Segment pieces, segment rings and tunnel linings

Abstract

To provide a segment piece, a segment ring, and a tunnel lining that can reduce the stress generated by concrete.SOLUTION: A segment piece 10 constituting a segment ring comprises a main body 20 mainly made of concrete, a plurality of main rebars 30 embedded inside the main body 20 and arranged so as to extend in the circumferential direction of the segment ring, a plurality of force distribution rebars 40 that are arranged so as to extend in the radial direction of the segment ring and in the axial direction of the segment ring and restrain the plurality of main rebars 30, and a plurality of compressed steel materials 50 formed in a rod shape and embedded so as to extend inward from a peripheral end surface 20f of the main body 20 toward the central portion. The plurality of compressed steel materials 50 have at least one of a plurality of inner peripheral side compressed steel materials 51 arranged on the inner peripheral side in the radial direction and a plurality of outer peripheral side compressed steel materials 52 arranged on the outer peripheral side. The plurality of compressed steel materials 50 have a cover thickness equal to or higher than that of the force distribution rebar 40 in the radial direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a segment piece, a segment ring, and a tunnel lining used as a lining material for a tunnel or the like. [Background technology]

[0002] In recent years, the shield tunneling method has become established in the construction of subways, road tunnels, water supply and sewerage, power and communication cable tunnels, utility conduits, etc. In this shield tunneling method, RC (Reinforced-Concrete) segments are used as the lining for the excavation surface.

[0003] RC segments bear axial compressive forces through concrete and reinforcing bars. The segment pieces that make up RC segments have main reinforcing bars arranged inside the concrete of the main body. However, the main body of a conventional segment piece is the end of the main body, and the main reinforcing bars do not extend to the joints that connect the segment pieces to each other. Therefore, the joints of conventional segment pieces bear compressive forces only through the concrete. Therefore, segment pieces in which steel materials are installed in the joints have been proposed (see, for example, Patent Document 1).

[0004] When steel material is installed in the joint, the compressive force acting on the joint can be borne by the concrete and the steel material. Therefore, a segment piece in which steel material is installed in the joint can reduce the stress generated in the concrete, and can be thinner than a conventional segment piece in which steel material is not installed in the joint. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-12239 A Summary of the Invention [Problem to be solved by the invention]

[0006] There have been structural proposals in the past in which steel materials are installed in joints to reduce the stress load on the concrete by the concrete and the steel materials, as in Patent Document 1. However, there were no details on what kind of steel materials should actually be installed, in what positions, or to what depth, and no verification tests had been conducted, so there was little evidence on how the steel materials should be installed.

[0007] The present invention is devised to solve the above-mentioned problems, and provides a segment piece, a segment ring, and a tunnel lining that can reduce the stress generated in concrete by specifying the manner in which steel materials are installed. [Means for solving the problem]

[0008] The segment pieces according to the present invention are segment pieces that are arranged in an annular shape and connected to each other in the circumferential direction to constitute a cylindrically formed segment ring that covers the excavation surface of a tunnel, and include a main body mainly made of concrete, a plurality of main reinforcements that are embedded inside the main body and arranged to extend in the circumferential direction of the segment ring, a plurality of distribution reinforcements that are embedded inside the main body and arranged to extend in the radial direction of the segment ring and in the axial direction of the segment ring and constrain the plurality of main reinforcements, and a plurality of compression steel members formed in a rod shape that are embedded so as to extend inward from an end face in the circumferential direction of the main body toward the center, and the plurality of compression steel members are a plurality of inner circumference side compression steel members arranged on the inner circumference side in the radial direction and a plurality of outer circumference side compression steel members arranged on the outer circumference side in the radial direction. and at least one of the plurality of inner circumferential compression steel members and the plurality of outer circumferential compression steel members have a covering thickness in the radial direction equal to or greater than that of the plurality of distribution reinforcements, the plurality of main reinforcements include a plurality of inner circumferential main reinforcements arranged along the axial direction on the inner circumferential side in the radial direction and a plurality of outer circumferential main reinforcements arranged along the axial direction on the outer circumferential side in the radial direction, at least a portion of each of the plurality of inner circumferential main reinforcements is arranged between the plurality of inner circumferential main reinforcements in the axial direction, and at least a portion of each of the plurality of outer circumferential compression steel members is arranged between the plurality of outer circumferential main reinforcements in the axial direction, and at least one seal groove in which a seal member is arranged is formed on an end face of the main body, and the seal groove is formed so as to be recessed toward the inside of the main body and to extend in the axial direction. , at least on the outer periphery When at least one seal groove is formed only on the outer periphery side in the radial direction, the multiple outer periphery compression steel members are arranged outer than the seal groove, and when at least one seal groove is a multiple seal groove formed on the inner periphery side and the outer periphery side in the radial direction, the multiple inner periphery compression steel members are arranged inner than the seal groove formed on the innermost side, and the multiple outer periphery compression steel members are arranged outer than the seal groove formed on the outermost side.

