Composite segment

Abstract

To provide a composite segment having a wider width in the tunnel axis direction, which is materialized with a structure configured to function as a composite unit with respect to a sectional force also in the tunnel axis direction.SOLUTION: A composite segment is constituted of a steel shell 1 and infilled concrete 2 filled in the steel shell 1, in an approximate arc shape along a natural ground of a tunnel in a side view, The steel shell 1 is constituted of girders 4, 4 arranged in a circumferential direction of the tunnel; joint plates 5, 5 arranged respectively between ends of the girders 4, 4: multiple longitudinal ribs 6,... arranged between the girders 4, 4; and a skin plate 8 arranged on an outer face side of the grid-shape frame 7 constituted of the girders 4, 4, the joint plates 5, 5 and the longitudinal ribs 6,... A pair of inner flanges 10, 10 are symmetrically fitted to facing side-surfaces of the girders 4, 4. The infilled concrete 2 has no reinforcement bars. Reinforcement ribs 9 are fitted to the longitudinal ribs 6,... Fall-prevention bars 12 are arranged inside the infilled concrete 2 for a purpose of preventing the infilled concrete 2 from falling off.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite segment used as a lining material for a shield tunnel, and in particular, the segment is configured so that the entire width direction thereof constitutes a composite structure, and functions as a composite structure not only against cross-sectional forces in the circumferential direction of the tunnel, but also against cross-sectional forces in the axial direction of the shield tunnel, thereby making it possible to provide a composite segment that is wide in the axial direction of the shield tunnel. [Background technology]

[0002] The lining of a shield tunnel (hereafter referred to as "tunnel") is generally constructed by assembling divided lining materials called segments inside the tunnel and fastening them with joints. For this reason, the more segments there are in the lining, the more construction work is required, and the more joints there are, the greater the risk of water leakage, among other issues.

[0003] For this reason, in recent years, wider segments have been used in the axial direction of the tunnel. While segments were previously around 1.5 m wide, there have recently been cases where 2.0 m wide segments have been used.

[0004] Furthermore, composite segments, which are composite structural materials made of steel and concrete, are used for tunnel linings that require particularly high strength. One known example of this type of composite segment is one made of a steel shell and concrete filling the steel shell.

[0005] The steel shell is formed into a rectangular frame body made up of a pair of side plates (main girders) and a pair of joint plates arranged respectively in the circumferential and axial directions of the tunnel, and a skin plate arranged on the outer side of the frame body (the natural ground side of the tunnel), and is formed into an approximately arc-shaped shape in side view along the ground of the tunnel.In particular, the skin plate is arranged on the outer side of the frame body, or on both the outer and inner sides, and the former is called a five-sided steel shell composite segment, and the latter is called a six-sided steel shell composite segment.

[0006] Also, for example, in the composite segment of Patent Document 1, multiple dowels are arranged on the inner surface of the skin plate, and multiple main reinforcements and distribution bars are arranged in a grid pattern in the circumferential and axial directions of the tunnel as reinforcing bars on the inner side of the filled concrete, and further multiple width stop bars are arranged at intervals in the circumferential direction of the tunnel between the main girders on both sides.

[0007] In the composite segments of Patent Document 3 and Non-Patent Document 1, there are no dowels on the inner surface of the skin plate, and the main girders on both sides are formed into a roughly U-shaped cross section by a web and a pair of flanges attached to the inside (opposite sides) of the web. Also, lattice reinforcing bars (crack prevention reinforcing bars) are arranged on the inner side of the filled concrete (internal concrete).

[0008] These composite segments are structurally integrated with concrete and steel, which allows for less steel to be used than steel segments, and are said to have the advantage of being stronger than RC segments of the same thickness. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-034799 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-083120 [Patent Document 3] Japanese Patent Application Publication No. 2017-089310 [Non-patent literature]

[0010] [Non-Patent Document 1] Atsushi Taniguchi, Takamasa Fukuda, Kenichi Horiguchi, "Concrete Engineering" Special Feature / Fusion of Concrete and Other Fields / 2. Ground and Concrete Structures Application of Composite (HB) Segments in the Shield Construction of the Central Circular Shinagawa Line, Taisei Corporation, Vol. 54, No. 9, September 2016, p. 883-p. 888 Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the former five-sided steel shell composite segments, the steel is generally concentrated at both ends of the segment width, and the center is made up of only concrete, with only a thin waterproof skin plate placed in the center.As a result, as the segment width increases, there are significant structural differences between the ends and the center, making it difficult to maintain uniformity as a structural material.

