Segment connector and segment connection method

Abstract

To provide a segment connector capable of preventing a pair of segments from moving relative to one another in the axial direction of a tunnel, while simplifying a connection structure of the pair of segments and suppressing a decrease in the strength of each segment.SOLUTION: A segment connector 1 includes an axial movement restricting portion 30 that restricts the relative movement of a pair of segments connected by an engagement of a male joint 10 and a female joint 20 in a direction opposite to the direction of engagement. The axial movement restricting portion 30 has a circumferential moving portion 31 and a contacted portion 41. The circumferential moving portion 31 is located on the female joint 20 at a position that always overlaps with the female joint 20 when viewed in the axial direction, and is provided so as to be movable in the circumferential direction while movement in the thickness direction and axial direction of the segments is restricted. The contacted portion 41 is located on the male joint 10 at a position that overlaps with the circumferential moving portion 31 that has moved in the circumferential direction when the male joint 10 and the female joint 20 are engaged with each other when viewed in the axial direction.SELECTED DRAWING: Figure 6C

Description

Technical Field

[0001] The present invention relates to a segment connector for connecting a plurality of segments arranged on an excavation face in the circumferential direction and a method for connecting the segments when forming a tunnel by the shield method.

Background Art

[0002] In the shield method, a ring-shaped segment ring is assembled by connecting a plurality of arc-shaped segments in the circumferential direction. When assembling the segment ring, it is known that the K segment, which is the last to be connected, is likely to come out in the axial direction of the tunnel after connection. Therefore, for example, in Patent Document 1 and Patent Document 2, a configuration for restricting the relative movement of the K segment and the B segment to which the K segment is connected is disclosed after connecting the K segment and the B segment.

[0003] In the joint structure disclosed in Patent Document 1, a locking member is provided between two-piece one-pass joints that connect the K segment and the B segment. The locking member is composed of a spring member housed in a groove formed in one of the K segment and the B segment, and a wedge member urged by the spring member toward the other of the K segment and the B segment. When the wedge member engages with a groove formed in the other of the K segment and the B segment, the K segment is prevented from moving in a direction opposite to the direction in which it fits into the B segment.

[0004] Further, the connector disclosed in Patent Document 2 includes a male joint provided on one of adjacent segments and having a tapered portion, a female joint provided on the other of adjacent segments and having a fitting portion that fits with the tapered portion, and a restricting portion that engages with the male joint in a state where the tapered portion and the fitting portion are fitted to restrict the slide of the male joint.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 6355391 [Patent Document 2] Patent No. 7118026 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The joint structure disclosed in Patent Document 1 has a locking member separate from the joint that connects the K segment and the B segment. That is, the joint structure has the locking member separate from the joint at one end of the K segment and the B segment, and has a groove separate from the joint at the other end of the K segment and the B segment into which the wedge-shaped member of the locking member is inserted. Consequently, the joint structure makes the structure of the segment ends complex, and the groove formed in the segment may reduce the strength of the segment.

[0007] Furthermore, the restricting portion of Patent Document 2 is configured such that a restricting pin that moves in the thickness direction of the segment engages with the side surface of the male joint, thereby restricting the sliding of the male joint. Therefore, the segment having the connector of Patent Document 2 has a thickness that allows the restricting pin to move in the thickness direction within its interior. In addition, the segment having the connector of Patent Document 2 has a hole that extends in the thickness direction and serves as a movement passage for the restricting pin. Consequently, in the configuration of Patent Document 2, the thickness dimension of the segment increases, and the strength of the segment may decrease due to the hole.

[0008] In contrast, there is a need for a segment connector that connects a pair of segments in the circumferential direction, which can prevent the pair of segments from moving relative to each other in the opposite direction to the direction in which they fit together, while simplifying the connection structure of the pair of segments and suppressing a decrease in the strength of each segment.

[0009] The object of the present invention is to provide a segment connector for circumferentially connecting a pair of segments that prevents relative movement of the pair of segments in the opposite direction to the direction in which they fit together, while simplifying the connection structure of the pair of segments and suppressing a decrease in the strength of each segment. [Means for solving the problem]

[0010] A segment connector according to one embodiment of the present invention comprises a pair of segments having a predetermined thickness and arranged circumferentially on the excavated surface of a tunnel, a male joint provided at the circumferential end of one segment, and a female joint provided at the circumferential end of the other segment of the pair of segments that is opposite to the circumferential end of the one segment, wherein the male joint and the female joint are configured to fit together when the pair of segments move relative to each other in the axial direction of the tunnel, and the fitting of the male joint and the female joint connects the pair of segments circumferentially. This segment connector includes an axial movement restricting part that restricts the relative movement of the pair of segments in the opposite direction to the fitting direction. The axial movement restricting portion includes a circumferential movement portion provided on one of the male joint or the female joint, which is positioned to always overlap with one of the male joint or the female joint when the male joint and the female joint are viewed in the axial direction, and which is capable of moving in the circumferential direction while restricting the movement of the segment in the thickness direction and the axial direction; and a contacted portion provided on the other of the male joint or the female joint, which is positioned to overlap with the circumferential movement portion when the male joint and the female joint are fitted together and have moved in the circumferential direction when the male joint and the female joint are viewed in the axial direction (first configuration).

[0011] As a result, the segment connector that connects a pair of segments aligned in the circumferential direction of the tunnel has an axial movement restricting portion that restricts relative movement of the pair of segments in the opposite direction to the direction in which they fit together. Therefore, since there is no need to provide the axial movement restricting portion separately from the segment connector, the configuration and connection structure of the pair of segments can be simplified, and a reduction in the strength of the pair of segments can be suppressed. Moreover, in the axial movement restricting portion, the circumferential movement portion moves in the circumferential direction while restricting movement in the thickness direction and the axial direction of the segment, and contacts the contacted portion. Therefore, compared to a configuration in which the movement portion moves in the thickness direction of the segment (the radial direction of the tunnel), the thickness of each segment can be made more compact, while suppressing a reduction in the strength of each segment in the thickness direction.

[0012] Therefore, in a segment connector that connects a pair of segments in the circumferential direction, it is possible to realize a configuration that prevents the pair of segments from moving relative to each other in the axial direction of the tunnel, while simplifying the connection structure of the pair of segments and suppressing a decrease in the strength of each segment.

[0013] In the first configuration described above, the circumferentially movable portion is provided on either the male or female joint so as to be located at the axial end of the segment connector (second configuration).

[0014] The circumferentially movable portion located at the axial end of the segment connector more reliably prevents a pair of circumferentially aligned segments from moving in the opposite direction to the direction in which they fit together.

[0015] In the second configuration described above, the male joint and the female joint are configured to fit together by the relative axial movement of the pair of segments. The circumferential moving portion is provided on either the male joint or the female joint so as to be located at the rear end of the male joint in the direction of movement relative to the female joint in the segment connector (third configuration).

[0016] In a segment connector, a circumferentially movable portion located at the rear end of the male connector in the direction of movement relative to the female connector can more reliably prevent a pair of circumferentially aligned segments from moving relative to each other in the opposite direction to the direction in which they fit together and coming apart.

[0017] In the first configuration described above, the axial movement restricting portion is provided on the other of the male or female joint and further includes a circumferential positioning portion that, when the male and female joints are viewed in the axial direction, positions the circumferentially moving portion, which has moved in the circumferential direction while the male and female joints are fitted together, at a circumferential position that overlaps with the contacted portion (fourth configuration).

[0018] This allows the male and female joints to be positioned so that the circumferentially moving portion overlaps with the contacted portion when viewed in the axial direction. Therefore, the circumferentially moving portion and the contacted portion can more reliably prevent the pair of segments from moving relative to each other in the opposite direction to the direction in which they are fitted together.

[0019] In the first configuration described above, the male joint and the female joint are configured to be fitted together by the relative axial movement of the pair of segments. The contacted portion is provided on the male joint. The circumferentially moving portion has a moving portion body provided on the female joint such that when the male joint contacts the front end in the direction of movement, the rear end in the direction of movement moves circumferentially and approaches the male joint, and a head protruding circumferentially from the rear end of the moving portion body such that, when the male joint and the female joint are viewed in the axial direction and the male joint and the female joint are fitted together, the rear end of the moving portion body moves circumferentially and overlaps with the contacted portion (fifth configuration).

[0020] Even with an axial movement restricting section having such a configuration, it is possible to prevent a pair of segments arranged in the circumferential direction from moving relative to each other in the axial direction. That is, when the male joint comes into contact with the front end of the moving section body in the direction of movement, the rear end in the direction of movement moves circumferentially and approaches the male joint. Thus, when the male joint and the female joint are fitted together, the rear end of the moving section body approaches the male joint.

[0021] And at the rear end portion, a head protruding in the circumferential direction is provided so as to overlap the contact portion provided on the male joint when the male joint and the female joint are viewed in the axial direction. By the head, it is possible to prevent relative movement in the direction opposite to the direction in which a pair of segments arranged in the circumferential direction are fitted. Therefore, with a simple configuration, an axial movement restricting portion can be provided in the segment connector.

[0022] In the first configuration, the circumferential movement portion includes a movement restricting portion and an elastic support portion that elastically supports the movement restricting portion with respect to one of the male joint or the female joint. The contact portion has a recess provided in the other of the male joint or the female joint so that a part of the movement restricting portion can be inserted in a state where the male joint and the female joint are fitted (sixth configuration).

[0023] Also, with the axial movement restricting portion having such a configuration, it is possible to prevent relative movement in the direction opposite to the direction in which a pair of segments arranged in the circumferential direction are fitted. That is, when the male joint and the female joint are fitted, a part of the movement restricting portion elastically supported by the elastic support portion with respect to one of the male joint or the female joint is inserted into a recess provided in the other of the male joint or the female joint. Thereby, relative movement in the direction opposite to the fitting direction of the pair of segments is prevented by the movement restricting portion.

[0024] In the first configuration, the circumferential movement portion and the other joint of the male joint or the female joint are configured to contact when the pair of segments move relative to each other in the fitting direction. At least one of the circumferential movement portion and the other joint has an inclined surface extending in a direction inclined with respect to the fitting direction at a portion where the circumferential movement portion and the other joint contact when moving relative to each other in the fitting direction (seventh configuration).

[0025] 8] In this configuration, when the pair of segments move relative to each other in the fitting direction, the circumferential movement portion contacts the male joint or the female joint. At least one of the circumferential movement portion and the male joint or the female joint has an inclined surface at the contacting portion. The inclined surface extends in a direction inclined with respect to the fitting direction. Therefore, when the male joint moves in the fitting direction with respect to the female joint, one of the male joint or the female joint contacts the inclined surface of the circumferential movement portion. As a result, the circumferential movement portion can be moved to a position where it does not overlap with one of the male joint and the female joint when viewed in the axial direction of the male joint and the female joint. Thereby, it is possible to prevent the fitting of the male joint and the female joint from being obstructed.

