Tunnel lining structure and construction method thereof

Abstract

To provide a tunnel lining body capable of reducing the number of segments, deforming the segments compactly and easily transporting them, and improving work efficiency when assembling the segments.SOLUTION: A tunnel lining body 10 is formed into a rectangular cylindrical shape by arranging an upper segment 20 and a lower segment 30 facing each other. The upper segment 20 and the lower segment 30 include first plate-like portions 21, 31, and two second plate-like parts 22a, 22b, 32a, 32b erected on both side edges of the first plate-like parts 21, 31, respectively. The first plate-like portions 21, 31 are divided into first pieces 25, 35 and second pieces 26, 36. The first pieces 25, 35 and the second pieces 26, 36 are connected by a hinge 40 having a rotating shaft 41 extending in the tunnel axis direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a tunnel lining structure and a method for constructing a tunnel lining structure.

Background Art

[0002] In the shield method, a tunnel lining structure is constructed by continuously installing segment rings underground as the ground is excavated. A conventional segment ring connects four segments curved along the inner peripheral surface of the tunnel in the circumferential direction of the tunnel (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When constructing a rectangular shield tunnel, if the number of segments into which the segment ring is divided can be reduced to decrease the conveyance frequency of the segments and the man-hours required for assembling the segments, the construction period can be shortened. However, when the segments become larger, there is a problem that it becomes difficult to convey and change the direction of the segments in the tunnel. An object of the present invention is to solve the above-described problems, reduce the number of segments, compactly deform the segments so that they can be easily conveyed, and improve the working efficiency when assembling the segments, and to provide a tunnel lining structure and a method for constructing a tunnel lining structure.

Means for Solving the Problems

[0005] In order to solve the above problems, a first invention is a tunnel lining body provided on the inner peripheral surface of a tunnel, which is formed in a rectangular cylindrical shape by arranging two segments opposite to each other. The segment includes a first plate-shaped portion and two second plate-shaped portions respectively erected on both side edges of the first plate-shaped portion, and end faces of the second plate-shaped portions of both segments are connected to each other. The first plate-shaped portion is divided into a first piece on one second plate-shaped portion side and a second piece on the other second plate-shaped portion side, and the first piece and the second piece are connected by a hinge having a rotation axis extending in the tunnel axis direction. In the tunnel lining body of the present invention, by reducing the number of segments and folding the segments by the hinge of the first plate-shaped portion to deform them compactly, the segments can be easily transported in the tunnel. Thereby, the working efficiency when assembling the segments can be improved, so that the construction period of the shield method can be shortened. Further, in the tunnel lining body of the present invention, with one of the first piece and the second piece positioned in the tunnel, by opening the first piece and the second piece, the other of the first piece and the second piece can also be positioned in the tunnel. Further, in the tunnel lining body of the present invention, the hinge bears the tensile force generated between the first piece and the second piece, so that the strength of the connecting portion between the first piece and the second piece can be increased. In the above-described tunnel lining body, when the first piece and the second piece are folded at the hinge to deform the segment into a rectangular cylindrical shape for transportation and installation, it becomes easier to take the center of gravity of the segment and the segment becomes stable, so that the work becomes easier.

[0006] In the above-described tunnel lining body, it is preferable to attach the hinge to the inner surfaces of the first piece and the second piece. In this configuration, when positive bending occurs inward at the connecting portion between the first piece and the second piece, the moment arm length becomes larger than when the hinge is attached to the outer surfaces of the first piece and the second piece. Therefore, the strength of the connecting portion between the first piece and the second piece can be increased. In the above-described tunnel lining body, it is preferable to provide a connecting member at the connecting portion between the first piece and the second piece, and insert the connecting member into the hole portion of the first piece and also into the hole portion of the second piece, thereby increasing the strength of the connecting portion between the first piece and the second piece. Note that, for example, a bolt joint or a pin joint can be used for the connection between the connecting member and the first piece and the second piece. In the above-described tunnel lining body, it is preferable to incline the end face of the second plate-shaped portion of one of the segments such that the inner edge portion is positioned below the outer edge portion, and also incline the end face of the second plate-shaped portion of the other segment such that the inner edge portion is positioned below the outer edge portion. In this configuration, after first installing one of the segments in the tunnel, the other segment is carried into the tunnel in a folded state. When the other segment is opened, the end face of the second plate-shaped portion of the other segment can be easily overlapped with the end face of the second plate-shaped portion of the one segment. In the above-described tunnel lining body, it is preferable to connect the first piece and the second piece via a waterstop material to enhance the waterstop performance of the segment.

