JPS6178928A - Repairing of outside of tube buried underground - Google Patents

Abstract

PURPOSE:To prevent the occurrence of explosion during repairing operations by a method in which the surrounding ground of the coupler of a tube buried under the ground is excavated by a vacuum excavation method, and sand is recovered while sucking leaked air around the coupler even during the cleaning operation of the coupler by sand blasting. CONSTITUTION:The coupler A of a tube 1 buried under the ground is exposed in a vertical pit 5 excavated by sucking sand with leaked gas, etc., by a vacuum excavating vehicle. The surrounding soil of the coupler A so exposed is cleaned by a sand plaster 16 and removed through a suction hose 6. A sealing cover 2 is hermetically covered on the coupler A, consisting of an injection tube through which a sealant is injected from the ground's surface and an exhaust tube 4 through which air in the cover 2 is discharged to the ground's surface. The sealing operation of the coupler of the tube can thus be made while preventing explosion by the vacuum air ventilation.

Description

[Detailed description of the invention] (Field of application 1 of production 1't'2) The present invention is directed to the existing u, 2
For piping, especially pipe joints, excavate locally to avoid exposing them inside the hole, and from the outside, for the purpose of maintaining airtightness, drill the pipe joints etc. (made of mino fat). Repair using a sealing material (One example concerns a method for repairing the external surface of underground pipes.

[Prior art 1] In general, existing pipes such as gas pipes that are installed underground (under the road) are affected by the load and vibration of a single pipe running on the road, earthquakes, or aging, which may cause the connection of pipe joints to deteriorate. may change, creating gaps and causing gas leaks.

Therefore, recently, a method has been proposed in which the existing pipes are left in place and repaired using a sealing material made of resin or the like from the outside of the pipe body.

This supplementary piece construction method is described in, for example, Japanese Patent Publication No. 53-3099, Japanese Utility Model Publication No. J2-179215" + Publication, etc.:
A sealing cover is placed on the outer circumferential surface of the pipe exposed in a hole opened to the ground by excavation, as shown in the figure above.
A liquid sealing material made of resin or the like is filled into the cover and assimilated c! C,? III fj stand□, fノ') -1
There is -'/h.

like this? To carry out M repair, turn the pipe joint 1■I
Taking the case of construction as an example, construction is carried out according to the following work process.

■ Before starting repair work, detect the occurrence of flue-shaped parts.

A vertical hole is excavated using a pneumatically operated excavation tool at the position of each detected pipe pot, and the pipe joint that was buried in this excavated vertical hole is exposed.

) Sandblast the exposed outer circumferential surface of the pipe joint to remove any dirt and sand that may have adhered to the surface and clean it so that the sealant will fit well.

0) After this cleaning 1. : Apply a urethane-based primer to the outer peripheral surface and moisten it to improve adhesion with the sealant that will be filled later.

(■ Next, wrap the sealing cover so that it covers the top part of the tube 1, making sure it is covered.

■ A liquid sealing material made of a two-component urethane resin that hardens at room temperature is injected into the sealed sealing cover, filling the gaps between the sealing cover and the pipe joint, and solidifying.

(2) After curing, an airtightness test is carried out, and once the airtightness is confirmed, backfilling and compaction are carried out to complete the 421-step process of repairing.

[Technical Problem of the Invention 1] In a certain case like this, it was predicted that the pipe joints that needed repair had already lost their airtightness, and the leaking gas was removed before excavation. In addition, leaked gas may flow into the excavated vertical hole from the excavated and exposed pipe joint, mix with air, and form an explosive atmosphere.

Therefore, if sparks are generated due to the impact between the drilling tool and rock in the formation during the excavation process, or the impact of the blast sand on the laying body during the lead-in process, an explosion formed by the leaked gas may occur. There is a risk of ignition of the hazardous atmosphere gas, causing an accident.

[Object of the Invention] The present invention has been made in order to solve the problems that occur in the conventional construction methods as described above.

During the excavation process, the earth and sand produced by excavation are
1. While removing the soil using vacuum suction, the inside of the excavated pit is ventilated by the suction, and during the cleaning process, vacuum suction is continued and ventilation is performed while collecting the jetted sand.This ventilation prevents an explosion. The purpose of this project is to provide a method for repairing underground pipes that prevents harmful atmospheric gases and allows safe installation and repair of underground pipes.

(Structure 1 of the Invention) For this purpose, the present invention aims to prevent the joints of existing pipes laid underground from being exposed in holes made above ground by cutting, and to apply resin or the like from the outside of the pipe body. This is a method of refilling using a sealing material of 1' is characterized by the fact that when carrying out this process, the air in the hole excavated with 1 suction hose is sucked in, and the sand is collected while providing ventilation. is.

[Example] Hereinafter, a specific example of the present invention will be explained with reference to the drawings.
,:explain.

