JP3363071B2 - Connection structure of tunnel segment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an existing segment main body which is connected while being moved in the longitudinal direction of the tunnel so as to be adjacent to each other in the circumferential direction of the tunnel.
A first dovetail groove portion and a second dovetail groove portion are separately provided so as to face the abutting portions of the segment body and the second segment body in a state of abutting the abutting portions, and the first dovetail groove portion is provided. A connector provided with a first expandable edge part that can be inserted and a second expandable edge part that can be inserted into the second dovetail groove part on both sides was inserted into the first dovetail groove part. In the state, after connecting the first segment body to the existing segment body adjacent in the tunnel longitudinal direction, by pressing the second segment body to the first segment body side and the existing segment side, The second enlarged edge is inserted inside the second dovetail groove,
Further, the present invention relates to a tunnel segment connecting portion structure for connecting the first segment main body and the second segment main body by attracting the first dovetail groove portion and the second dovetail groove portion by the connecting tool.

[0002]

2. Description of the Related Art Conventionally, there has been, for example, a structure shown in FIG. 7 as a connecting portion structure of this kind of tunnel segment. That is, the first sandwiching portion B1 provided inside the first enlarged edge portion A1 of the connector R and the second sandwiching portion B2 provided inside the second enlarged edge portion A2 are configured to be non-parallel and First clamped portion C1 provided in the first dovetail groove portion M1 of the 1-segment main body S1
And the second clamped portion C2 provided in the second dovetail groove M2 of the second segment main body S2, and the connector R is inserted into the first dovetail groove M1 and the second dovetail groove M2 and the wedge thereof is inserted. Due to the effect, both segment bodies S1 and S2 are fastened. However, in this case, the first is important
-The second sandwiched portions B1 and B2 and the first and second sandwiched portions C1 and C
2 is in contact with each other, and the outer diameter dimensions of the first and second enlarged edge portions A1 and A2 are, for example, the first and second dovetail groove portions M1 and M1.
Matching with the inner diameter dimension of M2 is less of an issue. Therefore, in the conventional connecting portion structure, in order to ensure the insertion of the connecting tool R, the first and second dovetail groove portions M1 and M2 are provided.
It was often the case that the inner diameter dimension of was set slightly larger than the outer diameter dimension of the first and second enlarged edge portions A1 and A2.

[0003]

However, the inner diameters of the first and second dovetail groove portions M1 and M2 have the first and second enlarged edge portions A.
If it is larger than the outer diameter dimension of A1 and A2, the connector easily rattles with respect to the first segment body S1 in a state before the second segment body S2 is coupled. As a result, as shown in FIG. 7, the second enlarged edge portion A2 may be located too close to the first segment body S1 side. In this case, the first segment body S
Even if the second segment main body S2 is brought close to 1, the positions of the opening of the second dovetail groove M2 and the second enlarged edge portion A2 cannot be made to coincide with each other, so that the second segment main body S2 is forced.
When pushing in, there is a problem that the connector R and the end of the second segment body S2 are damaged. In particular,
When the connector R is damaged, the construction of the first segment body S1 has already been completed, so that the replacement work of the connector R becomes very complicated. Since such an inconvenience may occur, the second segment main body S is conventionally used.
Before connecting the two, always check whether the initial position of the connecting tool R is appropriate, and also when connecting the second segment main body S2, the second dovetail groove M2 and the second enlarged edge portion. Before inserting A2 and A2, it is necessary to pay close attention so as not to accidentally shift the position of the connecting tool R, which requires a lot of time and effort in connecting the segment main bodies.

An object of the present invention is to solve the above drawbacks of the prior art and to provide a tunnel segment connecting portion structure capable of smoothly connecting the segment main bodies.

[0005]

[Means for Solving the Problems]

(Structure 1) In the tunnel segment connecting portion structure of the present invention, as described in claim 1, prior to inserting the first enlarged edge portion into the first dovetail groove portion, in the insertion direction of the first enlarged edge portion. The first of the opposite ends of the first enlarged edge along
It is characterized in that a position fixing member for positioning the rear side end portion located on the rear side of the dovetail groove portion on the second segment main body side inside the first dovetail groove portion is configured by being inserted into the first dovetail groove portion. Have. (Operation / Effect) As in the present configuration, the position fixing member is provided inside the first dovetail groove portion, and the far-side end portion located at the far side of the first dovetail groove portion out of both end portions of the first enlarged edge portion. Is located on the side of the second segment body, the second enlarged edge portion of the connector can be maintained in a state of being reliably projected from the abutting portion of the first segment body. Therefore, when connecting the second segment main body to the first segment main body, the second enlarged edge portion and the second dovetail groove portion can be smoothly inserted.

