JP7440437B2 - segment fittings - Google Patents

Description

The present invention relates to a segment joint.

In recent years, so-called one-pass type segment joints have been applied to segment joints for concrete-based segments. Here, the concrete segment includes an RC (Reinforced Concrete) segment and a synthetic segment in which a steel segment and concrete are synthesized.
One-pass type segment joints use products that combine regular cast iron members and anchor reinforcing bars (cone connector joints), but they have various problems, such as the following.
First, product costs tend to be high because there are no substitutes.
In addition, in this cone connector joint, the specifications and dimensions of the anchor reinforcement for fixing it to the concrete are generally fixed, and as a result of this, the rigidity (spring constant) and proof strength of the segment joint are fixed, so the design The degree of freedom tends to decrease.
In addition, because the anchor bars for fixing concrete are long, they tend to be subject to restrictions in terms of design and manufacturing.
Furthermore, since the male and female joining portions of the joint body are semicircular, they tend to rotate easily, and the segments tend to open during or after assembly. When the segment joint rotates, a bending load acts on the joint body, which may reduce the proof strength of the joint body, which is designed as a tensile member.
Furthermore, since the scope of application is limited to RC segments, it cannot be applied to synthetic segments.
Based on the above, it is desirable to develop a segment joint that can reduce manufacturing costs, has a high degree of design freedom, is less subject to restrictions in design and manufacturing, is less likely to cause openings, and can be applied to both RC segments and synthetic segments. It is rare.

Here, in Patent Document 1, segments that are adjacent in the circumferential direction of the tunnel are connected to each other using a connector by abutting the joint surfaces of the segment bodies made of reinforced concrete, so that the inner circumferential surface or the outer circumferential surface of the segment bodies are aligned in the circumferential direction of the tunnel. an engagement metal member formed on a curved surface that curves along the curved surface, a joint surface formed on an inclined surface that is inclined with respect to the normal line of the curved surface, and a coupling member with an engaging portion facing the joint surface side, and a segment. The segments are moved relative to each other in the longitudinal direction of the tunnel, and the engagement alloys are engaged with each other to connect each other, and the engagement direction of the engagement alloys is aligned with respect to the joint surface. A tunnel segment connection structure is disclosed in which an engagement alloy is fixed to a segment body so as to be inclined in a direction along a curved surface rather than in a direction perpendicular to the surface.

Japanese Patent Application Publication No. 2009-19460

According to the tunnel segment connection structure described in Patent Document 1, since the interconnecting devices are fixed to the segments by anchor bars, the long length of the anchor bars may cause interference with other structural members. Furthermore, since steel bars of different diameters are generally used for this anchor reinforcement, its yield strength is regulated, and it is not possible to set the yield strength and rigidity in a variety of ways. Therefore, as described above, it is susceptible to restrictions in terms of design and manufacturing, and the rigidity (spring constant) and yield strength of the segment joints are fixed, resulting in a problem that the degree of freedom in design is reduced. Furthermore, since the joint portion of the connector is semicircular, it is easy to rotate, and the segments are likely to open during or after assembly.

The present invention aims to provide a segment joint that can reduce manufacturing costs, has a high degree of design freedom, is less subject to restrictions in design and manufacturing, is less likely to open up, and can be applied to both RC segments and synthetic segments. The purpose is

In order to achieve the above object, one aspect of the segment joint according to the present invention is as follows:
A first segment and a second segment, which are concrete segments that are adjacent to each other in the circumferential direction of the tunnel, each have a first joint surface and a second joint surface, and a male joint provided on the first joint surface and a second joint surface. A segment joint in which a female joint provided on two joint surfaces is connected,
The male joint is
a male metal fitting protruding from the first joint surface;
a first anchor attached to the base of the male hardware and formed by a headed bolt;
The female joint is
a female hardware disposed inside the second segment relative to the second joint surface;
a second anchor attached to the base of the female joint and formed by a headed bolt;
The male metal fitting is a T-shaped metal fitting having a T-shape in side view,
The female metal fitting is provided with a T-shaped groove having a T-shape in side view, with which the T-shaped metal fitting engages.
The male joint and the female joint are arranged in a straight line when the T-shaped metal fitting is engaged with the T-shaped groove.

