segment

Abstract

To provide a segment with a frame body that can be thoroughly filled with concrete.SOLUTION: A segment 1 comprises an arcuate frame body 5 with its inner peripheral side open and concrete C that is cast inside the frame body 5. The frame body 5 comprises a skin plate 4, a pair of girders 2, a pair of joint plates 3, and one or a plurality of tabular ribs 9. The skin plate 4 extends along the peripheral direction. The girders 2 are arranged on both sides in the width of the skin plate 4. The joint plates 3 are arranged on both sides in the peripheral direction of the skin plate 4. The ribs 9 extend along the aforesaid width direction and connect the pair of girders 2 with each other. The skin plate 4 is formed with a window opening portion through which concrete C is cast in the frame body 5. The rib 9 comprises a main plate part that is arranged along a part of the skin plate 4 facing the rib 9.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to segments.

Background Art

[0002] As a tunneling method, a shield method is generally used in which a shield machine excavates the ground and then sequentially installs arc-shaped segments in the circumferential and axial directions to construct a cylindrical tunnel wall (cylindrical wall).

[0003] The segment described in Patent Document 1 is a composite segment including a steel shell (frame) and concrete filled in the steel shell. The steel shell includes a skin plate, main girders, end plates, and a shape retaining material. This segment is produced by pouring concrete into the steel shell through a pouring port formed in the center of the skin plate and closing the pouring port with a lid.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above segment, the concrete does not sufficiently spread within the frame, and there is a possibility that the filling may be insufficient.

[0006] One aspect of the present invention aims to provide a segment capable of sufficiently filling the frame with concrete.

Means for Solving the Problems

[0007] A segment according to one aspect of the present invention comprises an arc-shaped frame with an open inner circumference, and concrete cast inside the frame, wherein the frame comprises a skin plate 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, and one or more plate-shaped ribs extending in the width direction and connecting the pair of main girders, wherein the skin plate has an opening window portion for casting the concrete into the frame, and the ribs have main plate portions positioned along the skin plate in the portion facing the ribs.

[0008] In the segment, the plurality of ribs may constitute one or more groups of ribs, and the plurality of ribs constituting the rib group may be arranged at intervals in the thickness direction of the skin plate.

[0009] A segment according to another aspect of the present invention comprises an arc-shaped frame with an open inner circumference, and concrete cast inside the frame, wherein the frame comprises a skin plate 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, and a plurality of plate-shaped ribs extending in the width direction and connecting the pair of main girders, wherein the skin plate has an opening window portion for casting the concrete into the frame, the plurality of ribs constitute one or more rib groups, and the plurality of ribs constituting the rib group are spaced apart in the thickness direction of the skin plate. [Effects of the Invention]

[0010] According to one aspect of the present invention, concrete can be sufficiently filled into the frame. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing a tunnel constructed with segments according to this embodiment. [Figure 2] This is a perspective view of a segment of the embodiment. [Figure 3] It is an exploded perspective view of the segment of the embodiment. [Figure 4] It is a schematic view showing a cross section of the segment of the embodiment. [Figure 5] It is a perspective view showing the manufacturing process of the segment of the embodiment. [Figure 6] It is a perspective view showing the manufacturing process following the previous figure. [Figure 7] It is a perspective view showing the manufacturing process following the previous figure. [Figure 8] It is a perspective view showing the manufacturing process following the previous figure. [Figure 9] It is a perspective view showing the manufacturing process following the previous figure. [Figure 10] It is a schematic view showing the process of placing concrete. [Figure 11] It is a schematic view showing the manufacturing process of the segment of the comparative form. [Figure 12] It is a schematic view showing a cross section of the segment having ribs of the first modification. [Figure 13] It is a schematic view showing a cross section of the segment having ribs of the second modification. [Figure 14] It is a schematic view showing a cross section of the segment of another embodiment.

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] [Segment] FIG. 1 is a perspective view showing a tunnel 100 constructed of segments 1 according to an embodiment of the present invention. As shown in FIG. 1, the segment 1 is formed in an arc shape that forms a part of the tunnel 100. The plurality of segments 1 are connected in the circumferential direction and the axial direction within the excavation hole. The plurality of segments 1 form a cylindrical wall 101 for constructing the tunnel 100 within this excavation hole.

