JP7730073B2 - Buried pipe, joint member, buried pipe connection structure, and buried pipe installation method - Google Patents

Description

This disclosure relates to buried pipes, joint members, buried pipe connection structures, and buried pipe installation methods.

When various cables, such as optical fiber and power lines, are buried underground, it is known to use buried pipes to house the cables. When buried pipes are buried underground, such as beneath roads, to form buried conduits, there is a high risk of the buried conduits being damaged by excavation machinery such as cutters during road construction work, etc., in shallow sections where there is insufficient soil cover (the depth from the ground surface to the buried pipe) to cover the buried pipe.

To prevent damage to buried pipelines in shallow sections, it is known to install sign sheets indicating that the buried pipeline is buried, or iron, ceramic, or metal plates to prevent heavy machinery from entering, between the surface and the buried pipeline (Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 2001-355758 Japanese Patent Application Laid-Open No. 2007-143355 JP 2015-180166 A

In conventional configurations, the structure for preventing damage to buried pipelines is installed outside the buried pipe, requiring a certain amount of space between the ground surface and the buried pipe. However, in cases where the soil cover is shallow or where buried objects are congested, it can be difficult to ensure sufficient distance between the ground surface and the buried pipe, and conventional configurations may not be able to adequately protect the buried pipeline.

The purpose of this disclosure is to provide buried pipes, joint members, buried pipe connection structures, and buried pipe installation methods that can adequately protect buried pipelines even when it is difficult to ensure a sufficient distance from the ground surface to the buried pipe.

In one embodiment, the buried pipe comprises a plurality of inner pipes each having a hollow portion capable of accommodating a cable; an outer pipe that accommodates the plurality of inner pipes and has an inner surface having a portion that contacts the outer surface of each of the plurality of inner pipes; and a protective member provided in the space defined by the outer surfaces of the plurality of inner pipes and the inner surface of the outer pipe, wherein the strength of the protective member is greater than that of the plurality of inner pipes and the outer pipes.

In one embodiment, the coupling member is a coupling member for joining buried pipes, and comprises an inner pipe having a hollow portion that can be fitted with the connection portion of the buried pipe, an outer pipe that houses the inner pipe and has an inner surface with a portion that contacts the outer surface of the inner pipe, and a protective member provided in the space defined by the outer surface of the inner pipe and the inner surface of the outer pipe, wherein the strength of the protective member is greater than that of the inner pipe and the outer pipe, and the inner pipe has a fitting portion that leaves a gap between the inner pipe and the connection portion when the inner pipe is fitted.

One embodiment of the connection structure is a buried pipe connection structure comprising a buried pipe and a joint member that joins the buried pipe, wherein the buried pipe comprises: a plurality of first inner pipes having a hollow portion capable of accommodating a cable; a first outer pipe that accommodates the plurality of first inner pipes and has an inner surface having a portion that contacts the outer surface of each of the plurality of first inner pipes; a first protective member provided in a space defined by the outer surfaces of the plurality of first inner pipes and the inner surface of the first outer pipe; and a connecting portion that is connectable to the joint member and has a hollow portion that communicates with the hollow portions of the plurality of first inner pipes, and the first protective member The strength of the material is higher than that of the plurality of first inner pipes and the first outer pipe, and the joint member comprises a second inner pipe having a hollow portion that can be fitted with the connection portion of the buried pipe, a second outer pipe that accommodates the second inner pipe and has an inner surface having a portion that contacts the outer surface of the second inner pipe, and a second protective member provided in a space partitioned by the outer surface of the second inner pipe and the inner surface of the second outer pipe, and the strength of the second protective member is higher than that of the second inner pipe and the second outer pipe, and the second inner pipe has a fitting portion such that there is a gap between the second inner pipe and the connection portion when the second inner pipe is fitted.