According to this aspect, both the male joint provided on the first joint surface of the first segment and the female joint provided on the second joint surface of the second segment, which are connected to each other, are long. Instead of anchor bars, the first and second anchors of the male and female joints are anchored to the concrete forming the segments via anchors (first anchor and second anchor) formed by headed bolts. The length, diameter, strength classification, etc. of the two anchors can be changed freely, and the rigidity (spring constant) and proof strength of the segment joints can be changed in a variety of ways, making it possible to increase the degree of design freedom. In addition, because the first and second anchors are formed with headed bolts, their length is much shorter than that of anchor bars, and yet they have sufficient anchorage strength with the concrete (the bearing force due to the head nuts). Since the resultant force of the frictional force on the side of the bolt can be obtained, there are fewer restrictions in terms of design and manufacturing.
Furthermore, the male hardware is a T-shaped hardware that is T-shaped when viewed from the side, the female hardware is provided with a T-shaped groove that is T-shaped when viewed from the side, and the T-shaped hardware is engaged with the T-shaped groove. Relative rotation of the male metal fitting and the female metal fitting in the segment joint can be suppressed, thereby making it possible to suppress the opening of the segment joint.
In addition, this embodiment can be applied to both RC segments and synthetic segments, and can be used as an alternative to conventionally widely used cone connector joints that combine standard cast iron members and anchor reinforcing bars. Since the female joint can be machined and has an anchor formed by a headed bolt, it is also possible to reduce manufacturing costs.
Here, when the T-shaped metal fitting is engaged with the T-shaped groove, the male joint and the female joint are arranged in a straight line, so that the load transmission performance from one segment to the other segment is improved. This results in a segment joint with high connection strength.

In this aspect, a male joint and a female joint are provided on the first joint surface of the first segment, and a female joint is also provided on the second joint surface of the second segment at positions corresponding to the male joint and female joint on the first joint surface. This also includes forms in which a male joint is provided. For example, a configuration in which a plurality of male joints are provided on the first joint surface and a female joint is provided at a position corresponding to each male joint on the second joint surface (therefore, a plurality of female joints are provided), , a configuration in which a plurality of female joints are provided on the first joint surface and a male joint is provided at a position corresponding to each female joint on the second joint surface is also included. An example of a segment joint with more stability and higher connection strength is one in which both the first joint surface and the second joint surface have male and female joints, and the corresponding male and female joints are engaged with each other. It will be done.
The segment joint structure of this embodiment can be applied to a segment joint between a B segment and a K segment, a segment joint between a B segment and an A segment, a segment joint between A segments, and the like.

Further, in another aspect of the segment joint according to the present invention,
The second joint surface is provided with a guide groove that extends in the longitudinal direction of the second joint surface and into which the male metal fitting can slide.
The female metal fitting is disposed inside the guide groove so as to be freely engageable with the male metal fitting.

According to this aspect, the second joint surface is provided with a guide groove that extends in the longitudinal direction of the second joint surface and into which the male metal fitting can slide, thereby forming a one-pass type segment joint. I can do it.

Further, in another aspect of the segment joint according to the present invention,
The T-shaped hardware includes a central shaft portion and an overhanging portion extending above and below the shaft portion at the tip of the shaft portion,
In the T-shaped hardware, the width of the protruding portion in a plan view changes in a tapered shape in the sliding direction of sliding in the guide groove,
The T-shaped groove has a shape in plan view that is complementary to the shape in plan view of the T-shaped metal piece,
In a state where the T-shaped metal fitting is engaged with the T-shaped groove, both engaging surfaces are in wedge-shaped surface contact.

According to this aspect, the T-shaped hardware includes a central shaft portion and an overhang portion that overhangs above and below at the tip of the shaft portion, and the width of the overhang portion in plan view changes in a tapered shape in the sliding direction in the guide groove. However, when the T-shaped metal fitting is engaged with the T-shaped groove, both engagement surfaces are in wedge-shaped surface contact, which together with the fact that the male and female fittings are arranged in a straight line, As a result, a segment joint with high connection strength is formed.