[0009] The segment ring according to the present invention includes a plurality of segment pieces having the above-described configuration, the plurality of segment pieces being arranged in an annular shape and connected to each other in the circumferential direction.

[0010] The tunnel lining according to the present invention has a plurality of segment rings having the above-described configuration, the plurality of segment rings being connected in series in the direction in which the tunnel extends. Effect of the Invention

[0011] In the segment piece of the present invention, the multiple inner circumference compression steel members and the multiple outer circumference compression steel members have a cover thickness equal to or greater than that of the distribution reinforcement. With this configuration, the compression steel members are arranged on the end side of the segment piece in the radial direction of the segment ring. In other words, the compression steel members are arranged on the outer end of the segment piece in the radial direction of the segment ring. The strength of the segment piece can be ensured as the steel members are arranged on the outer end like main reinforcement, so the segment piece having the above configuration can reduce the stress generated in concrete. [Brief description of the drawings]

[0012] [Figure 1] 1 is a conceptual diagram of a segment ring according to an embodiment viewed in the axial direction. FIG. [Diagram 2] FIG. 2 is a perspective view conceptually illustrating a segment ring according to an embodiment. [Diagram 3] FIG. 4 is a conceptual diagram of a segment piece according to the embodiment as viewed in a radial direction of a segment ring. [Figure 4] FIG. 4 is a conceptual diagram of the segment piece as viewed from the cross section of the segment piece shown in FIG. 3 along line AA. [Diagram 5] 4 is a side view of the segment piece shown in FIG. 3 as viewed from the circumferential direction of the segment ring. [Figure 6] FIG. 13 is an enlarged view of a joint portion of a segment piece in which no compression steel material is installed. [Figure 7]FIG. 4 is an enlarged view of a joint portion of a segment piece where compression steel is installed. [Figure 8] FIG. 2 is an enlarged view showing an example of a compression steel material. [Figure 9] This figure shows the relationship between the length of compression steel, experimental values, and theoretical values ​​for an RC structure. [Figure 10] This is a diagram showing the relationship between the length of compression steel and concrete stress (experimental values). [Figure 11] FIG. 11 is a conceptual diagram of a modified example of a segment piece viewed from the circumferential direction of a segment ring. [Figure 12] FIG. 2 is a conceptual diagram of a tunnel lining according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the segment piece 10, the segment ring 100, the tunnel lining 200, and the like according to the embodiments will be described with reference to the drawings. In the following drawings including FIG. 1, the relative dimensional relationship and shape of each component may differ from the actual ones. In addition, in the following drawings, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification. In addition, to facilitate understanding, terms indicating directions (e.g., up, down, left, right, front, rear, front and back, etc.) are used as appropriate, but these notations are for the convenience of explanation and do not limit the arrangement, direction, or orientation of devices, instruments, parts, etc.

[0014] Embodiment [Segment Ring 100] FIG. 1 is a conceptual diagram of a segment ring 100 according to an embodiment as viewed in an axial direction AD. FIG. 2 is a perspective view conceptually showing the segment ring 100 according to an embodiment. The segment ring 100 will be described with reference to FIGS. 1 and 2. Note that the axial direction AD shown in FIGS. 1 and 2 represents the axial direction of the segment ring 100, and the circumferential direction CD represents the circumferential direction of the segment ring 100. The radial direction RD represents the radial direction of the segment ring 100, the Y1 side represents the inner peripheral side of the segment ring 100, and the Y2 side represents the outer peripheral side of the segment ring 100.

[0015] The segment ring 100 is a structure that covers the excavation surface in a construction method such as a shield tunneling method. The segment ring 100 is formed in a tubular shape. The segment ring 100 is formed, for example, in a cylindrical shape, but is not limited to a cylindrical shape. The tunnel body is constructed by connecting a plurality of segment rings 100 along the direction in which the tunnel extends. More specifically, the tunnel body is constructed in the shield tunneling method by arranging the segment rings 100 one circumference (one ring) of the cross section of the tunnel. Therefore, the segment ring 100 constitutes one unit in the tunnel body in the direction in which the tunnel extends.

[0016] [Segment piece 10] The segment pieces 10 are arranged in an annular shape and connected to each other in the circumferential direction CD to form a cylindrical segment ring 100 that covers the excavation surface of the tunnel. The segment ring 100 is divided into a plurality of components in the circumferential direction CD. These components are the segment pieces 10. When viewed in the axial direction AD of the segment ring 100, the segment pieces 10 are formed in an arc shape and in a curved shape. A plurality of segment pieces 10 are arranged in an annular shape, and adjacent segment pieces 10 are connected to each other to form the segment ring 100. Note that all of the segment pieces 10 are not necessarily formed to be the same size in the circumferential direction CD.