In one embodiment, a buried pipe installation method includes connecting a first buried pipe comprising a plurality of first inner pipes each having a hollow portion capable of accommodating a cable, an outer pipe that accommodates the plurality of first inner pipes and has an inner surface having a portion that contacts the outer surface of each of the plurality of first inner pipes, and a protective member provided in a space defined by the outer surfaces of the plurality of first inner pipes and the inner surface of the outer pipe, wherein the strength of the protective member is greater than that of the plurality of first inner pipes and the outer pipe, and a second buried pipe comprising a plurality of second inner pipes each having a hollow portion capable of accommodating the cable, in accordance with the condition of the pipeline buried underground, and inserting the first buried pipe into an opening of the pipeline.

According to one embodiment of the present disclosure, buried pipelines can be adequately protected even when it is difficult to ensure a sufficient distance from the ground surface to the buried pipeline.

1 is a cross-sectional view showing an example of the configuration of a buried pipe according to one embodiment. FIG. 10 is a cross-sectional view showing another example of the configuration of the buried pipe according to the embodiment. FIG. 10 is a cross-sectional view showing another example of the configuration of the buried pipe according to the embodiment. FIG. 2 is a cross-sectional view showing an example of the protective member of FIG. 1 . FIG. 2 is a cross-sectional view showing an example of the protective member of FIG. 1 . FIG. 2 is a cross-sectional view showing an example of the protective member of FIG. 1 . FIG. 2 is a cross-sectional view showing an example of the protective member of FIG. 1 . FIG. 2 is a cross-sectional view showing an example of the protective member of FIG. 1 . 1 is a schematic diagram showing an example of a buried pipe connection structure in which multiple buried pipes are connected by joint members, the buried pipe connection structure being arranged in an underground pipeline. FIG. 1 is a perspective view showing an example of an inner pipe structure formed by integrally molding a plurality of inner pipes. FIG. FIG. 5B is a side view of the inner tube structure of FIG. 5A. 5B is a cross-sectional view of the inner pipe structure taken along line AA of FIG. 5A. FIG. 2 is a perspective view showing an example of an inner tube of a joint member. FIG. 6B is a front view of the inner tube of the coupling member of FIG. 6A. 6C is a cross-sectional view of the inner tube of the coupling member of FIG. 6B taken along line BB. 10A and 10B are diagrams showing an example in which two inner pipe structures are connected by an inner pipe of a joint member. 1 is a schematic diagram showing an example of a buried pipe connection structure in which a plurality of buried pipes are connected by joint members and arranged in an underground pipeline. 1 is a schematic diagram showing an example of a buried pipe connection structure in which a plurality of buried pipes are connected by joint members and arranged in an underground pipeline. 10 is a flowchart showing a procedure for installing a buried pipe in a pipeline.

One embodiment of the present disclosure will be described below with reference to the drawings. In each drawing, parts having the same configuration or function are designated by the same reference numerals. In describing this embodiment, duplicate descriptions of identical parts may be omitted or simplified as appropriate.

(buried pipes)
The buried pipe 1 (1a-1i) of the present disclosure includes a configuration for protecting the buried pipeline within the buried pipe 1 (1a-1i), thereby reducing the protection space compared to conventional configurations and enabling the buried pipeline to be protected even when it is difficult to ensure a sufficient distance (depth) from the road surface. FIG. 1 is a cross-sectional view showing an example configuration of a buried pipe 1 (1a) according to one embodiment. The buried pipe 1a protects various cables 9, such as optical fibers and power transmission lines, buried underground. The buried pipe 1a is installed in a conduit L that has been previously installed underground. As shown in FIG. 1, the buried pipe 1a includes multiple inner pipes 11, an outer pipe 12, and a protective member 13.

The inner tube (cable protection tube) 11 is a tubular member having a hollow portion 111 capable of accommodating the cable 9. The outer tube 12 is a tubular member that accommodates multiple inner tubes 11 and a protective member 13. As shown in FIG. 1 , the outer tube 12 has an inner surface T2 that contacts the outer surface T1 of each of the multiple inner tubes 11. Both the inner tube 11 and the outer tube 12 can be made of any material. For example, the inner tube 11 and the outer tube 12 may be made of synthetic resin materials such as calcium carbonate-containing rigid polyvinyl chloride, polyethylene, polypropylene, and ABS (acrylonitrile butadiene rubber styrene), or metals including steel. The outer tube 12 may be fixed underground using components such as joints.