[0007] To solve the above problems, a second invention is a method for constructing a tunnel lining body. First, the first piece and the second piece are folded to prepare the two segments in a state where each is deformed into a cylindrical shape. Subsequently, in the first assembly step, in one of the segments, the first piece and the second piece are opened to deform the first plate-shaped portion into a flat shape. Then, in the second assembly step, in the other segment, the first piece and the second piece are opened to deform the first plate-shaped portion into a flat shape, and the end faces of the second plate-shaped portions of the two segments are connected to each other. In the construction method of the tunnel lining structure of the present invention, by using the above-described tunnel lining structure, the work efficiency when assembling the segments can be improved, so that the construction period of the shield method can be shortened. In the construction method of the above-described tunnel lining structure, when the claw portion of the forklift is inserted into the segment folded in a tubular shape and the segment is transported by the forklift, the work efficiency can be increased. In the construction method of the above-described tunnel lining structure, the ground where ground improvement has been performed is excavated by an open shield machine, and the first assembly step and the second assembly step can be performed behind the open shield machine.

Effect of the Invention

[0008] In the tunnel lining structure and the construction method of the tunnel lining structure of the present invention, the number of segments can be reduced and they can be easily transported, and the man-hours for assembling the segments can be reduced, so that the construction period of the shield method can be shortened.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a side view showing a tunnel lining body according to an embodiment of the present invention. In the present embodiment, as shown in FIG. 1, a tunnel lining body 10 in a rectangular shield tunnel 2 (hereinafter simply referred to as "rectangular tunnel 2") and a construction method of the tunnel lining body 10 will be described. As shown in FIG. 1, when constructing a tunnel below an underground structure 3 such as a subway or a road, it is necessary to remove a part of the earth retaining walls 5, 5 used when constructing the underground structure 3. Therefore, after improving the ground around the underground structure 3, a rectangular tunnel 2 is constructed by an open shield machine 4, and an operator cuts the earth retaining wall 5 from inside the rectangular tunnel 2. At this time, a tunnel lining body 10 is constructed in the rectangular tunnel 2 behind the open shield machine 4. FIG. 2 is a front view showing a tunnel lining body according to an embodiment of the present invention. The tunnel lining body 10 of the present embodiment includes an upper segment 20 and a lower segment 30 as shown in FIG. 2. By arranging the upper segment 20 and the lower segment 30 to face each other vertically, it is formed in a rectangular tubular shape.

[0011] FIG. 5 is a front view showing a state where the lower segment is opened in the construction method of the tunnel lining body according to the embodiment of the present invention. As shown in FIG. 5, the lower segment 30 includes a first plate-like portion 31 and two left and right second plate-like portions 32a and 32b erected on the left and right side edges of the first plate-like portion 31, respectively. The lower segment 30 is formed in a U-shaped that opens upward. The first plate-like portion 31 is a plate-like member made of steel and includes a skin plate covering the bottom surface of the rectangular tunnel 2, main girders arranged in the tunnel circumferential direction, vertical ribs and joint plates arranged in the tunnel axial direction, and the like. The length of the first plate-like portion 31 in the left-right direction is formed to be the same as the length of the bottom surface of the rectangular tunnel 2 in the left-right direction. The first plate-like portion 31 is divided into a left first piece 35 and a right second piece 36. In the lower segment 30, the length of the second piece 36 in the left-right direction is formed to be larger than the length of the first piece 35 in the left-right direction. Therefore, the connecting portion between the first piece 35 and the second piece 36 is arranged on the left side of the central portion of the first plate-like portion 31 in the left-right direction.

