided on the pair of joint plates, wherein the joint members comprise anchor materials embedded in the concrete, and the ribs comprise first hole portions into which the anchor materials are inserted and which restrain the inserted anchor materials, and second hole portions into which the anchor materials are not inserted and which restrain the concrete.

[0010] In the segment, the first hole portion and the second hole portion may have the same shape.

[0011] In the above segment, the first hole portion and the second hole portion may have a shape of a round hole or an elongated hole.

[0012] In the segment, the first hole portions may be spaced apart in the width direction, and at least one of the second hole portions may be provided between the first hole portions in the width direction.

[0013] In the segment, at least one of the second holes may be provided at a position different from that of the first hole in the thickness direction.

[0014] In the segment, at least one of the second hole portions may be provided closer to the opening of the steel frame than the first hole portion in the thickness direction.

[0015] The segment may have a fixing portion that fixes the anchor material inserted into the first hole to the rib. [Effects of the Invention]

[0016] 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]

[0017] [Figure 1] FIG. 1 is a perspective view showing a tunnel constructed with segments according to an embodiment of the present invention. [Figure 2] 3 is a cross-sectional view of one circumferential end of a segment according to an embodiment of the present invention, taken in the thickness direction. FIG. [Figure 3] FIG. 3 is a view taken along the line III-III in FIG. 2. [Figure 4] 10A and 10B are diagrams showing modified examples of ribs according to an embodiment of the present invention. [Figure 5] 10A and 10B are diagrams showing modified examples of ribs according to an embodiment of the present invention. [Figure 6] 10A and 10B are diagrams showing modified examples of ribs according to an embodiment of the present invention. [Figure 7] 10A and 10B are diagrams showing modified examples of the first hole portion and the second hole portion according to one embodiment of the present invention. [Figure 8] 10A and 10B are diagrams showing modified examples of the first hole portion and the second hole portion according to one embodiment of the present invention. [Figure 9] 10A and 10B are diagrams showing modified examples of the first hole portion and the second hole portion according to one embodiment of the present invention. [Figure 10] 10A and 10B are diagrams showing modified examples of the first hole portion and the second hole portion according to one embodiment of the present invention. [Figure 11] 10A and 10B are diagrams illustrating a modified example of the fixing portion according to the embodiment of the present invention. [Figure 12] 10A and 10B are diagrams illustrating a modified example of the fixing portion according to the embodiment of the present invention. [Figure 13] 10A and 10B are diagrams illustrating a modified example of the fixing portion according to the embodiment of the present invention. [Figure 14] FIG. 1 is an explanatory diagram illustrating the relationship between the behavior of anchor materials and cracks in concrete. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] FIG. 1 is a perspective view showing a tunnel 100 constructed with segments 1 according to one 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.

[0020] 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.

[0021] 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.

[0022] Fig. 2 is a cross-sectional view of one end of the segment 1 in the circumferential direction taken in the thickness direction according to one embodiment of the present invention. Fig. 3 is a view taken along the line III-III shown in Fig. 2. As shown in FIGS. 2 and 3, 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.

[0023] The segment 1 comprises an arc-shaped steel frame 2 formed in a box shape with an open inner periphery (the lower side of the paper in Figures 2 and 3), and concrete 3 poured inside the steel frame 2.

[0024] As shown in Figures 2 and 3, 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 this skin plate 4, and a pair of joint plates 6 arranged at the ends of the skin plate 4 (note that Figure 2 only shows the joint plate 6 on one end side of the circumferential direction of the segment 1).

[0025] In addition, a plurality of ribs 7 are provided between the pair of main girders 5. The skin plate 4, the pair of main girders 5, the pair of joint plates 6, and the ribs 7 are connected by welding.

[0026] 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.

[0027] The pair of main girders 5 are arranged parallel to each other and extend from both widthwise ends of the skin plate 4 inward in the thickness direction (toward the inner periphery), and have a curved shape along the circumferential direction, similar to the skin plate 4. The pair of main girders 5 are provided with joint members (not shown) that connect the segments 1 together in the width direction.

[0028] The pair of joint plates 6 are rectangular plates extending inward (toward the inner periphery) in the thickness direction from both circumferential ends of the skin plate 4, and are disposed between the pair of main girders 5 described above. The pair of joint plates 6 are provided with joint members 10 that connect the segments 1 in the circumferential direction. Although not shown, in this embodiment, the joint members 10 are provided in pairs on each joint plate 6, spaced apart in the width direction. The number and arrangement of the joint members 10 can be changed as appropriate depending on the specifications of the segments 1. For example, the joint members 10 may be arranged in two stages on the joint plate 6 in the thickness direction.