The protective member 13 is a member provided in the space defined by the outer surfaces T1 of the multiple inner pipes 11 and the inner surface T2 of the outer pipe 12. The strength of the protective member 13 is greater than that of the inner pipes 11 and outer pipes 12. The protective member 13 may be made of any high-strength material, such as ceramics such as titanium boride or tungsten. In this embodiment, by providing the protective member 13, which is stronger than the inner pipes 11 and outer pipes 12, in the space adjacent to the outer surface T1 of the inner pipe 11, the cable 9 housed in the inner pipe 11 can be protected even if an excavation machine such as a cutter comes into contact with the buried pipe 1a. Therefore, even when it is difficult to ensure a sufficient distance between the ground surface G and the buried pipe 1a, it is possible to adequately protect the buried pipeline.

Furthermore, ceramics such as titanium boride are vulnerable to impact, and when they come into contact with an excavating machine such as a cutter, they may crack and scatter, resulting in a reduction in the protective performance of the cable 9. In this embodiment, the protective member 13 is confined in a space defined by the outer surfaces T1 of the multiple inner tubes 11 and the inner surface T2 of the outer tube 12. Therefore, even if the protective member 13 cracks, a reduction in protective performance due to the scattering of the protective member 13 can be prevented.

The multiple inner pipes 11 and outer pipes 12 may be molded separately, and the multiple inner pipes 11 may be housed within the outer pipe 12 together with the protective member 13 to form the buried pipe 1a. Alternatively, the multiple inner pipes 11 and outer pipes 12 may be molded as a single unit, and the protective member 13 may be inserted between the outer surface T1 of the multiple inner pipes 11 and the inner surface T2 of the outer pipe 12 to form the buried pipe 1a. This construction method of molding the inner pipes 11 and outer pipes 12 as a single unit beforehand and then inserting the protective member 13 to form the buried pipe 1a is easier to construct than the construction method of covering the protective member 13 with the resin that is used to form the inner pipes 11 and outer pipes 12.

While Figure 1 shows an example of a buried pipe 1a having three inner pipes 11, the number of inner pipes 11 included in the buried pipe 1 is arbitrary. For example, the buried pipe 1 may have two inner pipes 11 or four or more inner pipes 11. Figures 2A and 2B are cross-sectional views showing other configuration examples of a buried pipe 1 according to one embodiment. Figure 2A shows an example of a buried pipe 1b having two inner pipes 11. Figure 2B shows an example of a buried pipe 1c having four inner pipes 11.

The region 18 formed by the contact of the outer surfaces T1 of the multiple inner tubes 11 may be hollow, or may be filled with the material that constitutes the inner tube 11, thereby integrally molding the multiple inner tubes 11. Furthermore, while Figures 1, 2A, and 2B show an example in which the cross-sectional shapes of the inner tube 11 and outer tube 12 are circular, the cross-sectional shapes of the inner tube 11 and outer tube 12 are not limited to circular. For example, the cross-sectional shapes of the inner tube 11 and outer tube 12 may be circular, elliptical, polygonal, or a combination thereof. Furthermore, although Figures 1, 2A, and 2B show an example in which all of the multiple inner tubes 11 have the same size and shape, the size and shape of each inner tube 11 may differ.

Figures 1, 2A, and 2B show an example in which the protective member 13 has a shape that fills the space defined by the outer surfaces T1 of multiple inner pipes 11 and the inner surface T2 of the outer pipe 12, but the shape of the protective member 13 is arbitrary. Figures 3A to 3E are cross-sectional views showing an example of the protective member 13 of Figure 1.

The buried pipe 1d in Figure 3A is equipped with a protective member 13a having an arch-shaped (fan-shaped) cross section. The arch-shaped protective member 13a allows for a wide protection range.

The buried pipe 1e in Figure 3B is equipped with a protective member 13b having a pentagonal cross section. The pentagonal protective member 13b has a structure in which the tip of the arch-shaped protective member 13a is rounded off and the arch (arc) portion is made straight. The pentagonal protective member 13b allows for a protective range comparable in size to that of the arch-shaped protective member 13a.

