JPS5816401B2 - Method for preventing chemical liquid from entering underground pipes - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a method for preventing problems caused by intrusion of chemical solutions into underground pipes with built-in cables due to grouting work. It is an object of the present invention to provide a method and a device for filling a gap with a bag in which water is press-fitted and expanded, thereby preventing the chemical solution from entering into an underground pipe.

Conventionally, especially in recent years, during civil engineering work, as a pre-process to excavate soft ground or areas with a lot of spring water, soil improvement chemicals such as cement milk are injected into the ground in advance to harden the geology. So-called grouting work has come to be widely used.

However, this chemical solution that has entered the ground may enter the underground pipes with built-in existing cables and solidify inside, causing various problems within the underground pipes and causing serious problems5. Ta.

Therefore, as in Japanese Patent Publication No. 53-4726, a method is proposed in which a tube is drawn into an underground conduit using a wire rope, etc., and air is forced into the tube to tightly fill it with the inner surface of the conduit, thereby preventing the intrusion of chemical solutions from the outside. However, although there is no problem in empty underground pipes, underground pipes with built-in cables have the serious drawback of damaging the cable when pulling in the wire rope. In both old and new systems, it was difficult to pull in the wire because the cable already existed, and even if the tube was about to be pulled in with the wire rope, there was a risk that it would hit the cable and make it difficult for the tube to enter halfway. .

Furthermore, if air is not continuously injected using a fan, etc., the pressure in the tube will decrease due to air leakage, so it is necessary to constantly inject air, resulting in high costs due to large amounts of wear and tear. However, it has some disadvantages when used for underground conduits with built-in cables.

However, in the present invention, water is used instead of air to inflate and propel the tube into the underground pipe under water pressure, thereby creating a gap between the inner surface of the underground pipe and the surface of the cable. Since we succeeded in filling the gap, even in underground conduits with built-in cables, there is no problem of damaging the cables or making it difficult to enter due to them colliding with the cables, and moreover, the air pressure decreases due to leakage like air. There is no need to worry about water leakage, so once you have injected pressure water, there is no need to replenish it.
It can very conveniently prevent the intrusion of chemical liquids, and
When removing this, the tube can be easily turned inside out and removed from the underground pipe by opening the drain port and letting the water flow out, and pulling the pull-back lobe connected to the inner end of the tube. It is very effective.

Now, to explain in detail the attached drawings showing an example of implementation, 1 is the land where grouting work has been carried out, 2 is the underground pipe, 3 is the cable built in the underground pipe, and 4 is the The starting end of the tube is folded outward and fixed to a mounting ring 5 provided on the inner surface of the underground pipe.

Reference numeral 6 denotes a tube that is pushed inside out by water 7 to expand and propel the tube.

No. 8 is made of clay, and the sharp bends at the ends of the tubes are relaxed to prevent damage to the tubes.

Reference numeral 9 denotes the end of the tube to which a pull-back rope 10 is connected.

Reference numeral 11 denotes a water injection device, which has a water injection port 13 formed in the upper lid 12, and a water injection tube 14 flexibly connected thereto.

Reference numeral 15 denotes a water tank, and the end of the tube 6 passes through the water pipe 14, rises inside the water tank 15, connects to the pulling rope 10, and exits to the outside.

16 is a by-product water inlet, which can be opened and closed as needed.

11 is a pressurizing device, and 18 is a drain port.

19 is a cap that receives the advancing end of the tube.

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[Brief explanation of drawings]

The attached drawings show an example of the implementation of the present invention, and FIG. 1 is a cross-sectional view of the initial stage of tube propulsion, and FIG. 2 is a cross-sectional view of the end of the tube propulsion.
FIG. 3 is a cross-sectional view. 1...Land that has undergone grouting work, 2...
...Underground conduit, 3...Cable, 4...
・Starting end of tube, 5...Mounting protrusion, 6...
...Tube, 7...Water, 8...Clay, 9...End of tube, 10...
Pull-back lobe, 11...Water injection device, 12...
...Top lid, 13...Water inlet, 14...
・Water injection tube, 15...Water injection tank, 16.
... By-product water outlet, 17 ... Pressure device, 18
・・・・・・Drain port, 19・・・・・・Lid plug.

Claims (1)

[Claims] 1 Fix the end of the tube with the end folded outward to the end of the underground conduit containing the cable, connect the inner end of the tube to a pull-back rope, and apply pressure water to the folded inside. By injecting chemical solution, the tube is turned inside out and expands to fill the gap between the inner surface of the underground conduit and the outer surface of the cable, and is suppressed at a desired position in the underground conduit to prevent chemical liquid from entering. Features: A method for preventing chemical liquids from entering underground pipes.