JP2019157617A - Segment, structure and assembly method of structure - Google Patents

Abstract

To restrain a position deviation between adjacent segments.SOLUTION: A segment 10 comprises a cylindrical outer peripheral surface having an outer shape in recessed polygonal shape. The outer peripheral surface comprises a first outer peripheral surface 11 and a second outer peripheral surface 12 that overlap in symmetrical translation and parallel translation. The first outer peripheral surface 11 has at least one protrusion part 10aa projecting toward outer peripheral side and the second outer peripheral surface 12 has at least one recessed part 10ab recessed toward inner peripheral side. In addition, a structure 100 comprises a plurality of segments 10.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a segment, a structure, and a method for assembling the structure.

  Conventionally, a steel segment that is connected in the tunnel circumferential direction and the tunnel axial direction to form a cylindrical structure in the tunnel is known (see, for example, Patent Document 1).

  Patent Document 1 discloses a skin plate that is curved along the inner periphery of the tunnel, a pair of main girders that are erected along both sides of the tunnel in the longitudinal direction of the skin plate, A steel segment having a steel frame formed in a substantially rectangular shape by a pair of joint plates erected along an edge is disclosed.

  According to the steel segment disclosed in Patent Document 1, since the frame is formed in a substantially rectangular shape, positional displacement between adjacent segments is suppressed by connecting adjacent segments with bolts and nuts. There is a need to.

JP 2010-138877 A

  An object of this invention is to provide the segment which can suppress the position shift between adjacent segments, the structure provided with this segment, and the assembly method of a structure.

  One embodiment of the present invention is a segment including an outer peripheral surface having a concave polygonal outer shape. The outer peripheral surface includes a first outer peripheral surface and a second outer peripheral surface that overlap each other when moved symmetrically or translated. The first outer peripheral surface includes at least one convex portion protruding toward the outer peripheral side, and the second outer peripheral surface includes at least one concave portion recessed toward the inner peripheral side.

  Since the outer peripheral surface of the segment described above has a concave polygonal outer shape, it includes a concave portion that is recessed toward the inner peripheral side. Therefore, when arranging a plurality of segments side by side, two adjacent segments can be arranged such that the convex portion of one segment and the concave portion of the other segment are engaged with each other. For this reason, it is possible to reduce the direction in which one segment is displaced relative to the other segment between two adjacent segments. Therefore, it is easy to suppress positional deviation between two adjacent segments.

  The first outer peripheral surface includes at least one concave portion adjacent to at least one convex portion and recessed toward the inner peripheral side, and the second outer peripheral surface is adjacent to at least one concave portion and directed toward the outer peripheral side. It is preferable to include at least one convex portion that protrudes. Since each outer peripheral surface includes adjacent convex portions and concave portions, each outer peripheral surface can be formed in a zigzag shape. Therefore, it is easier to suppress the positional deviation between two adjacent segments.

  The outer shape of the outer peripheral surface preferably includes an outline having a shape in which a plurality of hexagons are arranged in a row so that one side of adjacent hexagons overlap. Since the outer shape of the outer peripheral surface includes a plurality of hexagonal contours connected in a row, the first outer peripheral surface and the second outer peripheral surface overlap each other when moved symmetrically, and the convex portions of both outer peripheral surfaces face each other, The recesses face each other. For this reason, a honeycomb structure can be formed by arranging a plurality of segments. Therefore, it is possible to provide a segment which is structurally stable.

  The outer peripheral surface preferably includes a groove portion that cuts out at least a part of the outer periphery in the circumferential direction. It becomes possible to arrange a water-stopping material or the like in the groove, and improve the water-stopping between adjacent outer peripheral surfaces.

  The outer peripheral surface preferably includes a flat third outer peripheral surface that connects one ends of the first outer peripheral surface and the second outer peripheral surface, and a flat fourth outer peripheral surface that connects the other ends. When the two segments are adjacent to each other, the flat outer peripheral surface of one segment can be slid with respect to the flat outer peripheral surface of the other segment. Therefore, a plurality of segments can be arranged side by side efficiently.

  The circumferential widths of the first outer circumferential surface and the second outer circumferential surface are preferably larger than the circumferential widths of the third outer circumferential surface and the fourth outer circumferential surface. Between two adjacent segments, the contact area by the first outer peripheral surface and the second outer peripheral surface can be made larger than the contact area by the third outer peripheral surface and the fourth outer peripheral surface. Therefore, it is easy to make the segment compact while suppressing misalignment.

  The outer peripheral surface is preferably an outer wall surface of a cylindrical peripheral wall. By making the outer peripheral surface the outer wall surface of the cylindrical peripheral wall, the weight of the segment can be reduced.

  The segment preferably includes a blocking wall that closes one opening of the cylindrical peripheral wall. When the blocking wall closes one opening of the peripheral wall, the bending strength of the segment can be increased and the outer shape of the segment can be easily maintained.

  The circumferential width of each of the first outer peripheral surface and the second outer peripheral surface is preferably larger on the closing side than on the opening side. By laying out segments whose width on the closing side is larger than the width on the opening side, a structure with the closing side facing outward can be obtained.

  The segment preferably includes an inner wall that connects the concave portions facing each other. The strength of the segment can be improved by connecting the concave portions facing each other on the outer peripheral surfaces of the inner wall.

  The peripheral wall preferably includes a through hole penetrating the outer peripheral surface. By using the through holes, adjacent segments can be fastened with a fastener or the like.

  Another aspect of the present invention is a structure that includes a plurality of the above-described segments, and the plurality of segments are arranged along the inner wall of the tunnel. By using the above-described segment, it is possible to provide a structure in which positional deviation between adjacent segments is suppressed.

  Another aspect of the present invention is a method of assembling a structure using a plurality of segments and an arm portion that rotationally moves each of the segments along the inner wall of the tunnel. This assembling method includes a first assembling step for assembling the first arched structure by rotating each of the segments, and a second assembling the second arched structure by rotating each of the segments. Assembly process. The second assembly step includes a step of moving the arm portion to a position where it does not interfere with the first arched structure, and a first segment that is rotated immediately before and brought into contact with the first arched structure. Rotating the second segment to the first position of the second position, and moving the second segment from the first position to the second position contacting the first arched structure by moving the arm portion. And a step of causing.

  By moving a plurality of segments one by one from the first position to the second position, the first arch-shaped structure and the second arch-shaped structure can be efficiently contacted. Therefore, the structure can be efficiently assembled by repeating the first assembly process and the second assembly process.

  Another aspect of the present invention is a method of assembling a structure using a plurality of segments and an arm portion that rotationally moves each of the segments along the inner wall of the tunnel. The assembling method includes a step of assembling the first arched structure by rotating and moving each of the segments, a step of moving the arm portion to a position where it does not interfere with the first arched structure, and each of the segments. Assembling the second arch-like structure by rotating and bringing the second arch-like structure into contact with the first arch-like structure.

  Since the second arch-shaped structure can be integrally brought into contact with the first arch-shaped structure after the second arch-shaped structure is assembled at a position where it does not interfere with the first arch-shaped structure. The structure can be assembled efficiently.

  Another aspect of the present invention is a segment having a cylindrical peripheral wall. The outer shape of the peripheral wall includes a contour of a shape in which a plurality of hexagons are arranged in a line so that one side of adjacent hexagons overlap. The peripheral wall includes a first side wall adjacent to a convex portion protruding toward the outer peripheral side and a concave portion recessed toward the inner peripheral side, a second side wall obtained by symmetrically moving the first side wall, and the first side wall. And a flat third side wall connecting one ends of the second side wall and a flat fourth side wall connecting the other ends. The segment further includes a first inner wall that connects the convex portions facing each other on the first side wall and the second side wall.

  In the above-described segment, since the outer shape of the cylindrical peripheral wall includes a plurality of hexagonal outlines connected in a row, the first side wall and the second side wall overlap each other when they are moved symmetrically, and convex portions on both side walls. They face each other and the recesses face each other. For this reason, a honeycomb structure can be formed by arranging a plurality of segments. Therefore, it is possible to provide a segment which is structurally stable. Furthermore, this segment is provided with the 1st inner wall which connects the convex parts which the 1st and 2nd side walls oppose. Therefore, the segments are spread so that the first and second side walls are along the circumferential direction of the arch-shaped structure, and external force acts on the arch-shaped structure from above, and the third and fourth are applied to each segment. When a compressive force is applied in a direction in which the side walls of the first and second side walls are brought closer to each other, the first inner wall resists deformation in which the convex portions facing each other try to move away from each other. Therefore, deformation of the segment can be suppressed and the honeycomb structure can be easily held.

  Another aspect of the present invention is a segment having a cylindrical peripheral wall. The outer shape of the peripheral wall includes a contour of a shape in which a plurality of hexagons are arranged in a line so that one side of adjacent hexagons overlap. The peripheral wall includes a first side wall adjacent to a convex portion protruding toward the outer peripheral side and a concave portion recessed toward the inner peripheral side, a second side wall obtained by symmetrically moving the first side wall, and the first side wall. And a flat third side wall connecting one ends of the second side wall and a flat fourth side wall connecting the other ends. The segment further includes a second inner wall connecting the third side wall and the fourth side wall.

