JP4888724B2 - Joint structure and segment including the same - Google Patents

Description

  The present invention relates to a joint structure used for a tunnel constructed by a shield method, for example, and a segment including the joint structure.

Conventionally, a steel (steel) segment is often used as a segment used in a shield method, for example, in a small-section tunnel such as a water and sewage system. The steel segment has a plate-like frame formed from an arcuate plate-shaped steel skin plate and a girder member arranged at the outer edge of the steel plate, and a number of reinforcing ribs are placed inside the plate-like frame. It has been done.
Furthermore, in recent years, a steel plate segment mainly composed of an arc plate skin plate has been proposed by reducing the amount of use of the beam members and reinforcing ribs of the steel segment (see, for example, Patent Documents 1 and 2).

Patent Document 1 is provided with a base segment provided with a concrete lining body on the inner peripheral surface of a steel plate in a tunnel base, and a steel plate segment is joined above the base segment to form a ring shape. It describes a structure in which a rib joint in which a bolt hole is formed at the joining end portion projects from the inner peripheral surface of the segment, and the segments are joined together by a bolt.
Patent document 2 consists of a cylindrical steel plate (steel pipe), and regulates the connecting end of the segment so that it does not shift in the tunnel radial direction, and a regulating member capable of joining adjacent segments with a bolt. It describes the segment protruding from the inner peripheral surface.
JP 2002-276298 A Japanese Patent No. 3154476

However, the segment using the conventional steel plate as the outer shell plate has the following problems.
That is, the segments made of steel sheets of Patent Documents 1 and 2 have a structure in which the thickness dimensions of the segments are made substantially the same as the thickness dimensions of the steel sheets by reducing the number of joints, girders, and reinforcing ribs. Because the joint rib with bolt holes for bolt fastening protrudes from the inner peripheral surface of the steel plate to the inside of the well, the outer diameter dimension of the segment, that is, the outer diameter of the tunnel excavation, It was necessary to set so as not to invade. For this reason, there is a limit to reducing the outer diameter of the segment, and it is required to further reduce the amount of protrusion of the joint and the reinforcing part to the inner space of the tunnel, leaving room for improvement in that respect.
Moreover, in patent document 1, although it is set as the structure which reduced the quantity of the joint by bolt fastening in the segment of 1 ring, since the bolt joining location is not lost, the joining operation | work by a bolt is required, and the work is troublesome. Since it takes time, further improvement in work efficiency is required.

The present invention has been made in view of the above-described problems, and by reducing the thickness of an article such as a segment by reducing the thickness, a joint structure and a segment including the joint structure are provided. The purpose is to provide.
Another object of the present invention is to provide a joint structure that improves the efficiency of assembly work of articles such as segments, and a segment including the same, by using a simple joining structure.

In order to achieve the above object, in the joint structure according to the present invention, an article composed of a male joint attached to the surface of one article and a male joint attached to the surface of the other article is brought into contact with each other. The male joint has a thin plate shape, and the width of the thin plate gradually increases toward the inner side in the thickness direction of the product on the side of the thin plate. The female joint has a notch shape that engages with the male joint, and a second taper in which the notch width dimension gradually increases toward the inside in the thickness direction of the article on the side surface of the notch. It is characterized in that a surface is formed.
Further, in the segment having the joint structure according to the present invention, the above-described article is a segment, and the male joint and the female joint are disposed on the inner surface side of the segment and attached to the joint surface side between the rings. It is characterized by having.

  In the present invention, since the first taper surface of the male joint and the second taper surface of the female joint are engaged, the male joint is detached from the female joint and the outer side in the thickness direction of the article such as a segment. The articles can be firmly joined to each other on the joining surface side. And since these male joints and female joints are thin plate-shaped, the thickness dimension of articles | goods itself can be made small and size reduction can be achieved. For example, when the article is a segment, by reducing the thickness of the segment, the outer diameter of the segment installed in the tunnel is reduced, and the cost of the segment can be reduced.

  Moreover, in the segment provided with the joint structure according to the present invention, the male joint may protrude from the joint surface between the rings.

Moreover, in the segment provided with the joint structure according to the present invention, the male joint may have a shape divided into two in the circumferential direction on the joint surface in the tunnel circumferential direction.
Moreover, in the segment provided with the joint structure according to the present invention, the female joint may have a shape divided into two in the circumferential direction on the joint surface in the tunnel circumferential direction.