[0026] A segment connection method according to an embodiment of the present invention is a segment connection method for connecting a pair of segments arranged in the circumferential direction of a tunnel by a segment connector having a male joint and a female joint. This segment connection method includes a temporary fixing step of temporarily fixing the circumferential movement portion of the segment connector having any one of the first to sixth configurations to a predetermined position in the circumferential direction of the tunnel by a temporary fixing portion, a segment assembling step of relatively moving the pair of segments in the axial direction of the tunnel to relatively move the male joint and the female joint in the axial direction, and a segment movement restricting step of removing the temporary fixing portion by the relative movement of the male joint and the female joint in the axial direction and moving the circumferential movement portion in the circumferential direction to contact the contacted portion of the segment connector (first method).

[0027] Thereby, a pair of segments arranged in the circumferential direction of the tunnel can be connected by a segment connector, and it is possible to prevent the pair of segments from moving relative to each other in a direction opposite to the fitting direction by the circumferential movement portion and the contacted portion of the segment connector. Therefore, there is no need to provide a member for restricting the relative movement of the pair of segments separately from the segment connector. Therefore, the configuration and connection structure of the pair of segments can be simplified, and a decrease in the strength of the pair of segments can also be suppressed.

Effect of the Invention

[0028] A segment connector according to one embodiment of the present invention has an axial movement restricting portion having a circumferential movement portion provided on one of the male or female joints so as to be movable in the circumferential direction of the segment, and a contacted portion provided on the other of the male or female joint at a position that overlaps with the circumferential movement portion that has moved in the circumferential direction when viewed in the axial direction of the tunnel.

[0029] This makes it possible to provide a segment connector that connects a pair of segments in the circumferential direction, while preventing the pair of segments from moving relative to each other in the opposite direction to the direction in which they fit together, while simplifying the connection structure of the pair of segments and suppressing a decrease in the strength of each segment. [Brief explanation of the drawing]

[0030] [Figure 1] Figure 1 is a schematic diagram showing how segments are placed on the excavation surface of a tunnel. [Figure 2A] Figure 2A schematically shows how the K segment is positioned relative to the B segment. [Figure 2B] Figure 2B schematically shows how the K segment is positioned relative to the B segment. [Figure 3A] Figure 3A schematically shows K segments connected circumferentially by segment connectors. [Figure 3B] Figure 3B schematically shows K segments connected circumferentially by segment connectors. [Figure 4A] Figure 4A is a diagram showing the schematic configuration of the segment connector according to Embodiment 1. [Figure 4B] Figure 4B is a diagram showing the schematic configuration of the segment connector according to Embodiment 1. [Figure 5] Figure 5 is a diagram showing the schematic configuration of the circumferential moving part of the segment connector according to Embodiment 1. [Figure 6A]Figure 6A is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 1 are connected. [Figure 6B] Figure 6B is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 1 are connected. [Figure 6C] Figure 6C is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 1 are connected. [Figure 7] Figure 7 is a flowchart showing the process of the segment linking method. [Figure 8A] Figure 8A is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to a modified example 1 of Embodiment 1 are connected. [Figure 8B] Figure 8B is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Modification 1 of Embodiment 1 are connected. [Figure 8C] Figure 8C is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to a modified example 1 of Embodiment 1 are connected. [Figure 9A] Figure 9A is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of a segment connector according to a modified example 2 of Embodiment 1 are connected. [Figure 9B] Figure 9B is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to a modified example 2 of Embodiment 1 are connected. [Figure 9C] Figure 9C is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of a segment connector according to a modified example 2 of Embodiment 1 are connected. [Figure 10A] Figure 10A is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 2 are connected. [Figure 10B]Figure 10B is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 2 are connected. [Figure 10C] Figure 10C is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 2 are connected. [Figure 11] Figure 11 is a diagram showing the schematic configuration of the circumferential moving part of the segment connector according to Embodiment 2. [Figure 12A] Figure 12A is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 3 are connected. [Figure 12B] Figure 12B is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 3 are connected. [Figure 12C] Figure 12C is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 3 are connected. [Figure 12D] Figure 12D is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 3 are connected. [Figure 13A] Figure 13A is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 4 are connected. [Figure 13B] Figure 13B is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 4 are connected. [Figure 13C] Figure 13C is a diagram illustrating the operation of the axial movement restricting part when the male and female joints of the segment connector according to Embodiment 4 are connected. [Figure 14] Figure 14 shows an example of the shape of the front end of the male fitting portion and the shape of the circumferentially moving portion of a segment connector according to another embodiment. [Figure 15]Figure 15 shows an example of the shape of the temporary fastening portion of a segment connector according to another embodiment. [Modes for carrying out the invention]

[0031] The following describes each embodiment with reference to the drawings. In each drawing, the same parts are denoted by the same reference numerals, and the description of those parts will not be repeated. Note that the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components or the dimensional ratios of each component.

[0032] In the following description, the axial direction means the direction in which the tunnel extends. The circumferential direction means the direction in which the inner surface of the tunnel extends when viewed in the axial direction. The thickness direction means the thickness direction of the segments arranged on the excavated surface of the tunnel. Note that the circumferential direction includes not only the direction that coincides with the direction in which the inner surface of the tunnel extends when viewed in the axial direction, but also directions that are inclined at an angle of 45 degrees or less with respect to the direction in which the inner surface of the tunnel extends.

[0033] Furthermore, in the following explanation, the expressions "fix," "connect," and "attach" (hereinafter referred to as "fixing, etc.") include not only cases where components are directly fixed to each other, but also cases where they are fixed to each other via other components. In other words, in the following explanation, the expressions "fixing, etc." include both direct and indirect fixing of components to each other.

[0034] (Embodiment 1) The segment connector 1 according to this embodiment will be described with reference to Figures 1 to 7. The segment connector 1 is a connector that connects a pair of adjacent segments in the circumferential direction in a tunnel constructed by the shield tunneling method.

[0035] First, let me briefly explain the shield tunneling method. In the shield tunneling method, the ground on which the tunnel will be formed is excavated in a cylindrical shape using a shield machine, and multiple segments are lined up on the excavated surface formed by the excavation. Other segments are then connected to the already installed segments in the circumferential direction to assemble a cylindrical segment ring and form the tunnel.

[0036] The plurality of segments have a predetermined thickness and are arc-shaped when viewed in the axial direction of the tunnel. The plurality of segments are made of, for example, concrete, steel, or the like.

[0037] The aforementioned multiple segments include A segments, B segments, and K segments. Figure 1 schematically shows a segment ring composed of A segments, B segments, and K segments. In Figure 1, A segments are denoted by code A, B segments by code B, and K segments by code K.

[0038] Note that the shield machine, which is not shown in the figure, excavates the ground while moving in the excavation direction shown in Figure 1. Multiple segments are lined up and connected to each other on the excavated surface formed by the excavation of the shield machine, and the segment ring is assembled sequentially at the rear in the direction of excavation. The shield machine excavates the ground by moving in the direction of excavation while pushing the assembled segment ring with the jacks of the shield machine.

[0039] The A segment, the B segment, and the K segment have different shapes from each other. The A segment is rectangular in shape when viewed in the thickness direction, with both circumferential ends extending in the axial direction. The B segment is trapezoidal in shape when viewed in the thickness direction, with one circumferential end extending in the axial direction and the other circumferential end extending in a direction intersecting the axial direction. The K segment is trapezoidal in shape when viewed in the thickness direction, with both circumferential ends extending in a direction intersecting the axial direction.

[0040] For example, the segment ring shown in Figure 1 is assembled as follows. Note that Figure 1 shows an example where each segment ring has three A segments, but the number of A segments in a single segment ring varies depending on the diameter of the tunnel.

[0041] First, three A segments are connected in the circumferential direction. Next, B segments are connected to both circumferential ends of the three connected A segments. This causes the open ends of the two B segments to face each other, and a trapezoidal segment insertion space is formed between them. Finally, the K segment is moved from the inside to the outside of the tunnel at a position offset from the segment insertion space in the direction of tunnel excavation (see Figure 2A), and also moved in the opposite direction to the excavation direction in the axial direction of the tunnel, and inserted into the segment insertion space (see Figure 2B).

[0042] Note that in Figure 1, for illustrative purposes, the segment ring located furthest forward in the excavation direction is shown spaced apart from the other segment rings. However, when connecting segment B to segment A, segment A is connected axially to the existing segment ring. When connecting segment K to segment B, segment B is connected axially to the existing segment ring.

[0043] When the K segment is inserted into the space between the two B segments, it is connected to the B segments by the segment connector 1. That is, the K segment and the B segments are connected circumferentially by relative movement in the axial direction. The K segment is also connected to an existing segment ring located axially with respect to the space.

[0044] Figures 2A and 2B schematically show how a K segment is inserted between two B segments. Figures 3A and 3B schematically show the K segment and B segment connected circumferentially by the segment connector 1. Figures 2A and 3A show the segment viewed in the axial direction of the tunnel. Figures 2B and 3B show the segment viewed in the thickness direction. In Figures 2A and 2B, the white arrows indicate the direction of movement of the K segment.

[0045] As shown in Figures 2A to 3B, the segment connector 1 comprises a male connector 10 and a female connector 20. The male connector 10 is provided at the circumferential end of one of the adjacent K-segments and B-segments. The female connector 20 is provided at the circumferential end of the other adjacent K-segment and B-segment that faces the circumferential end of the first segment.

[0046] In this embodiment, each circumferential end of the K-segment is provided with one male joint 10 and one female joint 20. Specifically, at each circumferential end of the K-segment, the male joint 10 is provided on the front side in the excavation direction, and the female joint 20 is provided on the rear side in the excavation direction.

[0047] At both ends of the B segment in the circumferential direction, at the ends facing the ends of the K segment, a female joint 20 is provided in the portion facing the male joint 10 of the K segment. At both ends of the B segment in the circumferential direction, at the ends facing the ends of the K segment, a male joint 10 is provided in the portion facing the female joint 20 of the K segment. Specifically, at the aforementioned ends of the B segment in the circumferential direction, a female joint 20 is provided on the front side in the direction of excavation, and a male joint 10 is provided on the rear side in the direction of excavation.

[0048] In other words, one of the circumferentially adjacent K-segments and B-segments connected by the segment connector 1 is provided with a male joint 10, and the other of the adjacent K-segments and B-segments is provided with a female joint 20.

[0049] When the K-segment and B-segment are connected in the circumferential direction of the tunnel, the male joint 10 provided on the K-segment moves in the opposite direction to the excavation direction to engage with the female joint 20 provided on the B-segment, which engages with the male joint 10. Similarly, when the K-segment and B-segment are connected in the circumferential direction of the tunnel, the female joint 20 provided on the K-segment moves in the opposite direction to the excavation direction to engage with the male joint 10 provided on the B-segment. In other words, in the axial direction of the tunnel, the order of the male joint 10 and female joint 20 in the K-segment is different from the order of the male joint 10 and female joint 20 in the B-segment. The male joint 10 and female joint 20 provided on the K-segment and the male joint 10 and female joint 20 provided on the B-segment have the same configuration.

