JP7429009B2 - segment - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act August 23, 2019 Published at the Japan Shield Segment Technology Association RC Segment Committee September 11, 2019 Published at Kubota Corporation Tokyo Head Office September 2019 Published on the 12th via email address “mizutani.koji@ad-hzmkg.co.jp”

The present invention relates to segments.

Patent Document 1 (Japanese Unexamined Patent Publication No. 9-60488) describes a segment ring having a plurality of segments. In the following, two segments adjacent in the circumferential direction will be referred to as a first segment and a second segment, respectively.

The first segment has a first segment body and a male coupling secured to the first segment body. The male connector has a first anchor portion and a first body portion. The first body portion has a columnar shape extending along the axial direction of the first segment body. The male connector is fixed to the first segment body by embedding the first anchor portion in the first segment body.

The second segment has a second segment body and a female coupling secured to the second segment body. The female connector has a second anchor portion and a second body portion. A fitting hole extending along the axial direction of the second segment body is formed in the second body portion. The female connector is fixed to the second segment body by embedding the second anchor portion in the second segment body. Note that a part of the side surface of the second main body part is covered by the second segment main body, and a buffer sheet is interposed between the side surface of the second anchor part and the second segment main body.

The first segment and the second segment are connected by inserting the first body into a fitting hole formed in the second body. Thereby, the first segment and the second segment are connected.

Japanese Patent Application Publication No. 9-60488

When connecting a male connector and a female connector, a tensile load may act between the male connector and the female connector. If the deformation of the second body portion is restrained by the second segment body, such a tensile load will cause the second segment body to crack. If the buffer sheet is interposed between the side surface of the second main body portion and the second segment main body, when a tensile load is applied between the male type connector and the female type connector, the second body portion Since the deformation is absorbed by the buffer sheet, the occurrence of cracks in the second segment main body is suppressed.

However, the side surface of the second main body portion is formed of a curved surface. Since the buffer sheet is attached to the side surface of the second main body in a bent state, the restoring force of the buffer sheet to return from the bent state to the flat state prevents the female connector from being buried in the second segment main body. In addition, there is a risk that it may peel off from the side surface of the second main body. In addition to embedding the female connector in the second segment, the buffer sheet may peel off from the side of the second main body when time elapses after the buffer sheet is attached due to transportation of the female connector, etc. There is a risk that this may occur. If the buffer sheet is peeled off, the deformation absorbing function described above will not be exhibited.

The present invention has been made in view of the problems of the prior art as described above. More specifically, the present invention provides a segment that can suppress peeling of a buffer sheet.

A segment according to one aspect of the present invention includes a segment body, a female joint member that includes a first side surface and has a cylindrical portion extending along the axial direction of the segment body, and is attached to the first side surface. A buffer sheet is provided. The female joint member is embedded in the segment body such that the first side surface is covered by the segment body with a buffer sheet interposed therebetween. A first slit extending along the axial direction is formed in the buffer sheet.

According to the segment according to one aspect of the present invention, peeling of the buffer sheet can be suppressed.

FIG. 3 is a front view of segment 100. 2 is a side view of the segment 100 in direction II of FIG. 1; FIG. 2 is a side view of the segment 100 in direction III of FIG. 1; FIG. FIG. 2 is a perspective view of a male connector 20. FIG. FIG. 3 is a front view of the female connector 30. FIG. 3 is a side view of the female connector 30. 7 is a sectional view taken along VII-VII in FIG. 6. FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 6. FIG. FIG. 3 is a cross-sectional view of the segment 100 in a cross-sectional view perpendicular to the axial direction of the segment body 10. FIG. FIG. 3 is a rear view of the female connector 30 with a buffer sheet 60 and a buffer sheet 70 attached thereto. 6 is a plan view of a buffer sheet 60. FIG. FIG. 3 is a side view of the female connector 30 to which a buffer sheet 60 is attached. FIG. 3 is a side view of a female connector 30 according to a modification. FIG. 3 is a front view of a female connector 30 according to a modified example. FIG. 7 is a plan view of a buffer sheet 60 used in a female connector 30 according to a modified example. FIG. 7 is a side view of a female connector 30 according to a modified example to which a buffer sheet 60 is attached. FIG. 2 is a schematic explanatory diagram when constructing a tunnel wall using segments 100. 18 is an enlarged view of area XVIII in FIG. 17. FIG.