Further, other aspects of the segment joint according to the present invention include:
The concrete-based segment is a composite segment having a steel shell and a concrete body inside the steel shell, and the first segment and the second segment each include a first joint plate and a second joint plate, The first joint surface and the second joint surface are joint surfaces provided by the first joint plate and the second joint plate, respectively,
The male joint further includes a first steel bracket fixed to the steel shell of the first segment, and the first steel bracket and the male hardware are connected via the first anchor,
The female joint further includes a second steel bracket fixed to the steel shell of the second segment, and the second steel bracket and the female hardware are connected via the second anchor. It is characterized by

According to this aspect, the first segment and the second segment are composite segments, and the first steel bracket fixed to the steel shell of the first segment and the male hardware are connected via the first anchor. A male joint is formed by forming a male joint, and a female joint is formed by connecting a second steel bracket fixed to the steel shell of the second segment and a female hardware via a second anchor, thereby forming a composite segment. A one-pass segment joint can be realized.

Further, other aspects of the segment joint according to the present invention include:
In the T-shaped hardware, among the widths in plan view of the overhanging part that changes in a tapered shape, an intermediate width: D _mid between the maximum width: D _max and the minimum width: D _min , and the axis of the overhanging part. It is characterized in that the ratio of the overhang length from the part to L: D _mid /L is in the range of 100% or more.

According to this aspect, in a T-shaped metal fitting, the width in a plan view of the overhanging part that changes in a tapered shape is _an intermediate width between the maximum width: D _max and the minimum width: D _min , and the width from the shaft of the overhanging part. By setting the ratio of the overhang length to L: D _mid /L in the range of 100% or more, the overhang part of the T-shaped metal fitting does not become a weak part of the structure and has the overhang length necessary for engagement. The overall rigidity of the T-shaped hardware including the overhanging portion can be increased, and the T-shaped hardware can be regarded as a rigid body as a whole.

Further, other aspects of the segment joint according to the present invention include:
It is characterized in that the D _mid /L is in a range of 150% or more.

According to this aspect, since D _mid /L is in the range of 150% or more, the overall rigidity of the T-shaped metal fitting including the overhanging portion is further improved while the overhanging portion has the overhanging length necessary for engagement. can be increased. Here, according to the joint bending test conducted by the present inventors, one of the upper and lower overhangs of the shaft of the T-shaped metal fitting is on the compression side and the other is on the tension side, but D _mid /L is 150% or more. It has been proven that within this range, the load can be borne as evenly as possible on both the compression side and tension side overhangs. By having the upper and lower overhanging portions bear the load as evenly as possible, it is possible to suppress a decrease in the yield strength of the male joint.

Further, other aspects of the segment joint according to the present invention include:
In the T-shaped hardware, among the widths in plan view of the overhanging part that changes in a tapered shape, _an intermediate width between the maximum width: D _max and the minimum width: D _min , and the width of the shaft part: B. The ratio of D _mid /B is in the range of 80% or more and 120% or less.

According to this aspect, the ratio D mid /B between the intermediate width D _mid and the shaft width B in the T- _shaped metal fitting is in the range of 80% or more and 120% or less, so that a load above a certain level is not applied. When the load is applied, the upper and lower overhanging portions can bear the load as evenly as possible, and a decrease in proof strength of the male joint can be suppressed.

According to the segment joint of the present invention, the manufacturing cost can be reduced, the degree of freedom in design is high, it is difficult to be subject to restrictions during design and manufacturing, the opening is difficult to occur, and the segment joint can be applied to both RC segments and synthetic segments. can be provided.

It is a perspective view explaining an example of the formation method of the segment joint concerning an embodiment. FIG. 2 is a cross-sectional view illustrating an example of a method for forming a segment joint according to an embodiment. It is a longitudinal cross-sectional view explaining an example of a segment joint concerning an embodiment. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3 and illustrating an example of the segment joint according to the embodiment. FIG. It is a schematic diagram explaining a joint bending test. (a) is a side view illustrating the mounting position of the strain gauge attached to the male metal fitting in the joint bending test, and (b) is a view taken in the direction of arrow b in (a), showing the mounting position of the strain gauge. It is a top view explaining a position. A T-shaped hardware in which the ratio of the intermediate width of the tapered overhanging portion in plan view: D _mid and the length of the overhanging portion from the shaft portion: L: D _mid /L is approximately 100%. It is a figure which shows the joint bending test result when applying. A T-shaped hardware in which the ratio of the intermediate width in plan view of the tapered overhanging portion: D _mid to the length of the overhanging portion from the shaft portion: L: D _mid /L is approximately 150%. It is a figure which shows the joint bending test result when applying.

