JPS629790B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is applicable to city gas, natural gas, petroleum,
Concerning repair methods for various underground conduits such as water supply pipes.

[Conventional technology]

Conventionally, in order to repair leakage points such as cracks and corrosion holes that have occurred in underground conduits, the following methods have generally been used: (b) A method is used to fill the leakage point with resin supplied from inside the conduit. However, the method (a) above had drawbacks such as requiring a lot of time and effort to find the leakage point, and also requiring a lot of time and effort to dig up and backfill the soil. Furthermore, with the above method (b), the solidified resin tends to peel off when the external water pressure is high, which poses a problem in terms of reliability.

In addition, in the method described in JP-A No. 49-49412, a slurry made by mixing cement with gasoline or kerosene is used, and when the slurry is press-injected into a pipe and seeps underground from the leakage point, gasoline or kerosene is released. It is based on the principle that cement turns into mortar by replacing underground water with water. but,
Subterranean exchange between gasoline and water or kerosene and water not only requires a considerable amount of time, but also complete exchange, that is, complete mortarization, is not always achieved.

[Problem that the invention seeks to solve]

In view of the above-mentioned circumstances, the present invention has been developed to reliably identify all leakage points in underground conduits without having to accurately confirm the leakage location or excavate a large amount of soil, which requires a great deal of time and effort. Moreover, the purpose is to enable repair in a state where the strength against external water pressure is high, there is little wastage of chemical consumption, and the soil outside the leakage point is consolidated in a very short time.

[Means for solving problems]

Therefore, the present invention is capable of filling an underground conduit under pressure with a caking liquid resin, causing it to flow out of the conduit from a leakage point, and solidifying the resin that has flowed out while entrapping the soil around the leakage point. In the method, the solidifying liquid resin is an isocyanate resin, and the isocyanate resin flowing out from the leakage point is solidified by reaction with underground water. It provides a repair method.

[Effect]

In this method, the liquid isocyanate resin reacts with underground water almost instantaneously and solidifies, so that the leakage point of the pipe is tightly closed from the outside. After this repair work, if necessary, the entire inner surface of the aging conduit can be lined.
Of course, this can be done reliably and with high reliability.

〔Effect of the invention〕

Unlike conventional cement slurry, which has a high viscosity, the press-filled isocyanate-based liquid resin with good fluidity flows out and solidifies even from the smallest leakage point in the pipe, resulting in an extremely perfect sealing effect. It will be done. In this way, the above-mentioned technical problem is reliably achieved.

Furthermore, if a lining treatment is performed after carrying out the method of the present invention, the lining layer will be firmly held on the inner surface of the pipe without fear of peeling off due to the external pressure of groundwater.

〔Example〕

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

As shown in Figure 1A, the gas pipe 1, which is an underground pipe that has a rising pipe section to the ground, is cut after the minimum necessary excavation work is done on both sides of the part to be treated, and then the gas pipe 1 is cut off to the ground for emergency treatment. The connection of the conduit 2 makes it possible to continue gas transport even during repair work, and flexible tubes 4 and 5 equipped with quick couplings 3 are connected to both ends of the cut conduit 1.

Next, as shown in FIG. A pressurized air supply device 9 is connected via a pressure regulator 8, and the inside of the cutting conduit 1 is replaced with an air atmosphere by supplying pressurized air, and at the same time, dust and moisture inside the pipe are removed.

Next, as shown in FIG. 1C, elastic bodies 10, 10 each having two stages of skirt parts 10a, 10b at the front and rear to improve sealing properties are installed inside the case 7, and the A liquid isocyanate resin a that solidifies is injected between the objects 10 and 10 through the injection tool 7a, and a resin recovery tank 11 is connected to the other flexible tube 5, and pressurized air from the supply device 9 is is adjusted to a constant pressure by the regulator 8 and supplied.

