JPH0792187B2 - 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 thinned, 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 pit 2 is formed on 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, the inner surface of the pipe is lined with a flexible lining tube made of synthetic resin, and the inner surface of the pipe is atomized. 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 spray the underground 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 forms a single hole from the ground in the soil near the repaired portion of the underground buried pipe, and forms two vertically extending passages in the hole. One of the features is that the fluid is pumped from one of the passages, the soil of the repaired portion is discharged together with the fluid from the other, and then the sealant is supplied from at least one of the passages to cover the repaired portion with the sealant. It is a method of repairing medium buried pipes.

Operation According to the present invention, a single hole is formed from the ground in the soil near the repaired portion of the underground buried pipe, and two vertically extending passages are formed in the hole. These two passages may be formed by a double tubular tube inserted in the hole, or the two passages may be formed by other configurations. The fluid is pumped from one of these two passages, and the soil in the vicinity of the repaired portion is discharged from the other passage together with the fluid. 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. Thereafter, the sealant is supplied from at least one of the passages. As a result, even if the sealing agent flows into the cavity and the soil hardly penetrates the sealing agent such as clay, the repaired portion can be surely 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 in this spray form and solidifying it, it is possible to confirm the leakage.When the repaired part is covered by injecting the liquid sealant next, the liquid sealant penetrates into the soil. Can be prevented.

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 fluid to be transported is shut off by an underground pipe or the power line installed in the underground pipe. Also, it is not necessary to cut off 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. Repaired parts such as leaking parts, corrosion-reduced parts, or anti-corrosion defects in the coating of this pipe 8 can be repaired according to the 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 position of the underground buried pipe 8 is detected, first, as shown in FIG. 2, a relatively small single hole 10 is formed near the repaired portion of the buried underground pipe 8 by using a drill 9. To do. This hole 10 may be formed not only by using the drill 9 but also by driving a rod into the soil 7 and pulling out the rod, or by suctioning the soil to form the hole 10. The holes 10 may be formed by any means.

After forming the hole 10, the hole is formed as shown in FIG.
Insert the tube 13 into the tube 10. Then, another flexible tube body 14 is inserted into the tube body 13. Next, water is pumped from the supply source 28 to the pipe body 14. Inner peripheral surface of tube 13 and tube 14
The space between the outer peripheral surface and the outer peripheral surface is connected to the suction pump 23 via the pipe 15 and is sucked. The water from the pipe body 14 flows near the repaired portion of the underground buried pipe 8, and the water flows between the inner peripheral surface of the pipe body 13 and the outer peripheral surface of the pipe body 14 together with the soil surrounding the repaired portion. It enters the space between them and is discharged from the pipe 15 from the suction pump 23 to the ground. As a result, the inclined area 29 near the repaired portion of the underground buried pipe 8 becomes a cavity, and the repaired portion is sprayed into 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 portion of the underground buried pipe 8, the gas in the region 29 is sucked from the pipe body 14 by the suction pump 23, as shown in FIG. Suction pump
The gas from 23 is measured by a flow meter 24, and the underground pipe 8
The concentration of the gas leaking from the sensor 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.

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 pipe body 13 as shown in FIG. A region 29 where the tip portion 32 connects the lower end portion of the pipe body 13 to the cavity
To face. The imaging device 33 provided on the ground is connected to the optical fiber 31, and the underground buried pipe 8 facing the tip portion 32 of the optical fiber 31.
The condition of the outer periphery of the repaired portion exposed in the area 29 can be checked on the ground by the image pickup means 33.

Next, referring to FIG. 1, the pipe body 14 is inserted into the pipe body 13, the supply source 26 is connected to the pipe body 14, and the sealing agent is fed under pressure. At this time, the space between the inner peripheral surface of the tube body 13 and the outer peripheral surface of the tube body 14 is connected to the suction pump 23 via the tube 16.
As a result, the sealant easily flows from the pipe body 14 into the hollowed region 29 and solidifies by covering the repaired portion of the underground buried pipe 8. The gas leaking from the underground pipe 8 is
It is sucked by the suction pump 23 from the space between the inner peripheral surface of the tube body 13 and the outer peripheral surface of the tube body 14 through the tube 16. Therefore, the sealing agent can be smoothly jetted into the region 29, and the repaired portion of the underground buried pipe 8 can be reliably surrounded by the sealing agent. The supply amount of the sealing agent is appropriately selected according to the gas leakage state of the underground buried pipe 8.

