JP2015117546A - Structure and method for tunnel connection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure and a method for tunnel connection that reduce the bending moment at the joint position of a tunnel connection, with a simple and low-cost structure.SOLUTION: A structure for tunnel connection includes a joint segment 30, on which a first single-circle segment (a single-circle segment) is connected to a first joint end surface and both a connecting segment and a second single-circle segment (joint single-circle segment) 12A are connected to a second joint end surface 32. When the second single-circle segment 12A is connected to the joint segment 30, a pair of first single-circle main girders 13A and a second single-circle main girder 13B are connected to the second joint end surface 32. When a connecting segment is connected to the joint segment 30, the pair of first single-circle main girders 13A is removed from the second joint end surface 32, and a pair of connecting main girders of the connecting segment are connected to the position where the pair of first single-circle main girders 13A were connected.

Description

  The present invention relates to a tunnel connection structure and a tunnel connection method for connecting a tunnel constructed in advance by a shield method and another tunnel.

  Conventionally, as a tunnel structure for connecting a plurality of adjacent tunnels constructed by a shield construction method, an outer shell portion (support structure) between shield tunnels constructed in advance as described in Patent Document 1 A widened structure is generally known in which a large section underground space is constructed by excavating a natural ground inside the supporting structure.

  In the widened structure as in Patent Document 1, for example, as shown in FIG. 19, a connecting segment joining recess 4a in which a temporary compensation case 41 is detachably attached to the outer surface of a segment constituting the shield tunnels 4A and 4B is formed. By filling the temporary filling case 41 with a filler, the connection segment bonding recess 4a can be temporarily filled.

  In this case, when joining the connection segments to the shield tunnels 4A and 4B, by fitting the end portions of the connection segments into the connection segment joining recesses 4a and joining the segments together, both shield tunnels 4A, The widening structure by which the widening lining by the connection segment was extended between 4B was cut and expanded.

Japanese Patent No. 4782704

However, the conventional tunnel connection structure has the following problems.
That is, in the conventional widened structure, since it is necessary to provide notches (recesses 4a for connecting segment joining) on the outer surfaces of the segments of the shield tunnels 4A and 4B in FIG. There was a problem that the cost increased.

  In addition, during construction of the shield tunnel, the notch of the segment assembled immediately after tunnel excavation is filled with filler, but due to the tunnel structure, a large bending moment acts on the joint position of the connection, resulting in the generated cross-sectional force. Becomes larger. Therefore, there is a problem that the design of the connecting portion between the segments becomes excessive and the cost increases, and there is room for improvement in that respect.

  The present invention has been made in view of the above-described problems, and provides a tunnel connection structure and a tunnel connection method capable of reducing a bending moment at a joint position of a connection portion between tunnels with a simple and low-cost structure. The purpose is to do.

In order to achieve the above object, the tunnel connection structure according to the present invention is a connection that forms a tunnel different from the single-circle tunnel with respect to a plurality of single-circle segments that form a single-circular tunnel constructed in advance. A tunnel connection structure for connecting segments, wherein the plurality of single circle segments are provided to be inserted into at least a part of the tunnel circumferential direction, and the single circle is formed on a first junction end face at one end in the tunnel circumferential direction. A segment is connected, and a joint segment in which both the connection segment and the single-circle segment are connected to the second joint end surface at the other end;
Of the plurality of single circle segments, at least a joint single circle segment that is directly connected to the second joint end surface includes a pair of first single circle main girders respectively disposed at both ends in the tunnel axis direction, and the pair of first circle segments. A second single circle main girder arranged between one single circle main girder, and the connection segment has a pair of connection main girder respectively arranged at both ends in the tunnel axis direction, and the joint The joint single-circle segment is connected to the second joint end face of the segment first, and then the joint single-circle segment is removed and the connection segment is connected, and the joint single-circle is connected to the joint segment. When the segment is connected, the pair of first single circle main girders and the second single circle main girder are connected to the second joint end face, and when the connection segment is connected to the joint segment, the pair The first and single circular main beam is removed, the pair of connecting main beam to a second pair of first single circle main beam of the joining end face has been connected position, characterized in that it is connected.

  Further, the tunnel connection method according to the present invention is a tunnel connection method using the tunnel connection structure described above, wherein the junction segment is inserted in at least a part of the circumferential direction of the single circle segment, and the junction segment The single circle segment is connected to the first joint end surface of the ring, and the first single circle main girder and the second single circle main girder of the single circle segment are connected to the second joint end surface to form a ring-shaped unit. Constructing a circular tunnel, removing the first single circle main girder from the second joint end face, and at the position where the first single circle main girder of the second joint end face is connected, Connecting a connecting main girder and connecting the connecting segment to the joining segment.

In the present invention, when constructing a single circle tunnel, the first single circle main beam and the second single circle main beam of the bonded single circle segment are connected to the second bonded end surface of the bonded segment, and the connection segment is bonded to the bonded segment. When the first single circle main girder is removed and the second single circle main girder is connected to the joining segment, the connection main girder of the connection segment is connected to the position where the first single circle main girder was connected. Therefore, it is possible to connect the connection segment to the junction segment without causing the connection main beam of the connection segment to interfere with the second single circle main beam of the junction single circle segment.
And since it is possible to connect the main girders without interfering with each other, after securing the stability of the surrounding ground of the joint part, the single circle segment connected to the joint segment is removed, and the remaining single circle A large underground space in which an outer shell is formed by the segments and the connecting segments can be constructed.

  In addition, in the present invention, the joining segment is not a segment having a complicated structure with a special notch as in the prior art, but has a simple structure and an excessive bending moment like a segment having a notch is provided. There is an advantage that it does not work.

  Further, in the tunnel connection structure according to the present invention, an adjacent single circle segment to be bonded adjacent to the bonded single circle segment among the single circular segments is provided with a joint plate at an end portion on the bonded single circular segment side. An end plate facing the joint plate is provided closer to the joint single circle segment than an intermediate portion in the tunnel circumferential direction of the adjacent single circle segment, and a stiffener for connecting the joint plate and the end plate is provided. It is preferable to be provided.

  When the first main girder of the joined single circle segment is removed from the second joined end face, the load transmitted from the joined single circle segment to the adjacent single circle segment is transmitted only from the second single circle main girder of the joined single circle segment. Therefore, the load is concentrated and transmitted to the adjacent single circle segment. Therefore, in the present invention, the stiffener and the end plate are provided in the adjacent single circle segment, so that the adjacent single circle segment has high rigidity, and even if the load is concentrated and transmitted, the load is displaced or deformed. This load can be reliably transmitted into the ring of the single-circular tunnel.

In the tunnel connection structure according to the present invention, the second single circle main girder has a bending moment that is applied by earth pressure from the ground and a strength against an axial force in the circumferential direction of the tunnel. It is preferable that the strength is greater than the bending moment acting by the earth pressure from the natural ground side and the axial force in the circumferential direction of the tunnel.
The second single circle main girder acts on the bending moment acting on the earth pressure from the natural ground side and the strength against the axial force in the circumferential direction of the tunnel by the earth pressure from the natural mountain side of the first single circular main girder. It is preferably at least twice the strength against the bending moment and the axial force in the tunnel circumferential direction.