(Structure 2) In the structure for connecting the tunnel segments of the present invention, as described in claim 2,
The position fixing member has a cross-sectional shape that is substantially the same as the cross-sectional shape of the first dovetail groove so that the position fixing member can be inserted into the first dovetail groove, and has a concave portion that abuts against the rear end portion. Can be configured into one. (Operation / Effect) In the case of this configuration, the position fixing member is insertable inside the first dovetail groove while having a cross-sectional shape substantially similar to the cross-sectional shape of the first dovetail groove, Since it can come into contact with the end portion, in most cases, the position fixing member is inserted into the first dovetail groove portion so as to be on the back side with respect to the connector. With this configuration, when the second segment main body is pressed toward the existing segment main body, there is no hindrance in sliding the coupling tool toward the existing segment main body. That is, since the connecting tool does not hinder the sliding of the inside of the first dovetail groove portion, the fastening function of the connecting tool described later is not impaired, and the first segment main body and the second segment main body are appropriate. It is possible to connect with a strong attractive force.

(Structure 3) In the tunnel segment connecting portion structure of the present invention, as described in claim 3,
The position fixing member is attached to the outer side of the inner end portion, and is composed of a deformable member that can be filled between the outer surface of the inner end portion and the inner surface of the first dovetail groove portion. You can also (Operation / Effect) Even when the position fixing member is configured as in the present configuration, the same effect as the above configuration 2 can be obtained. Moreover, in the case of this configuration, the structure itself of the position fixing member is further simplified, and since the position fixing member is deformable, strict finishing dimensions are not required. Therefore, the manufacturing of the position fixing member is facilitated, and the function of holding the position of the connector is stably exhibited regardless of the finishing accuracy of the position fixing member.

(Structure 4) In the structure for connecting the tunnel segments of the present invention, as described in claim 4,
Of both end portions of the second enlarged edge portion along the insertion direction of the second enlarged edge portion, a rear end portion located on the rear side of the second dovetail groove portion and an opening side end of the second dovetail groove portion. A chamfered part may be provided in the part. (Operation / Effect) With this configuration, the distance between the first enlarged edge portion and the second enlarged edge portion is enlarged, and as a result, the distance between the abutting portion of the first segment body and the second enlarged edge portion is widened. Can be secured. On the other hand, the chamfered portion provided in the second dovetail groove is similar to the case where the opening for inserting the second enlarged edge portion is brought close to the abutting portion side of the second segment body. As a result, even if the connector is attached to the first segment main body in a tilted manner, the second enlarged edge portion and the second dovetail groove portion can be easily and surely inserted.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Outline) FIG. 1 shows an outline of a tunnel segment connecting structure according to the present invention. The connection structure of the tunnel segment of the present invention allows the existing segment main body S and the first segment main body S1 to be already constructed by simply pressing the second segment main body S2 against the existing segment main body S and the first segment main body S1. In contrast, the second segment body S
2 is connected to construct the inner wall of the tunnel. still,
In the following embodiment, an example using a ductile segment as a tunnel segment to be connected is shown.
Other than this, it is also possible to use concrete segments, steel segments, or the like.

The connection between the first segment body S1 and the second segment body S2 is made by connecting the first dovetail groove M1 provided on the first butting surface F1 of the first segment body S1 and the second butting surface of the second segment body S2. Second dovetail groove M provided in F2
2 by inserting the connecting tool R. As shown in FIG. 2, the already constructed first segment body S
When the second segment main body S2 is connected to 1, the first dovetail groove M1 provided on the first butting surface F1 and the first dovetail groove M1 on the side of the existing segment main body S are previously provided in advance. The connecting tool R is inserted in advance. That is, the first enlarged edge portion A1 of the two enlarged edge portions A provided on the connecting tool R is inserted into the first dovetail groove portion M1. The first dovetail groove M1 is provided at each of the both ends of the first butting surface F1 along the longitudinal direction of the tunnel. The second dovetail groove M2 is also provided at two locations on the second butting surface F2. These first segment body S
By pressing the second segment body S2 against the connector 1 and the connector R, the other second enlarged edge portion A2 of the connector R protruding from the first butting surface F1 is moved to the second dovetail groove portion M2.
And the connecting tool R attracts the first dovetail groove M1 and the second dovetail groove M2 to connect the first segment body S1 and the second segment body S2.