[0050] The male joint 10 and female joint 20 are configured to fit together when the K segment is inserted between two B segments. That is, by moving the K segment in the opposite direction to the excavation direction relative to the B segments, the male joint 10 and female joint 20 of the segment connector 1 fit together, and the K segment and B segment are connected in the circumferential direction.

[0051] The segment connector 1 of the present invention has an axial movement restricting portion 30. The axial movement restricting portion 30 restricts the relative movement of the K segment and the B segment in the opposite direction to the direction of fitting. This prevents the K segment, which is circumferentially connected to the two B segments, from coming loose between the two B segments when the male connector 10 and the female connector 20 are fitted together. Details of the axial movement restricting portion 30 will be described later.

[0052] (Configuration of segment connector) Next, the configuration of the segment connector 1 according to this embodiment will be described in detail with reference to Figures 2A to 6C. In Figures 4A to 6C, for illustrative purposes, the segment to which the segment connector 1 is attached is omitted from the illustration. Also, below, two segments connected by the segment connector 1 will be referred to as a pair of segments.

[0053] Figures 4A and 4B show the schematic configuration of the segment connector 1. Specifically, Figure 4A is a view of the segment connector 1 in the thickness direction of the segment. Figure 4B is a view of the segment connector 1 in the axial direction of the tunnel. Figure 5 shows the schematic configuration of the circumferential movement portion 31 of the axial movement restricting portion 30.

[0054] Figures 6A to 6C illustrate the operation of the axial movement restricting portion 30 when the male joint 10 and female joint 20 of the segment connector 1 are connected. Specifically, Figure 6A shows the position of the axial movement restricting portion 30 when the male joint 10 begins to move in the direction of fitting with the female joint 20. Figure 6B shows the position of the axial movement restricting portion 30 while the male joint 10 is moving in the direction of fitting with the female joint 20. Figure 6C shows the position of the axial movement restricting portion 30 when the male joint 10 and female joint 20 are fitted together. In Figures 4A and 6A, the white arrows indicate the direction of movement of the male joint 10 relative to the female joint 20 (the direction in which the male joint 10 fits with the female joint 20). Note that in Figures 4A, 4B and 6A to 6C, for explanatory purposes, the temporary fixing portion 70 and the circumferential movement portion 31 of the axial movement restricting portion 30 are shaded.

[0055] As shown in Figure 4A, the male joint 10 has a male joint body 11 and two anchor bars 12.

[0056] As shown in Figures 2A, 2B, 4A, and 4B, the male joint body 11 is plate-shaped and extends in the axial direction, protruding circumferentially from the circumferential end of the segment on which the male joint 10 is provided. The male joint body 11 is made of, for example, metal. The male joint body may be made of a material other than metal, such as resin.

[0057] As shown in Figures 2A, 2B, 4A, and 4B, the two anchor bars 12 are axial and connected to the male joint body 11 so as to extend inward from the male joint body 11 into the segment. The two anchor bars 12 are embedded in the segment. Thus, the male joint body 11 is fixed to the segment by the two anchor bars 12. As shown in Figures 2A to 3B, the anchor bars 12 extend inward from the circumferential end of the segment in which the male joint 10 is provided.

[0058] As shown in Figures 4A and 4B, the male joint body 11 has a male fitting portion 13 at its circumferential tip 11a. The male fitting portion 13 is the part that is housed in the insertion groove 23a of the female fitting portion 23 of the female joint 20, which will be described later, when the male joint 10 and the female joint 20 are fitted together.

[0059] More specifically, as shown in Figure 4B, the male joint body 11 has a progressively smaller thickness from the base end to which the anchor bars 12 are connected towards the tip 11a, and the tip 11a has a larger thickness. This larger thickness constitutes the male fitting portion 13.

[0060] The male fitting portion 13 extends from one axial direction to the other at its circumferential tip portion 11a. When the direction in which the male fitting portion 10 fits into the female fitting portion 20 is considered to be forward, when the male fitting portion 13 is inserted into the female fitting portion 23, the front end 13a of the male fitting portion 13 is first inserted into the insertion groove 23a of the female fitting portion 23.

[0061] The rear end 13b of the male fitting portion 13 functions as a contacted portion 41 that comes into contact with the contact portion 32 of the circumferential moving portion 31 in the axial movement restricting portion 30, which will be described later.

[0062] As shown in Figure 4A, the female joint 20 has a female joint body 21 and two anchor bars 22.

[0063] As shown in Figures 2A, 2B, 4A, and 4B, the female joint body 21 extends axially and has a female fitting portion 23 at its circumferential end portion 21a. The female joint body 21 is located circumferentially inward relative to the circumferential end of the segment on which the female joint 20 is provided. The female joint body 21 is made of, for example, metal. The female joint body may be made of a material other than metal, such as resin.

[0064] As shown in Figures 2A, 2B, 4A, and 4B, the two anchor bars 22 are axial and connected to the female joint body 21 so as to extend inward from the female joint body 21 into the segment. The two anchor bars 22 are embedded in the segment. Thus, the female joint body 21 is fixed to the segment by the two anchor bars 22. As shown in Figures 2A to 3B, the anchor bars 22 extend inward from the circumferential end of the segment in which the female joint 20 is provided.

[0065] As shown in Figures 4A and 4B, the female fitting portion 23 has an insertion groove 23a that extends in the axial direction. The insertion groove 23a has an opening 23b that opens in the axial direction at one end in the axial direction, and an axial end 23d at the other end in the axial direction. The insertion groove 23a is located at the tip portion 21a of the female joint body portion 21 and has a slit 23c that extends in the axial direction.

[0066] The axial depth of the insertion groove 23a is longer than the axial length of the male fitting portion 13. The insertion groove 23a has a shape into which the male fitting portion 13 can be inserted. The front end 13a of the male fitting portion 13 is inserted into the insertion groove 23a from the opening 23b of the insertion groove 23a. When the male fitting portion 13 is inserted to a predetermined position in the insertion groove 23a, the axial end face of the K segment comes into contact with the axial end face of the existing segment ring. This restricts the male fitting portion 13 from advancing further within the insertion groove 23a. In addition, the circumferential end face of the K segment comes into contact with the circumferential end face of the adjacent B segment in the circumferential direction. Furthermore, with the male fitting portion 13 inserted into the insertion groove 23a, the K segment is restricted from moving away from the adjacent B segment in the circumferential direction, and the K segment is also restricted from moving in the thickness direction relative to the adjacent B segment.

[0067] In this specification, the state in which the male fitting portion 13 is inserted into the insertion groove 23a, thereby restricting the relative movement of the pair of segments in the circumferential and thickness directions, is referred to as the fitting of the male joint 10 and the female joint 20. Furthermore, the direction in which the front end 13a of the male fitting portion 13 moves toward the axial end 23d of the insertion groove 23a is referred to as the direction in which the male joint 10 and the female joint 20 are fitted together.

[0068] Figure 6C shows the male connector 10 and the female connector 20 in a fitted state. As described above, the axial depth of the insertion groove 23a is longer than the axial length of the male fitting portion 13. Therefore, as shown in Figure 6C, when the male connector 10 and the female connector 20 are fitted together, the male fitting portion 13 is located within the insertion groove 23a.

[0069] As shown in Figures 4A, 4B, and 6C, in the female fitting portion 23, when the male joint 10 and the female joint 20 are fitted together, a recess 24 is provided on the inner surface of the insertion groove 23a behind the male fitting portion 13 (in the opposite direction to the fitting direction), with a recess 24 that is recessed in the circumferential direction. The circumferential movement portion 31 of the axial movement restricting portion 30, which will be described later, is housed in the recess 24. In addition, the temporary fixing portion 70 of the axial movement restricting portion 30, which will be described later, is housed in the insertion groove 23a.

[0070] Next, the configuration and operation of the axial movement restricting section 30 will be described with reference to Figures 4A to 6C. The axial movement restricting section 30 has a circumferential movement section 31, a contacted section 41, and a temporary fixing section 70. In the segment connector 1, the circumferential movement section 31 is provided on either the male joint 10 or the female joint 20. The contacted section 41 is provided on the other of the male joint 10 or the female joint 20.

[0071] As shown in Figures 4A and 4B, in this embodiment, the circumferential movement portion 31 of the axial movement restricting portion 30 is provided on the female joint 20. The circumferential movement portion 31 is positioned so as to always overlap with the female joint 20 when viewed in the axial direction. Specifically, the circumferential movement portion 31 is housed in the recess 24 of the female fitting portion 23 of the female joint 20. The movement of the circumferential movement portion 31 in the thickness direction and axial direction of the segment is restricted by the inner surface of the recess 24. On the other hand, the circumferential movement portion 31 is movable in the circumferential direction.

[0072] As shown in Figure 5, in this embodiment, the circumferential moving part 31 has a contact part 32 and a compression coil spring 33.

[0073] The contact portion 32 is supported by a compression coil spring 33 located within the recess 24. In this embodiment, the direction of expansion and contraction of the compression coil spring 33 is circumferential. That is, the compression coil spring 33 elastically supports the contact portion 32 with respect to the bottom of the recess 24. When compressed, the compression coil spring 33 biases the contact portion 32 in a direction that moves it out of the recess 24. In other words, the contact portion 32 is movable in the circumferential direction by the deformation of the compression coil spring 33 located within the recess 24. Hereinafter, in the circumferential direction in which the contact portion 32 moves, the direction in which the compression coil spring 33 is compressed will be referred to as the compression direction, and the opposite direction will be referred to as the decompression direction.

[0074] As shown in Figure 5, the contact portion 32 has a tip portion 32a on the side opposite to the portion to which the compression coil spring 33 is connected. The axial length of the tip portion 32a decreases towards the tip. That is, the tip portion 32a has an inclined surface 32b on the rear side (rear side in the fitting direction) of the direction in which the male joint 10 moves relative to the female joint 20, such that the axial length decreases towards the tip. The inclined surface 32b extends in a direction inclined with respect to the direction in which the male joint 10 and the female joint 20 are fitted together, when the female joint 20 is viewed in the thickness direction of the segment. The inclined surface 32b is also inclined with respect to the circumferential direction when viewed in the thickness direction.

[0075] The tip of the contact portion 32 protrudes from the recess 24 when the compression coil spring 33 is compressed by the temporary fixing portion 70. Therefore, as shown in Figure 6A, when the male fitting portion 13 is inserted into the insertion groove 23a, the male fitting portion 13 comes into contact with the tip 32a of the contact portion 32. Thus, in this embodiment, the contact portion 32 has an inclined surface 32b that extends in a direction inclined with respect to the fitting direction at the portion that comes into contact with the male fitting 10 when the male fitting 10 moves in the direction of fitting with the female fitting 20.