  By adopting such a configuration, even when the first single circle main girder of the joined single circle segment is removed, the bending moment and the axial force in the circumferential direction of the tunnel acting due to earth pressure from the natural ground side, The second single circle main girder can surely counter.

  In the tunnel connection structure according to the present invention, the joint segment and the single-circle segment connected to the first joint end face and the second joint end face of the joint segment are respectively on the ground side in the tunnel radial direction. It is preferable that the outer peripheral surface position is coincident in the tunnel circumferential direction.

By adopting such a configuration, the single-circular tunnel has a structure without a notch in which the position of the outer peripheral surface of the tunnel on the ground mountain side coincides, and the outer peripheral surfaces of the individual single-circle segments connected in the circumferential direction of the tunnel are all around. Therefore, a structure that does not receive an excessive bending moment as described above can be realized more reliably.
Also, when constructing a single circle tunnel by the shield method, since there is no notch, the gap between the cylindrical shield inner surface of the shield machine and the outer surface of the single circle tunnel (single circle segment) can be minimized, It becomes possible to ensure water tightness during construction (that is, water tightness due to a tail seal).

  In the tunnel connection structure according to the present invention, an end plate facing the second joint end face is provided at an intermediate portion in the tunnel circumferential direction of the joint segment or the first joint end face, and the second joint end face is provided. It is preferable that a stiffening material for connecting the joining plate and the end plate is provided.

  By adopting such a configuration, the axial force in the circumferential direction of the tunnel due to the connecting segment or single circular segment can be transmitted to the entire single circular tunnel via the end plate from the stiffener provided on the joint plate of the joint segment. it can.

  In the tunnel connection structure according to the present invention, the first single circle main girder, the second single circle main girder, and the connection main girder are connected to an end surface connected to the second joint end surface, respectively. Connected to the second joint end face via the connection plate, and connected to the second joint end face of the joint segment, the first single circular main beam, and the second single piece. The connecting plates connected to the circular main girder are respectively provided with a joining seal groove, a first single-circular seal groove, and a second single-circular seal groove continuously in the tunnel axial direction at the same tunnel radial direction position. A joining seal material, a first single-circle seal material, and a second single-circle seal material are continuously provided along the seal groove, and the joining seal material and the first single-circle seal materials, and the joining seal material, The second single circular sealing materials are in the tunnel axis direction. The connection plate that is in contact with the connection main girder is continuously provided with a connection seal groove at the same position in the radial direction of the tunnel as the first single-circle seal groove, and extends along the connection seal groove. And a connection plate connected to the connection main beam by removing the first single circular main beam and the connection plate connected to the first single circular main beam from the joint segment. In a state where the joining segment is connected to the connecting segment via the second sealing member, the second single-circle sealing material and the connecting sealing material are continuous in the tunnel axis direction, and a seal structure that is in contact with the joining sealing material It is preferable to have.

  In the tunnel connection method according to the present invention, the first single circle main girder, the second single circle main girder, and the connection main girder are connected to end surfaces connected to the second joint end surfaces, respectively. And connected to the second joint end face via the connection plate, and before the connection segment is connected to the second joint end face of the joint segment, provided on the second joint end face. Seals provided on the connection plate connected to the first single-circle main girder, and seal plates provided on the second joint end surface and the connection plate connected to the second single-yield main girder After the sealing material provided in the contact part is continuously brought into contact with each other in the tunnel axis direction and the connection segment is connected to the second joint end face of the joint segment, the seal material is connected to the removed first single circle main girder. Before being inserted instead of the connected connecting plate A seal material provided on a connection plate connected to a connection main beam and a seal material provided on a connection plate connected to the remaining second single circle main beam are continuously provided in the tunnel axis direction, The connecting plate connected to the second single circular main girder, the sealing material provided on the connecting plate connected to the connecting main girder, and the sealing material provided on the joining segment are located in the same tunnel radial direction position. It is preferable to make it contact | abut continuously in a tunnel axial direction.

  By doing in this way, the seal structure for preventing the infiltration of groundwater into the tunnel is the same when only the single-circle segment is connected to the joint segment and when the connection segment is connected. Therefore, it is possible to prevent the underground water from entering the inner side of the tunnel before and after the connection tunnel is connected.

  According to the tunnel connection structure and the tunnel connection method of the present invention, the bending moment at the joint position of the connection part between tunnels can be reduced with a simple and low-cost structure.

It is tunnel sectional drawing which shows the construction state of the large section tunnel using the tunnel connection structure by embodiment of this invention. It is the figure seen from the tunnel inner side in the figure explaining a joining segment and the 2nd single circle segment. It is the sectional view on the AA line of FIG. It is the perspective view which looked at the 2nd single circle segment connected with a joined segment from the joined segment side. It is the perspective view which looked at the connection segment connected with a joining segment from the joining segment side. It is a figure explaining a joining segment. It is the perspective view which looked at the joining segment from the diagonal 2nd joining end face side. It is a perspective view of a tunnel connection structure, and is a figure explaining the connection of a joining segment and a connection segment. It is the enlarged view of the tunnel connection structure shown in FIG. 1, (a) is the figure which looked at the 2nd single circle main girder of the 2nd single circle segment from the near side rather than the connection main girder of a connection segment, (b) is It is the figure which looked at the connection main beam from the near side rather than the 2nd single circle main beam. It is the perspective view which looked at the joining segment in the state where the connection main girder and the 2nd single circle main girder were connected from the 2nd joined end face side. It is the figure which looked at a part by the side of the 2nd junction end face of a junction segment from the tunnel inner space side. It is the BB sectional drawing of FIG. It is CC sectional view taken on the line of FIG. It is tunnel sectional drawing which shows the construction state by the tunnel connection method using a tunnel connection structure. It is tunnel sectional drawing which shows the construction state by the tunnel connection method following FIG. It is a figure which shows the state by which the connection segment was joined to the joining segment, and the 2nd single circle segment was removed from the joining segment. It is a completed drawing of the large section tunnel constructed by the tunnel connection method. It is a figure of the tunnel connection structure by a modification, Comprising: It is a figure corresponding to Fig.9 (a). It is tunnel sectional drawing which shows the conventional tunnel connection structure.

Hereinafter, a tunnel connection structure and a tunnel connection method according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the tunnel connection structure according to the present embodiment is adopted when a large cross-section underground space such as a branch junction of a road tunnel is constructed, and is constructed in parallel by a shield method in advance 2 This is applied when the widened tunnel portion 20 is constructed downstream between the single circular tunnels 10 (10A, 10B), and the large-section tunnel 1 having a substantially elliptical shape as a whole is constructed. The outer shell of the large-section tunnel 1 (tunnel different from the single-circular tunnel) has a shape surrounding the outside of the two single-circular tunnels 10A and 10B. In addition, the widening tunnel part 20 has shown the area | region 20A except the two single circular tunnels 10A and 10B among those inside the large section tunnel 1, and those inside.

