JP2000104494A - Segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a segment which can facilitate filling work in filling plural insert holes formed in one joining portion of a pair of segments with a filler. SOLUTION: Plural joining grooves 2 having a joining metal fitting 3 are formed on both side joining surfaces 1a, and with the joining surfaces 1a abutting on each other, a connecting metal fitting 4 is inserted in an insert hole formed by the joining groove parts 2 to connect the joining metal fittings 3 to each other, thereby constructing a tunnel wall body. The segment has a communicating passage 30 for communicating plural grooves 2 formed in the same joining surfaces 1a to each other and a filling passage 31, one end of which is opened to one of plural joining grooves formed in the same joining surface and the communicating passage 30, and the other end of which is opened to the inner peripheral surface 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a segment that forms a cylindrical wall in the axial direction of a drilled hole by connecting a plurality of holes to each other.

[0002]

2. Description of the Related Art As a method of constructing a tunnel, a so-called shield method is generally used, in which a concrete wall is constructed by assembling a concrete segment on the inner surface side of an excavation hole. As the segments used in this shield method, those having a plane rectangular shape and an arc plate shape are mainly used, and these segments are joined to each other by bolts. As a structure for joining the segments with the bolts, a joint plate having holes communicating with each other when the joint surfaces of the segments are brought into contact with each other is buried in the vicinity of the joint surface of the segments, and these joint plates are embedded. Insert the bolt into the hole of
A structure in which a nut is fastened and joined to the bolt is generally used. Further, there is also a structure in which an insert fitting as a nut member is embedded in each segment, and bolts penetrating adjacent segments are fastened to each other for joining.

However, in such a structure, a bolt is inserted into a hole formed in a joint surface of a joint at a construction site, a nut is fastened to the bolt, or a bolt is inserted into an insert fitting embedded in each segment. Therefore, there is a limit in shortening the assembling time, and it is difficult to adapt to automatic assembling by a robot. Furthermore, even if the secondary lining is omitted, it is necessary to close the bolt box formed in the segment in order to install the bolt and nut, and a new joint is aimed at speeding up the construction and saving labor. At present, the development of the structure was urgently needed.

[0004] Here, as a joining structure that allows the segments to be joined very easily, a C-shaped joining bracket is embedded at a position opposing the joining surface of the segments.
By fitting the I-shaped connecting fittings whose both ends are engaged with these C-shaped connecting fittings, the C-shaped connecting fittings are connected to each other by the I-shaped connecting fittings, and the joining surfaces of the segments are joined together. Is being developed.

[0005]

Some of the above segments have a structure in which a plurality of joining grooves are formed on both joining surfaces, and in the case of such a segment, the joining surface of a pair of segments is used. When the insertion grooves are formed by joining the joint grooves by abutting each other, it goes without saying that a plurality of such insertion holes are formed at one joint of the pair of segments.
In the case of a segment having such a structure, when a filler such as mortar is filled into the insertion hole in order to fix the joint and prevent corrosion of the joint due to water stoppage, one joint between the pair of segments is used. A plurality of insertion holes formed at different locations must be individually filled, and there is a problem that the operation becomes complicated.
Accordingly, an object of the present invention is to provide a segment that can easily perform a filling operation when filling a plurality of insertion holes with a filler at one joint of a pair of segments. .

[0006]

In order to achieve the above object, in the segment according to the first aspect of the present invention, a plurality of joining grooves are formed on both joining surfaces, and the joining grooves have inner ends. A joint fitting having a pair of hook-shaped locking portions that are bent into locking pieces is provided,
In a state where the joining surfaces are butted against each other and the joining fittings are opposed to each other, the joining fittings are arranged in insertion holes formed by the joining groove portions, and are disposed in engagement spaces formed between the locking portions. By inserting, from one side, connecting fittings in which engaging portions for engaging with the locking pieces are provided on both sides of a plate-shaped fitting main body, the joining fittings are connected to each other to form a tunnel wall body. Which comprises
A communication path that allows the plurality of bonding grooves formed on the same bonding surface to communicate with each other, and one end of which opens to one of the plurality of bonding grooves and the communication path that is formed on the same bonding surface; And an injection passage opening to the inner peripheral surface. Thereby, since the communication path which connects the plurality of bonding grooves formed on the same bonding surface to each other is provided, the plurality of insertion holes formed by the bonding grooves and formed at one bonding point of the pair of segments are formed. At the time of filling the filler, if the filler is filled from the opening on the inner peripheral surface side of the injection passage, all the insertion holes formed by the communication passage and the joining groove can be filled with the filler at one time. .