[0012] Furthermore, in the past, emphasis was placed on the functioning of the composite structure against the cross-sectional forces in the circumferential direction of the tunnel, but not much importance was placed on the composite structure in the axial direction of the tunnel.

[0013] For this reason, even though wide segments in the axial direction of the tunnel have become widely used, there has been a problem that they do not function as a composite structure against the cross-sectional forces in the axial direction of the tunnel.

[0014] Furthermore, in the case of the composite segment of Patent Document 1, the skin plate and the fill concrete can be integrated on the ground side of the tunnel by multiple shear stoppers protruding from the inner surface of the skin plate, but the integration of the fill concrete on the inner space side with the main reinforcement and distribution reinforcement in the fill concrete is impaired because the main reinforcement and distribution reinforcement are arranged in a lattice (mesh) pattern and multiple width stop reinforcements are also arranged, and so it is estimated that the function of the composite structure against cross-sectional forces in the axial and circumferential directions of the tunnel cannot be expected to be very good.

[0015] Furthermore, in the case of the composite segments of Patent Document 3 and Non-Patent Document 1, the segments are wide in the axial direction of the tunnel, so there is a risk that the skin plate and the fill concrete will not be integrated. For this reason, it is presumed that the functionality of the composite structure against cross-sectional forces in the axial direction of the tunnel cannot be expected to be very good.

[0016] The present invention has been made to solve the above problems, and aims to provide a composite segment that is wide in the axial direction of the tunnel by configuring the entire axial direction of the tunnel (segment width direction) to be a composite structure that functions not only against the cross-sectional forces in the circumferential direction of the shield tunnel but also against the cross-sectional forces in the axial direction of the tunnel. [Means for solving the problem]

[0017] The present invention provides a composite segment that is configured in a generally arc-shaped manner in side view along the natural ground of the tunnel, comprising a pair of main girders (side girders) arranged circumferentially around the tunnel, a pair of joint plates arranged between the ends of the main girders, a plurality of vertical ribs arranged between the main girders, a steel shell consisting of a skin plate arranged on the outer surface of a lattice frame formed by the main girders, the joint plates and the vertical ribs, and filler concrete filled into the steel shell, wherein the composite segment is characterized in that a plurality of shear stoppers are provided on the inner surface of the skin plate, a pair of reinforcing flanges are symmetrically attached to opposite sides of the main girders, and the filler concrete is unreinforced.

[0018] In particular, on the ground side of the composite segment, the fill concrete filled within the steel shell is integrally restrained within the steel shell by multiple shear stoppers provided on the inner surface of the skin plate, and the fill concrete on the inner space side is integrally restrained within the steel shell by a pair of reinforcing flanges attached to the opposing surfaces of the main girder.This increases the unity between the steel shell and the fill concrete, so that even a composite segment that is wide in the width direction of the segment (axial direction of the tunnel) can reliably function as a composite structure against cross-sectional forces in the axial direction of the tunnel.

[0019] As the slip stopper, in addition to stud dowels, headed studs, perforated steel plate dowels, shaped steel dowels or the like may be welded in large numbers to the inside surface of the skin plate 8.

[0020] It is also preferable to arrange spalling prevention reinforcement in the filled concrete to prevent the concrete from spalling. As the spalling prevention reinforcement, for example, a lattice reinforcing bar made of round steel or deformed steel bars is preferable.

[0021] Furthermore, a covering concrete may be filled in the surface layer of the filling concrete, and spalling prevention reinforcement may be arranged in the covering concrete.

[0022] The main girder, joint plate, longitudinal rib and / or the reinforcing flange can be formed from steel plate or steel section, etc. The reinforcing flange may also be formed integrally with the main girder.

