JP2021126022A - Repair structure and repair method of underground conduit - Google Patents

Abstract

To provide a repair structure and a repair method of an underground conduit that surely prevents the immersion of water spread through an underground from a repair part of a conduit line by using a concrete foundation for installation to a ground of a concrete layer extended in a planar, for example, a power facility.SOLUTION: A repair structure of an underground conduit of the present invention has a structure that an open part B in which a damage portion of a conduit line 1 is expanded is coated with a self fusion tape 3 in order to repair the damage portion of the conduit line 1 embedded into an underground while housing an electric cable 2 into an inner part, and the part coated with the self fusion tape 3 of the conduit line 1 is thickly covered by an underground part 4a of the concrete foundation 4 on which a power facility is installed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a structure for repairing a pipeline in which a cable such as a power cable is housed inside and buried in the ground, and a method for repairing the pipeline.

In the foundation work for installing a power facility such as a capacitor type voltage transformer (also called Potential Device or PD) on the ground, there is a case where a trial excavation is performed to confirm the buried position of the power cable line. In the trial excavation, for example, after carefully digging the place where the power cable is expected to be buried by hand digging, if a protective plate for protecting the power cable comes out, use a shovel car if necessary. The position of the protective plate is shifted or removed, but at that time, there is a problem that the power cable line is accidentally damaged by the excavator teeth of the shovel car or the shifted protective plate.

Conventionally, for example, the following method has been adopted as a repair method for preventing the intrusion of water and the inflow of earth and sand into the power cable line when the power cable line is damaged. Was being done. That is, the damaged part of the power cable line is cut open and the presence or absence of damage and the damaged state of the power cable are visually checked. If the power cable is not damaged, the inside of the line is cleaned and then the power is supplied. It was repaired by wrapping a self-bonding tape around the opening formed by cutting open the damaged part of the cable pipeline.

However, if the damaged part of the power cable line is cut open, the opening area of the opening will be wider than that of the damaged part, so repairing so that the opening is covered with self-bonding tape is not sufficient. After returning the power cable line to the ground, water that has permeated from the ground around the power cable line may infiltrate into the power cable line through the opening.

In this regard, Patent Document 1 proposes a structure in which the power cable pipeline is filled with concrete in advance and the periphery of the power cable in the pipeline is solidified with concrete.

Further, in Patent Document 2, the damaged part of the pipeline is confirmed, the repair range of the pipeline is set, a part of the repair range of the pipeline is removed, and a half-split sleeve is provided in the repair range of the removed pipeline. After insertion, a pipeline repair method has been proposed in which concrete is placed on the outer periphery of the portion where the half-split sleeve of the pipeline is attached.

Japanese Unexamined Patent Publication No. 10-56712 JP-A-2007-170511

However, in the proposal of Patent Document 1, the concrete is arranged in the pipeline and is not used to prevent water from entering the pipeline from the damaged portion of the pipeline. Moreover, Patent Document 1 is an invention for constructing a new pipeline, not an invention for repairing a damaged existing pipeline.

On the other hand, Patent Document 2 aims at repairing a pipeline in which a cable is housed and buried in the ground, and a method of placing concrete on the outer periphery of the pipeline is adopted. However, in the figure showing the fifth concrete placement from the top of FIG. 1 (b) of Patent Document 2, the concrete is only arranged in a limited range of the outer circumference of the pipeline, and such If the thickness is centered on the concrete pipeline, water may penetrate to the repaired part of the pipeline due to cracks in the concrete, so be sure to prevent water from entering from the repaired part of the pipeline. It is difficult. Moreover, in the pipeline repair method of Patent Document 2, since the middle part of the pipeline is completely cut off and the half-split sleeve is inserted, the annular shape between the conduit and the half-split sleeve inserted into the conduit is formed. If there is a gap in any of the joints, there is a high possibility that the infiltrated water will infiltrate into the pipeline or fluid concrete will invade the pipeline when the concrete is placed. ..

The present invention utilizes a flat concrete layer, for example, a concrete foundation for installation of a power facility on the ground, to ensure that water that has penetrated the ground does not infiltrate from the repaired portion of the pipeline. The main task is to provide a repair structure and repair method for the buried pipeline.

In order to achieve the above object, in the present invention, in the repair structure of the underground pipeline for accommodating the cable inside and repairing the damaged portion of the pipeline buried in the ground, the damaged portion of the pipeline is It is assumed that the portion of the pipeline covered with the repair material is covered with a concrete layer extending in a plane while being covered with the repair material. The concrete layer may be used as a concrete foundation for installing an electric power facility on the ground, and the underground portion of the concrete foundation may cover a portion covered with a repair material for the pipeline.