[0012] The first piece 35 and the second piece 36 are connected via a steel hinge 40. The hinge 40 rotatably connects two left and right mounting plates 42, 42 to a rotating shaft 41 extending in the tunnel axial direction. Both mounting plates 42, 42 are attached to the inner surfaces of the first piece 35 and the second piece 36, respectively. Thereby, the first piece 35 and the second piece 36 are rotatably connected around the axis of the rotating shaft 41. FIG. 4 is a side view showing a state in which the lower segment is installed in the tunnel in a folded state in the construction method of the tunnel lining structure according to the embodiment of the present invention. As shown in FIG. 4, a plurality of hinges 40 are arranged at intervals in the tunnel axial direction in the lower segment 30. The number of hinges 40 provided in the lower segment 30 is not limited and is appropriately set according to the size and weight of the first piece 35 and the second piece 36. As shown in FIG. 5, at the connecting portion between the first piece 35 and the second piece 36, resin waterstops 50, 50 are respectively attached to the left side surface of the first piece 35 and the right side surface of the second piece 36. In this way, the first piece 35 and the second piece 36 are connected via the waterstop 50. Also, at the connecting portion between the first piece 35 and the second piece 36, a steel connecting member 60 is provided. The connecting member 60 is a bolt having a thread groove formed on its outer peripheral surface. The left half of the connecting member 60 is screwed into a threaded hole formed on the right side surface of the first piece 35. Also, the right half of the connecting member 60 is screwed into a threaded hole formed on the left side surface of the second piece 36. The connecting member 60 is disposed at the central portion in the thickness direction of the first plate-like portion 31. In this way, in the lower segment 30 of the present embodiment, the connecting member 60, the first piece 35, and the second piece 36 are connected by a bolt joint.

[0013] Both second plate-like portions 32a, 32b of the lower segment 30 are steel plate-like members that project upward from the left and right edges of the first plate-like portion 31, and are provided with a skin plate, a main girder, ribs, joint plates, and the like. Both second plate-like portions 32a, 32b are formed perpendicular to the first plate-like portion 31. The left second plate-like portion 32a is a portion that covers the lower part of the left side surface of the rectangular tunnel 2, and the right second plate-like portion 32b is a portion that covers the lower part of the right side surface of the rectangular tunnel 2. In the lower segment 30 of the present embodiment, the vertical length of the left second plate-like portion 32a is formed to be larger than the vertical length of the right second plate-like portion 32b. The vertical length of the left second plate-like portion 32a is formed to be approximately the same as the horizontal length of the second piece 36. Also, the vertical length of the right second plate-like portion 32b is formed to be approximately the same as the horizontal length of the first piece 35. FIG. 3 is a front view showing a state in which the lower segment is installed in the tunnel in a folded state in the construction method of the tunnel lining structure according to the embodiment of the present invention. Regarding the lower segment 30 before installation in the rectangular tunnel 2, as shown in FIG. 3, when the first piece 35 is rotated 90 degrees inward (to the right) with respect to the second piece 36, the first piece 35 and the second plate-shaped portion 32b on the right are arranged in parallel with a space therebetween in the left-right direction. Also, the second piece 36 and the second plate-shaped portion 32a on the left are arranged in parallel with a space therebetween in the up-down direction. In this way, the lower segment 30 before installation in the rectangular tunnel 2 can be deformed into a rectangular cylindrical shape. When transporting the lower segment 30 in a cylindrical state, it can be maintained in a cylindrical shape by fixing the left and right second plate-shaped portions 32a and 32b to each other by fixing means such as a wire. As shown in FIG. 5, the upper end surfaces of both second plate-shaped portions 32a and 32b of the lower segment 30 are inclined such that the inner edge portion is positioned below the outer edge portion. Also, resin-made waterstops 50, 50 are respectively attached to the upper end surfaces of both second plate-shaped portions 32a and 32b.

[0014] As shown in FIG. 2, the upper segment 20 includes a first plate-shaped portion 21 and two left and right second plate-shaped portions 22a and 22b respectively erected on the left and right side edges of the first plate-shaped portion 21. The upper segment 20 is formed in a U-shaped shape that opens downward. The upper segment 20 and the lower segment 30 are formed to face each other vertically. The first plate-shaped portion 21 of the upper segment 20 is a steel plate-shaped member that covers the top surface of the rectangular tunnel 2, and is divided into a left first piece 25 and a right second piece 26, similar to the first plate-shaped portion 31 of the lower segment 30. The upper segment 20 is formed such that the length of the first piece 25 in the left-right direction is larger than the length of the second piece 26 in the left-right direction, and the connecting portion between the first piece 25 and the second piece 26 is arranged on the right side of the center of the first plate-shaped portion 21 in the left-right direction. Also, similar to the first plate-shaped portion 31 of the lower segment 30, the first piece 25 and the second piece 26 of the first plate-shaped portion 21 of the upper segment 20 are rotatably connected by a hinge 40. In addition, the first piece 25 and the second piece 26 of the upper segment 20 are also connected via a water stop material 50, and a connecting member 60 is also provided at the connecting portion between the first piece 25 and the second piece 26.