[0014] On the inner peripheral surface of the cylindrical wall body 101, a surface covering member 102 is provided. On the outer peripheral surface of the cylindrical wall body 101, a backfill material 103 that fills the gap between the cylindrical wall body 101 and the excavation hole is provided. The circumferential direction of the tunnel 100 is the circumferential direction of the segment 1. The axial direction of the tunnel 100 is the width direction of the segment 1. The radial direction of the tunnel 100 is the thickness direction of the segment 1.

[0015] FIG. 2 is a perspective view of the segment 1. FIG. 3 is an exploded perspective view of the segment 1. FIG. 4 is a schematic view showing a cross section of the segment 1. FIG. 4 is a view showing the arrow I-I in FIG. 3. As shown in FIGS. 2 and 3, the segment 1 is a composite segment including a steel frame 5 and concrete C filled inside the steel frame 5. The steel frame 5 covers five surfaces of the concrete C excluding the inner peripheral surface.

[0016] The steel frame 5 has a skin plate 4, a pair of main girders 2, a pair of joint plates 3, lattice bars 6, and a plurality of ribs 9. The steel frame 5 is formed in an arc plate shape as a whole. The steel frame 5 is formed in a box shape with an open inner peripheral side. The steel frame 5 is a frame body formed of a metal such as steel.

[0017] The skin plate 4 is a member that contacts the wall surface of the excavation hole during tunnel construction, and has a curved plate shape that curves in an arc shape along the circumferential direction. The skin plate 4 is formed of a metal such as steel, for example. Hereinafter, the thickness direction of the skin plate 4 (the thickness direction of the segment 1) may be simply referred to as the "thickness direction". The circumferential direction of the skin plate 4 (the circumferential direction of the segment 1) may be simply referred to as the "circumferential direction". The width direction of the skin plate 4 (the width direction of the segment 1) may be simply referred to as the "width direction".

[0018] A pair of main girders 2 are arranged on the sides of the skin plate 4. The pair of main girders 2 are provided on both sides of the width direction of the skin plate 4. That is, one of the pair of main girders 2 is provided at one end of the skin plate 4 in the width direction. The other of the pair of main girders 2 is provided at the other end of the skin plate 4 in the width direction. The pair of main girders 2 protrude from both ends of the skin plate 4 in the width direction toward the inside (inner circumference) in the thickness direction of the skin plate 4. The pair of main girders 2 are arranged parallel to each other. The main girders 2 have a curved shape along the circumferential direction, similar to the skin plate 4. The main girders 2 are made of metal, such as steel. The pair of main girders 2 are provided with ring joints 7 as joints for connecting the segments 1 axially (width direction) (see Figure 2).

[0019] A pair of joint plates 3 are arranged at the ends of the skin plate 4. The pair of joint plates 3 are provided on both sides of the skin plate 4 in the circumferential direction. That is, one of the pair of joint plates 3 is provided at one end of the skin plate 4 in the circumferential direction. The other of the pair of joint plates 3 is provided at the other end of the skin plate 4 in the circumferential direction. The pair of joint plates 3 protrude from both ends of the skin plate 4 in the circumferential direction toward the inside (inner circumferential side) in the thickness direction of the skin plate 4. The joint plates 3 are rectangular in shape. The pair of joint plates 3 are arranged across a pair of main girders 2. The joint plates 3 are made of metal, such as steel. The pair of joint plates 3 are provided with segment joints 8 as joints for connecting segments 1 in the circumferential direction (see Figure 2).

[0020] The skin plate 4, the pair of main girders 2, and the pair of joint plates 3 are connected, for example, by welding.

[0021] As shown in Figure 3, the skin plate 4 comprises a skin plate body 4A, an opening frame 11, and a cover 14 (see Figure 2). A rectangular opening 10 is formed in the longitudinal center of the skin plate body 4A. The opening 10 is formed for pouring concrete C into the steel frame 5.