[0076] With the above configuration, the contact portion 32 that the male fitting portion 13 contacts is pushed in the compression direction within the circumferential direction by the male fitting portion 13. As a result, as shown in Figure 6B, when the male joint 10 moves in the direction of fitting with the female joint 20, the contact portion 32 moves to a position that does not overlap with the male joint 10 when viewed in the axial direction. Therefore, interference with the fitting of the male joint 10 and the female joint 20 is prevented.

[0077] As described above, when the contact portion 32 moves in the compression direction, the compression coil spring 33 that elastically supports the contact portion 32 is compressed. Therefore, the compression coil spring 33 biases the contact portion 32 outward from the recess 24.

[0078] In this embodiment, the contacted portion 41 is provided on the male joint 10. The contacted portion 41 is located in the male joint 10 at a position that overlaps with the contacted portion 32 of the circumferentially moving portion 31, which moves in the non-compression direction when the male joint 10 and the female joint 20 are fitted together, when viewed in the axial direction. In this embodiment, the rear end 13b of the male fitting portion 13 in the male joint 10 functions as the contacted portion 41.

[0079] As described above, when the male joint 10 and the female joint 20 are fitted together, the recess 24 is located behind the male fitting portion 13. Therefore, as shown in Figure 6C, when the male joint 10 and the female joint 20 are fitted together, the contact portion 32, which is biased outward from the recess 24 by the compression coil spring 33, protrudes behind the male fitting portion 13 within the insertion groove 23a.

[0080] The rear end 13b of the male fitting portion 13, which is the contacted portion 41, coincides with the contact portion 32 of the circumferentially moving portion 31 that moves in the non-compression direction when the male joint 10 and female joint 20 are fitted together, as viewed from the axial direction. In other words, when the male joint 10 and female joint 20 are fitted together, the contact portion 32 of the circumferentially moving portion 31 provided on the female joint 20 is located behind the contacted portion 41 provided on the male joint 10.

[0081] As described above, the circumferential movement portion 31 is restricted from moving in the thickness direction and axial direction by the inner surface of the recess 24. Therefore, the contact portion 32 of the circumferential movement portion 31 is located behind the rear end 13b of the male fitting portion 13, which is the contacted portion 41, thereby restricting the male joint 10 from moving in the direction opposite to the fitting direction. Thus, the K segment to which the male joint 10 is provided is restricted by the axial movement restricting portion 30 from moving in the direction opposite to the fitting direction with respect to the B segment.

[0082] The temporary fixing portion 70 temporarily fixes the contact portion 32 in a predetermined position before the male fitting portion 13 is inserted into the insertion groove 23a. As shown in Figures 4A, 4B, and 6A, the temporary fixing portion 70 is positioned on the tip side of the circumferentially movable portion 31 within the insertion groove 23a before the male fitting portion 13 is inserted into the insertion groove 23a. Specifically, a portion of the temporary fixing portion 70 is located within the slit 23c of the insertion groove 23a, and the remainder protrudes into the insertion groove 23a. The protruding tip of the temporary fixing portion 70 is in contact with the tip of the circumferentially movable portion 31.

[0083] The temporary fixing portion 70 is pushed in the direction that the male joint 10 and female joint 20 are fitted together by the front end 13a of the male fitting portion 13 when the male fitting portion 13 is inserted into the insertion groove 23a. As a result, as shown in Figure 6C, the temporary fixing portion 70 moves into the space S between the front end 13a and the axial end 23d of the male fitting portion 13 within the insertion groove 23a. The temporary fixing portion 70 may be made of a material having a predetermined hardness and a predetermined modulus of elasticity. For example, the temporary fixing portion 70 may be made of expanded polystyrene.

[0084] As described above, the segment connector 1 according to this embodiment includes an axial movement restricting portion 30 that restricts the relative movement of the pair of segments in the opposite direction to the fitting direction. The axial movement restricting portion 30 includes a circumferential movement portion 31 provided on the female joint 20 at a position that always overlaps with the female joint 20 when viewed in the axial direction, and that is capable of moving in the circumferential direction while restricting the movement of the segment in the thickness direction and axial direction, and a contacted portion 41 provided on the male joint 10 at a position that overlaps with the circumferential movement portion 31 when the male joint 10 and the female joint 20 are fitted together and have moved in the circumferential direction when viewed in the axial direction.

[0085] Thus, the segment connector 1, which connects a pair of segments aligned in the circumferential direction of the tunnel, has an axial movement restricting portion 30 that restricts relative movement of the pair of segments in the opposite direction to the direction in which they fit together. Therefore, it is not necessary to provide a member on the segments, separate from the segment connector 1, to restrict the movement of the segments in the opposite direction to the direction in which they fit together. Consequently, the configuration and connection structure of the pair of segments can be simplified. Furthermore, since it is not necessary to provide space on the segments for the axial movement restricting portion 30, separate from the segment connector 1, a reduction in the strength of the pair of segments can be suppressed.

[0086] Furthermore, in the axial movement restricting portion 30, the contact portion 32 of the circumferential movement portion 31 moves circumferentially while restricting the movement of the segment in the thickness direction and axial direction, and contacts the contacted portion 41. Compared to the case where the member restricting the movement of the segment in the opposite direction to the fitting direction is configured to move in the thickness direction of the segment, this makes it possible to make the thickness of each segment more compact while suppressing a decrease in the strength of each segment in the thickness direction.

[0087] In this embodiment, the circumferential movement portion 31 is provided on the female joint 20 so as to be located at the rear end of the direction of movement of the male joint 10 relative to the female joint 20 in the segment connector 1. That is, the male joint 10 is restricted from moving backward in the direction of movement by the circumferential movement portion 31 located at the rear end of the direction of movement of the male joint 10 relative to the female joint 20. This makes it possible to more reliably prevent the pair of segments arranged in the circumferential direction from moving relative to each other in the direction opposite to the direction of fitting.

[0088] (Segment linking method) Next, with reference to Figures 2B, 6A to 6C, and 7, a method for connecting a pair of segments arranged in the circumferential direction using the segment connector 1 according to the present invention will be described. Figure 7 is a flowchart showing the steps of the segment connecting method.

[0089] As shown in Figure 7, the segment connection method includes a temporary fixing step S1, a segment assembly step S2, and a segment movement restriction step S3.

[0090] The temporary fixing step S1 is a step of temporarily fixing the circumferentially movable portion 31 of the segment connector 1 to a predetermined position in the circumferential direction.

[0091] As shown in Figure 6A, in the temporary fixing step S1, the temporary fixing portion 70 is positioned between the contact portion 32 of the circumferentially movable portion 31 and the inner surface of the insertion groove 23a of the female joint 20. This fixes the position of the contact portion 32 with respect to the inner surface of the insertion groove 23a, thereby preventing the circumferentially movable portion 31 from coming out of the recess 24.

[0092] Segment assembly step S2 is the process of inserting the K segment between the two B segments, as shown in Figure 2B. In segment assembly step S2, the K segment is moved axially relative to the B segments. This moves the male joint 10 in the direction of fitting with the female joint 20, and the male fitting portion 13 of the male joint 10 is inserted into the insertion groove 23a of the female fitting portion 23 of the female joint 20.

[0093] The segment movement restriction step S3 is a step in which the male joint 10 and the female joint 20 are fitted together, as shown in Figures 6A to 6C, and relative movement of the pair of segments connected by the segment connector 1 in the opposite direction to the fitting direction is restricted.

[0094] As shown in Figure 6A, the male fitting portion 13 is inserted into the insertion groove 23a by moving a segment (not shown) (segment K in Figure 2B) in the direction of fitting with an adjacent segment (segment B in Figure 2B) in the circumferential direction. The front end 13a of the male fitting portion 13 inserted into the insertion groove 23a pushes the contact portion 32 of the circumferential moving portion 31, compressing the compression coil spring 33 and moving the contact portion 32 into the recess 24. At this time, the front end 13a of the male fitting portion 13 pushes the temporary fixing portion 70, which is sandwiched between the tip of the contact portion 32 and the inner surface of the insertion groove 23a, in the direction of fitting, moving it into the space S between the front end 13a and the axial end 23d of the male fitting portion 13 within the insertion groove 23a. Thus, the fixing of the contact portion 32 by the temporary fixing portion 70 is released.

[0095] Furthermore, by moving a segment (not shown) (segment K in Figure 2B) in the direction of fitting with an adjacent segment in the circumferential direction (segment B in Figure 2B), as shown in Figure 6B, the contact portion 32 of the circumferential moving portion 31 is pushed in the compression direction by the tip portion 11a of the male joint body portion 11 where the male fitting portion 13 is located, and is housed in the recess 24. Also, the front end 13a of the male fitting portion 13 moves the temporary fixing portion 70 to the axial end portion 23d of the insertion groove 23a.

[0096] By moving a segment (not shown) (segment K in Figure 2B) further in the direction of fitting with an adjacent segment in the circumferential direction (segment B in Figure 2B), the fitting of the male joint 10 and the female joint 20 is completed, as shown in Figure 6C. In other words, the pair of segments are connected by the segment connector 1.

[0097] As described above, when the male joint 10 and the female joint 20 are fitted together, the recess 24 is located behind the rear end 13b of the male fitting portion 13. Therefore, the contact portion 32 moves in the non-compression direction due to the restoring force of the compression coil spring 33 and protrudes behind the male fitting portion 13 in the insertion groove 23a. As a result, the contact portion 32 of the circumferentially moving portion 31 comes into contact with the rear end 13b of the male fitting portion 13, which is the contacted portion 41. Thus, the movement of the K segment relative to the B segment in the direction opposite to the fitting direction is restricted.

[0098] In other words, the segment connection method according to this embodiment includes: a temporary fixing step S1 in which the circumferentially movable portion 31 of the segment connector 1 is temporarily fixed to a predetermined position in the circumferential direction of the tunnel by a temporary fixing portion 70; a segment assembly step S2 in which a pair of segments are moved relative to each other in the axial direction of the tunnel, thereby moving the male joint 10 in a direction to fit with the female joint 20; and a segment movement restricting step S3 in which the temporary fixing portion 70 is removed by moving the male joint 10 relative to the female joint 20 in the direction to fit, thereby moving the circumferentially movable portion 31 in a non-compression direction to contact the contacted portion 41 of the segment connector 1.

[0099] This allows a pair of segments aligned circumferentially in the tunnel to be connected by the segment connector 1, while the circumferential moving portion 31 and contacted portion 41 of the segment connector 1 prevent the pair of segments from moving relative to each other in the axial direction of the tunnel. Therefore, since there is no need to provide a separate member to restrict the relative axial movement of the pair of segments, the configuration and connection structure of the pair of segments can be simplified, and a reduction in the strength of the pair of segments can be suppressed.