  In the present invention, when the joint surfaces in the tunnel circumferential direction (between pieces) of both segments adjacent to each other in the circumferential direction are brought into contact with each other, the joint divided into two is in a state of continuously contacting in the circumferential direction. It is possible to join adjacent segments between pieces by engaging two joints in a state where the joints that are not divided into two parts of the adjacent segments in the tunnel axial direction (inter-ring direction) are engaged. it can. As described above, since the male joint and the female joint provided on the joint surface between the rings are engaged with each other, the segments can be joined between the rings and the pieces. Efficiency can be improved and the construction period can be shortened.

  Further, in the segment having the joint structure according to the present invention, the segment is an outer shell plate formed in an arc plate shape, and an inner plate shape forming a thin plate shape provided along the inner peripheral surface of the outer shell plate. It is preferable that the male joint and the female joint are respectively attached to the inner peripheral surface side of the outer shell plate and are flush with the inner peripheral surface of the inner plate-shaped portion.

  In the present invention, the male joint and the female joint have a thin flat plate shape, and the thickness of the segment can be reduced by attaching these joints to the inner peripheral surface of the outer shell plate. Furthermore, by forming the segment inner peripheral surface so as to be flush with the inner peripheral surface of the male joint and the female joint, the inner peripheral surface of the segment assembled in a ring shape in the tunnel peripheral direction has no protrusions. It can be a smooth surface. Since the inner peripheral surface can be made smooth with such a thin wall, the outer diameter of the segment can be reduced while reliably ensuring the cross section in the tunnel, and the cost of the segment can be reduced.

According to the joint structure of the present invention and the segment including the same, it is possible to reduce the size of the article such as the segment as a thin wall. For example, when the article is a segment, the diameter of the segment can be reduced. As a result, the cost of the segment itself can be reduced, the tunnel excavation section can be made smaller, the diameter of the shield excavator can be reduced, and the cost can be reduced. Disposal costs can be reduced.
In addition, since the male joint provided on the surface of the articles such as segments, the female joint is simply inserted and fitted together, it becomes a simple joint structure that can firmly join the articles, The joining operation can be simplified, and the efficiency of the article assembly operation can be improved.

Hereinafter, a joint structure according to a first embodiment of the present invention and a segment including the joint structure will be described with reference to FIGS. 1 to 8.
1 is a perspective view of a segment according to the first embodiment of the present invention, FIG. 2 is a perspective view showing a joined state of the segments, FIG. 3 is a partially broken enlarged view of the segment shown in FIG. 2, and FIG. FIG. 5 is a plan view showing the segment, FIG. 6 is a side view of the segment, (a) is a view showing the male joint, and (b) is a female type. FIG. 7 is a view showing a joint, FIG. 7 is a view showing a state where a segment is transported in the vicinity of a subsequent facility, and FIG. 8 is a side view showing a configuration of a shield jack.

As shown in FIG. 1, the segment 1 (article) according to the first embodiment is a shield having a relatively small cross section (for example, 3 m or less in tunnel outer diameter) used for, for example, water and sewage and communication lines. Tunnel lining that is a thin arc plate-shaped segment that is applied to tunnels, etc., and is arranged by connecting multiple circumferentially and axially along the inner wall surface of the tunnel excavated in a circular section. It builds the body.
In the following description of the joining of the segments 1, the segments adjacent in the tunnel axis direction are collectively used as “between rings” and the segments adjacent in the tunnel circumferential direction are used as “between pieces”.

Segment 1 (1A, 1B, 1C) is obtained by dividing the ring shape arranged along the inner circumferential surface of the tunnel into three equal parts in the tunnel circumferential direction.
As shown in FIG. 2, the segments 1 </ b> A, 1 </ b> B, and 1 </ b> C are joined to adjacent ends in the tunnel axis direction at both ends in the tunnel axis direction (ends between the rings, the long side of the segment 1). Inter-ring joint surfaces 1a and 1b (reference numeral 1a is a first inter-ring joint surface and reference numeral 1b is a second inter-ring joint surface). Further, at both ends in the tunnel circumferential direction (end between the pieces, the short side of the segment 1), there are inter-piece joint surfaces 1c and 1d that join adjacent ones in the tunnel circumferential direction. The positions of the inter-piece joint surfaces 1c and 1d between the adjacent segment rings are shifted by about half the length of the longitudinal dimension of the segment 1 in the tunnel circumferential direction.

