Buried pipes and methods for protecting them

Abstract

An underground pipe 1 comprises a inner pipe 11 that can house a cable 9, a protective member 12 that is disposed on the outer circumference of the inner pipe 11, and an outer pipe 10 that houses the protective member 12 and the inner pipe 11. The strength of the protective member 12 is higher than that of the inner pipe 11 and the outer pipe 10.

Description

[Technical Field]

[0001] The present disclosure relates to buried pipes and methods for protecting buried pipes. [Background technology]

[0002] It is known that buried pipes are used to house various cables such as optical fibers and power transmission lines when they are buried underground. When buried pipes are formed by burying them underground, such as under roads, there is a high risk that the buried pipes will be damaged by excavation machines such as cutters during road construction work in shallow sections where the soil cover, which is the depth from the ground surface to the buried pipe, cannot be sufficiently secured.

[0003] In order 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 ground surface and the buried pipeline (Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-355758 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-143355 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-180166 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional configurations, a certain amount of space is required above the buried pipe, and it is sometimes difficult to ensure a sufficient distance from the ground surface to the buried pipe due to the structure of the terrain or strata, etc., and therefore the buried pipeline cannot be adequately protected.

[0006] The object of the present disclosure is to provide a buried pipe and a method for protecting the buried pipe that can adequately protect the buried pipeline even when it is difficult to ensure a distance from the ground surface to the buried pipe. [Means for solving the problem]

[0007] The buried pipe according to one embodiment includes an inner pipe capable of accommodating a cable, a protective member disposed on the outer periphery of the inner pipe, and an outer pipe accommodating the protective member and the inner pipe, and the strength of the protective member is higher than that of the inner pipe and the outer pipe. The surface of the protective member is coated with a coating material. .

[0008] A method for protecting a buried pipe according to one embodiment is a method for protecting a buried pipe having an outer pipe, and includes the steps of: arranging a protective member having a strength greater than that of the inner pipe and the outer pipe around an outer periphery of an inner pipe capable of accommodating a cable; and accommodating the inner pipe, with the protective member disposed around its outer periphery, in the outer pipe. The surface of the protective member is coated with a coating material. . [Effects of the Invention]

[0009] According to the present disclosure, even when it is difficult to ensure a sufficient distance from the ground surface to the buried pipe, it is possible to appropriately protect the buried pipe. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of a buried pipe according to one embodiment. [Figure 2] 2 is a side view showing an example of the configuration of the protective member of FIG. 1. FIG. [Figure 3] FIG. 10 is a cross-sectional view showing another example of the configuration of the buried pipe according to the embodiment. [Figure 4] 4 is a side view showing an example of the configuration of the protective member of FIG. 3. FIG. [Figure 5] FIG. 2 is a side view illustrating an example of the configuration of a protective member according to an embodiment. [Figure 6] FIG. 6 is an enlarged view of the protective member of FIG. 5. [Figure 7]4 is a cross-sectional view showing an example in which a multiple cable housing portion is housed in the inner pipe of FIG. 3. FIG. [Figure 8A] FIG. 1 is a cross-sectional view showing an example of an outer tube configured as a split tube. [Figure 8B] FIG. 1 is a cross-sectional view showing an example of an outer tube configured as a split tube. [Figure 9A] FIG. 1 is a cross-sectional view showing an example of an inner tube configured as a split tube. [Figure 9B] FIG. 1 is a cross-sectional view showing an example of an inner tube configured as a split tube. [Figure 10] 1 is a flowchart showing the steps of a buried pipe protection method according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, parts having the same configuration or function are denoted by the same reference numerals. In the description of this embodiment, duplicated descriptions of the same parts may be omitted or simplified as appropriate.

[0012] The present disclosure provides a configuration for protecting a buried pipeline within a buried pipe 1 (1a, 1b, 1c), thereby reducing the protection space compared to conventional configurations and making it possible to protect the buried pipeline 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, that are buried underground. FIG. 2 is a side view showing an example configuration of a protective member 12a of FIG. 1. The buried pipe 1a includes an inner pipe 11, a protective member 12a, and an outer pipe 10.

[0013] The inner pipe (cable protection pipe) 11 is a tubular member capable of accommodating the cable 9. The outer pipe 10 is a tubular member that accommodates the protective member 12a and the inner pipe 11. Both the inner pipe 11 and the outer pipe 10 can be made of any material. For example, the inner pipe 11 and the outer pipe 10 may be made of synthetic resin materials such as calcium carbonate-containing hard polyvinyl chloride, polyethylene, polypropylene, and ABS (acrylonitrile butadiene rubber styrene), or metals including steel. The outer pipe 10 may be fixed underground using members such as joints.