  In the above-described segment, since the outer shape of the cylindrical peripheral wall includes a plurality of hexagonal outlines connected in a row, the first side wall and the second side wall overlap each other when they are moved symmetrically, and convex portions on both side walls. They face each other and the recesses face each other. For this reason, a honeycomb structure can be formed by arranging a plurality of segments. Therefore, it is possible to provide a segment which is structurally stable. The segment further includes a second inner wall connecting the third and fourth side walls. Therefore, the segments are spread so that the first and second side walls are along the circumferential direction of the arch-shaped structure, and external force acts on the arch-shaped structure from above, and the third and fourth are applied to each segment. When a compressive force is applied in a direction in which the side walls are brought closer to each other, the second inner wall resists deformation in which the third and fourth side walls try to approach each other. Therefore, deformation of the segment can be suppressed and the honeycomb structure can be easily held.

  Another aspect of the present invention is a segment having a cylindrical peripheral wall. The outer shape of the peripheral wall includes a contour of a shape in which a plurality of hexagons are arranged in a line so that one side of adjacent hexagons overlap. The peripheral wall includes a first side wall adjacent to a convex portion protruding toward the outer peripheral side and a concave portion recessed toward the inner peripheral side, a second side wall obtained by symmetrically moving the first side wall, and the first side wall. And a flat third side wall connecting one ends of the second side wall and a flat fourth side wall connecting the other ends. The segment further includes a projecting portion that projects from the convex portion of the first side wall and the second side wall toward the inner peripheral side so as to cover a part of one opening of the cylindrical peripheral wall.

  In the above-described segment, since the outer shape of the cylindrical peripheral wall includes a plurality of hexagonal outlines connected in a row, the first side wall and the second side wall overlap each other when they are moved symmetrically, and convex portions on both side walls. They face each other and the recesses face each other. For this reason, a honeycomb structure can be formed by arranging a plurality of segments. Therefore, it is possible to provide a segment which is structurally stable. Further, this segment includes an overhanging portion that protrudes toward the inner peripheral side from the convex portions of the first and second side walls. Therefore, the segments are spread so that the first side wall and the second side wall are along the circumferential direction of the arch-shaped structure, and an external force acts on the arch-shaped structure from above. When a compressive force acts in a direction in which the fourth side walls are brought closer to each other, the overhanging portion resists deformation in which the inner angle of the convex portion tends to narrow. Therefore, deformation of the segment can be suppressed and the honeycomb structure can be easily held.

  ADVANTAGE OF THE INVENTION According to this invention, the segment which can suppress the position shift between adjacent segments, the structure provided with this segment, and the assembly method of a structure can be provided.

FIG. 1 is a schematic perspective view of a tunnel-like structure including the structure according to the embodiment. FIG. 2 is a perspective view of the segment. FIG. 3 is an explanatory diagram showing an example of how to arrange segments. FIG. 4 is a front view of the segment. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a rear view of the segment. 7 is a cross-sectional view taken along line VII-VII in FIG. FIG. 8 is an explanatory diagram showing an example of segment combination. FIG. 9 is an explanatory diagram showing a modification of the segment. FIG. 10 is an explanatory view showing a modification of the peripheral wall of the segment. FIG. 11 is an explanatory view showing a modification of the inner wall of the segment. FIG. 12 is an explanatory diagram 1 showing a method of assembling the structure. FIG. 13 is an explanatory diagram 2 showing a method of assembling the structure. FIG. 14 is a flowchart showing the procedure of the assembling method. FIG. 15 is an explanatory diagram 1 showing a modification of the assembling method. FIG. 16 is a second explanatory diagram showing a modification of the assembling method. FIG. 17 is a flowchart showing the procedure of a modified example of the assembling method. FIG. 18 is an explanatory diagram showing a first variation of the concave polygon. FIG. 19 is an explanatory view showing a variation 2 of the concave polygon. FIG. 20 is an explanatory view showing a variation 3 of the concave polygon. FIG. 21 is an explanatory view showing a variation 4 of the concave polygon. FIG. 22 is an explanatory view showing a variation 5 of the concave polygon. FIG. 23 is an explanatory diagram showing a variation 6 of the concave polygon. FIG. 24 is an explanatory view showing variation 7 of the concave polygon. FIG. 25 is a perspective view showing another modified example 1 of the segment. FIG. 26 is a perspective view showing a modification of the first inner wall shown in FIG. FIG. 27 is a perspective view showing another modification 2 of the segment. FIG. 28 is a perspective view showing another modification 3 of the segment. 29 is a cross-sectional view taken along line XXIX-XXIX in FIG. FIG. 30 is a perspective view showing a first modification of the overhang portion shown in FIG. 31 is a cross-sectional view taken along line XXXI-XXXI in FIG. FIG. 32 is a perspective view showing a second modification of the overhang portion shown in FIG. 33 is a cross-sectional view taken along line XXXIII-XXXIII in FIG. FIG. 34 is a perspective view showing a first modification of the through hole shown in FIG. FIG. 35 is a perspective view showing a second modification of the through hole shown in FIG. FIG. 36 is a perspective view showing a third modification of the through hole shown in FIG. FIG. 37 is a perspective view showing a first modification of the opening shown in FIG. 38 is a perspective view showing a second modification of the opening shown in FIG.

  Hereinafter, embodiments of a segment, a structure, and a method for assembling the structure disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

  In the embodiment described below, expressions such as “symmetric”, “match”, or “overlap” are used, but it is not strictly required to be “symmetric”, “match”, or “overlap”. In other words, each expression described above allows a deviation in manufacturing accuracy, installation accuracy, and the like.

  In the embodiment described below, a hollow structure segment is mainly described, but a solid structure segment may be used.

  First, a tunnel-like structure 1 including a structure 100 according to an embodiment will be described with reference to FIG. FIG. 1 is a schematic perspective view of a tunnel-like structure 1 including a structure 100 according to an embodiment. In addition, in FIG. 1, the description of the earth and sand and the rock mass in the outer peripheral side of the tunnel-like structure 1 is abbreviate | omitted.

  For reference, FIG. 1 shows an rθz cylindrical coordinate system in which the z-axis coincides with the center axis C of the tunnel. Hereinafter, the θ direction may be referred to as “circumferential direction θ”, the r direction as “radial direction r”, and the z direction as “axial direction z”.

  The tunnel-like structure 1 can be a cylindrical or arcuate structure, but FIG. 1 shows an arch-like structure that is an upwardly convex arc shape. Moreover, the tunnel-like structure 1 is located on the inner circumferential side of the existing lining layer 600, the filling layer 500 located on the inner circumferential side of the existing lining layer 600, and the inner circumferential side of the filling layer 500 from the outer circumferential side to the inner circumferential side. The structure 100 is provided.

  The existing lining layer 600 is formed by, for example, sequentially laying out segments while excavating earth and sand or rock with a shield machine. Here, the segment is a segment made of, for example, steel, concrete, cast iron, or a composite structure. The filling layer 500 is formed, for example, by filling a filler such as mortar between the inner periphery of the existing lining layer 600 and the outer periphery of the structure 100.

  The structure 100 is formed by spreading the segments 10 on the inner peripheral side of the existing lining layer 600 with a gap for the filling layer 500. In the present embodiment, the case where the structure 100 is used for the purpose of reinforcing the existing lining layer 600 will be described. However, the present invention is not limited to this, and in the case of a new installation, the existing lining layer 600 may be replaced with the structure 100.

  Here, the segment 10 can be made of steel, aluminum, urethane, concrete, or fiber reinforced plastic (FRP). However, it is economical when manufactured with cast iron having a hollow structure, light, and easy to work. Good. For this reason, the segment 10 made of cast iron and having a hollow structure will be described below.

  Next, the hollow segment 10 will be described in detail with reference to FIG. The basic configuration is the same even for a solid structure. FIG. 2 is a perspective view of the segment 10. FIG. 2 is a perspective view of the segment 10 as viewed from the inside in the radial direction r.

  As shown in FIG. 2, the segment 10 includes a cylindrical peripheral wall 10a having a concave polygonal outer shape. Here, the concave polygon is a polygon having at least one concave angle (inner angle larger than 180 °). That is, the peripheral wall 10a includes a convex portion protruding toward the outer peripheral side of the segment 10 and a concave portion recessed toward the inner peripheral side.

  Here, a convex part is a part comprised only by one convex angle (inner angle smaller than 180 degrees) in a concave polygon, or a part comprised only by several continuous convex angles. Moreover, a recessed part is a site | part comprised only from one concave angle in a concave polygon, or a site | part comprised only from several continuous concave angles. Note that FIG. 2 shows a case where the convex angle and the concave angle are angular, but a rounded shape may be used. That is, the convex part or the concave part may include a rounded corner (a corner with R).

  Next, how to arrange the segments 10 will be described with reference to FIG. FIG. 3 is an explanatory diagram showing an example of how the segments 10 are arranged. FIG. 3 shows a perspective view of the segment 10 as seen from the outside in the radial direction r (see FIG. 1). In FIG. 3, the two segments 10 arranged in the circumferential direction θ are indicated by solid lines, and the two segments 10 arranged in the axial direction z are indicated by broken lines. In addition, although the case where the longitudinal direction of the segment 10 was arranged along the circumferential direction (theta) was shown in FIG. 3, it is good also as arranging a longitudinal direction along the axial direction z. In the following, the configuration shown in FIG. 2 will be described as appropriate.

  As shown in FIG. 3, the plurality of segments 10 in the circumferential direction θ are arranged so that the outer peripheral surfaces are in contact with each other. Further, the plurality of segments 10 in the axial direction z are arranged shifted in the circumferential direction θ so that the concave portion and the convex portion are engaged with each other. Thus, by arranging the segments 10, the segments 10 can be spread in a semi-cylindrical shape.

  Thus, since the surrounding wall 10a is provided with a convex part and a recessed part, when arranging the segment 10 in order, two adjacent segments 10 are made into the convex part of one segment 10, and the recessed part of the other segment 10 And can be arranged so as to mesh with each other.