[0015] Both second plate-like portions 22a and 22b of the upper segment 20 project vertically downward from the left and right edge portions of the first plate-like portion 21, respectively. The left second plate-like portion 22a is a steel plate-like member that covers the upper part of the left side surface of the rectangular tunnel 2, and the right second plate-like portion 22b is a steel plate-like member that covers the upper part of the right side surface of the rectangular tunnel 2. In the upper segment 20 of the present embodiment, the vertical length of the right second plate-like portion 22a is formed to be larger than the vertical length of the left second plate-like portion 22b. The vertical length of the left second plate-like portion 22a is formed to be approximately the same as the horizontal length of the second piece 26. Also, the vertical length of the right second plate-like portion 22b is formed to be approximately the same as the horizontal width of the first piece 25. FIG. 6 is a front view showing a state in which the upper segment is installed in the tunnel in a folded state in the construction method of the tunnel lining structure according to the embodiment of the present invention. Regarding the upper segment 20 before installation in the rectangular tunnel 2, as shown in FIG. 6, when the second piece 26 is rotated 90 degrees inward (left side) with respect to the first piece 25, the second piece 26 and the left second plate-like portion 22a are arranged in parallel with a space therebetween in the horizontal direction. Also, the first piece 25 and the right second plate-like portion 22b are arranged in parallel with a space therebetween in the vertical direction. In this way, the upper segment 20 before installation in the rectangular tunnel 2 can be deformed into a rectangular tubular shape. When transporting the upper segment 20 in a tubular state, the left and right second plate-like portions 22a and 22b can be fixed by fixing means such as wires to maintain the upper segment 20 in a tubular shape. As shown in FIG. 2, the lower end surfaces of both second plate-like portions 22a and 22b of the upper segment 20 are inclined such that the inner edge portion is located above the outer edge portion. Also, resin water stop materials 50, 50 are respectively attached to the lower end surfaces of both second plate-like portions 32a, 32b.

[0016] In the tunnel lining structure 10 of the present embodiment, the lower end surface of the second plate-shaped portion 22a on the left side of the upper segment 20 and the upper end surface of the second plate-shaped portion 32a on the left side of the lower segment 30 are connected via a waterstop material 50, and a connecting member 60 is provided at the connecting portion. Similarly, the lower end surface of the second plate-shaped portion 22b on the right side of the upper segment 20 and the upper end surface of the second plate-shaped portion 32b on the right side of the lower segment 30 are connected via a waterstop material 50, and a connecting member 60 is provided at the connecting portion. In this way, by arranging and connecting the upper segment 20 and the lower segment 30 so as to face each other vertically, a tunnel lining structure 10 formed in a rectangular tubular shape is formed.

[0017] Next, a construction method of the tunnel lining structure 10 of the present embodiment will be described. (Preparation process) First, as shown in FIG. 3, the lower segment 30 is prepared in a deformed cylindrical state, and as shown in FIG. 6, the upper segment 20 is prepared in a deformed cylindrical state. As shown in FIG. 1, after improving the ground around the underground structure 3, a rectangular tunnel 2 is constructed by an open shield machine 4.

[0018] (First assembly process) As shown in FIG. 4, behind the open shield machine 4, the claw portion F1 of the forklift F is inserted into the cylindrical lower segment 30, and as shown in FIG. 3, the claw portion F1 is hooked on the lower surface of the second plate-shaped portion 32a. Then, the lower segment 30 is placed at a predetermined position in the rectangular tunnel 2 by the forklift F. Thereby, the second piece 36 of the lower segment 30 is overlapped on the bottom surface of the rectangular tunnel 2, and the second plate-shaped portion 32b on the right side is overlapped on the right side surface of the rectangular tunnel 2. Thereafter, as shown in FIG. 5, the first piece 35 of the lower segment 30 is rotated 90 degrees outward (to the left) with respect to the second piece 36, and the first plate-like portion 31 is opened flat. In this way, the first piece 35 is overlapped on the bottom surface of the rectangular tunnel 2, and the left second plate-like portion 32a is overlapped on the left side surface of the rectangular tunnel 2. Further, the first piece 35 and the second piece 36 of the lower segment 30 are fixed by a connecting member 60.