The single-circular tunnel 10 is a shield tunnel constructed by a shield construction method in which a circular tunnel wall is formed using a segment by excavating with a shield excavator (not shown).
Here, as the shield excavator, for example, a machine having a known mechanism including a cutter, a propulsion jack, a skin plate, etc., is employed by excavating the face face in a sealed manner.
Here, the tunnel cross-sectional view of FIG. 1 is a view of the starting side from the face side in the tunnel axis direction, and is a state in the middle of construction of the large cross-sectional tunnel 1.

In FIG. 1, one side located on the left side of the page is a first single-circular tunnel 10A, and the other side located on the right side is a second single-circular tunnel 10B.
Further, in the large-section tunnel 1, the single-circular tunnel 10, and the widening tunnel portion 20 shown in FIG. 1, the direction orthogonal to the paper surface is defined as the tunnel axis direction, and the direction that circulates around an axis parallel to the tunnel axis direction is defined as the tunnel circumferential direction. To do. In the large-section tunnel 1 shown in FIG.

  The single circular tunnels 10A and 10B are constructed by segments extending in a circular tube shape on the natural ground G, and are provided substantially parallel to each other with a predetermined distance therebetween (see FIG. 14). The spacing between the single-circular tunnels 10A and 10B is not limited to being constant along the tunnel axis direction, and may be arbitrarily changed according to the construction conditions. The single circular tunnels 10A and 10B are each constructed with a circular cross section, and when the large cross section tunnel 1 is completed, a segment of a portion where the single circular tunnels 10A and 10B face each other (second single circular segment 12 described later). Is disassembled, and a part of segments (first single-circle segment 11 described later) that forms a substantially elliptical outer shell of the large-section tunnel 1 is left as a permanent structure.

  The segments constituting the single-circle tunnels 10A and 10B constitute a plurality of first single-circle segments 11 constituting a part of the outer shell of the large-section tunnel 1 and a portion removed when the large-section tunnel 1 is constructed. A plurality of second single-circle segments 12 and a junction segment 30 that is inserted into at least a part of the single-circle segments 11 and 12 in the tunnel circumferential direction and connected to the connection segment 21 in the outer shell of the large-section tunnel 1. And consist of That is, the single circle tunnel 10 is joined in the circumferential direction of the tunnel by a plurality of first single circle segments 11, a plurality of second single circle segments 12, and a joining segment 30 so as to have a circular cross section.

  The joining segment 30 is provided by being inserted in two places between the first single-circle segment 11 and the second single-circle segment 12, and the center line C1 (in the tunnel width direction) of the single-circle tunnels 10A and 10B in a cross-sectional view. It is located on the outside of the vertical center axis passing through the center of W) and at an angle of approximately 45 degrees (for example, 45 degrees ± 5 degrees) with respect to the horizontal center line C2. More specifically, the second joining end face 32 of the joining segment 30 is at a position where the distance L1 from the center line C1 is 30 degrees in the tunnel circumferential direction. Therefore, the proportion of the single-circular tunnel 10 in the circumferential direction of the tunnel is about １ ／ of the first single-circle segment 11 and the second single-circle segment 12 in the present embodiment. In the above description, the joining segment 30 is set at a substantially oblique 45 degree position. However, the position is not limited to this. For example, the joining segment 30 can be set within a substantially oblique 30 degree to 60 degree range.

The first single-circle segment 11 has an arc plate-like frame body formed of a steel material covering the four corners of the outer peripheral surface on the natural ground side and the inner peripheral surface on the inner air side, and a cylindrical shape on the outer peripheral surface of the arc plate-like frame member A synthetic segment is used that is roughly composed of a skin plate that is curved and welded to a peripheral surface shape, and concrete that is placed inside the arcuate plate frame. And it arrange | positions at each of a pair of single circle tunnel 10A, 10B so that it may be located in the right-and-left both sides of the outer shell of the large cross-section tunnel 1. FIG. Junction segments 30 are joined to both ends in the tunnel circumferential direction of the portion where the first single-circle segment 11 is disposed in the single-circle tunnel 10.
In addition, the 1st single circle segment 11 is provided with the bolt box for bolt joining in the steel materials which cover four side surfaces, and with respect to the segment adjacent to a tunnel circumferential direction and a ring direction using this bolt box. Joined by bolt fastening.

  Subsequently, the second single circle segment 12 will be described. Among the second single circle segments, as shown in FIGS. 2 and 3, the second single circle segment 12 connected to the joining segment 30 is changed to the second single circle segment. (Joint single circle segment) 12A, the second single circle segment 12 adjacent to the side connected to the joint segment 30 of the second single circle segment 12A is adjacent to the second single circle segment (adjacent single segment). The second single circle segment 12 other than the second single circle segment 12A and the second single circle segment 12B will be described as a second single circle segment 12C (see FIG. 2).

  As shown in FIGS. 2 and 3, the second single-circle segment 12A includes a pair of first single-circle main girders 13A extending along the circumferential direction of the tunnel and disposed at both ends in the tunnel axis direction, and the tunnel A second single circle main girder 13B extending along the circumferential direction and arranged between the pair of first single circle main girders 13A, and the outer circumferences of the first single circle main girder 13A and the second single circle main girder 13B A skin plate 14 that is curved and welded to the surface of the cylindrical circumferential surface, a first connection plate 15A that is connected to an end of the first single circular main girder 13A in the tunnel circumferential direction, and a second single plate. The steel segment provided with the 2nd connection board 15B each connected and provided in the edge part of the tunnel circumferential direction of the circle main girder 13B is used.

The pair of first single circle main beam 13A and second single circle main beam 13B are connected to the second bonding end surface 32 of the bonding segment 30 via the first connection plate 15A and the second connection plate 15B, and are connected to the bonding segment 30. When connecting segments 21A and 21B (see FIG. 1) to be described later are connected, the first single circular main beam 13A is configured to be removed from the second joining end face 32 of the joining segment 30 together with the first connecting plate 15A. Yes.
For this reason, at least the second connection plate 15B is welded to the skin plate 14, but the first connection plate 15A may not be welded to the skin plate 14 or the second connection plate 15B, and the first connection plate 15A. Between the first connection plate 15B and the second connection plate 15B, between the first connection plate 15A and the skin plate 14, a swellable sealing material for water stoppage is packed.
When the connection segments 21A and 21B are connected to the joint segment 30, only the second single circular main beam 13B is connected to the second joint end face 32 of the joint segment 30 via the second connection plate 15B.
At this time, the second single-circular main girder 13B is acted on by a larger cross-sectional force (for example, earth pressure from the natural ground side) than when the first single-circular main girder 13A is connected to the joining segment 30. Bending moment and axial force in the tunnel circumferential direction).