[0022] The opening frame 11 is positioned inside the opening 10. The opening frame 11 has a rectangular outer shape. The opening frame 11 has a rectangular opening window portion 11a. The opening window portion 11a is formed for pouring concrete C into the steel frame 5.

[0023] The opening frame 11 is made of a metal such as steel. Preferably, the four sides of the opening frame 11 are fixed to the edges of the opening 10 of the skin plate 4 by welding or the like. The opening frame 11 may have an exhaust port (not shown) for discharging gas from inside the steel frame 5. As shown in Figure 2, the lid 14 closes the opening window 11a.

[0024] As shown in Figures 3 and 4, multiple ribs 9 are stretched between a pair of main girders 2. The ribs 9 are long plates (rectangular) extending in the width direction of the skin plate 4. The ribs 9 are flat plates. The ribs 9 are made of metal, such as steel. One end of the rib 9 is joined to one main girder 2 by welding or the like. The other end of the rib 9 is joined to the other main girder 2 by welding or the like. The ribs 9 connect the main girders 2. The entire rib 9 is the main plate portion 13.

[0025] Multiple ribs 9 constitute multiple rib groups 15. More specifically, the multiple ribs 9 comprise a first rib group 15A and a second rib group 15B. The first rib group 15A and the second rib group 15B are examples of rib groups 15.

[0026] The first rib group 15A and the second rib group 15B are provided at intervals in the circumferential direction of the skin plate 4. The first rib group 15A is located closer to one end 5a in the circumferential direction than the center of segment 1. The second rib group 15B is located closer to the other end 5b in the circumferential direction than the center of segment 1.

[0027] The first rib group 15A comprises two ribs 9 aligned in the thickness direction of the skin plate 4. One of the two ribs 9 constituting the first rib group 15A is called the first rib 9A1. The other of the two ribs 9 is called the second rib 9A2. The two ribs 9 (9A1, 9A2) are spaced apart in the thickness direction of the skin plate 4. When viewed from the thickness direction of the skin plate 4, the two ribs 9 (9A1, 9A2) overlap in at least a portion of their positions. The two ribs 9 (9A1, 9A2) have the same shape as each other.

[0028] The first rib 9A1 is located in the internal space of the steel frame 5, closer to the inner circumference than the center in the thickness direction. The first rib 9A1 is located away from the inner surface C1 of the concrete C (see Figure 4) on the outer circumference side. The second rib 9A2 is located in the internal space of the steel frame 5, closer to the outer circumference than the center in the thickness direction. The second rib 9A2 is located away from the skin plate 4 on the inner circumference side.

[0029] The second rib group 15B comprises two ribs 9 aligned in the thickness direction of the skin plate 4. One of the two ribs 9 constituting the second rib group 15B is called the first rib 9B1. The other of the two ribs 9 is called the second rib 9B2. The two ribs 9 (9B1, 9B2) are spaced apart in the thickness direction of the skin plate 4. When viewed from the thickness direction of the skin plate 4, the two ribs 9 (9B1, 9B2) overlap in at least a portion of their positions. The two ribs 9 (9B1, 9B2) have the same shape as each other.

[0030] The first rib 9B1 is located in the internal space of the steel frame 5, closer to the inner circumference than the center in the thickness direction. The first rib 9B1 is located away from the inner surface C1 of the concrete C (see Figure 4) on the outer circumference side. The second rib 9B2 is located in the internal space of the steel frame 5, closer to the outer circumference than the center in the thickness direction. The second rib 9B2 is located away from the skin plate 4 on the inner circumference side.

[0031] It is preferable that the distances of the first rib 9A1 and the first rib 9B1 from the inner circumferential surface C1 of the concrete C (see Figure 4) are equal. It is preferable that the distances of the second rib 9A2 and the second rib 9B2 from the skin plate 4 are equal.

[0032] Ribs 9 (9A1, 9A2, 9B1, 9B2) are positioned along the portion of the skin plate 4 opposite to them. The thickness direction of ribs 9 is the same as the thickness direction of the skin plate 4 at the center of the portion opposite to ribs 9. "The portion of the skin plate 4 opposite to ribs 9" refers to the region where the skin plate 4 and ribs 9 overlap when viewed from the thickness direction of the skin plate 4.

