JP2021080754A - Pipe conduit and method for assembling pipe conduit - Google Patents

Abstract

To provide a pipe conduit and a method for assembling the pipe conduit, that allows cables to be inserted through one type of segment while having a zigzag arrangement.SOLUTION: A sewer conduit is constructed into a cylindrical shape by arranging segments in a zigzag manner in a circumferential direction and an axial direction. The sewer conduit is equipped with A-type segment 3 that is arranged in a zigzag pattern, B1 type segments 4A, 4B and B2 type segments 5A, 5B, that are arranged alternately in a left-right direction and have different circumferential lengths, and a K-type segment 6 that is fitted in a gap between the B1 type segments 4A, 4B and the B2 type segments 5A, 5B. The B1 type segments 4A, 4B having a length L1 and the B2 type segments 5A, 5B having a length L2 are arranged alternately in the left-right direction with respect to a difference (L2-L1) in the circumferential position of the A-type segment 3 before and after the zigzag arrangement. An insertion pipe 14 provided in the K-type segment 6 is fitted into a recess part 16 of the K-type segment 6 adjacent to a protrusion part 14a at time of fitting, and the K-type segment 6 and the insertion pipe 14 are linearly connected in the axial direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pipe and a method of assembling a pipe which is installed above ground or underground and can be provided with an insertion pipe in which cables such as an optical fiber cable and an electric wire cable can be laid.

Conventionally, public enterprises provide a space such as a sewer pipe as a space for laying an optical fiber cable or an electric wire cable, and obtain a rent from a telecommunications carrier to cover the cost of a sewer maintenance project. Similar efforts are being made in road tunnels and the like. Based on this, similar attempts are being considered in electric power tunnels and utility tunnels.
For example, in sewer pipes, tunnels, etc., a part of the internal space is provided to the telecommunications carrier, so when laying optical fiber cables, etc., anchors are driven into the ceiling to hang the cables. Especially inside the sewer pipe, the cable is laid in a bad environment because of the flow of sewage and bad odor. For this reason, it is difficult to lay cables in sewer pipes with a large flow rate, and telecommunications carriers are shunned in terms of maintenance.

On the other hand, in the sewer pipe described in Patent Document 1, for example, a cable accommodating space is provided inside the sewer pipe by providing a plurality of cable layer passage holes extending along the pipe axis direction in the pipe wall body of the pipe. I try not to.
However, the sewer pipe described in Patent Document 1 is an extruded pipe made of synthetic resin, and has a basic drawback that it is not strong enough to withstand the weight of a vehicle that is buried in the ground and travels on the ground or on the road. is there. Moreover, a large number of holes for passing cable layers are arranged in the pipe wall along the circumferential direction of the pipe, which makes the processing complicated and the manufacturing cost is high.

Further, the sewerage concrete pipe described in Patent Document 2 forms a cylindrical sewage flow pipe in the center of a substantially prismatic concrete wall. Moreover, a cable laying hole for laying cables such as an optical fiber cable and an electric wire cable is formed in a thick corner of a concrete wall.
Therefore, the concrete pipe described in Patent Document 2 has high strength and can withstand the weight of a vehicle that is buried in the ground and travels on the ground or on the road. Since the cable laying hole is formed, there is a drawback that the concrete weight is large and the cost is high. Moreover, the cable laying holes must be formed in the thick corners, and the construction cost is high.

Further, the sewer pipe 100 shown in FIG. 8 is formed of a pipe pipe formed in a cylindrical shape by arranging substantially arcuate slab-shaped segments in a staggered pattern. Due to the staggered set of segments, the K-shaped segment to be fitted at the end of the segment ring also had to be mounted at different positions in the circumferential direction.
In the case of the sewer pipe 100 shown in FIG. 8, a small trapezoidal K-shaped segment 103 is fitted between the B1 type segment 101 and the B2 type segment 102, and the segment ring 105 is constructed by being connected by the bolt box 104. There is. A cable 107 such as an optical fiber cable or an electric wire cable is inserted into a linear insertion pipe 106 provided in a B2 type segment 102 arranged so as to be displaced in the axial direction of the sewer pipe 100.