Details of the embodiments will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference numerals, and overlapping descriptions will not be repeated.

(Segment configuration according to embodiment)
The configuration of a segment (hereinafter referred to as "segment 100") according to the embodiment will be described below.

<Schematic configuration>
FIG. 1 is a front view of segment 100. FIG. 2 is a side view of the segment 100 in direction II of FIG. FIG. 3 is a side view of the segment 100 in direction III of FIG. As shown in FIGS. 1 to 3, the segment 100 includes a segment body 10, a male connector 20, a female connector 30, an anchor bar 40, and an anchor bar 50 (not shown in FIGS. 1 to 3). , a buffer sheet 60, and a buffer sheet 70 (not shown in FIGS. 1 to 3). The number of male connectors 20 and the number of female connectors 30 are two each. The number of male connectors 20 and the number of female connectors 30 may each be one or four.

<Segment body 10>
The segment main body 10 has an arcuate shape. However, the shape of the segment body 10 is not limited to this. The segment main body 10 may have a rectangular shape, for example. The segment main body 10 is mainly made of concrete. The segment main body 10 has a first end surface 10a, a second end surface 10b, a third end surface 10c, and a fourth end surface 10d.

The first end surface 10a and the second end surface 10b constitute end surfaces of the segment main body 10 in the circumferential direction. The first end surface 10a and the second end surface 10b serve as connecting surfaces when connecting two circumferentially adjacent segments 100 (see FIG. 13). The third end surface 10c and the fourth end surface 10d constitute end surfaces of the segment body 10 in the axial direction.

A groove 10aa is formed in the first end surface 10a. The groove 10aa extends along the axial direction of the segment body 10 from the third end surface 10c toward the fourth end surface 10d. A groove 10ba is formed in the second end surface 10b. The groove 10ba extends along the axial direction of the segment 10 main body from the fourth end surface 10d toward the third end surface 10c.

<Male connector 20 and female connector 30>
The male connector 20 and the female connector 30 are made of, for example, ductile cast iron (spheroidal graphite cast iron).

The two male connectors 20 are arranged on the first end surface 10a and the second end surface 10b, respectively. The two female connectors 30 are arranged on the first end surface 10a and the second end surface 10b, respectively. The male connector 20 disposed on the first end surface 10a is located closer to the fourth end surface 10d in the axial direction of the segment body 10 than the female connector 30 disposed on the first end surface 10a. . The male connector 20 disposed on the second end surface 10b is located closer to the third end surface 10c in the axial direction of the segment body 10 than the female connector 30 disposed on the second end surface 10b. .

FIG. 4 is a perspective view of the male connector 20. As shown in FIG. 4, the male connector 20 has a base 21, a neck 22, and a tip 23. An anchor muscle 40 is inserted into the base 21. The anchor reinforcement 40 is formed of, for example, a steel bar for reinforced concrete. The neck portion 22 protrudes from the base portion 21 along the direction intersecting the first end surface 10a (second end surface 10b). The distal end portion 23 is disposed at the distal end of the neck portion 22 (the end of the neck portion 22 opposite to the base portion 21). The tip portion 23 has a columnar shape extending along the axial direction of the segment body 10. The cross-sectional area of the tip portion 23 in a cross section perpendicular to the axial direction of the segment body 10 may become smaller from one end toward the other end. The male connector 20 is constricted at the neck 22 .

The male connector 20 is fixed to the segment body 10 by partially embedding the anchor muscle 40, the base 21, and the neck 22 in the segment body 10. To put this in another perspective, the remainder of the neck 22 and the tip 23 are located outside the segment body 10.

FIG. 5 is a front view of the female connector 30. FIG. 6 is a side view of the female connector 30. As shown in FIGS. 5 and 6, the female connector 30 has a cylindrical portion 31, a base portion 32, and a neck portion 33.