  For this reason, it is possible to reduce the direction in which one segment 10 is displaced relative to the other segment 10 between two adjacent segments 10. Therefore, it is easy to suppress the positional deviation between the two adjacent segments 10.

  Further, since the peripheral wall 10a of the segment 10 has a concave polygonal outer shape as described above, the direction in which the outer peripheral surfaces in contact with adjacent segments 10 face each other is multi-directional when a plurality of segments 10 are arranged side by side. can do.

  Specifically, since the stress acting on the peripheral wall 10a of the segment 10 is transmitted through the adjacent outer peripheral surface, the rectangular outer shape can be obtained by making the directions in which the adjacent outer peripheral surfaces face each other in multiple directions. The transmission direction of stress can be increased as compared with the segment having the same. Therefore, the stress acting on the peripheral wall 10a can be easily dispersed and transmitted in multiple directions, and the stress transmissibility to adjacent segments can be easily improved.

  Here, as shown in FIG. 2, the convex portion and the concave portion in the peripheral wall 10a are not only a part of the region (for example, protrusions and dents on the surface) in the radial direction r of the peripheral wall 10a, but the radial direction r. It is formed so as to reach both ends in the radial direction r throughout. Therefore, when arranging a plurality of segments 10 side by side, accurate alignment for meshing becomes unnecessary. Further, local stress concentration, which is likely to occur when a protrusion is provided on the surface, can be reduced.

  In addition, as shown in FIG. 2, the segment 10 is provided with the obstruction | occlusion wall 10b which has the obstruction | occlusion surface which obstruct | occludes one opening of the surrounding wall 10a. Thus, by providing the blocking wall 10b, the bending strength of the segment 10 can be increased, and the outer shape of the segment 10 can be easily maintained. 2 shows a case where the blocking wall 10b is provided so as to close the opening on the outer side in the radial direction r, but the blocking wall 10b may be provided so as to close the inner opening.

  When the blocking wall 10b is provided so as to close the outer opening, the filler can be easily filled and the filling amount can be reduced. On the other hand, when the blocking wall 10b is provided so as to close the inner opening, it is effective when a fluid such as rain water flows through the tunnel like a river tunnel.

  Moreover, as shown in FIG. 2, the segment 10 is provided with the inner wall 10c which connects the recessed parts which oppose. By providing the inner wall 10c, the strength of the segment 10 can be increased. Moreover, since the inner wall 10c connects the recessed parts which oppose, the inner wall 10c can be shortened rather than the case where convex parts are connected, and the intensity | strength of inner wall 10c itself can be raised. Moreover, when the convex part of the adjacent segment 10 is received in the concave part, the stress from the convex part can be transmitted smoothly, and the deformation of the segment 10 can be suppressed.

  Here, when providing the above-mentioned blocking wall 10b, it is preferable that the inner wall 10c is also connected with the blocking wall 10b. This is because the strength of the segment 10 can be further increased by doing in this way. In FIG. 2, the segment 10 including the blocking wall 10b and the inner wall 10c is shown, but the inner wall 10c may be omitted. By omitting the inner wall 10c, the weight of the segment 10 can be reduced. Moreover, although the inner wall 10c which connects the recessed parts which oppose in FIG. 2 was shown, the inner wall 10c may be parted in the middle if it is connected with the surrounding wall 10a, and the width | variety of radial direction r (refer FIG. 1) is It may be smaller than the width of the peripheral wall 10a.

  Next, the shape of the segment 10 shown in FIGS. 2 and 3 will be described in more detail with reference to FIGS. FIG. 4 is a front view of the segment 10. 4 corresponds to a view of the segment 10 as seen from the inside in the radial direction r (see FIG. 1).

  As shown in FIG. 4, the segment 10 has a concave polygonal outer shape. Here, the outer shape has an outline of a shape in which three hexagons are arranged in a line so that one side of adjacent hexagons overlap. That is, by stacking such two-dimensional outlines in the radial direction r (see FIG. 1), a concave polygonal three-dimensional outline is obtained. 4 illustrates a shape in which three hexagons are arranged in a row, but a shape in which two or more arbitrary numbers of hexagons are arranged in an example may be used.

  The peripheral wall 10a that forms such an outer shape includes a first outer peripheral surface 11 and a second outer peripheral surface 12 that overlap each other when moving symmetrically about the symmetry axis S shown in FIG. Moreover, the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 are what is called a zigzag shape which repeats an unevenness | corrugation alternately. And the convex parts 10aa of both outer peripheral surfaces oppose each other, and the concave parts 10ab also oppose each other. Thus, the 1st outer peripheral surface 11 contains the recessed part 10ab adjacent to the convex part 10aa, and the 2nd outer peripheral surface 12 contains the convex part 10aa adjacent to the recessed part 10ab.

  As shown in FIG. 4, the concave portion 10ab and the convex portion 10aa are arranged so as to overlap each other when they move symmetrically. Therefore, the peripheral wall 10a has the concave portion 10ab and the convex portion 10aa that fits into the concave portion 10ab. is doing. For this reason, if a plurality of one type of segments 10 are prepared, the structure 100 (see FIG. 1) can be formed by combining them. Therefore, it is not necessary to manufacture segments with different types of shapes, and it is sufficient to manufacture the segments 10 with one type of shape, so that the manufacturing cost can be suppressed.

  Here, the advantage of the recess 10ab will be described. As shown in FIG. 4, the interior angle α of the recess 10ab is larger than 180 °. Therefore, the reaction force RF with respect to the compressive force received from the adjacent segment 10 has an intersection point CP outside the concave polygon. On the other hand, in the case of a convex polygon, the reaction force RF does not have an intersection CP outside the convex polygon.

  Thus, since the reaction force RF has the intersection CP on the outside of the concave polygon, the concave polygon that is a polygon having the concave portion 10ab acts to sandwich the convex portion 10aa that fits into the concave portion 10ab. . Accordingly, the segment 10 having a concave polygonal shape can be prevented from being misaligned because the concave portions 10ab and the convex portions 10aa of the adjacent segments 10 are firmly fitted.

  In addition, the effect of the above-described concave polygon is an effect that is similarly generated even in the variation of the segment 10 described later with reference to FIGS.

  FIG. 4 shows a case where the first outer peripheral surface 11 and the second outer peripheral surface 12 overlap each other when they move symmetrically. However, the first outer peripheral surface 11 and the second outer peripheral surface 12 are moved in parallel. It is good also as a shape which mutually overlaps. Details of this point will be described later with reference to FIG.

  By the way, the peripheral wall 10a includes a flat third outer peripheral surface 13 that connects one ends of the first outer peripheral surface 11 and the second outer peripheral surface 12, and a flat fourth outer peripheral surface 14 that connects the other ends. It is out. Here, FIG. 4 shows the case where the third outer peripheral surface 13 and the fourth outer peripheral surface 14 are flat, but they may not be flat. Details of this point will be described later with reference to FIG. Since the blocking wall 10b and the inner wall 10c have already been described with reference to FIG. 2, description thereof is omitted here.

  As shown in FIG. 4, the circumferential widths of the peripheral walls 10 a of the first outer peripheral surface 11 and the second outer peripheral surface 12 are respectively the third outer peripheral surface 13 and the fourth outer peripheral surface 14. It is larger than the circumferential width of the peripheral wall 10a.

  By doing in this way, between two adjacent segments 10, the contact area by the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 is made into the contact area by the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14. Can be larger. Therefore, it is easy to make the segment 10 compact while suppressing displacement. Further, when the segments 10 are arranged in the circumferential direction θ to form a ring (an arch-like structure described later), the number of segments 10 included in one ring can be reduced. Thus, by reducing the number per ring, it is possible to reduce the number of assembling steps per ring.

  Next, the sectional shape of the segment 10 shown in FIG. 4 will be described with reference to FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. As shown in FIG. 5, the inner wall 10c is continuous with the peripheral wall 10a so as to be sandwiched between the peripheral walls 10a on both sides. Moreover, the through-hole 10h which penetrates the surrounding wall 10a is formed in the surrounding wall 10a.

  Here, the through holes 10h are respectively provided on the surfaces corresponding to the respective sides in the outer shape of the peripheral wall 10a shown in FIG. Further, the through hole 10h is provided at a position common to each surface such as a central portion of each surface. This is because when the segments 10 are arranged, the through holes 10h of the adjacent segments 10 communicate with each other. In addition, since the through-holes 10h of not less than the adjacent segments 10 but three or more segments 10 communicate, it is also possible to fasten a plurality of segments 10 together.

  The through hole 10h may be provided only in at least one of the first outer peripheral surface 11, the second outer peripheral surface 12, the third outer peripheral surface 13, and the fourth outer peripheral surface 14 shown in FIG. . Further, the through hole 10 h may be omitted from the segment 10. In addition, the utilization method of the through-hole 10h is later mentioned using FIG.

  Next, the case where the segment 10 shown in FIG. 4 is viewed from the back side will be described with reference to FIG. FIG. 6 is a rear view of the segment 10. 6 corresponds to a view of the segment 10 as viewed from the outside in the radial direction r (see FIG. 1). The area of the region surrounded by the outer shape of the segment 10 shown in FIG. 6 is larger than the area of the region surrounded by the outer shape of the segment 10 shown in FIG. This is because the structure 100 (see FIG. 1) in which the segments 10 are spread is formed into a semicylindrical shape.