Japanese Unexamined Patent Publication No. 2001-220806 Jikkenhei 2-121686

However, in the staggered sewer pipe 100, it is necessary to bury the insertion pipe 106 at a different position of each B2 type segment 102 displaced in the circumferential direction and arrange it in a straight line. Therefore, it is necessary to manufacture two types of B2 type segments 102 in which the embedding position of the insertion pipe 106 is shifted, which is troublesome and costly. Moreover, in order to linearly connect the insertion pipe 106 through which the cable 107 is inserted, the alignment of each B2 type segment 102 must be performed with high accuracy. In addition, the mounting position of the B2 type segment 102 may be mistaken during assembly.

The present invention has been made in view of such a problem, and provides a pipe and a method for assembling a pipe in which a cable can be inserted by using one type of segment in a staggered arrangement. The purpose.

The conduit according to the present invention is a tubular conduit constructed by arranging a plurality of segments in a staggered manner in the circumferential direction and the axial direction, and is arranged alternately in the left-right direction along the axial direction and has different circumferential lengths. It includes a first segment and a second segment, and a third segment fitted in the gap between the left and right first segment and the second segment, and the third segment is linear in the axial direction without shifting the position in the circumferential direction. It is characterized in that it is connected to.
According to the present invention, even if a pipe is constructed by staggering the segments, a single type of third segment fitted in the gap between the first segment and the second segment is linearly arranged in the axial direction. Since it can be arranged, the insertion tube, the hole, and the like can be arranged linearly through the third segment.

Further, it is preferable that an insertion pipe for laying a cable embedded in the third segment is further provided, and the insertion pipe is linearly connected in the axial direction without shifting the position in the circumferential direction.
The cable can be inserted smoothly through the insertion tube.

Further, the insertion pipe embedded in the third segment may have one end protruding from one end face of the third segment and retracted inside the other end face facing one end face.
When the third segment is fitted into the gap between the first segment and the second segment, the insertion pipes can be connected to each other by fitting the protrusion at one end of the insertion pipe into the recess at the other end.

Further, the insertion pipe may have a stopper fixed to a concrete-filled portion in the third segment.
By fixing the stopper to the insertion tube, it is possible to prevent the insertion tube from coming off during the manufacture of the third segment.

Further, in the third segment, two joint portions may be provided at the axial connection portion, and an insertion pipe may be arranged between the two joint portions.
By arranging the insertion pipe between the two joints, the insertion pipe can be reliably and linearly connected when the third segments are connected to each other.

The method of assembling a pipe according to the present invention is a method of assembling a tubular pipe constructed by arranging a plurality of segments in a staggered manner in the circumferential direction and the axial direction. A process of alternately arranging the segments and the second segment in the left-right direction along the axial direction, and a process of fitting the third segment into the gap between the left and right first segment and the second segment to construct a tubular shape. , And the third segment is arranged linearly in the axial direction.
According to the method of assembling a pipe in which the segments according to the present invention are arranged in a staggered manner, the first segment and the second segment having different lengths are alternately connected in the left-right direction along the axial direction, and the left-right first segment and the second segment are connected. By fitting the third segment into the gap between the two segments, the third segments can be connected linearly in the axial direction while the pipes are constructed in a staggered manner.

In the method of assembling a pipe and a pipe according to the present invention, the segments can be constructed in a staggered arrangement, and the third segment can be constructed linearly in the axial direction without shifting in the circumferential direction. Therefore, an insertion tube or a hole for inserting the cable can be formed in the third segment and arranged in a straight line. At that time, since only one type of third segment is required, the segment can be easily manufactured and assembled, and the manufacturing cost can be reduced.

It is sectional drawing orthogonal to the axial direction of the sewer pipe by embodiment of this invention. It is a main part plan view of the part of the K-shaped segment of the sewer pipe according to the embodiment. It is a perspective view of the K type segment. FIG. 3 is a cross-sectional view of a main part of the K-shaped segment shown in FIG. It is sectional drawing which shows the optical fiber cable, (a) is the figure of the cable with the primary coating, (b) is the figure of the cable with the secondary coating. It is sectional drawing which shows the formwork at the time of manufacturing a K type segment. It is a main part plan view which shows the assembly process of a sewer pipe. It is a main part plan view which shows the K type segment of the conventional sewer pipe and the insertion pipe.