The repair material is, for example, a self-bonding tape, a fiber-reinforced plastic (also referred to as Fiber-Reinforced Plastics, also referred to as FRP; the same applies hereinafter), and a member made of acrylic resin, and is desired to have a waterproof function. The electric power facility is, for example, a capacitor type voltage transformer (Potential Device, PD). The damaged part of the pipeline also includes an opening in which the damaged part of the pipeline is widened so that the inside can be seen.

In such a method of repairing an underground pipeline, a repair material covering step of covering a damaged portion of the pipeline with a repair material and a concrete layer extending in a plane are covered with the repair material of the pipeline. It is a step of placing a concrete layer. Prior to the repair material covering step, an opening forming step may be further provided to widen the damaged portion of the pipeline into an opening in which the inside can be seen. Then, covering the damaged portion of the pipeline with a repair material means, for example, wrapping the damaged portion of the pipeline around the pipeline so as to cover the damaged portion of the pipeline with self-bonding tape. Alternatively, by combining a pair of semi-cylindrical bodies in a half-split state, the pipe is fixed to the pipe so as to cover the damaged portion with a pipe member having a tubular shape that can be attached to the outer periphery of the pipe.

As a result, a concrete layer that spreads widely in the horizontal direction centering on the underground pipeline and has a large depth from the ground surface to the ground, for example, a concrete foundation for installing an electric power facility on the ground, is used as a repair material for the pipeline. Since it covers the part covered with, it is prevented that the water in the ground also penetrates the concrete layer or the concrete foundation and reaches the part covered with the repair material of the pipeline. Moreover, by covering the damaged part of the pipeline with a repair material having a waterproof function before placing the concrete layer or concrete foundation, fluid concrete can be removed from the damaged part into the pipeline when the concrete is placed. It is possible to prevent intrusion.

As described above, according to the present invention, in order to install a concrete layer, for example, an electric power facility, which spreads widely in the horizontal direction around an underground pipeline and has a large depth from the ground surface to the ground. Because the concrete foundation of the underground covers the part covered with the repair material of the underground pipeline, the underground water also penetrates the concrete layer or the concrete foundation and reaches the part covered with the repair material of the pipeline. Since this is avoided, even if the damaged portion of the pipeline is not sufficiently covered with the repair material, it is possible to reliably prevent water from entering the underground pipeline.

Further, according to the present invention, since the damaged part of the pipeline is covered with the repair material before the concrete foundation is placed, the fluid-like concrete invades the pipeline from the damaged part at the time of placing the concrete. It is also possible to prevent this.

The structure of the present invention in which the portion of the power cable pipeline buried in the ground where the opening (including the damaged portion) is repaired by covering the self-bonding tape is covered with the underground portion of the concrete foundation. It is shown. It is an enlarged view from the side which repaired the opening (including the damaged part) with the self-bonding tape of the power cable line, and further covered the opening with a concrete foundation. It is an enlarged cross-sectional view of the portion which repaired the opening (including the damaged part) with the self-bonding tape of the power cable line, and further covered the opening with a concrete foundation, as seen from the front. (A) is an explanatory diagram showing a test drilling process performed when newly installing a capacitor type voltage transformer, and (b) is an explanatory diagram showing a test drilling process, and (b) damages an underground power cable pipeline during the test drilling. It is explanatory drawing which shows the process of repairing the damaged part with a repair material and the process of expanding a hole at the time of having done it, and (c) is concrete of the transformer for a capacitor type voltage transformer by placing concrete in the hole. It is explanatory drawing which shows the process of covering the opening (including the damaged part) of a power cable with a foundation. It is explanatory drawing which shows the process of covering a relatively large opening (including a damaged part) of a pipeline with a conduit member composed of two semi-cylindrical constituent members as a repair material. It is explanatory drawing which shows the process of covering a relatively large opening (including a damaged part) of a pipeline with a conduit member, and then winding a self-bonding tape from the upper side thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, as an example of the embodiment of the present invention, the portion of the power cable line 1 buried in the ground 100 where the damaged portion is repaired by covering the self-bonding tape 3 is the concrete foundation 4. The structure covered by the underground part is shown. Hereinafter, the repair structure of the pipeline 1 will be described with reference to FIGS. 2 to 4.

