JPH0792186B2 - How to repair underground pipes - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for externally repairing a pipe buried in the ground.

BACKGROUND ART Underground buried pipes are buried in soil, for example, for guiding gas, water, sewage, hot water and steam, and for guiding power lines and telephone lines. In order to repair such a portion of the underground buried pipe that is leaking fluid, a portion where corrosion is reduced in thickness, or a portion where paint is corrosion-resistant, a soil is repaired, for example, as shown in FIG. The pit 2 is excavated in 1 to expose the pipe 3, the portion of the pipe 3 to be repaired is covered with a sealant 4 such as urethane rubber, and then the pit 2 is backfilled.

In another prior art, after excavating the above-mentioned vertical hole 2 to expose the pipe 3, the portion of the pipe 3 to be repaired is cut and replaced.

In each of such prior arts, a lot of labor is required to excavate the pit 2, and when the place where the pit 2 is formed is a road or the like, it becomes an obstacle to traffic, and moreover, such a road. It will result in the destruction of ground structures such as. Moreover, when the pipe 3 is partially cut and replaced as described above, it is necessary to stop the supply of the fluid or to interrupt the supply of the electric power and the communication, which causes a serious problem.

Another prior art is a method of preventing leakage from the inner surface of the underground buried pipe. For that purpose, a method of lining a flexible lining tube made of synthetic resin on the inner surface of the pipe, and a method of atomizing the inner surface of the pipe. There is a method of spraying the sealing agent, and a method of applying the sealing agent in a liquid state on the inner surface of the pipe. In each of these prior arts, a pit must be excavated from the ground in order to expose the underground buried pipe, which causes the same problem as described above. Moreover, the above-mentioned prior art in which the sealant is injected into the underground buried pipe has a problem that only a small leak point of the fluid can be repaired.

Problem to be Solved by the Invention An object of the present invention is to provide a method for repairing an underground buried pipe, which enables reliable repair of the underground buried pipe by a simple operation.

MEANS FOR SOLVING THE PROBLEMS The present invention allows a plurality of pipes to be passed through soil in the vicinity of a repaired portion of an underground pipe to pump a fluid to at least one of the pipes so that the remaining pipes A method for repairing an underground buried pipe, characterized in that the soil in the vicinity of the repaired portion is discharged together with the fluid, and then the sealant is supplied from at least one of the pipe bodies to cover the repaired portion with the sealant.

Action According to the present invention, a plurality of pipes are passed through the soil in the vicinity of the repaired part of the underground buried pipe, the fluid is pumped to at least one of the pipes, and the remaining pipes together with the fluid form the repaired part of the repaired part. Discharge nearby soil. As a result, the soil surrounding the repaired part of the underground pipe is discharged to the ground, and the vicinity of the repaired part becomes a cavity. Then, the sealant is supplied from at least one of the tubular bodies. As a result, even when the sealing agent flows into the cavity and the soil hardly permeates the sealing agent such as clay, the repaired portion can be covered with the sealing agent. The sealant may be a liquid, or may be sprayed to cover the perimeter of the repair. After injecting the sealant into this spray and solidifying it,
A leak check can be made and then the liquid sealant can be prevented from penetrating the soil when the repaired part is covered by injecting a liquid sealant.

Moreover, as described in connection with the above-mentioned prior art, it is not necessary to excavate a pit in a road or the like, and the underground buried pipe is used to shut off the fluid to be transported or to be installed in the underground buried pipe. It is no longer necessary to cut off power lines and communication lines such as telephones.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention.

The soil 7 is provided with an underground buried pipe 8 such as a steel pipe for transporting gas. The leaking portion of the pipe 8, the corrosion-reduced portion,
Alternatively, repairs such as anti-corrosion defects in the paint can be repaired in accordance with the present invention. In order to perform the repair, first, the buried position of the underground buried pipe 8 is detected from the ground. For this detection, a so-called pipe locator or the like, which generates an AC magnetic field on the ground and magnetically detects it, is used.

After the buried location of the underground buried pipe 8 is detected, first, as shown in FIG. 2, relatively small holes 10 and 11 are formed near the repaired portion of the underground buried pipe 8 by using a drill 12. . This hole 10 may be formed not only by using a drill 12 but also by driving a rod into the soil 7 and pulling out the rod, or by suctioning the soil to form the holes 10 and 11. The holes 10 may be formed by other means. Hole 10,11
Are formed in this embodiment.

