JP7517010B2 - Connection structure, connection method, and segment - Google Patents

Description

This disclosure relates to a connection structure, a connection method, and a segment, and in particular to a technology suitable for connecting a main tunnel and an adit.

Various methods have been proposed for connecting the main tunnel and the adit (see, for example, Patent Documents 1 and 2). In these conventional methods, a part of the existing segment of the main tunnel, which was constructed by the shield method, is removed by thermal cutting (melting), and an opening formed in the existing segment is welded to the lining of the adit using a water-stopping steel plate or the like to ensure water-stopping properties.

JP 2013-072200 A JP 2000-291374 A

In the conventional construction method described above, connecting the main tunnel and the adit requires melting the existing segments and welding the water-stopping steel plates, which is a time-consuming process. Another issue is that the sealant of the existing segments can be damaged by the heat received during melting and welding, making it difficult to ensure sufficient water-stopping performance.

The technology disclosed herein has been developed in light of the above circumstances, and aims to improve the ease of construction when connecting the main tunnel and the adit.

The connection structure disclosed herein is characterized by comprising a plurality of connection segments that form part of the lining of the main tunnel and define a communication opening with the side tunnel, a plate member that is provided on the plurality of connection segments and defines the opening periphery of the communication opening, and a connecting frame body that includes an annular fixed flange fixed to the plate member and a cylindrical portion that extends from the periphery of the fixed flange and is fixed to the lining of the side tunnel.

It is also preferable to further include a water-stopping member interposed between the plate member and the fixed flange.

The connection segment is preferably a steel segment or a composite segment having a skin plate on the ground side, and the communication opening is preferably formed by cutting out at least a portion of the skin plate and joining the plate member to the edge of the cutout portion to form a flange, thereby opening in a predetermined shape.

The connecting segment is a steel segment or a composite segment having a pair of opposing main girders, a pair of opposing joint plates, and a skin plate attached to the periphery of the main girders and the joint plates on the ground side, and the communication opening is opened in a rectangular shape with the vertical opening edge defined by the main girders and the horizontal opening edge defined by the joint plates, and the plate member has a vertical flange provided on the edge of the main girders opposite the skin plate and extending vertically from the opening edge of the communication opening, and a horizontal flange provided on the edge of the joint plate opposite the skin plate and extending horizontally from the opening edge of the communication opening, and the fixed flange is formed in a rectangular frame shape and fixed to the surfaces of the vertical flange and the horizontal flange facing the main tunnel, and the cylindrical portion is preferably extended from the inner peripheral edge of the fixed flange toward the cross tunnel.

The connection segment is an RC segment made of concrete, and the communication opening has a rectangular opening whose vertical opening edge is defined by an edge portion extending in the circumferential direction of the RC segment and whose horizontal opening edge is defined by an edge portion extending in the axial direction of the RC segment, and the plate member has a vertical flange embedded along the edge portion extending in the circumferential direction of the RC segment and extending vertically from the opening edge of the communication opening, and a horizontal flange embedded along the edge portion extending in the axial direction of the RC segment and extending horizontally from the opening edge of the communication opening, and the fixed flange is preferably formed in a rectangular frame shape and fixed to the vertical flange and the horizontal flange.

It is also preferable to further include a first seal member extending vertically between the opposing side surfaces of the pair of connecting segments to be joined together, and a second seal member extending between the opposing side surfaces from the first seal member to the edge of the fixing flange.

It is also preferable that the cylindrical portion of the connecting frame is configured so that a water blocking wall can be installed to close the inside of the cylindrical portion.

The connection method disclosed herein is a method for connecting the main tunnel and the adit using a plurality of connection segments that form part of the lining of the main tunnel and define the communication opening with the adit, a plate member that is provided on the plurality of connection segments and defines the opening periphery of the communication opening, and a connecting frame body having an annular fixed flange fixed to the plate member and a cylindrical portion extending from the periphery of the fixed flange, and is characterized by having a removal process for removing a panel that blocks the communication opening from the plurality of connection segments, an excavation process for excavating the surrounding ground of the main tunnel from the communication opening, a main tunnel connection process for inserting at least the cylindrical portion of the connecting frame body into the communication opening and fixing the fixed flange to the plate member, and an adit connection process for fixing the cylindrical portion of the connecting frame body to the lining of the adit.

It is also preferable to further include a step of interposing a water-stopping member between the plate member and the fixed flange prior to the main tunnel connection step.

The segments of the present disclosure are characterized as being connection segments.

The technology disclosed herein can improve workability when connecting the main tunnel and the adit.

