segment

Abstract

The present invention provides a segment that can increase bending rigidity and can be manufactured without causing deformation of the main girder due to the heat of welding. [Solution] By providing a reinforcing member 14 that extends in an arc shape along the circumferential direction of the tunnel within the steel shell formed by each main girder 11, skin plate 12, and joint plate 13, the strength against bending load can be ensured not only by each main girder 11 but also by the reinforcing member 14, and the bending rigidity of the segment 10 can be significantly increased. In this case, the outer flange 14a and inner flange 14b of the reinforcing member 14 are arranged in a non-joined state to the main girder 11, so it can be manufactured without causing distortion or deformation of the main girder due to the heat when welding flange members to increase bending rigidity as in the conventional method, and accurate external dimensions can always be ensured.

Description

Technical Field

[0001] The present invention relates to segments used, for example, in the lining of shield tunnels.

Background Art

[0002] Conventionally, in the construction of shield tunnels, a plurality of segments formed in an arc shape along the tunnel circumferential direction are joined in a ring shape in the tunnel circumferential direction, and the segments joined in a ring shape are joined in the tunnel axial direction to form a lining. As segments used in this method, a pair of main girders respectively arranged on both end faces in the tunnel axial direction of the segment, an arc-shaped skin plate arranged on the outer peripheral surface of the segment, and a pair of joint plates respectively arranged on both end faces in the tunnel circumferential direction of the segment are provided. Reinforcing bars and rib steel materials are provided in a steel shell made of these steel materials, and by placing in-place concrete, an integrated structure of the steel shell and the concrete is known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, in the conventional segment described above, flange members made of steel are joined to both ends of the main girder in the height direction in order to increase the bending rigidity against the high internal pressure and loads acting in the radial direction of the tunnel. However, since the flange members are welded along the entire length of the main girder in the circumferential direction of the tunnel, there was a problem that the heat from welding caused distortion and deformation in the main girder, reducing dimensional accuracy. In such cases, in order to ensure dimensional accuracy, the main girder that has been distorted or deformed must be corrected, which presents a problem as it requires a great deal of time and cost for this work.

[0005] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a segment that can increase bending rigidity and can be manufactured without causing deformation of the main girder due to welding heat. [Means for solving the problem]

[0006] To achieve the above objective, the present invention provides a segment comprising a pair of arc-shaped main girders arranged on both end faces in the tunnel axial direction of the segment, an arc-shaped skin plate arranged on the outer circumferential surface of the segment, and a pair of joint plates arranged on both end faces in the tunnel circumferential direction of the segment, wherein a segment is formed by pouring infill concrete into a steel shell formed by each of the main girders, skin plate and joint plate, and a reinforcing member extending in an arc shape along the tunnel circumferential direction is provided within the steel shell, the reinforcing member is formed from an outer flange arranged on the outer circumferential surface side of the segment, an inner flange arranged on the inner circumferential surface side of the segment, and a web connecting the outer flange and the inner flange, and the outer flange and the inner flange are arranged in a non-joined state to the main girders.

[0007] As a result, reinforcing members extending in an arc shape along the circumferential direction of the tunnel are provided within the steel shell, ensuring strength against bending loads not only from the main girder but also from the reinforcing members. In this case, since the outer and inner flanges of the reinforcing members are positioned without being joined to the main girder, distortion and deformation of the main girder due to heat generated when welding flange members to increase bending rigidity, as in conventional designs, is avoided. [Effects of the Invention]

[0008] According to the present invention, since the strength against bending loads can be ensured not only by the main girder but also by the reinforcing members, the bending rigidity of the segment can be significantly increased. In this case, it is possible to manufacture without causing distortion or deformation of the main girder due to the heat generated when welding the flange members to increase bending rigidity, as in the conventional method, so that accurate external dimensions can always be ensured. As a result, welding work can be reduced, and manufacturing costs can be reduced without the need for corrective work on the main girder that has been distorted or deformed, as in the conventional method. [Brief explanation of the drawing]

[0009] [Figure 1] Front view of a segment showing one embodiment of the present invention [Figure 2] Bottom view of a segment with the infill concrete omitted. [Figure 3] Side cross-sectional view of the segment [Figure 4] Cross-sectional view in the direction of arrow AA [Figure 5] Enlarged perspective view of the main part of a segment with the infill concrete omitted. [Figure 6] Enlarged perspective view of the main part of a segment with the infill concrete omitted. [Modes for carrying out the invention]

[0010] Figures 1 to 6 show one embodiment of the present invention, illustrating segments used for lining a shield tunnel.

