JPS6319483A - Method of drawing replacing construction of underground buried pipe - Google Patents

Abstract

(57) [Abstract] 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 a technology for replacing pipes buried underground, such as water and sewage pipes, and more specifically, to remove existing pipes and lay new pipes at the same time. Concerning methods for pulling out and replacing underground pipes.

Conventional technology Regarding underground pipes, when removing an existing pipe and laying a new pipe to stop aging or change the diameter, the conventional construction method is to excavate the buried location such as a road and remove the existing pipe. There are two known methods: 1. Pulling out the existing pipe and replacing it with the new pipe at the same time.

Among these methods, method (2) is to press the end of the existing pipe (4) in the shaft (1) with a hydraulic jack (11) and pull out the existing pipe, as shown in Figures 6 and 7. The method used is to pull out the existing pipe (4) in the vertical shaft (2) using a winch (12) via a pulling jig (13) attached to the end of the pipe (Figure 6). .

Problems to be Solved by the Invention The method of excavating roads, etc., removing existing pipes, and laying them requires a lot of effort and time to excavate, backfill, and restore road pavement, and the construction costs are high. Additionally, the road has to be closed or narrowed during the construction period, which has the disadvantage of interfering with traffic. On the other hand, in the method of pulling out existing pipes and replacing them with new pipes using hydraulic jacks, winches, etc. installed in the shaft, the adhesion force between the existing pipes and the surrounding ground is greater than that of the normal propulsion method due to the consolidation effect from the ground. As shown in Figures 6 and 7, the stress σC2 generated in the existing pipe (4) is much larger.
σ shows a distribution where it is maximum at the loading point and minimum at the other end. Therefore, the method (2) of applying pushing force and pulling force to the end of the existing pipe to remove it requires a very large force, and also because the existing pipe has deteriorated in strength, the existing pipe must be replaced. There is a limit to the length, and the target existing pipes are limited to short ones, and in some cases, problems such as existing pipes breaking underground, buckling, or breaking may occur, making construction impossible. there were. This invention was made in order to solve the problem of the above-mentioned method (2), in which the existing pipe is pulled out and replaced with a new pipe, which does not require excavation or backfilling of the passage.

Means for Solving the Problems In order to solve the conventional problem (2) above, this invention proposes a method for pulling out and replacing existing pipes by loading them inside the pipes. A plurality of pulling and loading jigs connected by cables are fixed inside the existing pipe, and a new replacement pipe is connected to the rear end of the existing pipe, and the pulling and unloading jigs are pulled from the pipe tip side. This is a method for pulling out and replacing underground pipes, which is characterized by pulling out existing pipes and replacing them with new pipes at the same time.

That is, the present invention is a method of using a plurality of in-pipe loading jigs, providing a plurality of loading points within an existing pipe, pulling out the existing pipe, and replacing the newly installed pipe at the same time.

In this invention, the reason why a method of providing a plurality of loading points in the existing pipe and pulling it out is adopted is as follows.

In the conventional method of loading at the pipe end, as mentioned above, the stress σ generated in the existing pipe is maximized at the loading point, that is, at the pipe end, and minimized at the other end, so that the replacement length can be determined. This is because the stress generated in the existing pipe can be reduced by providing a plurality of loading points in the existing pipe and pulling it out, whereas the existing pipe cannot be extended and causes problems such as breakage.

That is, by installing a plurality of loading jigs in the existing pipe at appropriate intervals depending on the length of the existing pipe, there are a plurality of loading points and the stress generated in the existing pipe is dispersed.

Therefore, the maximum stress that occurs when the existing pipe is pulled out is much smaller than in the conventional method. In addition, this effect eliminates problems such as breakage, buckling, and breakage of existing pipes, and even if the existing pipe breaks during extraction and continuity is lost, the loading point in the pipe can be installed at any position. Therefore, it is possible to continue extraction.

Disclosure of the Invention by Drawings Fig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the working procedure in the above, and Fig. 3 is a stress distribution diagram when there are two loading points in the pipe. , FIG. 4 is a stress distribution diagram when a large number of loading points are provided in the pipe.

That is, as shown in FIG.
2) For the existing pipe (4) buried in the ground (3) between them, run a cable (6) such as a wire into the existing pipe (4) from the vertical shaft (2) on the pipe extraction side. Insert the combined pulling and loading jig (7) (two shown here), press and fix the jig to the inner surface of the pipe, and insert one end of the cable (6) into the shaft (2). A hydraulic jack with a chuck that holds the
8) is installed, and the existing pipe is pulled out and the new pipe is replaced at the same time.