[0023] Furthermore, by attaching reinforcing ribs to the longitudinal ribs to supplement the amount of steel in the center of the segment and increasing the cross-sectional rigidity in the tunnel axis direction, it is possible to form a composite segment that is even wider in the tunnel axis direction. [Effects of the Invention]

[0024] The present invention particularly comprises a pair of main girders arranged circumferentially around the tunnel, a plurality of vertical ribs arranged between the main girders, a pair of reinforcing flanges arranged symmetrically on opposite sides of the main girders, and reinforcing ribs arranged on the vertical ribs, and in particular, on the ground side of the composite segment, the fill concrete filled in the steel shell is integrally restrained within the steel shell by a plurality of shear stoppers provided on the inner surface of the skin plate, and the fill concrete on the inner space side is integrally restrained within the steel shell by a pair of reinforcing flanges attached to the opposite side of the main girders, thereby increasing the unity between the steel shell and the fill concrete, and even if the composite segment is wide in the width direction of the segment (axial direction of the tunnel), it can reliably function as a composite structure against the cross-sectional forces in the axial direction of the tunnel, thereby providing the effect of being able to provide a composite segment that is wide in the axial direction of the tunnel. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view of the exterior side of one embodiment of a composite segment of the present invention. FIG. [Figure 2] It is a perspective view of the inner surface side of the composite segment shown in FIG. 1. [Figure 3] Figures (a) and (b) are longitudinal cross-sectional views of the composite segment shown in FIGS. 1 and 2. [Figure 4] Figures (a) and (b) are cross-sectional views showing modified examples of the longitudinal ribs. [Figure 5] Figures (a) and (b) are cross-sectional views showing modified examples of the longitudinal ribs.

Embodiments for Carrying Out the Invention

[0026] Figs. 1-5 illustrate an embodiment of a five-sided steel shell composite segment composed of a steel shell and concrete according to the present invention.

[0027] Reference numeral 1 denotes a steel shell formed in a substantially arc shape in side view along the ground of the tunnel, 2 denotes the filled concrete in the steel shell 1, and reference numeral 3 denotes the covering concrete filled in the surface layer portion of the filled concrete 2.

[0028] The steel shell 1 includes a lattice-shaped frame body 7 formed in a longitudinal lattice frame shape that is long in the circumferential direction of the tunnel from a pair of main girders (side plates) 4, 4 arranged in the circumferential direction and axial direction of the tunnel, a pair of joint plates 5, 5, and a plurality of longitudinal ribs 6,... The steel shell is formed in a substantially arc shape in side view along the ground of the tunnel.

[0029] The joint plates 5, 5 are respectively welded to both ends in the circumferential direction of the tunnel of the main girders 4, 4, the longitudinal ribs 6,... are welded to the opposing side surfaces of the main girders 4, 4, and further, the skin plate 8 is welded to the outer surface of the lattice-shaped frame body 7, that is, the ground-side edge ends of the pair of main girders and the joint plates 5, 5.

[0030] Also, the main girders 4, the joint plates 5, and the longitudinal ribs 6 are formed from steel plates or section steels. In particular, the main girders 4, 4 are continuously formed in a substantially arc shape in side view in the circumferential direction of the tunnel along the inner peripheral surface of the tunnel.

[0031] The main girders 4, joint plates 5, and longitudinal ribs 6 are reinforced with reinforcing members (not shown) made of steel plates or structural steel, etc., as necessary. In this case, the reinforcing members may be attached to the outer and / or inner surfaces of the main girders 4, joint plates 5, and longitudinal ribs 6, respectively, or may be attached vertically in the form of ribs to the inner surfaces of the main girders 4 and joint plates 5 and both sides of the longitudinal ribs 6.

[0032] Furthermore, reinforcing ribs 9 are attached to the sides or tips of each of the longitudinal ribs 6. The reinforcing ribs 9 are formed continuously in the axial direction of the tunnel from steel plates or structural steel, and are welded to one side (see Figure 4(b)), both sides (see Figure 5(a)) or the tips (see Figure 5(b)) of the longitudinal ribs 6. The reinforcing ribs 9 may also be attached in multiple stages.

[0033] Additionally, numerous shear stoppers (hereinafter referred to as "stud dowels") 10 are provided protruding at predetermined intervals in the circumferential and axial directions of the tunnel on the inner surface of the skin plate 8. In addition to the stud dowels 10, headed studs, perforated steel plate dowels, shaped steel dowels, etc. are welded to the inner surface of the skin plate 8 as shear stoppers.

[0034] In addition, a pair of reinforcing flanges (hereinafter referred to as "inner flanges") 11, 11 are attached to the inner surfaces of the main girders 4, 4, facing each other. The inner flanges 11, 11 are made of steel plates or structural steel, and are formed continuously in a roughly arc-shaped form in a side view in the circumferential direction of the tunnel, following the arc-shaped form of the main girders 4, 4, and are welded to the inner surfaces of the main girders 4, 4.