The overall shape of the connecting tool R is substantially rectangular as shown in FIG. 1 or FIG. In the first enlarged edge portion A1 and the second enlarged edge portion A2, the portions facing each other are
A first sandwiching portion B1 and a second sandwiching portion B2 are formed respectively. The first sandwiching portion B1 and the second sandwiching portion B2 connect the connecting tool R to the first dovetail groove portion M of the first segment body S1.
When inserted in the second dovetail groove M2 of the first and second segment bodies S2, the first and second pinched portions C1 and C2 formed in the respective dovetail grooves M1 and M2 come into contact with each other, and This is for attracting the 1-segment main body S1 and the second segment main body S2. First holding part B
The first and second sandwiching portions B2 are non-parallel to each other, and are formed to have a tapered shape that widens toward the rear side in the insertion direction of the connecting tool R. According to this configuration, the fastening force that connects the first segment body S1 and the second segment body S2 is borne by the entire length of the connecting tool R in the longitudinal direction. Can be generated. Even if the first sandwiching portion B1 and the second sandwiching portion B2 are not parallel to each other, the first enlarged edge portion A1
And the second enlarged edge A2 do not necessarily have to be non-parallel.

(Position fixing member) When the connecting tool R is inserted into the first dovetail groove M1 in advance, for example, between the first enlarged edge A1 of the connecting tool R and the first dovetail groove M1. It is necessary to consider the backlash. That is, the connecting tool R is
It is inserted across the first dovetail groove M1 and the second dovetail groove M2, and the two first nipping portions B1 and the second nipping portions B2 form the first nipping portion C1 and the second nipping portion C2. Only when they come into contact, the attractive force is exerted. Therefore, if the first enlarged edge portion A1 is simply inserted into the first dovetail groove portion M1, the first enlarged edge portion A1 is easily rattled inside the first dovetail groove portion M1. When this backlash occurs, as described above, the second enlarged edge portion A2 protruding from the first butting surface F1 comes too close to the first butting surface F1 side, and the second enlarged edge portion A2 and the second It may not be possible to insert the dovetail groove M2. In order to prevent such an inconvenience, for example, as shown in FIGS. 1 and 2, the position fixing member D for preventing the positional displacement of the connecting tool R is provided in the first dovetail groove M1.
It is provided on the inner side of the connector than the connecting tool R. The position fixing member D has, for example, a substantially cylindrical shape, and
A recess D that has a cross-sectional shape that is substantially the same as the cross-sectional shape of the dovetail groove M1 and that is in contact with the rear end G of the connector R
1 is configured. That is, by bringing the rear end G of the connector R into contact with the recess D1, the first butting surface F1
The second enlarged edge portion A2 protruding from the first abutting surface F1.
Be surely separated from. This allows the second
When the segment main body S2 is connected, the projecting second enlarged edge portion A2 and the second dovetail groove portion M2 are smoothly inserted. The position fixing member D is preferably fixed to the rear end G of the connecting tool R with, for example, an adhesive. When the two are not fixed at all, when they are separately moved in the longitudinal direction of the first dovetail groove M1 inside the first dovetail groove M1, they are separated from each other, and the effect of the position fixing member D is reduced. Because it is not demonstrated. The position fixing member D is, for example, an ordinary steel material, aluminum,
Any material may be used as long as it can be configured by appropriately selecting a material such as copper, various resin materials, and paper, and can fix the position of the connecting tool R until the second segment body S2 is connected. You may comprise.

The position fixing member D can also be constructed as shown in FIG. That is, the position fixing member D does not necessarily have to have the concave portion as in the embodiment of FIG. 2, and as shown in FIG. 3, the position fixing member D has the outer surface of the rear end G of the connector R and the inner surface of the first dovetail groove M1. You may intervene in the gap of. For example, the position fixing member D made of a deformable material such as sponge may be filled in the gap.