[0014] The protective member 12a is a member disposed on the outer periphery of the inner pipe 11. The strength of the protective member 12a is greater than that of the inner pipe 11 and the outer pipe 10. The protective member 12a may be made of any material with high strength, for example, ceramic such as titanium boride, or tungsten. In this manner, in this embodiment, by disposing the protective member 12a, which is stronger than the inner pipe 11 and the outer pipe 10, on the outer periphery 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 if it is difficult to ensure a sufficient distance from the ground surface to the buried pipe 1a, it is possible to appropriately protect the buried pipeline.

[0015] Furthermore, the surface of the protective member 12a may be coated with a coating material 13. The coating material 13 may be made of any material capable of protecting the surface of the protective member 12a. For example, the material of the coating material 13 may be an insulating resin such as FRP (Fiber-Reinforced Plastics), a rubber material such as water-expandable rubber or SBR (Styrene-Butadiene Rubber), or an elastomer. By coating the surface of the protective member 12a with the coating material 13 in this way, even if the protective member 12a is cracked, the protective member 12a can be prevented from scattering.

[0016] Furthermore, it is known that when a conductive ceramic comes into contact with a conductive metal, a potential difference occurs between the conductive ceramic and the metal, causing corrosion of the metal. Therefore, when at least one of the inner tube 11 and the outer tube 10 is metal and the protective member 12a is conductive ceramic, the coating material 13 may be made of an insulating material. This can insulate the protective member 12a, which is a conductive ceramic, from the inner tube 11 and the outer tube 10, which are metals, preventing corrosion of the inner tube 11 or the outer tube 10 due to contact between the two. For example, using the aforementioned FRP resin or rubber material for the coating material 13 can effectively prevent corrosion of the inner tube 11 or the outer tube 10.

[0017] Although FIGS. 1 and 2 show an example in which the entire surface of the inner pipe 11 is covered with the protective member 12a, there may be a region of the surface of the inner pipe 11 that is not covered with the protective member 12a. FIG. 3 is a cross-sectional view showing an example of the configuration of a buried pipe 1b in which a protective member 12b is partially disposed on the surface of the inner pipe 11. FIG. 4 is a side view showing an example of the configuration of the protective member 12b of FIG. 3. FIGS. 3 and 4 show an example in which the protective member 12b includes multiple rod-shaped bodies 15 arranged parallel to the longitudinal direction of the inner pipe 11. Although FIGS. 3 and 4 show an example in which the protective member 12b includes four rod-shaped bodies 15, the number of rod-shaped bodies 15 may be any number. FIG. 5 is a side view showing another example of the configuration of the protective member 12c. FIG. 6 is an enlarged view of the protective member 12c of FIG. 5. FIGS. 5 and 6 show an example in which the protective member 12c includes multiple rectangular bodies 16 arranged in a lattice pattern (shroud stripe).

[0018] As shown in FIGS. 3 to 6, a portion of the outer periphery of the inner pipe 11 may be uncovered by the protective members 12b and 12c. Generally, the protective member 12, which is made of ceramic or the like, is more expensive than the inner pipe 11 or the outer pipe 10. By partially disposing the protective members 12b and 12c on the surface of the inner pipe 11, even if the protective member 12 is expensive, it is possible to reduce the cost of the buried pipe 1 and adequately protect the buried pipeline. While FIGS. 3 to 6 show an example in which the protective member 12 is partially disposed on the surface of the inner pipe 11, the arrangement of the protective member 12 is not limited thereto. For example, the protective member 12 may be a plurality of annular (ring) bodies disposed at intervals on the surface of the inner pipe 11.

[0019] Although FIGS. 1 and 3 show examples in which the inner pipe 11 directly accommodates the cable 9, the inner pipe 11 may also accommodate another structure capable of accommodating the cable 9. FIG. 7 is a cross-sectional view showing an example in which a multi-cable accommodation section 14 is accommodated within the inner pipe 11 of FIG. 3. The multi-cable accommodation section 14 has multiple accommodation spaces 17 for accommodating the cable 9, respectively. FIG. 7 shows an example in which the multi-cable accommodation section 14 has three accommodation spaces 17. The multi-cable accommodation section 14 may be made of any material. For example, the multi-cable accommodation section 14 may be made of a synthetic resin material such as calcium carbonate-containing rigid polyvinyl chloride, polyethylene, polypropylene, or ABS (acrylonitrile butadiene rubber styrene), or a metal material including steel. By accommodating the multi-cable accommodation section 14 with multiple accommodation spaces 17 within the inner pipe 11 in this way, it is possible to accommodate multiple cables 9 separately into multiple bundles. 7, the multi-cable housing 14 may be configured so that the first member 14a and the second member 14b can be separated at the boundary 14c. This allows the first member 14a and the second member 14b to be separated to house the cables 9, making it easier to house the cables 9 in the multi-cable housing 14. The number of housing spaces 17 provided in the multi-cable housing 14 and the position and shape of the boundary 14c in the multi-cable housing 14 are arbitrary and are not limited to those exemplified in FIG.

