JP7736617B2 - Segment Joint - Google Patents

Description

The present invention relates to a segment joint suitable for connecting segments during shield tunnel construction.

One known segment joining structure is one in which so-called hook joints are provided as inter-segment joints between the segments to be joined, and a joint locking portion (for example, a female portion) provided on the joint surface of one of the segments is moved in the tunnel axial direction relative to a joint locking portion (for example, a male portion) provided on the joint surface of the other segment to join the segments (Patent Document 1).

Patent Document 1 discloses a female joint with two plate-shaped bases spaced apart to create a roughly C-shaped cross section, and a male joint with two plate-shaped bases closely spaced apart to create a roughly T-shaped cross section. The two bases of the male joint fit into slits in the roughly C-shaped female joint, and the locking parts of both joints lock together, connecting and joining the two segments.

Japanese Patent Application Laid-Open No. 2000-328889

In the segment joining structure described in Patent Document 1, the female joint, which is an L-shaped bend at the exposed end of the base, is prone to opening, and the joint may be joined off-center within the joint, resulting in an unstable joint.

The problem that this invention aims to solve is to prevent the female joint body from opening and to suppress misalignment by guiding it to the center position within the tunnel radial joint, thereby providing a segment joint with high construction accuracy and quality during segment assembly.

The invention of claim 1 of the present application is a segment joint comprising: a female connector having a groove formed in one direction, including a bottom, a pair of groove walls, and an opening on the segment joint surface side; and a male connector having a plate-shaped portion that protrudes from the base end on the segment joint surface side and moves along the one direction to engage with the groove portion inside the groove portion, wherein the segment joint comprises a first engaged surface that protrudes from the groove wall portion and engages with the plate-shaped portion, and a first engaging surface that protrudes from the side surface of the plate-shaped portion and engages with the first engaged surface. This segment joint is characterized in that it has an engaging portion formed thereon, the first engaged surface inclined toward the opposite side of the opening as it moves away from the groove wall portion, the first engaging surface inclined toward the base end as it moves away from the side surface of the plate-shaped portion, the first engaging portion restricting the opening of the groove wall portion, and the plate-shaped portion having a plate-shaped portion guide ridge formed to protrude from the side surface and a center guide surface provided on the plate-shaped portion guide ridge that guides the plate-shaped portion to the center inside the groove portion when it moves in the one direction.

The invention of claim 2 of the present application is the segment joint described in claim 1, characterized in that the center guide surface is formed so that its height gradually decreases along the one direction.

The invention of claim 3 of the present application is the segment joint described in claim 1 or claim 2, characterized in that the center guide surface is provided closer to the base end than the first engagement portion.

The invention of claim 4 of the present application is the segment joint described in claim 1 or claim 2, characterized in that the center guide surface is provided on the opposite side of the base end portion from the first engagement portion.

According to this invention, the first engaging portion is formed as a V-shaped inclined surface whose spacing increases toward the segment joint surface; the first engaged surface protrudes from the groove wall and engages with the plate-shaped portion; and the first engaging surface protrudes from the side of the plate-shaped portion and engages with the first engaged surface. The first engaged surface slopes toward the opposite side of the opening as it moves away from the groove wall, and the first engaging surface slopes toward the base end as it moves away from the side of the plate-shaped portion. The first engaging portion restricts the opening of the groove wall. The plate-shaped portion has a plate-shaped protrusion protruding from the side, and a center guide surface provided on the plate-shaped protrusion that guides the plate-shaped portion to the center of the interior of the groove when it moves in one direction, the segment insertion direction, i.e., the tunnel axis direction. By guiding the plate-shaped portion to the center position within the joint in the tunnel radial direction, eccentricity is reduced, resulting in the formation of a segment joint with high construction precision and high quality during segment assembly.

In addition, the center guide surface is designed to gradually decrease in height in one direction. When the male connector is inserted, the clearance narrows the further it goes, guiding the male connector to the center position inside the groove of the female connector, reducing eccentricity and enabling construction precision during segment assembly and the creation of high-quality segment joints.

1 is a schematic diagram of a shield tunnel according to a first embodiment of the present invention. FIG. FIG. 2 is a plan view of the segment according to the first embodiment of the present invention as viewed from the tunnel center side. FIG. 2 is a side view of the segment according to the first embodiment of the present invention as viewed from the tunnel axis direction. This is an enlarged view of the main parts of the female connector and male connector of the segment joint in a plan view of the segment related to the first embodiment of the present invention, viewed from the tunnel center side. 5A and 5B show a female connector and a male connector of a segment joint according to a first embodiment of the present invention, with FIG. 5A being a side view and FIG. 5B being a plan view. 1 is a perspective view of a connection state of a female connector and a male connector of a segment joint according to a first embodiment of the present invention. FIG. 1 is a side view of a segment joint according to a first embodiment of the present invention, in which a female connector and a male connector are connected together. FIG. 4A to 4C are diagrams showing a procedure for connecting segment joints of segments according to the first embodiment of the present invention. FIG. 10 is a side view of a segment joint according to a second embodiment of the present invention, in which a female connector and a male connector are connected together. 10(a) and 10(b) show a female connector and a male connector of a segment joint according to a third embodiment of the present invention, with FIG. 10(a) being a side view and FIG. 10(b) being a plan view. FIG. 10 is a perspective view of a segment joint according to a third embodiment of the present invention, showing a connection state using a female connector and a male connector. FIG. 10 is a side view of a segment joint according to a third embodiment of the present invention, in which a female connector and a male connector are connected together. FIG. 10 is a side view of a segment joint according to a fourth embodiment of the present invention, in which the segment joints are connected together. FIG. 10 is a side view of a segment joint according to a fifth embodiment of the present invention, in which a center guide surface is provided and the segments are connected. FIG. 15(b) is a cross-sectional view taken along line MM in FIG. 14, and FIG. 15(b) is a cross-sectional view corresponding to the cross-sectional view taken along line MM in FIG. 14 when there is no center guide surface. FIG. 13 is a side view of a segment joint according to a sixth embodiment of the present invention, in which a center guide surface is provided and the segments are connected.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, etc. It should be noted that the present invention is not limited to the embodiments.
The following description relates to an embodiment in which the present invention is adopted in a segment joint that connects segment pieces that are adjacent to each other in the circumferential direction of a tunnel in a shield tunnel.