  As shown in FIG. 6, the peripheral wall 10 a includes a first outer peripheral surface 11, a second outer peripheral surface 12, a third outer peripheral surface 13, and a fourth outer peripheral surface 14 having the same shape as in FIG. 4. Here, when the first outer peripheral surface 11 and the second outer peripheral surface 12 move symmetrically with respect to the symmetry axis S, they overlap each other. The segment 10 is provided with a blocking wall 10b so as to be continuous with the peripheral wall 10a.

  Next, the sectional shape of the segment 10 shown in FIG. 6 will be described with reference to FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. As shown in FIG. 7, the peripheral wall 10a is continuous with the closed wall 10b, and the inner wall 10c is also continuous with the closed wall 10b. As described above, the peripheral wall 10a, the blocking wall 10b, and the inner wall 10c are integrally formed by casting, for example. Further, the segment 10 is formed with an internal space IS partitioned by a peripheral wall 10a, a blocking wall 10b, and an inner wall 10c.

  Moreover, the through-hole 10h is provided in the surface corresponding to each edge | side in the external shape of the surrounding wall 10a, respectively. In addition, the through-hole 10h shown in FIG. 7 is the through-hole 10h provided in each surface included in the 1st outer peripheral surface 11, the 3rd outer peripheral surface 13, and the 4th outer peripheral surface 14 shown in FIG. . Similarly to the first outer peripheral surface 11, a through hole 10 h is provided in the second outer peripheral surface 12, which is not shown in FIG. 7.

  As shown in FIG. 7, the width in the circumferential direction θ on the closing side, which is the side where the closing wall 10b is provided in the segment 10, is larger than the width in the circumferential direction θ on the opening side, which is the opening end side. That is, the width in the circumferential direction θ of each of the first outer peripheral surface 11 (see FIG. 6) and the second outer peripheral surface 12 (see FIG. 6) is larger on the closing side than on the opening side. Therefore, it is possible to obtain the structure 100 (see FIG. 1) with the closed side facing outward (outward in the radial direction r).

  Next, how to use the through hole 10h shown in FIG. 7 and the like will be described with reference to FIG. FIG. 8 is an explanatory diagram showing an example of combining the segments 10. 8 corresponds to a view of the segment 10 as viewed from the front side (in the radial direction r), that is, from the opening end side, similarly to FIG. FIG. 8 shows an example in which a plurality of segments 10 are spread.

  As described above, the through holes 10h shown in FIG. 7 and the like are arranged so as to communicate with the through holes 10h of the adjacent segments 10. Therefore, the adjacent segments 10 can be joined together by fixing with the fasteners 20 through the communicating through holes 10h.

  Here, as described above, since the segment 10 is a hollow structure segment in which the internal space IS surrounded by the peripheral wall 10a and the like is formed, the weight can be reduced as compared with the solid structure segment. In addition, the operator can perform the fastening operation and the removal operation of the fastener 20 from the inside of the segment 10 using the internal space IS.

  As the fastener 20, for example, a bolt and a nut can be used. Here, the fastener 20 may be fastened for temporary fastening during assembly, and may be removed after the assembly is completed, or may be left fastened for final fastening.

  In addition, since the segment 10 has a plurality of hexagonal outlines connected in a row, when the segments 10 are spread, a compressive force is generated in a direction in which each side of the hexagon is pressed from the outside. That is, a so-called honeycomb structure can be formed by arranging a plurality of segments 10 side by side. Therefore, it can be said that the segment 10 is structurally stable. For this reason, even if it does not use the fastener 20, the position shift between the adjacent segments 10 can be suppressed. Therefore, since the load on the fastener 20 such as a bolt can be reduced, the thickness of the peripheral wall 10a itself can be easily reduced and the weight can be easily reduced. As a result, the cost can be reduced and the workability can be improved.

  Although FIG. 8 shows a case where the adjacent segments 10 are fastened, the three or more segments 10 are gathered together using a fastener 20 having a length for fastening the three or more segments 10 in a skewered manner. It is good also as fastening. Thereby, the integration of the three or more segments 10 can be achieved, and the positional deviation between the three or more segments 10 can be further suppressed. In this case, the through-hole 10h that penetrates the peripheral wall 10a only needs to be formed at a position where the fastener 20 can be inserted straight when three or more segments are adjacent to each other. The fastener 20 may be a PC steel material such as a PC steel wire, in addition to the bolts and nuts described above.

  Next, a modification of the segment 10 shown in FIG. 4 will be described with reference to FIG. FIG. 9 is an explanatory diagram showing a modified example of the segment 10. 9 corresponds to a view of the segment 10 as viewed from the front side (in the radial direction r), that is, from the opening end side, as in FIG.

  The segment 10 shown in FIG. 9 is different from the segment 10 shown in FIG. 4 in that the thick portion 16 is provided inside the corner portion surrounded by the peripheral wall 10a and the inner wall 10c. In this way, by thickening the inside of the corner portion surrounded by the peripheral wall 10a and the inner wall 10c, stress concentration at the corner portion can be prevented.

  Therefore, the strength of the segment 10 can be increased. In addition, in FIG. 9, although the case where all the corner parts were made thick was illustrated, it is good also as making only an arbitrary number of corner parts thick among all the corner parts.

  Next, the modification of the surrounding wall 10a in the segment 10 is demonstrated using FIG. FIG. 10 is an explanatory view showing a modification of the peripheral wall 10 a of the segment 10. FIG. 10 corresponds to a side view of the two segments 10 arranged so that the third outer peripheral surface 13 and the fourth outer peripheral surface 14 are in contact with each other when viewed from the axial direction z (see FIG. 1).

  As shown in FIG. 10, a cutout portion 17 cut out in the axial direction z is provided at a corner portion of the third outer peripheral surface 13 and the fourth outer peripheral surface 14 on the closing wall 10 b side. Further, a groove 18 that is cut out in the axial direction z is provided on the closed wall 10b side from the opening end 10s in the third outer peripheral surface 13 and the fourth outer peripheral surface 14. 10 illustrates a case where the cutout shape of the cutout portion 17 is a triangular prism shape and the cutout shape of the groove portion 18 is a quadrangular prism shape, but each cutout shape may be any shape.

  Thus, by providing the notch part 17 and the groove part 18, it becomes possible to arrange a water stop material etc. in the notched part. Therefore, it is possible to improve the water stoppage between the outer peripheral surfaces of the adjacent segments 10 and to prevent the filler such as mortar filled in the filling layer 500 from leaking out.

  10 exemplifies the case where the third outer peripheral surface 13 and the fourth outer peripheral surface 14 are provided with the notch 17 and the groove portion 18, but the first outer peripheral surface 11 and the second outer peripheral surface 12 are notched. 17 and the groove 18 may be provided. That is, at least a part of the outer peripheral surface of the segment 10 may be cut out in the circumferential direction. 10 illustrates the segment 10 including both the notch 17 and the groove 18, but one of the notch 17 and the groove 18 may be omitted from the segment 10.

  Next, a modified example of the inner wall 10c in the segment 10 will be described with reference to FIG. FIG. 11 is an explanatory view showing a modification of the inner wall 10 c of the segment 10. FIG. 11 corresponds to the cross-sectional view shown in FIG. Further, in FIG. 11, the description of the through hole 10h shown in FIG. 5 is omitted.

  As shown in FIG. 11, the inner wall 10c is provided with a rectangular opening 10ca penetrating the inner wall 10c. By providing the opening 10ca on the inner wall 10c, it is possible to reduce the weight of the segment 10, and the operator can put in his / her hand because of the internal space IS (see FIG. 8), and further has the opening 10ca. Therefore, it becomes possible to insert a rope, an instrument, etc., and to improve the transportability of the segment 10.

  11 illustrates the case where the opening 10ca is provided at a position closer to the closing wall 10b than the opening end 10s in the inner wall 10c, the position where the opening 10ca is provided may be a position closer to the opening end 10s of the peripheral wall 10a. Further, in FIG. 11, the rectangular opening 10ca is illustrated, but the shape of the opening 10ca may be a triangular shape, a circular shape, an elliptical shape, or the like. When there are a plurality of inner walls 10c, the openings 10ca may be provided on all the inner walls 10c, or the openings 10ca may be provided only on some of the inner walls 10c. Furthermore, it is good also as including opening 10ca of a different shape. In addition, in FIG. 11, although the case where the rectangular-shaped opening 10ca and the obstruction | occlusion wall 10b were separated was illustrated, it does not need to be separated.

  Next, a method for assembling the structure 100 shown in FIG. 1 will be described with reference to FIGS. FIGS. 12 and 13 are explanatory views 1 and 2 showing a method of assembling the structure 100. FIG. 14 is a flowchart showing the procedure of the assembling method.

  Here, in the assembling method shown in FIGS. 12 to 14, the arch-like structure is assembled by arranging the segments 10 in the circumferential direction θ, and then the assembled arch-like structure is assembled together with the structure first. This is a method of assembling the structure 100 by moving it until it comes into contact with the cylindrical structure side. In FIG. 12, the description of the front guide portion 301 (see FIG. 13) is omitted from the arch-shaped set of guide portions arranged along the inner wall of the existing lining layer 600 shown in FIG. is doing.

  As shown in FIG. 12, the assembly method of the structure 100 is performed from the one lower end F1 of the inner wall IW of the tunnel toward the other lower end F2 along the guide portion 300 for preventing shake or dropping (circumferential direction θ The arm portion 200 that rotates the segments 10 one by one is used. Further, an adjusting device 400 such as a hydraulic jack for adjusting the height of the first segment 10 is disposed at the other lower end F2. In addition, the guide part 300 and the guide part 301 are abbreviate | omitted, for example, it is good also as making the arch-like structures assembled by operation | movement of the arm part 200 contact.