[0035] The inner flanges 11, 11 may be attached in multiple stages (for example, two stages) in the circumferential direction of the tunnel depending on the height (width) of the main girders 4, 4. Also, the inner flanges 11, 11 may be formed integrally with the main girders 4, 4, respectively.

[0036] These vertical ribs 6, . . . , reinforcing ribs 9, stud dowels 10 and inner flanges 11 are completely embedded in the fill concrete 2 and are integrated with the fill concrete 2.

[0037] In particular, on the ground side, the fill concrete 2 filled inside the steel shell 1 is restrained integrally with the steel shell 1 by a number of stud dowels 10 protruding from the inner surface of the skin plate 8, and the fill concrete 2 on the inner space side is restrained integrally within the steel shell 1 by a pair of inner flanges 11, 11 attached to the opposing faces of the main girders 4, 4. This increases the unity between the steel shell 1 and the fill concrete 2, and allows even a composite segment that is wide in the width direction of the segment (axial direction of the tunnel) to function reliably as a composite structure against cross-sectional forces in the axial direction of the tunnel.

[0038] The inside of the core concrete 2 is an unreinforced structure with no particular reinforcing bars arranged inside, and the surface of the core concrete 2 is filled with a certain thickness of covering concrete 3, and anti-slip bars 12 are arranged inside the covering concrete 3 to prevent the core concrete 2 from spalling (see Figure 3(a)).

[0039] The covering concrete 3 may be omitted, and anti-slip reinforcement bars 12 may be arranged in the surface layer of the filling concrete 2 (see FIG. 3(b)).

[0040] Further, reference numeral 13 denotes an inter-segment joint that joins adjacent composite segments in the circumferential direction of the tunnel, and the inter-segment joint 13 is attached to the joint plate 5.

[0041] Reference numeral 14 denotes an inter-ring joint that joins adjacent segment rings in the axial direction of the tunnel, and the inter-ring joint 14 is attached to the main girder 4. [Industrial Applicability]

[0042] The present invention makes it possible to provide a composite segment that is wide in the direction of the tunnel axis by configuring the segment so that the entire width direction is a composite structure and functions as a composite structure not only against cross-sectional forces in the direction of the tunnel circumference but also against cross-sectional forces in the direction of the tunnel axis. [Explanation of symbols]

[0043] 1 steel shell 2. Filling concrete 3. Coated concrete 4 Main digit 5 Joint plate 6 Vertical ribs 7 Lattice frame 8 Skin Plate 9 Reinforcing ribs 10 Stud dowel (slip prevention) 11 Inner flange (reinforced flange) 12 Anti-slip reinforcement 13 Inter-segment joints 14 Ring-to-ring joint

Claims

1. a composite segment formed in a generally arc-shaped configuration in a side view along the ground of the shield tunnel, comprising a pair of main girders arranged in the circumferential direction of the shield tunnel, a pair of joint plates respectively arranged between the ends of the main girders, a plurality of vertical ribs arranged between the main girders, a steel shell consisting of skin plates arranged on the outer surfaces of a lattice frame formed by the main girders, the joint plates and the vertical ribs, and fill concrete filled into the steel shell, wherein the composite segment is characterized in that the skin plate is arranged across the entire width, no flange is provided on the inside of the skin plate facing the ground, a plurality of shear stoppers are provided on the inner surface of the skin plate, reinforcing flanges are attached symmetrically to opposite sides of the main girders, and the fill concrete is unreinforced.

2. 2. The composite segment according to claim 1, wherein spalling prevention reinforcement is arranged within the filled concrete.

3. 2. A composite segment according to claim 1, wherein a surface layer of said filling concrete is filled with covering concrete, and spalling prevention reinforcement is arranged within said covering concrete.

4. 2. A composite segment according to claim 1, wherein said longitudinal ribs are attached with reinforcing ribs.

5. 3. A composite segment according to claim 2, wherein a reinforcing rib is attached to said longitudinal rib.

6. 4. A composite segment according to claim 3, wherein a reinforcing rib is attached to said longitudinal rib.

7. 7. The composite segment according to claim 1, wherein the main girder, joint plates, longitudinal ribs and / or reinforcing flanges are formed from steel plates or structural steel.

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