1 is a schematic vertical cross-sectional view showing a connection structure between a main tunnel and an adit according to an embodiment of the present invention. FIG. This is a schematic diagram of the connection structure of this embodiment viewed from the inside of the main tunnel. FIG. 2 is a schematic perspective view showing a connection segment according to the present embodiment. FIG. 11 is a schematic perspective view showing a connection segment according to another embodiment. FIG. 2 is a schematic perspective view showing a connecting frame body according to the present embodiment. FIG. 2 is a schematic diagram showing a water blocking wall according to the present embodiment. 5A to 5C are schematic diagrams illustrating a connection method according to the present embodiment. 5A to 5C are schematic diagrams illustrating a connection method according to the present embodiment. 5A to 5C are schematic diagrams illustrating a connection method according to the present embodiment. 5A to 5C are schematic diagrams illustrating a connection method according to the present embodiment. 5A to 5C are schematic diagrams illustrating the function of the seal member according to the embodiment. 5A to 5C are schematic diagrams illustrating a connection method according to the present embodiment. FIG. 13 is a schematic diagram showing a connection structure according to another embodiment. FIG. 11 is a schematic cross-sectional view showing a part of a connection structure according to another embodiment. FIG. 11 is a schematic perspective view showing a connection segment according to another embodiment. FIG. 11 is a schematic perspective view showing a fixing flange according to another embodiment. 13A and 13B are schematic diagrams showing connection segments according to another embodiment. FIG. 11 is a schematic perspective view showing a connection segment and a removal panel according to another embodiment. FIG. 11 is a schematic perspective view showing a connection segment and a removal panel according to another embodiment.

The connection structure, connection method, and segments according to this embodiment will be described below with reference to the attached drawings. The same components are given the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[overall structure]
Figure 1 is a schematic longitudinal cross-sectional view showing a connection structure 1 between a main tunnel 100 and a side tunnel 200 in this embodiment, and Figure 2 is a schematic view of the connection structure 1 in this embodiment as viewed from the inside of the main tunnel 100.

[Main tunnel]
The main tunnel 100 is constructed, for example, by a shield tunneling method. Specifically, the main tunnel 100 is constructed by joining a plurality of segments 10 in the tunnel circumferential direction to form a lining for one ring as shown in Figure 1, and then joining the next ring to the lining in the tunnel axial direction as shown in Figure 2, thereby constructing the entire lining. The segments 10 adjacent to each other in the tunnel axial direction are preferably joined with a predetermined offset in the tunnel circumferential direction.

Of the segments 10 of the main tunnel 100, at least the portion that forms the communication opening 300 between the main tunnel 100 and the side tunnel 200 (segments 10A, 10B) is a steel segment. The segments 10 in other parts of the main tunnel 100 are not particularly limited and may be steel segments, RC segments, or composite segments. In addition, the cross-sectional shape of the main tunnel 100 is not limited to the circular shape shown in the figure, but may be other shapes such as an ellipse or a rectangle. In the following, the segments 10A and 10B that form the communication opening 300 of each segment 10 are simply referred to as connection segments.

[Advance]
The adit 200 is constructed in a different direction (for example, perpendicular direction) to the tunnel axis direction of the main tunnel 100. The construction method of the adit 200 is not particularly limited, and it can be constructed by a jacking method or the like. The adit 200 may be a connecting tunnel that connects the main tunnel 100 to another tunnel (not shown), or may be an equipment tunnel excavated from the main tunnel 100. When the adit 200 is a connecting tunnel, it may start from the main tunnel 100 side, or may start from the other tunnel side. The cross-sectional shape of the adit 200 is also not particularly limited, and may be rectangular, circular, or elliptical. In FIG. 1, the reference numeral 210 indicates a part of the lining of the adit 200.

[Connection structure]
The connection structure 1 includes a plurality of connection segments 10A, 10B and a connection frame body 30. Of the segments 10A, 10B, the connection segment 10A defines an opening edge of the communication opening 300 extending in the tunnel axial direction (horizontal direction), and the connection segment 10B defines an opening edge of the communication opening 300 extending in the tunnel circumferential direction (vertical direction). The connection frame body 30 connects the opening periphery of the communication opening 300 defined by the connection segments 10A, 10B to the lining body 210 of the adit 200, and functions to prevent water from entering between them.

In this embodiment, the communication opening 300 is described as being opened in a substantially rectangular shape by the connection segments 10A and 10B, but it may be opened in other shapes, such as a circular or elliptical shape. In addition, the shape of the connecting frame body 30 on the main tunnel 100 side is not limited to the rectangular frame shape of the illustrated example, and if the communication opening 300 is a circular hole, it may be formed in an annular shape. In addition, the shape of the connecting frame body 30 on the side of the adit 200 side is not particularly limited, and can be set appropriately depending on the shape of the lining body 210 of the adit 200.

[Connection segment]
3 is a schematic perspective view showing the connection segments 10A and 10B according to the present embodiment. The connection segments 10A and 10B include a pair of main girders 11A and 11B, a pair of joint plates 12A and 12B, a skin plate 13, a plurality of longitudinal ribs 14, and fixing flanges 15 and 16.