[0007] The segment according to claim 2 of the present invention is characterized in that, with respect to the segment according to claim 1, the injection passage has one end opening to the communication passage. As described above, since the injection passage has one end opened in the communication passage that allows the insertion holes to communicate with each other, it is possible to prevent the filling material from being unevenly filled in the specific insertion hole.

[0008] A third aspect of the present invention is the segment according to the first or second aspect, wherein the communication path is formed by a groove opening to the joint surface side.
As described above, since the communication path is formed by the groove portion that opens to the joint surface side, if a convex portion is provided on the mold at the time of manufacturing, the communication path is formed only by pouring concrete and then removing the mold. Will be.

A segment according to a fourth aspect of the present invention is the segment according to any one of the first to third aspects, wherein the injection passage comprises an inner peripheral portion of a buried tube. . As described above, since the injection passage is formed by the inner peripheral portion of the buried pipe, if the pipe is set in the injection passage before casting the concrete at the time of manufacturing, the concrete is cast thereafter and the formwork is formed. By simply removing, the injection passage is formed.

According to a fifth aspect of the present invention, in the segment according to any one of the first to fourth aspects, one end of each of the plurality of joining grooves formed on the same joining surface is individually opened. The other end has a plurality of air vent passages that are individually opened on the inner peripheral surface. Accordingly, when the filler is filled from the opening on the inner peripheral surface side of the injection passage, air is satisfactorily removed from the air vent passage of each insertion hole with the filling of the filler. Then, finally, the filler overflows from all the air vent passages, thereby confirming that the filler has been filled in all the insertion holes.

According to a sixth aspect of the present invention, there is provided the segment according to the fifth aspect, wherein the air vent passage is formed by an inner peripheral portion of a buried pipe. As described above, since the air vent passage is formed by the inner peripheral portion of the buried pipe, if the pipe is set in the air vent passage before casting the concrete at the time of manufacturing, concrete is cast thereafter and the formwork is formed. The air vent passage is formed only by removing.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention. 1 to 5, reference numeral 1 denotes a segment. The segments 1 are made of concrete formed in a rectangular shape in a plan view and in an arc plate shape in a side view. By joining the joining surfaces 1a at the ends in the circumferential direction of these segments 1 to each other, the inside of the excavation hole is formed. A ring constituting the cylindrical wall is constructed. Then, by joining this ring sequentially from the wellhead side of the excavation hole to the face side of the shield machine, a cylindrical wall body is constructed. In these segments 1, as shown in FIG. 1, a joining groove 2 extending in the direction along the axis of the drill hole, that is, the axis of the segment 1, is formed on the joining surface 1 a in the thickness direction (radial direction) of the segment 1. More specifically, two rows are formed.

Each of these joining grooves 2 is provided with a plurality of concretely two C-shaped joining metal fittings 3 along the axial direction of each segment 1, and one segment 1 and another segment 1 are opposed to each other. The joining fittings 3 are connected to each other by the I-shaped connecting fitting 4.

As shown also in FIGS.
Is provided with a pair of hook-shaped locking portions 6 having locking pieces 5 at the ends so as to face each other, and is opposed to the locking pieces 5 of the pair of locking portions 6. The sides are connected to form a C-shape in side view. The space formed by these locking portions 6 matches the joining groove 2, and is an engaging space 8 in which the engaging portion 7 of the connection fitting 4 is engaged.

A locking surface 9 formed by the inner surface of the locking piece 5
Is a tapered surface that narrows the engagement space 8 toward the insertion direction A of the connection fitting 4. That is, in a state where the joining surfaces 1a of the segments 1 abut against each other, the engaging surfaces 9 of the joining fittings 3 facing each other are tapered surfaces that gradually approach toward the rear in the insertion direction of the connecting fittings 4.

A plurality of, specifically, three projections 14 are arranged in the joining fitting 3 along the direction in which the connecting fitting 4 is inserted. Screw portions 10 are respectively formed.
An anchor bar 11 is screwed and connected to each of the anchor bar connecting female threads 10 in a state of extending to the opposite side to the locking unit 6. A support plate 12 that is substantially perpendicular to the axis of the anchor bar 11 is integrally formed at the end of the anchor bar 11.