[0100] (Modification 1 of Embodiment 1) Next, with reference to Figures 8A to 8C, a segment connector 101 according to a modified example 1 of Embodiment 1 will be described. The segment connector 101 comprises a male connector 10, a female connector 20, and an axial movement restricting portion 130. In the following, components identical to those in Embodiment 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0101] Figure 8A shows the position of the axial movement restricting portion 130 when the male joint 10 begins to move in the direction of fitting with the female joint 20. Figure 8B shows the position of the axial movement restricting portion 130 while the male joint 10 is moving in the direction of fitting with the female joint 20. Figure 8C shows the position of the axial movement restricting portion 130 when the male joint 10 and the female joint 20 are fitted together. In Figure 8A, the white arrow indicates the direction of movement of the male joint 10 relative to the female joint 20 (the direction in which the male joint 10 fits with the female joint 20). Note that in Figures 8A to 8C, for explanatory purposes, the temporary fixing portion 70 and the circumferential movement portion 31 of the axial movement restricting portion 130 are shaded.

[0102] In this modified example, the axial movement restricting portion 130 has a circumferential movement portion 31, a contacted portion 41, a circumferential positioning portion 151, and a temporary fixing portion 70. In this modified example as well, the contacted portion 41 is the rear end 13b of the male fitting portion 13.

[0103] The circumferential positioning portion 151 is provided at the rear end 13b of the male fitting portion 13 in the male fitting body portion 11 of the male fitting 10. The circumferential positioning portion 151 extends axially from the rear end 13b of the male fitting portion 13. That is, the circumferential positioning portion 151 is provided on the male fitting 10, a portion of which functions as the contacted portion 41. The circumferential positioning portion 151 may be connected to the rear end 13b of the male fitting portion 13, or it may be formed integrally with the male fitting portion 13.

[0104] As shown in Figure 8C, the circumferential positioning portion 151 is configured such that, when viewed axially from the male joint 10 and the female joint 20, the contact portion 32 of the circumferential moving portion 31 provided on the female joint 20 and the contacted portion 41 provided on the male joint 10 overlap, and the tip of the contact portion 32 makes contact. This prevents the contact portion 32 of the circumferential moving portion 31, which has moved in the non-compressive direction while the male joint 10 and the female joint 20 are fitted together, from moving further in the non-compressive direction than the circumferential positioning portion 151.

[0105] In other words, the circumferential positioning unit 151 positions the contact portion 32 of the circumferential moving unit 31, which has moved to a position where it overlaps with the contacted portion 41 when viewed in the axial direction, when the male joint 10 and the female joint 20 are fitted together, so that the male joint 10 and the female joint 20 overlap with the contacted portion 41 when viewed in the axial direction.

[0106] This allows the circumferentially movable portion 31 to be positioned in a circumferential location where it overlaps with the contacted portion 41 when viewed axially with respect to the male joint 10 and the female joint 20. Therefore, the circumferentially movable portion 31 and the contacted portion 41 can more reliably prevent the pair of segments from moving relative to each other in the opposite direction to the direction in which they are fitted together.

[0107] (Modification 2 of Embodiment 1) Next, with reference to Figures 9A to 9C, a segment connector 201 according to a modified example 2 of Embodiment 1 will be described. The segment connector 201 comprises a male joint 210, a female joint 20, an axial movement restricting portion 230, and a temporary fixing portion 70. In the following, components identical to those in Embodiment 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0108] Figure 9A shows the position of the axial movement restricting portion 230 when the male joint 210 begins to move in the direction of fitting with the female joint 20. Figure 9B shows the position of the axial movement restricting portion 230 while the male joint 210 is moving in the direction of fitting with the female joint 20. Figure 9C shows the position of the axial movement restricting portion 230 when the male joint 210 and the female joint 20 are fitted together. In Figure 9A, the white arrow indicates the direction of movement of the male joint 210 relative to the female joint 20 (the direction in which the male joint 210 fits with the female joint 20). Note that in Figures 9A to 9C, for explanatory purposes, the temporary fixing portion 70 and the circumferential movement portion 31 of the axial movement restricting portion 230 are shaded.

[0109] In this modified example, the male joint 210 has a male joint body 211 and two anchor bars 12. The male joint body 211 has a male fitting portion 213 at the circumferential tip portion 211a of the male joint body 211.

[0110] The male fitting portion 213 has a notch 214 at the corner of the rear end 213b of the tip portion 211a of the male joint body portion 211. The notch 214 has a shape that allows the tip portion of the contact portion 32 of the circumferential moving portion 31 of the axial movement restricting portion 230, which moves in the non-compression direction when the male joint 210 and the female joint 20 are fitted together, to be locked.

[0111] In this modified example, the axial movement restricting portion 230 has a circumferential movement portion 31, a contacted portion 241, and a circumferential positioning portion 251.

[0112] In this modified example, the contacted portion 241 is a part of the notch 214 of the male joint 210. More specifically, the contacted portion 241 is the part of the notch 214 that overlaps with the contact portion 32 of the circumferentially moving portion 31 that moves in the non-compression direction when viewed axially with the male joint 210 and the female joint 20. A part of the notch 214 is the part that faces the tip of the contact portion 32 of the circumferentially moving portion 31 that moves in the non-compression direction when the male joint 210 and the female joint 20 are fitted together.

[0113] The circumferential positioning portion 251 is part of the notch portion 214 of the male joint 210. More specifically, the circumferential positioning portion 251 is the portion of the notch portion 214 that extends in the axial direction. As shown in Figure 9C, the tip of the contact portion 32 of the circumferential moving portion 31 provided on the female joint 20 and the contacted portion 241 provided on the male joint 210 can make contact with the circumferential positioning portion 251 when they are in an overlapping state in the axial direction. This prevents the contact portion 32 of the circumferential moving portion 31, which has moved in the non-compressive direction when the male joint 10 and the female joint 20 are fitted together, from moving further in the non-compressive direction than the circumferential positioning portion 251.

[0114] In other words, the circumferential positioning unit 251 positions the contact portion 32 of the circumferential moving unit 31, which has moved to a position that overlaps with the contacted portion 241 when viewed in the axial direction, when the male joint 210 and the female joint 20 are fitted together, so that the male joint 210 and the female joint 20 overlap with the contacted portion 241 when viewed in the axial direction.

[0115] As described above, the notch 214 functions as the contacted portion 241 of the axial movement restricting portion 230, and also functions as the circumferential positioning portion 251 of the axial movement restricting portion 230.

[0116] With the above configuration, the male joint 210 and the female joint 20 can be positioned in the circumferential direction, with the contact portion 32 of the circumferential moving portion 31 overlapping the contacted portion 241, without the need for separate components. Therefore, the circumferential moving portion 31 and the contacted portion 241 can more reliably prevent the pair of segments from moving relative to each other in the opposite direction to the fitting direction.

[0117] (Embodiment 2) Next, the segment connector 301 according to Embodiment 2 will be described with reference to Figures 10A to 10C and Figure 11. The segment connector 301 comprises a male connector 10, a female connector 320, and an axial movement restricting portion 330. In the following, components identical to those in Embodiment 1 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0118] Figure 10A shows the position of the axial movement restricting portion 330 when the male joint 10 begins to move in the direction of fitting with the female joint 320. Figure 10B shows the position of the axial movement restricting portion 330 while the male joint 10 is moving in the direction of fitting with the female joint 320. Figure 10C shows the position of the axial movement restricting portion 330 when the male joint 10 and the female joint 320 are fitted together. Figure 11 is a diagram showing the schematic configuration of the circumferential movement portion 331 of the axial movement restricting portion 330. In Figures 10A and 11, the white arrows indicate the direction of movement of the male joint 10 relative to the female joint 320 (the direction in which the male joint 10 fits with the female joint 320). Note that in Figures 10A to 10C, the circumferential movement portion 331 of the axial movement restricting portion 330 is shaded for explanatory purposes.

[0119] The female joint 320 has a female joint body 321 and two anchor bars 22. The female joint body 321 has a female fitting portion 323 at its circumferential tip 321a.

[0120] The female fitting portion 323 has an insertion groove 323a that extends in the axial direction, similar to Embodiment 1. The male fitting portion 13 of the male joint 10 is housed in the insertion groove 323a. This allows the male joint 10 and the female joint 320 to be fitted together.

[0121] As shown in Figure 10C, in the female fitting portion 323, when the male joint 10 and the female joint 320 are fitted together, a circumferential recess 324 is provided on the inner surface of the insertion groove 323a behind the male fitting portion 13 (in the opposite direction to the fitting direction). The tip of the contact portion 332 of the circumferential moving portion 331 of the axial movement restricting portion 330, which moves in the non-compression direction when the male joint 10 and the female joint 320 are fitted together, is housed in the recess 324.

[0122] In this embodiment, the axial movement restricting portion 330 has a circumferential movement portion 331, a contacted portion 341, and a circumferential positioning portion 351. In this embodiment, the circumferential movement portion 331 is provided on the male joint 10. The contacted portion 341 is provided on the female joint 320.

[0123] As shown in Figure 11, the circumferential moving portion 331 has a contact portion 332, a compression coil spring 33, and a mounting portion 334.

[0124] The mounting portion 334 extends rearward from the rear end 13b of the male fitting portion 13 of the male joint 10. The compression coil spring 33 is connected to the mounting portion 334 and extends from the mounting portion 334 in the circumferential direction of the segment and in the direction in which the tip portion 11a of the male joint body portion 11 is located. The compression coil spring 33 elastically supports the contact portion 332 with respect to the mounting portion 334.

[0125] In its compressed state, the compression coil spring 33 biases the contact portion 332 such that it protrudes outward from the circumferential position of the tip portion 11a of the male joint body 11. In other words, the compression coil spring 33 biases the contact portion 332 in the direction in which the anchor reinforcement 22 of the female joint 320 is located when the male joint 10 and the female joint 320 are fitted together.

[0126] The contact portion 332 is elastically supported by a compression coil spring 33. That is, the contact portion 332 is movable in the circumferential direction by the deformation of the compression coil spring 33.

[0127] The contact portion 332 has a tip portion on the opposite side from the portion to which the compression coil spring 33 is connected, where the axial length decreases towards the tip of the contact portion 332. The tip portion has an inclined surface 332a on the front side (front side in the fitting direction) of the male joint 10 in the direction of movement relative to the female joint 320, such that the axial length decreases towards the tip. The inclined surface 332a extends in a direction inclined with respect to the fitting direction when the male joint 10 is viewed in the thickness direction of the segment. Also, the inclined surface 332a is inclined with respect to the circumferential direction when viewed in the thickness direction.

[0128] As described above, the tip of the contact portion 332 protrudes outward from the circumferential position of the tip 11a of the male joint body portion 11. Therefore, as shown in Figure 10B, when the male fitting portion 13 is inserted into the insertion groove 323a of the female fitting portion 323, the tip of the contact portion 332 contacts the opening of the insertion groove 323a. Thus, in this embodiment, as shown in Figure 11, the contact portion 332 has an inclined surface 332a that extends in a direction inclined with respect to the fitting direction at the portion that contacts the female joint 320 when the male joint 10 moves in the direction of fitting with the female joint 320.

