JPH0367193B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a method of continuously covering the outer periphery of a pipe such as a sewer pipe with a cylindrical impermeable membrane when laying a pipe such as a sewer pipe in the ground. The present invention relates to a method of coating an underground pipe body with an impermeable membrane in which the pipe body is laid.

(Prior art and its problems) Conventionally, a propulsion method has been adopted as a construction method for laying pipe bodies such as humid pipes underground.

In this construction method, the pipe body is connected to the shield machine, and the rear end of the pipe body is pressed by a propulsion jack installed in the shaft. A conduit is formed by press-fitting, adding a tube body every time a certain length is pushed, and sequentially press-fitting.

However, the conduit formed in this way
Since the pipes are made by joining pipes of a certain size one after another, in the case of ground with a lot of groundwater, when the pipe is put into service, groundwater will infiltrate into the pipe through the joints, and the actual sewage flowing inside the pipe will leak. There is a problem in that the amount of wastewater to be treated at the sewage treatment plant increases significantly as the amount of water flows in excess of the flow rate.

For this reason, a cylindrical impermeable membrane is placed inside the shield machine in a state in which it is contracted in the length direction, and as the shield machine excavates, the impermeable membrane is paid out from the rear end of the shield machine to cover the pipe body. Things started to happen.

However, in this case, the pipe body moved forward due to pressure from the shaft side and came into sliding contact with the inner circumferential surface of the impermeable membrane fed out from the shield machine side, causing damage to the thin impermeable membrane. .

In addition, the pipe is buried while injecting an anti-friction liquid into the space between the pipe and the ground, and after burying, the anti-friction liquid is replaced with hardening backfilling material to prevent ground subsidence. Another known method is to bury the anti-friction fluid in a tube while injecting the curable backfilling material. This results in waste and is uneconomical.

(Objective of the Invention) The present invention was made in view of the above problems, and it eliminates the sliding of the pipe against the impermeable membrane, reduces the propulsion resistance of the pipe, and prevents subsidence of the ground after the pipe is laid. The present invention provides a method of coating an underground pipe with an impermeable membrane, which can reliably prevent the above-mentioned problems, and can also perform lubricant treatment smoothly and economically.

(Structure of the Invention) The method of coating an underground pipe with an impermeable membrane according to the present invention to achieve the above object is a method of covering an underground pipe with an impermeable membrane, in which the pipe following the shield machine is installed in a shaft while excavating the ground with a shield machine. In the propulsion method in which the pipe body is laid on the ground by pressing with a device, a cylindrical impermeable membrane stored in a shield machine is fixed to the shaft wall, and then the pipe body is joined to the rear end of the shield machine and pushed. While covering the pipe with an impermeable membrane and injecting a lubricant between the impermeable membrane and the outer peripheral surface of the pipe from the front and rear ends of the pipe, the pipe is successively joined and propelled as the shield machine excavates. Then, after the series of pipes reach the reaching shaft, a hardening material is injected between the pipes and the impermeable membrane to push out the lubricant, and the extruded lubricant is introduced into a mixer to mix cement and sand. The method is characterized in that a curable material is prepared by this process, and this curable material is injected between the tube and the water-impermeable membrane.

(Description of Embodiments) Embodiments of the present invention will be explained with reference to the drawings.
2 is the ground, 2 is a starting shaft excavated and formed at a suitable location in the ground 1, and 3 is the wall of the shaft, in which a starting shaft opening 4 is opened.

5 is a shield machine, and a long cylindrical impermeable membrane 6 made of a vinyl sheet or the like is installed at the rear of the skin plate.
A housing section 7 is provided in which the membrane is contracted and stored in the length direction, and the rear end of the housing section 7 is opened rearward and formed at the outlet of the impermeable membrane 6. 8 is the excavation part of the shield machine 5. Reference numeral 9 designates a number of tube bodies following the shield machine 5, which are connected in sequence, and the rearmost tube body 9 is pushed by a pushing device 10 consisting of a propulsion jack installed in the shaft 2.

Reference numeral 11 denotes a ring member fixed to the shaft wall 3 in alignment with the mine entrance 4, and the rear end of the impermeable membrane 6 and the annular packing 12 are fixed watertightly. An injection pipe 14 for injecting a lubricant or a curable material into the space 13 between the water-impermeable membrane 6 and the water-impermeable membrane 6 is attached. Reference numeral 15 indicates a valve provided at an appropriate position on the pipe 14.

Reference numeral 16 denotes a lubricant injection pipe attached to the rear end of the shield machine 5 or the front end of the laying pipe body 9 so as to communicate with the space 13 between the pipe body 9 and the impermeable membrane 6, and a valve 17 is provided at an appropriate position. be.

18 is a pipe body 9 from the starting shaft 2 to the reaching shaft 19
After this, a hardening material made of a self-hardening agent is injected into the space 13 from a pump 20 through a pipe 21 using a mixer installed in the starting shaft 2.

Note that the cylindrical impermeable membrane 6 is formed to have a diameter substantially equal to the outer diameter of the shield device 5.