First Embodiment
This embodiment uses a female joint with two plate-shaped bases arranged two apart to form an approximately C-shaped cross section, and a male joint with two plate-shaped bases arranged close together to form an approximately T-shape, and the two bases of the male joint fit into slits in the approximately C-shaped female joint and the locking parts of both joints lock together to connect and join both segments. This solves the problem that female joints with two bases arranged two apart to form an approximately C-shaped cross section are prone to opening, and the female joint is less likely to open, improving joint strength and providing a segment joint with good construction accuracy and quality when assembling the segments.

Figure 1 is a schematic diagram of a shield tunnel, Figure 2 is a plan view of the segment viewed from the tunnel center, Figure 3 is a side view of the segment viewed from the tunnel axis direction, Figure 4 is an enlarged view of the main parts of the female and male connectors of the segment joint in the plan view of the segment viewed from the tunnel center, Figure 5 shows the female and male connectors of the segment joint, Figure 5(a) is a side view, Figure 5(b) is a plan view, Figure 6 is a perspective view of the connection status using the female and male connectors of the segment joint, Figure 7 is a side view of the female and male connectors of the segment joint connected, and Figure 8 is a diagram showing the procedure for connecting the segment joints of the segments.

As shown in FIG. 1, a shield tunnel 1 is excavated underground by a shield machine that has started from the tunnel entrance, and segments 2 are assembled inside the shield machine to form a segment ring 21.
The segment ring 21 is formed by sequentially connecting pieces of each segment 2 in the tunnel circumferential direction on the face side of the existing segment ring 21.

As shown in FIGS. 2 and 3, inter-ring joints 22, which are segment joints for connecting the segment rings 21 to each other, are provided on both side surfaces of the segment 2 in the tunnel axis direction.
In this embodiment, the inter-ring joint 22 is a so-called one-pass joint made up of a male fitting and a female fitting embedded in both side surfaces of the segment 2, respectively.

As shown in Figures 2 and 3, the segment joints 3 (inter-piece joints) that connect adjacent segments 2 in the circumferential direction of the tunnel include a female connector 4 and a male connector 5, made of, for example, steel, that are installed on segment joint surfaces 20, which are both end surfaces of the segments 2 in the circumferential direction of the tunnel.
Two female connectors 4 are provided on one joint surface 20a along the tunnel axis direction, and two male connectors 5 are provided on the other joint surface 20b along the tunnel axis direction.

As shown in Figure 4, the female connector 4 and male connector 5 each have an anchor portion 6 that is embedded in the concrete that makes up the segment 2. In this embodiment, the anchor portion 6 is plate-shaped, but other anchors such as a bar-shaped anchor or a perforated steel plate anchor can also be selected as appropriate.

As shown in Figure 4, a recess 23a is provided on one of the mating surfaces 20a, and a female connector 4 is embedded adjacent to it in the tunnel axial direction. The end of the female connector 4 is provided flush with one of the mating surfaces 20a.
The male connector 5 is provided on the segment 2, protruding from the other mating surface 20b.

As shown in Figure 5, the female connector 4 has a groove 41 that includes a bottom 40, a pair of groove walls 410, 410, and an opening 42 on the segment joint surface 20 side, and is formed along one direction (from the tunnel face to the tunnel entrance in the axial direction (arrow B)).
The pair of groove walls 410, 410 are formed in parallel from an opening 42 on the segment joint surface 20 side to a bottom 40 along the approximate circumferential direction of the tunnel. An anchor portion 6 is provided on the bottom 40.

The end of the groove 41 on the tunnel face side in the tunnel axis direction is open to the recess 23a, and the end on the tunnel mouth side is not open (FIG. 5(b)).
The plate-shaped portion 51 of the male connector 5 moves in the direction from the tunnel face to the tunnel entrance (one direction (arrow B)) in the direction of the tunnel axis and engages with the groove portion 41.

Each of the pair of groove walls 410 has first groove wall protrusions 41a1 that protrude symmetrically toward the inside of the groove 41 (FIG. 5A). The surfaces of the first groove wall protrusions 41a1 facing the inside of the groove 41 are flat.
The groove wall first protrusions 41a1, 41a1 have a predetermined length along the tunnel axis direction and are formed so that their width increases symmetrically as they move from the face toward the tunnel entrance (one direction (arrow B)) (Figure 5 (b)).

The side of the groove wall first protrusion 41a1, 41a1 on the bottom 40 side is shaped to slope toward the opposite side of the segment joining surface 20 (opening 42) as it protrudes and moves away from each groove wall 410, 410, forming the first engaged surface 411, 411 (Figure 5(a)).
That is, the groove portion 41 has first engaged surfaces 411, 411 formed as V-shaped inclined surfaces that slope toward the opposite side of the opening 42 as they protrude and move away from each groove wall portion 410, 410, and the spacing between them increases toward the segment joint surface.

The side of the groove wall first protrusion 41a1, 41a1 on the opening 42 side is shaped to slope toward the segment joint surface 20 (opening 42) as it protrudes and moves away from each groove wall portion 410, 410, forming second engaged surfaces 412, 412 (Figure 5(a)).
That is, the groove portion 41 is located closer to the opening 42 than the first engaged surfaces 411, 411, and has second engaged surfaces 412, 412 formed as inverted U-shaped inclined surfaces that slope toward the opening 42 as they protrude and move away from the groove wall portions 410, 410, and the spacing between them decreases toward the segment joint surface.