  The arm part 200 turns around the central axis C of the tunnel. The arm unit 200 includes a holding mechanism that holds the segment 10 on the distal end side. The arm unit 200 moves in parallel along the central axis C. Here, the operations of the arm unit 200 and the adjusting device 400 are controlled by a control device (not shown). The operation of the arm unit 200 or the adjustment device 400 may be performed manually.

  In FIG. 12, the first segment 10 is shown as segment 10-1, and the second segment 10 is shown as segment 10-2. In FIG. 12, the segment 10-2 at one lower end F1 is indicated by a solid line, and the segment 10-2 rotated and moved to a position in contact with the segment 10-1 is indicated by a broken line.

  FIG. 13 includes a step of assembling the first arched structure R1 (see step S1 in FIG. 13), a step of assembling the second arched structure R2 (see step S2), and a second arched structure. Three steps of the step (see step S3) of bringing the body R2 into contact with the first arched structure R1 are shown.

  In the process of assembling the first arch-shaped structure R1, the first arch-shaped structure R1 is assembled by sequentially rotating the segments 10 with the arm part 200 while being guided by the one guide part 301. Here, one guide portion 301 is fixed to the inner wall IW of the tunnel. The other guide portion 300 may be fixed to the inner wall IW.

  Next, in the step of assembling the second arch-shaped structure R2, first, the other guide part 300 and the arm part 200 are positioned such that the second arch-shaped structure R2 does not contact the first arch-shaped structure R1. Translate to. Specifically, after the other guide portion 300 is moved by a predetermined amount in the direction D2 away from the first arch-like structure R1 in the axial direction z, the arm portion 200 is similarly moved by a predetermined amount in the direction D2. . Then, the second arch-like structure R2 is assembled by sequentially rotating and moving the segment 10 with the arm part 200 while being guided by the other guide part 300. In addition, when the other guide part 300 is being fixed to the inner wall IW in step S1, it is only necessary to release the fixing before moving in the direction D2 and re-fix after the moving.

  Further, as shown in FIG. 13, the segment 10 of the first arch-shaped structure R1 and the segment 10 of the second arch-shaped structure R2 are shifted in the circumferential direction θ so that the irregularities on the outer periphery mesh with each other. Be placed. Therefore, since the height of the first segment 10-1 differs between the first arch-shaped structure R1 and the second arch-shaped structure R2, the segment 10F (FIG. 23) in which the segment 10 is halved is used. The height of the segment 10-1 is adjusted by using each.

  Next, in the step of bringing the second arch-shaped structure R2 into contact with the first arch-shaped structure R1, the arm portion 200 is brought into contact with the first arch-shaped structure R1. Move to the position where you want to move. That is, the arm part 200 is moved by the predetermined amount described above in the direction D3 approaching the first arch-like structure R1 in the axial direction z. By repeating these steps, the structure 100 can be efficiently assembled.

  Next, the procedure of the method for assembling the structure 100 described with reference to FIGS. 12 and 13 will be described with reference to FIG. In the following description, the segment 10 is simply referred to as “segment”, and the arch-shaped structures such as the arch-shaped structures R1 and R2 are simply referred to as “arch”.

  As shown in FIG. 14, in the present assembly method, the first arch is assembled by rotating the segment 10 along one guide portion 301 (step S101). Then, the arm part 200 and the other guide part 300 are moved to a position where they do not interfere with the immediately preceding arch (step S102).

  Subsequently, the next arch is assembled by rotationally moving the segment along the other guide part 300 (step S103). Then, the arm unit 200 is moved until the next arch contacts the immediately preceding arch (step S104).

  Subsequently, it is determined whether or not the structure 100 is completed (step S105). If it is determined that the structure 100 is completed (step S105, Yes), the process is terminated. On the other hand, when it is determined that the structure 100 is not completed (No at Step S105), the processing procedure after Step S102 is repeated. Since the structure 100 completed in this way uses the above-described segment (segment 10), it is possible to suppress positional deviation between the adjacent segments 10.

  Note that, as described with reference to FIG. 8, when a plurality of segments 10 are fastened together, they may be fastened across a plurality of arch-like structures R.

  Next, a modified example of the method for assembling the structure 100 will be described with reference to FIGS. FIGS. 15 and 16 are explanatory views 1 and 2 showing a modification of the assembling method. FIG. 17 is a flowchart showing the procedure of a modification of the assembling method.

  As shown in FIG. 15, the assembling method according to the modified example is such that the segments 10 included in the second arch-shaped structure R2 are brought into contact with the first arch-shaped structure R1 one by one. Different from the assembly method shown in FIG. In addition, the segment 10-1 shown in FIG. 15 shall be the segment 10 which has already moved to the position which contacts 1st arch-like structure R1.

  When assembling the second arch-shaped structure R2, first, the arm portion 200 is translated to a position where the segment 10 that rotates in the circumferential direction θ does not come into contact with the first arch-shaped structure R1. Then, by turning the arm part 200 in the direction D4 in the circumferential direction θ, the segment 10-2 is rotationally moved to the “first position P1” next to the segment 10-1. Here, the rotational movement of the segment 10-2 is stopped immediately before contacting the segment 10-1. By stopping the rotational movement immediately before contact, it is easy to finely adjust the position of the segment 10-2 in the circumferential direction θ. That is, the unevenness on the outer periphery of the segment 10-2 in the second arch-shaped structure R2 can be easily meshed with the unevenness of the first arch-shaped structure R1. In addition, it is good also as rotating the segment 10-2 until it contacts the segment 10-1. In FIG. 15, the first position P1 is indicated by a broken line along the segment 10-2.

  Subsequently, the segment 10-2 at the first position P1 is moved in the direction D5 approaching the first arch-shaped structure R1 in the axial direction z, so that the segment 10-2 is in contact with the first arch-shaped structure R1. Move to a certain "second position P2". At this time, since the third outer peripheral surface 13 and the fourth outer peripheral surface 14 are flat, they can be easily slid even if they are brought into contact with each other.

  FIG. 16 shows the segment 10-2 moved to the second position P2. Thus, the structure 100 can be efficiently assembled also by bringing the segment 10 that has been rotated and moved into contact with the adjacent arch-shaped structure R one by one. In FIG. 16, the second position P2 is indicated by a broken line along the segment 10-2.

  Next, the procedure of a modified example of the assembly method described with reference to FIGS. 15 and 16 will be described with reference to FIG. In the following description, the segment 10 is simply referred to as “segment”, and the arch-shaped structures such as the arch-shaped structures R1 and R2 are simply referred to as “arch”.

  In the assembling method according to the modification, the first arch is assembled by rotating the segment (step S201). Subsequently, assembly of the next arch is started (step S202). First, the arm part 200 is moved to a position where it does not interfere with the immediately preceding arch (step S203). Then, the first segment is rotated (step S204).

  Then, the first segment is moved to the second position P2 in contact with the immediately preceding arch (first arch) (step S205). Subsequently, the segment is rotationally moved to the first position P1 next to the immediately preceding segment (step S206). Then, the segment is moved to the second position P2 in contact with the immediately preceding arch (first arch) (step S207).

  Subsequently, it is determined whether or not the “next arch” in step S202 is completed (step S208). If it is determined that the next arch is completed (step S208, Yes), the structure 100 is completed. It is determined whether or not (step S209). If it is determined that the next arch has not been completed (No at Step S208), the processes after Step S206 are repeated.

  And when it determines with the structure 100 having been completed in determination in step S209 (step S209, Yes), a process is complete | finished. In addition, when it determines with the structure 100 not being completed (step S209, No), the process after step S202 is repeated.

  Although FIG. 17 shows the case where the structure 100 is assembled with one arm part 200, a plurality of arm parts 200 may be used. For example, two arm portions 200 each responsible for half of one arch are used, and one arm portion 200 completes a half arch, and the other arm portion 200 completes the remaining half arch in a follow-up manner. It is good. By doing in this way, the time required to complete the structure 100 can be halved.

  12 to 17 illustrate the case where there are no facilities such as rails for rails or overhead wires in the tunnel, the structure 100 can be completed even when these facilities are present. For example, the movement in the axial direction z is facilitated by providing the arm unit 200 on a cart that can travel on rails. Alternatively, the arm unit 200 may be provided with a rotation shaft so that the arm unit 200 can be bent, and the structure 100 may be assembled while the arm unit 200 is appropriately bent so as to avoid obstacles such as overhead wires.

  When a plurality of sets of track rails are provided, the structure 100 may be assembled while changing the rail on which the above-described carriage travels according to the assembly location of the structure 100. For example, when there is a rail in operation among a plurality of sets of rails, the structure 100 can be assembled while suppressing the influence on the rail in operation.

  12 to 17 show the case where the respective segments are sequentially rotated from one lower end to the other lower end of the inner wall of the tunnel. However, the order in which the segments are rotationally moved is appropriately changed. be able to. For example, the direction of rotational movement is reversed in the middle, the range of rotational movement is divided into multiple sections, the construction order of each section is changed to an arbitrary order, and the direction of rotational movement in each section is changed appropriately. It is good also as doing.

  By the way, the segment 10 which has the outline of the shape which arranged the some hexagon in a line so that the sides of adjacent hexagons may overlap has been demonstrated so far. However, the present invention is not limited to this, and the segment 10 may have another shape as long as the contour shape is a concave polygon and a plurality of segments 10 can be spread. For this reason, below, the variation of a concave polygon is demonstrated using FIGS. 18 to 24 are explanatory views showing variations 1 to 7 of the concave polygon.

