JP2000204516A - Bridge attaching device and construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the load of an attaching device on a bridge by forming a protection pipe and a pipe support for the protection pipe of a fiber reinforced plastic. SOLUTION: A pipeline network is formed by inserting a plurality of sheath pipes housing optical fiber cables into a large diameter body pipe and laying underground. When making the pipeline network cross a river portion, an FRP body pipe 12A housing a plurality of FRP sheath pipes 11A is attached to a bridge girder 3 and pipes 11A and 12A are connected to the sheath pipes and the body pipes in the ground through a hand hole, respectively, and an optical fiber cable in each of the sheath pipes is connected. Subsequently, the pipes 11A and 12A are formed by connecting a plurality of pipes, and flexible joints or expansion joints are provided in the connections and the connection of the body pipe in the hand hole. The pipe 11A is fixed to the FRP pipe support 31 fixed to the bridge girder 3 with an FRP fastener 32, thereby reducing weight, lessening load on the bridge and securing earthquake resistance, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bridge supporting device and a construction method suitable for constructing an information box support line system and the like.

[0002]

2. Description of the Related Art When laying a pipeline network of cables such as optical fiber cables for constructing an information box support line system, a protective tube using a corrosion-resistant steel pipe or the like through which the cables are inserted is used. The bridge is traversed along a bridge using pipe supports made of steel.

[0003]

When a protective tube for cables is attached to a bridge, it is necessary to reduce the load on the bridge by the attaching device as much as possible. In particular, the truck load is increased due to the revision of the Road Traffic Law. In this case, it is required to further reduce the load on the bridge of the supporting device.

[0004] It is an object of the present invention to reduce the load on a bridge of an extension device when attaching a protective tube for cables to a bridge.

[0005]

According to the present invention, there is provided a bridge mounting apparatus for mounting a protective pipe, through which cables are inserted, on the bridge by using a pipe support fixed to the bridge. The protective tube attached to the bridge is formed of fiber-reinforced plastic, and the pipe support is formed of fiber-reinforced plastic.

According to a second aspect of the present invention, in the first aspect of the present invention, at least a portion of the protective tube attached to a bridge connects a plurality of tubes with a flexible connecting portion. It is made to be.

According to a third aspect of the present invention, in the first or the second aspect of the present invention, the portion of the protective tube attached to the bridge is a flexible expansion joint near the inside of the abutment. Through an underground protection pipe.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the underground protection pipe is formed by connecting a plurality of pipes, and these pipes are connected to the outer side of the abutment. These are connected to each other via a flexible joint.

The present invention according to claim 5 provides the invention according to claims 1-4.
When the protective tube according to any one of the above, is a body tube which accommodates and extends a plurality of sheath tubes through which cables are inserted, after the body tube is completely attached to the bridge, it is attached to the bridge. This is a bridge mounting method in which a sheath pipe is extended from one end of the body pipe to the other end.

Hereinafter, the fiber reinforced plastic is referred to as FRP.

[0011]

According to the first aspect of the present invention, the following effects are obtained. The protection pipe made of FRP is as light as about 1/5 of steel pipe, and can reduce the load on the bridge. The protective tube has sufficient strength, is resistant to shock and vibration, and is excellent in weather resistance, heat resistance, cold resistance, and corrosion resistance. In addition, the inside surface of the pipe is smooth, and the work of connecting cables can be performed smoothly.

The tube support made of FRP is lightweight and can reduce the load on the bridge. The tube support has sufficient strength, is resistant to shock and vibration, and is also excellent in weather resistance, heat resistance, cold resistance, and corrosion resistance.

According to the above, the total weight of the bridge mounting device including the protective tube and the pipe support is secured, and the load on the bridge can be reduced.

According to the second aspect of the present invention, the following operations are provided. Since the part of the protective tube attached to the bridge is made up of multiple tubes connected by flexible connecting parts, it absorbs the displacement between the protective tubes due to the relative displacement between the abutment and the bridge girder due to an earthquake or the like. it can.

According to the third aspect of the present invention, the following operations are provided. The portion of the protection tube attached to the bridge was connected to the underground protection tube via a flexible expansion joint near the inside of the abutment. Therefore, it is possible to absorb the displacement between the protection tubes due to the relative displacement between the abutment and the bridge girder due to an earthquake or the like, and the expansion and contraction due to the thermal expansion between the protection tubes.