Hereinafter, the sewer pipe 1 according to the embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view showing a sewer pipe 1 according to an embodiment of the present invention. This sewer pipe 1 is a substantially cylindrical shield tunnel excavated in the ground by a shield method, and has a diameter of, for example, about 2 m to 5 m. As a lining, the sewer pipe 1 is formed in a cylindrical shape by connecting plate-shaped RC segments curved in an arc shape in the circumferential direction by a joint portion to construct a segment ring 2 and sequentially connecting them in the axial direction. ..
At the time of excavation, the sewer pipe 1 is constructed by shield excavating the underground ground from the shaft side to the face side.

The segment ring 2 of the sewer pipe 1 is divided into, for example, five-piece segments, and the two-piece A-type segment 3 fixed to the bottom and the B1 type connected to both sides of the A-type segment 3 via joints. It includes segments 4A and 4B, and B2 type segments 5A and 5B. The B1 type segment 4A and the B1 type segment 4B, and the B2 type segment 5A and the B2 type segment 5B are line-symmetrical and have the same dimensions.
A K-type segment 6 is fitted as a key segment between the B1 type segment 4A and the B2 type segment 5B and between the B2 type segment 5A and the B1 type segment 4B, which are arranged so as to face each other in the circumferential direction. They are connected to each other. In this embodiment, the K-shaped segment 6 is attached to the top portion of the sewer pipe 1.

As shown in the plan view of the main part of FIG. 2, the A-type segments 3 of the sewer pipe 1 are connected to each other in the axial direction by a staggered arrangement. The circumferential length L1 of the B1 type segments 4A and 4B is formed shorter than the circumferential length L2 of the B2 type segments 5A and 5B, and the B1 type segments 4A, 4B and the B2 type segments 5A and 5B are the K type segments 6. The peripheral end portion on the side that comes into contact with the surface is formed on the inclined surfaces 4c and 5c in a plan view. Therefore, the space for fitting the K-shaped segment 6 is formed in a tapered shape from the cutting edge side toward the shaft side.
In each segment ring 2, when the end of the A-type segment 3 on the K-type segment 6 side protrudes in the circumferential direction, the short B1 type segments 4A and 4B are connected, and the K-type of the A-type segment 3 is connected. When the end on the segment 6 side is retracted in the circumferential direction, B2 type segments 5A and 5B having a large length are connected.

In the sewer pipe 1 shown in FIG. 2, the circumferential end of the A-type segment 3 of the other segment ring 2 adjacent in the axial direction protrudes from the circumferential end of the A-type segment 3 of the segment ring 2. The length or recess length is set to (L2-L1).
As a result, the inclined surfaces 4c and 5c of the B1 type segments 4A and 4B and the B2 type segments 5A and 5B are arranged at the same positions in the axial direction. The K-type segments 6 mounted in the gaps between the 4B and B2 type segments 5A are fixed at the same positions in the axial direction.

Next, the K-shaped segment 6 will be described with reference to FIGS. 3 and 4.
The K-shaped segment 6 has a substantially trapezoidal plate shape in a plan view and is formed by being curved in an arc shape, the inner peripheral surface thereof is a concrete surface, and the outer peripheral surface is fixed with a skin plate. On the four surfaces sandwiched between the inner peripheral surface and the outer peripheral surface, the main girder surface 8a is provided on the top side of the trapezoid, and the main girder surface 8b is provided on the bottom side. The main girder surface 8a on the top side of the trapezoid is arranged on the shaft side, the main girder surface 8b on the bottom side of the trapezoid is arranged on the face side, and the main girder surface 8a is shorter than the main girder surface 8b. There is.

Joint surfaces 9a and 9b are provided on both sides of the K-shaped segment 6 in the circumferential direction. The joint surfaces 9a and 9b are inclined surfaces that abut on the inclined surfaces 4c of the B1 type segments 4A and 4B and the inclined surfaces 5c of the B2 type segments 5A and 5B, respectively. Two bolt boxes 11 are provided on the main girder surfaces 8a and 8b of the K-shaped segment 6, respectively, and one main girder surface 8a (or main girder surface 8b) has a male portion 12a such as a pin bolt on the other. A female portion 12b such as a wedge is provided on each of the main girder surface 8b (or the main girder surface 8a).