The buried pipe 1f in Figure 3C is equipped with a protective member 13c having an L-shaped cross section. The L-shaped protective member 13f allows for a wider protective range. Furthermore, the L-shaped protective member 13f allows for a smaller volume of the protective member than the arch-shaped protective member 13a, making it possible to construct a protective structure more inexpensively than the arch-shaped protective member 13a.

The buried pipe 1g in Figure 3D is equipped with a protective member 13d having a rod-shaped cross section. The buried pipe 1h in Figure 3E is equipped with a protective member 13e having a circular cross section. The rod-shaped protective member 13d and the circular protective member 13e allow the volume of the protective member to be reduced, making it possible to construct a protective structure at low cost.

As illustrated in Figures 3A to 3E, when the protective member 13 does not fill the space defined by the outer surface T1 of the inner pipe 11 and the inner surface T2 of the outer pipe 12, an area 19 exists between the outer surface T1 of the inner pipe 11, the inner surface T2 of the outer pipe 12, and the protective member 13. Such an area 19 may be hollow, or may be filled with the material that constitutes the inner pipe 11 or the outer pipe 12, thereby molding multiple inner pipes 11 as a single unit, or molding multiple inner pipes 11 and outer pipes 12 as a single unit.

(Buried pipe connection structure)
Fig. 4 is a schematic diagram showing an example of a buried pipe connection structure 3 in which a plurality of buried pipes 1 are connected by joint members 2 and placed in an underground pipeline L. As shown in Fig. 4, a plurality of buried pipes 1 can be connected using joint members 2 that join the buried pipes 1, and installed in a pipeline L provided below the ground surface G. In the example of Fig. 4, the buried pipe connection structure 3 is installed in the pipeline L provided between manholes 60a and 60b.

As described in detail below, the coupling member 2 according to this embodiment includes an inner pipe 21 that can be fitted with the connection portion 151 of the buried pipe 1. The inner pipe 21 of the coupling member 2 has a fitting portion 212 that leaves a gap (clearance) between the inner pipe 21 and the connection portion 151 of the buried pipe 1 when the connection portion 151 is fitted. This allows the buried pipe 1 to be tilted to a certain angle relative to the coupling member 2 while remaining connected to the coupling member 2. Therefore, according to the connection structure 3 for the buried pipe 1 according to this embodiment, even if there is a bent section in the pipeline L, as shown in Figure 4, the buried pipeline can be adequately protected without installing a protective structure outside the pipeline L.

The buried pipe 1i that constitutes such a buried pipe connection structure 3 will be described with reference to Figures 5A to 5C. Figure 5A is a perspective view showing an example of an inner pipe structure 15 formed by integrally molding multiple inner pipes 11. Figure 5B is a side view of the inner pipe structure 15 of Figure 5A. Figure 5C is a cross-sectional view of the inner pipe structure 15 of Figure 5A taken along line A-A.

As shown in Figures 5A and 5C, in buried pipe 1i, three inner pipes 11 are integrally molded to form the inner pipe structure 15. As shown in Figure 5C, an outer pipe 12 having an inner surface T2 that contacts the outer surface T3 of the inner pipe structure 15 is provided around the inner pipe structure 15, and a protective member 13 is provided in the space defined by the outer surface T3 of the inner pipe structure 15 and the inner surface T2 of the outer pipe 12. In other words, buried pipe 1i comprises such an inner pipe structure 15, outer pipe 12, and protective member 13. As shown in Figures 5B and 5C, inner pipe structure 15 has connection portions 151 at both ends of inner pipe main body 155 that can be connected to coupling members 2 that join multiple components. The outer pipe 12 and protective member 13 are provided around the inner pipe main body 155.