As shown in Figure 5, the male connector 5 protrudes circumferentially from the base end 50 on the segment joint surface 20 side, and has a plate-shaped portion 51 that moves from the tunnel face in the axial direction toward the tunnel entrance (one direction (arrow B)) and engages with the groove portion 41 of the female connector 4 inside the groove portion 41.
The base end portion 50 is, for example, a part of the anchor portion 6, and is a portion that is embedded below the segment joining surface 20 of the plate-shaped portion 51. In this embodiment, the plate-shaped portion 51 is integrally configured to include the base end portion 50 and the anchor portion 6.

Like the groove portion 41, the plate-shaped portion 51 is also provided in a plate-like shape along the tunnel axis from the face toward the tunnel entrance (one direction (arrow B)) (Figure 5(b)).

On both radially opposite sides of the plate-like portion 51, first plate-like portion protrusions 51a1 are formed to protrude symmetrically toward the pair of groove walls 410 (FIG. 5A). The surfaces of the first plate-like portion protrusions 51a1 facing the groove walls 410 are flat.
The plate-shaped first protrusions 51a1, 51a1 have a predetermined length along the tunnel axis direction, and are arranged so that the side surface on the base end portion 50 side moves away from the segment joint surface 20 as it moves from the face toward the tunnel entrance (one direction (arrow B)) (Figure 5 (b)).

The side surface of the plate-shaped first protrusion 51a1, 51a1 on the base end portion 50 side is shaped to slope toward the base end portion 50 as it moves away from the side surface of the plate-shaped portion 51, forming first engagement surfaces 511, 511 (Figure 5 (a)).
That is, the plate-shaped portion 51 has first engagement surfaces 511, 511 that are formed as V-shaped inclined surfaces that incline toward the base end portion 50 as they protrude from the side of the plate-shaped portion 51 and move away from it, with the spacing between them increasing toward the segment joint surface.

On both radially opposite sides of the plate-like portion 51, plate-like second protrusions 51a2 are formed symmetrically toward the base end portion 50 from the plate-like first protrusions 51a1 and 51a1, respectively, toward the pair of groove walls 410 (FIG. 5(a)). The surfaces of the plate-like second protrusions 51a2 facing the groove walls 410 are flat.
The plate-shaped second protrusions 51a2, 51a2 have a predetermined length along the tunnel axis direction, and are arranged so that the side opposite the base end portion 50 approaches the segment joint surface 20 as it moves from the face toward the tunnel entrance (one direction (arrow B)) (Figure 5 (b)).

The side surface of the plate-shaped portion second protrusion 51a2, 51a2 opposite the base end portion 50 is shaped to slope toward the side opposite the base end portion 50 as it moves away from the side surface of the plate-shaped portion 51, forming second engagement surfaces 512, 512 (Figure 5 (a)).
That is, the plate-shaped portion 51 is provided with second engagement surfaces 512, 512 that are located closer to the base end 50 than the first engagement surfaces 511, 511, and that are formed as inverted U-shaped inclined surfaces that slope toward the opposite side of the base end 50 as they protrude from the side of the plate-shaped portion 51 and move away from it, with the spacing between them narrowing toward the segment joint surface.

As shown in Figures 5(b), 6, and 7, the plate-shaped portion 51 enters the recess 23a of the segment 2 that was installed earlier in the tunnel circumferential direction (arrow A), and then moves from the tunnel face toward the tunnel entrance (one direction (arrow B)) in the tunnel axial direction and enters the groove 41. As a result, the first engaging surfaces 411, 411 come into contact with the first engaging surfaces 511, 511, forming a first engaging portion 31, and the second engaging surfaces 412, 412 come into contact with the second engaging surfaces 512, 512, forming a second engaging portion 32, thereby engaging the groove 41 of the female connector 4 with the plate-shaped portion 51 of the male connector 5.

As shown in Figure 5 (b), the first engaging surfaces 411, 411 of the female connector 4 are formed so as to be gradually positioned on the opposite side of the opening 42 (towards the bottom 40) along the tunnel axial direction from the face toward the tunnel entrance (one direction (arrow B)).
In addition, the second engaging surfaces 412, 412 of the female connector 4 are formed so as to gradually move closer to the opening 42 along the tunnel axial direction from the face toward the tunnel entrance (one direction (arrow B)), i.e., so as to move away from the first engaging surfaces 411, 411 (closer to the segment joint surface 20).

As shown in Figure 5 (b), the first engagement surfaces 511, 511 of the male connector 5 are formed so as to gradually move away from the tunnel face in the tunnel axial direction toward the tunnel entrance (one direction (arrow B)) toward the opposite side of the base end 50 (so as to move away from the segment joint surface 20).
In addition, the second engagement surfaces 512, 512 of the male connector 5 are formed so as to gradually move toward the base end 50 (closer to the segment joint surface 20) along the tunnel axis from the face toward the tunnel entrance (one direction (arrow B)), i.e., so as to move away from the first engagement surfaces 511, 511 (closer to the segment joint surface 20).

FIG. 8 shows a method of connecting segments 2 equipped with female connectors 4 and male connectors 5 according to the first embodiment.
To construct a new segment ring 21 adjacent to the segment ring 21 for which construction has been completed, the segments 2 are sequentially connected in the circumferential direction of the tunnel.

To connect the segments 2, as shown in Figure 8(a), the following segment 2B is positioned so that it faces the segment 2A that was previously attached to the existing segment ring 21 with a slight gap in the tunnel circumferential direction.
At this time, the recess 23a adjacent to the female connector 4 formed on the joint surface 20a of segment 2A and the plate-shaped portion 51 of the male connector 5 formed on the joint surface 20b of segment 2B are approximately opposed to each other.

Next, as shown in Figure 8(b), the trailing segment 2B is moved circumferentially around the tunnel (in the direction of arrow A) to approach the leading segment 2A, and the plate-shaped portion 51 of the male connector 5 installed on the other joint surface 20b of segment 2B is inserted into the space in the recess 23a formed on one joint surface 20a of segment 2A.