[0017] FIG. 3 is a conceptual diagram of the segment piece 10 according to the embodiment, viewed in the radial direction RD of the segment ring 100. FIG. 4 is a conceptual diagram of the segment piece 10 viewed from the cross section of the segment piece 10 shown in FIG. 3 taken along the line AA. FIG. 5 is a side view of the segment piece 10 shown in FIG. 3 viewed from the circumferential direction CD of the segment ring 100. FIG. 5 shows the positional relationship of each component when the segment piece 10 is viewed from the side. Note that FIG. 5 shows the internal components of the segment piece 10 with dotted lines. FIG. 6 is an enlarged view of the joint portion 12 of the segment piece 10L in which the compression steel material 50 is not installed. Note that in FIG. 3 to FIG. 6, the presence of reinforcing bars and compression steel materials arranged inside the concrete are shown in a see-through manner in order to clarify the internal structure of the segment piece 10. The structure of the segment piece 10 will be further described with reference to FIG. 3 to FIG. 6.

[0018] The segment piece 10 has an RC structure (reinforced concrete structure). The segment piece 10 has a main body 20, a plurality of main reinforcements 30, a plurality of distribution reinforcements 40, and a plurality of compression steel members 50.

[0019] (Main body 20) The main body 20 is a block-shaped structure mainly made of concrete. The main body 20 is curved in an arc shape when viewed from the axial direction AD of the segment ring 100. The main body 20 is a three-dimensional structure in which an arc-shaped plane having a width in the radial direction RD is continuous in the axial direction AD. In other words, the main body 20 is a rectangular parallelepiped curved in an arc shape.

[0020] The main body 20 has an inner circumferential side wall 20a that forms the wall surface on the inner circumferential side (Y1 side) of the segment ring 100, and an outer circumferential side wall 20b that forms the wall surface on the outer circumferential side (Y2 side) of the segment ring 100. The inner circumferential side wall 20a forms the internal space of the tunnel. The outer circumferential side wall 20b forms the wall on the outer circumferential side (Y2 side) of the tunnel, and forms the surface on the side that is disposed along the excavation face of the tunnel.

[0021] The main body 20 has an axial end face 20c that constitutes a wall surface at one end and an axial end face 20d that constitutes a wall surface at the other end in the axial direction AD of the segment ring 100. The axial end face 20c and the axial end face 20d form a vertical cross section with respect to the extension direction of the tunnel. A tunnel lining 200, which will be described later, is formed by connecting the segment rings 100 together as the axial end faces 20c and 20d abut against each other.

[0022] The main body 20 has a circumferential end face 20e that constitutes a wall surface at one end and a circumferential end face 20f that constitutes a wall surface at the other end in the circumferential direction CD of the segment ring 100. The segment ring 100 is formed by connecting the circumferential end face 20e and the circumferential end face 20f and connecting the segment pieces 10 together.

[0023] At least one seal groove 23 in which a seal member is disposed is formed on the axial end face 20c, the axial end face 20d, the circumferential end face 20e, and the circumferential end face 20f of the main body part 20. The seal groove 23 is formed to be recessed toward the inside of the main body part 20. The seal groove 23 formed on the circumferential end face 20e and the circumferential end face 20f is formed to extend in the axial direction AD of the segment ring 100. The seal groove 23 formed on the axial end face 20c and the axial end face 20d is formed to extend in the circumferential direction CD of the segment ring 100. The main body part 20 has a seal groove 23 formed at least on the outer circumferential side (Y2 side) of the radial direction RD of the segment ring 100. The main body part 20 may further have a seal groove 23 formed on the inner circumferential side (Y1 side) of the radial direction RD of the segment ring 100. A seal member (not shown) is attached to this seal groove 23. The sealing member is, for example, a water-swellable sealing material, but is not limited to a water-swellable sealing material.

[0024] (Main reinforcement 30) The multiple main reinforcements 30 are embedded inside the main body 20 as main steel materials, and are arranged to extend in the circumferential direction CD of the segment ring 100. The main reinforcements 30 are, for example, reinforcing bars. The segment piece 10 shown in Figs. 3 to 5 has nine main reinforcements 30 along the axial direction AD of the segment ring 100 and two main reinforcements 30 along the radial direction RD of the segment ring 100, but the number of main reinforcements 30 is not limited to this number.