Further, in the joint 3, the side wall 6 a constituting the locking portion 6 is gradually thicker toward the rear side in the insertion direction of the connecting member 4.
A plurality of ribs 13 are formed at the connection position with the first bracket 1 in a direction intersecting the insertion direction A of the connection fitting 4.

In this embodiment, a plurality of, specifically, two rows of connecting grooves 2, 2 formed in one joint surface 1a in one segment 1 communicate with each other. Is formed only at the wellhead end of the borehole. Here, the communication path 30 is formed of a groove that opens to the joint surface 1a side over the entire length.

In this embodiment, in one segment 1, one end opening 31a is opened in the communication passage 30 and the other end opening 31b is arranged on the inner peripheral surface side of the tunnel or the inner peripheral surface of the tunnel. Only one linear injection passage 31 is formed in the inner peripheral surface 1b. It should be noted that one end opening 31a of the injection passage 31 is not formed in the communication passage 30 but in the plurality of joint grooves 2, 2 formed in one joint surface 1a.
May be opened to any one of them.

In addition, in this embodiment, one end opening 32a is individually formed in each of the plurality of joining grooves 2, 2 formed in one joining surface 1a in one segment 1.
Are formed, and a plurality of linear air vent passages 32, 32, each of which has an opening 32b at the other end thereof individually opened at the inner peripheral surface 1b, are formed at the face side end of the shield machine.

Such a communication path, an injection passage and an air vent passage are formed in a plurality of, specifically, two rows of the joining grooves 2, 2 formed on the opposite joining surface 1a in the one segment 1. Not.

As shown in FIG. 9, the segment 1 having such a structure is a male type 2 for forming the joining grooves 2.
Convex portion 20b for forming communication passage 30 with 0a, 20a
Are formed on one side, and the male side 20a,
The male mold 20a is attached to the mold 20 in which only the mold 20a is formed.
The fittings 3 (not shown in FIG. 9) are engaged with the predetermined positions of the rods 20c and 20 at the positions where the injection passage 31 and the air vent passages 32 and 32 are formed.
The concrete is poured into the formwork 20 with the d and 20d arranged, and then the formwork 20 is removed and the rod 2
It is manufactured by extracting 0c, 20d, and 20d.

It should be noted that concrete is punched into the formwork 20 with pipes made of vinyl chloride or the like instead of the rods 20c, 20d, 20d arranged at the positions where the injection passage 31 and the air vent passages 32, 32 are formed. If provided, the segment 1 is manufactured only by removing the formwork 20 thereafter. That is, in this case, the injection passage 31 is formed of the inner peripheral portion of the buried pipe, and the air vent passage 3
2 and 32 also consist of the inner periphery of the buried tube.

The connecting fitting 4 for connecting the joining fittings 3 between the segments 1 is formed in an I-shaped cross section as shown in FIG. 10, and both sides of the plate-shaped connecting fitting body 21 are as described above. Thus, the engaging portion 7 is fitted into the engaging space 8 of the joint fitting 3. The connection fitting main body 21 includes the joining fitting 3.
Are formed so as to be thinner than the gap between the locking pieces 5 of the locking section 6 and can be inserted, and the engaging section 7 is formed to be thicker than the gap between the locking pieces 5. . Further, the engaging surface 22 formed on the engaging portion 7 of the connecting fitting 4 which comes into contact with and engages with the locking surface 9 of the locking piece 5 of the joining fitting 3 is in contact with the engaging surface 9 of the joining fitting 3. It has the same tapered surface.

The joining metal fitting 3 has a wellhead 3 (3A) on the wellhead side of the excavation hole in the joining groove 2, that is, a joining side to the existing ring, and has a cutting face side of the wellbore. The side on which the shield machine for excavating the ground is provided is the face-side joining metal fitting 3 (3B).
On the other hand, each connection fitting 4 is connected to the wellhead-side connection fitting 3 (3
A) The one connecting the two is the wellhead side connection fitting 4 (4A).
The face-face connecting metal fittings 3 (3B) are connected to each other to form a face-face connecting metal fitting 4 (4B).