For this reason, it is preferable that the second single circle main girder 13B has a higher strength against the cross-sectional force acting than the first single circle main girder 13A. In particular, this strength is twice or more the strength of the first single circle main girder 13A. It is preferable that
In order to make the strength of the second single circle main beam 13B larger than the strength of the first single circle main beam 13A, for example, the thickness dimension of the second single circle main beam 13B in the tunnel axis direction is changed to the first single circle. It is preferable that the thickness of the main girder 13A is larger than the thickness dimension in the tunnel axis direction, or a rib is provided on the second single-circular main girder 13B.

In the present embodiment, first to third stiffeners 161, 162A, 162B are provided on the second single-circle segment 12A.
The 1st stiffener 161 is comprised with the steel plate provided between the 1st single circle main beam 13A and the 2nd single circle main beam 13B so that the surface may face a tunnel circumferential direction.
The first stiffener 161 has one end in the tunnel axis direction connected to the first single circle main beam 13A and the other end connected to the second single circle main beam 13B. Further, the end of the natural mountain side is connected to the skin plate 14.

The first stiffener 161 is between the first single circle main beam 13A and the second single circle main beam 13B of the pair of first single circle main beams 13A, and the other first single circle main beam 13A. A plurality of gaps are provided between the second single circle main beam 13B at predetermined intervals in the tunnel circumferential direction. In addition, the number of the stiffeners 161, 162A, 162B provided may be set arbitrarily.
In this way, by providing a plurality of first stiffeners 161 at a predetermined interval in the circumferential direction of the tunnel, shear buckling of the first single circle main beam 13A and the second single circle main beam 13B is prevented. doing.
The first stiffener 161 also plays a role of transmitting a jack thrust acting in the tunnel axis direction when the single-circular tunnels 10A and 10B are constructed.

The second stiffener 162A protrudes from the opposing surfaces of the pair of first single circular main beams 13A, extends in the circumferential direction of the tunnel, and is provided so that the surface faces the tunnel radial direction. It is composed of a steel plate. In the present embodiment, the surface of the second stiffener 162A is substantially parallel to the skin plate 14.
Further, the second stiffener 162A is connected to the first connecting plate 15A at the end in the tunnel circumferential direction.
The third stiffener 162B is a long steel plate that protrudes from both sides of the pair of second single circular main beams 13B, extends in the tunnel circumferential direction, and is provided so that the surface faces the tunnel radial direction. It is configured. In the present embodiment, the surface of the third stiffener 162B is substantially parallel to the skin plate 14.
Further, the third stiffener 162B is connected to the second connection plate 15B at the end in the tunnel circumferential direction.

  The second stiffener 162A and the third stiffener 162B are installed in the compressive force region of the second single-circle segment 12A when earth pressure is generated from the natural ground, and the first single-circle main Local buckling of the girder 13A and the second single circle main girder 13B is prevented.

  Further, as shown in FIG. 4, the first connecting plate 15A and the second connecting plate 15B are respectively provided with the first single circular seal groove 171A and the second single circular at the same tunnel radius position and continuously in the tunnel axis direction. A seal groove 171B is formed, and a first single circle seal material 172A and a second single circle seal material 172B are provided continuously along the first single circle seal groove 171A and the second single circle seal groove 171B, respectively. It has been. The first single circular seal groove 171A and the first single circular seal material 172A constitute the first single circular seal structure 173A, and the second single circular seal groove 171B and the second single circular seal material 172B are the second single circular seal. The structure 173B is configured.

Returning to FIG. 2, the second single-circle segment 12B and the second single-circle segment 12C include a pair of single-circular main girders 13C extending along the circumferential direction of the tunnel and arranged at both ends in the tunnel axis direction, A skin plate 14 that is curved and welded to the outer circumferential surface of the single-circular main girder 13C and welded to the outer peripheral surface of the single-circular main girder 13C, and a joint provided so as to connect ends of the pair of single-circular main girders 13C in the tunnel circumferential direction A steel segment with a plate 18 is used.
In this embodiment, a pair of single circle main girders 13C is provided at both ends in the tunnel axis direction, but the number of single circle main girders 13C may be arbitrarily set.

Further, as shown in FIGS. 2 and 3, the second single circle segment 12B is provided with an end plate 191 facing the joint plate 18 at an intermediate portion in the tunnel circumferential direction, and is connected to the second single circle segment 12A. A stiffening plate 192 (stiffening material) for connecting the joint plate 18 and the end plate 191 is provided. The stiffening plate 192 is arranged with the surface direction substantially parallel to the skin plate 14 of the second single-circle segment 12B.
As described above, the end plate 191 and the stiffening plate 192 are provided in the second single-circle segment 12B, whereby the axial force in the tunnel circumferential direction can be satisfactorily transmitted. The stiffening plate 192 is not limited to steel, and may be made of concrete or steel / concrete. Furthermore, a structure in which the space surrounded by the stiffening plate 192, the end plate 191 and the skin plate 14 is filled with concrete may be used.
Further, the end plate 191 may be provided on the second single circle segment 12A side with respect to the intermediate portion in the tunnel circumferential direction of the second single circle segment 12B.
In addition, one or both of a stiffening plate 192 and an end plate 191 may be provided in the second single-circle segment 12B.

Moreover, it is preferable that a plurality of vertical ribs (not shown) are provided between the pair of single circle main beams 13C of the second single circle segment 12C so that the surfaces thereof face the tunnel circumferential direction. . These vertical ribs are made of steel plates, and both ends in the tunnel axis direction are connected to the single circular main girder 13C, respectively, and the ends on the natural ground side are connected to the skin plate 14.
These vertical ribs prevent shear buckling of the single-circular main girder 13C and also play a role of transmitting jack thrust acting in the tunnel axis direction when constructing the single-circular tunnels 10A and 10B.

  When the first single-circle segment 11, the second single-circle segments 12A to 12C, and the joining segment 30 are formed to have substantially the same width dimension (dimension in the tunnel axis direction) and are connected to each other, each tunnel circumferential direction Are connected so that their axes coincide.

Here, before describing the specific configuration of the joining segment 30, the widened tunnel portion 20 will be described.
The widened tunnel portion 20 shown in FIG. 1 is curved with a constant thickness in the shape of a flat circular arc plate connected to the upper side and the lower side of the single circular tunnels 10A, 10B outside the two single circular tunnels 10A, 10B. A region 20A between the upper connection segment 21A and the lower connection segment 21B in a state in which the arch-shaped connection segment 21 (21A, 21B) is provided. The natural ground G1 in this region 20A is excavated by using an excavator such as an excavator after the upper and lower connection segments 21A and 21B are connected to the single circular tunnels 10A and 10B, respectively.