Each connection portion 151 has a hollow portion 154 that communicates with the hollow portions 111 of the multiple inner pipes 11. The outer surface T3 of the connection portion 151 is provided with a concave-convex structure 152 that substantially engages with a fitting portion 212 provided on the inner pipe 21 of the coupling member 2 when the inner pipe 21 of the coupling member 2, described below with reference to Figures 6A to 6C, is fitted into the connection portion 151. The concave-convex structure 152 is structured to create a gap between the fitting portion 212 and the inner pipe 21 of the coupling member 2 when the inner pipe 21 of the coupling member 2 is fitted into the connection portion 151. The connection portion 151 is provided with a member 153 that receives the inner pipe 21 of the coupling member 2 and prevents further movement when the inner pipe 21 of the coupling member 2 is fitted into the connection portion 151.

Next, the joint member 2 that connects the buried pipe 1i will be described with reference to Figures 6A to 6C. Figure 6A is a perspective view showing an example of the inner pipe 21 of the joint member 2. Figure 6B is a front view of the inner pipe 21 of the joint member 2 of Figure 6A. Figure 6C is a cross-sectional view of the inner pipe 21 of the joint member 2 of Figure 6B at B-B. As shown in Figure 6B, the joint member 2 that joins the buried pipe 1 comprises an inner pipe 21, an outer pipe 22, and a protective member 23.

The inner pipe 21 is a tubular member having a hollow portion 211 that can fit into the connection portion 151 of the buried pipe 1. The outer pipe 22 is a tubular member that houses the inner pipe 21 and the protective member 23. As shown in FIG. 6B, the outer pipe 22 has an inner surface T5 that contacts the outer surface T4 of the inner pipe 21. Both the inner pipe 21 and the outer pipe 22 can be made of any material. For example, the inner pipe 21 and the outer pipe 22 may be made of synthetic resin materials such as calcium carbonate-containing rigid polyvinyl chloride, polyethylene, polypropylene, and ABS (acrylonitrile butadiene rubber styrene), or metals including steel.

The protective member 23 is a member provided in the space defined by the outer surface T4 of the inner pipe 21 and the inner surface T5 of the outer pipe 22. The strength of the protective member 23 is greater than that of the inner pipe 21 and the outer pipe 22. The protective member 23 may be made of any high-strength material, such as a ceramic such as titanium boride, or tungsten. By providing the protective member 23, which is stronger than the inner pipe 21 and the outer pipe 22, in the space adjacent to the outer surface T4 of the inner pipe 21, the cable 9 housed in the inner pipe 21 can be protected even if an excavation machine such as a cutter comes into contact with the joint member 2. Therefore, the buried pipeline can be adequately protected even in the joint member 2 area. Furthermore, similar to the buried pipe 1, the protective member 23 of the joint member 2 is confined in a space partitioned by the outer surface T4 of the inner pipe 21 and the inner surface T5 of the outer pipe 22, so even if the protective member 23 is cracked, it is possible to prevent a decrease in protective performance due to the protective member 23 flying off.

Furthermore, similar to the buried pipe 1, the inner pipe 21 and outer pipe 22 of the joint member 2 may be molded separately, and the inner pipe 21, together with the protective member 23, may be housed within the outer pipe 22 to form the buried pipe 1a. Alternatively, the inner pipe 21 and outer pipe 22 may be molded as a single unit, and the protective member 23 may be inserted between the outer surface T4 of the inner pipe 21 and the inner surface T5 of the outer pipe 22 to form the joint member 2. This construction method of molding the inner pipe 21 and outer pipe 22 as a single unit beforehand and then inserting the protective member 23 to form the joint member 2 is easier to construct than the construction method of forming the joint member 2 by covering the protective member 23 with the resin that is the material for the inner pipe 21 and outer pipe 22.

Furthermore, Figure 6B shows an example in which the protective member 23 has a shape that fills the space defined by the outer surface T4 of the inner pipe 21 and the inner surface T5 of the outer pipe 22, but as with the buried pipe 1, the protective member 23 of the joint member 2 may have any shape. For example, the protective member of the joint member 2 may have a shape similar to that of the protective member 13 of the buried pipe 1 described with reference to Figures 3A to 3E.

