JPS6221992A - Laying replacing method of underground buried pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to renewal of underground pipes.

[Prior Art] Cast iron pipes, asbestos pipes, etc. for water supply and sewage that are buried underground become obsolete and corrode when used for a long period of time, causing water leakage, so they must be replaced with new pipes.

The most common conventional technology is to excavate the road, dig out the old pipes, remove them, and replace them with new pipes and fill them back in. However, with the recent rapid increase in car traffic, This is not desirable as it will cause severe traffic congestion.

A trenchless construction method is the pipe-in-pipe construction method. This method involves inserting a new pipe with a slightly smaller diameter inside the old pipe and joining them together to form a new pipe. According to this construction method, the cross-sectional area of the new pipe is smaller than that of the old pipe, which inevitably causes the problem that the amount of water supplied decreases.

A conventional technique for replacing a new pipe with a larger diameter than the old one without excavating the ground is the ``underground pipe replacement method'' (
Japanese Unexamined Patent Publication No. 55-95731 (Fig. 3) has been proposed. This invention constructs a vertical shaft 7a in the pipeline of the old pipe 3a as shown in FIG.
A part of the old pipe was hydraulically screwed and gas cut from the inner surface of the old pipe.
Destroy it by hammer blow etc. and remove the fragments.

A new pipe 6a with a larger diameter than the old pipe is inserted into the soil using a hydraulic jack installed in the shaft to replace the removed area, and this process is repeated one after another to renew the pipeline. I'll go.

The company claims that this method not only makes it easy to replace the new pipe with a larger diameter than the old pipe, but also allows the pieces of the old pipe to be collected and reused as scrap.

[Problems to be solved by the invention: It is considered a rational construction method to break the old pipe and replace it with the new pipe. However, this method requires workers to enter the old pipe and destroy the inner wall, so it cannot be applied to old pipes with very small diameters. Additionally, when workers enter the facility, they must work under extremely poor working conditions, including cramped spaces, dust, noise, and vibrations.

In order to solve the above-mentioned problems, the present invention aims to provide a non-cutting method for reinstalling underground pipes, which is the most suitable construction method for old pipes with relatively small diameters and does not create a bad working environment. shall be.

[Means for Solving the Problems] 15 Replacement methods for underground pipes according to the present invention include a leading pipe 1 having a plurality of inclined tips 2 on the end surface of the pipe, and a hydraulic jack for press-fitting the leading pipe 1. 5, a new pipe 6 following this support pipe 4, and a pushing machine 8 following this new pipe 6 are combined, and the old underground pipe 3 is broken with the inclined tip 2. The above-mentioned problem was solved by renewing the pipe by repeating the process of press-fitting the new pipe 6 by the length of the broken pipe.

[Function] FIG. 1 and FIG. 2 A- show an example of the function of the present invention.
The explanation will be based on C.

FIG. 1 is a side view of a leading tube 1 having a plurality of inclined tips 2 on its end surface.

FIGS. 2A to 2C are schematic diagrams showing the construction procedure. In FIG. 2, the inclined tip 2 at the tip of the leading pipe 1 is press-fitted from inside the shaft to the position of the old pipe 3.

In FIG. 2B, the hydraulic jack 5 operates to push the leading tube 1 forward from the rear, leaving the support tube 4 in the same position, and pushes the old tube 3 forward.
is unable to withstand the intensive shearing and compressive force exerted by the inclined tip 2 on its rear end face, and breaks from that part. In this state, a gap is created between the leading pipe 1 and the support pipe 4 by the amount that the hydraulic jack 5 is extended.

In FIG. 3C, the pusher 8 is activated to push the new pipe 6 forward, pushing the previously connected support pipe 4 forward by the gap described above, and the leading pipe and support pipe are connected again. Therefore, through this series of steps, the old pipe is first broken, the new pipe is advanced by the length of the broken pipe, and this procedure is repeated to replace the old pipe with the new one.

By the way, the old pipe fragments and spilled soil that will be generated during the work will be removed from the new pipe side.

(Example] An embodiment of the present invention will be described with reference to FIGS. 1A to 1C.

A part of the pipeline is excavated and a push shaft 7 is dug.

The side walls of the shaft are concreted and back concrete 9 is provided. Line up two type 1 steel in the shaft and install rail 10.
Then, on top of this, the leading pipe 1, the support pipe 4, and the new pipe 6 are connected and arranged in a line. An inclined tip 2 is attached to the front surface of the front tube 1, and a blade body made of a material having high hardness and high wear resistance, such as tool steel, is attached to this tip so as to be replaceable.

On the other hand, the rear surface of the leading tube 1 has a step, and the front surface of the support tube 4 and the pressing member of the hydraulic jack 5 fit into and contact this step, and the tip of the suppressing member presses the collar of the support tube 4 due to the step. . A new pipe 6 continues on the rear surface of the support pipe 4, and a pushing machine is set on the flange on the socket side of the new pipe in the pushing shaft Y. The pushing machine most commonly employs a hydraulic jack, and operates the jack by receiving hydraulic pressure from an external hydraulic source into the cylinder through the oil supply pipe 11B. Note that another oil supply pipe 11A is connected from another oil pressure source to pressurize the hydraulic jack 5 of the support pipe 4. The shortfall in the stroke of the hydraulic jack is compensated for by appropriately holding the distance piece 12.

[Effect of the Invention J Since the present invention achieves the above-mentioned effects, firstly, the leading pipe presses down on the old pipe by itself and loads the old pipe intensively at several places with a plurality of inclined tips, so that the old pipe is Start breaking from the part.

In this case, the effect of the present invention can be particularly fully demonstrated because the old pipes to be replaced are manufactured before the war, such as gray cast iron pipes, asbestos pipes, and ceramic pipes, which have extremely low drag pressure compared to current ductile cast iron pipes. , will be broken relatively easily.

Due to its viscous toughness, ductile cast iron pipes are thought to be difficult to break using this construction method, but this material was converted into a membrane after the war and still has a long service life remaining, so it has not been replaced.

In the present invention, only the leading pipe advances to break the old pipe and then advance the new pipe and the support pipe, so the pushing resistance is extremely small, and therefore the capacity of the pushing machine in the shaft can be small.

In addition, there is no danger that the new pipe interposed between the pushing machine and the support pipe will be damaged due to heavy pressure exceeding its compressive strength.

Compared to the prior art, construction work can be carried out using simple equipment and simple work without placing a burden on workers due to the mutually complementary action of the alternate operation of the hydraulic jacks of the support pipe and the pushing machine.

In addition, by making the new pipe larger in diameter than the old pipe, the disadvantages of the pipe-in-pipe construction method are overcome, and the space inside the pipe becomes larger, making it easier and safer to carry out work inside the pipe, such as removing debris.

[Brief explanation of the drawing]

FIG. 1 is a side view of the leading tube, FIG. 2 A-C is a front sectional view showing the operation of the embodiment, and FIG. 3 is a front sectional view showing the prior art.

Claims (1)

[Claims] In a method of changing the installation of an underground pipe by press-fitting a new pipe into the soil using a pushing machine installed in an excavated shaft, A support pipe 4 equipped with a hydraulic jack 5 for press-fitting the old pipe 3, a new pipe 6 following the support pipe 4, and a pushing machine 8 following the new pipe 6 are combined to convert the old pipe 3 buried underground into an inclined tip. A method for replacing underground pipes, which comprises renewing the pipe by repeating the process of press-fitting a new pipe 6 by the length of the broken pipe after breaking in step 2.