As shown in FIG. 2, the power cable line 1 is a bellows-shaped tubular body made of a material such as hard polyethylene, and inside the cable line 1, as shown in FIGS. 1 and 3. , A plurality of (three in this embodiment) power cables 2 are accommodated. The damaged part A of the electric power cable line 1 shown by the one-point chain line in FIG. 2 digs down a place where the electric power cable line 1 is expected to be buried by, for example, hand digging, and protects the power cable line 1. After the protective plate 5 (shown in FIG. 4A) has come out, when the shovel car (not shown) is used to shift or remove the protective plate 5, the shovel car excavator It is caused by hitting teeth or a shifted protective plate. Although the pipeline of the power cable 2 is used, the present invention can be applied to a pipeline that houses a cable other than the power cable 2 inside.

The self-bonding tape 3 is one of the repair materials used to prevent water from entering the power cable line 1 from the damaged portion and earth and sand from flowing into the cable line 1. The self-bonding tape 3 is formed of, for example, butyl rubber or the like, and has a structure in which the front surface and the back surface of the tape 3 are in close contact with each other by being wound around an object while being stretched. Along with this, as shown in FIGS. 2 and 3, the self-bonding tape 3 has a damaged portion A of the power cable line 1 or an opening B in which the damaged portion A is widened (two points in FIG. 2). In order to cover (indicated by a chain wire), it is used in the form of being wound around the outer circumference of the power cable line 1 a plurality of times.

In this embodiment, the concrete foundation 4 is a foundation for installing three capacitor-type voltage transformers 6, 6 and 6 on the ground. That is, as shown in FIG. 1, the concrete foundation 4 has a substantially rectangular parallelepiped foundation body 4a having a wall thickness and three projecting upwards from the foundation body 4a according to the number of capacitor-type voltage transformers 6. It is a flat concrete layer composed of protruding portions 4b, 4b, and 4b. The entire foundation body 4a of the concrete foundation 4 is 100 in the ground, and the protruding portions 4b, 4b, and 4b have a lower portion in the ground 100 and an upper portion protruding from the ground surface 101. The thickness of the basic body 4a of the present invention is thicker than the thickness of the conventional basic body shown by the broken line in FIG. In addition, in order to improve the waterproof performance of the concrete foundation 4, an inorganic cement crystal growth material may be mixed with the concrete of the base body to improve the concrete foundation 4.

The capacitor-type voltage transformer 6 installed on the upper surface of the protruding portion 4b of the concrete foundation 4 is an example of an electric power facility installed on the ground, and uses the principle of capacitor partial voltage to shift the primary voltage to the secondary side. This is for transforming to a required low voltage, but since it is known here, the description thereof will be omitted. The electric power cable line 1 and the electric power cable 2 passing through the electric power cable line 1 are not for supplying electric power to the capacitor type voltage transformer 6, and are irrelevant to the capacitor type voltage transformer 6.

A power cable in a concrete foundation 4 for installing such a capacitor-type voltage transformer 6 on the ground, in which an opening B (including a damaged portion A) is covered with a self-bonding tape 3 and repaired. The outer circumference of the pipeline 1 is thickly covered over a wide area (range of 360 degrees) by the foundation main body 4a which is an underground portion. That is, as shown in FIG. 1, the depth of the foundation body 4a of the concrete foundation 4 from the ground surface 101, the width in the horizontal direction which is the radial direction of the pipeline 1, and the thickness upward from the deepest portion. In any of the above cases, the thickness and width of the self-bonding tape 3 are secured so that the opening B (including the damaged portion A) is covered with the repaired power cable line 1 so that water does not permeate.

As a result, it is surely prevented that the water that has permeated the ground also permeates the concrete foundation 4 and reaches the power cable line 1, so that the repair with the self-bonding tape 3 is supposed to be against inundation. Even if it is not sufficient, it is possible to prevent the permeated water from entering the conduit 1 through the opening B (including the damaged portion A) covered with the self-bonding tape 3. ..

Next, when a damaged portion A occurs in the power cable line 1 due to the above-mentioned circumstances, the power cable line 4 is used to install the condenser type voltage transformer 6 on the ground. The method of repairing No. 1 will be described from the process of drilling for confirming the burial position of the pipeline 1 by using FIGS. 4 (a) to 4 (c).

If there is a possibility that the power cable line 1 is buried in the planned installation site of the capacitor type voltage transformer 6, the power cable line buried in the ground is as shown in FIG. 4 (a). A trial moat is performed to dig a hole 6a for confirming the position of the road 1. If the power cable line 1 is accidentally damaged during the drilling, the steps shown in FIGS. 4 (b) and 4 (c) are started.