As shown in Figures 6A to 6C, the coupling member 2 has a fitting portion 212 on the inner surface S6 of the inner pipe 21. The fitting portion 212 approximately engages with the uneven structure 152 of the connection portion 151 when the connection portion 151 of the buried pipe 1 is fitted into the hollow portion 211 of the inner pipe 21. Here, the fitting portion 212 has a structure such that when the connection portion 151 of the buried pipe 1 is fitted, there is a gap between the fitting portion 212 and the uneven structure 152 of the connection portion 151. Therefore, the buried pipe 1 can be tilted up to a certain angle relative to the coupling member 2 while remaining connected to the coupling member 2.

Figure 7 shows an example in which two inner pipe structure portions 15 (of buried pipes 1) are connected by the inner pipe 25 of the joint member 2. In Figure 7, the outer pipe 12 and protective member 13 of the buried pipe 1, and the outer pipe 22 and protective member 23 of the joint member 2 are omitted. As shown in Figure 7, by providing a gap between the connection portion 151 of the buried pipe 1 and the inner pipe 25 of the joint member 2, the connection structure 3 of the buried pipe 1 can be bent.

(Method of installing buried pipes)
8A and 8B are schematic diagrams showing an example of a state in which a connection structure 3 for buried pipes 1, which is formed by connecting multiple buried pipes with coupling members, is disposed in an underground pipeline L. In the example of FIGS. 8A and 8B, the pipeline L is installed between manholes 60a and 60b. FIGS. 8A and 8B show an example in which there is a sufficient distance between the pipeline L and the ground surface G near the manholes 60a and 60b, but there is a shallow section along the way where the distance between the pipeline L and the ground surface G is small. In such a situation, methods for installing the connection structure 3 for buried pipes 1 in the shallow section include a method of excavating the area near the shallow section and a method of pushing the connection structure 3 through the manholes 60 (60a, 60b).

Figure 8A shows the process of installing a buried pipe by excavating the ground to expose the shallow section of the pipeline L and inserting the buried pipe connecting structure 3 through the opening L1 of the exposed pipeline L.

Figure 8B shows how buried pipe 1 is installed without excavating the ground. Figure 8B shows how buried pipe 1, previously connected by coupling member 2, is pushed into manhole 60a through opening 61a. When installing buried pipe connection structures by pushing them through manhole 60 (60a, 60b) in this way, the pipeline L on which the connection structure is installed may have a sufficient distance between the pipeline L and the ground surface G, and may include sections where a protective structure is not highly necessary. Therefore, as shown in Figure 8B, a buried pipe connection structure 3 with a protective structure (with protective members 13, 23) and a buried pipe connection structure 4 without a protective structure (without protective members 13, 23) may be combined to install the connection structure on pipeline L, depending on the distance between the pipeline L and the ground surface G. In this way, by combining and installing a buried pipe connecting structure 3 with a protective structure and a buried pipe connecting structure 4 without a protective structure depending on the need for the protective structure, it is possible to reduce the amount of protective materials 13, 23 used, which are generally expensive, and reduce installation costs.

Figure 9 is a flowchart showing the procedure for installing buried pipe 1 in pipeline L. The processing of each step may be performed by a worker.

In step S1, a buried pipe connection structure is constructed by combining a buried pipe with a protective structure (first buried pipe) and a buried pipe without a protective structure (second buried pipe) depending on the situation in which the pipeline L is laid. The buried pipe with a protective structure is the buried pipe 1 described with reference to Figures 1 to 3E, etc. The buried pipe without a protective structure includes multiple inner pipes with hollow portions capable of accommodating cables 9. For example, the buried pipe without a protective structure may be configured by removing the protective member 13 from the buried pipe 1. The buried pipe with a protective structure and the buried pipe without a protective structure may be connected by a joint member 2. However, in the connection structure 4 for buried pipes without a protective structure, they may be connected by a joint member that does not include the protective member 23. The combination of buried pipes with protective structures and buried pipes without protective structures may be determined based on the distance between the pipeline L and the ground surface G, etc., and depending on the situation, such as the need for protective structures in the pipeline L buried underground.

In step S2, the connecting structure constructed in step S1 is inserted and installed through the opening of the pipeline L. For example, a connecting structure 3 for buried pipes with a protective structure and a connecting structure 4 for buried pipes without a protective structure may be inserted through the opening 61a of the manhole 60a. The processing of the flowchart then ends.