The cylindrical portion 31 extends along the axial direction of the segment main body 10. The cylindrical portion 31 has a first end 31a and a second end 31b in the axial direction of the segment main body 10. The second end 31b is the end opposite to the first end 31a. The cylindrical portion 31 is open at a first end 31a and closed at a second end 31b. The outer diameter of the cylindrical portion 31 becomes smaller toward the first end 31a and the second end 31b. The outer diameter of the cylindrical portion 31 may be constant between the first end 31a and the second end 31b, or may vary between the first end 31a and the second end 31b.

The cylindrical portion 31 has an inner circumferential surface 31c, side surfaces 31d and 31e, and a distal end surface 31f. The inner circumferential surface 31c is formed of a curved surface. Note that "the inner circumferential surface 31c is composed of a curved surface" includes both cases where the inner circumferential surface 31c is composed only of a curved surface and cases where the inner circumferential surface 31c is composed of a curved surface and a flat surface. The side surfaces 31d and 31e face each other in a direction intersecting the axial direction of the segment main body 10. The side surface 31d and the side surface 31e extend from the first end 31a toward the second end 31b. The side surface 31d and the side surface 31e are formed of curved surfaces. Note that a case where the side surface 31d (side surface 31e) partially includes a flat surface is also included in "the side surface 31d (side surface 31e) is formed of a curved surface". More specifically, the side surfaces 31d and 31e are curved surfaces (side surfaces) that are convex toward the outside of the cylindrical portion 31 in a cross-sectional view perpendicular to the axial direction of the segment body 10 (see FIGS. 7 and 8). 31d (when the side surface 31e partially includes a plane, it is a substantially convex curved surface). The distal end surface 31f is located at the distal end of the female connector 30. The distal end surface 31f is configured, for example, by a flat surface. The tip surface 31f is continuous with the side surface 31d and the side surface 31e. The tip surface 31f extends from the first end 31a toward the second end 31b.

The cylindrical portion 31 has an insertion hole 31g formed therein. The insertion hole 31g extends inside the cylindrical portion 31 from the first end 31a toward the second end 31b. The insertion hole 31g is defined by an inner peripheral surface 31c. The cross-sectional area of the insertion hole 31g in a cross section perpendicular to the axial direction of the segment body 10 may become smaller from the first end 31a side to the second end 31b side.

An insertion slit 31h is formed in the cylindrical portion 31. The insertion slit 31h passes through the cylindrical portion 31 from the distal end surface 31f toward the inner circumferential surface 31c, and communicates with the insertion hole 31g. The insertion slit 31h extends from the first end 31a toward the second end 31b. The cylindrical portion 31 may have a protruding portion 31i protruding from the neck portion 33 on the second end 31b side. Since the cylindrical part 31 protrudes from the neck part 33 at the protrusion part 31i, it is not connected to the neck part 33 at the protrusion part 31i.

An anchor muscle 50 is inserted into the base 32. The anchor reinforcement 50 is formed of, for example, a steel bar for reinforced concrete. The neck portion 33 connects the cylindrical portion 31 and the base portion 32. The female connector 30 is constricted at the neck 33. The neck portion 33 has a first portion 33a and a second portion 33b. The first portion 33a is located closer to the first end 31a, and the second portion 33b is located closer to the second end 31b than the first portion 33a.

The neck portion 33 has a side surface 33c and a side surface 33d. The side surface 33c is continuous with the side surface 31d, and the side surface 33d is continuous with the side surface 31e. The side surface 33c and the side surface 33d extend along the axial direction of the segment main body 10. The side surface 33c and the side surface 33d are configured by, for example, a curved surface. More specifically, the side surface 33c and the side surface 33d are curved surfaces that are convex toward the inside of the neck portion 33 in a cross-sectional view perpendicular to the axial direction of the segment body 10 (see FIGS. 7 and 8).

FIG. 7 is a sectional view taken along VII-VII in FIG. 6. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. As shown in FIGS. 7 and 8, the first portion 33a has a width W1 in a cross-sectional view perpendicular to the axial direction of the segment main body 10. As shown in FIGS. The width W1 is the minimum value of the distance between the side surface 31d and the side surface 31e. The second portion 33b has a width W2 in a cross-sectional view orthogonal to the axial direction of the segment main body 10. The width W2 is the minimum value of the distance between the side surface 33c and the side surface 33d. Width W1 is larger than width W2. As a result, a step is formed on the side surface 33c and the side surface 33d at the boundary between the first portion 33a and the second portion 33b.