According to the present invention, the following effects are obtained. Underground laid protective tubes connected the multiple tubes, which were connected to each other via flexible joints on the outer side of the abutment. Therefore, the displacement between the protection tube on the abutment side and the protection tube on the handhole side based on the relative displacement between the abutment and the ground due to an earthquake or the like can be absorbed.

According to the present invention, the following effects are obtained. When installing the body tube and sheath tube that constitute the protective tube on the bridge, rather than extending the body tube and sheath tube simultaneously and in parallel, attach the body tube first to the bridge and then attach it to this body tube. Extending the sheath through the tubing improves workability and prevents the pod from falling.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view showing a bridge supporting apparatus for a body pipe according to a first embodiment, FIG. 2 shows a bridge supporting structure for a body pipe, (A) is a front view, and (B) is a side view. FIGS. 3A and 3B show a body tube, and FIG.
(B) is a half-sectional view showing a double-inserted straight pipe, (C) is a half-sectional view showing a flexible joint, (D) is a half-sectional view showing a flexible expansion joint, and FIG. 4 shows a structure of an FRP pipe. FIG. 5 is a cutaway view, FIG. 5 is a side view showing a bridge mounting device of a sheath pipe of the second embodiment, FIG. 6 is a front view showing a bridge mounting structure of a sheath tube, and FIG. 7 is a first modification of the bridge mounting structure of a sheath tube. (A) is a front view, (B)
Is a side view, FIG. 8 is a front view showing a second modified example of the bridge extension structure of the sheath pipe, and FIG. 9 is a front view showing a third modification example of the bridge extension structure of the sheath pipe.

(First Embodiment) (FIGS. 1 to 4) FIG. 1 shows a case where optical fiber cable pipeline networks for constructing an information box support line system are laid underground. A protection tube 10 through which an optical fiber is inserted is attached to a bridge 1 and crosses a river. The bridge 1 includes an abutment 2 and a bridge girder 3 mounted thereon.

The pipe network of the optical fiber cable is laid underground by inserting the optical fiber cable through a plurality of sheath pipes 11 (not shown) accommodated in a large-diameter body pipe 12 (not shown). When crossing the above-mentioned river section of the pipeline network, a handhole 13 is provided near the bridge 1 to which an underground sheath sheath 11 and a body pipe 12 are connected.
The protective tube 10 attached to the bridge girder 3 is made of an FRP body tube 12A accommodating a plurality of FRP sheath tubes 11A, and the sheath tube 11A and the body tube 12A are made of corrosion-resistant steel tube 11B (not (Shown) and a hand hole 13 via a corrosion-resistant steel pipe body tube 12B. Note that the sheath tube 11A may be made of general plastic without using FRP. In addition, sheath tube 11
An optical fiber cable is passed through A and 11B, and this optical fiber cable is continuous with the optical fiber cable of the opposing sheath 11 in the handhole.

The body pipe 12A (the sheath pipe 11A also has the same configuration) attached to the bridge 1 is a single straight pipe 2 shown in FIG.
1 (the body pipe 12A has a large diameter, and the sheath pipe 11A has a small diameter), and the two straight pipes 22 (the body pipe 12A) shown in FIG.
A is a large-diameter connector, and sheath tube 11A is a small-diameter connector.
The straight end of the other one-side receiving tube 21 is inserted into a rubber ring 21B built in the receiving portion 21A provided at one end of the one-side receiving tube 21, or the receiving portions of the two-side receiving straight tubes 21 facing each other from the left and right. Both straight ends of both insertion straight pipes 22 are inserted into rubber rings 21B of 21A or connected via flexible joints 23A (FIG. 3 (C)). The receiving port 21A of the straight receiving pipe 21 constitutes an expansion joint that absorbs expansion and contraction caused by thermal expansion of the body pipe 12A by the rubber ring 21B. The flexible joint 23A is inserted until the straight ends of the tubes 21 and 22 pass through the rubber ring 111 and abut against the stopper 112, and absorb the displacement of the tubes 21 and 22 by the displacement of the rubber ring 111.

