JP2025009931A - Tunnel support connection structure and tunnel support construction method - Google Patents

Abstract

[Problem] To provide a tunnel support connection structure and a tunnel support construction method that enable the connection of a pair of split supports to be performed simply, efficiently, and with high precision.
[Solution] In a tunnel support connecting structure 100, through holes 27A, 27B are opened in the second joint plate 25 of the second divided support 20, a base 35 of a male member 30 is attached to the first joint plate 15 of the first divided support 10 with a tip 34 protruding from the second joint plate, the male member 30 has an accommodating groove 33 and a side opening 36, a pair of claws 40 are arranged in the accommodating groove 33 so as to be able to freely move in and out through the side opening 36, and when the base side ends 42 of the pair of claws 40 are biased by an elastic material 50 to protrude outward through the side opening 36, the engagement recesses 45 provided in the claws 40 engage with the wall surface 36a of the side opening 36 in a face-to-face contact state, the male member 30 is inserted into the through holes 27A, 27B, and the wide surfaces of the first joint plate 15 and the second joint plate 25 abut against each other.
[Selected Figure] Figure 9B

Description

The present invention relates to a tunnel support connection structure and a tunnel support construction method.

For example, when erecting steel shoring in mountain tunnels, a shoring erection device equipped with two erectors on the left and right of a base machine is used to hold a pair of split shoring that are divided into left and right halves and form an arc shape with each erector to form the shoring, and a method is applied in which concrete is sprayed onto the shoring erected along the tunnel wall to fix the shoring to the tunnel wall. In addition to the pair of erectors that hold the split shoring, the base machine is equipped with various devices such as a sprayer that sprays concrete and a basket boom that workers can ride on.

Here, Patent Document 1 discloses a method of erecting tunnel supports, in which an arch-shaped support in which a pair of split supports divided into an arc shape are connected to each other at their upper ends is erected at a tunnel face. In this tunnel support erection method, the upper end of one of the pair of split supports is provided with a concave connector that can engage with a convex connector formed at the upper end of the other, and an erector device having a pair of hands that detachably hold the pair of split supports is placed at the tunnel face, and the pair of hands holding the pair of split supports are moved relative to each other to engage the convex connector with the concave connector, thereby connecting the pair of split supports in an arch shape. The concave connector has a circular insertion hole and a locking hole that is a long hole with a width smaller than the diameter of the insertion hole and is connected to the insertion hole. When erecting the tunnel support, the erector device is controlled to insert the convex connector into the insertion hole of the concave connector, and then the convex connector is moved to the locking hole to connect the convex connector and the concave connector.

JP 2019-2277 A

According to the tunnel support erection method described in Patent Document 1, manual work at the face can be avoided when erecting tunnel supports, improving safety and workability. However, since the erector device is controlled to insert the convex connector into the insertion hole of the concave connector, and then the convex connector is moved to the locking hole to connect the convex connector and the concave connector, it is not easy to control the erector device, and a high level of skill is required to operate the device when erecting tunnel supports.

The present invention aims to provide a tunnel support connection structure and tunnel support construction method that allows the connection of a pair of separate supports to be performed simply, efficiently, and with high precision.

In order to achieve the above object, one aspect of the connection structure of the tunnel support according to the present invention is as follows:
A tunnel support connection structure formed by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support made of steel and having an arc shape,
The second joint plate has a through hole,
A base portion of a male member is attached to the first joint plate and is inserted into the through hole to engage with the second joint plate, and a tip portion of the male member protrudes from the second joint plate,
The male member has an accommodation groove therein, the accommodation groove communicating with a side opening at an opposing position on a side surface of the male member,
The receiving groove has a wedge shape that widens from the tip side to the base side of the male member,
A pair of claws are disposed in the accommodation groove so as to be able to freely enter and exit the accommodation groove through the side opening, and ends of the pair of claws on the base side are biased by an elastic material,
The male member is inserted into the through hole, the wide surfaces of the first joint plate and the second joint plate abut against each other, and the base side ends of the pair of claws engage with or face the wide surface of the second joint plate.

According to this aspect, when a male member protruding from the first joint plate of the first divided support is inserted into the through hole of the second joint plate of the second divided support to connect the two, a pair of claws biased by an elastic material are arranged so as to be able to move freely in and out of the side opening of the male member, and when the male member is inserted into the through hole, the pair of claws protruding from the side opening enter the accommodating groove of the male member, and when the pair of claws pass through the through hole, the pair of claws protrude from the side opening, and the ends of the claws engage with or face the wide surface of the second joint plate, connecting the first divided support and the second divided support.
In other words, by simply inserting the male member protruding from the first joint plate of the first divided support into the through hole of the second joint plate of the second divided support, a connecting structure of tunnel support in which the first divided support and the second divided support are connected can be formed.

Here, "the ends of the pair of claws engage with or face the wide surface of the second joint plate" means that the ends of the claws are in contact with and engaged with the wide surface of the second joint plate, and that there is a clearance between the ends of the claws and the wide surface of the second joint plate, and the two are facing each other. Even in the latter case, since the claws protrude from the wide surface of the second joint plate, the first joint plate and the second joint plate can only move relatively within the range of the clearance, and a connection structure is formed.
For example, a first divided support and a second divided support having the same or approximately the same arc length are applied, the wide surfaces of the first and second joint plates are abutted against each other at the top end of the tunnel, and a male member is inserted into the through hole to engage with the second joint plate, thereby forming a connecting structure for the tunnel support.

In another aspect of the connection structure of the tunnel support according to the present invention,
The pair of claws are provided with engagement recesses on their sides,
The present invention is characterized in that when the base side ends of the pair of claws are biased by an elastic material to protrude outward through the side opening, the engagement recess and the wall surface of the side opening are engaged in a face-to-face contact state.

According to this aspect, when the ends of the base side of the pair of claws are biased by the elastic material and protrude outward through the side opening, the pair of claws engage with the wall surface of the side opening in a surface-to-surface contact state between the engagement recesses provided on the sides of the pair of claws and the wall surface of the side opening, allowing the claws to stably engage with the wall surface of the side opening. For example, if the claw does not have an engagement recess and the side surface of the claw makes point contact with the edge of the side opening, the pressing force from the second joint plate acts on the claw as a concentrated load at the point contact point, and furthermore, a bending moment is generated on the claw starting from the point contact point, making the claw more susceptible to breakage, but these problems can be eliminated.