FIG. 4 shows a horizontal cross section of the K-shaped segment 6 in line AA in FIG. 3, and shows the reinforcing bars arranged in a grid pattern in the concrete 15 between the main girder surfaces 8a and 8b of the K-shaped segment 6. , A steel insertion pipe 14 for laying a cable is embedded. The insertion pipe 14 is embedded in the center of each of the main girder surfaces 8a and 8b facing each other. The insertion pipe 14 has a length equal to the distance between the main girder surfaces 8a and 8b, and a part (one end portion) protrudes from one main girder surface 8a side as a protrusion 14a and the other main girder surface 8b side. At (the other end), it is depressed in the recess 16.
The insertion pipe 14 is embedded in the concrete 15 of the K-shaped segment 6 by one or a plurality of flange-shaped stoppers 17 projecting in the radial direction and being connected by welding or the like. The stopper 17 is a plate material that protrudes in a direction orthogonal to the insertion pipe 14, and can prevent the insertion pipe 14 from being displaced. In the example shown in FIG. 4, two stoppers 17 are arranged at intervals. Two bolt boxes 11 are fixed to the opposing main girder surfaces 8a and 8b of the K-shaped segment 6, and an insertion pipe 14 is embedded between the two bolt boxes 11. The insertion pipe 14 between the K-shaped segments 6 can be accurately positioned and fixed by each of the two bolt boxes 11.

Normally, the K-shaped segment 6 has a trapezoidal shape in a plan view and a narrow width of the main girder surface, but in the present embodiment, the K-shaped segment 6 is wide enough to install two bolt boxes 11 on the main girder surfaces 8a and 8b, respectively. It is formed.
Therefore, when the K-shaped segment 6 is connected in the spindle direction, the male portion 12a and the female portion 12b of the bolt box 11 can be connected to each other. Moreover, the protrusion 14a of the insertion pipe 14 provided in one K-shaped segment 6 is fitted into the recess 16 of the other adjacent K-shaped segment 6 and positioned. Therefore, when the sewer pipe 1 is constructed in a staggered manner in each segment, the K-shaped segments 6 are linearly arranged, and the insertion pipe 14 is also linearly connected. A cable such as an optical fiber cable or an electric wire cable can be easily inserted into the insertion tube 14.

FIG. 5 shows an example of an optical fiber cable. The optical fiber cable 18 shown in FIG. 5A is an optical fiber 19 coated with a multilayer 20, and the multilayer 20 is made of an ultraviolet curable resin. Has been done. The optical fiber cable 21 shown in FIG. 2B is an optical fiber 19 coated with a primary double glazing 22 and a secondary double glazing 23 made of an ultraviolet curable resin.
The insertion tube 14 is formed to have an inner diameter of, for example, 2 to 3 cm, and the optical fiber cables 18 and 21 are formed to have outer diameters of, for example, 0.25 mm and 0.9 mm, and can be inserted into the insertion tube 14. The optical fiber cables 18 and 21 are not limited to those inserted in the insertion tube 14 by themselves, and a plurality of optical fiber cables 18 and 21 can be bundled and inserted into the insertion tube 14.

The sewer pipe 1 according to the present embodiment has the above-described configuration, and then a method of assembling the sewer pipe 1 will be described.
First, a method of manufacturing the K-shaped segment 6 will be described with reference to FIG.
In the formwork 25 of the K-shaped segment 6, reinforcing bars (not shown) are arranged in a grid pattern, for example, inside the formwork 25. The first hole 26a and the second hole 27a are formed in the center of the first surface 26 and the second surface 27 corresponding to the main girder surfaces 8b and 8a of the K-shaped segment 6. A conical sealing body 28 is provided in the center of the inside of the first hole 26a of the first surface 26 to seal the first hole 26a, and the second hole 27a of the second surface 27 is penetrated from the lower side to the outside. An insertion tube 14 having a protruding portion 14a is provided.

A stopper 17 is fixed to the insertion pipe 14 in advance by welding or the like. Then, inside the first surface 26 and the second surface 27, male and female parts of the bolt box 11 are installed on both sides of the insertion pipe 14, respectively.
In this state, the concrete 15 is filled in the formwork 25 through a filling port (not shown), and the K-shaped segment 6 of the RC segment is placed. The other A-type segments 3, B1-type segments 4A and 4B, and B2-type segments 5A and 5B are also cast and manufactured in the same manner.