[0033] Even if the thickness direction of the rib 9 is inclined with respect to the thickness direction of the skin plate 4 at the center of the portion facing the rib 9, if the inclination angle is within 10°, the rib 9 can be considered to be in a position aligned with the skin plate 4. The center of the skin plate 4 at the portion facing the rib 9 is, for example, the center when viewed from the width direction of the skin plate 4.

[0034] As shown in Figure 3, the grid reinforcement 6 is installed within the steel frame 5. The grid reinforcement 6 is constructed with main reinforcement and distribution reinforcement arranged in directions perpendicular to each other. More specifically, the grid reinforcement 6 comprises circumferential reinforcement 21 extending in the circumferential direction and widthwise reinforcement 22 extending in the width direction. The grid reinforcement 6 is embedded in concrete C.

[0035] As shown in Figure 4, concrete C is filled inside the steel frame 5. The inner circumferential surface C1 of segment 1 is formed by concrete C.

[0036] [Method for manufacturing segments] The manufacturing method for segment 1 will be explained with reference to Figures 5 to 10. This manufacturing method employs a back-casting method. In this manufacturing method, the casting mold 16 shown in Figure 5 is used. The main surface 16a of the casting mold 16 is a curved convex surface (circumferential surface) that conforms to the inner circumferential surface of segment 1 (see Figure 2).

[0037] As shown in Figure 5, the grid reinforcement bars 6 are housed inside the main frame 12 formed by the main girders 2 and joint plates 3. An opening frame 11 is installed in the main frame 12. As shown in Figure 6, the main frame 12 and the grid reinforcement bars 6 are placed on the main surface 16a of the casting mold 16. The opening on the inner circumference of the main frame 12 is closed by the main surface 16a of the casting mold 16.

[0038] As shown in Figure 7, the skin plate body 4A is installed on the outer circumferential side of the main frame 12. The opening on the outer circumferential side of the main frame 12 is closed by the skin plate body 4A. In this state, the longitudinal center of the skin plate body 4A is at the highest position.

[0039] As shown in Figure 8, concrete C is poured into the steel frame 5 through the opening window 11a using the hopper 18. The concrete C flows within the steel frame 5 and fills the space inside the steel frame 5.

[0040] Figure 10 is a schematic diagram showing the process of pouring concrete. As shown in Figure 10, the concrete C poured into the steel frame 5 from the opening window 11a flows circumferentially from the center of the steel frame 5 toward one end 5a and the other end 5b. Since the ribs 9 are positioned along the skin plate 4, the flow of concrete C is prevented from being obstructed by the ribs 9. The concrete C spreads throughout the entire internal space of the steel frame 5 and fills the steel frame 5.

[0041] As shown in Figure 9, after the concrete C is filled, it is cured to harden. After the concrete C has hardened, the opening window 11a is closed with the cover 14. The cover 14 is fixed to the opening frame 11 by welding or other means.

[0042] [Effects of the segment of the embodiment] In segment 1, the ribs 9 are positioned to follow the skin plate 4, which prevents the flow of concrete C from being obstructed by the ribs 9 when filling the steel frame 5 with concrete C. Therefore, concrete C can be sufficiently filled into the steel frame 5. Thus, the mechanical strength of segment 1 can be increased.

[0043] The rib group 15 comprises multiple ribs 9 arranged at intervals in the thickness direction of the skin plate 4, thereby increasing the mechanical strength of the segment 1.

[0044] For comparison, consider a segment in which the ribs are perpendicular to the skin plate. Figure 11 is a schematic diagram showing the manufacturing process of the comparative segment. As shown in Figure 11, in the comparative configuration segment, the ribs 59 are oriented perpendicular to the skin plate 4. The concrete C poured into the steel frame 5 flows circumferentially, but this flow may be obstructed by the ribs 59. Therefore, the filling of the steel frame 5 with concrete C may be insufficient.