In another aspect of the connection structure of the tunnel support according to the present invention,
The through hole includes a first through hole located on the face side and a second through hole located on the mouth side,
The male member includes a first male member inserted into the first through hole and a second male member inserted into the second through hole,
The first male member is longer than the second male member.

According to this aspect, the length of the first male member inserted into the first through hole located on the face side is set longer than the second male member inserted into the second through hole located on the tunnel entrance side, of the two through holes provided in the second joint plate.This makes it easier for an operator in the operator's cabin of the heavy equipment attempting to connect the first and second separate supports to distinguish whether the two first and second male members are close or not inside a tunnel with poor visibility (making it easier to grasp the sense of distance), improving the visibility of multiple male members inside the tunnel.
Therefore, for example, a first male member on the face side, which is relatively long, is inserted first into the first through hole located relatively far from the operator, and after the first joint plate and the second joint plate are temporarily connected, a second male member on the wellhead side, which is relatively short, is inserted into the second through hole located relatively close to the operator, thereby improving the workability during connection work (the workability when aligning and inserting multiple male members into corresponding through holes). If the two male members are the same length, when the two male members are simultaneously inserted into the corresponding through holes, it is difficult to see the second male member on the face side, which is located relatively far from the operator, and it is difficult to align the second male member with the first through hole, which reduces the workability during connection work.

Another aspect of the connection structure of the tunnel support according to the present invention is as follows:
A tunnel support connection structure formed by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support made of steel and having an arc shape,
The second joint plate and the first joint plate are provided with a first through hole and a second through hole included in the through hole, and the first through hole is located closer to the face than the second through hole;
A base portion of a first male member included in a male member is attached to the first joint plate, the base portion being inserted into the first through hole and engaged with the second joint plate, and a tip portion of the first male member protrudes from the second joint plate,
A base portion of a second male member included in a male member is attached to the second joint plate, the second male member being inserted into the second through hole and engaged with the first joint plate, and a tip portion of the second male member protrudes from the first joint plate,
The male member has an accommodation groove therein, the accommodation groove communicating with a side opening at an opposing position on a side surface of the male member,
The receiving groove has a wedge shape that widens from the tip side to the base side of the male member,
A pair of claws are disposed in the accommodation groove so as to be able to freely enter and exit the accommodation groove through the side opening, and ends of the pair of claws on the base side are biased by an elastic material,
The male member is inserted into the through hole, the wide surfaces of the first joint plate and the second joint plate abut against each other, and the base side ends of the pair of claws engage with or face the wide surface of the second joint plate.

According to this embodiment, a tunnel support connection structure in which the first and second divided supports are connected can be formed by simply inserting a first male member protruding from the first joint plate of the first divided support into the first through hole of the second joint plate of the second divided support, and inserting a second male member protruding from the second joint plate of the second divided support into the second through hole of the first joint plate of the first divided support.

Furthermore, in this embodiment, since the male members protruding from different joint plates are inserted into corresponding through holes in the different joint plates, construction errors such as inserting male members into the wrong through holes can be prevented when inserting multiple male members into multiple through holes.

In another aspect of the connection structure of the tunnel support according to the present invention,
The pair of claws are provided with engagement recesses on their sides,
The present invention is characterized in that when the base side ends of the pair of claws are biased by an elastic material to protrude outward through the side opening, the engagement recess and the wall surface of the side opening are engaged in a face-to-face contact state.

According to this aspect, when the base-side ends of the pair of claws are biased by the elastic material and protrude outward through the side opening, the pair of claws engage with the engagement recesses on their sides in a state of surface contact with the wall surface of the side opening, allowing the claws to stably engage with the wall surface of the side opening, and there is no problem that the claws are easily damaged by concentrated loads or bending moments.

Another aspect of the connection structure of the tunnel support according to the present invention is as follows:
The first male member is longer than the second male member.

According to this aspect, in addition to the male members protruding from different joint plates being inserted into the corresponding through holes in the different joint plates, the length of the first male member inserted into the first through hole located on the face side is set longer than the second male member inserted into the second through hole located on the mine mouth side, which makes it possible to both prevent construction errors and improve workability during connection construction.

In another aspect of the connection structure of the tunnel support according to the present invention,
the elastic member has a first piece, two second pieces extending from both ends of the first piece in a bent manner, and a third piece extending outward from each of the second pieces in a bent manner, and has a substantially Ω-shaped shape in a side view;
The end portions of the pair of claws on the base side are biased by the pair of third pieces.

According to this aspect, the elastic material has a substantially Ω-shaped shape in side view, with a first piece, two second pieces bending and extending from both ends of the first piece, and a third piece bending and extending outward from each of the second pieces, and the base-side ends of the pair of claws are biased by the pair of third pieces, so that the pair of claws can be biased to protrude from the side opening.

In another aspect of the connection structure of the tunnel support according to the present invention,
The elastic member is a compression coil spring having a central spring and a pair of end springs connected to both ends of the central spring,
the outer diameter of the central spring is greater than the outer diameter of the end springs;
The base end side ends of the pair of claws are biased by the pair of end springs.

According to this aspect, the elastic material is a compression coil spring having a central spring and a pair of end springs connected to both ends thereof, the outer diameter of the central spring is larger than the outer diameter of the end springs, and the base end side ends of the pair of claws are biased by the pair of end springs, so that the pair of claws can be biased to protrude from the side opening, and the biasing force at this time can be increased. Furthermore, even if the male member collides with another member or the like when the male member is transported in the fully assembled state, the compression coil spring housed in the housing groove is highly unlikely to fall out of the housing groove.

In another aspect of the connection structure of the tunnel support according to the present invention,
The pair of claws each have a fitting groove at an end portion on the base side,
The tip of the third piece is fitted into the fitting groove with more than half of the length of the second piece accommodated in the fitting groove.

According to the present embodiment, more than half the length of the second piece of elastic material is accommodated in the fitting groove at the end of the base side of the nail, and the tip of the third piece is further fitted into the fitting groove, making it difficult for the elastic material to come out of the fitting groove of the nail and allowing the biasing force from the elastic material to be stably applied to the nail.
Here, "more than half the length of the second piece is accommodated" means, for example, that half or the entire length of the second piece is accommodated.

In another aspect of the connection structure of the tunnel support according to the present invention,
The pair of claws each have a fitting groove at an end portion on the base side,
The end of the end spring is fitted into the fitting groove.