Next, an assembly method for assembling the sewer pipe 1 by the shield method will be described.
A shield excavator is inserted into the ground from the shaft, and the reaction force of the shield jack is used to excavate the ground with the shield excavator while advancing laterally to excavate a tunnel. On the wall of the excavated tunnel, segments are assembled into a substantially cylindrical zigzag set by an elector. The shield jack is pressed against the assembled segment ring 2 to further advance the shield excavator.
In FIG. 7, when constructing the segment ring 2, the A-type segments 3 and 3 are assembled at the bottom. Furthermore, after assembling the B1 type segment 4A and the B2 type segment 5B on both sides in the circumferential direction, the K type segment 6 is pushed into the gap between the uppermost B1 type segment 4A and the B2 type segment 5B from the face side with a shield jack and connected with a joint. To do.

When assembling the next segment ring 2, when the A-type segments 3 and 3 are assembled and connected in a staggered manner, the circumferential ends on both sides of the A-type segment 3 are the circumferential ends of the A-type segment 3 of the adjacent segment ring 2. It protrudes or is recessed by the length (L2-L1) with respect to the portion. Then, when the B1 type segment 4B and the B2 type segment 5A are assembled with respect to the adjacent segment ring 2, the inclined surfaces 4c and 5c at the ends of the B1 type segment 4A and 4B and the B2 type segment 5A and 5B are the same in the axial direction. Line up in position.
A trapezoidal K-shaped segment 6 is fitted from the face side into the gap between the B1 type segment 4B and the B2 type segment 5A of the segment ring 2. At the same time, the protrusion 14a of the insertion pipe 14 protruding from the main girder surface 8a on the distal end side is fitted into the recess 16 of the K-shaped segment 6 previously connected. Then, the K-type segments 6 are connected to each other by the male and female portions of the bolt box 11, and the joint surfaces 9a and 9b are connected to the left and right B1 type segments 4B and the inclined surfaces 4c and 5c of the B2 type segment 5A by the joint portions. ..

The sewer pipe 1 can be constructed by repeating the assembly work of such a segment. In this sewer pipe 1, the segments are staggered, but by connecting the B1 type segments 4A and 4B and the B2 type segments 5A and 5B alternately in the left-right direction at each segment ring 2, the K-type segment 6 is used as the axis. It can be arranged linearly in the direction. Moreover, the insertion pipe 14 of each K-shaped segment 6 can be linearly connected by the protrusion 14a and the recess 16. Therefore, after the construction of the sewer pipe 1, a cable such as an optical fiber cable or an electric wire cable can be smoothly inserted into the insertion pipe 14 of the K-shaped segment 6.

As described above, according to the sewer pipe 1 according to the present embodiment, since the segment in which the insertion pipe 14 into which the cable is inserted is embedded is only the K-shaped segment 6, it is easy to manufacture the segment at the factory and the cost is low.
Further, even though the segments are staggered, the K-shaped segment 6 can be arranged linearly on the top of the sewer pipe 1, so that the insertion pipe 14 can also be arranged linearly without any error. Easy and smooth to insert. Moreover, the insertion pipe 14 in each K-shaped segment 6 can be linearly connected to each other by the protrusion 14a from one main girder surface 8a and the recess 16 of the other main girder surface 8b. Therefore, mistakes in assembling the sewer pipe 1 by each segment are unlikely to occur, and assembling on site is easy.

Since the K-shaped segment 6 is arranged at the top of the sewer pipe 1 and the insertion pipe 14 is embedded in the concrete, even if the water level of the sewage rises, it does not immerse under the water surface and the cable can be easily managed. Moreover, since the insertion pipe 14 in the K-shaped segment 6 is arranged between the two bolt boxes 11 of the main girder surfaces 8a and 8b facing each other, it is possible to connect the plurality of continuous K-shaped segments 6 with high accuracy. Can be done.
Further, according to the method of assembling the sewer pipe 1 according to the embodiment, by pushing the K-type segment 6 from the face side, it can be fitted in the gap between the B1 type segments 4A and 4B and the B2 type segments 5A and 5B, and is adjacent to each other. The protrusion 14a of the insertion pipe 14 can be fitted in the recess 16 of the K-shaped segment 6 of the segment ring 2.

Although the sewer pipe 1 and the method of assembling the sewer pipe 1 according to the embodiment of the present invention have been described in detail above, the present invention is not limited to the above-described embodiment and may be appropriately modified without departing from the spirit of the present invention. Substitutions and the like are possible, all of which are included in the present invention. Hereinafter, modifications of the present invention and the like will be described, but the description will be omitted by using the same reference numerals for the same or similar parts and members as those in the above-described embodiment.