First, the circumference of the power cable line 1 is dug down to form an upwardly open hole 6b for inserting the fluid concrete for the concrete foundation 4, as shown in FIG. 4 (b). That is, the hole 6a formed in the test moat is expanded to the outer shape of the concrete foundation 4. At this time, it is desirable that the damaged portion A of the power cable line 1 is located at the center of the hole 6b as viewed from above. By forming the hole 6b in this way, the damaged portion A is exposed so that the following repair can be easily performed even in the power cable line 1.

Next, the damaged portion A of the power cable line 1 exposed in the hole 6b is cut open, and the presence or absence of damage and the damaged state of the power cable 2 are visually confirmed (opening forming step), and the power cable 2 is used. If there is no damage to the power cable line 1, after cleaning the inside of the line 1, an opening formed by cutting open the damaged part of the power cable line 1 as shown in FIGS. 2, 3, and 4 (b). Repair is performed by wrapping the self-bonding tape 3 around B a plurality of times to cover the opening B (damaged portion A) (repair material coating step).

Further, after flattening the lower surface of the hole 6b using a predetermined device, the electric power cable line 1 is moved upward while filling the electric power cable line 1 and particularly the repair portion A thereof with fluid concrete. By driving according to a predetermined procedure while flowing into the hole 6b so as to move to, the repair portion of the power cable line 1 in the foundation main body 4a of the underground portion shown in FIG. 4 (c). The concrete foundation 4 is covered with water (concrete layer casting step). Since the opening B (damaged portion A) of the power cable pipeline 1 is covered with the self-bonding tape 3, concrete flows into the pipeline 1 from the opening B (damaged portion A). It can be prevented from being stowed.

In the description of the above embodiment, the case where the self-bonding tape 3 is used as the repair material has been shown, but the present invention is not necessarily limited to this, and for example, a fiber reinforced plastic, a member made of acrylic resin, or the like may be used as the repair material. good. Further, as shown in FIGS. 5 and 6, the pipeline member 8 may be used as a repair material. The configuration of the pipeline member 8 and a part of the steps of the repair method using the pipeline member 8 will be described below with reference to FIGS. 5 and 6.

As shown in FIG. 5, the pipeline member 8 has a bellows-shaped tubular shape that can be attached to the outer circumference of the power cable pipeline 1 by combining a pair of semi-cylindrical bodies 8a and 8b in a half-cracked state. It has a bellows-shaped cylinder with both sides open). That is, the inner diameter of the pipeline member 8 is slightly larger than the inner diameter of the power cable pipeline 1.

As shown in FIG. 6, the pipeline member 8 is covered with the opening B (damaged portion A) of the pipeline 1 (the inner surface of the pipeline member 8 is in contact with the outer surface of the pipeline 1). After being attached to the outer periphery of No. 1, the conduit 1 and the conduit member 8 are wound with the self-bonding tape 3 a plurality of times to repair the pipe. By using this pipeline member 8, even if the opening B (damaged portion A) of the pipeline 1 is large, it can be repaired by covering the opening B (damaged portion A).

1 Electric power cable pipeline (pipeline)
2 Power cable (cable)
3 Self-bonding tape (repair material)
4 Concrete foundation 6 Capacitor type voltage transformer (electric power equipment)
8 Pipeline member (repair material)
8a semi-cylindrical body 8b semi-cylindrical body
100 Underground A Damaged part B Opening

Claims (6)

In the repair structure of underground pipelines that accommodate cables inside and repair damaged parts of pipelines buried underground.
An underground buried pipeline characterized in that a damaged portion of the pipeline is covered with a repair material and a portion covered with the repair material of the pipeline is covered with a concrete layer extending in a plane. Repair structure. The concrete layer is a concrete foundation for installing an electric power facility on the ground, and the underground portion of the concrete foundation covers a portion covered with a repair material for the pipeline. The repair structure of the underground pipeline according to Item 1. In the method of repairing underground pipelines, which accommodates cables inside and repairs damaged parts of pipelines buried underground,
A repair material covering step for covering the damaged part of the pipeline with a repair material, and
A concrete layer placing step in which a concrete layer extending in a plane is placed so as to cover a portion of the pipeline covered with the repair material.
A method of repairing an underground pipe, which is characterized by having. The repair of an underground pipeline according to claim 3, further comprising an opening forming step for expanding the damaged portion of the pipeline to an opening whose inside can be seen before the repair material covering step. Method. 3. The method of repairing the underground buried pipeline described. Covering the damaged part of the pipeline with a repair material means that the damaged portion is covered with a tubular member that can be attached to the outer periphery of the pipeline by combining a pair of semi-cylindrical bodies in a semi-cracked state. The method for repairing an underground buried pipeline according to claim 3 or 4, wherein the pipe is fixed to the pipeline.

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