[0019] (Second assembly process) FIG. 7 is a side view showing a state in which the upper segment is installed in the tunnel in a folded state in the construction method of the tunnel lining body according to the embodiment of the present invention. Subsequently, as shown in FIG. 7, behind the open shield machine 4, the claw portion F1 of the forklift F is inserted into the cylindrical upper segment 20, and as shown in FIG. 6, the claw portion F1 is hooked on the lower surface of the first piece 25. Then, the upper segment 20 is placed at a predetermined position in the rectangular tunnel 2 by the forklift F. Thereby, the first piece 25 of the upper segment 20 is overlapped on the top surface of the rectangular tunnel 2, and the left second plate-like portion 32a is overlapped on the left side surface of the rectangular tunnel 2. Thereafter, as shown in FIG. 1, the second piece 26 of the upper segment 20 is rotated 90 degrees outward (to the right) with respect to the first piece 25, and the first plate-like portion 21 is opened flat. In this way, the second piece 26 is overlapped on the top surface of the rectangular tunnel 2, and the right second plate-like portion 32b is overlapped on the left side surface of the rectangular tunnel 2. Further, the first piece 25 and the second piece 26 of the upper segment 20 are fixed by a connecting member 60. Furthermore, the left second plate-like portion 22a of the upper segment 20 and the left second plate-like portion 32a of the lower segment 30 are fixed by a connecting member 60, and the right second plate-like portion 22b of the upper segment 20 and the right second plate-like portion 32b of the lower segment 30 are connected via a connecting member 60. In this way, by connecting the upper segment 20 and the lower segment 30 to face each other vertically, the tunnel lining body 10 formed in a rectangular tubular shape can be provided in the rectangular tunnel 2.

[0020] In the tunnel lining body 10 and the construction method as described above, as shown in FIGS. 3 and 6, by folding the upper segment 20 and the lower segment 30 to deform them compactly, the upper segment 20 and the lower segment 30 can be easily transported within the rectangular tunnel 2 with a small cross-section. Thereby, since the working efficiency when assembling the upper segment 20 and the lower segment 30 can be improved, the construction period of the shield method can be shortened. Further, in the tunnel lining body 10 of the present embodiment, as shown in FIG. 3, after positioning the second piece 36 of the lower segment 30 within the rectangular tunnel 2, as shown in FIG. 5, when the first piece 35 and the second piece 36 are opened, the first piece 35 is also positioned within the rectangular tunnel 2. Similarly, as shown in FIG. 6, after positioning the first piece 25 of the upper segment 20 within the rectangular tunnel 2, as shown in FIG. 1, when the first piece 25 and the second piece 26 are opened, the second piece 26 is also positioned within the rectangular tunnel 2. Moreover, in the tunnel lining body 10 of the present embodiment, the upper end surfaces of both second plate-shaped portions 32a, 32b of the lower segment 30 and the lower end surfaces of both second plate-shaped portions 22a, 22b of the upper segment 20 are inclined such that the inner edge portions are positioned lower than the outer edge portions. Thereby, after installing the lower segment 30 within the rectangular tunnel 2, when the upper segment 20 is carried into the rectangular tunnel 2 and the upper segment 20 is opened, the lower end surfaces of both second plate-shaped portions 22a, 22b of the upper segment 20 can be easily overlapped with the upper end surfaces of both second plate-shaped portions 32a, 32b of the lower segment 30. In addition, in the construction method of the tunnel lining structure 10 of the present embodiment, as shown in FIGS. 4 and 7, the claw portions F1 of the forklift F are inserted into the upper segment 20 and the lower segment 30 folded in a tubular shape, respectively, and the upper segment 20 and the lower segment 30 are transported by the forklift F, so that the work efficiency can be improved. Further, by deforming the upper segment 20 and the lower segment 30 into a rectangular tubular shape, it is easy to take the center of gravity of the upper segment 20 and the lower segment 30, so that the upper segment 20 and the lower segment 30 can be stably transported and installed.

[0021] In the tunnel lining structure 10 of the present embodiment, as shown in FIG. 1, the first pieces 25, 35 and the second pieces 26, 36 are connected via the water stop material 50. Further, both the second plate-shaped portions 22a, 22b of the upper segment 20 and both the second plate-shaped portions 32a, 32b of the lower segment 30 are connected via the water stop material 50. Thereby, the water tightness of each connecting portion of the tunnel lining structure 10 can be enhanced.