Each of the main girders 11A, 11B is formed as an arc-shaped plate extending approximately parallel to the circumferential direction of the tunnel, and is arranged facing each other at a distance in the tunnel axial direction. If the cross section of the main tunnel 100 (see Figure 1) is rectangular, the main girders 11A, 11B may be formed as rectangular plates.

At predetermined locations on the main girders 11A and 11B, a plurality of through holes 18 penetrating in the tunnel axis direction are provided at predetermined intervals in the circumferential direction. Bolts (not shown) are inserted into these through holes 18 to secure adjacent segments in the tunnel axis direction. Of the main girders 11A and 11B, a bolt (not shown) is inserted into the through hole 18 of the main girder 11A, where the fixing flange 16 shown in FIG. 3(B) is provided, to secure the removable panel 40 (see FIG. 7), which will be described later.

Each joint plate 12A, 12B is formed as a rectangular plate extending between the ends of the main girders 11A, 11B in the tunnel axis direction, and is arranged facing each other at a distance in the tunnel circumferential direction. The axial ends of the joint plates 12A, 12B and the circumferential ends of the main girders 11A, 11B are joined to each other by welding or the like.

A number of through holes 19 that penetrate in the circumferential direction of the tunnel are provided at predetermined locations of the joint plates 12A and 12B at predetermined intervals in the axial direction. Bolts (not shown) are inserted into the through holes 19 to secure adjacent segments in the circumferential direction of the tunnel. Of the joint plates 12A and 12B, a bolt (not shown) is inserted into the through hole 19 of the joint plate 12A, which is provided with the fixing flange 15 shown in FIG. 3(A), to secure the removable panel 40 (see FIG. 7), which will be described later.

The skin plate 13 is formed in a plate shape that is curved with the same curvature as the outer periphery of the arc of the main girders 11A, 11B. The skin plate 13 is joined by welding or the like to the edge of the main girders 11A, 11B and the joint plates 12A, 12B on the outer side of the arc of the main girders 11A, 11B (the natural ground side). If the cross section of the main tunnel 100 (see Figure 1) is rectangular, the skin plate 13 may be formed in a substantially flat plate shape.

The multiple vertical ribs 14 span between the main girders 11A and 11B in the tunnel axis direction and are arranged at a predetermined interval around the tunnel. The ends of the vertical ribs 14 in the tunnel axis direction are preferably joined to the opposing side surfaces of the main girders 11A and 11B by welding or the like.

[Sealing member]
Two circumferential seal members 20A, 20B (first seal members of the present disclosure) are provided on the outer side (back surface of the opposing side) of each of the main girders 11A, 11B, extending approximately parallel to the circumferential direction of the tunnel across the through hole 18. The circumferential seal members 20A, 20B are formed of, for example, a swelling resin material, and are preferably attached by being fitted into grooves (not shown) recessed in the outer sides of the main girders 11A, 11B.

Two axial seal members 21A, 21B are provided on the outer surface (back surface of the opposing side surface) of each joint plate 12A, 12B, which extend approximately parallel to the tunnel axis direction and sandwich the through hole 19. These axial seal members 21A, 21B are formed, for example, from a swelling resin material, and are preferably attached by being fitted into grooves (not shown) recessed into the outer surfaces of the joint plates 12A, 12B.

The circumferential seal members 20A, 20B and the axial seal members 21A, 21B are joined at their corresponding ends. In other words, these seal members 20A, 20B, 21A, 21B form a double seal structure that is continuous in an annular shape around the outer surfaces of the main girders 11A, 11B and the joint plates 12A, 12B.

When the segments 10 are joined together, the circumferential seal members 20A, 20B of one segment 10 are pressed against the circumferential seal members 20A, 20B of the other segment 10 joined in the tunnel axial direction, and the axial seal members 21A, 21B of one segment 10 are pressed against the axial seal members 21A, 21B of the other segment 10 joined in the tunnel circumferential direction, effectively preventing the infiltration of water that would flow through the gaps between the segments 10 from the ground side.

Two radial seal members 23A, 23B are provided on the outer surface of each of the main girders 11A, 11B. More specifically, in the connection segment 10A shown in FIG. 3(A), two radial seal members 23A, 23B are provided at the tunnel circumferential end of each of the main girders 11A, 11B, one end adjacent to the joint plate 12A on which the fixing flange 15 described later is provided. In addition, in the connection segment 10B shown in FIG. 3(B), two radial seal members 23A, 23B are provided at both circumferential ends of the main girder 11A on which the fixing flange 16 described later is provided.