Next, as shown in Figure 8(c), the trailing segment 2B is moved from the tunnel face toward the tunnel entrance (one direction (arrow B)) in the direction of the tunnel axis, and the first engagement surfaces 511, 511 and second engagement surfaces 512, 512 of the plate-shaped portion 51 of the male connector 5 provided on segment 2B are engaged with the first engagement surfaces 511, 511 and second engagement surfaces 512, 512 of the pair of groove wall portions 410, 410 of the female connector 4 provided on the leading segment 2A, respectively, forming first engagement portions 31, 31 and second engagement portions 32, 32 of a predetermined length in a plan view, and connecting them.

Note that providing multiple engaging portions, such as the first engaging portions 31, 31 and the second engaging portions 32, 32, may result in manufacturing and construction errors. However, sealing and cushioning materials (not shown) are provided between the joining surfaces 20a, 20b of the segments 2A, 2B, which can absorb manufacturing and construction errors.

The first engaging portions 31 are formed by first engaged surfaces 411, 411 that protrude from the groove wall portions 410, 410 and engage with the plate-shaped portion 51, and first engaging surfaces 511, 511 that protrude from the side of the plate-shaped portion 51 and engage with the first engaged surfaces 411, 411. The first engaged surfaces 411, 411 slope away from the opening 42 as they move away from the groove wall portions 410, 410, and the first engaging surfaces 511, 511 slope toward the base end 50 as they move away from the side of the plate-shaped portion 51. In other words, the first engaging portions 31, 31 form V-shaped inclined surfaces whose spacing widens toward the segment joint surface 20. The first engaging portions 31, 31 restrict the opening of the groove wall portions 410, 410, making the female connector 4 less likely to open and improving joint strength.

The second engaging portions 32, 32 are formed by second engaging surfaces 412, 412 which are located closer to the opening 42 than the first engaging surfaces 411, 411, are formed to protrude from the groove wall portions 410, 410 and engage with the plate-shaped portion 51, and second engaging surfaces 512, 512 which are located closer to the base end 50 than the first engaging surfaces 511, 511, are formed to protrude from the side surfaces of the plate-shaped portion 51 and engage with the second engaging surfaces 412, 412.The first engaging portions 31, 31 and the second engaging portions 32, 32 each restrict the opening of the groove wall portions 410, 410 at two locations, making it even more difficult for the female connector 4 to open and improving the strength of the joint.
Furthermore, by providing the second engaging portions 32, 32 in addition to the first engaging portions 31, 31 in this way, the plate-shaped portion 51 is guided to the central position between the first engaging portions 31, 31 and the second engaging portions 32, 32, and the plate-shaped portion 51 is guided to the central position in the tunnel radial direction of the groove portion 41, so that the occurrence of gaps where the engaging portions interlock is suppressed, making the female connector 4 less likely to open and stabilizing the joint strength.

The second engaged surfaces 412, 412 slope toward the opening 42 as they move away from the groove wall portions 410, 410, and the second engaging surfaces 512, 512 slope away from the base end portion 50 as they move away from the side surface of the plate-shaped portion 51. In other words, the second engaging portions 32, 32 form an inverted V-shaped slope whose spacing narrows toward the segment joint surface 20. The second engaging portions 32, 32 restrict the opening of the groove wall portions 410, 410, making it even more difficult for the female connector 4 to open. Furthermore, even if a force acts on the joint portion in the direction opposite to the pulling force (the pushing direction around the tunnel (arrow A)), the second engaged surfaces 412, 412 can withstand and counteract the force from the second engaging surfaces 512, 512. Furthermore, the slope bends the female connector 4 in the closing direction, making it even more difficult to open.

The first engaged surfaces 411, 411 are formed so that they gradually move away from the opening 42 in one direction (arrow B), and are sloped so that they gradually move away from the segment joint surface 20 in the segment insertion direction (arrow B), i.e., the tunnel axis direction. The first engaging surfaces 511, 511 are formed so that they gradually move away from the base end 50 in one direction, and are sloped so that they gradually move away from the segment joint surface in the segment insertion direction.As the segments are joined along the segment joint surface 20, the plate-shaped portion 51 of the male connector 5 is guided toward the bottom 40 of the groove 41, bringing the segment joint surfaces 20, 20 into closer contact.

In addition, the second engaged surfaces 412, 412 are formed so that they gradually move away from the first engaged surfaces 411, 411 in one direction (arrow B) and gradually move away from the first engaged surfaces 411, 411 in one direction, which is the segment insertion direction, i.e., the tunnel axis direction. The second engaging surfaces 512, 512 are formed so that they gradually move away from the first engaging surfaces 511, 511 in one direction (arrow B) and gradually move away from the first engaging surfaces 511, 511 in one direction, which is the segment insertion direction.As a result, as the segments are joined along the segment joining surfaces 20, 20, they are guided toward the center position between the first engaging portions 31, 31 and the second engaging portions 32, 32.

Second Embodiment
A second embodiment of the present invention will be described below with reference to Fig. 9. Note that a description of the same parts as in the first embodiment will be omitted, and differences will be mainly described.

In the second embodiment, the second engaged surfaces 412, 412 and the second engaging surfaces 512, 512 that constitute the second engaging portions 32, 32 are different from those in the first embodiment. This point will be described.
FIG. 9 is a side view of the segment joint 3 according to the second embodiment, in which the female connector 4 and the male connector 5 are connected.

The side surfaces of the groove wall first ridges 41a1, 41a1 of the female connector 4 on the opening 42 side rise perpendicularly from the groove wall portions 410, 410 and do not form second engaged surfaces.
In addition, the side surfaces of the groove wall first protrusions 41a1, 41a1 on the opening 42 side are arranged parallel to the tunnel axis direction from the face to the tunnel mouth (one direction (arrow B)) (not shown).