Further, the position fixing member D is a connecting member R.
Was used for surely projecting from the first butting surface F1, but if the connecting work of the second segment main body S2 can be carried out smoothly, the second enlarged edge portion A on the projecting side.
There is no problem even if 2 is close to the first butting surface F1 side to some extent. That is, as shown in FIG. 4, of both end portions of the second enlarged edge portion A2 along the insertion direction of the protruding second enlarged edge portion A2, the far side end located on the far side of the second dovetail groove portion M2. The chamfered portion H is provided on the portion G and the opening-side end portion G1 of the second dovetail groove portion M2. The chamfered portion H provided on the second enlarged edge portion A2 enlarges the distance between the first enlarged edge portion A1 and the second enlarged edge portion A2 and protrudes from the first butting surface F1. It is possible to secure a wide range. On the other hand, the chamfered portion H provided in the second dovetail groove portion M2 is the second flat groove portion K related to the second dovetail groove portion M2.
The width of 2, that is, the width along the tunnel circumferential direction is reduced. Therefore, even if the connecting tool R is inclined to the first segment body S1 side, the second enlarged edge portion A2
And the second dovetail groove portion M2 is reliably inserted.

(Coupling operation) The process of coupling the first segment body S1 and the second segment body S2 using the coupling tool R is shown in FIGS. Figure 5 (a)
Is the first segment body S1 that has already been constructed.
And a process of bringing the second segment body S2 close to the connector R inserted into the first dovetail groove M1 of the first segment body S1. In this process, the connector R and the second segment body S
2 is not yet in contact. The second segment body S
FIG. 5B shows a state in which the pressing of No. 2 progresses and the second dovetail groove M2 is in contact with the second enlarged edge A2 of the coupling tool R. When the second segment body S2 is further pushed toward the existing segment body S, slippage occurs between the first dovetail groove portion M1 and the first enlarged edge portion A1, and the connecting tool R has its protrusion. The first dovetail groove portion M1 until the tip of the portion T contacts the existing segment body S.
Slide along. With this sliding, there is a margin in the width of the portion of the body portion J of the coupling tool R projecting from the first segment body S1, so that the second segment body S is provided.
2 can further enter the side of the existing segment body S. FIG. 5C shows a state in which the tip of the protruding portion T of the connecting tool R that has slid is in contact with the existing segment body S.

The function of the protrusion T will be described below. The tunnel segment connector R of the present invention is, for example, as shown in FIG.
Is provided at the rear end in the fitting direction. The protrusion T is configured by a hollow cylindrical member T1, and the protrusion T is fitted and fixed in a recess Rt provided at the rear end of the connecting tool R, for example. When the second segment main body S2 is pressed against the existing segment main body S, the protrusion T is pressed by the second dovetail groove M2 of the second segment main body S2 and abuts on the existing segment main body S, so that the predetermined segment It receives a compressive force and is deformed by compression as shown in FIG. A flange portion T2 is provided at least at the center of the cylindrical member T1 in the pressing direction. With this configuration, the shapes of the portions on both sides of the collar portion T2 are small in the aspect ratio in the pressing direction. Therefore, the cylindrical member T1
Although it has an elongated shape as a whole, the cylindrical member T1 can be shrunk and deformed in the pressing direction without being bent during the pressing.