These radial seal members 23A, 23B are formed, for example, from a swellable resin material, and are preferably attached by being fitted into grooves (not shown) recessed into the outer surfaces of the main girders 11A, 11B. When the connection segment 10A and the connection segment 10B are joined so that the ends of the fixing flanges 15, 16 are aligned, the radial seal members 23A, 23B of the connection segment 10A and the radial seal members 23A, 23B of the connection segment 10B are pressed against each other.

In this embodiment, the radial seal members 23A, 23B include a first radial seal member 23A_1, _{23B_1} extending from the circumferential seal member 20B on the natural ground side to the circumferential seal member 20A on the inside of the tunnel, and a second radial seal member _{23A_2} , _{23B_2} (second seal member of the present disclosure) extending from the circumferential seal member 20A on the inside of the tunnel to the end edges of each flange 15, 16. Of these, the second radial seal members _{23A_2} , _{23B_2} function to prevent the intrusion of water _that passes through a gap between a tubular body portion 35 (see FIG. 5) of a connecting frame body 30 (described later) and a joint plate 12A from the natural ground side and tries to flow circumferentially between each main girder 11A, 11B.

[Flange]
The connection segment 10A shown in Fig. 3(A) is provided with a first fixing flange 15 (horizontal flange) extending in the tunnel axial direction (horizontal direction). Specifically, the first fixing flange 15 is formed in a long plate shape having a length approximately equal to the tunnel axial direction length of the joint plates 12A, 12B, and is provided on one of the joint plates 12A, 12B (joint plate 12A in the illustrated example). The first fixing flange 15 protrudes from the end edge of the joint plate 12A on the tunnel inner side (opposite the skin plate 13) toward the opposing direction of the joint plates 12A, 12B so as to form an approximately L-shape with the joint plate 12A.

The length of the first fixing flange 15 in the tunnel circumferential direction (flange width) is not particularly limited, and can be set appropriately depending on the size of the first fixed flange 32 (see FIG. 5) of the connecting frame body 30 described later. In addition, the method of connecting the first fixing flange 15 and the joint plate 12A is also not particularly limited, and their peripheral edges may be joined together by welding or the like, or they may be formed integrally by extending the joint plate 12A and bending it into a roughly L-shape.

A number of through holes 15E that penetrate in the tunnel radial direction are provided at predetermined locations on the first fixing flange 15 at predetermined intervals in the tunnel axial direction. Bolts (not shown) for fixing the first fixed flange 32 (see FIG. 5) of the connecting frame body 30 are inserted into these through holes 15E.

Two axial grooves 15A, 15B are recessed in the flange surface (the surface opposite to the surface facing the skin plate 13) of the first fixed flange 15, which extend approximately parallel to the tunnel axial direction and sandwich the through hole 15E. The ends of the axial grooves 15A, 15B are respectively continuous with grooves (not shown) into which the above-mentioned second radial seal members _{23A_2} , _{23B_2} are fitted. Annular seal members 25A, 25B (see FIG. 8), which will be described later, are fitted and attached in the axial grooves 15A, 15B, respectively.

The connecting segment 10B shown in FIG. 3(B) is provided with a second fixing flange 16 (vertical flange) that extends in the tunnel circumferential direction (vertical direction). Specifically, the second fixing flange 16 is formed in a strip shape that curves with the same curvature as the inner arc circumference of the main girders 11A, 11B, and is provided on one of the main girders 11A, 11B (main girder 11A in the illustrated example). The second fixing flange 16 protrudes from the edge of the inner arc circumference side of the main girder 11A (the side opposite the skin plate 13) toward the opposing direction of the main girders 11A, 11B so as to form a roughly L-shape with the main girder 11A.

The length of the second fixing flange 16 in the tunnel circumferential direction is not particularly limited, and can be set to an appropriate length depending on the opening dimensions of the communication opening 300 (see Figures 1 and 2). The length of the second fixing flange 16 in the tunnel axial direction (flange width) is also not particularly limited, and can be set appropriately depending on the size of the second fixed flange 33 (see Figure 5) of the connecting frame body 30 described later. In addition, the method of connecting the second fixing flange 16 and the main girder 11A is also not particularly limited, and their peripheral edges may be joined to each other by welding or the like, or they can be formed integrally by extending the main girder 11A and bending it into an approximately L-shape.

A number of through holes 16E that penetrate in the tunnel radial direction are provided at predetermined locations on the second fixing flange 16 at predetermined intervals in the tunnel circumferential direction. Bolts (not shown) for fixing the second fixed flange 33 (see FIG. 5) of the connecting frame body 30 are inserted into these through holes 16E.