[0025] The main reinforcements 30 include at least a plurality of inner-periphery-side main reinforcements 31 arranged along the axial direction AD of the segment ring 100 and disposed on the innermost periphery in the radial direction RD, and a plurality of outer-periphery-side main reinforcements 32 arranged along the axial direction AD and disposed on the outermost periphery in the radial direction RD.

[0026] 3 and 4, the length of the main reinforcement 30 in the circumferential direction CD is shorter than the length of the main body portion 20 in the circumferential direction CD. Therefore, as shown in the segment piece 10L in Fig. 6, there are gaps between both ends of the main reinforcement 30 and the circumferential end faces 20e and 20f of the main body portion 20. In other words, the main reinforcement 30 does not extend to the joint portions 12, which are the ends of the main body portion 20 and which connect the segment pieces 10 to each other.

[0027] (Strengthening bar 40) The distribution reinforcement 40 is embedded inside the main body 20 and arranged to extend in the radial direction RD and axial direction AD of the segment ring 100, and restrains the multiple main reinforcements 30. The distribution reinforcement 40 is a hoop reinforcement and a tie reinforcement that restrains the main reinforcements 30. The distribution reinforcement 40 surrounds and restrains the inner circumferential side main reinforcement 31 and the outer circumferential side main reinforcement 32 from the outside. A plurality of distribution reinforcement 40 are provided in the direction in which the main reinforcement 30 extends. The segment piece 10 shown in Figs. 3 to 5 has nine distribution reinforcement 40 along the circumferential direction CD of the segment ring 100, but the number of distribution reinforcement 40 is not limited to this number.

[0028] (Compression steel 50) The compression steel materials 50 are embedded so as to extend from the circumferential end faces 20e and 20f, which are the end faces in the circumferential direction CD of the main body portion 20, toward the central portion 20h into the main body portion 20. The compression steel materials 50 are embedded as reinforcing steel materials inside the main body portion 20. In the segment ring 100, the compression force generated between adjacent segment pieces 10 is transmitted to the compression steel materials 50, and the force transmitted to the compression steel materials 50 is dispersed from the compression steel materials 50 to the surrounding concrete.

[0029] The compression steel material 50 is formed in a rod shape. The compression steel material 50 is, for example, a reinforcing bar or a deformed steel bar. The segment piece 10 shown in Fig. 3 to Fig. 5 has eight compression steel materials 50 along the axial direction AD of the segment ring 100 and two compression steel materials 50 along the radial direction RD of the segment ring 100, but the number of compression steel materials 50 is not limited to this number.

[0030] 7 is an enlarged view of the joint portion 12 of the segment piece 10 in which the compression steel material 50 is installed. The compression steel material 50 has at least one of a plurality of inner circumference-side compression steel materials 51 arranged on the inner circumference side (Y1 side) in the radial direction RD and a plurality of outer circumference-side compression steel materials 52 arranged on the outer circumference side (Y2 side) in the radial direction RD.

[0031] The multiple inner periphery compression steel members 51 and the multiple outer periphery compression steel members 52 have a covering thickness in the radial direction RD equal to or greater than that of the multiple reinforcing bars 40. That is, as shown in Fig. 7, the covering thickness T1 of the inner periphery compression steel members 51 arranged on the inner periphery side (Y1 side) of the segment piece 10 is equal to or greater than the covering thickness T2 of the reinforcing bars 40 on the inner periphery side (Y1 side) of the segment piece 10. Similarly, the covering thickness T3 of the outer periphery compression steel members 52 arranged on the outer periphery side (Y2 side) of the segment piece 10 is equal to or greater than the covering thickness T4 of the reinforcing bars 40 on the outer periphery side (Y2 side) of the segment piece 10.

[0032] As shown in Fig. 5, in an area 45 surrounded by at least one of the multiple distribution reinforcements 40 arranged around the multiple main reinforcements 30, the multiple inner compression steel members 51 are arranged at the innermost periphery in the radial direction RD among the positions where the multiple compression steel members 50 can be arranged. Similarly, in an area 45 surrounded by at least one of the multiple distribution reinforcements 40 arranged around the multiple main reinforcements 30, the multiple outer compression steel members 52 are arranged at the outermost periphery in the radial direction RD among the positions where the multiple compression steel members 50 can be arranged. In Fig. 5, the area 45 is shown as an area hatched with dotted lines.

[0033] 5, at least a portion of each of the inner circumferential side compression steel members 51 is disposed between the inner circumferential side main reinforcements 31 in the axial direction AD. At least a portion of each of the outer circumferential side compression steel members 52 is disposed between the outer circumferential side main reinforcements 32 in the axial direction AD.