[0020] While FIGS. 1, 3, and 7 show examples in which the outer pipe 10 and the inner pipe 11 all have a continuous circular cross section, the outer pipe 10 and the inner pipe 11 may have a split pipe structure in which the upper and lower halves can be separated. FIGS. 8A and 8B are cross-sectional views showing an example of an outer pipe 10 configured as a split pipe. The outer pipe 10 has an upper section 10a and a lower section 10b that can be separated. FIGS. 9A and 9B are cross-sectional views showing an example of an inner pipe 11 configured as a split pipe. The inner pipe 11 has an upper section 11a and a lower section 11b that can be separated. By using such a split pipe structure for the outer pipe 10 and the inner pipe 11, the installation of the buried pipe 1 becomes easier and partial replacement is possible during repairs, thereby improving workability. The split pipe structure of the outer pipe 10 and the inner pipe 11 may have any structure other than one in which the upper and lower sections of the buried pipe 1 can be separated, as long as it allows for easy access to and removal of contents. For example, the split pipe structure of the outer pipe 10 and the inner pipe 11 may be a structure that allows the buried pipe 1 to be separated in a vertical plane. Also, the split pipe structure of the outer pipe 10 and the inner pipe 11 may be a structure that allows the buried pipe 1 to be separated in all parts, or may be a structure that allows the buried pipe 1 to be separated only in a part of the buried pipe 1.

[0021] 10 is a flowchart showing the steps of one embodiment of a method for protecting a buried pipe 1. The protection method according to this embodiment constructs a protective structure for protecting a cable 9 inside the buried pipe 1, thereby reducing the protection space compared to conventional configurations and making it possible to protect the buried pipe 1 even when it is difficult to ensure a sufficient distance (depth) from the road surface.

[0022] In step S1, the protective members 12 (12a, 12b, 12c) are arranged around the inner pipe 11. For example, as shown in FIGS. 1 and 2, if the protective member 12a has a cylindrical shape with a hollow portion, the inner pipe 11 may be housed in the hollow portion of the protective member 12. For example, as shown in FIGS. 3 and 4, if the protective member 12b is composed of multiple rod-shaped bodies 15, the multiple rod-shaped bodies 15 may be arranged parallel to each other in the longitudinal direction on the surface of the inner pipe 11. For example, as shown in FIGS. 5 and 6, if the protective member 12c has multiple rectangular bodies 16 arranged in a lattice pattern, the multiple rectangular bodies 16 may be arranged by wrapping them around the outer periphery of the inner pipe 11.

[0023] In step S2, the inner pipe 11 with the protective members 12 (12a, 12b, 12c) arranged therein is placed inside the outer pipe 10. For example, the inner pipe 11 with the protective members 12 (12a, 12b, 12c) arranged therein is inserted into the hollow portion of the outer pipe 10.

[0024] In step S3, the cable 9 is housed inside the inner pipe 11. Then, the processing of the flowchart ends.

[0025] By performing the above steps, it is possible to configure the buried pipe 1 having a protective structure for protecting the cable 9. Note that the order of the above steps may be reversed in practice.

[0026] In each embodiment of the present disclosure, by constructing a protective structure inside the buried pipe 1, it is possible to protect the cable 9 from excavators such as cutters without the need to provide other components between the ground surface and the buried pipe 1. Therefore, the buried pipe 1 can be used even in cases where it is difficult to ensure a separation from the road surface, and it is possible to save space above the buried pipe 1.

[0027] The present disclosure is not limited to the above-described embodiments, and modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0028] 1a,1b,1c Buried pipe 9 Cable 10 outer tube 11 Inner tube 12a, 12b, 12c Protective members 13 Coating materials 14 Multi-cable housing 15 Rod-shaped body 16 Rectangular body

Claims

1. an inner tube capable of accommodating a cable; a protective member disposed on the outer periphery of the inner pipe; an outer tube that accommodates the protective member and the inner tube; Equipped with The strength of the protective member is greater than that of the inner pipe and the outer pipe, The surface of the protective member is coated with a coating material. Buried pipe.

2. At least one of the inner tube and the outer tube is made of metal, the protective member is a conductive ceramic; The coating material is an insulating material. The buried pipe according to claim 1.

3. The buried pipe according to claim 2 , wherein the coating material is an insulating resin or a rubber material.

4. The buried pipe according to claim 1 , wherein a part of the outer periphery of the inner pipe is not covered by the protective member.

5. The buried pipe according to claim 4 , wherein the protective member comprises a plurality of rod-shaped bodies arranged in parallel to the longitudinal direction of the inner pipe, or a plurality of rectangular bodies arranged in a lattice pattern.

6. A method for protecting a buried pipe having an outer pipe, comprising: a step of disposing a protective member having a strength greater than that of the inner pipe and the outer pipe around an outer periphery of an inner pipe capable of accommodating a cable; a step of housing the inner pipe, the outer surface of which is disposed the protective member, in the outer pipe; Including, The surface of the protective member is coated with a coating material. Methods for protecting buried pipes.

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