The present disclosure is not limited to the above-described embodiments. Instead of executing the steps described in the flowcharts in chronological order as described, the steps may be executed in parallel or in a different order depending on the processing capabilities of the device executing each step, or as needed. Other modifications are possible without departing from the spirit of the present disclosure.

The following notes are further disclosed regarding the above embodiments.

(Additional note 1)
a plurality of inner tubes each having a hollow portion capable of accommodating a cable;
an outer tube containing the plurality of inner tubes and having an inner surface with a portion in contact with the outer surface of each of the plurality of inner tubes;
a protective member provided in a space defined by the outer surfaces of the inner pipes and the inner surface of the outer pipe;
Equipped with
The strength of the protective member is greater than that of the plurality of inner pipes and the outer pipe.
Buried pipe.
(Additional note 2)
The buried pipe according to claim 1, wherein the plurality of inner pipes and the outer pipe are integrally molded.
(Additional note 3)
3. The buried pipe according to claim 1, wherein the protective member has a shape that fills a space defined by the outer surfaces of the plurality of inner pipes and the inner surface of the outer pipe.
(Additional note 4)
3. The buried pipe according to claim 1 or 2, wherein the protective member has an arch-shaped, pentagonal, L-shaped, rod-shaped, or circular cross section.
(Additional note 5)
5. The buried pipe according to any one of claims 1 to 4, further comprising a connecting portion having a hollow portion that communicates with the hollow portions of the plurality of inner pipes and that can be connected to a joint member that joins a plurality of members.
(Additional note 6)
A joint member for joining buried pipes,
an inner pipe having a hollow portion that can be fitted into the connection portion of the buried pipe;
an outer tube containing the inner tube and having an inner surface with a portion in contact with the outer surface of the inner tube;
a protective member provided in a space defined by an outer surface of the inner pipe and an inner surface of the outer pipe;
Equipped with
The strength of the protective member is greater than that of the inner pipe and the outer pipe,
the inner pipe has a fitting portion that has a gap between it and the connecting portion when the connecting portion is fitted to the inner pipe;
Joint material.
(Supplementary Note 7)
A buried pipe connection structure comprising a buried pipe and a joint member that joins the buried pipe,
The buried pipe is
a plurality of first inner tubes each having a hollow portion capable of accommodating a cable;
a first outer tube that houses the plurality of first inner tubes and has an inner surface having a portion that contacts the outer surface of each of the plurality of first inner tubes;
a first protective member provided in a space defined by outer surfaces of the plurality of first inner tubes and an inner surface of the first outer tube;
a connecting portion connectable to the coupling member and having a hollow portion communicating with the hollow portions of the plurality of first inner pipes;
Equipped with
the first protective member has a strength greater than that of the plurality of first inner tubes and the first outer tube;
The coupling member is
a second inner pipe having a hollow portion that can be fitted into the connection portion of the buried pipe;
a second outer tube containing the second inner tube and having an inner surface with a portion in contact with the outer surface of the second inner tube;
a second protective member provided in a space defined by an outer surface of the second inner tube and an inner surface of the second outer tube;
Equipped with
the second protective member has a strength greater than that of the second inner pipe and the second outer pipe;
the second inner pipe has a fitting portion that has a gap between it and the connecting portion when the connecting portion is fitted thereto;
Buried pipe connection structure.
(Supplementary Note 8)
a first buried pipe comprising: a plurality of first inner pipes each having a hollow portion capable of accommodating a cable; an outer pipe accommodating the plurality of first inner pipes and having an inner surface having a portion in contact with the outer surface of each of the plurality of first inner pipes; and a protective member provided in a space defined by the outer surfaces of the plurality of first inner pipes and the inner surface of the outer pipe, wherein the strength of the protective member is greater than that of the plurality of first inner pipes and the outer pipe;
a second buried pipe including a plurality of second inner pipes each having a hollow portion capable of accommodating the cable;
The method for installing buried pipes comprises connecting the above-mentioned pipes to the pipes buried underground in accordance with their conditions and inserting them through the opening of the pipes.

