JPH0842287A - Existing buried pipe non-excavation replacement method - Google Patents

Abstract

PURPOSE:To prevent the coming out of small broken pieces by making a plurality of longitudinal grooves on the internal circumference of the existing buried pipe and a circumferential groove on the internal circumference near a flange section, guiding a new pipe with a new pipe guide device to drive, and breaking the existing pipe in a long strip shape. CONSTITUTION:A plasma cutting machine is inserted into the existing buried pipe 13, and the plasma cutting machine is moved in the direction of extension inside the existing pipe 13 while generating plasma from a plasma generator to the front end of a torch. At the same time, the torch is revolved to make a plurality of grooves 19 and 20 in the longitudinal or circumferential direction of the existing pipe so that it is easily broken and cut. At that time, the longitudinal grooves 19 are made on a plurality of circumferential positions of the existing buried pipe 13 and, at the same time, the circumferential groove 20 is made on a straight pipe section 18 adjacent to a flange section 17 to connect the grooves 19 and 20 are to each other. After that, the plasma cutting machine and generator are removed, a new pipe is guided with a new pipe guide device 23 and is driven, and a diameter of the existing pipe 13 is enlarged while breaking and cutting the existing pipe, and the new pipe is successively driven and is buried. According to the constitution, the existing pipe 13 is broken into long strip shaped pieces 13a, and the coming out of small broken pieces, damage in the new pipe and the decline of driving force can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new pipe leading device for use in a construction method in which an existing buried pipe such as a water pipe buried in the ground is replaced with a new pipe by non-open cutting.

[0002]

2. Description of the Related Art As a construction method for replacing an existing buried pipe with a new pipe without cutting, for example, as shown in JP-A-55-95733 and JP-A-63-312593, the existing buried pipe is replaced by a new one. A method is known in which a pipe leading device is pushed in to crush an existing buried pipe and a new pipe is propelled and buried.

[0003]

In this construction method, the groove is formed in the existing buried pipe so that it can be easily crushed. However, since there is no particular device for forming the groove,
It is not known what kind of debris will be generated, and when propelling the new pipe and burying it, small debris gets caught in the new pipe or scratches, increasing the propulsive force, friction of the new pipe tip pipe, new pipe It causes problems such as scratches.

Particularly, when the flange portion 2 of the existing buried pipe 1 and the straight pipe portion 3 of the existing buried pipe 1 are fitted and connected as shown in FIG. 1, the strength of the flange portion 2 is high. Therefore, small fragments 4 are easily generated around the flange portion 2.

Therefore, an object of the present invention is to provide an existing buried pipe non-open cutting cloth replacement construction method capable of solving the above-mentioned problems.

[0006]

[Means for Solving the Problems] After making a groove in the existing buried pipe 13, the new pipe leading device 23 is sequentially pushed into the existing buried pipe 13 by using the new pipe leading device 23 as a guide to push the new pipe leading device. In the existing buried pipe non-open cutting cloth replacement method, in which the existing buried pipe 13 is ruptured and expanded at 23 and the new pipe 22 is sequentially pushed to be buried, a plurality of longitudinal grooves 19 are provided on the inner peripheral surface of the existing buried pipe 13. And inserting a circumferential groove 20 near the flange portion 17 on the inner surface of the straight pipe portion 18 fitted with the flange portion 17 of the existing buried pipe 13, and thereafter inserting the new pipe 22 by using the new pipe leading device 23 as a guide. An existing buried pipe non-open cutting cloth replacement construction method in which it is sequentially pushed into the pipe 13.

[0007]

[Operation] Since the existing buried pipe 13 is reliably broken into the strip-shaped pieces 13a by the circumferentially adjacent longitudinal groove 19 and part of the circumferential groove 20, small fragments do not occur.
The new pipe tip conduit 23 will not be worn or scratched on the surface of the new pipe 22, and the propulsive force will not be increased by biting small fragments, and the existing buried pipe 13 can be reliably and easily made into a strip shape. Since it is broken, the driving force required for breaking can be small.

[0008]

[Example] As shown in FIG. 2, a starting shaft 11 and a reaching shaft 12 are excavated at a place separated by a predetermined distance such as both ends of a road 10, and an existing buried pipe 13 is installed in the starting shaft 11 and the reaching shaft 12. To project.

A plasma cutting machine 14 is inserted from the starting shaft 11 into the existing buried pipe 13, and the plasma cutting machine 14 is generated along the extension direction of the existing buried pipe 13 while generating plasma at the tip of the torch 16 from the plasma generator 15. The torch 16 is rotated while being moved, and a plurality of grooves are formed in the existing buried pipe 13 in the longitudinal direction and the circumferential direction to facilitate the fracture incision. At this time, the existing buried pipe 13 may be cut, but it is preferable to form a groove in order to prevent intrusion of groundwater or explosive gas from the outside of the pipe.