The body tube 12B (the same structure as the sheath tube 11B) connected to the handhole 13 is provided on the inner side of the abutment 2 near the abutment 2 and the relative displacement between the abutment 2 and the bridge girder 3 due to an earthquake or the like. The other end of the one-sided straight pipe 21 constituting the body tube 12A (the sheath tube 11A) via a flexible expansion joint 23B (FIG. 3D) that absorbs expansion and contraction due to thermal expansion of the body tube 12A and the body tube 12B. Connected to the straight end of the In addition, the flexible expansion joint 23B passes the straight end of the other end of the tube 21 constituting the body tube 12A and the straight end of the body tube 12B through the rubber ring 121 to form the body tube 12A.
And one straight end of the body tube 12B with the stopper 12
2 so that the body tubes 12A and 12B can expand and contract within a range of separation from the stopper 122. At least the rubber ring 121 on the side where the body tubes 12A and 12B extend and contract moves with a low insertion force. It is made of rubber.

When the underground body pipe 12B is connected to a plurality of pipes (corrosion-resistant steel pipes), the pipes are connected to the outside of the abutment 2 via the flexible joint 23A. You are going to.

At this time, the body tube 12A (the sheath tube 11A)
4 is made of FRP as described above. For example, a high-strength glass fiber is used in the circumferential direction and the axial direction, and is formed by curing with a thermosetting unsaturated polyester resin. As shown in the figure, a corrosion-resistant protective layer A comprising an organic fiber and a resin, a circumferential glass mat and a resin layer B, an axial glass roving and a resin layer C, a circumferential glass mat and a resin layer D, an axial glass roving and a resin layer E, a circumferential glass mat and a resin layer F, and a corrosion-resistant protective layer G made of an organic fiber and a resin.

However, in the present embodiment, the protective tube 1
0, the above-mentioned body pipe 12A is attached to a pipe support 31 fixed to the bridge girder 3 of the bridge 1 as shown in FIG.
It is fixed and supported by the fixture 32. Pipe support 31
Is formed by assembling a shaped steel 33 with bolts 34 and nuts 35, and is fixed with nuts 37 to planting bolts 36 on the bridge girder 3. At this time, the shape steel 33 constituting the pipe support 31 can be made of the same FRP as the body pipe 12A described above, and the bolt 34, the nut 35, the bolt 36, and the nut 37 are provided.
Can also be made of FRP. In addition, the fixture 32
A band band (or U-bolt) 38 is attachable to the pipe support 31 with a nut 39 and a washer 39A. The band band 38, the nut 39, and the washer 39 are provided.
A can also be made of FRP.

In the present embodiment, when the body pipe 12A and the sheath pipe 11A are attached to the bridge 1 to cross the river, the body pipe 12A is attached to the bridge 1 over the entire length of the bridge 1 as described above. The body pipe 12A attached to the bridge 1 can extend from one end to the other end through the sheath pipe 11A.

Therefore, according to the present embodiment, the following operations are provided. The protection pipe 10 made of FRP is as light as about 1/5 of a steel pipe and can reduce the load on the bridge. The protective tube 10
Has sufficient strength, is resistant to shock and vibration, and is also excellent in weather resistance, heat resistance, cold resistance, and corrosion resistance. In addition, the inner surface of the pipe is smooth, and the work of passing the optical fiber cable can be performed smoothly.

The pipe support 31 made of FRP is lightweight and can reduce the load on the bridge. The tube support 31
Has sufficient strength, is resistant to shock and vibration, and is also excellent in weather resistance, heat resistance, cold resistance, and corrosion resistance.

As described above, the light weight and the like of the bridge mounting device including the protective tube 10 and the tube support 31 can be secured in total, and the load on the bridge can be reduced in total.

The portion of the protective tube 10 attached to the bridge 1 is formed by connecting a plurality of tubes 21 and 22 with flexible connecting portions (receiving ports 21A and flexible joints 23A). The displacement between the protection tubes 10 based on the relative displacement between the abutment 2 and the bridge girder 3 due to an earthquake or the like can be absorbed.

The portion of the protective tube 10 attached to the bridge 1 was connected to the underground laid protective tube 10 via a flexible expansion joint 23B on the inner side of the abutment 2. Therefore, displacement between the protection tubes 10 due to relative displacement between the abutment 2 and the bridge girder 3 due to an earthquake or the like, and expansion and contraction due to thermal expansion between the protection tubes 10 can be absorbed.