Two circumferential grooves 16A, 16B extending approximately parallel to the tunnel circumferential direction are recessed in the flange surface of the second fixed flange 16 (the surface opposite to the surface facing the skin plate 13) sandwiching the through hole 16E. In addition, two axial grooves 16C, 16D extending in the tunnel axial direction from both ends of the circumferential grooves 16A, 16B to the outer surface of the main girder 11A are recessed in the flange surface of the second fixed flange 16. The ends of the axial grooves 16C, 16D are continuous with grooves (not shown) into which the above-mentioned second radial seal members _{23A_2} , _{23B_2} are fitted.

When the connection segments 10A, 10B are joined together, the ends of the axial grooves 16C, 16D of the second fixed flange 16 are continuous with the axial grooves 15A, 15B of the first fixed flange 15. Annular seal members 25A, 25B (see FIG. 8), which will be described later, are fitted into these axial grooves 15A, 15B, 16C, 16D and circumferential grooves 16A, 16B, respectively. These annular seal members 25A, 25B are made of a swelling resin material or the like, and seal the gap between the fixed flanges 15, 16 and the fixed flanges 32, 33 (see FIG. 5).

In addition, while FIG. 3(B) shows an example in which one connection segment 10B constitutes the opening edge of the communication port 300 in the tunnel circumferential direction (vertical direction), two connection segments 10B can also be joined together in the tunnel circumferential direction. In this case, as shown in FIG. 4, one end of the second fixing flange 16 is extended to the joint plates 12A, 12B (joint plate 12A in the illustrated example), and radial seal members 23A, 23B are provided on the outer surface of the joint plate 12A.

[Connected frame]
FIG. 5 is a schematic perspective view showing the connecting frame body 30 according to the present embodiment.

The connecting frame body 30 comprises a rectangular frame-shaped fixed flange 31 and a cylindrical portion 35 extending from the inner peripheral edge of the fixed flange 31.

The cylindrical portion 35 is formed in a square cylindrical shape with a smaller diameter than the communication port 300. The tip 35A of the cylindrical portion 35 is fixed to the lining body 210 of the cross tunnel 200 (see FIG. 1). The length of the cylindrical portion 35 in the cylindrical axial direction is not particularly limited, and can be an appropriate length depending on the distance between the communication port 300 and the lining body 210. The method of fixing the tip 35A of the cylindrical portion 35 to the lining body 210 is also not particularly limited, and they may be joined by bolting or welding, etc. When the tip 35A and the lining body 210 are bolted together, it is preferable to interpose a seal member between them.

The fixed flanges 31 extend outward from the base end of the tubular portion 35 and include a pair of first fixed flanges 32 extending in the tunnel axial direction and a pair of second fixed flanges 33 extending in the tunnel circumferential direction.

The pair of first fixed flanges 32 are spaced apart in the tunnel circumferential direction by the opening height of the communication opening 300, and the pair of second fixed flanges 33 are spaced apart in the tunnel axial direction by the opening width of the communication opening 300. The first fixed flanges 32 and the second fixed flanges 33 form a fixed flange 31 that opens in a rectangular shape that is approximately the same as the communication opening 300.

The first fixed flange 32 has a plurality of insertion holes 37 for inserting bolts (not shown) at positions corresponding to the through holes 15E (see FIG. 3A) of the first fixed flange 15. The second fixed flange 33 has a plurality of insertion holes 38 for inserting bolts (not shown) at positions corresponding to the through holes 16E (see FIG. 3B) of the second fixed flange 16. In other words, the connecting frame body 30 is configured to be connected to each of the segments 10A and 10B on the main tunnel 100 side by fastening the first fixed flange 32 to the first fixed flange 15 and the second fixed flange 33 to the second fixed flange 16 with bolts.

In this embodiment, the connecting frame body 30 is adapted to be provided with a water blocking wall 50 as shown in FIG. 6. The water blocking wall 50 may be, for example, as shown in FIG. 6(A), a plurality of steel plates 51 stacked on the bottom surface of the connecting frame body 30, or as shown in FIG. 6(B), an opening 54 may be provided in a steel plate 52 that closes the connecting frame body 30, and an iron door 53 that can open and close the opening 54 may be provided.

[Connection method]
Next, the connection method according to this embodiment will be described in detail with reference to FIGS.

In the first step (the removal step of the present disclosure), as shown in FIG. 7, with the removal panels 40 attached to each of the connection segments 10A, 10B of the main tunnel 100, ground improvement is carried out on the surrounding ground by injecting chemicals or the like. Once ground improvement has been carried out, the removal panels 40 are removed and removed, and a predetermined amount of the surrounding ground (for example, a space capable of receiving the tubular portion 35 of the connecting frame body 30) is excavated from the communication opening 300. Note that ground improvement may be omitted if the surrounding ground has sufficient strength depending on the condition of the ground.