According to this embodiment, the end of the end spring fits into the fitting groove at the end of the base side of the claw, making it difficult for the elastic material to come out of the fitting groove of the claw, and the biasing force from the elastic material can be stably applied to the claw.

In another aspect of the connection structure of the tunnel support according to the present invention,
A countersunk groove is provided at the bottom of the accommodation groove, and the first piece is accommodated in the countersunk groove.

According to this aspect, the first piece is accommodated in a countersunk groove provided at the bottom of the accommodation groove, which prevents the elastic material from shifting out of position in the accommodation groove, and the elastic material receives a reaction force from the wall of the countersunk groove, allowing a stable biasing force to be applied to the claw.

In another aspect of the connection structure of the tunnel support according to the present invention,
The housing groove has a bottom portion provided with a countersunk groove, and the central spring is housed in the countersunk groove.

According to this aspect, the central spring is accommodated in a countersunk groove provided at the bottom of the accommodation groove, which prevents the elastic material from shifting out of position in the accommodation groove, and the elastic material receives a reaction force from the wall of the countersunk groove, allowing a stable biasing force to be applied to the claw.

In another aspect of the connection structure of the tunnel support according to the present invention,
The tip shape of the male member is any one of a truncated cone, a truncated pyramid, a cone, and a pyramid.

According to this embodiment, the tip shape of the male member is one of a truncated cone, a truncated pyramid, a cone, and a pyramid, which makes it easier to insert the tip of the male member into the through hole.

In addition, one aspect of the tunnel support construction method according to the present invention is to
A tunnel support construction method for forming a tunnel support connection structure by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support, each of which is made of steel and has an arc-shaped configuration,
A preparation step and a connection structure forming step are included,
In the preparation step,
The second joint plate is provided with a first through hole located on the face side and a second through hole located on the mouth side,
a first male member and a second male member are prepared, the first male member and the second male member being inserted into the first through hole and the second through hole, respectively, and engaged with the second joint plate, the male member has an accommodating groove therein, the accommodating groove communicates with side openings at opposing positions on a side surface of the male member, the accommodating groove is wedge-shaped and widens from the tip side to the base side of the male member, a pair of claws are disposed in the accommodating groove so as to be able to freely enter and exit the accommodating groove via the side opening, base side ends of the pair of claws are biased by an elastic material, and the length of the first male member is set longer than that of the second male member,
The first male member and the second male member are respectively attached to the first joint plate;
The connecting structure forming step is characterized in that the first male member and the second male member are inserted into the first through hole and the second through hole, respectively.

According to this aspect, by simply inserting two male members protruding from the first joint plate of the first divided support into two through holes in the second joint plate of the second divided support, a pair of claws can be protruded outward through the side openings to engage with or face the wide surface of the second joint plate, making it easy to construct a tunnel support in which the first divided support and the second divided support are connected.

Here, when connecting the first and second separate shoring, a tunnel shoring erection device equipped with a self-propelled base machine and two sets of two booms is used, and the first and second separate shoring are grasped with each set of booms, and with the second separate shoring (its second joint plate) erected and fixed, the first separate shoring (its two male members) is moved, and the two male members protruding from the first joint plate are inserted into the two through holes of the second joint plate to connect the two.
With this construction method, it is only necessary to move one set of booms of the tunnel support erection device and insert multiple male members into multiple through holes, making it possible to safely and efficiently construct the tunnel support by connecting the first and second separate supports.

Another aspect of the tunnel support construction method according to the present invention is as follows:
A tunnel support construction method for forming a tunnel support connection structure by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support, each of which is made of steel and has an arc-shaped configuration,
A preparation step and a connection structure forming step are included,
In the preparation step,
A first through hole is opened in the second joint plate, a second through hole is opened in the first joint plate, and the first through hole is positioned closer to the face side than the second through hole;
a first male member included in a male member which is inserted into the first through hole and engaged with the second joint plate; and a second male member included in a male member which is inserted into the second through hole and engaged with the first joint plate, the male member has an accommodating groove therein, the accommodating groove communicates with side openings at opposing positions on a side surface of the male member, the accommodating groove has a wedge shape which widens from the tip side toward the base side of the male member, a pair of claws are disposed in the accommodating groove so as to be able to freely enter and exit the accommodating groove via the side opening, and base side ends of the pair of claws are biased by an elastic material;
attaching the first male member and the second male member to the first joint plate and the second joint plate, respectively;
The connecting structure forming step is characterized in that the first male member and the second male member are simultaneously inserted through the first through hole and the second through hole, respectively.

According to this aspect, tunnel support in which the first and second divided supports are connected can be easily constructed, the claws can be stably engaged with the wall surface of the side opening, and further, since the male members protruding from different joint plates are inserted into corresponding through holes in different joint plates, construction errors such as inserting male members into the wrong through holes can be prevented when inserting multiple male members into multiple through holes.

In another aspect of the tunnel support construction method according to the present invention,
In the preparation step, a length of the first male member is set to be longer than that of the second male member,
The connecting structure forming step is characterized in that after the first male member is inserted into the first through hole, the second male member is inserted into the second through hole.

According to this aspect, the first male member on the face side, which is relatively long, is inserted first into the first through hole located relatively far from the heavy equipment operator, and then the second male member on the mouth side, which is relatively short, is inserted into the second through hole located relatively close to the heavy equipment operator. This makes it easier to see the first male member located far from the operator and to grasp the sense of distance, and improves the insertability of the first male member into the first through hole. Furthermore, by inserting the relatively long first male member into the first through hole first, and then inserting the relatively short second male member into the second through hole, the time required to align and insert the second male member into the second through hole can be shortened.

The tunnel support connection structure and tunnel support construction method of the present invention allow a pair of split supports to be connected easily, efficiently, and with high precision.

