JP7296585B2 - Underground cable removal method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an underground cable removal method for removing an underground cable passing through a trough.

BACKGROUND ART In recent years, underground wiring has been popularized from the viewpoint of consideration for landscape and safety in cities. In underground wiring, troughs and conduits are buried in the ground, and power cables, communication cables, etc. (hereinafter referred to as underground cables) are laid inside them. Underground cables are removed when they deteriorate over time or when they are no longer needed.

As a method for removing an underground cable, Patent Document 1, for example, discloses a method for removing an underground cable. In the underground cable removal method of Patent Document 1, first, a power cable passing through a pipeline is cut inside a manhole. Then, a propulsion pipe (synonymous with a cutting pipe) is fitted to the cable from the cut end, and this propulsion pipe is pushed into the pipe line by a propulsion device while being spliced, and the fixed part is peeled off with a bit at the tip of the leading propulsion pipe. After that, the cable is pulled out from the conduit. According to Patent Document 1, it is possible to efficiently remove an underground cable that is stuck to the inner surface of a conduit and cannot be pulled out.

Japanese Patent Application Laid-Open No. 2001-224112

Since the underground cables laid in the pipeline are placed between adjacent manholes, work can be interrupted immediately simply by covering the manholes. On the other hand, if the underground cable is laid in the trough, the road surface is excavated and the underground cable is removed. Therefore, when the work is interrupted, backfilling must be performed, and when the work is resumed, the backfilling material must be dug up. For this reason, a great deal of time and effort was required when removing the underground cable laid in the trough.

In view of the above problems, the present invention provides an underground cable that can efficiently remove an underground cable laid in a trough and can greatly reduce the time and labor required for the work. The object is to provide a cable removal construction method.

In order to solve the above problems, a representative configuration of the underground cable removal method according to the present invention is an underground cable removal method for removing an underground cable passing through a trough, in which a plurality of short metal pipes are rotated. A scraping pipe having a flexible pipe connected by a movable joint and a scraper attached to the tip of the flexible pipe is used to excavate the road surface to expose the end surface of the trough, and the guide pipe is attached to the trough at one end. It is characterized in that it is arranged so that the other end is continuous with the end surface and is located on the road surface, the periphery of the guide pipe is backfilled, and the drilling pipe is rotated and propelled into the trough from the road surface through the guide pipe.

According to the above configuration, the underground cable is separated from the soil in the trough by the scraper attached to the flexible tube of the drilling tube by rotating the drilling tube and propelling it through the trough. This allows the underground cable to be removed from the trough. At this time, in the above configuration, not the entire road surface is excavated, but a portion of the road surface that exposes the end surface of the trough is excavated. As a result, the range to be backfilled when the work is interrupted is dramatically narrowed. Therefore, the work of removing the underground cable laid in the trough can be efficiently performed, and the time and labor required when the work is interrupted can be greatly reduced.

Further, according to the above configuration, the other end of the guide pipe is positioned on the road surface, and the periphery thereof is backfilled. As a result, when resuming work, the drilling tube can be inserted from the guide tube. Therefore, it is possible to greatly reduce the time and labor required when resuming work.

In the underground cable removal method, when the work is interrupted, it is preferable to remove the portion of the flexible pipe exposed to the road surface and cover the open end of the guide pipe with a lid. By covering the open end of the guide pipe with the lid in this manner, the work site can be paved temporarily. Therefore, it becomes possible for a vehicle or the like to run on the road surface on which the lid is placed after the removal work is interrupted.

In the underground cable removing method, it is preferable to suck the soil excavated by the drilling pipe from the flexible pipe. As a result, the soil around the drilling pipe is removed so that the drilling pipe can be propelled better.

ADVANTAGE OF THE INVENTION According to the present invention, an underground cable removal construction method is provided that can efficiently perform the work of removing an underground cable laid in a trough and can greatly reduce the time and labor required for the work. can do.