For example, in the above-described embodiment, the insertion pipe 14 of the K-shaped segment 6 is arranged between the two bolt boxes 11, but one bolt box 11 may be installed on one side of the insertion pipe 14. .. Further, instead of the bolt box 11, various joints such as bolts / nuts and ring joints can be adopted.
Further, in the above-described embodiment, the insertion pipe 14 is connected to the top (ceiling portion) of the cylindrical sewer pipe 1, but since the insertion pipe 14 and the fiber are embedded in the concrete of the K-shaped segment 6, the sewerage system is used. It may be arranged on the side portion of the pipe 1 or may be disposed on the bottom portion.

Further, in the above-described embodiment, the insertion pipe 14 embedded in the K-shaped segment 6 has a protrusion 14a protruding from one main girder surface 8a (end surface) and retracted into a recess of the other main girder surface 8b (end surface). However, it does not necessarily have to have the protrusion 14a. The insertion tube 14 may be formed flush with both end faces, for example, with the same length as the K-shaped segment 6.
Even in this case, since the K-shaped segment 6 is linearly connected by the bolt box 11, the insertion pipe 14 is also linearly connected, and the cable can be inserted.
Further, in the above-described embodiment, in the sewer pipe 1 arranged in a staggered manner, the insertion pipes 14 of the K-shaped segments 6 arranged in the axial direction are arranged in a straight line so that the fibers can be inserted, but the fibers can be inserted into the K-shaped segments 6. Instead of the insertion tube 14, the hole may be formed in a straight line so that the fiber can be inserted.

In the above-described embodiment, the cylindrical sewer pipe 1 has been described, but the present invention is not limited to the cylindrical shape, and can be applied to a pipe having an appropriate cross-sectional shape such as a square cylinder shape.
Further, the present invention is not limited to the sewer pipe 1, and can be installed in various segment tunnels such as railway tunnels, subway tunnels, mountain tunnels, underground tunnels, and above-ground tunnels. it can.
The segment used for the pipe according to the present invention is not limited to the RC segment, but can also be adopted for a steel segment, a synthetic segment, or the like. The B1 type segments 4A and 4B are included in the first segment, the B2 type segments 5A and 5B are included in the second segment, and the K type segment is included in the third segment. Further, the bolt box 11 is included in the joint portion.

1 Sewer pipe 2 Segment ring 3 A type segment 4A, 4B B1 type segment 5A, 5B B2 type segment 6 K type segment 11 Bolt box 14 Insertion pipe 14a Protrusion 15 Concrete 16 Recess 17 Stopper 18, 21 Optical fiber cable

Claims (6)

In a tubular pipe constructed by arranging multiple segments in a staggered manner in the circumferential direction and the axial direction.
The first segment and the second segment, which are alternately arranged in the left-right direction along the axial direction and have different circumferential lengths,
The left and right first segment and the third segment fitted in the gap between the second segment are provided.
The third segment is a conduit characterized in that it is linearly connected in the axial direction without shifting its position in the circumferential direction. Further provided with an insertion pipe for cable laying embedded in the third segment,
The pipe according to claim 1, wherein the insertion pipe is linearly connected in the axial direction without shifting the position in the circumferential direction. A claim in which one end of an insertion tube embedded in the third segment protrudes from one end face of the third segment, and the other end is retracted inside the other end face facing the one end face. The pipe according to Item 1 or 2. The pipe according to claim 2 or 3, wherein the insertion pipe has a stopper fixed to a concrete-filled portion in the third segment. The third segment according to any one of claims 2 to 4, wherein two joint portions are provided at the axially connecting portion, and the insertion pipe is arranged between the two joint portions. Pipe. In the method of assembling a tubular pipe constructed by arranging a plurality of segments in a staggered manner in the circumferential direction and the axial direction.
When assembling the segments into a tubular shape, a step of alternately arranging the first segment and the second segment having different lengths in the left-right direction along the axial direction, and
A step of forming a tubular shape by fitting the third segment into the gap between the left and right first segment and the second segment is provided.
A method for assembling a pipe, wherein the third segment is arranged linearly in the axial direction.

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