An underground protection pipe 10 connects a plurality of pipes, and these pipes are connected to each other on the outer side of the abutment 2 via a flexible joint 23A. Therefore, the displacement between the protection tube 10 on the abutment 2 side and the protection tube 10 on the handhole side based on the relative displacement between the abutment 2 and the ground due to an earthquake or the like can be absorbed.

When installing the body tube 12A and the sheath tube 11A constituting the protection tube 10 on the bridge 1, the body tube 12A is first extended rather than extending the body tube 12A and the sheath tube 11A simultaneously and in parallel. It is more workable to extend the bridge 1 to the bridge 1 and then extend the sheath tube 11A through the sheath tube 11A, thereby improving the workability and preventing the sheath tube 11A from dropping.

(Second Embodiment) (FIGS. 5 and 6) The second embodiment is different from the first embodiment in that an underground cable is laid near a bridge 1 when crossing a river network of an optical fiber cable pipeline network. A handhole 13 is provided to connect a sheath pipe 11 (not shown) and a body pipe 12 (not shown), and a plurality of FRP sheath pipes 11A are provided with a plurality of protective tubes 10 attached to the bridge girder 3 of the bridge 1. And the sheath tube 11A is connected to the handhole 13 via a sheath tube 11B made of a corrosion-resistant steel tube. Sheath tube 11A, 1
An optical fiber cable is passed through 1B, and this optical fiber cable is continuous with the optical fiber cable of the sheath tube 11.

The sheath tube 11A attached to the bridge 1 is the first tube.
The small-diameter one-piece straight receiving pipe 21 shown in FIG.
FIG. 3B is a connecting body of the small-diameter double-inserted straight pipe 22, and a rubber ring 21 </ b> B built in a receiving port 21 </ b> A provided at one end of the single-received straight pipe 21. Receiving port 2 of straight receiving pipe 21 with straight end inserted or opposed from left and right
Both straight ends of both insertion straight pipes 22 are inserted into the rubber ring 21B of 1A or connected by using a flexible joint 23A.
The receiving port 21A of the straight receiving pipe 21 constitutes an expansion joint that absorbs expansion and contraction due to thermal expansion of the sheath pipe 11A by the rubber ring 21B.

The sheath tube 11B connected to the handhole 13 is located on the inner side of the abutment 2 and causes relative displacement between the abutment 2 and the bridge girder 3 due to an earthquake or the like, and thermal expansion of the sheath tube 11A and the sheath tube 11B. Flexible joint 23 that absorbs expansion and contraction due to
B, the above-mentioned single receiving straight tube 2 constituting the sheath tube 11A.
1 is connected to the other straight end.

Further, when the sheath pipe 11B laid underground is used as a connecting body of a plurality of pipes (sheath pipes made of corrosion-resistant steel pipe),
The tubes are connected to the outside of the abutment 2 by a flexible joint 23A.

At this time, the sheath tube 11A is made of the same FRP as the body tube 12A described in the first embodiment (FIG. 4).

However, in this embodiment, the protection tube 1
As shown in FIG. 6, the above-mentioned plurality of sheath tubes 11A constituting the support 0 are fixed to and supported by a tube support 41 which is fixed between bridges of the bridge girder 3 of the bridge 1 by a fixture 42. Is done. The pipe support 41 fixes the shaped steel 43 to the bridge girder 3 with bolts and nuts (not shown). At this time, the pipe support 41
Is made of the same F as the sheath tube 11A described above.
It can be made of RP, and the bolts and nuts can also be made of FRP. In addition, the fixture 42 has an intermediate short cleat 44C interposed between the upper and lower long cleats 44A and 44B, and for example, three sheath tubes 11A are inserted between the long cleat 44A and the short cleat 44C. For example, three sheath tubes 11A between the short cleats 44C and the short cleats 44C.
Are clamped by a three-stage, two-stage sheath tube 11A, and the whole of these can be fastened to the shaped steel 43 of the tube support 41 by bolts 45 and nuts (not shown). The 44A to 44C, the bolt 45, and the nut can also be made of FRP.

The cleats 44A to 44C have a hollow structure in which caps are attached to both ends of a hollow square pipe to reduce the weight. Each of the cleats 44A to 44C has an arc-shaped notch 46 on which the sheath tube 11A is seated. In addition, a space or an arc-shaped notch 46
Can also be provided.