Hereinafter, a segment joint according to an embodiment will be described with reference to the accompanying drawings along with a method for forming the same. Note that in this specification and the drawings, substantially the same constituent elements may be given the same reference numerals to omit redundant explanation.

[Segment joint according to embodiment]
First, an example of a segment joint according to an embodiment and a method for forming the same will be described with reference to FIGS. 1 to 4. Here, FIGS. 1 and 2 are a perspective view and a cross-sectional view, respectively, illustrating an example of a method for forming a segment joint according to an embodiment. Further, FIG. 3 is a longitudinal sectional view illustrating an example of the segment joint according to the embodiment, and FIG. 4 is a view taken along the line IV-IV in FIG. 3, illustrating an example of the segment joint according to the embodiment. FIG.

The illustrated first segment 10A and second segment 10B are, for example, a K segment and a B segment that are adjacent to each other in the circumferential direction of the tunnel, and the K segment 10A is fitted into the left and right B segments 10B in the X1 direction in the longitudinal direction of the tunnel. As a result, the segment joint 60 (see FIGS. 3 and 4) according to the embodiment is formed. Note that the first segment may be another B segment or A segment, and the second segment may also be another K segment or A segment.

The first segment 10A and the second segment 10B are both synthetic segments, and consist of a pair of main girders 21, a pair of first and second joint plates 22A and 22B, and a skin plate 23 welded to these. It is formed by filling the inside of a steel shell with a concrete body 50 (see FIGS. 3 and 4). Note that the first segment and the second segment may also be RC segments.

One first joint plate 22A of the first segment 10A includes a male joint 30 near the end on the near side in FIG. 1, and a female joint 40 near the end on the back side in FIG. On the other hand, the second joint plate 22B of the second segment 10B that comes into contact with the first joint plate 22A is provided with a similar female joint 40 (not shown) at a position where it engages with the male joint 30 of the first segment 10A, A similar male joint 30 (not shown) is provided at a position where it engages with the female joint 40 of the first segment 10A. Further, the other second joint plate 22B of the first segment 10A is provided with a female joint 40 (not shown) near the end on the front side in FIG. 1, for example, opposite to the first joint plate 22A. A male joint 30 (not shown) is provided near the end on the back side of 1.

In the first joint plate 22A of the first segment 10A shown in FIG. A guide groove 24 is shown into which a male metal fitting 33 (not shown) protruding from the joint plate 22B can fit and slide. On the other hand, the second joint plate 22B of the second segment 10B shown in FIG. 1 shows a guide groove 24 into which a male metal fitting 33 protruding from the first joint plate 22A of the first segment 10A can fit and slide.

As shown in FIG. 2, the male joint 30 includes a first steel bracket 31 fixed to the main girder 21, which is a steel shell of the first segment 10A, by welding or bolting, a male metal fitting 33, and a first It has a plurality of (two in the illustrated example) first anchors 32 that connect the steel bracket 31 and the male hardware 33.

The first anchor 32 is formed by a headed bolt. In addition, as shown in FIGS. 2 and 3, the first steel bracket 31 includes two steel horizontal members 31a that are trapezoidal in plan view, and a steel vertical member that connects these two steel horizontal members 31a. 31b, a bolt hole 31c into which the first anchor 32 is screwed is opened in the steel vertical member 31b, and the head of the headed bolt 32 is engaged with the back surface of the steel vertical member 31b. It protrudes from the second segment side in its posture.

A T-shaped metal fitting 33 is bolted to the two headed bolts 32. As shown in FIGS. 2 and 3, the T-shaped hardware 33 includes a threaded portion 35 into which the headed bolt 32 is threaded, and a shaft portion 36 that protrudes from the end surface of the threaded portion 35 toward the second segment. It has a base portion 34 and an overhang portion 37 that extends above and below the shaft portion 36 at the tip of the shaft portion 36.