[0034] As shown in FIG. 5, the multiple inner compression steel members 51 are arranged on the inner circumferential side (Y1 side) of the seal groove 23 formed on the innermost circumferential side (Y1 side). The multiple outer compression steel members 52 are arranged on the outer circumferential side (Y2 side) of the seal groove 23 formed on the outermost circumferential side (Y2 side). It is desirable that the compression steel members 50 are arranged at the outer end of the main body 20 as far as possible in the radial direction RD, but they may be formed close to the outside of the two seal grooves 23 so as to be adjacent to the two seal grooves 23. The compression steel members 50 are not limited to this configuration. For example, the multiple inner compression steel members 51 may be arranged on the outer circumferential side (Y2 side) of the seal groove 23 formed on the innermost circumferential side (Y1 side). The multiple outer compression steel members 52 may be arranged on the inner circumferential side (Y1 side) of the seal groove 23 formed on the outermost circumferential side (Y2 side). That is, the multiple inner circumferential compression steel members 51 and the multiple outer circumferential compression steel members 52 may be disposed between the two seal grooves 23.

[0035] 5, in a cross section along the axial direction AD and radial direction RD of the main body 20, the thickness of the main body 20 in the radial direction RD is defined as a cross-sectional thickness ST. In this case, the multiple inner compression steel members 51 are arranged in a range from the inner side wall 20a to one-third of the cross-sectional thickness ST. The multiple outer compression steel members 52 are arranged in a range from the outer side wall 20b to one-third of the cross-sectional thickness ST.

[0036] 8 is an enlarged view showing an example of the compression steel material 50. The compression steel material 50 has a straight portion 56 extending linearly from the end face of the circumferential end face 20e or the circumferential end face 20f, and an inclined portion 57 provided at a tip end 56a of the straight portion 56 and inclined with respect to the extension direction of the straight portion 56.

[0037] The length L of each of the multiple compression steel materials 50 is formed to be 12 times or more the length of the steel bar diameter D of the compression steel material 50. The length L of the compression steel material 50 is the length along the direction in which the compression steel material 50 extends. Therefore, the length L of the compression steel material 50 is the total length of the length L1 of the straight portion 56 and the length L2 of the inclined portion 57. Since the load that the compression steel material 50 can bear varies depending on the cross-sectional area of ​​the diameter, the force shared by the compression rebar is determined by specifying the length L of the compression steel material 50 according to the magnification factor with respect to the rebar diameter, and the force with which the stress applied to the concrete is dispersed is determined.

[0038] As described above, there have been structural proposals in the past in which steel materials are installed in the joints 12 to reduce the stress load on the concrete by the concrete and the steel materials. However, there are no details on what kind of steel materials should actually be installed and to what depth, and no verification tests have been conducted, so the manner in which the steel materials should be installed is poorly justified. This time, the inventors conducted a verification test by changing the installation length of the compression steel materials 50. The verification test was conducted to verify how long the installation length of the compression steel materials 50 is required to reduce the stress generated in the concrete. The installation length of the compression steel materials 50 is also the embedment length of the compression steel materials 50.

[0039] FIG. 9 is a diagram showing the relationship between the length of the compression steel 50, the experimental value, and the theoretical value in an RC structure. FIG. 10 is a diagram showing the relationship between the length of the compression steel 50 and the concrete stress (experimental value and theoretical value). The verification test was conducted to confirm the effectiveness of the deformed reinforcing bar compression steel 50 by using the length L of the compression steel 50 as a parameter. The verification test was conducted by using the rebar diameter as the bar diameter D and setting the length L of the compression steel 50 to a range of 9 to 15 times the rebar diameter. Specifically, the stress generated in the concrete was measured when the length L of the compression steel 50 was set to 9, 12, and 15 times the rebar diameter. The verification test measured the generated stress when an axial compressive force of 4000 kN and a bending moment of 480 kN·m were applied. The results of the verification test are shown in FIG. 9 and FIG. 10.

[0040] From the test results, the effect of the compression steel material 50 is realized according to the theoretical value in RC structures when the length L of the compression steel material 50 is approximately 12 times or more the diameter of the rebar. Therefore, as a result of the verification test, the inventors confirmed that when rebar is used for the compression steel material 50, the effect is realized when the length L is 12 times or more the diameter of the rebar. The same verification test was conducted twice, and the reproducibility was confirmed.

[0041] 3 to 5, the segment piece 10 may have a plurality of base portions 60. The base portions 60 are formed in a flat plate shape. However, the shape of the base portions 60 is not limited to being formed in a flat plate shape. The base portions 60 may be formed in an angle shape, for example.