Now, while excavating the ground with the excavation part 8 of the shield machine 5, press the rear end of the pipe body 9 that follows the shield machine 5 in the shaft 2 and propel the pipe body 9 together with the shield machine 5. Therefore, the impermeable membrane 6 is paid out from the impermeable membrane storage part 7 of the shield machine 5 and covers the pipe body 9, but at this time, the rear end of the shield machine 5 or the front end of the pipe body 9 and the well mouth A lubricant 22 such as a bentonite solution is injected from the side through the injection pipes 14 and 16 into the space 13 between the impermeable membrane 6 and the pipe body 9, and the space 13 is filled with the lubricant 22 under pressure to form the impermeable membrane. 6 from sliding contact with the pipe body 9, and the degree of pressurization by the press-fit lubricant is set to a pressure greater than the sum of underground water pressure and earth pressure.
The outer peripheral surface of the ground 1 is pressed against the excavated ground to prevent the ground 1 from collapsing.

The higher the viscosity of the lubricant 22, the more desirable it is.
If the viscosity is high, the lubricant also moves forward as the pipe body 9 moves forward, and the pressure due to the lubricant decreases inside the space 13 on the shaft side, but as described above, the lubricant is also injected from the mine entrance 4 side at the same time. This eliminates the pressure drop.

In this way, while injecting lubricant at a constant pressure into the space between the outer periphery of the tube and the impermeable membrane 6, the shield machine 5 is dug, and the tubes 9 are successively added to the tubes 9.
is covered with a water-impermeable membrane 6, and when the rear end (front end of the pipe body) of the shield machine 5 reaches the reaching shaft 19, the shield machine 5 is kept in a stopped state.

Next, in this state, the lubricant 22 press-fitted into the space 13 is a non-hardening liquid, and if this liquid escapes, the ground may sink or the pipe body 9 may collapse.
Since the lubricant may move up and down, the lubricant is replaced with a curable material.

The hardenable material may be a mortar made by kneading cement and sand, or a material made by adding bentonite to this mortar.In other words, it is liquid at the time of injection and hardens after a certain period of time after injection. That's fine. Incidentally, it is preferable to mix bentonite into the mortar so that the mortar can easily flow inside the pipe or hose during injection.

This curable material is injected by installing a mixer 18 in the shaft 2, driving a pump 20, and pressurizing the material between the impermeable membrane 6 and the pipe body 9 through a pipe 21 connected to the injection pipe 14. At this time, the curable material is not necessarily injected from one location on the shaft side, but may be injected from the inner surface of the tube body 9 through an appropriate hole.

In this way, the curable material 2 is placed between the water-impermeable membrane 6 and the tube body 9.
3 is injected, the lubricant 22 flows out from the pipe 16 on the side of the shield machine 5 and is replaced by the curable material 23.

Note that the curable material may be injected from the shield machine 5 side and the lubricant 22 may be flowed out from the shaft side.

Further, the lubricant extruded by injecting the curable material 23 is put into a mixer, cement and sand are added thereto, and the mixture is stirred and used as a curable material.

After the hardenable material 23 filled in the space 13 hardens, the shielding machine 5 is removed.

(Effects of the Invention) As described above, according to the method for coating an underground pipe body with an impermeable membrane of the present invention, while covering the pipe body to be laid with the impermeable membrane, a lubricant is applied between the pipe body and the impermeable membrane. Since the water is injected between the pipes, the impermeable membrane is prevented from coming into sliding contact with the pipe body and there is no risk of damage, and groundwater is reliably prevented from flowing into the pipe body, and the propulsion resistance of the pipe body is reduced, making it smoother. can be promoted, and furthermore,
After the pipe is laid, a hardening material is injected between the pipe and the impermeable membrane to replace the lubricant, so the hardenable material can prevent ground subsidence. This is because the lubricant is pushed out and the extruded lubricant is introduced into a mixer and mixed with cement and sand to prepare a curable material, and this curable material is injected between the pipe body and the impermeable membrane. By using a lubricant as a part of the curable material, the material can be reused without waste, which is economical, and the injection process of the curable material can be performed smoothly and efficiently, improving workability. .

Further, the lubricant and hardening material are completely prevented from penetrating into the ground by the water-impermeable membrane, thereby eliminating usage loss.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a simplified longitudinal side view showing a state in which the tube is propelled while injecting a lubricant, and FIG. 2 is a simplified longitudinal side view showing a state in which a curable material is injected. be. 1...Ground, 2...Shaft, 5...Shield machine,
6... Cylindrical impermeable membrane, 7... Storage part, 9... Pipe body, 10... Pressing device, 13... Space part, 14,
16...Injection pipe, 22...Lubricant, 23...Curable material.

Claims (1)

[Claims] 1 In a propulsion method in which a shield machine excavates the ground and a pipe body following the shield machine is pressed by a pressing device installed in a shaft to lay the pipe body in the ground, a cylindrical impermeable pipe stored in the shield machine is used. After fixing the membrane to the shaft wall, the tube body is joined to the rear end of the shield machine and pushed forward, thereby covering the tube body with an impermeable membrane and removing the impermeable membrane and pipe from the front and rear ends of the tube body. The pipes are sequentially joined and propelled as the shield machine excavates while injecting a lubricant between the outer circumferential surfaces of the body, and after the series of pipes reach the reaching shaft, a hardening material is inserted between the pipes and the impermeable membrane. A hardening material is prepared by injecting the lubricant and extruding the lubricant, and introducing the extruded lubricant into a mixer to mix cement and sand, and then injecting this hardenable material between the pipe body and the impermeable membrane. A method for coating an underground pipe body with an impermeable membrane, characterized by: