JPS601516B2 - Method for covering the external surface of underground objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a method of coating the external surface of underground objects such as gas pipes.

Conventionally, in order to coat the outer surface of a corrosive object that is already buried underground, the general method is to dig up the soil around the object to be covered, perform treatments such as cleaning the outer surface, and then apply a sealant. It was adopted by However, in recent years, there have been many situations in which soil excavation has become difficult due to road structures, traffic conditions, etc., and even if it is possible to excavate soil, it has the disadvantage of requiring large-scale and inefficient work. There is a need for the development of a method that can cover the outer surface without digging up the surrounding soil. In view of these circumstances, the present invention aims to propose an economical and efficient coating method that can meet the above-mentioned demands.

Embodiments of the present invention will be described with reference to illustrative figures.

Insert the electrode rod from the ground surface directly above the underground object 1, bring it into contact with the underground object 1, and attach this electrode rod to the battery or A-D.
In addition to connecting to the e terminal of a DC power supply device 2 such as a converter, a conductor 3 such as metal magnesium is buried in the ground near the underground object 1 and connected to the field terminal of the power supply device 2. When the power supply device 2 is activated, an electroosmotic action is induced between the underground object 1 and the conductor 3, with the underground object 1 acting as a cathode and the conductor 3 acting as an anode. In other words, intestinal ions in the ground or hydration water P, which is a combination of ions and water.
Hydrogen permeates into the ground toward the buried object 1, which is the cathode, and accumulates around the buried object 1. Also, due to the electrolytic action of the groundwater existing around the buried object 1, hydrogen is generated around the buried object 1. Gas will be generated. Therefore, the water and hydrogen gas around these buried objects 1 form an annular void 4 between the outer surface of the buried objects 1 and the surrounding soil. Next, the injection pipe 5 is pushed in from the ground surface directly above the buried object 1, with its tip facing the void 4, and the sealant S is injected under pressure into the injection pipe 5 using a pressure feeder such as a compressor. Or just pour it in.

The injected sealant S permeates throughout the gap 4 around the buried object 1, solidifies, and covers the entire outer surface of the buried object 1. Although the power supply device 2 is turned off while the sealant S is being injected, it may be left in operation or may be operated intermittently if necessary.

Moreover, after the injection of the sealant S is completed, the injection pipe 5 is pulled out and the hole is filled. As the sealant S, a thermosetting polymer, a rubber-like substance, a curing agent, etc. are used.

Alternatively, a gas phase sealing agent that reacts with water or the like or an emulsion emulsion that is destroyed by an alkali may be used. Specific examples include:

Examples of thermosetting polymers include epoxy resins, urethane resins, ester resins, and ethylene-acetate resins.

Rubbery substances include natural rubber, polyptadiene, butadiene-styrene copolymer, polystyrene-butadiene, acrylonitrile copolymer, polyisobutylene,
Examples include polychloroprene, isobutylene, isoprene copolymer, ethylene propylene copolymer, and neoprene.

Examples of Z-bituminous agents include asphalt, bitumen, tannins, rust preventives, and oils. Examples of emulsions include water or oil emulsions or latexes such as the above-mentioned polymer rubber-like substances and roaring agents. There is.

Furthermore, the inside of the gap 4 can be adjusted as desired by adjusting the applied voltage and the applied time. Furthermore, cations or water may be artificially injected into the vicinity of the buried object 1. According to the above method, there is no need to excavate a large amount of soil around the buried object 1 as in the conventional method 2, and the electrode ridge and the injection pipe 5 are simply pushed in and the metal body 3 is simply buried shallowly. Even when soil excavation is difficult due to traffic conditions, it is now possible to quickly and easily cover underground objects.

Furthermore, in order to form a void 4 around the buried object 1 by electroosmosis, although the sealant S is injected under unsupervised conditions, it is necessary to ensure that the sealant S covers the entire outer surface of the buried object 1. In addition to being able to
The existence of the void 4 can prevent as much as possible the inconvenience that the injection sealant S receives a reaction force from the buried object 1 due to the injection pressure and is dissipated into the ground while separating from the buried object 1. It has now become possible to reliably cover the outer surface of the buried object 1 economically with the minimum necessary injection amount.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the method for covering the external surface of underground objects according to the present invention, and FIG. 1 is a schematic principle diagram explaining the electroosmotic action, FIG. 2 A is a schematic front view, and FIG. 3 is a schematic front view. is a schematic side view. 1...Underground object, 4...Void, S.
...Sealing agent. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A method of coating the outer surface of an underground object 1, in which a void 4 is formed around the underground object 1 by electroosmotic action caused by applying a voltage to the underground object 1 as a cathode, and then A method for covering the outer surface of an underground object, characterized by injecting a sealant S into the void 4.