The side surfaces of the second ridges 51a2, 51a2 of the plate-like portion of the male connector 5 opposite the base end 50 rise vertically from the side surface of the plate-like portion 51 and do not form a second engagement surface.
In addition, the side surface opposite the base end portion 50 of the plate-shaped second protrusion ridges 51a2, 51a2 is arranged parallel to the tunnel axis direction from the face toward the tunnel entrance (one direction (arrow B)) (not shown).

The female connector 4 is formed with groove wall second ridges 41a2, 41a2 that protrude symmetrically from a pair of groove walls 410, 410 toward the inside of the groove 41, closer to the opening 42 than the groove wall first ridges 41a1, 41a1.
The groove wall second protrusions 41a2, 41a2 have a predetermined length along the tunnel axis direction, and the side surface of the groove wall second protrusions 41a2, 41a2 on the bottom 40 side is parallel to the side surface of the groove wall first protrusions 41a1, 41a1 on the bottom 40 side, and is formed so as to be positioned further away from the segment joint surface 20 as it moves from the tunnel face in the direction of the tunnel axis toward the tunnel mouth (one direction (arrow B)) (not shown).

The side surfaces of the second groove wall ridges 41a2, 41a2 on the bottom 40 side slope away from the opening 42 as they move away from the pair of groove wall portions 410, 410, forming second engagement surfaces 412, 412.

The male connector 5 has plate-like portion second protrusions 51a2, 51a2 formed to protrude symmetrically toward a pair of groove walls 410, 410, located closer to the base end 50 than the plate-like portion first protrusions 51a1, 51a1, and between the groove wall portion first protrusions 41a1, 41a1 and the groove wall portion second protrusions 41a2, 41a2.
The plate-shaped second protrusions 51a2, 51a2 have a predetermined length along the tunnel axis direction, and the side surface of the plate-shaped second protrusions 51a2, 51a2 on the base end 50 side is parallel to the side surface of the plate-shaped first protrusions 51a1, 51a1 on the base end 50 side, and is formed so as to be positioned away from the segment joint surface 20 as it moves from the tunnel face in the direction of the tunnel axis toward the tunnel entrance (one direction (arrow B)) (not shown).

The side surface of the plate-shaped portion second protrusions 51a2, 51a2 on the base end portion 50 side is shaped to slope toward the base end portion 50 as it moves away from the side surface of the plate-shaped portion 51, forming second engagement surfaces 512, 512.

The second engaging surfaces 412, 412 of the female connector 4 and the second engaging surfaces 512, 512 of the male connector 5 form second engaging portions 32, 32 as V-shaped inclined surfaces whose spacing widens toward the segment joint surface.

Since there are two joints, the first engagement portions 31, 31 and the second engagement portions 32, 32, the joint body is even less likely to open and can better resist tensile forces acting on the joint.

Third Embodiment
A third embodiment of the present invention will be described below with reference to Figures 10 to 12. Note that a description of the same parts as in the first and second embodiments will be omitted, and differences will be mainly described.

In the third embodiment, third engaging portions 33 are further provided on the segment joint surface 20 side of the first engaging portions 31 and the second engaging portions 32 of the first embodiment. This point will be described below.
Figure 10 shows a female connector 4 and a male connector 5, with Figure 10(a) being a side view, Figure 10(b) being a plan view, Figure 11 being an oblique view of the connection state of the female connector 4 and the male connector 5, and Figure 12 being a side view of the female connector 4 and the male connector 5 connected together.

On each of the pair of groove walls 410, 410, groove wall second ridges 41a2, 41a2 are formed to protrude symmetrically from the groove wall first ridges 41a1, 41a1 toward the opening 42 and into the groove 41 (Figure 10(a)). The surfaces of the groove wall second ridges 41a2, 41a2 facing the interior of the groove 41 are flat.

The first groove wall ridges 41a1, 41a1 and the second groove wall ridges 41a2, 41a2 are integrally connected at the rear end from the tunnel face toward the tunnel entrance in the tunnel axis direction, forming ridges 41a12, 41a12 (Figure 10(b)).

The side surface of the groove wall first protrusion 41a1, 41a1 on the bottom 40 side and the side surface of the protrusion 41a12, 41a12 on the bottom 40 side are continuous to form first engaged surfaces 411, 411 over the length L1 in the tunnel axial direction (Figure 10 (b)).
The side surfaces of the groove wall first protrusions 41a1, 41a1 on the opening 42 side form second engaged surfaces 412, 412 over a length L2 in the tunnel axial direction (FIG. 10B).

The side surface of the groove wall second protrusion 41a2, 41a2 on the bottom 40 side has a shape that slopes toward the bottom 40 as it protrudes and moves away from each groove wall 410, 410 over the length L2 in the tunnel axial direction, forming a third engaged surface 413, 413 (Figures 10(a) (b)).
That is, the groove portion 41 has third engaged surfaces 413, 413 formed as V-shaped inclined surfaces that slope toward the opposite side of the opening 42 as they protrude and move away from each groove wall portion 410, 410, and the spacing between them increases toward the segment joint surface.

The length L2 in the tunnel axis direction along which the second engaged surfaces 412, 412 and the third engaged surfaces 413, 413 are formed is set to be shorter than the length L1 in the tunnel axis direction along which the first engaged surfaces 411, 411 are formed. This is because the second engaged surfaces 412, 412 and the third engaged surfaces 413, 413 perform auxiliary engagement.

As shown in Figure 10 (b), the first engaged surfaces 411, 411 and the second engaged surfaces 412, 412 are inclined symmetrically from the tunnel face in the axial direction toward the tunnel entrance (one direction (arrow B)).
In addition, the third engaged surfaces 413, 413 are arranged parallel to the first engaged surfaces 411, 411, and are inclined symmetrically with the second engaged surfaces 412, 412 from the tunnel face in the direction of the tunnel axis toward the tunnel entrance (one direction (arrow B)).