  The segments 1A, 1B, and 1C include a skin plate 2 (outer shell plate) that is curved along the circumferential direction of the tunnel, and a coating coating portion 3 (inner plate-like portion) that is provided along the inner peripheral surface 2a of the skin plate 2. ), And a male joint 10 and a female joint 20 for joining the segments 1 and 1 between the rings and between the pieces.

  As shown in FIG. 3, the coating portion 3 is formed by coating a resin material or the like with a predetermined thickness along the inner peripheral surface 2 a of the skin plate 2. Specifically, it is the same dimension as the thickness dimension of the male joint 10 and the female joint 20, and the position of the inner peripheral surface 3 a of the coated coating portion 3 is the inner peripheral surface of the male and female joints 10, 20. 10a and 20a are provided so as to be flush with each other. That is, the male joint 10 and the female joint 20 are attached to the inner peripheral surface 2a of the skin plate 2 so as to be flush with the inner peripheral surface 3a of the coating portion. In other words, on the joint surface side of the segment 1 composed of the skin plate 2 and the coating portion 3, the surface of the segment is exposed and attached to the inner surface of the segment.

  As shown in FIG. 2, in the first embodiment, the male joint 10 is provided on the side of the first inter-ring joint surface 1a to be connected to the segment 1, and the other second to be connected. A female joint 20 is provided on the inter-ring joint surface 1b side.

  As shown in FIGS. 4, 5, and 6 (a), the male joint 10 protrudes in the direction (tunnel axis direction) orthogonal to the first inter-ring joint surface 1 a, and the plane side thereof in the segment 1. It has a flat plate shape facing the inner peripheral surface or the outer peripheral surface. And the inner peripheral surface 10a of the male joint 10 is flush with the inner peripheral surface of the segment 1 (the inner peripheral surface 3a of the coating portion 3), that is, both inner peripheral surfaces 10a and 3a are continuous and have a smooth surface. It is provided to be formed.

  The male joint 10 includes a first male joint 10A that is integrally formed and a second male joint 10B that is formed by dividing the first male joint 10A into two parts in the tunnel circumferential direction. The first male joint 10A is disposed substantially at the center in the circumferential direction of the first inter-ring joint surface 1a, and the second male joint 10B is disposed at both circumferential ends of the first inter-ring joint surface 1a (inter-piece joint surface 1c, 1d and the same position). The male joint 10 has one surface fixed to the inner peripheral surface of the skin plate 2 and the other surface exposed to the inner peripheral surface of the segment 1 so as to be embedded in the inner plate-shaped portion 3. Has been integrated.

Further, the male joint 10 (10A, 10B) has a tip formed so as to be chamfered obliquely so that the width dimension (length dimension along the longitudinal direction of the segment) is tapered toward the tip side at the tip corner portion. The direction in which the width of the thin plate gradually increases from the inner peripheral surface of the segment 1 toward the outer peripheral surface in the thickness direction (as it goes inward in the thickness direction of the segment 1) on the side surface of the tapered portion 11a and the male joint 10 And a male taper surface 11b (first taper surface) that is inclined to the surface.
The thickness dimension of the male joint 10 is approximately the same as that of the coating portion 3.

On the other hand, as shown in FIGS. 3, 4, 5, and 6 (b), the female joint 20 is disposed at a position facing each of the first and second male joints 10 </ b> A and 10 </ b> B in the segment 1. The first female joint 20A and the second female joint 20B are made engageable by inserting them. That is, the female joint 20 has a notch shape that is open at the position of the second inter-ring joint surface 1 b, and is formed with a recess 21 that is substantially the same shape as the male joint 10. One end face is fixed to the inner peripheral face 2a of the skin plate 2, and the other end face (inner peripheral face 20a) is flush with the inner peripheral face 3a of the coating portion 3, that is, both inner peripheral faces 20a. 3a are provided so that a smooth surface is continuously formed.
The female joint 20 has one surface fixed to the inner peripheral surface 2a (see FIG. 3) of the skin plate 2 and the other surface exposed to the inner peripheral surface of the segment 1 flush with the inner plate-shaped portion. 3 is embedded in a single structure.