[0042] As shown in Fig. 5, the base 60 is disposed in the segment piece 10 so as to be exposed at the circumferential end face 20e and the circumferential end face 20f. Each of the multiple bases 60 is connected to each of the multiple compression steel materials 50. Each of the multiple compression steel materials 50 has an end portion on the circumferential end face 20e or circumferential end face 20f side connected to the base 60. The base 60 and the compression steel materials 50 are fixed by welding. The base 60 is used for positioning the compression steel materials 50 when they are disposed in the main body portion 20, and is used in the manufacture of the main body portion 20 when the compression steel materials 50 are embedded in concrete.

[0043] 11 is a conceptual diagram of a modified segment piece 10 as viewed in the circumferential direction CD of the segment ring 100. In the modified segment piece 10, the shape of a base portion 60A is different from the shape of the base portion 60 described above.

[0044] The base portion 60A is formed in a flat plate shape and is formed in an elongated shape in the axial direction AD of the segment ring 100. Each of the multiple base portions 60A is connected to multiple compression steel materials 50. The multiple compression steel materials 50 have their ends on the circumferential end face 20e or circumferential end face 20f side connected to the base portion 60A. The multiple compression steel materials 50 are arranged along the longitudinal direction of the base portion 60A. That is, the multiple compression steel materials 50 are connected to the base portion 60A formed in an elongated shape.

[0045] As shown in Fig. 4, Fig. 5 and Fig. 8, the base 60 and the base 60A are exposed from end faces such as the circumferential end face 20e and the circumferential end face 20f, and the exposed faces of the base 60 and the base 60A are covered with a waterproofing agent 70. The waterproofing agent 70 is, for example, an elastic epoxy. The waterproofing agent 70 is applied so as to cover the base 60 and the base 60A exposed at the circumferential end face 20e and the circumferential end face 20f.

[0046] [Manufacturing segment piece 10] First, a formwork for the main body 20 is created. A base 60 to which compression steel materials 50 are welded is fixed by fasteners such as bolts to the end positions of the main body 20 in the circumferential direction CD. A reinforcing bar cage formed by the main reinforcement bars 30 and the distribution reinforcement bars 40 is placed in the formwork. Thereafter, concrete is poured into the formwork, and after the concrete has solidified, the main body 20 is removed from the formwork to form the segment pieces 10.

[0047] [Tunnel lining 200] 12 is a conceptual diagram of a tunnel lining 200 according to an embodiment. The tunnel lining 200 has a plurality of segment rings 100, which are formed by continuously connecting the plurality of segment rings 100 in the direction in which the tunnel extends. The tunnel lining 200 is used to configure tunnels that constitute, for example, subways, road tunnels, water supply and sewage, electricity, communication cable tunnels, utility tunnels, etc.

[0048] [Action and effect of segment piece 10] In the segment piece 10, the multiple inner periphery compression steel materials 51 and the multiple outer periphery compression steel materials 52 have a cover thickness equal to or greater than that of the reinforcing bars 40. With this configuration, the compression steel materials 50 are arranged on the end side of the segment piece 10 in the radial direction RD of the segment ring 100. That is, the compression steel materials 50 are arranged at the outer end of the segment piece 10 in the radial direction RD of the segment ring 100. Since the strength of the segment piece 10 can be ensured as the steel materials are arranged closer to the outer end like the main reinforcement 30, the segment piece 10 having the above configuration can reduce the stress generated in concrete.

[0049] Moreover, the multiple inner compression steel materials 51 are arranged at the innermost periphery in the radial direction RD among the positions where the multiple compression steel materials 50 can be arranged, and the multiple outer compression steel materials 52 are arranged at the outermost periphery in the radial direction RD among the positions where the multiple compression steel materials 50 can be arranged. The strength of the segment piece 10 can be ensured as the compression steel materials 50 are arranged closer to the outer end of the segment piece 10, so that the segment piece 10 having the above configuration can reduce the stress generated in concrete.

[0050] In the axial direction AD, at least a portion of each of the multiple inner compression steel materials 51 is disposed between the multiple inner main reinforcements 31, and at least a portion of each of the multiple outer compression steel materials 52 is disposed between the multiple outer main reinforcements 32. The strength of the segment piece 10 can be ensured as the compression steel materials 50 are disposed closer to the outer end of the segment piece 10, so that the segment piece 10 having the above configuration can reduce the stress generated in concrete.

[0051] Moreover, the main reinforcement 30 is generally arranged at the most advantageous position in the main body 20 from the viewpoint of responding to the stress generated in concrete. With the above-mentioned configuration, at least a portion of the inner circumference side compression steel material 51 and the outer circumference side compression steel material 52 is arranged at a position overlapping with the main reinforcement 30 in the axial direction AD. That is, the inner circumference side compression steel material 51 and the outer circumference side compression steel material 52 are arranged at a position substantially equal to the position where the main reinforcement 30 is arranged in the radial direction RD. Therefore, the inner circumference side compression steel material 51 and the outer circumference side compression steel material 52 are arranged at the most advantageous position in the main body 20 from the viewpoint of responding to the stress generated in concrete, similar to the main reinforcement 30. Therefore, the segment piece 10 having the above-mentioned configuration can reduce the stress generated in concrete.