By supplying this pressurized air, both the objects 1
The resin a between 0 and 10 is pressurized and filled in the cutting conduit 1 between the objects 10 and 10, and moves within the pipe together with the objects 10 and 10 while maintaining this state. (See Figure 1 D) When this resin a moves inside the pipe under pressure,
If there is a leakage point such as a crack or a corrosion hole in the wall of the pipe 1 along the movement route, the resin a under pressure will flow out from the leakage point while penetrating into the soil outside the pipe, and it will react with ground water. As a result, the soil around the leakage point is consolidated, and by forming a solidified material around the outer surface of the conduit at the leakage point, leak repair with high mechanical strength against external pressure can be performed. (See FIG. 2) Moreover, the repair can be reliably carried out at all leakage points over the entire range of the cut conduit 1 without having to repair any leakage points.

Next, as shown in FIG. 1E, the object 10,
10 and excess resin a are collected, and if necessary, an object 12 is placed inside the case 7, and the non-gelled resin a inside the tube is collected by moving it with pressurized air.

The embodiments of the present invention have been described above, and the lining treatment performed subsequent to the above-mentioned repair work will also be described below.

In other words, as shown in FIG. A lining material collection tank 13 is connected to the flexible pipe 5, and the lining material b is evenly adhered to the inner surface of the conduit 1 by moving the objects 15, 15 by supplying pressurized air from the supply device 9. Further, if necessary, heating fluid is supplied to accelerate curing of the lining material b, thereby performing a coating treatment on the inner surface of the tube.

In this way, by performing coating treatment after repairing the leakage area, underground water will enter between the inner surface of the pipe and the coating membrane, and the water will cause the lining material to deteriorate or the pipe to shrink. It is possible to reliably avoid situations such as leakage, and it is possible to perform coating treatment with high reliability.

Finally, after removing the flexible tubes 4, 5 and the first aid conduit 2, and taking steps to ensure that the cured lining material b and the tube wall are bonded at both ends of the cut conduit 1, as shown in Figure 1 As shown, connecting conduit 1
4, the underground conduit 1 is connected back to its original state to complete the repair work.

If a conduit for transporting liquid such as petroleum or water is to be repaired, drainage treatment may be performed prior to cleaning the inside of the pipe as shown in FIG. 1B.

As the liquid isocyanate resin a, for example, toluene diisocyanate, diphenylmethane diisocyanate, organic isocyanate polyether triol prepolymers, etc. can be used. In addition, for example, by mixing a solvent or diluent such as methyl ethyl ketone, xylene, toluene, ethyl acetate, or cellosolve acetate into resin a in advance and adjusting the viscosity, gelation time, etc., it is possible to reliably remove the leak from the leakage point. It can be adjusted so that resin a flows out in appropriate amounts. In addition, various resins other than isocyanate resins can be used, and these are collectively referred to as caking liquid resin a.

Furthermore, if a resin with primer properties is used as the caking liquid resin a, it is even more convenient because the adhesive strength between the conduit and the lining material b can be greatly increased.

The covering lining material b can be in various states such as cylindrical, powder, liquid, etc., and in order to attach the lining material b to the inner surface of the pipe, For example, by using an adhesive, or by effectively utilizing the thermosetting, room temperature curing, or anaerobic curing properties of the lining material b itself.
Various formats are available.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for repairing an underground conduit according to the present invention, and Fig. 1 A to E show the conduit repair procedure, Fig. The figure is an explanatory diagram showing a leakage point repair state. a... Consolidating liquid resin, b... Lining material.

Claims (1)

[Claims] 1. A method of filling an underground conduit under pressure with caking liquid resin a, causing it to flow out from the leakage point to the outside of the conduit, and solidifying the spilled resin a around the leakage point while entrapping the soil, A method for repairing an underground conduit, characterized in that the caking liquid resin a is an isocyanate resin, and the isocyanate resin flowing out from the leakage point is solidified by reaction with underground water.