Although drawings are omitted, the pulling/loading jig used in this invention may have a structure in which, for example, a plurality of arc-shaped fixing plates are attached on the circumference so that the diameter can be expanded using an air or hydraulic cylinder. can be used. In the case of a pull-out loading jig with such a structure, the arc-shaped fixing plate is inserted into the pipe with its diameter reduced, and the cylinder is actuated at a predetermined position to expand the diameter of the arc-shaped fixing plate and attach it to the inner surface of the existing pipe. It can be loaded by crimping and fixing.

Next, the working procedure of this invention will be explained based on FIG.

First, the shafts (1) and (2) are formed by excavating at predetermined intervals, and a part of the existing pipe (4) is removed by gas cutting, etc., and the ends of both pipes are connected to the shafts (1) and (21). Expose (Figure a).

Next, from the vertical shaft (2) on the pipe extraction side into the existing pipe (4) buried in the ground (3), two pull-out loads are connected with a cable (6) at a predetermined distance. Insert the jig (7) and place it in the predetermined position (Figure b). Next, a jig (7) for drawing and loading inside the pipe is crimped and fixed to the inner surface of the existing pipe (4), and a hydraulic jack (8) with a chuck is installed in the shaft (2) on the pipe drawing side. Hydraulic jack (8)
Attach the rope (6) of the pull-out loading jig (7) to the
). After that, the existing pipe (4) is installed in the shaft (1) on the pipe lead-in side.
) at the rear end of ′! The hydraulic jack (8) is operated while welding the Ir installed pipe (5), and the operation is repeated in order to pull out the existing pipe (4) and replace it with the new installed pipe (5) (Figure d).

Here, the stress distribution generated in the existing pipe (4) when two drawing loading points are provided in the pipe will be explained based on FIG. 3. The stress distribution in this case is at the loading point A.

The maximum stress is reached at B, but since there are two loading points, the stress is shared between the pipes themselves on both sides of the loading points, and the maximum stress is smaller than in the conventional construction method. The maximum stress in this case is calculated using the following formula.

0 = (K theft ρ As shown in Fig. 3, by connecting an appropriate number of pulling and loading jigs (7) with cables at predetermined intervals according to the length of the existing pipe (4) and pulling out the existing pipe, the existing pipe (4) can be removed. ) will be shared among many people as shown in Figure 4.
Even long existing pipes can be easily pulled out without causing problems such as breakage.

In addition, in the case of a long existing pipe, it is also possible to use both the ignition force at the front end of the pipe and the pressing force at the rear end.

Figure 5 shows an example of the case where only the existing pipe is removed. In this case, the cavity after the removal of the existing pipe (4) is filled with earth and sand (+01) from the sand pump (9) installed outside to create a rough surface. Prevent the subsidence of the ground by dosing chemicals or the like.

As described in detail of the invention, the method for pulling out and replacing underground pipes according to the present invention involves setting a plurality of pulling and loading jigs inside existing pipes, and simultaneously pulling out the existing pipes through the jigs and simultaneously constructing new pipes. Since this method uses a method of laying pipes, it is possible to replace existing pipes with new pipes with high accuracy without any excavation work, and by reducing the stress generated in the existing pipes, the length of the existing pipes that can be replaced can be increased. It is also very effective in resolving problems such as breakage, buckling, and breakage of existing pipes, and since the jig for rough pulling and loading can be installed at any position within the pipe, in the event that existing pipes Even if the pipe breaks and continuity is lost, it is possible to continue pulling out the existing pipe, and there is no problem with the method of pulling out and replacing buried pipes.

Therefore, according to the present invention, work efficiency can be greatly improved, construction costs can be reduced, etc., and this invention has a great effect on changing the usage of underground pipes.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the work procedure in the above, Fig. 3 is a stress distribution diagram when there are two loading points in the pipe, and Fig. 4 is a diagram showing the stress distribution when there are two loading points in the pipe. Stress distribution diagram when a large number of loading points are provided in the pipe, Figure 5 is an explanatory diagram showing the case where only the existing pipe is removed and no VFT pipe is laid, Figures 6 and 7 are schematic diagrams showing the conventional construction method. It is. 1.2... Vertical shaft, 3... Earth, 4... Existing pipe, 5
...New pipe, 6. Cable, 7. Pulling and loading jig, 8. Hydraulic jack, 9. Sand pump. Applicant: Sumitomo Metal Industries, Ltd. Sumikin Lil Pipe Construction Co., Ltd. Figure 3 Figure 4 Figure 6 Figure 7

Claims (1)

[Claims] In a method of pulling out an existing pipe buried between shafts and replacing it with a new pipe, a plurality of pulling and loading jigs connected by cables are fixed in the existing pipe, and a new pipe is installed to replace the rear end of the existing pipe. A method for pulling out and replacing underground pipes, characterized in that by connecting the pipes and pulling the pulling and loading jig from the pipe tip side, the existing pipes are pulled out and the new pipes are replaced at the same time.