Therefore, according to the present embodiment, the following operations are provided. The protection pipe 10 made of FRP is as light as about 1/5 of a steel pipe and can reduce the load on the bridge. The protective tube 10
Has sufficient strength, is resistant to shock and vibration, and is also excellent in weather resistance, heat resistance, cold resistance, and corrosion resistance. In addition, the inner surface of the pipe is smooth, and the work of passing the optical fiber cable can be performed smoothly.

The tube support 41 made of FRP is lightweight and can reduce the load on the bridge. The tube support 41
Has sufficient strength, is resistant to shock and vibration, and is also excellent in weather resistance, heat resistance, cold resistance, and corrosion resistance.

As described above, the light weight and the like of the bridge supporting device including the protective tube 10 and the tube support 41 are secured in total, and the load on the bridge can be reduced in total.

The portion of the protective tube 10 attached to the bridge 1 is formed by connecting a plurality of tubes 21 and 22 with flexible connecting portions (receiving port 21A, flexible joint 23A). The displacement between the protection tubes 10 based on the relative displacement between the abutment 2 and the bridge girder 3 due to an earthquake or the like can be absorbed.

The portion of the protective tube 10 attached to the bridge 1 was connected to the underground laid protective tube 10 via a flexible expansion joint 23B near the inside of the abutment 2. Therefore, displacement between the protection tubes 10 due to relative displacement between the abutment 2 and the bridge girder 3 due to an earthquake or the like, and expansion and contraction due to thermal expansion between the protection tubes 10 can be absorbed.

An underground protection pipe 10 connects a plurality of pipes, and these pipes are connected to each other on the outer side of the abutment 2 via a flexible joint 23A. Therefore, the displacement between the protection tube 10 on the abutment 2 side and the protection tube 10 on the handhole side based on the relative displacement between the abutment 2 and the ground due to an earthquake or the like can be absorbed.

(First Modification) (FIG. 7) In a first modification, as shown in FIG. 7, a pipe support in which a plurality of sheath tubes 11A constituting a protective tube 10 are suspended from a bridge girder 3 of a bridge 1 is shown. The fixture 51 was fixed and supported by a fixture 52. The tube support 51 includes a suspension bolt 53, and the suspension bolt 53 can be made of the same FRP as described above. Further, the fixing tool 52 has an intermediate cleat 54C interposed between upper and lower cleats 54A and 54B similar to the above-described cleat 44A, and an upper cleat 54A and an intermediate cleat 54A.
C, for example, three sheath tubes 11A are attached to the lower cleat 54.
B and the intermediate cleat 54C, for example, three sheath tubes 11
A is sandwiched between the three-stage and two-stage sheath pipes 11A in total, and the whole of these is connected to upper and lower nuts 55A, 55B and washers 56.
A and 56B, which can be fastened to the suspension bolt 53. These crews 54A to 54C, nuts 55A,
5B and washers 56A and 56B can also be made of FRP. In addition, cleats 54A to 54C are sheathed pipes 11A.
Is provided with an arc-shaped notch portion 57 for seating.

(Second Modification) (FIG. 8) In a second modification, as shown in FIG. 8, a plurality of sheath tubes 11A constituting the protection tube 10 are fixed to the bridge girder 3 of the bridge 1 by side. The tube support 61 was fixed and supported by a fixture 62. The pipe support 61 is formed by assembling a shaped steel 63 and a square pipe 64 with bolts 65 and nuts (not shown), and is fixed to bolts 66 laid on the bridge girder 3 with nuts 67. The bolt 64, the bolt 65, the bolt 66, and the nut 67 can be made of FRP. In addition, fixture 6
2 is an upper long cleat 68 similar to the aforementioned cleat 44A.
An intermediate short cleat 68B is interposed between A and the square pipe 64, and for example, three sheath tubes 11A are inserted between the upper long cleat 68A and the intermediate short cleat 68B, and between the square pipe 64 and the intermediate short cleat 68B. For example, three sheath tubes 11A
Are clamped by a three-stage, two-stage sheath tube 11A, and the whole of these can be fastened to the square pipe 64 by bolts 69, nuts 70, and washers 70A. These cleats 68A, 68B, bolts The 69, the nut 70, and the washer 70A can also be made of FRP. In addition, cleat 6
8A, 68B and the square pipe 64 are provided with an arc-shaped notch 71 on which the sheath tube 11A is seated.