It is a figure explaining the work spot to which the underground cable removal construction method of this embodiment is applied. It is a figure explaining the excavation pipe for underground cable removal concerning this embodiment, and its propulsion device. It is a figure explaining a flexible tube. It is a figure explaining a scraper. It is a typical sectional view explaining the removal construction method of the underground cable concerning this embodiment. It is a typical sectional view explaining the removal construction method of the underground cable concerning this embodiment. It is a figure explaining the variation of the removal construction method of this embodiment.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a diagram illustrating a work site to which the underground cable removal construction method of this embodiment is applied. As shown in FIG. 1(a), at a work site 10, a trough 12 is buried in the ground under a road surface 10a, and an underground cable 14 is laid inside the trough. As shown in FIG. 1( b ), the trough 12 is filled with an embedding material 18 (for example, soil) so that the underground cable 14 is covered with the embedding material 18 . A lid 16 is provided on the upper surface of the trough 12 . In the underground cable removal construction method of this embodiment, the underground cable 14 passing through the inside of the trough 12 is removed.

FIG. 2 is a diagram illustrating a drilling pipe for removing an underground cable (hereinafter referred to as drilling pipe 100) and a propulsion device 200 thereof according to the present embodiment. In this embodiment, the drilling pipe 100 is propelled while rotating in the trough 12 by the propulsion force from the propulsion device 200 . As shown in FIGS. 2A and 2B , the propulsion device 200 includes a motor 210 that rotates the drilling tube 100 and a hydraulic cylinder 220 that propels the drilling tube 100 . The drilling tube 100 includes a flexible tube 110 and a scraper 120 .

3A and 3B are diagrams illustrating the flexible tube 110. FIG. As shown in FIG. 3A, the flexible tube 110 is configured by connecting a plurality of metal short tubes 112a, 112b, 112c, and 112d. By connecting the flexible pipes 110, which are multi-node pipes, the trough 12 can be drilled to an arbitrary length (several tens of meters to several hundreds of meters).

Joints 114a, 114b, and 114c, which are connecting portions of the short pipes 112a-112d, are rotatable and can be bent as shown in FIG. 3(b). Among the plurality of short pipes 112a to 112d that constitute the flexible pipe 110, the short pipe 112a that is first inserted into the trough 12 has a similar flexible pipe 110 or a scraper 120 attached near its tip. A mounting portion 116 is formed. On the other hand, among the plurality of short pipes 112a to 112d forming the flexible pipe 110, the short pipe 112d that is inserted into the trough 12 last is formed with a mounting groove 118 that is connected to the mounting portion 116. As shown in FIG.

FIG. 4 is a diagram illustrating the scraper 120. FIG. The scraper 120 shown in FIG. 4 is attached to the distal end of the short pipe 112a that is first inserted into the pipeline among the plurality of short pipes 112a to 112d that constitute the flexible pipe 110. As shown in FIG. A mounting groove 122 connected to the mounting portion 116 is formed at the rear end of the scraper 120 .

Particularly in the drilling tube 100 of this embodiment, the scraper 120 is beak-shaped with two symmetrical triangular tips 124 . As a result, the scraper 120 at the tip of the drilling pipe 100 can easily bite between the underground cable 14 and the buried material 18 (soil) in the trough 12, so that the underground cable 14 can be pulled out and removed more reliably. becomes possible.

If the tip of the scraper 120 is one (an overall oblique cut shape), the scraping tube 100 is biased when the tip bites in, making it difficult to rotate. As a result, it bites in with good balance and can be rotated smoothly. In addition, if the tip has a large number of serrations, the outer sheath of the cable is cut, causing leakage of cooling oil from the OF cable. can be prevented.

Further, in this embodiment, the scraper 120 is tapered 126 on the inside of the triangular tip 124 . This makes it easier for the scraper 120 to bite between the underground cable 14 and the buried material 18 in the trough 12, so that the above effects can be enhanced.

5 and 6 are schematic cross-sectional views for explaining a method for removing the underground cable 14 according to this embodiment. In the trough 12 shown in FIG. 5(a), the underground cable 14 generates heat during power transmission. The underground cable 14 tends to extend and meander due to the rise in temperature. The embedding material 18 filled in the trough 12 plays a role of a heat transfer material for dissipating heat, and also plays a role of a support member for suppressing meandering. On the other hand, since the buried material 18 is compressed while being heated, it solidifies in the trough 12 , and furthermore, the solidified buried material 18 sticks to the underground cable 14 . As a result, the frictional resistance increases, making it difficult to pull out the underground cable 14 .