After the holes 10 and 11 are formed, a pair of pipes are placed in the holes 10 and 11.
Insert 13 and 14, respectively. As shown in FIG. 3, the tube body 13 has an outer cylinder 15 and an inner cylinder 16 having a diameter smaller than that of the outer cylinder 15, and is configured in a double tube shape. The outer cylinder 15 and the inner cylinder 16 are airtightly separated by a partition member 17. This partition member 17
A communication hole 18 is formed in the outer cylinder 15 below the outer cylinder 15. A communication hole 19 is formed in the outer cylinder 15 above the partition member 17.
The space between the inner peripheral surface of the outer cylinder 15 and the outer peripheral surface of the inner cylinder 16 is
Connected to. The other tubular body 14 has the same structure, and corresponding parts are designated by the same reference numerals with a subscript a.

Next, as shown in FIG. 4, the inner cylinder 16 of the pipe body 13 has a supply source.
Water is pumped from 28, and the inner cylinder 16a of the other tube body 14 is connected to the suction pump 23. The tubes 20, 20a may also be connected to the suction pump 23. The water from the inner cylinder 16 flows from the communication hole 18 to the vicinity of the repaired portion of the underground buried pipe 8, and the water enters the communication hole 18a of the pipe body 14 together with the soil surrounding the repaired portion, It is discharged from the suction pump 23 to the ground through the inner cylinder 16a. As a result, the area near the repaired portion of the underground buried pipe 8
29 is a cavity, and the repaired part is exposed in the cavity 29.
Although water is pumped from the supply source 28 in the above-described embodiment, other liquids may be used, or a gas such as air may be used. Mixed fluids may be used.

In order to detect the state of gas leakage from the repaired part of the underground buried pipe 8, as shown in FIG. 5, the inner cylinder 16 of the pipe body 13 is detected.
For this, air or an inert gas such as nitrogen gas is pumped from the supply source 22. The inner cylinder 16a of the pipe body 14 is a suction pump 23.
The gas from the suction pump 23 is measured by the flow meter 24, and the concentration of the gas leaking from the underground buried pipe 8 is detected by the detection circuit 25. In this way, the flow rate and concentration of the gas leaking from the underground buried pipe 8 can be measured, and the leak state can be examined on the ground. The state of leakage can also be confirmed by the change with time of this concentration.

When the underground buried pipe 8 transports a liquid, a liquid colored in a predetermined color is pressure-fed to the underground buried pipe 8 and the suction flow rate of the liquid sucked by the suction pump 23 and the component analysis of the liquid Moreover, the state of liquid leakage from the underground buried pipe 8 can be known based on the coloring state and the like.

The air or the inert gas is also pressure-fed from the pipe 20 of the pipe body 13, and the inlet of the suction pump 23 is, as described above, the inner cylinder of the pipe body 14.
Not only 16a, but also tube 20a may be connected.

In order to know the state of leakage of gas or liquid from the repaired portion of the underground buried pipe 8, an optical fiber 31 is inserted into the inner cylinder 16 of the pipe body 13 as shown in FIG. The tip portion 32 of the fiber 31 is exposed from the communication hole 18 of the pipe body 13 to the region 29 which is a cavity. The image pickup device 33 provided on the ground is connected to the optical fiber 31, and the image pickup means 33 shows the condition of the outer periphery of the repaired portion exposed in the region 29 of the underground buried pipe 8 facing the tip 32 of the optical fiber 31. You can look it up on the ground.

Next, referring to FIG. 1, the sealant is pressure-fed from the supply source 26 to the inner cylinder 16 of the pipe body 13. At this time, the inner cylinder 16a of the tubular body 14 is
Connect to suction pump 23. The tubes 20, 20a of the tubes 13, 14 may also be connected to the suction pump 23. As a result, the sealant flows from the inner cylinder 16 of the pipe body 13 through the communication hole 18 into the vacant region 29, and solidifies by covering the repaired portion of the underground buried pipe 8. The gas leaking from the underground buried pipe 8 is
It is sucked by the suction pump 23 from the communication hole 18a through the inner cylinder 16a. As a result, the sealant smoothly jets into the region 29, and the repaired portion of the underground pipe 8 can be reliably surrounded by the sealant. The amount of sealing agent supplied is 8 underground pipes.
Appropriately select according to the state of gas leakage.

In the above-described embodiment, the suction pump 23 is used in FIG. 1, but as another embodiment, as shown in FIG. 7, when the sealant is supplied from the sealant supply source 26, The region 16 may be brought to atmospheric pressure by exposing the cylinder 16a to the atmosphere. Also by this, the sealant that is pressure-fed from the supply source 26 to the inner cylinder 16 can smoothly flow into the region 29 from the communication hole 18 and reliably cover the repaired portion of the underground buried pipe 8.