When the joints 4 (4A) are inserted into the insertion holes 23 formed from the joint grooves 2 in a state where the joining surfaces 1a of the segments 1 abut against each other, Engaging part 7 of connecting metal 4 (4A)
However, it passes through the engaging space 8 of the cutting face type connecting metal fitting 3 (3B) and engages with the wellhead side connecting metal fitting 3 (3A).

That is, the minimum distance L1 between the engaging portions 7 of the wellhead side connection fitting 4 (4A) is equal to the joining surface 1a of the segment 1.
Face-side joining metal fittings 3 in a state where they are butted against each other
(3B) is larger than the maximum distance L2 between the inner surfaces of the locking pieces 5, and the maximum width dimension L3 of the wellhead-side connection metal fitting 4 (4A) is such that the joining surfaces 1a of the segments 1 abut each other. The gap L4 between the bottoms forming the engagement space 8 of the face-side joining metal fitting 3 (3B) is set to be smaller than that (see FIG. 3). In addition, the joining metal fitting 3 and the connecting metal fitting 4 are both rounded at their corners so that stress concentration does not occur.

Next, the case of joining the segments 1 will be described with reference to FIGS. Segment 1
To join them, first, the joining surfaces 1a in the circumferential direction of these segments 1 are brought into contact with each other. In this manner, the joining grooves 2 formed on the joining surfaces 1a of the respective segments 1 abut each other to form the insertion holes 23. In this state, firstly, the wellhead side connection fitting 4
(4A) is inserted from the insertion hole 23 and pushed.

In this way, the wellhead side connection fitting 4
(4A) first passes between the cutting face-side joint fittings 3 (3B), and is further pushed in, so that the wellhead-side connection fitting 4 (4A) reaches the wellhead-side joint fitting 3 (3A). The wellhead side fitting 3 (3A) is fitted. That is, the engaging portion 7 of the wellhead side connection fitting 4 (4A) fits into the engagement space 8 of the wellhead side joining metal fitting 3 (3A), and each wellhead side joining metal fitting 3 (3A) fits on the wellhead side. They are connected to each other by a connection fitting 4 (4A) (see FIG. 11). Here, the engaging surface 22 formed of the tapered surface of the engaging portion 7 of the wellhead-side connection fitting 4 (4A) is engaged with the locking piece 5 of the wellhead-side joint fitting 3 (3A).
By sliding in contact with the locking surface 9 formed of the tapered surface, the respective wellhead-side joint fittings 3 (3A) are attracted to each other.

Next, a spacer 24 made of resin or the like is inserted into the insertion hole 23 (see FIG. 12). After that, the cutting-face-side connecting bracket 4 (4B) is inserted into the insertion hole 23 and pushed. By doing so, the face-side connecting bracket 4 (4
B) is fitted to the face-side joining metal fitting 3 (3B). That is, the engaging portion 7 of the face-side connecting metal fitting 4 (4B) fits into the engaging space 8 of the face-side connecting metal fitting 3 (3B),
The respective face-side connecting metal fittings 3 (3B) are connected to each other by the face-side connecting metal fittings 4 (4B) (see FIG. 13). Also in this case, the engaging surface 22 formed of the tapered surface of the engaging portion 7 of the face-side connecting metal fitting 4 (4B) is locked by the tapered surface of the locking piece 5 of the face-side connecting metal fitting 3 (3B). By sliding in contact with the surface 9, the respective face-side joining metal fittings 3 (3B) are attracted to each other.

Further, a spacer 25 made of resin or the like is fitted into the insertion hole 23. The above operations are performed on all of the plurality of insertion holes 23 to complete the joining of the segments 1 (see FIG. 14).

In this way, in the borehole, all the segments 1 at the same position in the axial direction are joined in the circumferential direction to construct a ring (hereinafter referred to as a previous ring) 40, and then the segment 40 is attached to the ring 40. By shifting the position in the circumferential direction of the joining point between 1, 1
The next ring (hereinafter referred to as the next ring) 41 is constructed on the face side in the same manner as described above. Then, all the openings on the side of the ring 41 next to the insertion hole 23 of the previous ring 40 are closed by the next ring 41. As a result, the joining fittings 3 (3A) and 3 (3B) and the spacer 24 and 25 are prevented from coming off (see FIG. 15).