[0045] The ribs may be configured as shown in Figures 12 and 13. Figure 12 is a schematic diagram showing a cross-section of a segment 31 having a rib 19, which is a first modified example of the rib 9. As shown in Figure 12, the rib 19 is formed in an L-shape, comprising a main plate portion 19a and a protruding plate portion 19b perpendicular to the main plate portion 19a. The main plate portion 19a is positioned along the skin plate 4 in the portion opposite to the rib 19. The protruding plate portion 19b protrudes from one end of the main plate portion 19a in the width direction toward the inner circumference of the segment 1. Because the rib 19 is L-shaped, it has high mechanical strength.

[0046] Figure 13 is a schematic diagram showing a cross-section of a segment 41 having a rib 29, which is a second modified example of the rib 9. As shown in Figure 13, the rib 29 comprises a main plate portion 29a and two protruding plate portions 29b perpendicular to the main plate portion 29a. The main plate portion 29a is oriented along the skin plate 4 in the portion facing the rib 29. The two protruding plate portions 29b each project outwards from one end and the other end of the main plate portion 29a in the width direction toward the outer circumference of the segment 1. Because the rib 29 has protruding plate portions 29b, it has high mechanical strength.

[0047] Figure 14 is a schematic diagram showing a cross-section of segment 51 in another embodiment. As shown in Figure 14, the multiple ribs 39 comprise a first rib group 35A and a second rib group 35B. The first rib group 35A comprises two ribs 39 (39A1, 39A2) aligned in the thickness direction of the skin plate 4. The two ribs 39 (39A1, 39A2) are spaced apart in the thickness direction of the skin plate 4. The second rib group 35B comprises two ribs 39 (39B1, 39B2) aligned in the thickness direction of the skin plate 4. The two ribs 39 (39B1, 39B2) are spaced apart in the thickness direction of the skin plate 4. Ribs 39 (39A1, 39A2, 39B1, 39B2) are positioned perpendicular to skin plate 4.

[0048] In segment 51, the multiple ribs 39 arranged in the thickness direction of the skin plate 4 are spaced apart, so that when filling the concrete C into the steel frame 5, the flow of concrete C is not obstructed by the ribs 39. As a result, the concrete C can be sufficiently filled into the steel frame 5. Thus, the mechanical strength of segment 51 can be increased.

[0049] Preferred embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the above embodiments. The shapes and combinations of the components shown in the above embodiments are examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0050] For example, segment 1 shown in Figure 2 comprises two rib groups 15, but the number of rib groups is not limited to two; it may be one or multiple (any number of two or more). The number of ribs constituting one rib group may be multiple (any number of two or more). Segment 1 comprises multiple ribs 9, but the number of ribs may be one or multiple. The direction of extension of the ribs is not limited to the width direction of the skin plate. The direction of extension of the ribs may be inclined with respect to the width direction of the skin plate. [Explanation of symbols]

[0051] 1, 31, 41, 51... Segments, 2... Main girder, 3... Joint plate, 4... Skin plate, 5... Steel frame (frame body), 9, 39... Ribs, 11a... Opening window section, 13, 19a, 29a... Main plate section, 15, 35... Rib group, 15A, 35A... First rib group, 15B, 35B... Second rib group.

Claims

1. An arc-shaped frame with an open inner circumference, The frame comprises concrete poured inside the frame, The aforementioned frame body is A skin plate extending in the circumferential direction, A pair of main girders provided on both sides in the width direction of the skin plate, A pair of joint plates provided on both sides of the skin plate in the circumferential direction, One or more plate-shaped ribs extending in the width direction, connecting a pair of main girders while being separated from the inner circumferential surface of the skin plate and the concrete and the joint plate, Equipped with, The skin plate has an opening window formed therein for pouring the concrete into the frame. The segment is characterized in that the rib comprises a main plate portion that is positioned to be aligned with the skin plate in the portion facing the rib.

2. The multiple ribs constitute one or more groups of ribs. The segment according to claim 1, characterized in that the plurality of ribs constituting the rib group are arranged at intervals in the thickness direction of the skin plate.

Images