[0052] Moreover, the multiple inner compression steel members 51 are arranged more inward than the seal groove 23 formed on the innermost side, and the multiple outer compression steel members 52 are arranged more outward than the seal groove 23 formed on the outermost side. The more the compression steel members 50 are arranged on the outer end of the segment piece 10, the more the strength of the segment piece 10 can be ensured. Therefore, the segment piece 10 having the above configuration can reduce the stress generated in concrete.

[0053] Moreover, the multiple inner compression steel members 51 are arranged within a range of one-third of the cross-sectional thickness ST from the inner side wall portion 20a, and the multiple outer compression steel members 52 are arranged within a range of one-third of the cross-sectional thickness ST from the outer side wall portion 20b. The strength of the segment piece 10 can be ensured as the compression steel members 50 are arranged closer to the outer end of the segment piece 10, so that the segment piece 10 having the above configuration can reduce the stress generated in concrete.

[0054] Each of the multiple compression steel materials 50 has a straight portion 56 formed in a straight line, and an inclined portion 57 provided at a tip end 56a of the straight portion 56 and inclined with respect to the extension direction of the straight portion 56. The main body 20 is formed in an arc shape, and if the compression steel material 50 were formed only with the straight portion 56, there is a possibility that it would interfere with the distribution reinforcement 40. By having the inclined portion 57, the compression steel material 50 can avoid interference with the distribution reinforcement 40. As a result, the compression steel material 50 can ensure the embedment length.

[0055] Moreover, the length L of each of the multiple compression steel materials 50 is formed to be 12 times or more the length of the steel bar diameter D. Therefore, as described above, it is possible to achieve the effect according to the theoretical value in the RC structure, and the segment piece 10 can reduce the stress generated in the concrete.

[0056] Moreover, the segment piece 10 has a base 60 formed in a flat plate shape, and the multiple compression steel materials 50 are each connected to the base 60. Since the compression steel materials 50 are connected to the base 60, positioning of the segment piece 10 during production becomes easy, and the manufacturability of the segment piece 10 can be improved.

[0057] Furthermore, the multiple compression steel members 50 are connected to the base 60A, and are arranged along the longitudinal direction of the base 60A. Since the base 60A is connected to the multiple compression steel members 50, the multiple compression steel members 50 can be positioned simultaneously. Therefore, the segment piece 10 having the base 60A can further improve the manufacturability.

[0058] Furthermore, the base 60 and the base 60A are exposed from the end faces, and the exposed surfaces of the base 60 and the base 60A are covered with a waterproofing agent 70. Generally, water may penetrate into the interface between concrete and steel. By applying the waterproofing agent 70 so as to cover the exposed surfaces of the base 60 and the base 60A, it is possible to prevent water penetration. As a result, the compression steel 50 can be positioned outside the seal groove 23 formed in the segment piece 10 in the radial direction RD.

[0059] The segment ring 100 has the segment piece 10 having the above-mentioned configuration. As a result, the segment ring 100 can obtain the same effects as the segment piece 10 according to the embodiment.

[0060] The tunnel lining 200 has the segment ring 100 having the above-mentioned configuration. As a result, the tunnel lining 200 can obtain the same effects as the segment piece 10 according to the embodiment.

[0061] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0062] 10 segment piece, 12 joint portion, 20 main body portion, 20a inner circumferential wall portion, 20b outer circumferential wall portion, 20c axial end face, 20d axial end face, 20e circumferential end face, 20f circumferential end face, 20h center portion, 23 seal groove, 30 main bar, 31 inner circumferential side main bar, 32 outer circumferential side main bar, 40 distribution bar, 45 area, 50 compression steel, 51 inner circumferential side compression steel, 52 outer circumferential side compression steel, 56 straight portion, 56a tip portion, 57 inclined portion, 60 base portion, 60A base portion, 70 waterproofing agent, 100 segment ring, 200 tunnel lining body, AD axial direction, CD circumferential direction, D steel bar diameter, RD radial direction, ST cross-sectional thickness, T1 cover thickness, T2 cover thickness, T3 Cover thickness, T4 cover thickness.