Each of the connection segments 21A and 21B connected to the joint segment 30 is divided into a plurality along the circumferential direction of the tunnel. As shown in FIG. 5, the connection segments 21A and 21B connected to the junction segment 30 among the divided connection segments 21A and 21B are provided at both ends in the tunnel axis direction and along the tunnel circumferential direction. A pair of connecting main girders 22 extended, a skin plate 23 curved and welded to the outer circumferential surface of the pair of connecting main girders 22 in a flat circumferential shape, and ends of the connecting main girders 22 in the tunnel circumferential direction A connection seal formed by a connection plate 24 provided on the connection plate 25, a connection seal groove 25A provided continuously in the tunnel axis direction, and a connection seal member 25B provided continuously along the connection seal groove 25A. A steel segment with a structure 25 is used.
Such connection segments 21A and 21B are formed to have the same width dimension (dimension in the tunnel axis direction) as the segment of the single-circular tunnel 10 (the first single-circular segment 11, the second single-circular segments 12A to 12C, and the joining segment 30). In addition, when connected to the joining segment 30, the joining segment 30 is connected so that the axis in the circumferential direction of the tunnel coincides.

  Further, the skin plate 23 provided in the connection segments 21A and 21B connected to the joining segment 30 is made thicker than the skin plate provided in other connection segments, or a reinforcing material is provided. It is desirable to be reinforced. This is because the vertical ribs (not shown) passing in the tunnel axis direction cannot be provided in the range where the connecting main girder 22 and the second single-circular main girder 13B overlap, and therefore the strength of the skin plate compared to other segments. This is because there is a shortage.

  As shown in FIG. 1, the connection segments 21 </ b> A and 21 </ b> B are arranged at the top end portion and the lower plate portion of the outer shell that forms an elliptical shape of the large-section tunnel 1. That is, the upper connection segment 21A is disposed with the protruding surface facing upward, and the lower connection segment 21B is disposed with the protruding surface facing downward.

  As shown in FIGS. 6 and 7, the joining segment 30 includes a frame 33 formed of a steel material covering four corners of the outer peripheral surface on the natural ground side and the inner peripheral surface on the inner space side, and the outer peripheral surface of the frame 33. And a skin plate 34 that is curved and welded to the shape of a cylindrical peripheral surface, and a steel segment that is roughly configured. As shown in FIG. 1, the joint segment 30 is interposed between the first single circle segment 11 and the second single circle segment 12 </ b> A, and a first single circle segment at a first joint end face 31 at one end in the tunnel circumferential direction. 11 is connected to the joint surface 11a of the eleventh, and the joint surface 12a of the second single-circle segment 12A and the joint surface 21a of the connection segment 21 (see FIG. 5) can be simultaneously connected by the second joint end surface 32 at the other end. It has become.

  Here, FIG. 8 shows the joint structure of the first single-circle segment 11, the joint segment 30, and the connection segment 21 of the single-circle tunnel 10, and the second single-circle segments 12A to 12C are removed (see FIG. 8). 13). As shown in FIG. 8, the segment pitch of the segment of the single-circular tunnel 10 and the segment pitch of the connection segment 21 coincide with the tunnel axis direction.

As shown in FIGS. 7 and 9A and 9B, the joining segment 30 has the first joining end face 31 and the second joining end face 32 as described above, and the lower part of the second joining end face 32. A convex portion 35 that protrudes outward from the outer circumferential direction of the tunnel is provided. The connection segment 21 is in contact with the outer peripheral surface 35 a on the natural mountain side of the convex portion 35.
The first joint end face 31 is provided with a bolt box (not shown) that can be bolted to the joint surface of the first single-circle segment 11.

When the single-circular tunnels 10A and 10B (see FIG. 1) are constructed, as shown in FIG. 2, the first joint of the second single-circular segment 12A is formed at both ends in the tunnel axis direction, as shown in FIG. The single circle main beam 13A is connected, and the second single circle main beam 13B of the second single circle segment 12A is connected to the center portion in the tunnel axis direction.
And when the connection segment 21 is connected to the joining segment 30, as shown in FIG. 9 (a), (b) and FIG. 10, the 2nd single-circle segment 12A connected to the 2nd joining end surface 32 is shown. The two connecting main girders 22 of the connecting segment 21 are respectively connected to the positions where the single single-yield main girders 13A are removed and the first single-yen main girders 13A are connected.

Therefore, as shown in FIG. 7, the first main girder joint is provided with the bolt holes 32 a for the first single-circular main girder 13 </ b> A and the connecting main girder 22 at both ends in the tunnel axis direction, as shown in FIG. 7. A portion 32A is provided, and a second main girder joint 32B in which a bolt hole 32a for the second single-circular main girder 13B is provided in an intermediate portion in the tunnel axis direction. The first main girder joint 32A is provided at a position corresponding to the first single-circle main girder 13A and the connecting main girder 22, and the second main girder joint 32B is connected to the second single-circle main girder 13B. It is provided at the corresponding position.
Accordingly, the first single-circle main beam 13A, the second single-circle main beam 13B, and the connection main beam 22 are detachably connected to the second joint end surface 32 by the bolts. In FIG. 10, the skin plate 23 of the connection segment 21 and the skin plate 14 of the second single-circle segment 12A are omitted for easy viewing.

Further, as shown in FIGS. 11 to 13, the joining segment 30 is provided with an end plate 36 (see FIGS. 11 and 13) facing the second joining end face 32 in the middle portion in the tunnel circumferential direction. A stiffening plate 37 (stiffening material) that connects the joining plate constituting the second joining end face 32 and the end plate 36 is provided. The stiffening plate 37 is arranged so that the surface direction is substantially parallel to the skin plate 34 of the joining segment 30.
Further, by setting the position of the stiffening plate 37 in the tunnel radial direction as the position of the region where the connection main girder 22 of the connection segment 21 is installed, the axial force in the tunnel circumferential direction can be satisfactorily transmitted. The stiffening plate 37 is not limited to steel but may be made of concrete or steel / concrete. Furthermore, a structure in which concrete is filled in a space surrounded by the stiffening plate 37, the end plate 36, and the skin plate 34 may be employed.

Further, as shown in FIG. 13, a joining seal groove 38A provided continuously in the tunnel axis direction and a joining provided continuously along the joining seal groove 38A on the second joining end face 32 of the joining segment 30. And a third seal structure 38 constituted by the seal material 38B.
The joining sealing material 38B, the second single-circular sealing material 172B (see FIG. 4), and the connection sealing material 25B are in the same tunnel radial direction position in the connection state between the segments and close to the outer periphery of the segment. It is arranged at the position.

Next, the tunnel connection method using the above-described tunnel connection structure and the operation of the tunnel connection structure will be described in detail based on the drawings.
Here, as shown in FIG. 1, two single-circular tunnels 10A and 10B constructed in advance by the shield method are constructed, and the widened tunnel portion 20 of the large-section tunnel 1 is formed on the single-circular segment. A construction method for connecting the connection segments 21 will be described.