In this state, when the filler 42 such as mortar is filled from the opening 31b of the inner peripheral surface 1b of the injection passage 31 of the previous ring 40, the filler 42 is
From the air vent passages 32, 32 of the through holes 23, 23 with the filling of the filler 42 (FIG. 16). reference). Finally, both air vent passages 32, 3
When the filler 42 overflows from the hole 2, the two insertion holes 23, 23
When it is confirmed that the filling material 42 has been filled into the joint, the filling operation of the filling material 42 into this joining point is ended. Then, such a filling operation is performed for all the joints.

According to segment 1 of the above embodiment,
Since the communication path 30 that connects the plurality of joining grooves 2 and 2 formed on the same joining surface 1a to each other is provided, the communication path 30 is constituted by the joining grooves 2 and 2 and is located at one joint of the pair of segments 1 and 1. On the other hand, when filling the plurality of insertion holes 23, 23 with the filler 42, the filler 42 is filled from the opening 31b on the inner peripheral surface 1b side of the injection passage 31 provided for one joining point. When the filler is filled, the filler 42 can be filled at once into all the insertion holes 23 formed by the communication passage 30 and the connection grooves 2 provided for one connection point. Therefore, the filling operation can be easily performed.

In addition, the injection passage 31 is provided with the insertion holes 23, 2
Since one end is opened in the communication passage 30 that communicates the three, the filling material 42 can be prevented from being unbalancedly filled in the specific one of the insertion holes 23, 23. Therefore, the filler 42 can be uniformly filled in all the insertion holes 23, 23.

Further, since the communication path 30 is formed by a groove opening toward the joint surface 1a, the projection 20
If b is provided, then concrete is poured and formwork 20
The communication path 30 is formed only by removing Therefore, the communication path 30 can be easily formed.

When the filler 42 is filled from the opening 31b on the inner peripheral surface 1b side of the injection passage 31, the air vent passages 32, 3 of the insertion holes 23, 23 are filled with the filling of the filler 42.
2 will be well ventilated. Therefore,
Filling of the filler 42 into the insertion holes 23, 23 can be performed more favorably.

Then, finally, all the air vent passages 3
When the filler 42 overflows from the holes 2 and 32, it is confirmed that the filler 42 has been filled in all the insertion holes 23 and 23. Therefore, all the insertion holes 23, 23
The filling material 42 can be filled reliably.

In addition, if the injection passage 31 is constituted by the inner peripheral surface of the buried pipe, if the pipe is set in the injection passage 31 before casting concrete during manufacturing, The casting passage 31 is formed only by casting concrete and removing the formwork 20. Therefore, with such a configuration, the injection passage 31 can be easily formed.

Similarly, if the air vent passages 32, 32 are constituted by the inner peripheral portions of the buried pipes, if the pipes are set in the air vent passages 32, 32 before the concrete is cast at the time of manufacturing, the pipes will be disposed later. The air vent passages 32, 32 are formed only by casting the concrete and removing the formwork 20. Therefore, with such a configuration, the air vent passages 32, 32 can be easily formed.

[0041]

As described above, according to the segment of the present invention, the following effects can be obtained. Claim 1
According to the described segment, since a communication path is provided to allow the plurality of joining grooves formed on the same joining surface to communicate with each other, a plurality of joining grooves are formed at one joining point of the pair of segments. When filling the insertion hole with the filler, if the filler is filled from the opening on the inner peripheral surface side of the injection passage, all the insertion holes formed by the communication passage and the joint groove are filled with the filler at once. be able to. Therefore, the filling operation can be easily performed.

According to the second aspect of the present invention, since the injection passage has one end opened in the communication passage connecting the insertion holes, the filling material is unbalancedly filled in the specific insertion hole. Can be prevented. Therefore, the filler can be evenly filled in all the insertion holes.

According to the third aspect of the present invention, since the communication path is formed by a groove opening toward the joint surface,
If a convex portion is provided on the formwork, the communication path is formed only by casting concrete and then removing the formwork. Therefore, the communication path can be easily formed.

According to the fourth aspect of the present invention, since the injection passage is formed by the inner peripheral portion of the buried pipe, if the pipe is set in the injection passage before casting the concrete at the time of manufacturing, the injection passage can be formed later. The casting path is formed only by casting concrete and removing the formwork. Therefore, the injection passage can be easily formed.