FIG. 1 is an oblique view of an example of a male member that constitutes the connecting structure of a tunnel support according to an embodiment, viewed from the rear of its base. FIG. 1 is an oblique view of an example of a male member that constitutes the connecting structure of a tunnel support according to an embodiment, viewed from the tip side of its main body. FIG. 11 is a vertical cross-sectional view showing a state in which a pair of claws are inserted into an accommodating groove in an example of a male member. FIG. 11 is a vertical cross-sectional view of an example of a male member showing a pair of claws protruding from a side opening. FIG. 11 is a process diagram of an example of a method for assembling an example of a male member. 4A , which is a process diagram of an example of a method for assembling an example of a male member. 4B , a process diagram of an example of a method for assembling an example of a male member is shown. FIG. 11 is a vertical cross-sectional view showing a state in which a pair of claws are inserted into the receiving groove in another example of a male member. FIG. 11 is a vertical cross-sectional view showing another example of a male member with a pair of claws protruding from a side opening. This is an oblique view of two male members protruding from the wide surface of the first joint plate of the first divided support, viewed from the tip side of the male members. This is an oblique view of two male members protruding from the wide surface of the first joint plate of the first divided support, viewed from the base side of the male members. An oblique view of the second divided support from the front wide surface side of the second joint plate. FIG. 2 is a process diagram illustrating an example of a construction method for tunnel support according to the first embodiment. Following Figure 9A, this is a process diagram explaining an example of a construction method for tunnel support in the first embodiment, and also shows an example of a connecting structure for the tunnel support in the first embodiment. A process diagram illustrating an example of a construction method for tunnel support in the second embodiment. Following Figure 10A, this is a process diagram explaining an example of a construction method for tunnel support in the second embodiment, and also shows an example of a connecting structure of the tunnel support in the second embodiment. FIG. 11 is a process diagram illustrating an example of a construction method for tunnel support in accordance with the third embodiment. Following Figure 11A, this is a process diagram explaining an example of a construction method for tunnel support in the third embodiment, and also shows an example of a connecting structure for the tunnel support in the third embodiment. A process diagram illustrating an example of a construction method for tunnel support in the fourth embodiment. Following Figure 12A, this is a process diagram explaining an example of a construction method for tunnel support relating to the fourth embodiment, and also shows an example of a connecting structure for the tunnel support relating to the fourth embodiment.

Below, an example of a tunnel support connection structure and a tunnel support construction method according to each embodiment will be described with reference to the attached drawings. Note that in this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[Male member forming the connection structure of the tunnel support according to the embodiment]
First, with reference to Figures 1 to 8, we will explain an example of a male member that forms the connecting structure of the tunnel support in each embodiment, an example of a first divided support having a first joint plate to which the male member is attached, and an example of a second divided support having a second joint plate through which the male member is inserted.
Here, Fig. 1 and Fig. 2 are perspective views of an example of a male member constituting a connection structure of a tunnel support according to an embodiment, as viewed from the rear of the base and the tip of the main body. Fig. 3A and Fig. 3B are vertical cross-sectional views of an example of a male member, showing a state in which a pair of claws enter the accommodation groove and a state in which a pair of claws protrude from a side opening, and Fig. 4A to Fig. 4C are process diagrams of an example of an assembly method of an example of a male member, in order. Fig. 5A and Fig. 5B are vertical cross-sectional views of another example of a male member, showing a state in which a pair of claws enter the accommodation groove and a state in which a pair of claws protrude from a side opening. Fig. 6 and Fig. 7 are perspective views of a state in which two male members protrude from the wide surface of the first joint plate of the first divided support, as viewed from the tip side and base side of the male member, and Fig. 8 is a perspective view of the second divided support, as viewed from the wide surface side of the second joint plate.

As shown in Figures 1 to 4, the male member 30 has a cylindrical main body 31 with an internal storage groove 33, and the storage groove 33 communicates with a side opening 36 located at an opposing position on the side of the main body 31. The tip 34 of the main body 31 has a truncated cone shape, and the rear end of the main body 31 is provided with a base 35, which is a cylindrical flange with a larger diameter than the main body 31. The male member 30 is a pin member made as a whole from steel, aluminum, or the like.

Here, in addition to the illustrated example, the tip may be conical, and further, if the main body is prismatic, the tip may be truncated pyramid or pyramidal.

The tip 34 of the main body 31 has a truncated cone shape, making it easier for the main body 31 to be inserted into the through hole of the joint plate.

The storage groove 33 is wedge-shaped and widens from the tip side of the main body 31 toward the base side, and a pair of claws 40 are arranged inside the storage groove 33 so that they can freely move in and out of the storage groove 33 through a pair of side openings 36.

The claw 40 in the illustrated example has a generally trapezoidal shape whose width increases in plan view from the tip end 41 toward the base end 42, and a fitting groove 47 is provided on the inside of the base end 42.

As shown in Figures 3A and 3B, a countersunk groove 33a is provided on the base side of the housing groove 33 of the main body 31, and the first piece 51 of the elastic material 50 formed by a leaf spring is housed in the countersunk groove 33a.

The elastic material 50 has a first piece 51, two second pieces 52 that bend and extend from both ends of the first piece 51, and two third pieces 53 that bend and extend outward from each of the second pieces 52, and has a roughly Ω-shaped shape when viewed from the side.

With more than half of the length of the second piece 52 of the elastic material 50 housed in the fitting groove 47, the tip of the third piece 53 fits into the corner of the end of the fitting groove 47.

In this way, the first piece 51 of the elastic material 50 is accommodated in the countersunk groove 33a, and more than half the length of the second piece 52 of the elastic material 50 is accommodated in the fitting groove 47, with the tip of the third piece 53 further fitted in. This prevents the elastic material 50 from shifting out of position in the accommodation groove 33, makes it difficult for the elastic material 50 to come out of the fitting groove 47, and allows the biasing force from the elastic material 50 to be stably applied to the claw 40 while receiving a reaction force from the countersunk groove 33a.

As shown in FIG. 3A, the ends 42 on the base side of the pair of claws 40 are biased in the X1 direction, projecting laterally from the elastic material 50, and when the main body 31 of the male member 30 is inserted into the through hole of the joint plate, the claws 40 receive a pushing force P from the wall surface of the through hole, causing the claws 40 to enter the inside of the accommodation groove 33.

On the other hand, when the claw 40 passes through the through hole of the joint plate, as shown in FIG. 3B, the claw 40 is released from the pushing force from the wall surface of the through hole, and is biased in the X1 direction by the elastic material 50, causing it to protrude laterally from the side opening 36 in the X2 direction.

As shown in Figures 3A and 3B, each of the pair of claws 40 has an engagement recess 45 on its side, and when the claw 40 protrudes outward through the side opening 36 as shown in Figure 3B, the engagement recess 45 and the wall surface 36a of the side opening 36 engage in a surface contact state.