[0011] The segment 10 of this embodiment comprises a pair of main girders 11 arranged on both ends of the tunnel in the axial direction, an arc-shaped skin plate 12 arranged on the outer circumferential surface of the segment 10, and a pair of joint plates 13 arranged on both ends of the segment 10 in the circumferential direction of the tunnel. A pair of reinforcing members 14 and a plurality of longitudinal ribs 15 are arranged within the steel shell formed by each main girder 11, the skin plate 12, and each joint plate 13, and a filling concrete 16 is poured into this steel shell, integrating the steel shell and the filling concrete 16.

[0012] Each main girder 11 is made of plate-shaped steel material that is spaced apart from each other in the direction of the tunnel axis, and is formed to form an arc shape along the circumferential direction of the tunnel.

[0013] The skin plate 12 is made of a thin steel plate, and both ends in the width direction (tunnel axis direction) are welded to the outer edges of each main girder 11.

[0014] Each joint plate 13 is made of a horizontally elongated, flat steel material, with both ends in the longitudinal direction (tunnel axis direction) welded to the ends of each main girder 11, and one end in the short direction (tunnel radial direction) welded to the end of the skin plate 12.

[0015] The reinforcing member 14 consists of an outer flange 14a positioned on the outer circumferential surface side of the segment 10, an inner flange 14b positioned on the inner circumferential surface side of the segment, and a web 14c connecting the outer flange 14a and the inner flange 14b, and is formed to extend in an arc shape along the circumferential direction of the tunnel. The outer flange 14a is positioned close to the outer circumference of the segment 10, and its outer circumferential surface is formed to have the same curvature as the inner circumferential surface of the skin plate 12, and is positioned to be in surface contact with the inner circumferential surface of the skin plate 12 in a non-jointed state. The inner flange 14b is positioned close to the inner circumference of the segment 10, and its inner circumferential surface is formed to have the same curvature as the inner edge of the main girder 11 in the tunnel radial direction, and is positioned at a slight distance in the tunnel radial direction from the inner circumferential surface of the infill concrete 16.

[0016] Each longitudinal rib 15 is made of a flat steel material and is arranged at intervals in the tunnel circumferential direction so that the thickness direction is the tunnel circumferential direction. One end of the longitudinal rib 15 in the tunnel axis direction is welded to the inner surface of the main girder 11, and the other end in the tunnel axis direction is welded to the web 14c of the reinforcing member 14. Also, the upper end of the longitudinal rib 15 is arranged with a slight interval from the outer flange 14a of the reinforcing member 14.

[0017] The filling concrete 16 is placed in the steel shell at a factory or the like, and its inner peripheral surface is formed in an arc shape along the tunnel circumferential direction. In this case, the inner peripheral side of the filling concrete 16 is formed so as to protrude slightly radially inward of the tunnel diameter from the inner peripheral ends of the respective main girders 11.

[0018] Also, as a joint for joining the segments 10 to each other in the tunnel circumferential direction, the segment 10 includes a first male joint 17 provided on one of the widthwise one end side and the other end side of each joint plate 13, and a first female joint 18 provided on the other of the widthwise one end side and the other end side of the joint plate 13. The first male joint 17 and the first female joint 18 are arranged on opposite sides in the width direction of the joint plate 13 at the joint plate 13 on one end side and the joint plate 13 on the other end side in the tunnel axis direction of the segment 10. The first male joint 17 and the first female joint 18 are composed of well-known joints for joining the segments in the tunnel circumferential direction, and are respectively connected to anchor bars (not shown) embedded in the filling concrete 16.

[0019] Furthermore, as a joint for joining the segments 10 to each other in the tunnel axis direction, the segment 10 includes a second male joint 19 provided on one main girder 11 and a second female joint 20 provided on the other main girder 11. The second male joint 19 and the second female joint 20 are provided at intervals from each other at a plurality of locations in the tunnel circumferential direction. Also, the second male joint 19 and the second female joint 20 are constituted by well-known joints for joining the segments in the tunnel axis direction.

[0020] In the segment 10 configured as described above, when joining the segments 10 to each other in the tunnel circumferential direction, while moving one segment 10 relative to the other segment 10 in the tunnel axis direction, the first male joint 17 and the first female joint 18 of the joint plate 13 are engaged. As a result, although not shown, a plurality of segments 10 are joined in a ring shape.

[0021] Further, when joining the segments 10 joined in a ring shape in the tunnel axis direction, the second male joint 19 and the second female joint 20 of the main girder 11 are coupled by abutting the segments 10 in the tunnel axis direction.

[0022] In the segment 10 joined in the tunnel axis direction, when receiving a load in the tunnel radial direction, the strength against bending load is ensured not only by each main girder 11 but also by the reinforcing member 14. At that time, since the outer flange 14a disposed on the outer peripheral surface side of the segment 10 of the reinforcing member 14 is disposed at a position where it is in surface contact with the inner peripheral surface of the skin plate 12, the distance from the neutral axis of the bending stress to the outer flange 14a becomes maximum.