According to the segment of the fifth aspect, when the filler is filled from the opening on the inner peripheral surface side of the injection passage, air is satisfactorily removed from the air vent passage of each insertion hole with the filling of the filler. Will be. Therefore, the filling material can be more preferably filled into the respective insertion holes. And
Finally, the overflow of the filler from all the air vent passages confirms that all the insertion holes have been filled with the filler. Therefore, it is possible to reliably fill all the insertion holes with the filler.

According to the sixth aspect of the present invention, since the air vent passage is formed by the inner peripheral portion of the buried pipe, if the pipe is set in the air vent passage before casting the concrete during manufacturing, The air vent passage is formed only by casting concrete and removing the formwork. Therefore, the air vent passage can be easily formed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of one joint of segments according to an embodiment of the present invention.

FIG. 2 is a perspective view of one joint of the segments according to the embodiment of the present invention.

FIG. 3 is a plan cross-sectional view of one joining point of the segments according to the embodiment of the present invention.

FIG. 4 is a side sectional view of one joining point of the segments according to the embodiment of the present invention.

FIG. 5 is a plan cross-sectional view of a part of one joining point of the segments according to the embodiment of the present invention.

FIG. 6 is a plan view of a fitting used for joining the segments according to the embodiment of the present invention.

FIG. 7 is a side view of a joint used for joining the segments according to the embodiment of the present invention.

FIG. 8 is a rear view of the joint fitting used for joining the segments according to the embodiment of the present invention, from which an anchor streak is removed.

FIG. 9 is a perspective view of a mold for manufacturing a segment according to an embodiment of the present invention, with a part of a front side thereof removed;

FIG. 10 is a perspective view of a connection fitting used for joining the segments according to the embodiment of the present invention.

FIG. 11 is a cross-sectional view of a joining portion between the segments for explaining a joining procedure between the segments according to the embodiment of the present invention.

FIG. 12 is a cross-sectional view of a joining portion between segments for explaining a joining procedure between segments according to the embodiment of the present invention.

FIG. 13 is a cross-sectional view of a joining portion between the segments for explaining a joining procedure between the segments according to the embodiment of the present invention.

FIG. 14 is a cross-sectional view of a joining portion between segments for explaining a joining procedure between segments according to the embodiment of the present invention.

FIG. 15 is a cross-sectional view of a joining portion between the segments for explaining a joining procedure between the segments according to the embodiment of the present invention.

FIG. 16 is a cross-sectional view of a joining portion between the segments, viewed from the Z direction shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 segment 1a joining surface 1b inner peripheral surface 2 joining groove 3 joining metal fitting 4 connecting metal fitting 5 locking piece 6 locking part 7 engaging part 8 engaging space 21 connecting metal fitting body 23 insertion hole 30 communication passage 31 injection passage 32 air vent aisle

Claims (6)

[Claims] 1. A joining bracket having a plurality of joining grooves formed on both joining surfaces, and having a pair of hook-shaped engaging portions each of which has an inwardly bent engaging piece in each of the joining grooves. In the state where the joining surfaces are butted against each other and the joining fittings are opposed to each other, an engagement hole formed between the locking portions is formed in an insertion hole formed by the joining groove portions. By inserting, from one side, connecting metal fittings provided in both sides of a plate-shaped metal fitting body, the engaging metal fittings that are arranged in the joint space and engage with the locking piece parts allow the bonding metal fittings to be connected to each other. A segment that is connected to form a tunnel wall, and that communicates with each other a plurality of joining grooves formed on the same joining surface; and a plurality of joining grooves formed on the same joining surface and the plurality of joining grooves. Any one of the passages And an injection passage whose one end is open and the other end is open on the inner peripheral surface. 2. The segment according to claim 1, wherein the injection passage has one end opened to the communication passage. 3. The segment according to claim 1, wherein the communication path is formed by a groove that opens to the joint surface side. 4. The segment according to claim 1, wherein the injection passage comprises an inner peripheral portion of a buried tube. 5. A plurality of air vent passages each of which has one end open to each of the plurality of joint grooves formed on the same joint surface and the other end of which individually opens to the inner peripheral surface. The segment according to any one of claims 1 to 4, wherein 6. The segment according to claim 5, wherein said air vent passage is formed by an inner peripheral portion of a buried pipe.