[0022] In the tunnel lining structure 10 of the present embodiment, a connecting member 60 is provided at the connecting portion between the first pieces 25, 35 and the second pieces 26, 36. Further, a connecting member 60 is provided at the connecting portion between both the second plate-shaped portions 22a, 22b of the upper segment 20 and both the second plate-shaped portions 32a, 32b of the lower segment 30. In addition, in the tunnel lining structure 10 of the present embodiment, hinges 40 are attached to the inner surfaces of the first pieces 25, 35 and the second pieces 26, 36. Further, the hinge 40 is disposed at a portion where positive bending occurs inward in the first plate-shaped portions 21, 31. In this configuration, the moment arm length becomes larger than when the hinge 40 is attached to the outer surfaces of the first pieces 25, 35 and the second pieces 26, 36. Thereby, in the tunnel lining structure 10 of the present embodiment, the strength of each connecting portion of the tunnel lining structure 10 can be enhanced.

[0023] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be appropriately modified without departing from the gist thereof. In the tunnel lining structure 10 of the present embodiment, as shown in FIG. 1, the upper segment 20 and the lower segment 30 are arranged to face each other vertically. However, a rectangular tubular tunnel lining structure may be formed by arranging the two segments to face each other horizontally. In the tunnel lining structure 10 of the present embodiment, the connecting member 60, the first piece 35, and the second piece 36 are connected by a bolt joint. However, the connecting member 60, the first piece 35, and the second piece 36 may be connected by a pin joint. In the construction method of the tunnel lining structure 10 of the present embodiment, as shown in FIGS. 4 and 7, the forklift F is used to transport the upper segment 20 and the lower segment 30. However, the conveying means for the upper segment 20 and the lower segment 30 is not limited.

Explanation of Reference Numerals

[0024] 2 Rectangular tunnel 3 Underground structure 4 Open shield machine 5 Earth retaining wall 10 Tunnel lining structure 20 Upper segment 21 First plate-like part 22a Left second plate-like part 22b Right second plate-like part 25 First piece 26 Second piece 30 Lower segment 31 First plate-like part 32a Left second plate-like part 32b Right second plate-like part 35 First piece 36 Second piece 40 Hinge 41 Rotation axis 42 Mounting plate 50 Sealing material 60 Connecting member F Forklift F1 Claw part

Claims

1. A tunnel lining formed in a rectangular cylindrical shape by arranging two segments facing each other, wherein the segment comprises a first plate-like portion, and two second plate-like portions respectively erected on both side edges of the first plate-like portion, and end faces of the second plate-like portions of both segments are connected to each other, the first plate-like portion is divided into a first piece on one second plate-like portion side and a second piece on the other second plate-like portion side, the tunnel lining is characterized in that the first piece and the second piece are connected by a hinge having a rotation axis extending in the tunnel axis direction.

2. The tunnel lining according to claim 1, characterized in that the segment can be deformed into a rectangular cylindrical shape by folding the first piece and the second piece at the hinge.

3. The tunnel lining according to claim 1, characterized in that the hinge is attached to the inner surfaces of the first piece and the second piece.

4. A connecting member is provided at a connecting portion between the first piece and the second piece, the tunnel lining according to claim 1, characterized in that the connecting member is inserted into a hole portion of the first piece and also inserted into a hole portion of the second piece.

5. The end face of the second plate-like portion of one segment is inclined such that the inner edge portion is positioned below the outer edge portion, the tunnel lining according to claim 1, characterized in that the end face of the second plate-like portion of the other segment is inclined such that the inner edge portion is positioned below the outer edge portion.

6. The tunnel lining according to claim 1, characterized in that the first piece and the second piece are connected via a waterstop material.

7. A construction method of the tunnel lining according to claim 1, comprising a step of folding the first piece and the second piece to prepare the two segments in a state where each is deformed into a cylindrical shape, a first assembling step of opening the first piece and the second piece in one segment and deforming the first plate-like portion into a flat shape, a second assembling step of opening the first piece and the second piece in the other segment, deforming the first plate-like portion into a flat shape, and connecting end faces of the second plate-like portions of both segments, and is characterized by comprising these steps.

8. The construction method of the tunnel lining structure according to claim 7, characterized in that the claw part of a forklift is inserted into the segment folded in a cylindrical shape, and the segment is transported by the forklift.

9. The construction method of the tunnel lining structure according to claim 7, characterized in that the ground with ground improvement is excavated by an open shield machine, and the first assembly process and the second assembly process are performed behind the open shield machine.

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