The pressure for supplying the sealant is equal to or higher than the pressure of the gas transported by the underground buried pipe 8,
The sealing agent can surely reach the repaired portion of the underground buried pipe 8 and its vicinity.

Although the sealant may be a slurry-like liquid as in the above-mentioned embodiment, as another embodiment, the sealant may be sprayed in the region 29 in a spray form. As a result, the outer periphery of the repaired portion of the underground buried pipe 8 is covered with the sealant, and the soil in the area 29 is solidified with the sealant. After this solidification, a further liquid sealant may be injected, which prevents the liquid sealant from penetrating the soil.

When the viscosity of the sealant is relatively low, the repaired portion of the underground buried pipe 8 is an anchorage type pipe joint, and the outer peripheral surface of one pipe end and the inner peripheral surface of the other pipe end are In the case where the structure has a structure in which the yarn and lead are packed in between to achieve airtightness, the sealing agent penetrates into the pipe joint to enhance the airtight performance of the pipe joint.

As the sealant, there are organic materials and inorganic materials,
As the organic material, there are a thermoplastic resin and a thermosetting resin. As the thermoplastic resin, polyethylene, vinyl chloride resin, polypropylene, styrene resin, ABS resin, polyvinyl alcohol, acrylic resin, acrylonitrile-styrene resin, vinylidene chloride resin, AAS (ASA) resin, AES resin (weather resistance, impact resistance Resin), fibrin derivative resin, thermoplastic polyurethane, polyvinyl butyral,
Examples include poly-4-methylpentene-1 and polybutene-1. As the thermosetting resin, unsaturated polyester resin, epoxy resin, phenol resin, urea resin, melamine resin, diallyl phthalate resin, silicone resin,
For example, polyurethane. Examples of the inorganic material include water glass.

For example, when an epoxy resin is used as a sealant, a bisphenol A type epoxy resin is used as a main component, which has a viscosity of 10,000 cps (temperature 25 ° C), and an aliphatic polyamine as a curing agent, which has a viscosity of 2,000. cps
(Temperature 25 ° C.), the main agent and the curing agent are mixed in a weight ratio of 100 to 60, and the curing time is 3 hours.

The invention can be implemented not only in connection with underground pipes for transporting gas, but also in connection with underground pipes for transporting water, hot water, steam, etc., as well as power lines and telephones. It can also be implemented in connection with an underground pipe in which a communication line such as a line is inserted. As the sealant, for example, the above-mentioned ones can be used, depending on the type of soil such as sand, clay, mountain soil, etc., and can be used for drying and humid conditions, and for permanent and emergency purposes. Can be used according to each application.

Effect As described above, according to the present invention, it is not necessary to excavate a relatively large vertical hole in the soil in which the underground buried pipe is buried, which simplifies the work and When a place where such underground pipes are buried is a road etc., there is no traffic obstacle, there is no danger of destroying ground structures such as roads, and noise and vibration are generated again. Can be suppressed. Furthermore, the underground buried pipe can be repaired while it is still in use, that is, while the fluid is being transported, or with the power line and communication line inserted, and the underground buried pipe can be repaired. There is no need to cut it, which is convenient.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view showing a step of forming holes 10 and 11 in soil 7, and FIG.
4 is a cross-sectional view showing a process for forming a region 29 that is a cavity, and FIG. 5 is a process for examining a gas leakage condition from a repaired portion of the underground buried pipe 8. 6 is a sectional view for explaining the step of examining the outer peripheral surface of the repaired portion of the underground buried pipe 8 in the region 29 using the optical fiber 31, and FIG. 7 is another embodiment of the present invention. In the area
FIG. 8 is a cross-sectional view showing the step of feeding the sealant from the supply source 26 to 29, and FIG. 8 is a cross-sectional view of the prior art. 7 ... Soil, 8 ... Underground pipe, 10,11 ... hole, 13,14 ...
… Tube, 23 …… Suction pump, 26 …… Sealant supply source, 28
...... Water supply source

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area E03F 7/00 F16L 1/038 H02G 1/06

Claims (1)

[Claims] 1. A plurality of pipes are passed through the soil in the vicinity of the repaired part of an underground buried pipe, and a fluid is pumped to at least one of the pipes so that the remaining pipes together with the fluid near the repaired part. A method for repairing a buried underground pipe, comprising discharging soil, and then supplying a sealant from at least one of the pipes to cover the repaired part with the sealant.