In this way, when the claw 40 is biased by the elastic material 50 and protrudes outward through the side opening 36 of the main body 31, the engagement recess 45 on the side of the claw 40 engages with the wall surface 36a of the side opening 36 in a surface contact state, allowing the claw 40 to engage with the wall surface 36a of the side opening 36 in a stable state.

For example, if the claw does not have an engagement recess and the side of the claw makes point contact with the edge of the side opening, the pushing force from the joint plate to the claw acts as a concentrated load on the point contact point, generating a bending moment on the claw starting from the point contact point, making the claw more susceptible to breakage; however, due to the engagement structure of the claw 40 and side opening 36 in the illustrated example, such a problem does not occur.

To outline an example of how to assemble the male member 30, first, as shown in FIG. 4A, one claw 40 is inserted in the Y1 direction into the receiving groove 33 through one of the side openings 36.

Next, as shown in FIG. 4B, the elastic material 50 is accommodated in the accommodation groove 33 in the Y2 direction through the other side opening 36, and the first piece 51 of the elastic material 50 is placed in the countersunk groove 33a. At this time, the second piece 52 and the third piece 53 of one of the elastic material 50 are accommodated in the fitting groove 47, and the third piece 53 is engaged with a part of the fitting groove 47.

Next, as shown in FIG. 4C, the other claw 40 is inserted in the Y3 direction into the accommodation groove 33 through the other side opening 36, the other second piece 52 and third piece 53 of the elastic material 50 are accommodated in the fitting groove 47, and the third piece 53 is engaged with a part of the fitting groove 47, thereby assembling the male member 30.

In this way, the male member 30 can be easily assembled, and once assembled, the male member 30 has a structure that makes it difficult for the parts to come apart.

Here, instead of the male member 30 having the elastic material 50 shown in Figures 3 and 4, a male member 30D having an elastic material 50A made of a compression coil spring shown in Figures 5A and 5B may be applied.

The elastic material 50A is a compression coil spring having a central spring 55 and a pair of end springs 56 connected to both ends of the central spring 55, and the outer diameter t1 of the central spring 55 is larger than the outer diameter t2 of the end springs 56.

A central spring 55 with a relatively large outer diameter t1 is accommodated in the countersunk groove 33a on the base side of the accommodation groove 33 of the main body 31, and the end of the end spring 56 fits into the fitting groove 47.

In this way, the central spring 55 of the elastic material 50A is accommodated in the countersunk groove 33a, and the end of the end spring 56 of the elastic material 50A is fitted into the fitting groove 47, preventing the elastic material 50A from shifting position in the accommodation groove 33, making it difficult for the elastic material 50A to come off from the fitting groove 47, and allowing the biasing force from the elastic material 50A to be stably applied to the claw 40 while receiving a reaction force from the countersunk groove 33a.

In particular, by accommodating the relatively large diameter central spring 55 in the countersunk groove 33a, the elastic material 50A made of a compression coil spring can be held in a stable accommodation position in the accommodation groove 33, making it easier to apply a reaction force to the countersunk groove 33a. In addition, because the end of the end spring 56 with an outer diameter t2 presses the mating groove 47 in a planar manner, the claw 40 can be pushed out in a more stable state than, for example, a form in which it is pressed in at a point.

Furthermore, as shown in FIG. 5B, even if the male member 30D collides with another member when it is transported in the fully assembled state, the compression coil spring 50A housed in the housing groove 33 is unlikely to fall out of the housing groove 33.

As shown in FIG. 5A, the ends 42 on the base side of the pair of claws 40 are biased in the X1 direction, projecting laterally from the elastic material 50A, and when the main body 31 of the male member 30D is inserted into the through hole of the joint plate, the claws 40 receive a pushing force P from the wall surface of the through hole, causing the claws 40 to enter the inside of the accommodation groove 33.

On the other hand, when the claw 40 passes through the through hole of the joint plate, as shown in FIG. 5B, the claw 40 is released from the pushing force from the wall surface of the through hole, and is biased in the X1 direction by the elastic material 50A, causing it to protrude laterally from the side opening 36 in the X2 direction.

As shown in Figures 5A and 5B, each of the pair of claws 40 has an engagement recess 45 on its side, and when the claw 40 protrudes outward through the side opening 36 as shown in Figure 5B, the engagement recess 45 and the wall surface 36a of the side opening 36 engage in a surface contact state.

In this way, when the claw 40 is biased by the elastic material 50A and protrudes outward through the side opening 36 of the main body 31, the engagement recess 45 on the side of the claw 40 engages with the wall surface 36a of the side opening 36 in a surface contact state, allowing the claw 40 to engage with the wall surface 36a of the side opening 36 in a stable state.

As shown in Figures 6 and 7, a first joint plate 15 made of steel is welded to one end 11 of the first divided support 10, which is an arc-shaped structure made of H-shaped steel. Two through holes 17A and 17B are opened in the first joint plate 15, spaced apart from each other, for example, on the left and right. Here, the through hole 17B on the tunnel mouth side and the through hole 17A on the tunnel face side are both through holes for mounting the male member 30. In the following explanation, the male member 30 having the elastic material 50 or a modified version thereof is described as being applied, but instead of the male member 30, a male member 30D having the elastic material 50A may be applied.

The diameters of the first mounting through hole 17A and the second mounting through hole 17B are set to be equal to or slightly larger than the diameter of the main body 31 of the male member 3 and smaller than the diameter of the base 35 of the male member 30.

The base 35 of the male member 30 engages with the wide surface on the rear side of the first joint plate 15. One piece of a steel fixed angle 60 that bends from the web constituting the first divided support 10 to the rear side of the first joint plate 15 presses down on the rear end surface of the base 35, while the other piece of the fixed angle 60 is fixed to the web via a bolt 61, thereby fixing the male member 30 so that it cannot move relative to the first joint plate 15. In addition to the fixed angle 60, the rear side of the first joint plate 15 and the base 35 may be directly joined by welding.

As shown in FIG. 6, when the male member 30 protrudes from the wide surface 16 at the front of the first joint plate 15, a gap G of a predetermined length is provided between the claw 40 protruding laterally and the wide surface 16. The second joint plate 25 is disposed in this gap G, as described below.

On the other hand, as shown in FIG. 8, a second steel joint plate 25 is welded to one end 21 of the arc-shaped second divided support 20 formed from H-shaped steel, and a first through hole 27A on the face side and a second through hole 27B on the mouth side are opened on the wide surface 26 of the second joint plate 25, spaced apart from each other, for example, to the left and right.

