JPH033108B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for replacing old pipes buried underground, such as water pipes and gas pipes, with new pipes, and in particular, a method for replacing old pipes with new pipes without digging up the ground surface. It concerns how to replace the .

[Conventional technology] When old pipes, especially cast iron pipes, become obsolete after being buried and become difficult to perform their functions, or when demand increases and capacity is insufficient to replace them with new pipes, it is necessary to completely excavate above ground. Digging out old pipes is expensive and labor-intensive, and it also obstructs surface traffic, so it is desirable to replace the old and new main pipes without digging up the ground.

This is the case with the so-called pipe-in-pipe method, in which a new pipe is inserted into an old pipe underground, but the inner diameter of the new pipe is naturally smaller than the inner diameter of the old pipe, resulting in a reduction in the transport capacity of gas and water.

The prior art that forms the basis of the present invention is an invention that solves this problem, ``Method and Apparatus for Replacing an Existing Main Pipe with a New Main Pipe'' (Japanese Patent Publication No. 60-27873, No. 5
7).

FIG. 8 is taken from a catalog explaining the state of the invention when it is implemented on a commercial basis.

This conventional technology involves attaching a new main pipe or a liner to protect this main pipe to the rear end of the excavator, which has a body with a larger outer diameter than the old pipe, and both move forward together, allowing the tip of the excavator to enter the old pipe. This is a method and apparatus for replacing the old pipe with a new pipe or a protective liner for the new pipe by crushing the old pipe and expanding the gap.

Since FIGS. 5 to 7 show examples of the prior art, some specific details will be mentioned here.

In FIG. 5, the excavator 8a consists of a front part for penetrating into the inner wall of the old pipe 9a and breaking this wall, and a rear part for pulling the protective liner. The front part has a head 16 including a cutting edge 15 as a cutting surface, and its front end is cut forward by a winch (not shown) via a cable 17 inserted through the tube row of the old tube 9a. be drawn to. Also shown in FIG. 6 are vanes 18 attached to the circumference of the body for cutting, at least one of which can be pivoted radially outward from the excavator in order to effectively fracture the wall of the old pipe. . The fluid (hydraulic pressure) pumped through the hydraulic hose 13a that has hidden inside the old pipe and extended from the front pushes up a piston installed in the head of the excavator, and this piston pushes up one end of the blade 18. This increases the inclination angle and causes an effect of pushing the old tube 9a outward from the inner wall in the radial direction. A preferable example is one in which the hydraulic hose 13a is connected to the rear end of the excavator from the rear.

A protective liner 1a to be connected later with this excavator 8a
As mentioned above, the front winch is moved forward by the cable attached to the front end of the excavator. 20, and the piston in the air hammer is preferably slid back and forth by air supplied from an air hose 12a attached to the rear end, and is moved forward impulsively.

Therefore, an air hose for operating an air hammer inside the machine is connected to the rear end of the excavator from the rear. As mentioned above, it is also preferable to connect the hydraulic hose 13a to the rear end, which provides hydraulic pressure for rotating the blades.

[Problems to be Solved by the Invention] The present invention is based on the above-mentioned prior art and has developed related technologies so that it can be implemented more effectively.

The present application is an improvement of the technology particularly in the case of using a protective liner, and as shown in FIG. The new pipe is a continuous long pipe with a small diameter and great flexibility. At this time, it is sufficient to insert the air hose or hydraulic hose connected to the rear end of the excavator into the new pipe in advance, and to move forward in a bendable manner as the new pipe moves forward. However, such new pipes generally have poor mechanical strength (external pressure resistance, wear resistance)
Because of this, if a new pipe (plastic pipe) is attached directly to the rear end of the excavator and both the old and new pipes are replaced, the new pipe will be damaged by wear and scratches due to the resistance of the old pipe fragments and the surrounding ground. Water that has formed on the surface. Therefore, it is recommended to first replace the old pipe with a tubular protective liner made of a material with higher wear resistance than the new pipe, and then apply the so-called pipe-in-pipe construction method, in which the new pipe is inserted inside this wear-resistant liner. There are many.

Although the protective liner has greater rigidity and strength than the new pipe, it loses flexibility, so the embodiment shown in FIG. 8 requires a long starting hole 7a. Moreover, the larger the diameter of the tube, the more remarkable this tendency becomes.

Requiring a long starting shaft to replace the old pipe with a long, highly rigid protective liner results in work loss and
This is not desirable in terms of traffic obstruction. Therefore, it would be reasonable to keep the protective liner short and add it from the rear as the replacement progresses, but in this case, it would be reasonable to keep the protective liner short and add it from the rear as the replacement progresses. The protective liner must be smoothly inserted into the pipe, which makes the work extremely complicated and requires a special switching device.

In order to solve the above-mentioned problems, the present application proposes a method of easily inserting tubes such as hoses into a protective liner cut to a desired length and connecting the protective liner to form a new tube row. For the purpose of providing.