As shown in FIG. 14, first, two single circular tunnels 10A and 10B are constructed in advance.
Each of these single-circular tunnels 10A and 10B adopts a normal shield method, and is excavated from a start shaft such as a vertical shaft by a shield excavator having a predetermined outer diameter, and at the same time as the excavation, a single circular segment is formed within the shield of the excavator body. 11 and 12 are assembled and constructed as a shield tunnel.

  At this time, the joining segments 30 are inserted at the two locations described above in the tunnel circumferential direction of the single-circular tunnel 10, and as shown in FIGS. 2, 3, and 10, The first single-girder main girder 13A of the second single-circle segment 12A is connected to the first main girder joint 32A by a bolt, and the second single-girder main girder 13B is connected to the second main girder joint 32B by a bolt. A single circular tunnel 10 is constructed. The two single-circular tunnels 10A and 10B may be dug simultaneously in parallel, or may be dug with either one of the tunnels preceding.

  At this time, in the constructed single-circular tunnel 10, the second single-circular segment 12A connected to the joining segment 30 is a segment having the skin plate 14 as shown in FIG. Compared with a segment having a complicated structure provided with a portion, the structure is simple, and an excessive bending moment such as a segment having a notch is not applied.

  At this time, the single-circular tunnel 10 has a structure without a notch in which the position of the outer peripheral surface of the tunnel on the ground mountain side coincides, and the outer peripheral surface of the individual single-circle segments 11 and 12 connected in the tunnel peripheral direction is the entire periphery. Therefore, it is possible to more surely realize a structure in which an excessive bending moment does not act.

Next, as shown in FIGS. 15 and 1, the connection segments 21 (21 </ b> A, 21 </ b> B) are connected to the joining segments 30 disposed at the upper and lower portions of each of the single circular tunnels 10 </ b> A, 10 </ b> B.
Specifically, first, after constructing adjacent single-circle tunnels 10A and 10B, a natural ground improving agent from the inner space side of each single-circular tunnel 10A and 10B toward the surrounding natural ground in the installation area of the connection segment 21. The ground is improved by injecting a chemical solution such as liquid nitrogen or the like, and excavating the ground in an appropriate area for installing the connection segment 21.

Subsequently, the first single circle main girder 13A, the first connection plate 15A, and the skin plate 14 of the second single circle segment 12A connected to the joint segments 30 of the existing single circle tunnels 10A and 10B are removed. In the present embodiment, since the first stiffener 161 (see FIG. 2) is connected to the first single circle main beam 13A and the second single circle main beam 13B, the first single circle main beam 13A is When removing, the first stiffener 161 and the first single-circle main beam 13A are fused.
As a result, the second single circle main girder 13B of the second single circle segment 12A is connected to the joint segment 30 via the second connection plate 15B.
Further, by removing the first single-circle main girder 13A, the first connecting plate 15A, and the skin plate 14, the first main girder joint 32A (see FIG. 7) of the second joint end surface 32 of the joint segment 30 is obtained. It will be exposed and will be in the state which can work from the outer side of the single circle tunnel 10 (refer FIG. 1) with respect to 32 A of 1st main beam joint parts.

Subsequently, as shown in FIG. 10, the pair of connecting main girders 22 of the connection segment 21 is arranged at the position where the pair of first single circle main girders 13A of the second single circle segment 12A is joined, respectively. The connection plate 24 of the girder 22 is bolted to the first main girder joint 32A. As a result, the connection main girder 22 is connected to the second joint end face 32 without interfering with the second single circular main girder 13B, and the outer shell portion of the large-section tunnel 1 having an elliptical cross section is constructed. .
At this time, the position of the junction segment 30 and the connection segment 21 in the tunnel axis direction are the same.

  As described above, when the first single circle main beam 13A, the first connection plate 15A, and the skin plate 14 of the second single circle segment 12 connected to the second bonding end surface 32 of the bonding segment 30 are not removed, Only the single-circle segments 11 and 12 and the junction segment 30 can function as a tunnel. And only before connecting the joining segment 30 to the second joining end face 32, the second joining end face of the connecting main girder 22 is obtained by removing the first single-circular main girder 13A, the first connecting plate 15A, and the skin plate 14. The connection main girder 22 is connected to the first single circle main girder 13A, the second single circle main girder 13B and the skin plate 14 of the second single circle segment 12 without interference. be able to.

  Moreover, even after the connection segment 21 is connected to the joint segment 30, the skin plates 23 and 34 located on the outer peripheral surface of the tunnel of the joint segment 30 and the connection segment 21 are connected to each other in the tunnel circumferential direction. Since no gap is formed between 23 and 34, it becomes possible to prevent the underground water from entering the inside of the tunnel.

  In the present embodiment, since the second single circle main beam 13B is connected to the second bonding end surface 32 between the pair of connection main beams 22 connected to the second bonding end surface 32, the second single circle main The girder 13B and the connecting main girder 22 are arranged with good balance in the tunnel axis direction, and the stability of the bending moment can be enhanced.

Further, before connecting the connection segment 21 to the second joint end face 32 of the joint segment 30, a first single circle sealing material provided between the second single circle segment 12 </ b> A and the second joint end face 32 of the joint segment 30. 172A and the second single-circle sealing material 172B and the joining sealing material 38B are continuously in contact with each other in the tunnel axial direction at the same tunnel radial direction position.
Further, after the connection segment 21 is connected to the second joining end surface 32, the connection sealing material 25B provided on the end surface of the connection segment 21 inserted instead of the removed first connection plate 15A is left. The second single circular sealing material 172B provided in the second connection plate 15B is continuous in the tunnel axial direction, and the second single circular sealing material 172B, the connection sealing material 25B, and the bonding sealing material 38B have the same tunnel radius. In the direction position, the abutting is continuously made in the tunnel axis direction.
Therefore, it becomes possible to prevent the groundwater from entering the tunnel in the sky before and after connection of the widening tunnel.

Next, as shown in FIG. 1, after connecting the upper and lower connection segments 21A, 21B to the single-circular tunnels 10A, 10B, the widened tunnel portion 20 is connected to the second connection segments 21 and the second single-circular tunnels 10A, 10B. The natural ground G1 in the region 20A between the single circle segment 12 is excavated. At this time, since the connection segment 21 is connected to the second joining end face 32 of the joining segment 30, after securing the stability of the surrounding natural ground of the joining portion, the joining segment 30 existing inside the large-section tunnel 1 The 2nd single circle segment 12 except the 2nd connection board 15B connected is removed and removed. At this time, the second single circle main beam 13B and the second connection plate 15B are fused.
As a result, as shown in FIG. 16, only the connection segments 21A and 21B are connected to the joining segment 30, and as shown in FIG. 17, the first single-circle segment 11 remaining in the natural ground without being removed. A large space underground space (large-section tunnel 1) in which an outer shell is formed by the connecting segments 21A and 21B.