The first and second divided supports 10 and 20 are both formed from H-shaped steel beams with the same cross-sectional dimensions and the same (or nearly the same) arc lengths, and the first and second joint plates 15 and 25 are also formed from steel plates of the same dimensions. Furthermore, the positions of the first through hole 27A and the second through hole 27B of the second joint plate 25 correspond to the positions of the first male member 30A and the second male member 30B protruding from the first joint plate 15 when the wide surface 16 of the first joint plate 15 and the wide surface 26 of the second joint plate 25 abut against each other.

When connecting the first and second separate supports 10 and 20 to form the connected structure of the tunnel supports, the first and second separate supports 10 and 20 are each grasped by the chucks of two branch booms of the support erection device (not shown).

The shoring erection device (not shown) is, for example, a device equipped with a self-propelled base machine and two sets of booms, and each set of booms grasps the first divided shoring 10 and the second divided shoring 20. With the second joint plate 25 of the second divided shoring 20 erected and fixed, the first joint plate 15 of the first divided shoring 10 is moved, and the two first male members 30A and second male members 30B protruding from the first joint plate 15 are inserted into the two first through holes 27A and second through holes 27B of the second joint plate 25, respectively, to connect the two.

At this time, the operator in the operator cabin of the base machine visually checks the first through hole 27A, which is located on the face side and relatively far from the operator, and the second through hole 27B, which is located on the mine mouth side and relatively close to the operator, and aligns the first male member 30A and the second male member 30B with respect to each of them and operates the machine to insert them.

Below, we will explain the tunnel support construction methods according to several embodiments and the tunnel support connection structures formed by each construction method.

[Construction method of tunnel support according to the first embodiment and connection structure of tunnel support]
Next, an example of a tunnel support construction method and a tunnel support connection structure according to the first embodiment will be described with reference to Fig. 9A and Fig. 9B. Here, Fig. 9A is a process diagram for explaining an example of a tunnel support construction method according to the first embodiment, and Fig. 9B is a process diagram for explaining an example of a tunnel support construction method according to the first embodiment following Fig. 9A, and also shows an example of a tunnel support connection structure according to the first embodiment.

Here, in each figure, an operator in the operator cabin of the base machine (not shown) visually checks the first joint plate 15 of the first separate support 10 and the second joint plate 25 of the second separate support 20 in the Z1 direction from the mine mouth side, and this is also the case in the following Figures 10 to 12.

As shown in FIG. 9A, a first joint plate 15 and a second joint plate 25 are fixed to one end of each of the first and second divided supports 10 and 20, which are made of steel and have an arc shape.

The second joint plate 25 has a first through hole 27A located on the face side and a second through hole 27B located on the mouth side.

Meanwhile, the first male member 30A is attached to the first mounting through hole 17A located on the face side of the first joint plate 15, and the second male member 30B is attached to the second mounting through hole 17B located on the mine mouth side. Here, the first male member 30A and the second male member 30B are members of the same shape and dimensions (preparation process above).

Next, as shown in FIG. 9A, with the second joint plate 25 of the second divided support 20 erected and fixed, the first joint plate 15 of the first divided support 10 is moved, and the two first male members 30A and the second male members 30B protruding from the first joint plate 15 are aligned with the two first through holes 27A and the two second through holes 27B of the second joint plate 25, respectively, and inserted in the Z2 direction.

During this insertion process, the first male member 30A and the second male member 30B are both in a position in which the pair of claws 40 are pressed into the accommodation groove 33 as shown in FIG. 3A, and when the pair of claws 40 pass through the first through hole 27A and the second through hole 27B, the pair of claws 40 protrude laterally from the side opening 36 as shown in FIG. 3B.

When the pair of claws 40 of each male member 30A, 30B protrudes laterally from the side opening 36, the wide surfaces 16, 26 of the first joint plate 15 and the second joint plate 25 abut against each other, as shown in FIG. 9B, and the base side ends 42 of each pair of claws 40 face the wide surface 26 of the second joint plate 25 with a clearance C, thereby forming a connecting structure 100 for the tunnel support (above, the connecting structure forming process).

According to the tunnel support construction method shown in the figure, the tunnel support connection structure 100 in which the first divided support 10 and the second divided support 20 are connected can be constructed simply, efficiently, and with high precision by simply inserting the first male member 30A and the second male member 30B protruding from the first joint plate 15 of the first divided support 10 into the first through hole 27A and the second through hole 27B of the second joint plate 25 of the second divided support 20, respectively.

In addition, the tips 34 of the first male member 30A and the second male member 30B are shaped like truncated cones, making it easier to insert the main body 31 into the through hole of the joint plate, which also improves workability.

Furthermore, when the pair of claws 40 are biased by the elastic material 50 and protrude outward through the side opening 36 of the main body 31, the formed tunnel support connection structure 100 can stably engage with the wall surface 36a of the side opening 36 because the engagement recesses 45 on the sides of the claws 40 engage with the wall surface 36a of the side opening 36 in a face-to-face contact state. This prevents concentrated loads from acting on the claws 40 and bending moments from occurring even when the pair of claws 40 receive a pushing force from the second joint plate 25, suppressing damage to the claws 40, and thus forming a high-strength, high-durability connection structure 100.

[Construction method of tunnel support according to the second embodiment and connection structure of tunnel support]
Next, an example of a tunnel support construction method and a tunnel support connection structure according to the second embodiment will be described with reference to Figures 10A and 10B. Here, Figure 10A is a process diagram for explaining an example of a tunnel support construction method according to the second embodiment, and Figure 10B is a process diagram for explaining an example of a tunnel support construction method according to the second embodiment following Figure 10A, and also shows an example of a tunnel support connection structure according to the second embodiment.

The construction method and connection structure 100A shown in the illustration differs from the construction method and connection structure 100 shown in Figures 9A and 9B in that the length of the first male member 30C on the face side is set longer than the length of the second male member 30B on the mine mouth side.

As shown in FIG. 10A, the tip 34A of the first male member 30C is longer than that of the second male member 30B, and as a result, the protruding length from the wide surface 16 of the first joint plate 15 is relatively longer. That is, in the preparation process, the second male member 30B is attached to the first joint plate 15 via the second attachment through hole 17B located on the mine mouth side, and the first male member 30C, which is longer than the second male member 30B, is attached to the first joint plate 15 via the first attachment through hole 17A located on the face side.