FIG. 9 is a cross-sectional view of the segment 100 taken in a cross-sectional view orthogonal to the axial direction of the segment body 10. As shown in FIG. 9, a buffer sheet 60 is attached to the side surface 31d, and a buffer sheet 70 is attached to the side surface 31e. The cylindrical portion 31 is embedded in the segment main body 10. The side surface 31d is covered by the segment main body 10 with a buffer sheet 60 interposed therebetween. The side surface 31e is covered by the segment main body 10 with a buffer sheet 70 interposed therebetween.

The cylindrical portion 31 does not need to be completely embedded in the segment main body 10. To put this from another perspective, a portion of the side surface 31d and the side surface 31e on the distal end surface 31f side may be exposed from the segment main body 10. The buffer sheet 60 does not need to be interposed between a portion of the side surface 31d on the distal end surface 31f side and the segment main body 10. The buffer sheet 70 may not be interposed between the segment main body 10 and a portion of the side surface 31e on the distal end surface 31f side. The tip surface 31f is exposed from the groove 10aa (groove 10ba).

The base portion 32, neck portion 33, and anchor muscle 50 are also embedded in the segment body 10. Thereby, the female connector 30 is fixed to the segment main body 10. The buffer sheet 60 may be attached across the side surface 31d and the side surface 33c, and the buffer sheet 70 may be attached across the side surface 31e and the side surface 33d. That is, the buffer sheet 60 may be interposed between the side surface 33c and the segment main body 10, and the buffer sheet 70 may be interposed between the side surface 33d and the segment main body 10. That is, the buffer sheet 60 and the buffer sheet 70 need only be attached to a location where the female connector 30 deforms when a tensile load is applied between the male connector 20 and the female connector 30.

Note that in the protruding portion 31i, the buffer sheet 60 (buffer sheet 70) is not attached across the side surface 31d and the side surface 33c (the side surface 31e and the side surface 33d). That is, in the protruding portion 31i, the buffer sheet 60 (buffer sheet 70) is attached only to the side surface 31d (side surface 31e). FIG. 10 is a rear view of the female connector 30 with the buffer sheet 60 and the buffer sheet 70 attached. As shown in FIG. 10, in the protrusion 31i, the buffer sheet 60 and the buffer sheet 70 are attached directly to the side surface 31d and the side surface 31e, respectively, to improve adhesion, so that the buffer sheet 60 is attached to the second side 60b side. In this case, it is preferable that the buffer sheet 70 not overlap with the buffer sheet 70. However, in the protruding portion 31i, the buffer sheet 60 may overlap the buffer sheet 70 on the second side 60b side.

As described above, since the distal end surface 31f is exposed from the groove 10aa (groove 10ba), the insertion slit 31h is exposed from the groove 10aa (groove 10ba). Moreover, in a front view seen from a direction perpendicular to the third end surface 10c (fourth end surface 10d), the insertion hole 31g is exposed to the groove 10aa (groove 10ba). As a result, the male connector 20 is slid relative to the female connector 30 along the axial direction of the segment main body 10 with the neck portion 22 and tip portion 23 inserted into the insertion slit 31h and the insertion hole 31g, respectively. can be done.

The buffer sheet 60 and the buffer sheet 70 are, for example, foamed polyethylene sheets. FIG. 11 is a plan view of the buffer sheet 60. FIG. 12 is a side view of the female connector 30 to which the buffer sheet 60 is attached. In FIG. 12, the buffer sheet 60 is indicated by a dotted line. As shown in FIGS. 11 and 12, the buffer sheet 60 has a rectangular shape. However, the shape of the buffer sheet 60 is not limited to this. The buffer sheet 60 may have a trapezoidal shape, for example.

The buffer sheet 60 has a first side 60a, a second side 60b, a third side 60c, and a fourth side 60d. The first side 60a and the second side 60b are along the axial direction of the segment main body 10. The second side 60b is closer to the base 32 than the first side 60a. More specifically, the second side 60b is located at the neck portion 33. The third side 60c and the fourth side 60d intersect in the axial direction of the segment main body 10. The fourth side 60d is closer to the first end 31a than the third side 60c. The third side 60c is located near the second end 31b, and the fourth side 60d is located near the first end 31a.