[0129] The contact portion 332, which is in contact with the opening of the insertion groove 323a, is pushed in the compression direction. Therefore, when the male joint 10 moves in the direction of fitting with the female joint 320, the contact portion 332 is moved by the female joint 320 so that the tip of the contact portion 332 is positioned inside the insertion groove 323a. This prevents interference with the fitting of the male joint 10 and the female joint 320.

[0130] As the contact portion 332 moves in the compression direction, the compression coil spring 33 that elastically supports the contact portion 332 is compressed. Therefore, the compression coil spring 33 biases the contact portion 332 in the direction in which the anchor reinforcement 22 of the female joint 320 is located.

[0131] In this embodiment, the contacted portion 341 is a part of the recess 324 of the female joint 320. The part of the recess 324 that is the contacted portion 341 is located in the female joint 320 at a position that overlaps with the contact portion 332 of the circumferentially moving portion 331 that moves in the non-compression direction when the male joint 10 and the female joint 320 are fitted together, when viewed in the axial direction. Therefore, a part of the recess 324 contacts the contact portion 332 of the circumferentially moving portion 331 that moves in the non-compression direction when the male joint 10 and the female joint 320 are fitted together.

[0132] The circumferential positioning portion 351 is part of the recess 324 of the female joint 320. As shown in Figure 10C, when viewing the male joint 10 and the female joint 320 in the axial direction, the circumferential tip of the contact portion 332 of the circumferential moving portion 331 on the male joint 10 and the contacted portion 341 on the female joint 320 overlap, and the circumferential positioning portion 351 makes contact with the circumferential positioning portion 351. In other words, when the male joint 10 and the female joint 320 are fitted together, the circumferential positioning portion 351 positions the contact portion 332 of the circumferential moving portion 331, which has moved to a position that overlaps with the contacted portion 341 when viewed in the axial direction, at the aforementioned circumferential position where it overlaps with the contacted portion 341.

[0133] As described above, when the male joint 10 and the female joint 320 are fitted together, the recess 324 is located rearward relative to the male fitting portion 13. The contact portion 332 of the circumferential moving portion 331 is biased by the compression coil spring 33 in the direction in which the anchor reinforcement 22 of the female joint 320 is located. Therefore, as shown in Figure 10C, when the male joint 10 and the female joint 320 are fitted together, the contact portion 332 moves toward the bottom surface of the recess 324 of the male fitting portion 13 within the insertion groove 323a. Thus, the tip of the contact portion 332 is housed within the recess 324.

[0134] The contact portion 332 of the circumferentially moving portion 331, whose tip is housed within the recess 324, has its movement restricted in the thickness direction, axial direction, and circumferential direction by the inner surface of the recess 324. Therefore, the recess 324 functions as the contacted portion 341 of the axial movement restricting portion 330, and also functions as the circumferential positioning portion 351 of the axial movement restricting portion 330.

[0135] In other words, the contact portion 332 of the circumferentially moving portion 331 is located on the male joint 10 in a position that always overlaps with the male joint 10 when viewed in the axial direction, and is provided so as to be movable in the circumferential direction of the segment. The contacted portion 341 is located on the female joint 320 in a position that overlaps with the contact portion 332 of the circumferentially moving portion 331 when the male joint 10 and the female joint 320 are fitted together, when viewed in the axial direction, and restricts the movement of the contact portion 332 of the moved circumferentially moving portion 331 in the thickness direction and axial direction of the segment.

[0136] Although not specifically shown in the figures, the contact portion 332 of the circumferentially moving portion 331 is provided on the male joint 10 in such a way that the movement of the segment in the thickness direction and axial direction is restricted.

[0137] This prevents the male fitting portion 13 housed in the insertion groove 323a from moving in the opposite direction to the fitting direction. Therefore, the K segment, to which the male joint 10 is provided, is restricted by the axial movement restricting portion 330 from moving in the opposite direction to the fitting direction relative to the B segment.

[0138] Therefore, a pair of segments aligned circumferentially in the tunnel are connected by the segment connector 301, and the circumferential moving portion 331 and the contacted portion 341 of the segment connector 301 prevent the pair of segments from moving relative to each other in the axial direction of the tunnel. Thus, there is no need to provide a separate member to restrict the relative axial movement of the pair of segments, in addition to the segment connector 301, which simplifies the configuration and connection structure of the pair of segments and also suppresses a decrease in the strength of the pair of segments.

[0139] (Embodiment 3) Next, with reference to Figures 12A to 12D, the segment connector 401 according to Embodiment 3 will be described. The segment connector 401 comprises a male joint 10, a female joint 420, and an axial movement restricting part 430. In the following, components identical to those in Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted.

[0140] Figure 12A shows the position of the axial movement restricting portion 430 when the male joint 10 begins to move in the direction of fitting with the female joint 420. Figures 12B and 12C show the position of the axial movement restricting portion 430 while the male joint 10 is moving in the direction of fitting with the female joint 420. Figure 12D shows the position of the axial movement restricting portion 430 when the male joint 10 and the female joint 420 are fitted together. In Figure 12A, the white arrow indicates the direction of movement of the male joint 10 relative to the female joint 420 (the direction in which the male joint 10 fits with the female joint 420). Note that in Figures 12A to 12D, the axial movement restricting portion 430 is shaded for illustrative purposes.

[0141] The female joint 420 has a female joint body 421 and two anchor bars 22. The female joint body 421 has a female fitting portion 423 at its circumferential tip 421a.

[0142] The female fitting portion 423 has an insertion groove 423a that extends in the axial direction, similar to Embodiment 1. The male fitting portion 13 of the male connector 10 is housed in the insertion groove 423a. This allows the male connector 10 and the female connector 420 to be fitted together.

[0143] In this embodiment, the female fitting portion 423 is provided with a groove 424 that is recessed in the circumferential direction on the inner surface of the insertion groove 423a on the side opposite to the tip portion 421a. The groove 424 extends axially along the insertion groove 423a. The circumferential movement portion 431 of the axial movement restricting portion 430, which will be described later, is housed within the groove 424.

[0144] The axial movement restricting portion 430 has a circumferential movement portion 431 and a contacted portion 441. In this embodiment, the circumferential movement portion 431 is provided on the female joint 420. The contacted portion 441 is provided on the male joint 10. In this embodiment, as in Embodiment 1, the rear end 13b of the male fitting portion 13 functions as the contacted portion 441.

[0145] The circumferentially movable portion 431 is composed of, for example, a plate-shaped member extending in the axial direction. The circumferentially movable portion 431 is housed in the groove 424 of the female fitting portion 423 of the female joint 420. The movement of the circumferentially movable portion 431 in the thickness direction and axial direction of the segment is restricted by the inner surface of the groove 424. That is, the circumferentially movable portion 431 is movable only in the circumferential direction. The circumferentially movable portion may also be composed of a leaf spring.

[0146] The circumferential moving part 431 has a moving part body 432 and a head part 433.

[0147] The movable part body 432 extends in the axial direction. The movable part body 432 is housed in the groove 424 with its longitudinal direction aligned with the longitudinal direction of the groove 424. The movable part body 432 is bent in the thickness direction between the front end 432a, which is located in front of the direction of movement of the male joint 10 relative to the female joint 420, and the rear end 432b, which is located behind the direction of movement, such that the front end 432a is further away from the bottom surface of the groove 424 than the rear end 432b. In other words, the movable part body 432 is configured such that when the front end 432a is pushed toward the bottom surface of the groove 424, the rear end 432b protrudes from the groove 424 into the insertion groove 423a.

[0148] As shown in Figure 12A, the head 433 protrudes in one circumferential direction from the rear end 432b of the movable body 432. More specifically, when viewed in the axial direction, the head 433 protrudes in one circumferential direction from the rear end 432b of the movable body 432 such that, when the male joint 10 and the female joint 420 are fitted together, the head 433, when moved to one circumferential direction, overlaps with the contacted portion 441. That is, as shown in Figure 12C, in the female fitting portion 423, when the male joint 10 and the female joint 420 are fitted together, the head 433 is located behind the male fitting portion 13 (in the opposite direction to the fitting direction).

[0149] As shown in Figure 12A, the movable part body 432 is positioned so that its front end 432a protrudes into the insertion groove 423a before the male fitting part 13 is inserted into the insertion groove 423a. Therefore, as shown in Figures 12B and 12C, when the male fitting part 13 is inserted into the insertion groove 423a, the front end 13a of the male fitting part 13 comes into contact with the front end 432a of the movable part body 432. As a result, the rear end 432b of the movable part body 432 protrudes into the insertion groove 423a. In other words, the movable part body 432 is provided on the female joint 420 such that when the male joint 10 comes into contact with the front end 432a in the direction of movement relative to the female joint 420, the rear end 432b in the direction of movement moves to one side in the circumferential direction and approaches the male joint 10.

[0150] The rear end 13b of the male fitting portion 13, which is the contacted portion 441, overlaps with the head 433 of the circumferentially movable portion 431, which has moved to one side in the circumferential direction when the male joint 10 and female joint 420 are fitted together, as viewed from the axial direction of the male joint 10 and female joint 420. That is, when the male joint 10 and female joint 420 are fitted together, the head 433 of the circumferentially movable portion 431 provided on the female joint 420 is located behind the contacted portion 441 provided on the male joint 10. Therefore, as shown in Figure 12D, the head 433 contacts the rear end 13b of the male fitting portion 13 when the male joint 10 and female joint 420 are fitted together. This restricts the male joint 10 from moving in the direction opposite to the direction of fitting. Therefore, the pair of segments provided with the male joint 10 and the female joint 420 are restricted by the axial movement restricting portion 430 from moving relative to each other in the opposite direction to the fitting direction.

[0151] As described above, the segment connector 401 according to this embodiment includes an axial movement restricting portion 430 that restricts the relative movement of the pair of segments in the opposite direction to the fitting direction. The axial movement restricting portion 430 has a circumferential movement portion 431 provided on the female joint 420 at a position that always overlaps with the female joint 420 when viewed in the axial direction, and that is movable in one circumferential direction while restricting the movement of the segment in the thickness direction and axial direction, and a contacted portion 441 provided on the male joint 10 at a position that overlaps with the circumferential movement portion 431 when the male joint 10 and the female joint 420 are fitted together and the circumferential movement portion 431 has moved to one circumferential direction when viewed in the axial direction.

[0152] Therefore, in this embodiment as well, the circumferential movement portion 431 contacts the rear end 13b of the male fitting portion 13, which is the contacted portion 441, thereby restricting the movement of the male fitting portion 13 in the direction opposite to the fitting direction. As a result, the male joint 10, on which the contacted portion 441 is provided, is restricted from moving in the direction opposite to the fitting direction relative to the female joint 420, on which the circumferential movement portion 431 is provided. Thus, the pair of segments provided with the male joint 10 and the female joint 420 are restricted by the axial movement restricting portion 430 from moving relative to each other in the direction opposite to the fitting direction.