As clearly shown in FIG. 2, the end side of the overhanging portion 37 on the second segment side in plan view is parallel to the first joint surface 22a of the first segment 10A and the second joint surface 22b of the second segment 10B. The opposite end side has a tapered linear shape so that the width of the overhanging portion 37 becomes narrower linearly toward the X1 direction, which is the insertion direction of the first segment 10A.

As shown in FIG. 2, the width of the overhanging portion 37 in plan view is the maximum width: D _max on the main girder side, the minimum width: D _min on the opposite side, and the width at the center position in the longitudinal direction of the overhanging portion 37 is the middle width. Width: D _mid ((D _max + D _min )/2).

On the other hand, as shown in FIG. 2, the female joint 40 includes a second steel bracket 41 fixed to the main girder 21, which is the steel shell of the second segment 10B, by welding or bolting, and a female hardware 43. It has a plurality of (two in the illustrated example) second anchors 42 that connect the second steel bracket 41 and the female hardware 43.

The second anchor 42 is also formed by a headed bolt like the first anchor 32. Similarly to the first steel bracket 31, the second steel bracket 41 also includes two steel cross members 41a that are trapezoidal in plan view, and these two steel cross members 41a, as shown in FIGS. 2 and 3. It is formed by a steel vertical member 41b that connects the horizontal member 41a, and a bolt hole 41c into which the second anchor 42 is screwed is opened in the steel vertical member 41b, and a bolt hole 41c with a head is formed on the back side of the steel vertical member 41b. The head of the bolt 42 protrudes toward the first segment in an engaged position.

A female metal fitting 43 is bolted to the two headed bolts 42. As shown in FIGS. 2 and 3, the female hardware 43 has a base 44 into which the headed bolt 42 is screwed, and a female hardware 43 that is opened at the end of the base 44 and is connected above and below to a part of the shaft 36 of the T-shaped hardware 33. It has a T-shaped groove 45 with which the overhanging portion 37 engages.

As clearly shown in FIG. 2, the T-shaped groove 45 has a shape that is complementary to the upper and lower overhanging parts 37 and a part of the shaft part 36 of the T-shaped metal fitting 33 whose width changes in plan view. . Therefore, as shown in FIG. 2, when the first segment 10A is fitted in the X2 direction along the guide groove 24 provided on the second joint surface 22b of the second segment 10B, as shown in FIG. Then, the T-shaped metal fitting 33 engages with the T-shaped groove 45, and the engaging surfaces of both engage in wedge-shaped surface contact, thereby forming a segment joint 60.

Further, as shown in FIG. 3, when the T-shaped metal fitting 33 is engaged with the T-shaped groove 45, the male joint 30 and the female joint 40 are arranged in a straight line along the straight line L.

In this way, the male metal fitting 33 is a T-shaped metal fitting having a T-shape when viewed from the side, the female metal fitting 43 is provided with a T-shaped groove 45 having a T-shape when viewed from the side, and the T-shaped metal fitting 33 is engaged with the T-shaped groove 45. Furthermore, since both engagement surfaces are in wedge-shaped surface contact, relative rotation of the male metal fittings 33 and female metal fittings 43 in the segment joint 60 can be suppressed, and as a result, the opening of the segment joint 60 can be reduced. is suppressed.

In addition, since the male joint 30 and the female joint 40 are arranged in a straight line, load transmission performance from one segment (for example, the first segment 10A) to the other segment (for example, the second segment 10B) is good. This linear arrangement and the engagement between the T-shaped metal fittings 33 and the T-shaped grooves 45 combine to form the segment joint 60 with high connection strength.

Furthermore, the male joint 30 (and female joint 40) provided on the first joint surface 22a of the first segment 10A, and the female joint 40 (and male joint 40) provided on the second joint surface 22b of the second segment 10B. 30) are all anchored to the concrete body 50 forming the composite segment via the first anchor 32 and the second anchor 42 formed by headed bolts instead of the long anchor reinforcement, Although their lengths are much shorter than those of long anchor bars, sufficient fixation strength can be obtained between them and the concrete body 50, so that they are less subject to restrictions in terms of design and production. Note that, unlike the illustrated example, when the segment is an RC segment, the length, diameter, strength classification, etc. of the applied first anchor 32 and second anchor 42 can be freely changed, and the rigidity (spring Since the constant) and proof stress can be changed in a variety of ways, the degree of freedom in design can be further increased.