[0029] The coupling part 10 shown in Fig. 2 is a male coupling fitting that protrudes circumferentially outward from the coupling plate 6. The coupling part 10 of this embodiment is disposed approximately perpendicular to the plate surface of the coupling plate 6. Note that although the segment 1 shown in Fig. 2 is an A-type segment, in the case of a K-type segment that is inserted axially in a wedge-like shape at the end of the cylindrical portion of the cylindrical wall body 101, or in the case of B-type segments that are disposed on both circumferential sides of the K-type segment, the coupling part 10 and the coupling plate 6 may not be perpendicular. Furthermore, when the mating segment 1 to be connected is a male coupling fitting, the coupling part 10 may be a female coupling fitting that accepts the male coupling fitting.

[0030] The coupling member 10 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. Even in a sliding coupling structure such as that shown in Japanese Patent No. 5097734, the coupling member 10 and the coupling plate 6 may not be perpendicular, and may be attached at an angle.

[0031] The joint member 10 includes anchor materials 11 that are embedded in the concrete 3. The anchor materials 11 are formed, for example, from reinforcing bars. The material that constitutes the anchor materials 11 is not limited to reinforcing bars, and may be, for example, plate materials, tubular materials, stranded steel wires, bolts, etc. The anchor materials 11 are fixed to the joint member 10. The method for fixing the anchor materials 11 is not particularly limited, and they may be fixed, for example, by welding or using a jig. In this embodiment, one anchor material 11 is provided for one joint member 10, but the number and arrangement of the anchor materials 11 are not limited.

[0032] 3, the rib 7 is generally plate-shaped and extends in the width direction, with both ends fixed to a pair of main girders 5, and 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.

[0033] 2, circumferential reinforcing bars 21 extending in the circumferential direction are arranged in the gaps between the ribs 7 and the skin plate 4. In addition, circumferential reinforcing bars 21 extending in the circumferential direction are also arranged on the inner circumferential side of the ribs 7.

[0034] Furthermore, widthwise reinforcing bars 22 extending in the width direction are arranged in the gaps between the ribs 7 and the joint plates 6. The widthwise reinforcing bars 22 are arranged so as to intersect with and surround the circumferential reinforcing bars 21 arranged on the outer and inner circumferential sides of the ribs 7. Although only a portion of the widthwise reinforcing bars 22 is shown in FIG. 2 , the widthwise reinforcing bars 22 are arranged around the entire circumferential direction of the segment 1, as in, for example, Japanese Patent Nos. 5732215 and 59609424. The widthwise reinforcing bars 22 may be bent into a U-shape and intersect with either one of the circumferential reinforcing bars 21 arranged on the outer circumferential side or the inner circumferential side of the rib 7, and may have a three-dimensional shape bent so that both ends also intersect the rib 7.

[0035] As shown in Fig. 3, the rib 7 has first holes 31 into which anchor materials 11 are inserted and which restrain the inserted anchor materials 11, and second holes 32 into which no anchor materials 11 are inserted and which restrain the concrete 3. The first holes 31 and the second holes 32 are formed by penetrating the plate surface of the rib 7 facing in the circumferential direction.

[0036] In this embodiment, the first hole portion 31 and the second hole portion 32 have the same shape. However, the first hole portion 31 and the second hole portion 32 may have different shapes or sizes. In this embodiment, the first hole portion 31 and the second hole portion 32 have a circular hole shape. The inner diameter of this circular hole is formed to be at least larger than the outer diameter of the anchor material 11. However, if the inner diameter of the circular hole is too large, the restraining force of the anchor material 11 will be weakened, so it is advisable to determine the inner diameter of the circular hole taking into account the outer diameter of the anchor material 11.

[0037] The first holes 31 are provided in pairs spaced apart in the width direction. One second hole 32 is provided between the first holes 31 in the width direction. That is, the rib 7 of this embodiment has three holes spaced apart in the width direction, with anchor materials 11 inserted into the two holes (first holes 31) on both sides in the width direction, and the single hole (second hole 32) in the center in the width direction without an anchor material 11 inserted is filled with concrete 3. The number and arrangement of the holes can be changed as appropriate, as shown in the modified examples described later. The number and arrangement of the holes can be changed as appropriate depending on the size of the segment 1, and are not limited to the modified examples described later. For example, the first holes 31 and the second holes 32 may be round or elongated, may be arranged in multiple stages, or may not be aligned.

[0038] The rib 7 may have a configuration as shown in FIGS. 4 to 6 are diagrams showing modified examples of the rib 7 according to one embodiment of the present invention.