A first slit 61 is formed in the buffer sheet 60. The first slit 61 extends along the axial direction of the segment main body 10. The first slit 61 penetrates the buffer sheet 60 along the thickness direction. Note that the first slit 61 does not need to penetrate the buffer sheet 60 in the thickness direction. The first slit 61 may be divided into a plurality of parts (for example, a first part 61a and a second part 61b) in the axial direction of the segment main body 10. The first portion 61a and the second portion 61b are spaced apart from each other in the axial direction of the segment main body 10. Although this example shows a case where the number of divisions of the first slit 61 is two, the number of divisions of the first slit 61 is not limited to two. A plurality of first slits 61 may be formed at intervals along the direction from the first side 60a to the second side 60b. Note that the first slit 61 includes one located closer to the first side 60a than the second slit 62 and the third slit 63 (first slit 61c), and one located between the second slit 62 and the third slit 63. The first slit 61d may be arranged in the first slit 61d, and the first slit 61e may be connected to the second slit 62 or the third slit 63.

The buffer sheet 60 may have at least one vertical slit extending from the second side 60b toward the first side 60a. This vertical slit penetrates the buffer sheet 60 in the thickness direction. Note that the vertical slits do not need to penetrate the buffer sheet 60 in the thickness direction. The vertical slits include, for example, a second slit 62 and a third slit 63.

The second slit 62 is arranged along the boundary between the first portion 33a and the second portion 33b. The third slit 63 is arranged on the side surface 31d of the protrusion 31i. The second slit 62 is located closer to the fourth side 60d than the third slit 63.

The distance between the fourth side 60d and the second slit 62 in the axial direction of the segment body 10 is defined as distance L1, and the distance between the third side 60c and the third slit 63 in the axial direction of the segment body 10 is defined as distance L2. shall be. It is preferable that the distance L1 and the distance L2 are equal to each other.

Note that the buffer sheet 70 has the same shape as the buffer sheet 60, for example. Therefore, detailed explanation regarding the shape of the buffer sheet 70 will be omitted here. However, in the buffer sheet 70, the third side 60c corresponds to the fourth side 60d, and the fourth side 60d corresponds to the third side 60c.

<Modified example>
FIG. 13 is a side view of a female connector 30 according to a modified example. FIG. 14 is a front view of a female connector 30 according to a modified example. As shown in FIGS. 13 and 14, the female connector 30 according to the modified example does not have a base 32 and a neck 33. The female connector 30 according to the modification includes an anchor portion 34 , and the anchor portion 34 is connected to the cylindrical portion 31 . The anchor portion 34 extends in a direction intersecting the axial direction of the segment body 10 (direction from the first end 31a to the second end 31b). The anchor portion 34 is embedded in the segment main body 10. In the example shown in FIGS. 13 and 14, the number of anchor parts 34 is two, but the number of anchor parts 34 is not limited to this. The two anchor parts 34 may be connected to each other on the opposite side to the cylindrical part 31.

The female connector 30 according to the modified example further includes ribs 35. The rib 35 is arranged so as to straddle the anchor portion 34 and the side surface 31d. A step is formed at the boundary between the rib 35 and the side surface 31d. The female connector 30 according to the modification may further include ribs 36. The rib 36 is arranged so as to straddle the anchor portion 34 and the side surface 31e. A step is also formed at the boundary between the rib 36 and the side surface 31e.

FIG. 15 is a plan view of a buffer sheet 60 used in a female connector 30 according to a modified example. FIG. 16 is a side view of a female connector 30 according to a modified example to which a buffer sheet 60 is attached. As shown in FIGS. 15 and 16, the vertical slits of the buffer sheet 60 include a fourth slit 64. The fourth slit 64 is formed along the boundary between the side surface 31d and the rib 35. The fourth slit 64 makes it easier to attach the buffer sheet 60 along the step between the rib 35 and the side surface 31d.