Further, the first segment 10A and the second segment 10B are composite segments, and the first steel bracket 31 and male hardware 33 fixed to the main girder 21, which is the steel shell of the first segment 10A, are connected to the first anchor 32. The male joint 30 is formed by being connected via the second anchor 42, and the second steel bracket 41 and female hardware 43, which are fixed to the main girder 21 which is the steel shell of the second segment 10B, are connected via the second anchor 42. By connecting to form the female joint 40, a one-pass type segment joint 60 in the composite segment can be realized.

[Joint bending test and its results]
Next, a joint bending test conducted by the present inventors and its results will be described with reference to FIGS. 5 to 8. Here, FIG. 5 is a schematic diagram illustrating a joint bending test.

As shown in Fig. 5, in this joint bending test, two arc-shaped full-scale segments were connected via the segment joint according to the embodiment, and the leg of each segment was placed on a roller support. Made the body. For this test specimen, half (P/2) of the predetermined load P is applied to the two points on the left and right of the center segment joint, and a male joint is formed to form a segment joint while creating an opening in the segment joint. and various strengths of the female joint were measured.

In addition, in this joint bending test, we used a male joint with two types of T-shaped hardware and a female joint with a T-shaped groove that engages with the male joint, and two types of segment joints with male and female joints. A joint bending test was conducted on the specimen.

FIG. 6(a) is a side view illustrating the mounting position of the strain gauge attached to the male metal fitting in the joint bending test, and FIG. 6(b) is a view in the b direction of FIG. 6(a). FIG. 3 is a plan view illustrating the mounting position of strain gauges. As shown in FIG. 6(a), in the T-shaped hardware, the length of the overhang extending from the shaft is indicated by L, and the width of the shaft is indicated by B.

Table 1 below shows the maximum width: D _max , the minimum width: D _min , the intermediate width: D _mid , and the overhang of the T-shaped metal fittings forming each test specimen (first test specimen, second test specimen). Length: L, ratio of each width to overhang length: D/L. In addition, load-strain relationship graphs, which are the test results for each test piece, are shown in FIGS. 7 and 8. Here, FIG. 7 is a diagram showing the joint bending _{test results of the first test piece to which a T-type metal fitting with D mid /} L of about 100% is applied, and FIG. It is a figure which shows the joint bending test result of the 2nd test piece to which the T-type metal fitting of 2 was applied. In addition, both the vertical and horizontal axes in Figures 7 and 8 normalize the measured load and strain based on the standard values, and the joint long-term allowable load and joint yield load are also normalized based on the standard values. It is normalized.

From FIGS. 7 and 8, it can be seen that both the first test specimen and the second test specimen bear the load in the same manner below and above the overhang. Therefore, in both the first test specimen where D _mid /L is in the range of 100% or more, and the second test specimen where D _mid /L is in the range of 150% or more, the upper and lower parts of the overhang are as evenly distributed as possible. It has been proven that it can bear the load. This result shows that the overhanging part of the T-shaped metal fitting does not become a structurally weak part, and that the T-shaped metal fitting can be regarded as a rigid body as a whole, even though it has the overhanging part necessary for engagement. By having the overhanging portions bear the load as evenly as possible, it becomes possible to suppress a decrease in the yield strength of the male joint.

Moreover, in FIG. 8, compared to FIG. 7, the behavior of the upper and lower portions of the overhang shows a more similar tendency, which indicates that the load is more evenly borne.

From the results of this experiment, in the T-shaped hardware, among the widths in plan view of the overhanging part that changes in a tapered shape, the intermediate width: D _mid between the maximum width: D _max and the minimum width: D _min , and the axis of the overhanging part. It has been demonstrated that the ratio of the overhanging length from the part to L: D _mid /L is preferably in a range of 100% or more, and it is desirable that D _mid /L is in a range of 150% or more.

In addition, in this experiment, the width B of the shaft part of the T-shaped metal piece was 19 mm, so in the first and second test specimens, the intermediate width in plan view of the overhanging part that changes in a tapered shape. It can be seen that the ratio: D _mid /B of :D _mid and the width of the shaft part: B is 80% or more.