As shown in FIG. 3, the existing buried pipe 13 is buried by connecting a straight pipe portion 18 to a flange portion 17 so as to be connected. As shown in FIGS. 3 and 4, the circumference of the existing buried pipe 13 is reduced. Longitudinal grooves 19 are provided at a plurality of positions in the direction, and circumferential grooves 20 are provided in the straight pipe portion 18 adjacent to the flange portion 17 so that the longitudinal grooves 19 are continuous with the circumferential groove 20. Note that FIG.
As shown in, the longitudinal groove 19a of the straight pipe portion 18 fitted to the flange portion 17 of the existing buried pipe 13 reaches the outer peripheral surface and has a slit shape.

The plasma cutting machine 14, the plasma generator 15 and the like are removed and a propulsion device 21 is provided on the starting shaft 11 as shown in FIG.
The existing buried pipe 1 by promoting the new pipe leading device 23 as a guide.
While rupturing and incising 3, the diameter of the incised portion is expanded, and the new pipe 22 is sequentially promoted and buried.

By pushing the new pipe leading device 23 into the existing buried pipe 13, the existing buried pipe 13 is broken and incised.
As shown in FIG. 2, the longitudinal groove 19 and the circumferential groove 20 make it possible to form a substantially arc-shaped elongated piece, that is, the strip-shaped piece 1 near the flange portion 17.
No small pieces are generated by being broken by 3a.

Next, the details of the operation of processing the groove by the plasma cutting machine 14 will be described. The plasma cutting machine 14 is moved to the reaching vertical shaft 12 side, and the torch 16 is inclined with respect to the vertical direction while traveling to the starting vertical shaft 11 side while irradiating plasma, and the longitudinal groove 19 is processed. At this time, the existing buried pipe 13
When traveling on the flange portion 17, the speed is reduced to form the slit-shaped groove 19a. This operation is repeated a plurality of times to machine a plurality of longitudinal grooves 19.

Next, the plasma cutting machine 14 is attached to the flange portion 17
Run to the vicinity of the torch 16 and rotate the torch 16 to rotate in the circumferential groove 20.
To process.

[0015]

Since the existing buried pipe 13 is reliably broken into the strip-shaped pieces 13a by the circumferentially adjacent longitudinal groove 19 and part of the circumferential groove 20, small fragments are not generated. Therefore, the new pipe tip conduit 23 is not worn, the surface of the new pipe 22 is not scratched, the propulsive force is not increased by biting small fragments, and the existing buried pipe 13 is surely
Since it is easily broken into strips, the driving force required for breaking can be small.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a defect in a conventional method.

FIG. 2 is an explanatory view of a groove processing operation showing an embodiment of the present invention.

FIG. 3 is an explanatory perspective view of a groove.

FIG. 4 is a cross-sectional view showing a groove portion of a connecting portion.

FIG. 5 is an explanatory diagram of a new pipe propulsion operation.

FIG. 6 is a perspective view showing a broken state of an existing buried pipe.

[Explanation of symbols]

13 ... Existing buried pipe, 19 ... Longitudinal groove, 20 ... Circumferential groove, 21 ... Propulsion device, 22 ... New pipe, 23 ... New pipe leading device.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yuichi Kikuchi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Kenji Okubo 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. In-house (72) Inventor Takuro Odawara, 1-3 Shibaura, Minato-ku, Tokyo Shimizu Co., Ltd. In-house (72) Inventor Nao Nomura 23, Tsutsumi, Komatsu-shi, Komatsu, Ishikawa Prefecture Awazu Plant, Komatsu Ltd. Within

Claims (1)

[Claims] 1. A new pipe leading device 2 is formed by making a groove in the existing buried pipe 13 and then sequentially pushing the new pipe 22 with the propulsion device 21 into the existing buried pipe 13 using the new pipe leading device 23 as a guide.
In the existing buried pipe non-open cutting cloth replacement construction method in which the existing buried pipe 13 is ruptured and expanded in diameter at 3 and the new pipe 22 is sequentially promoted to be buried, a plurality of longitudinal grooves 19 are provided on the inner peripheral surface of the existing buried pipe 13. And inserting a circumferential groove 20 near the flange portion 17 on the inner surface of the straight pipe portion 18 fitted with the flange portion 17 of the existing buried pipe 13, after which the new pipe 22 is guided by the new pipe leading device 23. An existing buried pipe non-open cutting cloth replacement method, characterized by sequentially pushing into the pipe 13.