[0023] Also, when a tensile force in the tunnel axis direction is generated in the segment 10, the tensile force is applied to the second male and female joints 19, 20 of each segment 10 and is transmitted to the reinforcing member 14 through each vertical rib 15. As a result, the portions where the tensile force from the second male and female joints 19, 20 in the main girder 11 is applied are reinforced by each vertical rib 15 and the reinforcing member 14. Further, by each vertical rib 15 disposed between the main girder 11 and the reinforcing member 14, the integrality between the main girder 11, the reinforcing member 14, and the filling concrete 16 is enhanced by the adhesion force between each vertical rib 15 and the surrounding concrete.

[0024] As described above, according to the present embodiment, since the reinforcing member 14 extending in an arc shape along the tunnel circumferential direction is provided in the steel shell formed by each main girder 11, the skin plate 12, and each joint plate 13, the strength against bending load can be ensured not only by each main girder 11 but also by the reinforcing member 14, and the bending rigidity of the segment 10 can be significantly increased.

[0025] In this case, the reinforcing member 14 is formed from an outer flange 14a positioned on the outer circumferential surface side of the segment 10, an inner flange 14b positioned on the inner circumferential surface side of the segment 10, and a web 14c connecting the outer flange 14a and the inner flange 14b. Furthermore, since the outer flange 14a and the inner flange 14b are positioned in a non-joined state to the main girder 11, it is possible to manufacture the reinforcing member without causing distortion or deformation of the main girder due to the heat generated when welding flange members to increase bending rigidity, as in the conventional method, and accurate external dimensions can always be ensured. This reduces welding work and eliminates the need for corrective work on the main girder that has been distorted or deformed, as in the conventional method, thereby reducing manufacturing costs.

[0026] Furthermore, since the outer flange 14a of the reinforcing member 14 is positioned close to the inner circumferential surface of the skin plate 12, the distance from the neutral axis of bending stress to the outer flange 14a can be maximized, which is extremely advantageous in increasing the bending rigidity of the segment 10 by the reinforcing member 14. In this case, since the outer flange 14a is in surface contact with the inner circumferential surface of the skin plate 12 in a non-joined state, there is no need for strict dimensional accuracy as in the case of joining by welding, and there is also the advantage that the heat of welding does not cause distortion or deformation in the skin plate 12.

[0027] Furthermore, the main girder 11 is provided with a plurality of ribs 15 arranged on the inside of the main girder 11 at intervals from each other in the circumferential direction of the tunnel, with both ends joined to the main girder 11 and the reinforcing member 14. Second male joints 19 and second female joints 20, which join the segments 10 together in the axial direction of the tunnel, are provided on the main girder 11 so as to be located between the ribs 15. As a result, the parts of the main girder 11 to which tensile forces from the second male and female joints 19 and 20 are applied can be reinforced by each longitudinal rib 15 and the reinforcing member 14. Moreover, without providing dedicated members such as dowels, the adhesion force between each longitudinal rib 15 and the surrounding concrete can enhance the unity between the main girder 11, the reinforcing member 14 and the infill concrete 16, thereby simplifying the structure while ensuring high rigidity.

[0028] Furthermore, the above-described embodiment is just one example of the present invention, and the present invention is not limited to what is described in the above-described embodiment. [Explanation of Symbols]

[0029] 10...Segment, 11...Main girder, 12...Skin plate, 13...Joint plate, 14...Reinforcement member, 14a...Outer flange, 14b...Inner flange, 14c...Web, 15...Longitudinal rib, 16...Infill concrete, 19...Second male joint, 20...Second female joint.

Claims

1. A segment is formed by pouring concrete into a steel shell formed by each of the main girders, skin plates, and joint plates, with each of the main girders, skin plates, and joint plates positioned on both ends of the segment in the axial direction of the tunnel, respectively. A reinforcing member extending in an arc shape along the circumferential direction of the tunnel is provided within the steel shell. The reinforcing member is formed from an outer flange positioned on the outer circumferential surface side of the segment, an inner flange positioned on the inner circumferential surface side of the segment, and a web connecting the outer flange and the inner flange, and the outer flange and the inner flange are positioned in a non-joined state to the main girder. A segment characterized by the following features.

2. The outer flange is positioned close to the outer circumference of the segment, and the inner flange is positioned close to the inner circumference of the segment. The segment joining structure according to claim 1.

3. The outer flange is positioned so as to be in non-joint surface contact with the inner circumferential surface of the skin plate. The segment joining structure according to feature 2.

4. The main girder is provided with a plurality of longitudinal ribs arranged on the inside of the main girder at intervals in the circumferential direction of the tunnel, with both ends joined to the main girder and reinforcing members, Joints that connect segments in the tunnel axis direction were installed on the main girder so that they were located between the longitudinal ribs. The segment joining structure according to claim 1.

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