After the tip of the protruding portion T abuts on the existing segment body S, the second segment body S2 is further pushed into the existing segment body S, and the second segment body S2 further intrudes. Then, the contact force between the first segment body S1 and the second segment body S2 is increased. However, at this stage, the protrusion T
No compressive deformation occurs. That is, both of the enlarged edges A
Since A1 and A2 are formed in a tapered shape, most of the force for pressing the second segment body S2 against the existing segment body S is a component force for attracting the two segment bodies S1 and S2. Becomes Therefore, the component force for pressing the connecting tool R toward the existing segment body S is
The force required to compressively deform the protrusion T has not yet increased. The second segment body S2
When the component force that pushes the connector R further toward the existing segment body S increases enough to compress and deform the protruding portion T, the protruding portion T causes compressive deformation, and eventually the surface The connector R is moved to the side of the existing segment body S by causing external deformation. As a result, since the connecting tool R moves to the side where the width of the first flat groove portion K1 related to the first dovetail groove portion M1 is narrow, both the enlarged edge portions A
A space is created in the space between 1 and A2, and the second segment body S2 further enters. In this state, the attraction force between the first segment body S1 and the second segment body S2 is kept substantially constant. In the connecting structure of the present invention, this attractive force can be easily set. That is, the inclination angles of the first and second enlarged edge portions A1 and A2 and the first and second dovetail groove portions M1 and M2 are appropriately changed, and the protruding portion T receives a compressive force and is compressed in the axial direction. The attraction force of the connecting tool R can be set by appropriately setting the load at the time of deformation. The load required for the compressive deformation of the protrusion T can be set by appropriately changing the material and wall thickness of the cylindrical member T1 or the slenderness ratio in the compression direction. As the material of the cylindrical member T1, it is possible to use aluminum, copper, lead, or a relatively easily deformable material such as thin steel material. That is, since plastic deformation performance is stable with these materials, the protrusion T having a desired deformability can be easily obtained. Further, as shown in FIG. 6, if the protruding portion T provided with the collar portion T2 in the central portion is used, the cylindrical member T1 is formed into a shape in which two pieces are connected to each other, and a compressive deformation is generated while generating a constant deformation resistance. It is possible to secure a long deformation stroke when performing.
As a result, even when the connecting tool R has a relatively large manufacturing error, it is possible to fasten the connecting tool R in a wide range of positions along the longitudinal direction of the dovetail grooves M1 and M2, and to obtain a substantially constant pulling force. The segment bodies S1 and S2 can be connected to each other by applying force.

FIG. 5D shows a state in which the second segment body S2 further pushed into the existing segment body S is then in contact with the existing segment body S. That is, this is a state in which the connection of the second segment main body S2 is completed.

As described above, the connecting tool R provided with the protruding portion T
By using, for example, both of the flat groove portions K1 and K2
Even if the total width of the two is narrower than the distance between the first sandwiching portion B1 and the first sandwiching portion B2, the connecting tool R is surely located inside the first and second dovetail grooves M1 and M2. It is possible to prevent the inconvenience of being left unattended inside the first and second dovetail grooves M1 and M2. Moreover, if the connecting tool R of the present invention is used, the manufacturing error of the first and second dovetail grooves M1, M2 or the connecting tool R itself is allowed to a certain range, while the first and second segment main bodies S1, It is also possible to connect the S2s with a substantially constant fastening force.

As described above, if the tunnel segment connecting portion structure of the present invention is used, the first construction already completed.
When connecting the second segment main body S2 to the segment main body S1, the posture of the connecting tool R can be appropriately maintained, so that the second segment main body S2 can be smoothly connected. Furthermore, by providing the protruding portion on the connecting portion, the first segment main body S1 and the second segment main body S2 can be connected in a state in which an appropriate attractive force is generated. Furthermore, if the connecting portion structure according to the present invention is used, the inner wall of the tunnel can be constructed by simply pressing the segment main body mainly in the longitudinal direction of the tunnel. As described above, it is not necessary to provide a large number of bolt pockets for connection, and the inner side surface can be configured to be a relatively smooth surface to save the labor such as secondary lining.

In the description of the claims, reference is made to the drawings, and reference numerals are given for convenience of comparison with the drawings. However, the present invention is not limited to the configuration of the accompanying drawings by the entry. Absent.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a structure of a connecting portion of a tunnel segment of the present invention.

FIG. 2 is a plan view showing a structure of a connecting portion of a tunnel segment of the present invention.

FIG. 3 is a plan view showing a structure of a connecting portion of a tunnel segment according to another embodiment.

FIG. 4 is a plan view showing a structure for connecting a tunnel segment according to another embodiment.

FIG. 5 is an explanatory view showing a connecting process of the second segment main body.

FIG. 6 is an explanatory diagram showing details of a protruding portion.

FIG. 7 is an explanatory view showing a structure of a connecting portion of a conventional tunnel segment.