  As described above, in the present embodiment, as shown in FIG. 1, the second single circular segment 12 </ b> A of the single circular tunnels 10 </ b> A and 10 </ b> B and the connection segments 21 </ b> A and 21 </ b> B of the widened tunnel portion 20 are formed on the second joint end surface 32 of the joint segment 30. And the second single circle main beam 13B and the connection main beam 22 can be connected at the same time without interfering with each other. Therefore, the connection segments 21 </ b> A and 21 </ b> B can be connected to a part of the first single circle segment 11 via the junction segment 30 while the two single circle tunnels 10 </ b> A and 10 </ b> B are stabilized.

  In this embodiment, since the stiffening plate 37 that connects the joining plate constituting the second joining end face 32 and the end plate 36 is provided, the stiffening plate 37 is a deformation of the second joining end face 32 itself. As a matter of course, the axial force in the tunnel circumferential direction by the connecting segment 21 and the second single-circular segment 12 can be transmitted through the end plate 36 from the stiffening plate 37 provided on the joining plate of the joining segment 30. There is an advantage that the circular tunnel 10 can be efficiently transmitted in the circumferential direction of the tunnel.

  In the present embodiment, each of the first single circle main beam 13A, the second single circle main beam 13B, and the connection main beam 22 has a first connection having a bolt hole at an end connected to the second joint end surface 32. Since the plate 15A, the second connection plate 15B, and the connection plate 24 are provided, the first single circle main beam 13A, the second single circle main beam 13B, and the connection main beam 22 are bolted to the second bonding end surface 32. Thus, it can be attached and connected easily and in a short time, so that construction can be performed efficiently.

In addition, after connecting the connection segment 21 to the second joint end surface 32 of the joint segment 30, the connection segment 21 faces the outer peripheral surface side of the convex portion 35 projecting outward from the lower portion of the second joint end surface 32 in the tunnel circumferential direction. In order to quickly remove the second single circular main girder 13B connected to the second joint end face 32 at the site, the second joint end face 32 is installed with the direction inclined from the tunnel normal direction, and the second joint end face It is good to install in the shape where the wedge shape between 32 and the outer peripheral surface 35a by the side of the natural mountain of the convex part 35 becomes still larger. Specifically, the second joining end face 32 is inclined and installed so as to gradually approach the end plate 36 of the joining segment 30 from the inner space side to the natural ground side.
In this way, even when the connection segment 21 is installed on site, it is easy to align the second joining end face 32, which is convenient.
Further, since the axial compression force acts on the tunnel installed in the tunnel circumferential direction due to the external pressure, resistance is generated when a part of the tunnel is removed and the work becomes difficult. Therefore, the surface of the connecting plate facing the second joining end surface 32 is preliminarily provided with a face material (for example, a fluororesin plate) that is easily slipped, so that the second single circular main beam 13B can be removed more easily.

  Furthermore, in the present embodiment, as shown in FIGS. 3 and 6, a convex portion 35 is formed on the lower portion of the second joint end surface 32 of the joint segment 30, and the convex portion 35 is formed on the outer peripheral surface 35 a on the ground mountain side. Since the inner side of the tunnel of the second single-circle main beam 13B of the two single-circle segments 12A is in contact, the junction segment 30 is positioned above the single-circle tunnels 10A and 10B, and is connected to the second junction end face 32 of the junction segment 30. When not only the second single-circle segment 12 but also the connection segment 21 is connected, the bending moment acting on the portion of the second joint end face 32 is increased, but the second unit connected to the second joint end face 32 is increased. The main circle girder 13B abuts on the outer peripheral surface 35a of the convex portion 35, and the load of the second single circular main girder 13B can be borne by the entire joining segment 30. Therefore, the bending moment acting on the second joint end face 32 can be suppressed, and the tunnel stability can be ensured.

  Furthermore, in the present embodiment, the connection position between the junction segment 30 and the connection segment 21 of the single-circular tunnel 10 is set to the position outside the tunnel in the elliptical large-section tunnel 1 so that the tunnel cross-section is greatly expanded. It becomes possible to make it a shape close to an ellipse without bending, and the bending moment generated at the joint with the joining segment 30 can be reduced.

  Although the embodiments of the tunnel connection structure and the tunnel connection method according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  For example, in the present embodiment, the present tunnel connection structure is applied when the two single circular tunnels 10A and 10B are connected to each other by the widening tunnel portion 20 to construct the elliptical large-section tunnel 1. The present invention is not limited to such an application example. For example, the present invention can be applied to a case where a widened portion formed with a connection segment is provided for one single circular tunnel 10.

  In addition, as the configuration of the segments of the single-circular tunnel 10, two types of the first single-circular segment 11 made of a synthetic segment and the second single-circular segment 12 made of a steel segment except for the joining segment 30 as in the present embodiment. However, the present invention is not limited to this, and all the segments may be steel segments all around the tunnel.

In addition, in this embodiment, the number of joint segments 30 provided is two in the tunnel circumferential direction of one single-circular tunnel 10, but it may be one.
Furthermore, as a specific configuration of the joining segment 30, the shape, thickness, attachment position, and the like of the end plate 36 and the stiffening plate 37 can be changed as appropriate, and can be omitted.

Further, the connection between the second joining end face 32 in the joining segment 30 and the first single circle main girder 13A, the second single circle main girder 13B, and the connection main girder 22 is not limited to joining by bolts and nuts. Other connection means such as one-touch type bolt joining may be employed. And the 2nd junction end surface 32 can be suitably set as a junction surface according to composition, such as each number of single circle main beam 13C and connection main beam 22, size.
Furthermore, although the convex part 35 is formed in this Embodiment as the joining segment 30, structures, such as this protrusion length, can be changed suitably and can also be abbreviate | omitted.

  Furthermore, in the present embodiment, the end plate 36 facing the second joint end face is provided at the intermediate portion of the joint segment in the tunnel circumferential direction, but the end plate 36 is limited to this position. There is no. For example, as shown in FIG. 18, the first joint end surface 31 can also serve as the end plate 36, and the length of the stiffening plate 37 in the tunnel circumferential direction can be increased.

In the present embodiment, the second single circle segment 12A connected to the joining segment 30 is provided with one second single circle main beam 13B between the pair of first single circle main beams 13A. A plurality of second single circle main girders 13B may be provided. Further, the bending moment acting by the earth pressure from the ground side of the first single circular main girder 13A and the strength against the axial force in the circumferential direction of the tunnel, and the bending moment acting by the earth pressure from the second single circular main girder 13B ground side. The strength against the axial force in the tunnel circumferential direction may be set to an optimum value.
In the present embodiment, the second single circle segment (joined single circle segment) 12A includes a pair of first single circle main girder 13A and second single circle main girder 13B, and the second single circle segment (Adjacent single circle segment) 12B and second single circle segment (second single circle segment other than joined single circle segment 12A and adjacent single circle segment 12B) 12C are the first single circle main girder 13A and the second single circle main Although it is not a structure provided with the digit 13B, it is good also as a structure provided with a pair of 1st single circle main beam 13A and 2nd single circle main beam 13B also about 2nd single circle segment 12B, 12C.
In the present embodiment, the first connection plate 15A, the second connection plate 15B of the second single-circle segment 12A, and the connection plate 24 of the connection segments 21A, 21B abut on the second joint end surface 32 of the joint segment 30. For example, it may be connected to the second joint end face 32 via a plate material between the second joint end face 32. In such a case, the plate material is preferably provided with a seal structure having a seal groove and a seal material.