On the other hand, considering the overhang length of the overhang part necessary for engagement, it is desirable that D _mid /B be in the range of 120% or less, so D _mid /B must be in the range of 80% or more and 120% or less. It has also been demonstrated that when a load of a certain level or more is applied, the upper and lower overhanging parts can bear the load as evenly as possible, and it is possible to suppress a decrease in the yield strength of the male joint.

It should be noted that other embodiments may be adopted in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited to the configurations shown here. In this regard, changes can be made without departing from the spirit of the present invention, and can be appropriately determined depending on the application form.

10A: First segment (K segment)
10B: Second segment (B segment)
21: Main girder (steel shell)
22A: First joint plate (steel shell)
22B: Second joint plate (steel shell)
22a: First joint surface 22b: Second joint surface 23: Skin plate (steel shell)
24: Guide groove 30: Male joint 31: First steel bracket 32: First anchor (headed bolt)
33: Male hardware (T type hardware)
34: Base 35: Screwing part 36: Shaft part 37: Overhanging part 40: Female joint 41: Second steel bracket 42: Second anchor (headed bolt)
43: Female hardware 44: Base 45: T-shaped groove 50: Concrete body 60: Segment joint L: Straight line

Claims (4)

A first segment and a second segment, which are concrete segments that are adjacent to each other in the circumferential direction of the tunnel, each have a first joint surface and a second joint surface, and a male joint provided on the first joint surface and a second joint surface. A segment joint in which a female joint provided on two joint surfaces is connected,
The male joint is
a male metal fitting protruding from the first joint surface;
a first anchor attached to the base of the male hardware and formed by a headed bolt;
The female joint is
a female hardware disposed inside the second segment relative to the second joint surface;
a second anchor attached to the base of the female joint and formed by a headed bolt;
The male metal fitting is a T-shaped metal fitting having a T-shape in side view,
The female metal fitting is provided with a T-shaped groove having a T-shape in side view, with which the T-shaped metal fitting engages.
The male joint and the female joint are arranged in a straight line in a state in which the T-shaped metal fitting is engaged with the T-shaped groove,
The second joint surface is provided with a guide groove that extends in the longitudinal direction of the second joint surface and into which the male metal fitting can slide.
The female hardware is disposed within the guide groove so as to be freely engageable with the male hardware,
The T-shaped hardware includes a central shaft portion and an overhanging portion extending above and below the shaft portion at the tip of the shaft portion,
In the T-shaped hardware, the width of the protruding portion in a plan view changes in a tapered shape in the sliding direction of sliding in the guide groove,
The T-shaped groove has a shape in plan view that is complementary to the shape in plan view of the T-shaped metal piece,
In a state in which the T-shaped metal fitting is engaged with the T-shaped groove, both engaging surfaces are in wedge-shaped surface contact,
In the T-shaped hardware, among the widths in plan view of the overhanging part that changes in a tapered shape, an intermediate width: D _mid between the maximum width: D _max and the minimum width: D _min , and the axis of the overhanging part. A segment joint characterized in that the ratio of the overhang length from the section to the length L: D _mid /L is in a range of 100% or more. The segment joint according to claim 1 , characterized in that the D _mid /L is in a range of 150% or more. In the T-shaped hardware, among the widths in plan view of the overhanging part that changes in a tapered shape, _an intermediate width between the maximum width: D _max and the minimum width: D _min , and the width of the shaft part: B. The segment joint according to claim 1 or 2 , wherein the ratio: D _mid /B is in a range of 80% or more and 120% or less. The concrete-based segment is a composite segment having a steel shell and a concrete body inside the steel shell, and the first segment and the second segment each include a first joint plate and a second joint plate, The first joint surface and the second joint surface are joint surfaces provided by the first joint plate and the second joint plate, respectively,
The male joint further includes a first steel bracket fixed to the steel shell of the first segment, and the first steel bracket and the male hardware are connected via the first anchor,
The female joint further includes a second steel bracket fixed to the steel shell of the second segment, and the second steel bracket and the female hardware are connected via the second anchor. Segment joint according to any one of claims 1 to 3, characterized in that:

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