In the connection structure forming process, the first male member 30C, which has a relatively long length, is first inserted in the Z3 direction into the first through hole 27A of the second joint plate 25, and then the second male member 30B is inserted into the second through hole 27B, thereby forming the connection structure 100A shown in FIG. 10B.

According to the tunnel support construction method shown in the figure, the first male member 30C on the face side, which is relatively long, is first inserted into the first through hole 27A located relatively far from the heavy equipment operator, and then the second male member 30B on the entrance side, which is relatively short, is inserted into the second through hole 27B located relatively close to the heavy equipment operator. This makes it easier to see the first male member 30C located far from the operator and to grasp the sense of distance, and improves the insertability of the first male member 30C into the first through hole 27A.

Furthermore, by first inserting the relatively long first male member 30C into the first through hole 27A and then inserting the relatively short second male member 30B into the second through hole 27B, the time required to align and insert the second male member 30B into the second through hole 27B can be reduced.

[Tunnel support construction method and tunnel support connection structure according to the third embodiment]
Next, an example of a tunnel support construction method and a tunnel support connection structure according to the third embodiment will be described with reference to Fig. 11A and Fig. 11B. Here, Fig. 11A is a process diagram for explaining an example of a tunnel support construction method according to the third embodiment, and Fig. 11B is a process diagram for explaining an example of a tunnel support construction method according to the third embodiment following Fig. 11A, and also shows an example of a tunnel support connection structure according to the third embodiment.

The construction method and connection structure 100B of the illustrated example differs from the construction method and connection structure 100 shown in Figures 9A and 9B in that a first male member 30A is attached to the first mounting through hole 17A on the face side of the first joint plate 15, and a second male member 30B is attached to the mounting through hole 27 on the wellhead side of the second joint plate 25, and each is inserted into the first through hole 27A of the second joint plate 25 and the second through hole 17C of the first joint plate 15, i.e., one male member 30 is attached to each of the two joint plates 15, 25 and inserted into the through holes 27A, 17C of the other joint plate 25, 15.

As shown in FIG. 11A, in the preparation process, the first male member 30A is attached to the first mounting through hole 17A located on the face side of the first joint plate 15, and the second male member 30B is attached to the mounting through hole 27C located on the mouth side of the second joint plate 25.

In the connection structure forming process, the first male member 30A and the second male member 30B are simultaneously inserted in the Z4 direction through the first through hole 27A of the second joint plate 25 and the second through hole 17C of the first joint plate 15, respectively, to form the connection structure 100B shown in FIG. 11B.

According to the tunnel support construction method shown in the figure, the male members 30 protruding from different joint plates 15, 25 are inserted into the corresponding through holes 27A, 17C in the different joint plates 25, 15, so construction errors such as inserting male members into the wrong through holes can be prevented when inserting multiple male members into multiple through holes.

[Tunnel support construction method and tunnel support connection structure according to the fourth embodiment]
Next, an example of a tunnel support construction method and a tunnel support connection structure according to the fourth embodiment will be described with reference to Fig. 12A and Fig. 12B. Fig. 12A is a process diagram for explaining an example of a tunnel support construction method according to the fourth embodiment, and Fig. 12B is a process diagram for explaining an example of a tunnel support construction method according to the fourth embodiment following Fig. 12A, and also shows an example of a tunnel support connection structure according to the fourth embodiment.

The illustrated construction method and connection structure 100C differs from the construction method and connection structure 100B shown in Figures 11A and 11B in that the length of the first male member 30C attached to the first joint plate 15 is set longer than the length of the second male member 30B attached to the second joint plate 25.

As shown in FIG. 12A, in the preparation process, the first male member 30C is attached to the first mounting through hole 17A located on the face side of the first joint plate 15, and the second male member 30B is attached to the mounting through hole 27C located on the mouth side of the second joint plate 25.

In the connection structure forming process, the first male member 30C, which has a relatively long length, is first inserted in the Z5 direction into the first through hole 27A of the second joint plate 25, and then the second male member 30B is inserted into the second through hole 17C, forming the connection structure 100C shown in FIG. 12B.

The tunnel support construction method shown in the figure makes the first male member 30C, which is located far from the operator, easier to see, making it easier to grasp the sense of distance, and improves the insertion ability of the first male member 30C into the first through hole 27A.

In addition, by first inserting the relatively long first male member 30C into the first through hole 27A and then inserting the relatively short second male member 30B into the second through hole 17C, the time required to align and insert the second male member 30B into the second through hole 17C can be reduced.

Furthermore, since the male members 30 protruding from the different joint plates 15, 25 are inserted into the corresponding through holes 27A, 17C in the different joint plates 25, 15, construction errors such as inserting male members into the wrong through holes can be prevented when inserting multiple male members into multiple through holes.

Note that other embodiments may be possible in which other components are combined with the configurations described 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 determined appropriately according to the application form.

10: First divided support 11: One end 12: Web 13: Flange 15: First joint plate (joint plate)
16: Wide surface 17A: First mounting through hole (through hole)
17B: Second mounting through hole (through hole)
17C: Second through hole (through hole)
20: Second divided support 21: One end 22: Web 23: Flange 25: Second joint plate (joint plate)
26: wide surface 27A: first through hole (through hole)
27B: Second through hole (through hole)
27C: Mounting through hole 30: Male member 30A, 30C: First male member (male member)
30B: Second male member (male member)
30D: Male member 31: Main body 33: Housing groove 33a: Countersunk groove 34, 34A: Tip 35: Base 36: Side opening 36a: Wall surface 40: Claw 41: Tip end 42: Base end 45: Engagement recess 47: Fitting groove 50: Elastic material 50A: Elastic material (compression coil spring)
51: First piece 52: Second piece 53: Third piece 55: Central spring 56: End spring 60: Fixed angle 61: Bolt 100, 100A, 100B, 100C: Tunnel support connection structure (connection structure)
G: Gap C: Clearance

Claims (16)