Here, the removal panel 40 closes the communication opening 300 defined by each of the connection segments 10A, 10B, and constitutes part of the lining of the main tunnel 100. The removal panel 40 is formed, for example, in the shape of an arc plate curved with approximately the same curvature as each of the segments 10A, 10B, and its periphery is fixed to the joint plate 12A of the connection segment 10A and the main girder 11A of the connection segment 10B by bolts or the like (not shown). The removal panel 40 may be composed of multiple panels as in the illustrated example, or may be composed of one panel. The specific number and shape of the removal panel 40 may be set appropriately according to the size and shape of the communication opening 300.

In this way, the connecting segments 10A and 10B define a communication opening 300 at the location of the lining of the main tunnel 100 where the connection to the adit 200 is planned, and the communication opening 300 is closed by the removable panel 40, so that the connection work for the adit 200 can be started simply by removing the removable panel 40. This eliminates the need for opening work such as melting the segments, which was required in the conventional construction method, and reliably improves workability. It also makes it possible to effectively prevent deterioration and damage to the sealing members 20A, 20B, 21A, and 21B (see Figure 3) of the existing segments 10A and 10B due to melting.

In the second step, as shown in FIG. 8, annular seal members 25A, 25B (one example of a water-stopping member of the present disclosure) are attached to the fixed flanges 15, 16 of the connection segments 10A, 10B. The annular seal members 25A, 25B may be attached by fitting them into the grooves of the fixed flanges 15, 16, or may be attached to the flange surfaces of the fixed flanges 15, 16 with adhesive or the like. In this case, since the flange surfaces of the fixed flanges 15, 16 are exposed to the inside of the main tunnel 100, soil and sand from the ground are unlikely to adhere to them, and the worker can easily and quickly install the annular seal members 25A, 25B without cleaning the flange surfaces. Once the annular seal members 25A, 25B are installed, the process proceeds to the third step.

The number of annular sealing members 25A, 25B is not limited to two as shown in the illustrated example, and may be one, or three or more. The water-stopping members are not limited to the annular sealing members 25A, 25B, and may be applied by caulking. When caulking is used, the annular sealing members 25A, 25B may be omitted, or caulking and the annular sealing members 25A, 25B may be used together.

In the third step (the main tunnel connection step of the present disclosure), as shown in FIG. 9, the tubular portion 35 of the connecting frame body 30 is inserted into the communication opening 300 from the inside of the main tunnel 100, and the fixed flange 31 is abutted against the fixed flanges 15, 16. Next, as shown in FIG. 10, the fixed flange 31 and the fixed flanges 15, 16 are fixed by bolting, completing the connection work between the segments 10A, 10B of the main tunnel 100 and the connecting frame body 30. In this way, by connecting the main tunnel 100 and the connecting frame body 30 by bolting each flange 15, 16, 31, the welding work between the segments and the waterstop plate as in the conventional construction method is unnecessary, and the workability can be reliably improved. In addition, it is possible to effectively prevent damage to the sealing member due to the heat of welding.

Here, as shown in Fig. 11, when the fixed flange 31 is fixed to the fixed flange 15 (16), the annular seal members 25A, 25B are interposed in a pressure-contact state in the opposing space. Also, in the gap between the circumferential seal member 20A on the inside of the tunnel provided on the main girders 11A, 11B and the back surface of the fixed flange 31, the second radial seal members _{23A_2} , _{23B_2} connecting the circumferential seal member 20A and the annular seal members 25A, 25B are interposed.

That is, water that passes through the gap between the cylindrical portion 35 and each segment 10A, 10B and flows between the fixed flange 31 and the fixed flange 15 (16) (see dashed arrow W1 in FIG. 11) is doubly stopped by the two annular seal members 25A, 25B, and water that flows into the gap between the adjacent main girders 11A, 11B (see dashed arrow W2 in FIG. 11) is doubly stopped by the two second radial seal members _{23A_2} , _{23B_2} . This makes it possible to reliably prevent water from entering the main tunnel 100 from the natural ground side. In addition, since the joint between the fixed flange 31 and the fixed flange 15 (16) is exposed inside the main tunnel 100, if a problem such as water leakage occurs after construction, it is possible to perform caulking work or the like at the relevant location from the main tunnel 100 side, which has a larger space.

Finally, in the fourth step, the tip 35A of the connecting frame body 30 is connected to the lining 210 of the adit 200, completing the connection work between the main tunnel 100 and the adit 200. The tip 35A and the lining 210 of the adit 200 may be connected by bolting if they are approximately the same shape, or, if the tip 35A and the lining 210 have different shapes, they may be connected by inserting a flange (not shown) between them and joining the flange by welding or the like.