  First, variation 1 of the concave polygon will be described with reference to FIG. The segment 10A shown in FIG. 18 has a concave polygonal shape having six sides. As shown in FIG. 18, the first outer peripheral surface 11 has one concave portion 10ab formed with two sides, and the second outer peripheral surface 12 has one convex portion 10aa formed with two sides. have.

  Moreover, the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 are a shape which mutually overlaps, when it moves in parallel. Here, the first outer peripheral surface 11 and the second outer peripheral surface 12 are exchanged so that the first outer peripheral surface 11 has one convex portion and the second outer peripheral surface 12 has one concave portion. Also good. Note that the first outer peripheral surface 11 and the second outer peripheral surface 12 may be interchanged in other variations shown in FIG.

  The description of FIG. 18 continues. The third outer peripheral surface 13 and the fourth outer peripheral surface 14 that connect one ends of the first outer peripheral surface 11 and the second outer peripheral surface 12 can be flat as shown by a solid line in FIG. Here, the concave portion 13a may be provided on the third outer peripheral surface 13, and the convex portion 14a having a shape engaging with the concave portion 13a may be provided on the fourth outer peripheral surface 14 (see the broken line in FIG. 18). Here, the third outer peripheral surface 13 and the fourth outer peripheral surface 14 may be interchanged, and a convex portion may be provided on the third outer peripheral surface 13, and a concave portion may be provided on the fourth outer peripheral surface 14.

  In addition, also in each variation shown in FIGS. 19-24, it is good also as providing the recessed part or convex part which mutually meshes with the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14. FIG. The same applies to the segment 10 shown in FIG.

  Further, a plurality of concave polygonal shapes having six sides shown in FIG. 18 may be formed continuously on the third outer peripheral surface 13 or the fourth outer peripheral surface 14 side. Further, when a plurality of the outer peripheral surfaces are made continuous, the first outer peripheral surface 11 and the second outer peripheral surface 12 may be alternately reversed. The same applies to the variations shown in FIGS.

  Further, when the third outer peripheral surface 13 and the fourth outer peripheral surface 14 in the segment 10A shown in FIG. 18 are not flat (see the broken line in FIG. 18), the assembly method shown in FIGS. 15 and 16 is as follows. You can do it. That is, the position where one convex portion 14a of the third outer peripheral surface 13 and the fourth outer peripheral surface 14 is in contact with a position other than the other concave portion 13a is defined as a first position P1 (see FIG. 15). What is necessary is just to move the segment 10A to the 2nd position P2 (refer FIG. 16) by moving the arm part 200 to the position where 14a and the recessed part 13a fit.

  Next, variation 2 of the concave polygon will be described with reference to FIG. The segment 10B shown in FIG. 19 is different from the segment 10A shown in FIG. 18 in that the concave portion 10ab of the first outer peripheral surface 11 and the convex portion 10aa of the second outer peripheral surface 12 are each formed by three sides.

  The first outer peripheral surface 11 and the second outer peripheral surface 12 have shapes that overlap each other when translated. Moreover, the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14 which connect the end of the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 can be made flat as shown, for example in FIG. .

  Next, variation 3 of the concave polygon will be described with reference to FIG. The segment 10C shown in FIG. 20 is different from the segment 10A shown in FIG. 18 in that the first outer peripheral surface 11 has a rectangular concave portion 10ab and the second outer peripheral surface 12 has a rectangular convex portion 10aa. Different.

  The first outer peripheral surface 11 and the second outer peripheral surface 12 have shapes that overlap each other when translated. Moreover, the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14 which connect the ends of the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 can be made flat as shown, for example in FIG. .

  Next, variation 4 of the concave polygon will be described with reference to FIG. The segment 10D shown in FIG. 21 is different from the segment 10A in that the shape of the segment 10A shown in FIG. 18 is repeated 1.5 times. Hereinafter, description of the convex portion 10aa and the concave portion 10ab is omitted by illustrating the reference numerals.

  As shown in FIG. 21, the first outer peripheral surface 11 and the second outer peripheral surface 12 have shapes that overlap each other when translated. Moreover, the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14 which connect the ends of the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 can be made flat as shown, for example in FIG. .

  Next, variation 5 of the concave polygon will be described with reference to FIG. A segment 10E shown in FIG. 22 is different from the segment 10A in that the segment 10A shown in FIG.

  As shown in FIG. 22, the first outer peripheral surface 11 and the second outer peripheral surface 12 have shapes that overlap each other when translated. Moreover, the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14 which connect the ends of the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 can be made flat as shown, for example in FIG. .

  Next, variation 6 of the concave polygon will be described with reference to FIG. A segment 10F illustrated in FIG. 23 has a shape obtained by dividing the segment 10 illustrated in FIG. 6 and the like into two equal parts in parallel with the third outer peripheral surface 13 or the fourth outer peripheral surface 14. When the two segments 10F are arranged so that the fourth outer peripheral surfaces 14 are in contact with each other, the shape is the same as that of the segment 10 (see FIG. 6).

  As shown in FIG. 23, the first outer peripheral surface 11 and the second outer peripheral surface 12 have shapes that overlap each other when they are moved symmetrically. Moreover, the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14 which connect the ends of the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 can be made flat as shown, for example in FIG. .

  Next, variation 7 of the concave polygon will be described with reference to FIG. The segment 10G shown in FIG. 24 has a shape in which three hexagons are arranged so that the sides of adjacent hexagons overlap each other. Here, the segment 10G shown in FIG. 24 is different from the segment 10 shown in FIG. 6 and the like in that the three hexagons are not arranged in a line.

  That is, the segment 10G has a shape in which two hexagons are arranged so that one side of adjacent hexagons overlaps, and a third hexagon is arranged next to the side aligned in a row. In FIG. 24, one side of the hexagon that overlaps is indicated by a broken line for reference.

  The first outer peripheral surface 11 and the second outer peripheral surface 12 have shapes that overlap each other when translated. Moreover, the 3rd outer peripheral surface 13 and the 4th outer peripheral surface 14 which connect the ends of the 1st outer peripheral surface 11 and the 2nd outer peripheral surface 12 are formed in 2 sides, as shown in FIG. 24, for example. It can be set as one convex part 10aa.

  Thus, although the variation of the concave polygon has been described using FIGS. 18 to 24, these variations are only a part of many variations. That is, a concave polygon that can fit a plurality of segments 10 is sufficient.

  Next, the other modification example 1 of the segment 10 shown in FIGS. 2-7 is demonstrated using FIG. The segment 10J shown in FIG. 25 includes a cylindrical peripheral wall 10a. The outer shape of the peripheral wall 10a includes the outline of a shape in which three hexagons are arranged in a row so that the sides of adjacent hexagons overlap each other as in the segment 10 shown in FIG. The peripheral wall 10a includes a first side wall 101 adjacent to a convex part 10aa projecting toward the outer peripheral side and a concave part 10ab recessed toward the inner peripheral side, and a second side wall 102 obtained by symmetrically moving the first side wall 101. And a flat third side wall 103 that connects one ends of the first side wall 101 and the second side wall 102, and a flat fourth side wall 104 that connects the other ends. The first side wall 101 has a first outer peripheral surface 11 (see FIG. 4) that is an outer wall surface of the first side wall 101, and the second side wall 102 is a first outer wall surface of the second side wall 102. 2 has an outer peripheral surface 12 (see FIG. 4), and the third side wall 103 has a third outer peripheral surface 13 (see FIG. 4), which is an outer wall surface of the third side wall 103, and has a fourth side wall. 104 has the 4th outer peripheral surface 14 (refer FIG. 4) which is an outer wall surface of the 4th side wall 104. FIG.

  Since the outer shape of the cylindrical peripheral wall 10a includes three hexagonal contours connected in a row, the segment 10J overlaps with each other when the first side wall 101 and the second side wall 102 are moved symmetrically. , 102 are opposed to each other, and the concave portions 10ab are opposed to each other. For this reason, a honeycomb structure can be formed by arranging a plurality of segments 10J side by side. Therefore, it is possible to provide the segment 10J which is structurally stable.

  Further, the segment 10J includes a first inner wall 111 that connects the convex portions 10aa of the first and second side walls 101, 102 facing each other. For this reason, the segment 10J is spread so that the first and second side walls 101, 102 are along the circumferential direction θ of the arch-shaped structure (see FIG. 1), and external force acts on the arch-shaped structure from above, When a compressive force is applied in a direction in which the third and fourth side walls 103 and 104 are brought closer to each segment 10J, the first inner wall 111 is deformed so that the convex portions 10aa facing each other are moved away from each other. Resist. Therefore, the deformation of the segment 10J can be suppressed, and the honeycomb structure can be easily held.

  Specifically, when a compressive force is applied to each segment 10J in the circumferential direction θ, the third and third directions are such that the peaks corresponding to the convex portions 10aa move away from each other and the valleys corresponding to the concave portions 10ab approach each other. Each of the segments 10J tends to deform in a direction in which the four side walls 103 and 104 approach each other. In the segment 10J, since the first inner wall 111 that connects the convex portions 10aa is provided, it is possible to resist deformation in a direction in which the mountains are away from each other. In the segment 10J, since the inner wall 10c that connects the recesses 10ab is further provided, it is possible to resist deformation in a direction in which the valleys approach each other. Therefore, the deformation of the segment 10J can be further suppressed.