  The concave portion 21 is formed on the side surface extending in the tunnel axis direction from the inner peripheral surface toward the outer peripheral surface (as it goes inward in the thickness direction of the segment 1). Female side taper surface 21a (second taper surface) that is inclined in the direction in which the length dimension (corresponding to the notch width dimension of the present invention) increases and engages with the male side taper surface 11b of the male joint 10. Is formed. That is, the male joint 10 inserted and engaged with the female joint 20 is engaged with the tapered surfaces 11b and 21a formed on the side surfaces so as to be sandwiched from the side surfaces. The inner joint surfaces 10a and 20a of both the mold joints 20 are kept from being flush with each other without protruding from the inner joint surface of the male joint 10 so that the male joint 10 is segmented from the female joint 20. It is comprised so that it may not slip out inside 1.

  And the segment ring which comprises a cylindrical wall body is constructed | assembled by joining 10A of male joints and female joint 20A of these segments 1 and 1 arrange | positioned adjacent to the axial direction (between rings) of a tunnel. become.

Next, the effect | action of the joint structure of a segment by such a structure and the joining method of a segment are demonstrated.
As shown in FIG. 2 and FIG. 4, the segment ring segments 1 and 1 (denoted by reference numerals 1A and 1B in the description) of the segment ring assembled in advance are compared with the recesses 21 of the female joints 20A and 20B. The positions of the first and second inter-ring joint surfaces 1a and 1b are aligned so that the convex portions 11 of the male joints 10A and 10B of the segment 1A ′ on the assembly side of the segment ring face each other.

  Further, the first inter-ring joint surface 1a is brought close to the second inter-ring joint surface 1b in the direction of arrow E shown in FIGS. The segments 1A ′, 1A, 1B are joined together. At this time, the male side taper surface 11b of the male joint 10 is guided and inserted into the female side taper surface 21a of the female joint 20. Since the male joint 10 has a tip tapered portion 11a, even if the convex portion 11 is inserted with a slight shift in the circumferential direction with respect to the concave portion 21, it is guided to the tip tapered portion 11a. And will be inserted into the recess 21.

More specifically, when the inter-piece joining surfaces 1c and 1d of both segments 1A and 1B adjacent in the circumferential direction are brought into contact with each other, the second female joints 20B and 20B that are divided into two are arranged in the circumferential direction. The first male joint 10A (integrated joint) in which the segment 1A 'adjacent in the tunnel axis direction is integrally formed with the two second female joints 20B and 20B in this state. By inserting and engaging, the segments 1A and 1B between the pieces can also be joined.
In this way, by joining the male joint 10 and the female joint 20 provided on the inter-ring joint surfaces 1a and 1b, the segments 1, 1 are joined between the rings and the pieces. Therefore, the efficiency of the assembly work of the segment 1 is improved, and the construction period can be shortened.

  Then, after assembling the segment 1A ′, the segment 1B ′ (see FIG. 4) adjacent to one circumferential direction (inter-piece direction) side of the assembled segment 1A ′ is assembled. Thus, by sequentially joining the three segments 1A, 1B, 1C (see FIG. 1) on the same circumference of the inner wall surface of the excavated tunnel, a ring-shaped segment ring body is constructed at that portion. become. And by joining such segment ring bodies continuously in the excavation direction, the entire inner surface of the excavated portion is covered with a plurality of segments 1, 1,.

Moreover, since the male side taper surface 11b of the male joint 10 and the female side taper surface 21a of the female joint 20 are engaged, the convex part 11 comes off the concave part 21 and comes out to the inner peripheral side of the segment 1. Therefore, a strong joint structure can be obtained.
As described above, the male joint 10 and the female joint 20 have a thin flat plate shape, and the joints 10 and 20 are provided on the inner peripheral surface 2a of the skin plate 2, thereby reducing the thickness of the segment 1. Can be thinned. Further, by forming the segment inner peripheral surface so as to be flush with the inner peripheral surfaces of the male joint 10 and the female joint 20, the inner peripheral surface of the segment 1 assembled in a ring shape in the tunnel peripheral direction is projected. It is possible to make the surface smooth. Since the inner peripheral surface can be made smooth with such a thin wall, the outer diameter of the segment can be reduced while reliably ensuring a hollow section in the tunnel, and the manufacturing cost of the segment 1 can be reduced. it can.

  And in this segment 1, highly accurate positioning is unnecessary like the joint which uses a bolt and a nut, and the convex part 11 of the male joint 10 (10A, 10B) is made into the female joint 20 (20A, 20B). It has a simple joint structure in which the segments 1, 1 adjacent to each other between the rings and the pieces can be joined by a simple method of only inserting into the recess 21.