In the figure, reference numeral 1 indicates an existing underground pipe that was better connected (lost) to water supply type pipe fitting A, such as city gas. Supplementary from;
39- This is a sheet-shaped sealing cover whose outer circumferential surface is pushed aside, and the gap between the tube joint and the pipe fitting is filled with a sealing material and solidified. This sealing cover 2 is made of an airtight flexible woven fabric coated with oil on its inner surface, and is fastened with a zipper or the like to airtightly enclose the pipe joint A, which is the object of the cover. .The symbol @3 is the injection pipe for injecting the sealing material into the sealing cover 2, and the symbol 4 is the gap between the sealing cover 2 and the pipe fitting depending on the amount of filling of the sealing material 1g. It is an air vent bamboo for discharging the accumulated air inside.'r3 Bow 51, Supplementary]: It is a pit excavated for Mi. Code 10 (Y, vacuum product 1jjll car, engine 1111-driven) The vacuum pump 12 is equipped with a hopper section 13, a filter section 1, 1, a compressor 15, a sandblasting device 16, etc., which separates and lifts the earth and sand sucked in by the vacuum pump 12. Reference numeral 6 is a branch hose connected to the vacuum pump 12, reference numeral 7 is an air hose, reference numeral 8 is an excavation tool, and reference numeral 9 is a sandblasting +1j~river nozzle part)A.

Next, the repair work process according to the present invention will be explained.

(Re 110■ Construction 1) In a, the position δ of the pipe joint part Δ, which is the target of the supplementary pg, is detected using the known y-no method.

■ At the position of the detected pipe J1 hand A, use the air-operated excavation tool 8 to excavate the minimum necessary length of the vertical hole 5.
ZW Conjuring) 22 There are 12 people leaking gas in F1, and the sparks generated by the excavation fF 2t could ignite the ejected gas or even cause a local explosion. No danger is expected.

Therefore, the excavated earth and sand are removed by the suction bow 6 connected to the vacuum pump 12, and the gas released from within the soil layer is simultaneously sucked in r: Always maintain adequate ventilation to prevent the formation of a wall-induced atmosphere.

In this way, the pipe joint part A @ to be repaired is exposed inside the excavated shaft 5, but since gas is thought to be leaking from the pipe joint part A, suction ventilation with the suction hose 6 is carried out in the shaft 5.
Continue to perform Nvc even after the formation of the

0) Next, the dirt adhering to the circumferential surface of the ejected flute joint flat part Δ is removed by operating the injection nozzle member 9 connected to the sandblasting narrow mouth 1G, and the surface is cleaned. This removed sand F is discharged by the suction hose 6, and the suction simultaneously ventilates the inside of the pit 5, so even if sparks are generated by sandblasting, there will be no explosion, and it will be safe. I can do the work.

■ Next, apply a urethane primer to the cleaned outer peripheral surface and moisten it.

■ After that, drop the long extended fastener of the sealing cover 2 into the vertical hole 5, and attach it with the hook rod (2).
F is pulled up through the lower surface of the flat part of the hand, and the zipper is tightened to cover the bag.At this time, position the air 1 and friend tube 4 so that it is located directly above, and cover the bag.

When this work is completed, the drive of the vacuum pump 11 is stopped.

■,■ In this process, the same operations as in the conventional process are performed, and the series of operations in the repair process is completed.

By performing such V operations, the (2) members do not need to enter the excavation shaft 5 and perform a series of FLE operations.
Since the work can be carried out always outside the excavated shaft 5, safety is further ensured. In addition, since there is no need to enter the strut into the excavated shaft 5, the area of the excavated shaft 5 can also be reduced to the minimum required 1a.

(Effect of drilling 1) As detailed above, the present invention is useful for cleaning underground gas pipes, etc., during excavation work, repairing by Nando blasting, and cleaning the pipe surface. V
However, because construction work was carried out while constantly evacuating the inside of the pit by vacuum suction, there was a possibility that sparks would be generated by excavation or sandblasting, which could lead to an explosion. Furthermore, since the work can be done from outside the lung pit, the oil gap work can be done extremely safely (q).

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view illustrating a construction method in which a sealing cover is wrapped around the joint of underground construction, and the sealing material is filled and solidified to compensate. Figure S2 is a sectional view for explaining the vacuum suction excavation process and the cleaning process.

Claims (1)

[Claims] This is a construction method in which the joints of existing pipes, etc. laid underground are exposed in a hole opened above ground by excavation, and repaired using a sealant made of resin or the like from the outside of the pipe body. When performing cleaning work by excavating the area to be repaired while suctioning and sandblasting the outer circumferential surface of exposed pipe joints, etc., the suction hose is used to suck out air that could potentially leak gas from the excavated hole. A method for repairing the outer surface of underground pipes, which is characterized by collecting sprayed sand while providing ventilation.