[0153] Furthermore, the moving part body 432 of the circumferential moving part 431 in this embodiment is provided on the female joint 420 such that when the male joint 10 comes into contact with the front end 432a, the rear end 432b moves in the circumferential direction and approaches the male joint 10. In addition, the head 433 of the circumferential moving part 431 protrudes in one direction in the circumferential direction from the rear end of the moving part body 432 such that, when viewed in the axial direction, the rear end of the moving part body 432, which has moved to one direction in the circumferential direction when the male joint 10 and the female joint 420 are fitted together, overlaps with the contacted part 441.

[0154] In other words, when the male joint 10 comes into contact with the front end 432a of the movable part body 432 in the direction of movement of the male joint 10 relative to the female joint 420, the rear end 432b of the movable part body 432 moves to one side in the circumferential direction and approaches the male joint 10. That is, when the male joint 10 and the female joint 420 are fitted together, the rear end 432b of the movable part body 432 approaches the male joint 10. The head 433 provided on the rear end 432b overlaps with the contacted portion 441 provided on the male joint 10 when viewed in the axial direction. As a result, the head 433 prevents the K segment from moving in the opposite direction to the fitting direction relative to the B segment.

[0155] This allows a pair of segments aligned circumferentially in the tunnel to be connected by the segment connector 401, while the circumferential moving portion 431 and contacted portion 441 of the segment connector 401 prevent the pair of segments from moving relative to each other in the axial direction of the tunnel. Therefore, since there is no need to provide a separate member to restrict the relative axial movement of the pair of segments, the configuration and connection structure of the pair of segments can be simplified, and a reduction in the strength of the pair of segments can be suppressed.

[0156] (Embodiment 4) Next, with reference to Figures 13A to 13C, the segment connector 501 according to Embodiment 4 will be described. The segment connector 501 comprises a male connector 510, a female connector 520, and an axial movement restricting portion 530. In the following, components identical to those in Embodiment 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0157] Figure 13A shows the position of the axial movement restrictor 530 when the male joint 510 begins to move in the fitting direction with respect to the female joint 520. Figure 13B shows the position of the axial movement restrictor 530 while the male joint 510 is moving in the direction of fitting with respect to the female joint 520. Figure 13C shows the position of the axial movement restrictor 530 when the male joint 510 and the female joint 520 are fitted together. In Figure 13A, the white arrow indicates the direction of movement of the male joint 510 with respect to the female joint 520 (the direction in which the male joint 510 fits with respect to the female joint 520). Note that in Figures 13A to 13C, the axial movement restrictor 530 is shaded for illustrative purposes.

[0158] The male joint 510 has a male joint body 511 and two anchor bars 12. The male joint body 511 has a male fitting portion 513 at its circumferential tip 511a. The male fitting portion 513 is the part that is housed in the insertion groove 523a of the female fitting portion 523 of the female joint 520, which will be described later.

[0159] The male fitting portion 513 has a circumferential recess 511b in the central part of the tip portion 511a of the male joint body portion 511 when viewed in the thickness direction. The tip portion 532a of the circumferential movement portion 531 of the axial movement restricting portion 530 is housed within the recess 511b when the male joint 510 and the female joint 520 are fitted together.

[0160] The female joint 520 has a female joint body 521 and two anchor bars 22. The female joint body 521 has a female fitting portion 523 at its circumferential tip 521a. The female fitting portion 523 has an insertion groove 523a that extends axially, similar to Embodiment 1. The male fitting portion 513 of the male joint 510 is housed in the insertion groove 523a. This allows the male joint 510 and the female joint 520 to be fitted together.

[0161] In this embodiment, the female fitting portion 523 is provided with a circumferential recess 524 on the inner surface of the insertion groove 523a on the side opposite to the tip portion 521a. The recess 524 is located in the axial central portion of the insertion groove 523a when viewed in the thickness direction. More specifically, the recess 524 is located in an axial position that coincides with the axial position of the recess 511b of the male fitting body portion 511 when the male fitting 510 and the female fitting 520 are fitted together. The circumferential movement portion 531 of the axial movement restricting portion 530, which will be described later, is housed within the recess 524.

[0162] The axial movement restricting portion 530 has a circumferential movement portion 531, a contacted portion 541, and a circumferential positioning portion 551. In this embodiment, the circumferential movement portion 531 is provided on the female joint 520. The contacted portion 541 is provided on the male joint 510. In this embodiment, the recess 511b of the male fitting portion 513 functions as both the contacted portion 541 and the circumferential positioning portion 551.

[0163] The circumferentially movable portion 531 has a movement restricting portion 532 and an elastic support portion 533. The circumferentially movable portion 531 is housed in a recess 524 of the female joint 520. Therefore, the movement of the circumferentially movable portion 531 is restricted in the thickness direction and axial direction of the segment.

[0164] The movement restricting portion 532 is elastically supported against the bottom surface of the recess 524 of the female joint 520 by an elastic support portion 533 connected to its circumferential end. That is, the movement restricting portion 532 moves circumferentially due to the elastic deformation of the elastic support portion 533 in the circumferential direction. The tip portion 532a of the movement restricting portion 532 protrudes into the insertion groove 523a. The movement restricting portion 532 has an inclined surface at the portion that the male fitting portion 513 first contacts when the male fitting portion 513 is inserted into the insertion groove 523a.

[0165] The elastic support portion 533 elastically supports the movement restricting portion 532 with respect to the bottom surface of the recess 524 of the female joint 520. The elastic support portion 533 is a member that deforms in the circumferential direction so that the movement restricting portion 532 can move in the circumferential direction. The elastic support portion 533 is made of, for example, rubber. Hereinafter, in the direction of movement of the movement restricting portion 532 elastically supported by the elastic support portion 533, the direction in which the elastic support portion 533 is compressed will be referred to as the compression direction, and the opposite direction will be referred to as the non-compression direction.

[0166] As shown in Figure 13A, when the male fitting portion 513 is inserted into the insertion groove 523a, the front end 513a of the male fitting portion 513 contacts the inclined surface of the movement restricting portion 532. As a result, as shown in Figure 13B, the elastic support portion 533 that elastically supports the movement restricting portion 532 is compressed, and the movement restricting portion 532 is housed in the recess 524. The movement restricting portion 532 pushes the male joint body portion 511 in the non-compression direction due to the restoring force of the compressed elastic support portion 533.

[0167] As shown in Figure 13C, the front end 513a of the male fitting portion 513 is moved further into the insertion groove 523a to fit the male connector 510 and the female connector 520 together.

[0168] When the male joint 510 and the female joint 520 are fitted together, the axial position of the recess 511b of the male joint body 511 and the axial position of the recess 524 of the female fitting portion 523 coincide. Therefore, when the male joint 510 and the female joint 520 are fitted together, the tip portion 532a of the movement restricting portion 532 of the circumferential movement portion 531 is housed within the recess 511b of the male joint body 511.

[0169] Therefore, the recess 511b overlaps with the movement restricting portion 532 that has moved in the non-compression direction while the male joint 510 and the female joint 520 are fitted together, when viewed in the axial direction. Furthermore, the recess 511b positions the movement restricting portion 532 that has moved in the non-compression direction while the male joint 510 and the female joint 520 are fitted together, when viewed in the axial direction, at the circumferential position where it overlaps with the recess 511b.

[0170] In other words, the recess 511b functions as both a contacted portion 541 and a circumferential positioning portion 551. Therefore, the male joint 510 is restricted from moving axially relative to the female joint 520.

[0171] As described above, in this embodiment, the circumferential moving portion 531 has a movement restricting portion 532 and an elastic support portion 533 that elastically supports the movement restricting portion 532 with respect to the female joint 520. The contacted portion 541 has a recess 511b provided in the male joint 510 so that a part of the movement restricting portion 532 can be inserted when the male joint 510 and the female joint 520 are fitted together.

[0172] Even with the axial movement restricting portion 530 having such a configuration, it is possible to prevent the pair of segments arranged in the circumferential direction from moving relative to each other in the direction opposite to the direction in which they are fitted together. That is, when the male joint 510 and the female joint 520 are fitted together, a part of the movement restricting portion 532, which is elastically supported by the elastic support portion 533 relative to the female joint 520, is inserted into the recess 511b provided in the male joint 510.

[0173] Furthermore, when the male joint 510 and female joint 520 are viewed in the axial direction, with the movement restricting portion 532 and the contacted portion 541 of the circumferential movement portion 531 overlapping, the movement restricting portion 532 contacts a part of the inner surface of the recess 511b of the male joint 10, i.e., the circumferential positioning portion 551. As a result, when viewed in the axial direction, the circumferential movement portion 531 can be positioned at a circumferential position that overlaps with the contacted portion 541, thereby more reliably preventing the circumferential movement portion 531 and the contacted portion 541 from moving relative to each other in the opposite direction to the direction in which the pair of segments are fitted together.

[0174] This allows a pair of segments aligned circumferentially in the tunnel to be connected by the segment connector 501, while preventing relative movement in the opposite direction to the fitting direction by the circumferential moving portion 531 and the contacted portion 541 of the segment connector 501. Therefore, since there is no need to provide a separate member to restrict the relative axial movement of the pair of segments, the configuration and connection structure of the pair of segments can be simplified, and a reduction in the strength of the pair of segments can be suppressed.

[0175] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0176] In each of the above embodiments, the segment connectors 1,101,201,301,401,501 connect the K segment and the B segment that constitute a cylindrical segment ring. However, the segment connectors may also connect adjacent segments that constitute a segment ring having a shape other than cylindrical.

[0177] In each of the above embodiments, the segment connectors 1, 101, 201, 301, 401, and 501 connect a K segment and a B segment. However, the segment connectors may also connect an A segment and a B segment, or adjacent A segments.

[0178] In each of the above embodiments, two segment connectors 1,101,201,301,401,501 are provided at each circumferential end of the K segment. However, one or more segment connectors may be provided at each circumferential end of the K segment.

[0179] In each of the above embodiments, the male joints 10, 210, and 510 have two anchor bars 12. However, the male joints may have one or more anchor bars.

[0180] In each of the above embodiments, the female joints 20, 320, 420, and 520 have two anchor bars 22. However, the female joints may have one or more anchor bars.

[0181] In each of the above embodiments, the two anchor bars 12 connected to the male joints 10, 210, and 510 are axial in shape. The two anchor bars 22 connected to the female joints 20, 320, 420, and 520 are axial in shape. However, the anchor bars do not have to be axial.

[0182] In each of the embodiments described above, the male joint body portions 11, 211, 511 and the anchor reinforcement bars 12 are separate components. However, the male joint body portions and the anchor reinforcement bars may be formed as a single unit.

[0183] In each of the embodiments described above, the female joint body portions 21, 321, 421, 521 and the anchor reinforcement bars 22 are separate. However, the female joint body portions and the anchor reinforcement bars may be formed as a single unit.