<Assembling segment 100>
FIG. 17 is a schematic explanatory diagram when constructing a tunnel wall using the segments 100. FIG. 18 is an enlarged view of area XVIII in FIG. 17. As shown in FIGS. 15 and 16, when a tunnel is dug using the shield method, the walls of the tunnel are constructed by sequentially arranging segment rings 200 from the face side to the tunnel entrance side.

Segment ring 200 is constructed by connecting multiple segments 100. The segment ring 200 is constructed by sliding a new segment 100 (hereinafter referred to as "segment 100a") against the existing segment 100 (hereinafter referred to as "segment 100b") from the face side toward the mine entrance side. be done.

More specifically, by sliding the segment 100a relative to the segment 100b, the tip 23 of the male coupling 20 on the first end surface 10a of the segment 100a is connected to the female coupling on the second end surface 10b of the segment 100b. At the same time, the tip 23 of the male connector 20 on the second end surface 10b of the segment 100b is inserted into the insertion hole 31g of the female connector 30 on the first end surface 10a of the segment 100a. This will connect segment 100a and segment 100b. By repeating this operation, the segment ring 200 is completed.

(Effects of segments according to embodiment)
The effects of segment 100 will be explained below.

When connecting segment 100a to segment 100b, a tensile load may be applied between male connector 20 and female connector 30. Such a tensile load may cause cracks to occur in the segment body 10 if the deformation of the cylindrical portion 31 is restrained by the segment body 10.

In the segment 100, the side surface 31d (side surface 31e) is covered with the segment body 10 with the buffer sheet 60 (buffer sheet 70) interposed, so the cylindrical portion 31 is deformed without being restrained by the segment body 10. Is possible. Therefore, in the segment 100, the deformation of the cylindrical portion 31 when the above-described tensile load occurs is absorbed by the buffer sheet 60 (buffer sheet 70), and the segment main body 10 is less likely to crack.

The female connector 30 is embedded in the segment body 10 with the buffer sheet 60 (buffer sheet 70) attached to the side surface 31d (side surface 31e). Since the side surface 31d (side surface 31e) is formed of a curved surface, when it is attached to the side surface 31d (side surface 31e) without forming the first slit 61 in the buffer sheet 60 (buffer sheet 70), the buffer sheet 60 (buffer sheet 70) The buffer sheet 60 (buffer sheet 70) once attached may peel off from the side surface 31d (side surface 31e) due to the restoring force that causes the sheet 70) to return from a bent state to a flat state. If the buffer sheet 60 (buffer sheet 70) is peeled off, the deformation absorbing function described above will not be exhibited.

In the segment 100, since the first slit 61 is formed in the buffer sheet 60 (buffer sheet 70), a restoring force acts on the buffer sheet 60 (buffer sheet 70) to return from a bent state to a flat state. As a result, the buffer sheet 60 (buffer sheet 70) becomes difficult to peel off from the side surface 31d (side surface 31e).

In the segment 100, when the first slit 61 is formed long along the axial direction of the segment body 10, when the female connector 30 is buried in the segment body 10, the concrete constituting the segment body 10 is , it becomes easy to enter between the first slits 61. As a result, the side surface 31d (side surface 31e) comes into direct contact with the segment main body 10, and the deformation absorbing function of the buffer sheet 60 (buffer sheet 70) may be reduced.

On the other hand, if the first slit 61 is divided into a plurality of parts spaced apart from each other in the axial direction of the segment main body 10, the length of each part constituting the first slit 61 becomes shorter. When embedding the female connector 30 in the segment body 10, the concrete forming the segment body 10 becomes difficult to enter between the first slits 61.

In the segment 100, the outer diameter of the cylindrical portion 31 may change between the first end 31a and the second end 31b. In this case, it is difficult to attach the buffer sheet 60 (buffer sheet 70) along the side surface 31d (side surface 31e). However, if a vertical slit is formed in the buffer sheet 60 (buffer sheet 70), even if the outer diameter of the cylindrical portion 31 changes between the first end 31a and the second end 31b, the buffer sheet 60 (Buffer sheet 70) can be easily pasted along side surface 31d (side surface 31e).