Claims

1. A segment ring is formed in a cylindrical shape and covers the excavation surface of a tunnel by being arranged in an annular shape and connected to each other in a circumferential direction. A main body portion mainly made of concrete; A plurality of main reinforcements are embedded inside the main body and arranged to extend in the circumferential direction of the segment ring; A plurality of reinforcing bars are embedded inside the main body and arranged to extend in the radial direction of the segment ring and in the axial direction of the segment ring, and constrain the plurality of main reinforcing bars; A plurality of compression steel members formed in a rod shape and embedded so as to extend inward from end faces in the circumferential direction of the main body portion toward a central portion; Equipped with The plurality of compression steel members are A plurality of inner circumferential compression steel members arranged on the inner circumferential side in the radial direction; A plurality of outer periphery compression steel members arranged on the outer periphery in the radial direction; At least one of The plurality of inner circumference side compression steel members and the plurality of outer circumference side compression steel members are The covering thickness in the radial direction is equal to or greater than the thickness of the plurality of reinforcing bars, The plurality of main reinforcements include: A plurality of inner circumferential side main reinforcements arranged along the axial direction on the inner circumferential side in the radial direction; A plurality of outer circumferential side main reinforcements arranged along the axial direction on the outer circumferential side in the radial direction; having Each of the plurality of inner circumferential compression steel members is At least a portion of the inner circumferential main reinforcements is disposed between the inner circumferential main reinforcements in the axial direction, Each of the plurality of outer periphery compression steel members is At least a portion of the outer periphery side main reinforcements is disposed between the outer periphery side main reinforcements in the axial direction, At least one seal groove in which a seal member is disposed is formed in the end surface of the main body, The seal groove is The recess is formed on the inner side of the main body and is formed at least on the outer circumferential side so as to extend in the axial direction, When the at least one seal groove is formed only on the outer circumferential side in the radial direction, The plurality of outer periphery compression steel members are The seal groove is disposed on the outer circumferential side. When the at least one seal groove is a plurality of seal grooves formed on an inner circumferential side and an outer circumferential side in the radial direction, The plurality of inner circumferential compression steel members are The seal groove is disposed on the inner circumferential side of the innermost seal groove, The plurality of outer periphery compression steel members are The segment piece is disposed on the outer circumferential side of the seal groove formed on the outermost side.

2. The plurality of inner circumferential compression steel members are the plurality of reinforcing bars are arranged along the axial direction on the radially inner circumferential side within an area surrounded by at least one of the plurality of reinforcing bars arranged around the plurality of main reinforcing bars; The plurality of outer periphery compression steel members are The segment piece according to claim 1 , wherein the first and second reinforcing bars are arranged along the axial direction on the outer circumferential side in the radial direction within an area surrounded by at least one of the plurality of reinforcing bars arranged around the plurality of main reinforcing bars.

3. The main body portion is an inner peripheral wall portion forming an inner peripheral wall surface of the segment ring; an outer peripheral wall portion forming an outer peripheral wall surface of the segment ring; having In a cross-sectional thickness, which is a radial thickness in a cross section along the axial and radial directions of the main body portion, The plurality of inner circumferential compression steel members are The inner circumferential wall portion is disposed within a range of one-third of the cross-sectional thickness, The plurality of outer periphery compression steel members are 3. The segment piece according to claim 1, wherein the segment piece is disposed within a range of one-third of the cross-sectional thickness from the outer peripheral side wall portion.

4. Each of the plurality of compression steel members is A linear portion extending from the end surface and formed linearly; an inclined portion provided at a tip end of the straight portion and inclined with respect to a direction in which the straight portion extends; The segment piece according to any one of claims 1 to 3, comprising:

5. Each of the plurality of compression steel members is It is a deformed steel bar, The length of each of the plurality of compression steel members is The segment piece according to any one of claims 1 to 4, which is formed to a length 12 times or more the diameter of the steel bar.

6. A plurality of base portions are disposed on the end surface and formed in a flat plate shape, Each of the plurality of base portions comprises: The segment piece according to any one of claims 1 to 5, wherein the segment piece is connected to each of the plurality of compression steel materials.

7. a plurality of base portions formed in a long, flat plate shape and disposed on the end surface so as to extend in the axial direction; Each of the plurality of base portions comprises: connected to the plurality of compression steel members, The plurality of compression steel members are The segment piece according to any one of claims 1 to 5, wherein the segment piece is arranged along the longitudinal direction of the plurality of base portions.

8. The plurality of base portions include The segment piece according to claim 6 or 7, wherein the base portions are exposed from the end faces, and the exposed faces of the base portions are covered with a waterproofing agent.

9. A plurality of segment pieces according to any one of claims 1 to 8, A segment ring is formed by arranging a plurality of the segment pieces in an annular manner and connecting them to each other in the circumferential direction.

10. A plurality of the segment rings according to claim 9, A tunnel lining in which a plurality of the segment rings are connected continuously in the direction in which the tunnel extends.

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