The second plate-shaped ridges 51a2, 51a2 protruding from both side surfaces of the plate-shaped portion 51 are formed to have a length L4 in the tunnel axial direction, which is shorter than that of the first embodiment (FIG. 10(b)).
The side surfaces of the plate-shaped second ridges 51a2, 51a2 opposite the base end portion 50 form second engagement surfaces 512, 512 over a length L4 in the tunnel axial direction (FIG. 10B).

The side surface of the second protrusion 51a2, 51a2 of the plate-shaped portion on the base end 50 side has a shape that slopes toward the base end 50 as it protrudes and moves away from the side surface of the plate-shaped portion 51 over the length L4 in the tunnel axial direction, forming a third engagement surface 513, 513 (Figures 10 (a) (b)).
That is, the plate-shaped portion 51 has third engaging surfaces 413, 413 formed as V-shaped inclined surfaces that slope toward the base end portion 50 as they protrude from the side surface and move away from the side surface, with the spacing between them increasing toward the segment joint surface.

As shown in Figure 10 (b), the first engagement surfaces 511, 511 and the second engagement surfaces 512, 512 are inclined symmetrically from the tunnel face in the tunnel axis direction toward the tunnel entrance (one direction (arrow B)).
In addition, the third engagement surfaces 513, 513 are arranged parallel to the first engagement surfaces 511, 511, and are inclined symmetrically with the second engagement surfaces 512, 512 from the tunnel face in the direction of the tunnel axis toward the tunnel entrance (one direction (arrow B)).

The length L3 in the tunnel axis direction along which the first engaging surfaces 511, 511 are formed corresponds to the length L1 in the tunnel axis direction along which the first engaged surfaces 411, 411 are formed, and the length L4 in the tunnel axis direction along which the second engaging surfaces 512, 512 and the third engaging surfaces 513, 513 are formed corresponds to the length L2 in the tunnel axis direction along which the second engaged surfaces 412, 412 and the third engaged surfaces 413, 413 are formed.

As shown in Figures 10, 11, and 12, when the plate-shaped portion 51 moves from the tunnel face in the tunnel axis direction toward the tunnel entrance (one direction (arrow B)) and enters the groove portion 41, the first engaging surfaces 511, 511 engage with the first engaged surfaces 411, 411 to form the first engaging portions 31, 31, the second engaging surfaces 512, 512 engage with the second engaged surfaces 412, 412 to form the second engaging portions 32, 32, and the third engaging surfaces 513, 513 engage with the third engaged surfaces 413, 413 to form the third engaging portions 33, 33.

The third engagement surface 413, 413 is located closer to the opening 42 than the second engagement surface 412, 412, protrudes from the groove wall portion 410, 410, and engages with the plate-shaped portion 51. The third engagement surface 513, 513 is located closer to the base end 50 than the second engagement surface 512, 512, protrudes from the side surface of the plate-shaped portion 51, and engages with the third engagement surface 413, 413. As the third engagement surface 413, 413 moves away from the groove wall portion 410, 410, Therefore, it is inclined toward the opposite side of the opening 42, and the third engagement surfaces 513, 513 are inclined toward the base end 50 as they move away from the side surface of the plate-shaped portion 51. In other words, the third engagement portions 33, 33 form V-shaped inclined surfaces whose spacing increases toward the segment joint surface 20. The third engagement portions 33, 33 restrict the opening of the groove walls 410, 410. As a result, the opening of the groove walls 410, 410 of the female connector 4 is restricted in three locations, further reducing the likelihood of the joint body opening and improving joint strength.

<Fourth embodiment>
A fourth embodiment of the present invention will be described below with reference to Fig. 13. Note that a description of the same parts as those in the first to third embodiments will be omitted, and differences will be mainly described.

In the fourth embodiment, third engaging portions 33 are further provided on the segment joint surface 20 side of the first engaging portions 31 and the second engaging portions 32 of the second embodiment. This point will be described below.
FIG. 13 is a side view of the segment joint 3 with the female connector 4 and male connector 5 connected together.

The side surface of the groove wall second protrusion 41a2, 41a2 formed by protruding from a pair of groove wall portions 410, 410 into the groove portion 41 on the opening 42 side has a shape that slopes toward the segment joint surface 20 (opening 42) as it protrudes and moves away from each groove wall portion 410, 410, forming a third engaged surface 413, 413.
That is, the groove portion 41 is located closer to the opening 42 than the second engaged surfaces 412, 412, and has third engaged surfaces 413, 413 formed as inverted U-shaped inclined surfaces that slope toward the opening 42 as they protrude and move away from the groove wall portions 410, 410, and the spacing between them decreases toward the segment joint surface.

Although not shown, the first engaged surfaces 411, 411 and the second engaged surfaces 412, 412 are arranged parallel to each other in the direction from the tunnel face toward the tunnel entrance (one direction (arrow B)) in the direction of the tunnel axis. Furthermore, the third engaged surfaces 413, 413 are inclined symmetrically with the second engaged surfaces 412, 412 in the direction from the tunnel face toward the tunnel entrance (one direction (arrow B)) in the direction of the tunnel axis.

On both radially opposite sides of the plate-like portion 51, plate-like portion third protrusions 51a3 are formed to protrude symmetrically toward the pair of groove walls 410, respectively, so as to be located closer to the base end portion 50 than the plate-like portion second protrusions 51a2, and closer to the segment joint surface 20 than the groove wall second protrusions 41a2. The surfaces of the plate-like portion third protrusions 51a3, 51a3 facing the groove walls 410, 410 are flat.
The plate-shaped third protrusions 51a3, 51a3 have a predetermined length along the tunnel axis direction, and are arranged so that the side opposite the base end portion 50 approaches the segment joint surface 20 as it moves from the face toward the tunnel entrance (one direction (arrow B)) (not shown).