[Explanation of symbols]

S Existing segment body S1 First segment body S2 Second segment body M1 1st dovetail groove M2 second dovetail groove A1 first enlarged edge A2 second enlarged edge R connector G Back end D position fixing member D1 recess H chamfer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiko Ishikawa 3-19-6 Higashi-Ueno, Taito-ku, Tokyo Inside the Teito High Speed Transportation Corps (72) Inventor Ken Watanabe 4-2 Shimohoya, Hoya-shi, Tokyo No. 13 (72) Inventor Yoshihiko Matsui 2-10-26 Fujimi, Chiyoda-ku, Tokyo Within Maeda Construction Co., Ltd. (72) Inventor Tsutomu Konno 1-1-1 Hama, Amagasaki-shi, Hyogo Kubota Technology Development Research In-house (72) Inventor Kazunori Tsujimoto 1-1-1, Hama, Amagasaki-shi, Hyogo Inside Kubota Technology Development Laboratory, Inc. (56) Reference JP-A-6-299796 (JP, A) JP-A-8-284595 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21D 11/04 E21D 11/08

Claims (4)

(57) [Claims] 1. A first segment main body (S1) and a second segment main body (S1) which are connected to an existing segment main body (S) while being moved in the longitudinal direction of the tunnel so as to be assembled adjacent to each other in the tunnel circumferential direction. S2), the first dovetail groove portion (M1) and the second dovetail groove portion (M1) are separately provided so as to face each other in a state where the both butting portions are abutted.
2) is provided, and a first enlarged edge portion (A1) that can be inserted into the first dovetail groove portion (M1) and a second enlarged edge portion (A2) that can be inserted into the second dovetail groove portion (M2). Connecting tool (R) provided on both sides,
The first enlarged edge portion (A1) is referred to as the first dovetail groove portion (M1).
The first segment body (S1)
To the existing segment main body (S) adjacent in the tunnel longitudinal direction, and then connect the second segment main body (S2) to the first segment main body (S1) side and the existing segment (S) side. The second enlarged edge portion (A2) is inserted into the inside of the second dovetail groove portion (M2) by pressing, and the connecting tool (R) further includes the first dovetail groove portion (M1) and the second dovetail groove portion (M1). By attracting the dovetail groove (M2), the first segment body (S1) and the second segment body (S)
2) A connecting portion structure of a tunnel segment for connecting with the first expanding edge portion (A1) and the first dovetail groove portion (M1).
Prior to being inserted into the first enlarged edge portion (A1), it is located on the inner side of the first dovetail groove portion (M1) of both end portions of the first enlarged edge portion (A1) along the insertion direction of the first enlarged edge portion (A1). A position fixing member (D) for locating the rear end portion (G) on the second segment body (S2) side inside the first dovetail groove portion (M1) is provided on the first dovetail groove portion (M1). Connection structure of the inserted tunnel segment. 2. The position fixing member (D) has a cross-sectional shape substantially equal to the cross-sectional shape of the first dovetail groove (M1) so that it can be inserted into the first dovetail groove (M1). ,
The tunnel segment connecting part structure according to claim 1, which is a member having a recess (D1) that abuts against the back end (G). 3. The position fixing member (D) is attached to the outside of the back side end portion (G), and the outer surface of the back side end portion (G) and the first dovetail groove portion (M1). 2. The tunnel segment connecting portion structure according to claim 1, which is a deformable member filled between the inner surface and the inner surface. 4. A first segment main body (S1) and a second segment main body (S1) which are connected to an existing segment main body (S) while being moved in the longitudinal direction of the tunnel and are assembled adjacent to each other in the circumferential direction of the tunnel. A first dovetail groove portion (M1) and a second dovetail groove portion (M2) are separately provided so as to oppose each of the abutting portions with S2) in a state where the abutting portions are abutted with each other. (M1) insertable first enlarged edge portion (A1), and the second dovetail groove portion (M2) insertable second enlarged edge portion (A2) on both sides, a connector (R),
The first enlarged edge portion (A1) is referred to as the first dovetail groove portion (M1).
The first segment body (S1)
To the existing segment main body (S) adjacent in the tunnel longitudinal direction, and then connect the second segment main body (S2) to the first segment main body (S1) side and the existing segment (S) side. The second enlarged edge portion (A2) is inserted into the inside of the second dovetail groove portion (M2) by pressing, and the connecting tool (R) further includes the first dovetail groove portion (M1) and the second dovetail groove portion (M1). By attracting the dovetail groove (M2), the first segment body (S1) and the second segment body (S)
2) is a connecting portion structure of a tunnel segment for connecting with the second segment along the insertion direction of the second enlarged edge portion (A2).
Of the both ends of the enlarged edge portion (A2), the back end portion (G) located on the back side of the second dovetail groove portion (M2) and the second
A connecting structure of a tunnel segment in which a chamfered portion (H) is provided on the opening side end portion (G1) of the dovetail groove portion (M2).