  In the segment 10J, the first inner wall 111 is provided so as to connect all the opposing convex portions 10aa of the first and second side walls 101, 102, but some of the opposing convex portions 10aa are provided. You may provide so that it may connect. Further, in the segment 10J, the first inner wall 111 is formed so as to connect the opposing convex portions 10aa to each other and to be connected to the blocking wall 10b. However, a space is formed between the first inner wall 111 and the blocking wall 10b. It is good also as providing. In this way, the weight of the segment 10J can be reduced.

  Next, a modification of the first inner wall 111 shown in FIG. 25 will be described with reference to FIG. As shown in FIG. 26, the first inner wall 111A according to the modified example is different from the first inner wall 111 in that the first inner wall 111 (see FIG. 25) is cut out from the opening side of the segment 10J. Different. Specifically, the first inner wall 111A has a shape in which the protruding portion 111a formed so as to be continuous with the first side wall 101, the second side wall 102, and the blocking wall 10b is left out. By doing in this way, weight reduction of the segment 10J can be achieved rather than the case where the 1st inner wall 111 is provided, suppressing a deformation | transformation of the segment 10J.

  Next, another modification 2 of the segment 10 will be described with reference to FIG. Similarly to the segment 10J shown in FIG. 25, the segment 10K shown in FIG. 27 also has a cylindrical peripheral wall 10a, and the external shape of the peripheral wall 10a is such that three hexagons overlap each other on one side of adjacent hexagons. Includes contours arranged in a line. The peripheral wall 10a includes a first side wall 101 adjacent to a convex part 10aa projecting toward the outer peripheral side and a concave part 10ab recessed toward the inner peripheral side, and a second side wall 102 obtained by symmetrically moving the first side wall 101. And a flat third side wall 103 that connects one ends of the first side wall 101 and the second side wall 102, and a flat fourth side wall 104 that connects the other ends.

  Further, the segment 10K includes a second inner wall 112 that connects the third and fourth side walls 103 and 104. Therefore, in the same way as the segment 10J shown in FIG. 25, when a compressive force acts in the direction in which the third and fourth side walls 103 and 104 are brought closer to each segment 10K in the circumferential direction θ, The two inner walls 112 resist the deformation that the third and fourth side walls 103, 104 are about to approach. Therefore, deformation of the segment 10K can be suppressed, and the honeycomb structure can be easily held.

  Specifically, when a compressive force is applied to each segment 10K in the circumferential direction θ, the third and second directions are such that the peaks corresponding to the convex portions 10aa move away from each other and the valleys corresponding to the concave portions 10ab approach each other. Each of the segments 10K tends to be deformed in a direction in which the four side walls 103 and 104 approach each other. In the segment 10K, the second inner wall 112 that connects the third and fourth side walls 103 and 104 is provided, so that the third and fourth side walls 103 and 104 are resistant to deformation in a direction in which the third and fourth side walls 103 and 104 approach each other. Can do. In the segment 10K, since the first inner wall 111 that connects the convex portions 10aa is further provided, it is possible to resist deformation in a direction in which the mountains are away from each other. In the segment 10K, since the inner wall 10c that connects the recesses 10ab is further provided, it is possible to resist deformation in a direction in which the valleys approach each other. Therefore, the deformation of the segment 10K can be further suppressed.

  In the segment 10K, the second inner wall 112 is formed so as to connect the third and fourth side walls 103 and 104 and to be connected to the blocking wall 10b (see FIG. 25). It is good also as providing space between the obstruction | occlusion wall 10b. By doing so, the weight of the segment 10K can be reduced.

  Next, another modification 3 of the segment 10 will be described with reference to FIG. Similarly to the segment 10K shown in FIG. 27, the segment 10L shown in FIG. 28 includes a cylindrical peripheral wall 10a, and the outer shape of the peripheral wall 10a is such that three hexagons overlap each other on one side of adjacent hexagons. Includes contours arranged in a line. The peripheral wall 10a includes a first side wall 101 adjacent to a convex part 10aa projecting toward the outer peripheral side and a concave part 10ab recessed toward the inner peripheral side, and a second side wall 102 obtained by symmetrically moving the first side wall 101. And a flat third side wall 103 that connects one ends of the first side wall 101 and the second side wall 102, and a flat fourth side wall 104 that connects the other ends.

  Further, the segment 10L has a protruding portion 115 that protrudes toward the inner peripheral side from the convex portion 10aa of the first and second side walls 101 and 102 so as to cover a part of the opening 10az of the cylindrical peripheral wall 10a. It has. The overhang portion 115 includes a portion overhanging from the convex portion 10aa so as to close the opening side of the inner angle a1 of the convex portion 10aa. Therefore, similarly to the segment 10K shown in FIG. 27, when a compressive force is applied in a direction in which the third and fourth side walls 103, 104 are brought closer to each segment 10L in the circumferential direction θ, the tension is increased. The protruding portion 115 resists deformation in which the inner angle a1 of the convex portion 10aa tends to narrow. Therefore, the deformation of the segment 10L can be suppressed, and the honeycomb structure can be easily held.

  Specifically, when a compressive force is applied to each segment 10L in the circumferential direction θ, the third and third directions are such that the peaks corresponding to the convex portions 10aa move away from each other and the valleys corresponding to the concave portions 10ab approach each other. Each of the segments 10L tends to deform in a direction in which the four side walls 103 and 104 approach each other. Moreover, in each hexagon of the three hexagons connected in a row forming the outer shape of the peripheral wall 10a, the inner angle a1 (corresponding to the inner angle of the hexagon) of each surface 10aas of the convex portion 10aa is directed to narrow. The inner angle a2 excluding the inner angle a1 tends to be deformed in a direction in which the inner angle a2 tends to widen. In the segment 10L, since the overhanging portion 115 is provided so as to close the opening side of the inner angle a1 of the convex portion 10aa, it is possible to resist the deformation in which the inner angle a1 is narrowed. In the segment 10L, the overhanging portion 115 further extends from the opening end 10s of the first, second, third, and fourth side walls 101, 102, 103, 104 and the inner wall 10c to the inside of each hexagon. Since it is overhanging, it is possible to resist the deformation in which all the inner angles a1 of the hexagon are to be narrowed and the deformation in which all the inner angles a2 are to be widened. In the segment 10L, since the first inner wall 111 that connects the convex portions 10aa is further provided, it is possible to resist deformation in a direction in which the mountains are away from each other. Therefore, the deformation of the segment 10L can be further suppressed.

  Next, the cross-sectional shape of the segment 10L shown in FIG. 28 will be described with reference to FIG. 29 is a cross-sectional view taken along line XXIX-XXIX in FIG. As shown in FIG. 29, an example of the thickness of the overhanging portion 115 is substantially the same as or thinner than the thickness of the blocking wall 10b and the first inner wall 111, but can be an arbitrary thickness. In the segment 10L, the overhanging portions 115 are provided at all the inner angles a1 and a2, but may be provided at any of the inner angles a1 and a2.

  Next, a first modification of the overhanging portion 115 shown in FIG. 28 will be described with reference to FIG. The segment 10LA shown in FIG. 30 is similar to the segment 10 shown in FIG. 4 in that the segment 10 shown in FIG. 4 is provided with an overhang 115A having a shape different from the overhang 115 shown in FIG. This is different from the segment 10L shown in FIG.

  As shown in FIG. 30, the projecting portion 115A includes a portion projecting from the convex portion 10aa so as to block the opening side of the inner angle a1 of the convex portion 10aa in a triangular shape. For this reason, the shape of the opening part which is not covered with the overhang | projection part 115A is a rectangular shape. By doing in this way, the deformation | transformation which the internal angle a1 of each surface 10aas of convex part 10aa tends to narrow can be suppressed further.

  Next, the cross-sectional shape of the segment 10LA shown in FIG. 30 will be described with reference to FIG. 31 is a cross-sectional view taken along line XXXI-XXXI in FIG. FIG. 31 shows the end face of the overhanging portion 115A. The shape in which the projecting portion 115A covers a part of the opening can be an arbitrary shape regardless of the shape shown in FIGS. For example, the inner peripheral side of the overhang portion 115A may be curved.

  Next, a second modification of the overhanging portion 115 shown in FIG. 28 will be described with reference to FIG. The segment 10LB shown in FIG. 32 is different from the segment 10LA shown in FIG. 30 in that it has a protruding portion 115B having a shape different from that of the protruding portion 115A shown in FIG.

  As shown in FIG. 32, the protruding portion 115B includes a portion protruding from the convex portion 10aa so as to close the opening side of the inner angle a1 of the convex portion 10aa. The overhanging portion 115B is formed so as to connect the opening sides of the convex portions 10aa facing each other.

  Specifically, when a compressive force is applied to each segment 10LB in the circumferential direction θ, the third and third directions are such that the peaks corresponding to the convex portions 10aa move away from each other and the valleys corresponding to the concave portions 10ab approach each other. The segment 10LB tends to deform in a direction in which the four side walls 103 and 104 approach each other. Further, the inner angle a1 of the convex portion 10aa tends to be deformed in a direction to be narrowed, and the inner angle a2 excluding the inner angle a1 is to be deformed in a direction to be widened. In the segment 10LB, since the overhanging portion 115B is provided so as to close the opening side of the inner angle a1 of the convex portion 10aa, it is possible to resist the deformation in which the inner angle a1 is narrowed. Further, in the segment 10LB, the overhanging portion 115B is formed so as to connect the opening sides of the opposing convex portions 10aa, so that it can resist deformation in a direction in which the mountains are away from each other. Therefore, deformation of the segment 10LB can be suppressed.