(Third Modification) (FIG. 9) In a third modification, as shown in FIG. 9, a plurality of sheath pipes 11A constituting the protection tube 10 are fixed to the bridge girder 3 of the bridge 1 by side. It was fixed and supported on a tube support 81 by a fixture 82. The fixture 82 is formed by assembling a shaped steel 83 with bolts 84 and nuts (not shown).
85B, and a nut 87
The steel 83, bolt 84, bolt 8
6. The nut 87 can be made of FRP. Also,
The fixture 82 includes three U bolts 88 on the upper pipe support 85A.
A is attached with nuts 89A and washers 90A, and all three sheath tubes 11A are attached to the lower tube support portion 85B by three U bolts 8.
8B is attached with a nut 89B and a washer 90B so that a total of three sheath tubes 11A can be fastened to a three-stage, two-stage sheath tube 11A.
8B, nuts 89A, 89B, washers 90A, 90B
Can be made of FRP.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design may be changed without departing from the scope of the present invention. The present invention is also included in the present invention. For example, the cables common to the protection tubes attached to the bridge according to the present invention are not limited to optical fiber cables, but may be other communication cables, power cables, or the like.

[0051]

As described above, according to the present invention, it is possible to reduce the load on the bridge of the supporting device when the protective tube for cables is mounted on the bridge.

[Brief description of the drawings]

FIG. 1 is a side view showing a bridge attaching device for a body pipe according to a first embodiment.

FIG. 2 shows a bridge attachment structure of a body pipe, and (A)
Is a front view, and (B) is a side view.

3A and 3B show a body tube, FIG. 3A is a half sectional view showing a one-sided straight tube, FIG.
(C) is a half sectional view showing a flexible joint, and (D) is a half sectional view showing a flexible expansion joint.

FIG. 4 is a cutaway view showing the structure of an FRP tube.

FIG. 5 is a side view showing a bridge attaching device for a sheath pipe of a second embodiment.

FIG. 6 is a front view showing a bridge supporting structure of a sheath pipe.

FIGS. 7A and 7B show a first modification of the bridge supporting structure of the sheath tube, wherein FIG. 7A is a front view and FIG. 7B is a side view.

FIG. 8 is a front view showing a second modification of the bridge supporting structure of the sheath pipe.

FIG. 9 is a front view showing a third modification of the bridge extension structure of the sheath pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bridge 10 Protective tube 11A sheath tube 12A Body tube 31, 41, 51, 61, 81 Pipe support tool 32, 42, 52, 62, 82 Fixing tool

Continuing on the front page (72) Nobuyuki Ozawa, 2082 Junwell, Ichihara-shi, Chiba Komatsu Chemicals Co., Ltd. (72) Inventor Mitsunori Sato, 2082 Junwell, Ichihara-shi, Chiba Komatsu, Ltd. (72) ) Inventor Masanori Takahashi 2082 Junwell, Ichihara-shi, Chiba Pref. (72) Inventor Kenji Nakai 3-4-7 Toranomon, Minato-ku, Tokyo Sekisui Chemical Co., Ltd. (72) Inventor Minamizawa Hiroko 4-13-13 Akasaka, Minato-ku, Tokyo F-term in Kyowa Exio Co., Ltd. 2D059 BB28 GG02

Claims (5)

[Claims] 1. A bridge mounting device in which a protective tube through which cables are inserted is fixed to the bridge by using a pipe support which is fixed to the bridge, wherein the protective tube attached to the bridge is formed of fiber-reinforced plastic. A bridge supporting device, wherein the pipe support is formed of fiber-reinforced plastic. 2. The bridge mounting apparatus according to claim 1, wherein at least a portion of the protection pipe attached to the bridge is formed by connecting a plurality of pipes with a flexible connecting portion. 3. A part of the protection tube attached to a bridge,
3. The bridge mounting device according to claim 1, wherein the underside of the abutment is connected to a protective pipe installed underground through a flexible expansion joint. 4. 4. The underground protection pipe according to claim 3, wherein the protection pipe connects a plurality of pipes, and the pipes are connected to each other via a flexible joint near the outside of the abutment. Bridge mounting device. 5. When the protective tube according to any one of claims 1 to 4 is a body tube that accommodates and extends a plurality of sheath tubes through which cables are inserted, A bridge mounting method, comprising, after completion of mounting on a bridge, extending a sheath pipe from one end to the other end of the body pipe mounted on the bridge.