[0039] The rib 7 shown in FIG. 4 is formed in an L-shape having a first portion 7a extending in the thickness direction and a second portion 7b bending from the first portion 7a and extending to one side in the circumferential direction. The rib 7 shown in Figure 5 is formed in a T-shape having a first portion 7a extending in the thickness direction and a third portion 7c joined to the end of the first portion 7a and extending circumferentially from the first portion 7a on both sides. The rib 7 shown in Fig. 6 has a joint 7d joined to the skin plate 4 by welding. The L-shaped rib 7 shown in Fig. 4 and the T-shaped rib 7 shown in Fig. 5 may also have a joint 7d joined to the skin plate 4 by welding.

[0040] The first hole portion 31 and the second hole portion 32 may also have the configurations shown in FIGS. 7 to 10 are diagrams showing modified examples of the first hole portion 31 and the second hole portion 32 according to one embodiment of the present invention.

[0041] The first hole portion 31 and the second hole portion 32 shown in FIG. 7 have the shape of an elongated hole extending in the thickness direction. The first hole portion 31 and the second hole portion 32 shown in FIG. 8 have the shape of an elongated hole extending in the width direction. The first hole portions 31 and second hole portions 32 shown in FIGS. 7 and 8 may be arranged in a staggered manner so that their positions differ in the thickness direction.

[0042] 9 are provided in two stages in the rib 7, spaced apart in the thickness direction. Specifically, three holes are provided in the first stage on the outer periphery of the rib 7, spaced apart in the width direction, with two holes on both sides in the width direction being the first hole 31 and one hole in the center in the width direction being the second hole 32. Furthermore, three holes are provided in the second stage on the inner periphery of the rib 7, spaced apart in the width direction by the same distance as in the first stage, with these three holes being the second hole 32.

[0043] 10 are provided in a staggered pattern in two stages spaced apart in the thickness direction of the rib 7. Specifically, the rib 7 has three holes spaced apart in the width direction in the first stage on the outer periphery, with two holes on both sides in the width direction serving as first holes 31 and one hole in the center in the width direction serving as second hole 32. Furthermore, the rib 7 has two holes spaced apart in the thickness direction in the first stage on the inner periphery, with two holes located between the first hole 31 and the second hole 32 in the first stage and between the second hole 32 and another first hole 31 in the second stage, with these two holes serving as second hole 32.

[0044] Furthermore, the segment 1 may be provided with a fixing portion 30 for fixing the anchor material 11 to the rib 7, as shown in FIGS. 11 to 13 are diagrams showing modified examples of the fixing portion 30 according to one embodiment of the present invention.

[0045] The fixing portion 30 shown in FIG. 11 has a male thread portion 12 provided on the circumferential surface of the anchor material 11, and a female thread portion 31a provided in the first hole portion 31 into which the male thread portion 12 screws. The fixing portion 30 shown in Figure 12 has a male threaded portion 12 provided on the peripheral surface of the anchor material 11, a tapered washer 15 attached to the male threaded portion 12 that has passed through the first hole portion 31, and a nut 13 that seats on the plate surface of the rib 7 on the side opposite the coupling member 10 via the tapered washer 15. The fixing part 30 shown in Fig. 13 has a joining part 14 that joins the anchor material 11 inserted into the first hole part 31 to the rib 7 by welding. Note that although the anchor material 11 is welded directly to the rib 7 in Fig. 13, it may also be welded to the rib 7 via a member.

[0046] Next, the relationship between the behavior of the anchor material 11 and cracks in the concrete 3 will be described with reference to FIG. FIG. 14 is an explanatory diagram illustrating the relationship between the behavior of the anchor material 11 and cracks in the concrete 3.

[0047] As shown in Figure 14, when there is clearance at the joint between segments 1, the joint part 10 that connects the segments 1 in the circumferential direction will resist the load in a bent corner state. When the joint part 10 is pulled in this state, the bent corner of the joint part 10 will try to straighten out, and the anchor material 11 will behave as shown by the dotted line in Figure 14. When the anchor material 11 behaves in this way as shown in Figure 14, the concrete 3 will try to bulge radially inward, which may result in cracks in the concrete 3.

[0048] In contrast, as shown in Fig. 2, the segment 1 of this embodiment has first hole portions 31 formed in the rib 7, and the anchor materials 11 of the joint members 10 are inserted into these first hole portions 31, so that the anchor materials 11 can be restrained. Therefore, the behavior of the anchor materials 11 as shown in Fig. 14 is restricted, and the radial inward bulging of the concrete 3 due to the behavior of the anchor materials 11 is suppressed, so that cracks in the concrete 3 can be prevented.