Once the connection of the connecting frame body 30 is completed, as shown in FIG. 12, it becomes possible to install the water blocking wall 50 on the tubular portion 35 of the connecting frame body 30. In this way, if the water blocking wall 50 is installed early after the connecting frame body 30 is connected, it becomes possible to reliably ensure safety in the event of flooding or the like occurring as the cross tunnel 200 is excavated thereafter. Furthermore, by making it possible to install the water blocking wall 50 on the connecting frame body 30, it becomes possible to ensure safety even in cases where, for example, the diameter of the main tunnel 100 is large and the water blocking wall 50 cannot be installed on the main tunnel 100 side.

The connection structure 1 of this embodiment described above includes a plurality of connection segments 10A, 10B that form part of the lining of the main tunnel 100 and define the communication opening 300 with the cross tunnel 200, fixed flanges 15, 16 that are provided on the connection segments 10A, 10B and surround the opening edge of the communication opening 300, a fixed flange 31 that is fixed to the fixed flanges 15, 16, and a connecting frame body 30 that has a cylindrical portion 35 that extends from the edge of the fixed flange 31.

When connecting the main tunnel 100 and the adit 200, the removal panels 40 are removed from the connecting segments 10A and 10B, the surrounding ground is excavated, the tubular portion 35 of the connecting frame body 30 is inserted into the communication opening 300, the fixed flange 31 is fixed to the fixing flanges 15 and 16, and the tip portion 35A of the tubular portion 35 is fixed to the lining body 210 of the adit 200, thereby completing the connection work between the main tunnel 100 and the adit 200.

This eliminates the need to melt-cut existing segments or weld water-stopping steel plates, which was previously required, and ensures that construction work can be completed more efficiently while also shortening construction time. It also prevents damage to sealing materials caused by heat from melt-cutting and welding, and ensures improved water-stopping performance. Furthermore, installing a water-stopping wall 50 on the connecting frame body 30 can improve safety.

[others]
The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present disclosure.

For example, in the above embodiment, the annular seal members 25A, 25B are described as being attached to the fixed flanges 15, 16 on the segment 10A, 10B side, but it is also possible to attach the annular seal members 25A, 25B in advance to the fixed flange 31 side of the connecting frame body 30.

In addition, the number of sealing members 20A, 20B, 21A, 23A, 23B, 25A, and 25B has been described as two each, but the number may be one, or three or more.

Although the fixed flange 31 has been described as being attached to the fixing flanges 15, 16 exposed on the inside of the main tunnel 100, it can also be configured to be attached to the outer periphery (natural ground side) of the main tunnel 100 as shown in Figure 13. In this case, the fixed flange 31 is formed by bending inward from the cylindrical portion 35, and the fixed flange 31 is fixed to the skin plate 13 of the connecting segments 10A, 10B. As shown in Figure 14, a through hole 13A for inserting a bolt is drilled in the skin plate 13, and it is desirable to previously fix a nut 13N to the back surface of the through hole 13A (the surface on the inside of the tunnel) by welding or the like.

In the above embodiment, the fixing flanges 15, 16 and the fixed flange 31 are described as being fixed by bolting, but they can also be joined by welding. In this case, too, the flanges can be welded together in a straight line, which improves workability compared to the conventional method of welding a water-stopping steel plate to the melted parts of the existing segments.

The connecting segments 10A, 10B are not limited to steel segments, and RC segments can also be used. When using RC segments, the fixing flange 16 (15) can be embedded in concrete C as shown in Figures 15(A) and (B). Here, Figure 15(A) shows an example in which the fixed flange 31 is attached from the inside of the tunnel, and Figure 15(B) shows an example in which the fixed flange 31 is attached from the outside of the tunnel. When embedding the fixing flange 16 (15) in concrete C, as shown in Figure 16, a nut 16N can be attached by welding or the like to the back of the through hole 16E (see Figure 15) of the fixing flange 16, and an anchor 16H can be provided extending from the nut 16N.

The connecting segments 10A, 10B are not limited to steel segments or RC segments, and composite segments can also be used. In the composite segment, when the fixed flange 31 is attached from inside the tunnel, as shown in FIG. 17(A), the fixing flange 16 (15) with a nut (not shown) on the back of the through hole 16E is attached to the main girder 11A (or joint plate 12A), and the fixing flange 16 (15) is embedded so that it is approximately flush with the concrete C. When the fixed flange 31 is attached from outside the tunnel, as shown in FIG. 17(B), a nut 13N and an anchor 13H are provided on the back of the through hole 13A of the skin plate 13, and the skin plate 13 is embedded in the concrete C.

The shape of the communication opening 300 is not limited to the rectangular shape of the above embodiment, but may be a circle as shown in FIG. 18 or a polygon as shown in FIG. 19. When using a circle as shown in FIG. 18, the fixing flange 15 (16) can be formed in a semicircular arc, and the removal panel 40 can be formed in a semicircular shape. When using a polygon as shown in FIG. 19, the fixing flange 15 (16) and the removal panel 40 can also be formed in a polygonal shape.