Next, the transport method in the mine when assembling the segment 1 and the propulsion direction will be described with reference to the drawings.
As shown in FIG. 7, as a method of transporting the segment 1 in the mine, the transport cart 32 is in a state in which the segment 1 is erected so that the segment 1 can pass next to a subsequent facility 31 disposed behind a shield excavator (not shown). It is set as the structure made to mount and convey. At this time, it is supported on the carriage 32 by a fixing means (not shown). And although not shown in particular, in the section having only the rails without the trailing carriage 31, the horizontal central portion of the pit cross section can be passed. And in the installation section of the succeeding carriage 31, since it passes through the side of the cross section of the mine, the upper end of the segment 1 to be transported with the existing segment 1 so that the segment 1 to be transported does not hit the wall surface of the existing segment 1 A roller 33 is provided therebetween.
As described above, since the segment 1 is thin and the joints do not protrude to the inner peripheral surface side of the segment 1, the space in the mine can be used effectively even during transportation, particularly as shown in FIG. In such an installation section of the succeeding carriage 31, the width dimension of the succeeding carriage 31 can be increased, and equipment can be efficiently arranged on the succeeding carriage 31.

  Further, as shown in FIG. 8, when the segment 1 is used, a shield excavator (not shown) is propelled by the jack tip (spreader 35) of the shield jack 34 provided at the rear end of the shield excavator. A notch groove 35a is formed in the rear end surface, and the reaction force is taken from the segment 1 in a state where the notch groove 35a is fitted to the face end portion of the assembled segment 1 (that is, the second inter-ring joint surface 1b). This is a method of propelling by a configuration in which the shield jack 34 is extended.

As described above, in the joint structure according to the first embodiment and the segment including the joint structure, the segment 1 can be made thin and the diameter can be reduced. As a result, the cost of the segment itself can be reduced, the tunnel excavation section can be made smaller, the diameter of the shield excavator can be reduced, and the cost can be reduced. Disposal costs can be reduced.
Further, the segments 1 and 1 can be firmly joined to each other simply by inserting and fitting the male joint 10 and the female joint 20 provided on the inter-ring joining surfaces 1a and 1b side of the segment 1. Since it can be a simple joint structure, the joining operation can be simplified, and the efficiency of the assembling operation of the articles can be improved.

Next, a second embodiment of the present invention will be described with reference to FIGS. 9 and 10, but the same or similar members and parts as those of the above-described embodiment will be denoted by the same reference numerals and description thereof will be omitted. A configuration different from that of the embodiment will be described.
FIG. 9 is a diagram showing the joining state of the segments according to the second embodiment of the present invention, which corresponds to FIG. 4, and FIG. 10 is a plan view of the segments shown in FIG.
As shown in FIGS. 9 and 10, the segment 4 of the second embodiment has a configuration in which the arrangement of the male joint 10 and the female joint 20 in the first embodiment is changed. That is, in the first embodiment shown in FIG. 5, the male joint 10 (10A, 10B) is arranged on the first inter-ring joint surface 1a side, and the female joint 20 (20A on the second inter-ring joint surface 1b side). 20B), but in the second embodiment in FIG. The male joints 10 and the female joints 20 are alternately arranged along the circumferential direction on both the first and second inter-ring joint surfaces 4a and 4b.

Specifically, in this segment 4, a male joint 10 is provided so as to be flush with the piece-to-piece joint surfaces 4c and 4d along both circumferential ends of the joint surfaces 4a and 4b between the rings. 10, the second male joint 10B divided into two in the tunnel circumferential direction as described above is disposed. A female joint 20 is provided at a substantially central portion in the circumferential direction on the side of the joint surfaces 4a and 4b between the rings, and the female joint 20 has a configuration in which the first female joint 20A forming an integral joint is disposed. ing.
Since the assembly method of the segment 4 having the joint structure according to the second embodiment is the same as that of the first embodiment described above, detailed description thereof is omitted.

  In the second embodiment, the joining of the segments 4 and 4 adjacent to each other is performed in the first female joint 20A in which the second male joints 10B and 10B divided into two parts are integrally formed. Since the second male joints 10B and 10B are held by the first female joint 20A by engaging, there is no gap between the piece joint surfaces 4c and 4d, and a strong joint structure is obtained. be able to.