  Next, the cross-sectional shape of the segment 10LB shown in FIG. 32 will be described with reference to FIG. 33 is a cross-sectional view taken along line XXXIII-XXXIII in FIG. As shown in FIG. 33, the overhanging portion 115B has a convex cross-sectional shape. By doing in this way, the cross-sectional performance of the overhang | projection part 115B can be improved, and a deformation | transformation of the segment 10LB can be suppressed.

  Next, a modified example of the through hole 10h shown in FIGS. 5 and 7 will be described with reference to FIGS. FIG. 34 shows a case where a plurality of through holes 10h penetrating each surface of the first and second side walls 101 and 102 are arranged along the radial direction r. By doing in this way, adjacent segment 10M can be connected more firmly.

  FIG. 35 shows a case where two through holes 10h are arranged on each surface of the first and second side walls 101, 102 so as to be close to the opening side of the segment 10MA. By doing in this way, adjacent segment 10MA can be connected by the opening side which deform | transforms more easily than the obstruction | occlusion wall 10b side, and a deformation | transformation of segment 10MA can be suppressed further. Further, by providing a plurality of through holes 10h on each surface, adjacent segments 10MA can be more firmly connected. Note that three or more through holes 10h may be arranged on each surface.

  FIG. 36 shows a case where the through holes 10h shown in FIG. 35 are arranged so as to be close to the connecting portions (bent portions) of the respective surfaces. By doing in this way, segments 10MB can be connected by the connection part in which the displacement amount of a deformation | transformation tends to become large, and a deformation | transformation of the segment 10MB can be suppressed further.

  Next, a modified example of the opening 10ca shown in FIG. 11 will be described with reference to FIGS. 37 and 38, the opening 10ca provided in the inner wall 10c that connects the recesses 10ab in FIG. 11 is provided in the peripheral wall 10a and the like.

  FIG. 37 shows a case where one opening 10ah brought close to the blocking wall 10b is provided on each surface of the peripheral wall 10a. By doing in this way, the deformation | transformation of the opening side which is easy to deform | transform rather than the obstruction | occlusion wall 10b side can be suppressed, aiming at weight reduction of the segment 10N. Although FIG. 37 shows the rectangular opening 10ah, the shape of the opening 10ah may be other shapes such as a circle or an ellipse.

  FIG. 38 shows a case where two openings 10ah are arranged along the radial direction r on each surface of the peripheral wall 10a. Thus, it is good also as providing several opening 10ah in each surface of the surrounding wall 10a. In the segment 10NA shown in FIG. 38, an opening 10bh is provided in the blocking wall 10b at a position that avoids the first inner wall 111. Thus, it is good also as providing opening 10bh also in the obstruction | occlusion wall 10b. Thus, by reducing the thickness of the peripheral wall 10a and the blocking wall 10b, the weight of the segment 10NA can be reduced. The number of openings 10ah arranged on each surface of the peripheral wall 10a may be three or more, and the openings 10ah may be arranged in a matrix.

  In FIGS. 37 and 38, the opening 10ah and the opening 10bh penetrating the peripheral wall 10a and the blocking wall 10b are shown, but the thickness of the wall may be reduced. By doing so, the weight of the segment can be reduced.

  In addition, in FIGS. 25 to 33, the case where a compressive force is applied to each segment in the circumferential direction θ has been described, but even if a tensile force is applied to each segment, the first inner wall 111. The second inner wall 112 or the overhanging portion 115 can resist such tensile force. Therefore, the deformation of the segment accompanying the tensile force can be suppressed.

  In addition, although the hexagon in the above-described embodiment is preferably a regular hexagon, a pair of opposing sides may be longer or shorter than the other sides. In the above-described embodiment, the arch-like tunnel-like structure 1 and the structure 100 are shown. However, the tunnel-like structure 1 and the structure 100 may be cylindrical. Moreover, it is good also as using the structure 100 for reinforcement of these pipes, for example by arrange | positioning on the outer peripheral side, such as a water pipe and a sewer pipe.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative examples shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

  DESCRIPTION OF SYMBOLS 1 Tunnel-like structure, 10 segment, 10a peripheral wall, 10aa convex part, 10ab concave part, 10b obstruction | occlusion wall, 10c inner wall, 10h through-hole, 10s opening end, 11 1st outer peripheral surface, 12 2nd outer peripheral surface, 13 1st 3 outer peripheral surface, 14 fourth outer peripheral surface, 16 thick portion, 17 notch portion, 18 groove portion, 20 fastener, 100 structure, 101 first side wall, 102 second side wall, 103 third side wall, 104 fourth side wall, 111 first inner wall, 112 second inner wall, 115 overhang part, 200 arm part, 300, 301 guide part, 400 adjusting device, 500 filling layer, 600 existing lining layer, C central axis , P1 first position, P2 second position, S symmetry axis, θ circumferential direction, r radial direction, z axis direction.

Claims (17)

An outer peripheral surface having a concave polygonal outer shape,
The outer peripheral surface includes a first outer peripheral surface and a second outer peripheral surface that overlap each other when moved symmetrically or translated,
The first outer peripheral surface includes at least one convex portion protruding toward the outer peripheral side,
The second outer peripheral surface is a segment including at least one concave portion recessed toward the inner peripheral side. The first outer peripheral surface includes at least one concave portion adjacent to the at least one convex portion and recessed toward the inner peripheral side,
2. The segment according to claim 1, wherein the second outer peripheral surface includes at least one convex portion that is adjacent to the at least one concave portion and protrudes toward the outer peripheral side.   The segment according to claim 2, wherein the outer shape includes a contour of a shape in which a plurality of hexagons are arranged in a row so that sides of adjacent hexagons overlap each other.   The said outer peripheral surface is a segment as described in any one of Claims 1-3 containing the groove part which notches at least one part of outer periphery in the circumferential direction.   The outer peripheral surface includes a flat third outer peripheral surface that connects one ends of the first outer peripheral surface and the second outer peripheral surface, and a flat fourth outer peripheral surface that connects the other ends. The segment as described in any one of 1-4.   The circumferential width of each of the first outer circumferential surface and the second outer circumferential surface is larger than the circumferential width of each of the third outer circumferential surface and the fourth outer circumferential surface. The stated segment.   The segment according to any one of claims 1 to 6, wherein the outer peripheral surface is an outer wall surface of a cylindrical peripheral wall.   The segment of Claim 7 provided with the obstruction | occlusion wall which obstruct | occludes one opening of the said cylindrical surrounding wall.   9. The segment according to claim 8, wherein a width of each of the first outer peripheral surface and the second outer peripheral surface in the circumferential direction is larger on the closing side than on the opening side.   The segment of Claim 8 or 9 provided with the inner wall which connects the said recessed parts which oppose.   The said surrounding wall is a segment as described in any one of Claims 7-10 containing the through-hole which penetrates the said outer peripheral surface. A plurality of segments according to any one of claims 1 to 11, comprising:
A structure in which a plurality of the segments are arranged along the inner wall of the tunnel. Using a plurality of segments and an arm portion that rotates and moves each of the segments along the inner wall of the tunnel,
A first assembly step of assembling a first arched structure by rotating each of the segments;
A second assembly step of assembling a second arcuate structure by rotationally moving each of the segments;
The second assembly step includes a step of moving the arm portion to a position where the second arch-like structure does not interfere with the first arch-like structure;
Rotating the second segment to a first position next to the first segment that has just been rotated and brought into contact with the first arcuate structure;
Moving the arm portion to move the second segment from the first position to a second position in contact with the first arched structure. Using a plurality of segments and an arm portion that rotates and moves each of the segments along the inner wall of the tunnel,
Assembling a first arched structure by rotating each of the segments;
Moving the arm part to a position where it does not interfere with the first arched structure;
Assembling a second arched structure by rotating each of the segments;
Bringing the second arched structure into contact with the first arched structure. With a cylindrical wall,
The outer shape of the peripheral wall includes a plurality of hexagons, the outline of the shape arranged in a row so that one side of adjacent hexagons overlap each other,
The peripheral wall includes a first side wall adjacent to a convex portion projecting toward the outer peripheral side and a concave portion recessed toward the inner peripheral side, a second side wall obtained by symmetrically moving the first side wall, and the first side wall. A flat third side wall connecting one end of the first side wall and the second side wall, and a flat fourth side wall connecting the other end,
The segment further comprising a first inner wall connecting the convex portions facing each other on the first side wall and the second side wall. With a cylindrical wall,
The outer shape of the peripheral wall includes a plurality of hexagons, the outline of the shape arranged in a row so that one side of adjacent hexagons overlap each other,
The peripheral wall includes a first side wall adjacent to a convex portion projecting toward the outer peripheral side and a concave portion recessed toward the inner peripheral side, a second side wall obtained by symmetrically moving the first side wall, and the first side wall. A flat third side wall connecting one end of the first side wall and the second side wall, and a flat fourth side wall connecting the other end,
The segment further comprising a second inner wall connecting the third side wall and the fourth side wall. With a cylindrical wall,
The outer shape of the peripheral wall includes a plurality of hexagons, the outline of the shape arranged in a row so that one side of adjacent hexagons overlap each other,
The peripheral wall includes a first side wall adjacent to a convex portion projecting toward the outer peripheral side and a concave portion recessed toward the inner peripheral side, a second side wall obtained by symmetrically moving the first side wall, and the first side wall. A flat third side wall connecting one end of the first side wall and the second side wall, and a flat fourth side wall connecting the other end,
A segment further comprising an overhanging portion projecting from the convex portion of the first side wall and the second side wall toward the inner peripheral side so as to cover a part of one opening of the cylindrical peripheral wall.