In the segment 100, since a step is formed on the side surface 33c (side surface 33d) at the boundary between the first portion 33a and the second portion 33b, the buffer sheet 60 (buffer sheet 70) is pasted along the step. It's hard to do. However, when the second slit 62 is formed in the buffer sheet 60 (buffer sheet 70), even if there is a step on the side surface 33c (side surface 33d) at the boundary between the first part 33a and the second part 33b, the buffer It is easy to attach the sheet 60 (buffer sheet 70) along the level difference.

The cylindrical part 31 is connected to the neck part 33 at parts other than the protruding part 31i, but is not connected to the neck part 33 at the protruding part 31i, so the buffer sheet 60 (buffer sheet 70) is connected to the side surface 31d ( It is difficult to paste along the side surface 31e). However, when the third slit 63 is formed in the buffer sheet 60 (buffer sheet 70), it becomes easier to attach the buffer sheet 60 (buffer sheet 70) along the side surface 31d (side surface 31e) on the protrusion 31i. .

When the distance L1 and the distance L2 are equal to each other, it is possible to use the same buffer sheet (buffer sheet 60) attached to the side surface 31d and the same buffer sheet (buffer sheet 70) attached to the side surface 31e.

Although the embodiments of the present invention have been described above, the embodiments described above can be modified in various ways. Moreover, the scope of the present invention is not limited to the above-described embodiments. The scope of the present invention is indicated by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

10 segment main body, 10a first end surface, 10aa groove, 10b second end surface, 10ba groove, 10c third end surface, 10d fourth end surface, 20 male connector, 21 base, 22 neck, 23 tip, 30 female connector Tool, 31 Cylindrical portion, 31a First end, 31b Second end, 31c Inner peripheral surface, 31d, 31e Side surface, 31f Tip surface, 31g Insertion hole, 31h Insertion slit, 31i Projection, 32 Base, 33 Neck, 33a First part, 33b Second part, 33c, 33d Side surface, 34 Anchor part, 35, 36 Rib, 40, 50 Anchor line, 60 Buffer sheet, 60a First side, 60b Second side, 60c Third side, 60d 4 sides, 61, 61c, 61d, 61e first slit, 61a first part, 61b second part, 62 second slit, 63 third slit, 64 fourth slit, 70 buffer sheet, 100 segment, 100a, 100b segment , 200 segment ring, L1, L2 distance, W1, W2 width.

Claims (7)

a segment body;
a female connector having a cylindrical portion including a first side surface configured with a curved surface and extending along the axial direction of the segment body;
and a buffer sheet affixed to the first side surface,
The female connector is embedded in the segment main body such that the first side surface is covered with the segment main body with the buffer sheet interposed therebetween;
A segment in which a first slit extending along the axial direction is formed in the buffer sheet. The segment according to claim 1, wherein the first slit is divided into a plurality of parts in the axial direction. The female connector has a base and a neck connecting the cylindrical part and the base,
The cylindrical portion includes, in the axial direction, a first end and a second end that is an end opposite to the first end,
The buffer sheet has a first side along the axial direction, a second side that runs along the axial direction and is closer to the base than the first side, and a second side that intersects with the axial direction. and a fourth side that intersects with the axial direction and is closer to the first end than the third side,
The segment according to claim 1 or 2, wherein the buffer sheet has at least one vertical slit extending from the second side toward the first side. The neck includes a second side surface that is continuous with the first side surface,
The buffer sheet is attached to the first side surface and the second side surface,
The neck portion includes a first portion located on the first end side and a second portion located on the second end side from the first portion,
The width of the first portion is larger than the width of the second portion in a cross-sectional view perpendicular to the axial direction, so that the second portion is located at the boundary between the first portion and the second portion. A step is formed on the side,
4. The segment of claim 3, wherein the at least one vertical slit includes a second slit located along the boundary. The cylindrical portion has a protrusion protruding from the neck portion on the second end side,
5. The segment of claim 4, wherein the at least one longitudinal slit includes a third slit located on the first side of the protrusion. The segment according to claim 5, wherein a distance between the second slit and the fourth side in the axial direction is equal to a distance between the third slit and the third side in the axial direction. The female connector has an anchor part connected to the cylindrical part, and a rib disposed across the anchor part and the first side surface,
A step is formed at the boundary between the rib and the first side surface,
The segment according to claim 1, wherein the buffer sheet is formed with a fourth slit arranged along the boundary.

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