The side surfaces of the plate-shaped third protrusions 51a3, 51a3 opposite the base end 50 are inclined toward the side opposite the base end 50 as they move away from the side surface of the plate-shaped portion 51, forming third engagement surfaces 513, 513.
That is, the plate-shaped portion 51 is provided with third engagement surfaces 513, 513 which are located closer to the base end 50 than the second engagement surfaces 512, 512, and which are formed as inverted U-shaped inclined surfaces which incline toward the opposite side of the base end 50 as they protrude from the side of the plate-shaped portion 51 and move away from it, with the spacing between them narrowing toward the segment joint surface.

Although not shown, the first engagement surfaces 511, 511 and the second engagement surfaces 512, 512 are arranged parallel to each other in the direction from the tunnel face to the tunnel entrance (one direction (arrow B)) in the direction of the tunnel axis. Furthermore, the third engagement surfaces 513, 513 are inclined symmetrically with the second engagement surfaces 512, 512 in the direction from the tunnel face to the tunnel entrance (one direction (arrow B)) in the direction of the tunnel axis.

When the plate-shaped portion 51 moves from the tunnel face in the direction of the tunnel axis toward the tunnel entrance (one direction) and enters the interior of the groove portion 41, the first engaging surfaces 511, 511 engage with the first engaged surfaces 411, 411 to form the first engaging portions 31, 31, the second engaging surfaces 512, 512 engage with the second engaged surfaces 412, 412 to form the second engaging portions 32, 32, and the third engaging surfaces 513, 513 engage with the third engaged surfaces 413, 413 to form the third engaging portions 33, 33.

The third engagement surface 413, 413 is located closer to the opening 42 than the second engagement surface 412, 412, protrudes from the groove wall portion 410, 410, and engages with the plate-shaped portion 51. The third engagement surface 513, 513 is located closer to the base end 50 than the second engagement surface 512, 512, protrudes from the side surface of the plate-shaped portion 51, and engages with the third engagement surface 413, 413. As the third engagement surface 413, 413 moves away from the groove wall portion 410, 410, Therefore, it is inclined toward the opening 42, and the third engagement surfaces 513, 513 are inclined toward the opposite side of the base end 50 as they move away from the side of the plate-shaped portion 51. In other words, the third engagement portions 33, 33 form an inverted V-shaped inclined surface whose spacing decreases toward the segment joint surface 20. The third engagement portions 33, 33 restrict the opening of the groove wall portions 410, 410. As a result, the opening of the groove wall portions 410, 410 of the female connector 4 is restricted in three locations, making the joint less likely to open and improving joint strength.

Fifth Embodiment
Hereinafter, a fifth embodiment of the present invention will be described with reference to Figures 14 and 15. Note that a description of the same parts as those in the first to fourth embodiments will be omitted, and the following mainly describes the different parts.

This embodiment solves the problem of female joints easily opening, as in the first embodiment, and also suppresses misalignment by guiding them to the center position within the tunnel radial joint, providing high-quality segment joints with high construction accuracy during segment assembly.

Figure 14 is a side view of the segment joint with the female and male connectors connected, Figure 15(a) shows the connection procedure, with the right side being an M-M cross section in Figure 14, and Figure 15(b) shows the connection procedure when there is no center guide surface, with the right side being a diagram equivalent to the M-M cross section in Figure 14.

The first engaged surfaces 411, 411 formed on the groove wall first ridges 41a1, 41a1 of the female connector 4 and the first engaging surfaces 511, 511 formed on the plate-like first ridges 51a1, 51a1 of the male connector 5, similar to the first embodiment, form the first engaging portions 31, 31 as V-shaped inclined surfaces whose spacing widens toward the segment joint surface, thereby restricting the opening of the groove wall portions 410, 410.

The side surfaces of the groove wall first ridges 41a1, 41a1 of the female connector 4 on the opening 42 side rise perpendicularly from the groove wall portions 410, 410 and do not form second engaged surfaces.
In addition, the side surfaces of the groove wall first protrusions 41a1, 41a1 on the opening 42 side are arranged parallel to the tunnel axis direction from the face to the tunnel mouth (one direction (arrow B)) (not shown).

On both radially opposite sides of the plate-shaped portion 51, plate-shaped portion guide protrusions 51b, 51b are formed symmetrically protruding toward each of a pair of groove wall portions 410, 410, closer to the base end portion 50 than the plate-shaped portion first protrusions 51a1, 51a1 and positioned on the opening 42 side of the groove wall portion first protrusions 41a1, 41a1.
The plate-shaped portion guide protrusions 51b, 51b are formed with a predetermined length parallel to the tunnel axis direction, and the side surface on the base end portion 50 side and the side surface opposite the base end portion 50 rise vertically from the side surface of the plate-shaped portion 51.

The plate-shaped guide ridges 51b, 51b are provided with center guide surfaces 51b1, 51b1 on the surfaces facing the groove walls 410, 410, respectively.
As shown in FIG. 14, the center guide surfaces 51b1, 51b1 are surfaces parallel to the circumferential direction of the tunnel, and as shown in FIG. 15(a), they are inclined so that the height of the plate-shaped guide ridges 51b, 51b gradually decreases from the tunnel face in the axial direction toward the tunnel entrance (in one direction (arrow B)).

The highest portions of the center guide surfaces 51b1, 51b1 are set higher than the height of the plate-shaped first ridges 51a1, 51a1 (FIG. 14).
The center guide surfaces 51b1, 51b1 are provided closer to the base end 50 of the plate-shaped portion 51 than the first engagement portions 31, 31.

As shown in Figure 15(a), when the male connector 5 is moved in one direction (arrow B) from the tunnel face in the axial direction toward the tunnel entrance and inserted into the groove 41 of the female connector 4, the clearance between the plate-shaped guide ridges 51b, 51b and the groove walls 410, 410 gradually narrows as it enters. In other words, by guiding the male connector 5 to the center position inside the groove 41 of the female connector 4 (the center position in the radial direction of the tunnel), the amount of eccentricity (misalignment) is suppressed, and the first engaged surfaces 411, 411 and the first engaging surfaces 511, 511 are engaged at their central positions, more reliably preventing the groove walls 410, 410 from opening, resulting in the formation of a segment joint with high construction accuracy and high quality during segment assembly.