The first and second embodiments of the joint structure according to the present invention and the segment including the joint structure have been described above. However, the present invention is not limited to the above-described embodiments, and the scope does not depart from the spirit of the present invention. It can be changed as appropriate.
For example, in this embodiment, the segment is an article, but the present invention is not limited to the segment. As articles, for example, floor slabs, box culverts, fluid transport pipes and the like can be targeted.
Moreover, although the coating coating part 3 is provided in this Embodiment, it is not limited to this, Another structure may be sufficient. For example, as in the case of the skin plate 2, an arc plate-shaped steel plate joined to the inner peripheral surface 2a of the skin plate 2 by welding or the like can be used, and if the coating portion 3 (inner plate portion) is unnecessary. It can be omitted.

And in this 1st and 2nd embodiment, although the skin plate 2 which consists of a steel plate which makes a circular arc plate shape is used as an outer shell board, it is not limited to a steel plate, For example, predetermined | prescribed You may employ | adopt what processed carbon fiber, glass fiber, etc. which have intensity | strength into the circular arc board shape.
Moreover, it is limited to the thickness dimension, installation location, installation quantity of the male joint 10 and the female joint 20, and the arrangement and shape of the convex portion 11, the concave portion 21, the male die, the female tapered surface 11b, 21a, etc. The outer diameter of the tunnel, the outer diameter, the size, and the shape of the segment can be arbitrarily set. Further, the number of divisions of segment 1 is not limited to three divisions.
In addition, in the first and second embodiments, the male joint is protruded from the joint surface of the segment in the tunnel axial direction, and the female joint is accommodated in the range of the inner surface of the segment so as not to protrude from the joint surface. However, this may be reversed so that the female joint protrudes and the male joint does not protrude. Moreover, you may make it protrude both by adjusting protrusion amount. Then, in the first and second embodiments, the joint is attached to the inner surface of the segment. However, depending on the article, it may be difficult to attach the inner surface to the inner surface of the surface. There may be no problem. In that case, it may be attached to the outer surface of the article.

It is a perspective view of a segment by a first embodiment of the present invention. It is a perspective view which shows the joining state of a segment. It is a partially broken enlarged view of the segment shown in FIG. FIG. 3 is a developed plan view showing a joining state of segments shown in FIG. 2. It is a top view which shows a segment. It is a side view of a segment, (a) is a figure showing the male type joint, and (b) is a figure showing a female type joint. It is a figure which shows the mine conveyance state of the segment in the vicinity of a subsequent installation. It is a side view which shows the structure of a shield jack. It is a figure which shows the joining state of the segment by 2nd embodiment of this invention, Comprising: The figure corresponding to FIG. It is a top view of the segment shown in FIG.

Explanation of symbols

1, 4 segments (articles)
1a, 4a First inter-ring joint surface 1b, 4b Second inter-ring joint surface 1c, 1d, 4c, 4d Inter-piece joint surface 2 Skin plate (outer shell plate)
3 Coating part (inner plate-like part)
10 male joint 10A first male joint (male joint formed integrally)
10B 2nd male joint (male joint divided into two)
11 convex part 11a tip taper part 11b male side taper surface (first taper surface)
20 female joint 20A first female joint (integrated female joint)
20B Second female joint (female joint divided into two)
21 Concave portion 21a Female side taper surface (second taper surface)

Claims (6)

An article joint structure for butting and joining articles consisting of a male joint attached to the surface of one article and a male joint attached to the surface of the other article,
The male joint is formed into a thin plate shape, and a first tapered surface is formed on the side of the thin plate, the first taper surface gradually increasing in thickness along the thickness direction of the article,
The female joint has a notch shape that engages with the male joint, and a second tapered surface is formed on the side surface of the notch part, the notch part width dimension gradually increasing inward in the thickness direction of the article. The joint structure characterized by being made. The article of claim 1 is a segment,
The male joint and the female joint are arranged on the inner surface side of the segment, and are attached to the joint surface side between the rings.   The segment having the joint structure according to claim 2, wherein the male joint protrudes from a joint surface between the rings.   The segment having the joint structure according to claim 2 or 3, wherein the male joint has a shape divided into two in the circumferential direction on the joint surface in the circumferential direction of the tunnel.   The segment having a joint structure according to any one of claims 2 to 4, wherein the female joint has a shape divided into two in the circumferential direction on a joint surface in a tunnel circumferential direction. The segment is composed of an outer shell plate formed in an arc plate shape, and an inner plate-like portion forming a thin plate shape provided along the inner peripheral surface of the outer shell plate,
3. The male joint and the female joint are respectively attached to the inner peripheral surface side of the outer shell plate, and are flush with the inner peripheral surface of the inner plate-like portion. A segment comprising the joint structure according to claim 5.

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