1 (1a to 1i) Buried pipe 11 Inner pipe 111 Hollow part 12 Outer pipe 13, 13a to 13e Protective member 15 Inner pipe structure part 151 Connection part 152 Uneven structure 153 Member 154 Hollow part 155 Inner pipe main body part 18 Region 19 Region 2 Joint part 21 Inner pipe 212 Fitting part 22 Outer pipe 23 Protective member 252 Uneven parts 3, 4 Buried pipe connection structure 9 Cables 60a, 60b Manholes 61a, 61b Opening G Ground surface L Pipeline L1 Openings T1, T3, T4 Outer surface T2, T5, T6 Inner surface

Claims (8)

a plurality of inner tubes each having a hollow portion capable of accommodating a cable;
an outer tube containing the plurality of inner tubes and having an inner surface with a portion in contact with the outer surface of each of the plurality of inner tubes;
a protective member provided in a space defined by the outer surfaces of the inner pipes and the inner surface of the outer pipe;
Equipped with
The strength of the protective member is greater than that of the plurality of inner pipes and the outer pipe.
Buried pipe. The buried pipe described in claim 1, wherein the multiple inner pipes and the outer pipe are integrally molded. A buried pipe as described in claim 1, wherein the protective member has a shape that fills the space defined by the outer surfaces of the multiple inner pipes and the inner surface of the outer pipe. The buried pipe described in claim 1, wherein the protective member has an arch-shaped, pentagonal, L-shaped, rod-shaped, or circular cross-section. The buried pipe described in claim 1 further comprises a connecting portion having a hollow portion that communicates with the hollow portions of the multiple inner pipes and that can be connected to a joint member that joins multiple members. A joint member for joining buried pipes,
an inner pipe having a hollow portion that can be fitted into the connection portion of the buried pipe;
an outer tube containing the inner tube and having an inner surface with a portion in contact with the outer surface of the inner tube;
a protective member provided in a space defined by an outer surface of the inner pipe and an inner surface of the outer pipe;
Equipped with
The strength of the protective member is greater than that of the inner pipe and the outer pipe,
the inner pipe has a fitting portion that has a gap between it and the connecting portion when the connecting portion is fitted to the inner pipe;
Joint material. A buried pipe connection structure comprising a buried pipe and a joint member that joins the buried pipe,
The buried pipe is
a plurality of first inner tubes each having a hollow portion capable of accommodating a cable;
a first outer tube that houses the plurality of first inner tubes and has an inner surface having a portion that contacts the outer surface of each of the plurality of first inner tubes;
a first protective member provided in a space defined by outer surfaces of the plurality of first inner tubes and an inner surface of the first outer tube;
a connecting portion connectable to the coupling member and having a hollow portion communicating with the hollow portions of the plurality of first inner pipes;
Equipped with
the first protective member has a strength greater than that of the plurality of first inner tubes and the first outer tube;
The coupling member is
a second inner pipe having a hollow portion that can be fitted into the connection portion of the buried pipe;
a second outer tube containing the second inner tube and having an inner surface with a portion in contact with the outer surface of the second inner tube;
a second protective member provided in a space defined by an outer surface of the second inner tube and an inner surface of the second outer tube;
Equipped with
the second protective member has a strength greater than that of the second inner pipe and the second outer pipe;
the second inner pipe has a fitting portion that has a gap between it and the connecting portion when the connecting portion is fitted thereto;
Buried pipe connection structure. a first buried pipe comprising: a plurality of first inner pipes each having a hollow portion capable of accommodating a cable; an outer pipe accommodating the plurality of first inner pipes and having an inner surface having a portion in contact with the outer surface of each of the plurality of first inner pipes; and a protective member provided in a space defined by the outer surfaces of the plurality of first inner pipes and the inner surface of the outer pipe, wherein the strength of the protective member is greater than that of the plurality of first inner pipes and the outer pipe;
a second buried pipe including a plurality of second inner pipes each having a hollow portion capable of accommodating the cable;
The method for installing buried pipes comprises connecting the above-mentioned pipes to the pipes buried underground in accordance with their conditions and inserting them through the opening of the pipes.