REFERENCE SIGNS LIST 1 Connection structure 10 Segment 10A, 10B Connection segment 11A, 11B Main girder 12A, 12B Joint plate 13 Skin plate 14 Longitudinal rib 15, 16 Fixation flange 20A, 20B Circumferential seal member (first seal member)
21A, 21B Axial seal members 23A, 23B Radial seal members _{23A_1} , _{23B_1} First radial seal member _{23A_2} , _{23B_2} Second radial seal member (second seal member)
25A, 25B Annular seal member 30 Connecting frame body 31 Fixed flange 32 First fixed flange 33 Second fixed flange 35 Cylindrical body portion 40 Removable panel 50 Water cutoff wall 100 Main tunnel 200 Adit tunnel 300 Communication port

Claims (10)

A plurality of connection segments that constitute a part of the lining of the main tunnel and are constructed in a different direction from the tunnel axis direction of the main tunnel to define a communication opening with a side tunnel that forms a connecting tunnel or equipment tunnel;
a plate member provided on the plurality of connection segments and defining an opening periphery of the communication port;
A connection structure comprising: an annular fixed flange fixed to the plate member forming the opening periphery of the communication port; and a connecting frame body including a cylindrical portion whose base end is fixed to the periphery of the fixed flange and whose tip side is fixed to the lining of the cross tunnel. The connection structure according to claim 1 , further comprising a water-stopping member interposed between the plate member and the fixed flange. The connection segment is a steel segment or a composite segment having a skin plate on the ground side,
The connection structure according to claim 1 or 2, wherein the communication opening is formed by cutting out at least a portion of the skin plate and joining the plate member to an edge of the cut-out portion to form a flange, thereby opening in a predetermined shape. The connection segment is a steel segment or a composite segment having a pair of main girders facing each other, a pair of joint plates facing each other, and a skin plate attached to the peripheral edges of the main girders and the joint plates on the ground side,
The communication port has a vertical opening edge defined by the main girder and a horizontal opening edge defined by the joint plate, and opens in a rectangular shape,
the plate member has a vertical flange provided on an edge of the main girder opposite to the skin plate and extending vertically along an opening edge of the communication port, and a horizontal flange provided on an edge of the joint plate opposite to the skin plate and extending horizontally along an opening edge of the communication port,
The fixed flange is formed in a rectangular frame shape and is fixed to the surfaces of the vertical flange and the horizontal flange facing the main tunnel,
The connection structure according to claim 1 or 2, wherein the cylindrical portion extends from an inner peripheral edge of the fixed flange toward the adit. The connection segment is an RC segment made of concrete,
The communication port has a vertical opening edge defined by an edge portion of the RC segment extending in the circumferential direction of the well, and a horizontal opening edge defined by an edge portion of the RC segment extending in the well axis direction, and opens in a rectangular shape;
The plate member has a vertical flange embedded along an edge of the RC segment extending in a circumferential direction of the well and extending vertically along an opening edge of the communication port, and a horizontal flange embedded along an edge of the RC segment extending in a axial direction of the well and extending horizontally along an opening edge of the communication port,
The connection structure according to claim 1 or 2, wherein the fixed flange is formed in a rectangular frame shape and is fixed to the vertical flange and the horizontal flange. a first seal member extending vertically between opposing side surfaces of the pair of connecting segments to be joined together;
The connection structure according to claim 1 , further comprising: a second seal member extending between the opposing side surfaces from the first seal member to an edge of the fixing flange. The connection structure according to claim 1 , wherein a water blocking wall that blocks an interior of the cylindrical portion of the connecting frame body is configured to be able to be installed in the cylindrical portion of the connecting frame body. A connection method for connecting the main tunnel and the adit tunnel using a plurality of connection segments which form part of the lining of the main tunnel and which define a communication opening with an adit tunnel which is constructed in a different direction from the tunnel axis direction of the main tunnel and which forms a connecting tunnel or equipment tunnel, a plate member which is provided on the plurality of connection segments and which defines the opening periphery of the communication opening , an annular fixed flange which is fixed to the plate member which forms the opening periphery of the communication opening, and a connecting frame body which has a cylindrical portion whose base end is fixed to the periphery of the fixed flange and which extends from the periphery ,
a removal process of removing a panel that closes the communication opening from the plurality of connection segments;
an excavation step of excavating surrounding natural ground of the main tunnel from the communication port;
a main tunnel connecting step of inserting at least the cylindrical portion of the connecting frame body into the communication port and fixing the fixed flange to the plate member;
and an adit connecting step of fixing a tip side of the cylindrical portion of the connecting frame body to a lining body of the adit. The connection method according to claim 8, further comprising a step of interposing a water-stopping member between the plate member and the fixed flange prior to the main tunnel connection step. A connecting segment according to any one of claims 1 to 7.

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