A tunnel support connection structure formed by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support made of steel and having an arc shape,
The second joint plate has a through hole,
A base portion of a male member is attached to the first joint plate and is inserted into the through hole to engage with the second joint plate, and a tip portion of the male member protrudes from the second joint plate,
The male member has an accommodation groove therein, the accommodation groove communicating with a side opening at an opposing position on a side surface of the male member,
The receiving groove has a wedge shape that widens from the tip side to the base side of the male member,
A pair of claws are disposed in the accommodation groove so as to be able to freely enter and exit the accommodation groove through the side opening, and ends of the pair of claws on the base side are biased by an elastic material,
A tunnel support connection structure, characterized in that the male member is inserted into the through hole, the wide surfaces of the first joint plate and the second joint plate abut against each other, and the base side ends of the pair of claws engage with or face the wide surface of the second joint plate. The pair of claws are provided with engagement recesses on their sides,
A tunnel support connection structure as described in claim 1, characterized in that when the base side ends of the pair of claws are biased by an elastic material to protrude outward through the side opening, the engagement recess and the wall surface of the side opening are engaged in a face-to-face contact state. The through hole includes a first through hole located on the face side and a second through hole located on the mouth side,
The male member includes a first male member inserted into the first through hole and a second male member inserted into the second through hole,
2. The tunnel support connection structure according to claim 1, wherein the length of the first male member is set longer than that of the second male member. A tunnel support connection structure formed by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support made of steel and having an arc shape,
The second joint plate and the first joint plate are provided with a first through hole and a second through hole included in the through hole, and the first through hole is located closer to the face than the second through hole;
A base portion of a first male member included in a male member is attached to the first joint plate, the base portion being inserted into the first through hole and engaged with the second joint plate, and a tip portion of the first male member protrudes from the second joint plate,
A base portion of a second male member included in a male member is attached to the second joint plate, the second male member being inserted into the second through hole and engaged with the first joint plate, and a tip portion of the second male member protrudes from the first joint plate,
The male member has an accommodation groove therein, the accommodation groove communicating with a side opening at an opposing position on a side surface of the male member,
The receiving groove has a wedge shape that widens from the tip side to the base side of the male member,
A pair of claws are disposed in the accommodation groove so as to be able to freely enter and exit the accommodation groove through the side opening, and ends of the pair of claws on the base side are biased by an elastic material,
A tunnel support connection structure, characterized in that the male member is inserted into the through hole, the wide surfaces of the first joint plate and the second joint plate abut against each other, and the base side ends of the pair of claws engage with or face the wide surface of the second joint plate. The pair of claws are provided with engagement recesses on their sides,
The tunnel support connection structure described in claim 4, characterized in that when the base side ends of the pair of claws are biased by an elastic material to protrude outward through the side opening, the engagement recess and the wall surface of the side opening are engaged in a face-to-face contact state. The tunnel support connection structure according to claim 4, characterized in that the length of the first male member is set longer than that of the second male member. the elastic member has a first piece, two second pieces extending from both ends of the first piece in a bent manner, and a third piece extending outward from each of the second pieces in a bent manner, and has a substantially Ω-shaped shape in a side view;
5. A tunnel support connection structure as described in claim 1 or 4, characterized in that the base side ends of the pair of claws are biased by a pair of the third pieces. The elastic member is a compression coil spring having a central spring and a pair of end springs connected to both ends of the central spring,
the outer diameter of the central spring is greater than the outer diameter of the end springs;
5. A tunnel support connection structure as described in claim 1 or 4, characterized in that the base end side ends of the pair of claws are biased by the pair of end springs. The pair of claws each have a fitting groove at an end portion on the base side,
The tunnel support connection structure according to claim 7, characterized in that the tip of the third piece is fitted into the fitting groove with more than half of the length of the second piece accommodated in the fitting groove. The pair of claws each have a fitting groove at an end portion on the base side,
The tunnel support connection structure according to claim 8, characterized in that an end of the end spring is fitted into the fitting groove. The tunnel support connection structure according to claim 7, characterized in that a countersunk groove is provided at the bottom of the accommodation groove, and the first piece is accommodated in the countersunk groove. The tunnel support connection structure according to claim 8, characterized in that a countersunk groove is provided at the bottom of the accommodation groove, and the central spring is accommodated in the countersunk groove. The tunnel support connection structure according to claim 1 or 4, characterized in that the tip shape of the male member is one of a truncated cone, a truncated pyramid, a cone, and a pyramid. A tunnel support construction method for forming a tunnel support connection structure by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support, each of which is made of steel and has an arc shape, comprising:
A preparation step and a connection structure forming step are included,
In the preparation step,
The second joint plate is provided with a first through hole located on the face side and a second through hole located on the mouth side,
a first male member and a second male member are prepared, the first male member and the second male member being inserted into the first through hole and the second through hole, respectively, and engaged with the second joint plate, the male member has an accommodating groove therein, the accommodating groove communicates with side openings at opposing positions on a side surface of the male member, the accommodating groove is wedge-shaped and widens from the tip side to the base side of the male member, a pair of claws are disposed in the accommodating groove so as to be able to freely enter and exit the accommodating groove via the side opening, base side ends of the pair of claws are biased by an elastic material, and the length of the first male member is set longer than that of the second male member,
The first male member and the second male member are respectively attached to the first joint plate;
A tunnel support construction method, characterized in that in the connecting structure formation process, the first male member and the second male member are inserted into the first through hole and the second through hole, respectively. A tunnel support construction method for forming a tunnel support connection structure by connecting a first joint plate and a second joint plate at one end of a first divided support and a second divided support, each of which is made of steel and has an arc-shaped configuration,
A preparation step and a connection structure forming step are included,
In the preparation step,
A first through hole is opened in the second joint plate, a second through hole is opened in the first joint plate, and the first through hole is positioned closer to the face side than the second through hole;
a first male member included in a male member which is inserted into the first through hole and engaged with the second joint plate; and a second male member included in a male member which is inserted into the second through hole and engaged with the first joint plate, the male member has an accommodating groove therein, the accommodating groove communicates with side openings at opposing positions on a side surface of the male member, the accommodating groove has a wedge shape which widens from the tip side toward the base side of the male member, a pair of claws are disposed in the accommodating groove so as to be able to freely enter and exit the accommodating groove via the side opening, and base side ends of the pair of claws are biased by an elastic material;
attaching the first male member and the second male member to the first joint plate and the second joint plate, respectively;
A tunnel support construction method, characterized in that, in the connecting structure formation process, the first male member and the second male member are simultaneously inserted into the first through hole and the second through hole, respectively. In the preparation step, a length of the first male member is set to be longer than that of the second male member,
16. The tunnel support construction method of claim 14 or 15, characterized in that in the connecting structure formation process, the first male member is inserted into the first through hole, and then the second male member is inserted into the second through hole.

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