FIG. 15(b) is a side view of a male connector 5 without plate-like portion guide ridges 51b, 51b inserted in the tunnel axial direction and connected to a female connector 4.
In such a case, when the male connector 5 penetrates into the female connector 4, a large eccentricity T occurs between the male connector 5 and the center position inside the groove portion 41 of the female connector 4, causing the clearance to become biased, and the first engaged surfaces 411, 411 and the first engaging surfaces 511, 511 engage away from the center position, making it unstable to prevent the groove wall portions 410, 410 from opening.

Sixth Embodiment
A sixth embodiment of the present invention will be described below with reference to Fig. 16. Note that a description of the same parts as those in the first to fifth embodiments will be omitted, and differences will be mainly described.

In this embodiment, the center guide surfaces 51b1, 51b1 of the fifth embodiment are provided on the plate-shaped first protrusions 51a1, 51a1. The plate-shaped first protrusions 51a1, 51a1 also function as plate-shaped guide protrusions 51b, 51b.
FIG. 16 is a side view of the female connector and male connector of the segment joint connected together.

The plate-shaped first ridges 51a1, 51a1 (plate-shaped guide ridges 51b, 51b) have center guide surfaces 51b1, 51b1 on the surfaces facing the groove walls 410, 410, respectively.
The center guide surfaces 51b1, 51b1, like the center guide surfaces 51b1, 51b1 of the fifth embodiment, are surfaces parallel to the circumferential direction of the tunnel and are inclined so that the height of the plate-shaped portion first protrusions 51a1, 51a1 (plate-shaped portion guide protrusions 51b, 51b) gradually decreases from the tunnel face in the axial direction toward the tunnel entrance (one direction (arrow B)).

The center guide surfaces 51 b 1 , 51 b 1 are provided on the opposite side of the base end portion 50 of the plate-shaped portion 51 from the first engagement portions 31 , 31 .
In this embodiment, the plate-shaped portion first protrusions 51a1, 51a1 are given the function of plate-shaped portion guide protrusions 51b, 51b, so there is no need to provide separate plate-shaped portion guide protrusions 51b, 51b, and a simple structure can be formed.

[Other Modifications]
The present invention is not limited to the above-described embodiment, and may also include the following, for example.

In this embodiment, the present invention is adopted in a segment joint that connects segment pieces adjacent to each other in the tunnel circumferential direction, but is not limited to this and can also be adopted in a segment joint that is an inter-ring joint.
Furthermore, the present invention is not limited to coupling joints that move in the tunnel axial direction, but may also be applied to coupling joints that move in the tunnel radial direction, in which case the tunnel radial direction corresponds to one direction in the present invention.

In the first to fourth embodiments, multiple engagement portions were provided to restrict the opening of the groove wall portion, but it may also be configured with only the first engagement portion.

The technical aspects of any embodiment may be applied to other embodiments to create examples.

For example, the plate-shaped portion guide ridges 51b having the center guide surfaces 51b1, 51b1 of the fifth embodiment may be further provided closer to the base end portion 50 than the plate-shaped portion second ridges 51a2, 51a2 of the first embodiment.
Furthermore, for example, the plate-shaped third ridges 51a3, 51a3 of the second embodiment may be given the function of the plate-shaped guide ridges 51b, 51b having the center guide surfaces 51b1, 51b1.

DESCRIPTION OF SYMBOLS 1 Shield tunnel 2 Segment 20 Segment joint surface 20a One joint surface 20b Other joint surface 21 Segment ring 22 Inter-ring joint 23a Recessed portion 3 Segment joint 31 First engaging portion 32 Second engaging portion 33 Third engaging portion 4 Female connector 40 Bottom portion 41 Groove portion 410 Groove wall portion 411 First engaged surface 412 Second engaged surface 413 Third engaged surface 41a1 Groove wall portion first protrusion 41a2 Groove wall portion second protrusion 42 Opening on segment joint surface side 5 Male connector 50 Base end portion 51 Plate-shaped portion 511 First engaging surface 512 Second engaging surface 513 Third engaging surface 51a Plate-shaped portion protrusion 51a1 Plate-shaped portion first protrusion 51a2 Plate-shaped portion second protrusion 51a3 Plate-shaped portion third protrusion 51b Plate-shaped portion guide protrusion 51b1 Center guide surface 6 Anchor portion

Claims (4)

A segment joint comprising: a female connector having a groove formed in one direction, the female connector including a bottom, a pair of groove walls, and an opening on the segment joint surface side; and a male connector having a plate-like portion that protrudes from a base end on the segment joint surface side and moves along the one direction to engage with the groove inside the groove,
a first engaged surface formed to protrude from the groove wall portion and engage with the plate-shaped portion;
a first engaging surface formed to protrude from a side surface of the plate-shaped portion and to engage with the first engaged surface,
the first engaged surface is inclined toward the opposite side of the opening as it moves away from the groove wall portion,
the first engagement surface is inclined toward the base end portion as it moves away from the side surface of the plate-shaped portion,
the first engagement portion restricts the opening of the groove wall portion,
a plate-shaped portion guide ridge formed to protrude from a side surface; and a center guide surface provided on the plate-shaped portion guide ridge that guides the plate-shaped portion to the center inside the groove portion when the plate-shaped portion moves in the one direction. A segment joint as described in claim 1, characterized in that the center guide surface is formed so that its height gradually decreases along the one direction. The segment joint according to claim 1 or 2, wherein the center guide surface is provided closer to the base end portion than the first engagement portion. The segment joint according to claim 1 or 2, wherein the center guide surface is provided on the opposite side of the base end portion from the first engagement portion.