[Means for Solving the Problems] In the method of replacing an old pipe with a new pipe according to the present invention, a tubular protective liner is cut to a desired length, and a slit parallel to the axial direction is passed through the protective liner. Since annular grooves are provided at both ends of the liner, first insert the air hose, hydraulic hose, etc. into the protective liner pipe through the slits, and then
Enveloping both end faces of the preceding and following protective liners, and attaching a split joining ring having an annular protrusion at the end that fits into each groove, the ring is tightly attached to each protective liner. Accordingly, the above-mentioned problem was solved by forming a tube row of the protective liner and inserting a new tube into the tube row.

[Operations and Embodiments] FIG. 1 is a front sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view (side view) taken along line AA in FIG.

The protective liner 1 is cut to a desired length and has a slit 2 extending parallel to its axis extending therethrough. This slit may be opened with a certain width for ease of implementation. At both ends of the protective liner, annular grooves 3A (on the forward end side in the traveling direction) and 3B (on the rear end side) are provided, respectively. As shown in FIG. 1, the joining ring 4 is a short tube split into one piece, and has annular convex grooves 5A and 5B at both ends that can be fitted into the concave grooves 3A and 3B of the previous half. .

A common joining ring is fitted into the rear tips of the two leading and succeeding protective liners to enclose their outer peripheries, and for this connection, they are fastened using a set screw 6. FIG. 3 shows only this part enlarged. The protective liner 4 is split into one piece, and it is desirable for the strength to be secured if the opening part thereof forms an angle of 180° with the slit 2 of the protective liner 1 as shown in FIG.

Figure 4 shows an example of replacing an old pipe with a new pipe using this protective liner.The length of the protective liner is set appropriately, and the starting resistor 7 is set to a length that can correspond to this length. Excavate in the construction pipeline. The well-known excavator 8 is placed in the starting shaft, positioned at the rear end of the old pipe 9 exposed to the starting shaft, and the operation is started. The excavator 8 advances while crushing and expanding the old pipe 9, and when it reaches a predetermined position, the first protective liner 1A is connected to the rear of the excavator. At this time, the rear end of the excavator is usually connected with an air hose 12 and a hydraulic hose 13 that are connected to the compressor 10 and hydraulic unit 11 installed on the ground, but these hoses are connected parallel to the axis of the protective liner. Insert it through the slit. When the first protective liner 1A enters the ground and replaces the old pipe, the joint ring 4 is fitted as shown at the right end in Figure 1 to connect the second protective liner 1B. The old pipes will be replaced with a row of pipes. After the new protective liner has completely replaced the old pipe (or one unit construction area),
A new tube is inserted into the tube row of this protective liner. You can insert a long flexible new pipe at once, or if the pipe is large in diameter and not flexible, cut it to a length that matches the length of the excavation shaft and insert it one by one. You can go there. It goes without saying that the new pipes do not have slits, so they can be used to supply city gas and water.

[Effects of the Invention] By presenting the above method of the present invention, the following effects are produced.

First, by cutting the protective liner to a relatively short length, there is no need for a large-scale tunnel, which reduces labor costs and reduces traffic obstacles. The connection of one protective liner to the next can be easily made in the borehole by using a simple connecting ring. Conventionally, when using this construction method, it was extremely troublesome to insert the air hose or hydraulic hose into the new pipe (in this case, inside the protective liner) to be constructed, and a switching device was prepared just for this purpose. have to,
The work procedure used to be complicated, but the method of the present application has made it extremely simple.

Since the protective liner that is the subject of construction work is also cut to the desired length, installation work inside the mine is easy and labor-saving, and it also has the advantage of requiring less space for transportation and storage. Can be mentioned.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of the embodiment of the present application, Fig. 2 is a side sectional view taken along the line A-A in Fig. 1, Fig. 3 is a partial view showing details of screw fastening, and Fig. 4 is a diagram showing this construction method. 5 to 7 are a front sectional view showing a conventional excavator, and FIG. 8 is a front sectional view showing a conventional construction method. 1... Protective liner, 2... Slit, 3... Concave groove (3A, 3B), 4... Joining ring, 5... Protrusion, 9... Old pipe.

Claims (1)

[Claims] 1. Attach a tubular protective liner to the rear end of an excavator that has a body with a larger outer diameter than the existing main pipe installed underground (hereinafter referred to as the "old pipe"), and pull the front part of the excavator from the front. Pressure air sent from behind through an air hose inserted into the protective liner pipe activates the air hammer inside the excavator, causing the excavator and protective liner to move forward together, causing the tip of the excavator to enter the old pipe and remove it. In the method of replacing the old pipe with a new pipe by expanding the gap while crushing, replacing the old pipe with a protective liner, and inserting a new main pipe (hereinafter referred to as "new pipe") into the protective liner, The tubular protective liner is cut to a desired length and has a slit parallel to its axis passing through it, and an annular groove is provided at each end of the protective liner, so the air hose etc. is first passed through the slit and protected. After fitting into the liner pipe,
Covering both end faces of the preceding protective liner and the following protective liner and attaching them tightly to each protective liner by capping them with a split joining ring having annular protrusions on both ends that fit into the respective grooves. A method for replacing old pipes with new pipes, characterized by forming a pipe row of protective liners.