[0184] In each of the above embodiments, the male joint body 11 has a thickness that decreases in stages from the base end to which the anchor bar 12 is connected toward the tip 11a, and has a male fitting portion 13 at the tip 11a. That is, the thickness of the male joint body 11 excluding the male fitting portion 13 decreases in stages from the base end toward the tip. However, the thickness may gradually decrease or gradually increase from the base end toward the tip. The thickness may also be the same from the base end toward the tip. The male joint body only needs to be configured such that the thickness of the portion connected to the male fitting portion is smaller than the thickness of the male fitting portion.

[0185] In the embodiments 1, 2, and 3 described above, the circumferential movement portions 31, 331, and 431 of the axial movement restricting portions 30, 130, 230, 330, and 430 are provided on either the male or female joint so as to be located at the rear end in the direction of movement of the male joint relative to the female joint. However, the circumferential movement portions may be provided on either the male or female joint so as to be located at the front end in the direction of movement of the male joint relative to the female joint.

[0186] In embodiments 1 and 2 described above, the circumferential movement portions 31 and 331 of the axial movement restricting portions 30, 130, 230, and 330 are provided on one of the male or female joints so as to be located at the axial ends of the segment connectors 1,101, 201, and 301. However, the circumferential movement portions may be provided on one of the male or female joints so as to be located at positions other than the axial ends of the segment connectors. In this case, the other of the male or female joints should have a contact portion that, when viewed in the axial direction, overlaps with a part of the circumferential movement portion that has moved in the circumferential direction when the male and female joints are fitted together.

[0187] In the embodiments 1 and 2 described above, the contact portions 32 and 332 of the circumferentially moving portion 31 are supported by a compression coil spring 33 that expands and contracts in the circumferential direction. However, the contact portion only needs to be supported by a member that can support the contact portion so as to be movable in the circumferential direction.

[0188] In the above embodiment 4, the movement restricting portion 532 of the circumferentially moving portion 531 is supported by an elastic support portion 533 that elastically deforms in the circumferential direction. However, the movement restricting portion only needs to be supported by a member that can support the movement restricting portion so that it can move in the circumferential direction.

[0189] In the above embodiment 1, the contact portion 32 of the circumferential moving portion 31 has an inclined surface 32b that extends in a direction inclined with respect to the fitting direction, at the portion that contacts the male fitting portion 13 of the male fitting 10 when the male fitting 10 moves in the direction in which it fits with the female fitting 20. However, as shown in Figure 14, the contact portion 632 of the circumferential moving portion 631 does not have an inclined surface, and the male fitting portion 613 of the male fitting 610 may have an inclined surface 613a that extends in a direction inclined with respect to the fitting direction, at the portion that contacts the contact portion 632 when it moves in the direction in which it fits.

[0190] The male joint 610 shown in Figure 14 has a male joint body 611. The male joint body 611 has a male fitting portion 613 at its circumferential tip 611a. The front end of the male fitting portion 613 is notched. More specifically, the male fitting portion 613 has an inclined surface 613a on the front side (front side in the fitting direction) of the male joint 610 in the direction of movement of the male joint 610 relative to the female joint 20. The inclined surface 613a extends in a direction inclined with respect to the fitting direction when the male joint 610 is viewed in the thickness direction of the segment. Also, the inclined surface 613a is inclined with respect to the circumferential direction when viewed in the thickness direction.

[0191] In this configuration, the absence of an inclined surface in the contact portion 632 suppresses a decrease in the strength of the contact portion 632. Therefore, when the male joint 610 and the female joint 20 are fitted together, the contact portion 632 can more reliably restrict the movement of the male joint 610 relative to the female joint 20 in the direction opposite to the fitting direction. In addition, both the contact portion and the male fitting portion may have inclined surfaces in the parts that come into contact when moving in the fitting direction. In this case, when viewing the segment in the thickness direction, it is preferable that the length of the inclined surface of the contact portion is smaller than the length of the inclined surface of the male fitting portion.

[0192] In the second embodiment described above, the contact portion 332 of the circumferential moving portion 331 has an inclined surface 332a that extends in a direction inclined with respect to the fitting direction at the portion that contacts the opening of the insertion groove 323a of the female fitting 320 when the male fitting 10 moves in the direction in which it fits with the female fitting 320. However, the contact portion of the circumferential moving portion may not have an inclined surface, and the opening of the insertion groove of the female fitting may have an inclined surface that extends in a direction inclined with respect to the fitting direction at the portion that contacts the contact portion when it moves in the fitting direction. Both the contact portion and the opening of the insertion groove of the female fitting may each have an inclined surface at the portion that contacts them when they move in the fitting direction.

[0193] In the above embodiment 1, the axial movement restricting portion 30 has a temporary fixing portion 70. However, the axial movement restricting portion does not have to have a temporary fixing portion.

[0194] In the above embodiment 1, the temporary fixing portion 70 has a shape in which a part of it is located within the slit 23c of the insertion groove 23a and the remaining part protrudes into the insertion groove 23a. However, the temporary fixing portion only needs to have a shape that can temporarily fix the circumferentially movable portion in a predetermined position. For example, as shown in Figure 15, the temporary fixing portion 770 may have a shape in which it is sandwiched between the inner surface of the insertion groove 23a that faces the tip of the circumferentially movable portion 31 and the tip of the circumferentially movable portion 31.

[0195] In the above embodiment 1, with the male joint 10 and the female joint 20 fitted together, the temporary fixing portion 70 is located in the space S between the front end 13a and the axial end 23d of the male fitting portion 13 within the insertion groove 23a of the female fitting portion 23. However, the temporary fixing portion may be located outside the space within the insertion groove when the male and female joints are fitted together. The temporary fixing portion may not be located within the insertion groove when the male and female joints are fitted together.

[0196] In the above embodiment 1, the shape of the temporary fastening portion 70 does not change whether the contact portion 32 is temporarily fastened in a predetermined position or when the male joint 10 and female joint 20 are fitted together and move into space S. However, the shape of the temporary fastening portion may change when it moves into space. For example, the temporary fastening portion may be configured to be disassembled, divided, or otherwise separated when it moves into space. [Industrial applicability]

[0197] This invention can be used in segment connectors that connect multiple segments arranged on the excavation surface in the circumferential direction when constructing a tunnel using the shield tunneling method. [Explanation of symbols]

[0198] 1, 101, 201, 301, 401, 501 Segment Connectors 10, 210, 510, 610 Male joint 11, 211, 511, 611 Male joint body 11a, 21a, 32a, 211a, 321a, 421a, 511a, 521a, 532a, 611a Tip 12, 22 Anchor muscles 13, 213, 513, 613 Male mating part 13a, 513a front end 13b, 213b rear end 20, 320, 420, 520 female fittings 21, 321, 421, 521 Female connector body 23, 323, 423, 523 Female mating part 23a, 323a, 423a, 523a Insertion groove 23b opening 23c slit 23d Axial end 24, 324, 511b, 524 recess 30, 130, 230, 330, 430, 530 Axial movement restricting section 31, 331, 431, 531, 631 Circumferential moving part 32, 332, 632 Contact area 32b, 332a, 613a sloped surface 41, 241, 341, 441, 541 Contacted part 70, 770 Temporary fastening part 151, 251, 351, 551 Circumferential positioning section 214 Notch 334 Mounting part 424 Groove 432 Mobile Unit 432a Front end 432b Rear end 433 Head 532 Movement Control Department 533 Elastic support part

Claims

1. A pair of segments having a predetermined thickness and arranged circumferentially on the excavated surface of a tunnel, with a male joint provided at the circumferential end of one of the segments, In the other of the pair of segments, a female joint is provided at the circumferential end facing the circumferential end of the first segment, Equipped with, The male joint and the female joint are configured to fit together by the relative movement of the pair of segments in the axial direction of the tunnel, A segment connector that connects a pair of segments in the circumferential direction by fitting together the male connector and the female connector, The pair of segments are provided with an axial movement restricting section that restricts relative movement in a direction opposite to the fitting direction, The axial movement restricting unit is A circumferential moving portion is provided on either the male joint or the female joint, positioned so as to always overlap with either the male joint or the female joint when viewed in the axial direction, and so as to be movable in the circumferential direction while the movement of the segment in the thickness direction and the axial direction is restricted. The other of the male or female joint is provided with a contact portion located at a position that overlaps with the circumferentially moving portion that moves in the circumferential direction when the male and female joints are fitted together, when viewed in the axial direction, It has, The circumferential moving portion is provided on either the male or female joint so as to be located at the axial end of the segment connector, The male joint and the female joint are configured to be fitted together by the relative axial movement of the pair of segments, The circumferential moving portion is provided on either the male or female joint of the segment connector so as to be located at the rear end of the direction of movement of the male joint relative to the female joint. Segment connector.

2. In the segment connector according to claim 1, The axial movement restricting unit is The other of the male joint or the female joint is provided with a circumferential positioning unit that, when the male joint and the female joint are viewed in the axial direction, positions the circumferentially moving portion, which has moved in the circumferential direction while the male joint and the female joint are fitted together, at a circumferential position where it overlaps with the contacted portion. Segment connector.

3. In the segment connector according to claim 1, The male joint and the female joint are configured to be fitted together by the relative axial movement of the pair of segments, The contacted portion is provided on the male joint, The circumferential moving part is, The female joint has a movable body such that when the male joint contacts the front end in the direction of movement, the rear end in the direction of movement moves in the circumferential direction and approaches the male joint, When the male and female joints are viewed in the axial direction, the rear end of the movable part body moves in the circumferential direction and overlaps with the contacted part when the male and female joints are fitted together. The head portion protrudes from the rear end of the movable body in the circumferential direction, Having, Segment connector.

4. In the segment connector according to claim 1, The circumferential moving part is, Movement control section, The movement restricting portion is elastically supported by an elastic support portion that elastically supports either the male joint or the female joint, It has, The contacted portion has a recess provided in the male joint or the other female joint so that a part of the movement restricting portion can be inserted when the male joint and the female joint are fitted together. Segment connector.

5. In the segment connector according to claim 1, The circumferential moving portion and the other joint, either the male or female joint, are configured to come into contact when the pair of segments move relative to each other in the direction in which they fit together. At least one of the circumferential moving portion and the other joint has an inclined surface extending in a direction inclined with respect to the fitting direction at the portion that comes into contact with the circumferential moving portion and the other joint when they move relative to each other in the fitting direction. Segment connector.

6. A segment connecting method for connecting a pair of segments arranged in the circumferential direction of a tunnel using a segment connector having a male joint and a female joint, A temporary fixing step of temporarily fixing the circumferential moving portion of a segment connector having the configuration described in any one of claims 1 to 5 to a predetermined position in the circumferential direction of the tunnel by a temporary fixing portion, A segment assembly step in which the male joint and the female joint are moved relative to each other in the axial direction by moving the pair of segments relative to each other in the axial direction of the tunnel, A segment movement restriction step is performed to remove the temporary fastening portion by the relative axial movement of the male joint and the female joint, and to move the circumferential movement portion in the circumferential direction to bring it into contact with the contacted portion of the segment connector, Having, Segment linking method.

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