In the underground cable removal method (hereinafter referred to as removal method) of this embodiment, first, the road surface 10a shown in FIG. 5A is excavated, and the end surface 12a of the trough 12 is exposed as shown in FIG. . Next, as shown in FIG. 5(c), the guide pipe 20 is arranged so that one end is continuous with the end face 12a of the trough 12 and the other end is positioned above the road surface 10a (outside the ground), The perimeter of the tube 20 is backfilled.

Subsequently, as shown in FIG. 6( a ), the drilling pipe 100 is inserted into the trough 12 from the road surface 10 a through the guide pipe 20 , and the underground cable 14 is inserted inside the drilling pipe 100 . Next, the drilling pipe 100 is rotated by the motor 210 of the propulsion device 200 and propelled by the propulsive force of the hydraulic cylinder 220 . As a result, the scraper 120 attached to the flexible tube 110 of the drilling tube 100 bites while rotating between the buried material in the trough 12 and the underground cable 14, and the underground cable 14 is fixed in the trough 12. It is separated from the buried material (soil). Therefore, it becomes possible to remove the underground cable 14 from the trough 12 .

At this time, in the removal method of the present embodiment, the underground cable 14 is removed by excavating a portion of the road surface 10a to the extent that the end face 12a of the trough 12 is exposed, rather than excavating the entire road surface 10a. can be done. For this reason, the range to be refilled when the work is interrupted is dramatically narrowed. Therefore, the work of removing the underground cable 14 laid in the trough 12 can be efficiently performed, and the time and labor required when the work is interrupted can be greatly reduced.

Moreover, in the removal construction method of this embodiment, the other end of the guide pipe 20 is positioned on the road surface 10a, and the periphery thereof is backfilled. As a result, when resuming work, the cutting tube 100 can be inserted from the guide tube 20 . Therefore, it is possible to greatly reduce the time and labor required when resuming work.

Especially in the removal method of this embodiment, as shown in FIG. cover. As a result, the work site 10 is temporarily paved. Therefore, it becomes possible for a vehicle or the like to run on the road surface 10a on which the lid 30 is placed after the removal work is interrupted. Then, as shown in FIG. 6(c), if the lid 30 is removed, the work can be resumed quickly.

FIG. 7 is a diagram for explaining variations of the removal method of this embodiment. In FIG. 7, the suction tube 302 of the suction device 300 (vacuum car) is connected to the propulsion device 200 and communicated with the flexible tube 110 of the drilling tube 100 . Then, the soil excavated by the drilling pipe 100 is sucked from the flexible pipe 110 via the suction pipe 302 by the suction device 300 . As a result, the soil around the drilling pipe 100 is removed, so that the drilling pipe 100 can be propelled more satisfactorily.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the claims, and these also belong to the technical scope of the present invention. Understood.

INDUSTRIAL APPLICABILITY The present invention can be used for an underground cable removal method for removing an underground cable passing through a trough.

DESCRIPTION OF SYMBOLS 10... Work site 10a... Road surface 12... Trough 12a... End surface 14... Underground cable 18... Burying material 20... Guide pipe 30... Lid 100... Drilling pipe 110... Flexible pipe 112a... Short pipe 112b Short pipe 112c Short pipe 112d Short pipe 116 Mounting portion 118 Mounting groove 120 Scraper 122 Mounting groove 200 Propulsion device 210 Motor 220 Hydraulic cylinder , 300... Suction device, 302... Suction tube

Claims (3)

In the underground cable removal method for removing the underground cable passing through the trough,
Using a scraping tube having a flexible tube in which a plurality of metal short tubes are connected by rotatable joints and a scraper attached to the tip of the flexible tube,
excavating the road surface to expose the end surface of the trough;
A guide pipe is arranged so that one end is continuous with the end face of the trough and the other end is positioned on the road surface,
backfilling around the guide tube;
An underground cable removal method characterized by rotating and propelling the drilling pipe from the road surface through the guide pipe into the trough. 2. The underground cable removal method according to claim 1, wherein when the work is interrupted, the portion of the flexible pipe exposed to the road surface is removed, and the open end of the guide pipe is covered with a lid. 3. An underground cable removing method according to claim 1, wherein the soil excavated by said drilling pipe is sucked from said flexible pipe.

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