1 Large section tunnel 10, 10A, 10B Single circle tunnel 11 First single circle segment 12 Second single circle segment 12A Second single circle segment (joint single circle segment)
12B 2nd single circle segment (adjacent single circle segment)
13A 1st single circle main girder 13B 2nd single circle main girder 14 Skin plate 18 Joint plate 20 Widening tunnel part 21, 21A, 21B Connection segment 22 Connection main beam 30 Joint segment 31 First joint end face 32 Second joint end face 36 End Plate 37 Stiffening plate (stiffening material)
161 First stiffener 162A Second stiffener 162B Third stiffener 191 End plate 192 Stiffener plate (stiffener)

Claims (9)

A tunnel connection structure for connecting a connection segment constituting a tunnel different from the single circle tunnel to a plurality of single circle segments constituting a single circle tunnel constructed in advance,
The plurality of single-circle segments are provided to be inserted into at least a part of the tunnel circumferential direction, the single-circle segment is connected to the first joint end face at one end in the tunnel circumferential direction, and the second joint end face at the other end A joining segment to which both the connecting segment and the single-circle segment are connected;
Of the plurality of single circle segments, at least a joint single circle segment that is directly connected to the second joint end surface includes a pair of first single circle main girders respectively disposed at both ends in the tunnel axis direction, and the pair of first circle segments. A second single circle main girder arranged between one single circle main girder,
The connection segment has a pair of connection main beams arranged at both ends in the tunnel axis direction,
The joint single circle segment is connected to the second joint end surface of the joint segment first, and then the joint single circle segment is removed and the connection segment is connected.
When the joint single circle segment is connected to the joint segment, the pair of first single circle main beams and the second single circle main beam are connected to the second joint end surface,
When the connection segment is connected to the joint segment, the pair of first single circle main girders are removed, and the pair of first single circle main girders on the second joint end surface are connected to the positions where the pair is connected. A tunnel connection structure characterized in that a pair of connection main beams are connected. The adjacent single circle segment to be bonded adjacent to the bonded single circle segment among the single circular segments is provided with a joint plate at the end on the bonded single circle segment side,
An end plate facing the joint plate is provided on the side of the joining single circle segment rather than an intermediate portion in the tunnel circumferential direction of the adjacent single circle segment,
The tunnel connection structure according to claim 1, wherein a stiffening material that connects the joint plate and the end plate is provided.   The second single circular main girder is a bending moment that acts on the earth pressure from the natural ground side and the bending moment that acts on the axial force in the tunnel circumferential direction from the natural pressure on the first single circular main girder. The tunnel connection structure according to claim 1, wherein the tunnel connection structure is greater than the strength against the axial force in the circumferential direction of the tunnel.   The second single circular main girder is a bending moment that acts on the earth pressure from the natural ground side and the bending moment that acts on the axial force in the tunnel circumferential direction from the natural pressure on the first single circular main girder. The tunnel connection structure according to claim 3, wherein the tunnel connection structure is at least twice the strength against the axial force in the tunnel circumferential direction.   The joint segment and the single-circle segment connected to the first joint end face and the second joint end face of the joint segment have the same outer peripheral surface position on the ground mountain side in the tunnel radial direction in the tunnel circumferential direction. The tunnel connection structure according to any one of claims 1 to 4, wherein the tunnel connection structure is provided. An intermediate portion in the tunnel circumferential direction of the joint segment or the first joint end face is provided with an end plate facing the second joint end face,
The tunnel connection structure according to any one of claims 1 to 5, wherein a stiffening material is provided to connect the joining plate constituting the second joining end face and the end plate. The first single circle main girder, the second single circle main girder, and the connection main girder are connected to end surfaces connected to the second joint end surfaces, respectively, and a connection plate is connected via the connection plate. 2 is connected to the joint end face,
The second joining end face of the joining segment, the connection plate connected to the first single circle main girder, and the connection plate connected to the second single circle main girder are respectively joined at the same tunnel radial direction position. A seal groove, a first single-circular seal groove, and a second single-circular seal groove are provided continuously in the tunnel axial direction, and a joining seal material, a first single-circular seal material, and a second single circle are provided along these seal grooves. A sealing material is continuously provided, and the bonding sealing material and the first single circular sealing materials, and the bonding sealing material and the second single circular sealing materials are continuously in contact with each other in the tunnel axis direction,
In the connection plate connected to the connection main beam, a connection seal groove is continuously provided at the same tunnel radial direction position as the first single-circle seal groove, and the connection seal material is continuously provided along the connection seal groove. Prepared,
The first single circle main girder and the connection plate connected to the first single circle main girder are removed from the connection segment, and the connection segment is connected to the connection segment via the connection plate connected to the connection main girder. 7. The device according to claim 1, wherein in the connected state, the second single-circular seal material and the connection seal material are continuous in the tunnel axis direction and have a seal structure in contact with the joint seal material. The tunnel connection structure according to any one of the above. A tunnel connection method using the tunnel connection structure according to any one of claims 1 to 7,
The joint segment is inserted into at least a part of the tunnel circumferential direction of the single circle segment, the single circle segment is connected to the first joint end surface of the joint segment, and the single circle segment of the single circle segment is connected to the second joint end surface. Connecting the first single circle main beam and the second single circle main beam to construct a ring-shaped single circle tunnel;
The first single circle main girder is removed from the second joint end face, and the connection main girder of the connection segment is connected to the position where the first single circle main girder of the second joint end face is connected. Connecting the connecting segment to a joining segment. The first single circle main girder, the second single circle main girder, and the connection main girder are connected to end surfaces connected to the second joint end surfaces, respectively, and a connection plate is connected via the connection plate. 2 is connected to the joint end face,
Before connecting the connection segment to the second joint end face of the joint segment, a seal provided on the second joint end face and a seal provided on a connection plate coupled to the first single-circle main girder Between the materials, and the sealing material provided on the connection plate connected to the second single-circular main girder and the sealing material provided on the second joint end face, in the tunnel axis direction continuously,
After the connection segment is connected to the second joint end face of the joint segment, the connection segment is connected to the connection main beam inserted instead of the connection plate connected to the removed first single circle main beam. A seal material provided on the connection plate and a seal material provided on the connection plate connected to the remaining second single-circular main girder in the tunnel axis direction; The connecting plate connected to the connecting plate and the connecting plate connected to the connecting main girder, and the sealing material provided to the joining segment are continuously connected in the tunnel axial direction at the same tunnel radial direction position. The tunnel connection method according to claim 8, wherein the abutting contact is made.

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