[0049] Furthermore, as shown in Fig. 3, the segment 1 of this embodiment has second holes 32 in the ribs 7 that restrain the concrete 3 without inserting anchor materials 11. Providing second holes 32 in the ribs 7, which are generally provided as part of the structure of the steel frame 2, can promote integration with the concrete 3 without increasing the amount of steel used. Also, as shown in Fig. 2, by providing holes in the ribs 7 that are away from the joint members 10, the effect of preventing the concrete 3 from slipping can be obtained in the ribs 7 as well.

[0050] 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 widthwise sides of the skin plate 4, a pair of joint plates 6 provided on both circumferential sides of the skin plate 4, ribs 7 extending in the width direction and connecting the pair of main girders 5, and joint members 10 provided on the pair of joint plates 6. The joint members 10 comprise anchors 11 embedded in the concrete 3, and the ribs 7 comprise first holes 31 into which the anchors 11 are inserted and which restrain the inserted anchors 11, and second holes 32 into which the anchors 11 are not inserted and which restrain the concrete 3. This configuration improves the load-bearing capacity of the segment 1 and reduces manufacturing costs.

[0051] In this embodiment, the first hole portion 31 and the second hole portion 32 have the same shape. This configuration allows the first hole portion 31 and the second hole portion 32 to be manufactured in the same process, which is economically advantageous.

[0052] In this embodiment, the first hole 31 and the second hole 32 have a round or elongated hole shape. When the first hole 31 and the second hole 32 have a round hole shape, the restraining force of the anchor material 11 can be increased. When the first hole 31 and the second hole 32 have an elongated hole shape, the area filled with the concrete 3 increases, thereby increasing the effect of preventing the concrete 3 from slipping.

[0053] In this embodiment, the first holes 31 are spaced apart in the width direction, and at least one of the second holes 32 is located between the first holes 31 in the width direction. This configuration can suppress the movement of the anchor material 11 on both sides in the width direction, while also suppressing the prevention of displacement of the concrete 3.

[0054] In this embodiment, at least one of the second holes 32 is provided at a position different from that of the first hole 31 in the thickness direction (see FIGS. 9 and 10). With this configuration, the concrete 3 can be restrained in at least two stages in the thickness direction, thereby improving the slippage prevention effect of the concrete 3.

[0055] Moreover, in this embodiment, at least one of the second hole portions 32 is provided closer to the opening side of the steel frame 2 than the first hole portion 31 in the thickness direction (see FIG. 9). With this configuration, even if the anchor material 11 tries to move toward the inner diameter side as shown in FIG. 14, the concrete 3 is restrained by the second hole portion 32 arranged nearby, and therefore cracks caused by the bulging of the concrete 3 can be effectively suppressed.

[0056] Furthermore, in this embodiment, there is provided a fixing portion 30 that fixes the anchor material 11 inserted into the first hole portion 31 to the rib 7 (see FIGS. 11 to 13). With this configuration, the restraining force of the anchor material 11 can be increased.

[0057] 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.

[0058] For example, the configurations of the above-described embodiments and modifications may be combined or substituted as appropriate. [Explanation of symbols]

[0059] 1...segment, 2...steel frame, 3...concrete, 4...skin plate, 5...main girder, 6...joint plate, 7...rib, 7a...first part, 7b...second part, 7c...third part, 7d...joint, 10...joint member, 11...anchor material, 12...male threaded part, 13...nut, 14...joint, 21...circumferential reinforcing bar, 22...widthwise reinforcing bar, 30...fixing part, 31...first hole part, 31a...female threaded part, 32...second hole part

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 joint member provided on the pair of joint plates, The joint member includes an anchor material embedded in the concrete, The rib includes a first hole portion into which the anchor material is inserted and which restrains the inserted anchor material, and a second hole portion into which the anchor material is not inserted and which restrains the concrete, At least one of the second hole portions is provided closer to the opening side of the steel frame than the first hole portion in the thickness direction. A segment characterized by:

2. The segment according to claim 1 , wherein the first hole portion and the second hole portion have the same shape.

3. 3. The segment according to claim 2, wherein the first hole portion and the second hole portion have a shape of a round hole or an elongated hole.

4. The first holes are spaced apart in the width direction, The segment according to any one of claims 1 to 3, characterized in that at least one of the second hole portions is provided between the first hole portions in the width direction.

5. The segment according to any one of claims 1 to 4, wherein at least one of the second holes is provided at a position different from that of the first hole in the thickness direction.

6. The segment according to any one of claims 1 to 5, characterized in that it has a fixing portion that fixes the anchor material inserted into the first hole portion to the rib.

Images