Thereafter, the pipe body 14 is taken out, and as shown in FIG. 6, the sealing agent is filled from the region 29 to the pipe body 13. In this way, it is possible to surely prevent gas leakage in the repaired portion of the underground buried pipe 8 for repair.

In the above-mentioned embodiment, the suction pump 23 is used in FIG. 1, but as another embodiment, the suction pump 23 is not used, and the space between the inner peripheral surface of the pipe body 13 and the outer peripheral surface of the pipe body 14 is not used. May be released to the atmosphere to bring the region 29 to atmospheric pressure. Also by this, the sealant which is pressure-fed from the supply source 26 to the pipe body 14 can smoothly flow into the region 29 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 to enable the sealant to hermetically cover the repaired part of the underground buried pipe 8. To do.

FIG. 7 is a sectional view of another embodiment of the present invention. Soil 7
From above, the position of the underground pipe 8 is detected by using a so-called pipe locator using electromagnetic force, and a hole 35 is formed using a self-propelled excavator 34 thereat,
The cavity 36 can be formed near the repaired portion of the underground buried pipe 8.

FIG. 8 is a sectional view of another embodiment of the present invention. Tube 37
Has an outer cylinder 38 and an inner cylinder 39, and an end portion 39a of the inner cylinder 39 has an outer cylinder 3
It projects downward from the end portion 38a of 8. End 38 of outer cylinder 38
An end plate 40 is fixed to a, and a plurality of communication holes 41 are formed in this end plate 40. A hole 10 is formed as in the step shown in FIG. 2 and the tube body of FIG.
37 is inserted, and then water is pressure-fed between the inner peripheral surface of the outer cylinder 38 and the outer peripheral surface of the inner cylinder 39 by the water supply source 28 shown in FIG.
The inner cylinder 39 is connected to the suction pump 23. This allows the end plate 40
Water can be ejected from the communication hole 41 and the soil in the repaired area 29 of the underground buried pipe 8 can be sucked and discharged from the end 39a of the inner cylinder 39 together with water. In this way, after the region 29 becomes a cavity, for example, a sealant is pumped into the inner cylinder 39, and the repaired portion of the underground buried pipe 8 is covered with the sealant and solidified for repairing. it can.

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, since it is not necessary to excavate a relatively large vertical hole in the soil in which the underground buried pipe is buried, a single hole may be formed. This simplifies the work and does not cause a traffic obstacle when the place where the underground pipe is buried is a road, and there is no danger of destroying ground structures such as roads. Furthermore, it is possible to suppress the generation of noise and vibration. 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 a hole 10 in the soil 7, and FIG. 3 is a step of forming a region 29 which is a cavity. A cross-sectional view, FIG. 4 is a cross-sectional view showing a process for investigating a gas leakage state from a repaired portion of the underground buried pipe 8, and FIG. 5 shows an outer peripheral surface of the repaired portion of the underground buried pipe 8 in a region 29. FIG. 6 is a cross-sectional view for explaining the step of examining using the optical fiber 31, FIG. 6 is a cross-sectional view showing a state in which the sealing agent is supplied to the region 29 and a part of the pipe body 13 for repair, and FIG. Sectional drawing which shows the process of making the area | region 36 empty by the self-propelled excavator 34, FIG. 8 is a perspective view of a part of the pipe 37 of other Example of this invention, FIG. It is a sectional view of a technique. 7 …… Soil, 8 …… Underground pipe, 10 …… Hole, 13,37 ……
Tube, 23 ... Suction pump, 26 ... Sealant supply source, 28 ...
… Water supply

─────────────────────────────────────────────────── ─── 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 single hole is formed in the soil in the vicinity of a repaired portion of an underground buried pipe from the ground, and two vertically extending passages are formed in this hole, and fluid is supplied from either one of the passages. A method for repairing a buried underground pipe, which comprises pumping, discharging the soil of a repaired part together with a fluid from the other, and then supplying a sealant from at least one of the passages to cover the repaired part with the sealant.