JPH07109890A - Double pipe jacking method - Google Patents

Abstract

PURPOSE:To center and connect inner pipes together in sequence with high accuracy and advance under the ground by adjusting the feed quantity of gas into a gas bag arranged between the outer pipe and inner pipe of a jacking double pipe arranged in a vertical shaft. CONSTITUTION:The second double steel pipe constituted of an outer pipe 51 and an inner pipe 52 having the same structures as those for the first double steel pipe is mounted on a mount, and a gas bag 70 is arranged between the outer pipe 51 and the inner pipe 52. The gas bag 70 is filled with gas to lift the inner pipe 52, and the centering between the inner pipes of the first and second double steel pipes is performed relatively easily by only the shift of the inner pipe 52. The rear end of the inner pipe of the first double steel pipe and the front end of the inner pipe 52 are welded, the outer pipe 51 of the second double steel pipe 50 is slid forward, and the front end of the outer pipe 51 is brought into contact with the rear end of the outer pipe of the first double steel pipe. Driving force is applied to the rear end of the outer pipe 51 of the second double steel pipe 50, and the second double steel pipe 50 is connected to the first double steel pipe for the underground advance. When the gas bag 70 is employed, the concentrated load to the inner pipe 52 is avoided, and the occurrence of strain and scars on the inner pipe 52 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion method for laying a double pipe for propulsion, which has an inner pipe and an outer pipe, in the ground by propelling the double pipe for propulsion into the ground.

[0002]

2. Description of the Related Art For example, when laying high pressure gas underground,
Usually, a groove is excavated from the ground along the route to be laid, a gas pipe is arranged in the groove, the gas pipes arranged in the groove are welded to each other, and the groove is backfilled to form a gas in the ground. The pipe is laid. On the other hand, when laying a gas pipe in the ground across a road or river, it is necessary to create a detour for the road or river in order to open the groove from the ground, so instead of the method of cutting the groove from the ground, In some cases, a propulsion method is adopted in which a vertical shaft is dug and a pipe is propelled into the ground from the horizontal wall of the vertical shaft. When adopting this propulsion method, in order to prevent flaws and the like from occurring in the gas pipe, there is a method of propelling the fume pipe into the ground and pulling in or pushing the gas pipe into the fume pipe propelled into the ground. Adopted.

However, the strength of the fume tube is relatively weak,
Generally, about 100 m is the limit for propelling this relatively weak fume tube into the ground, and it is difficult to propel it over a long distance without relaying it on the shaft, and it is difficult to propel it over a wide river. It is not suitable for long-distance propulsion such as when crossing a river mouth. In addition, in the above-mentioned propulsion method, it is necessary to first propel the fume tube and then pull in or push the gas tube into the fume tube regardless of the propulsion distance.

As a propulsion method that solves these problems,
A propulsion method for propelling a double steel pipe in which an inner pipe is arranged inside an outer pipe into the ground has been proposed (for example, Japanese Patent Application No. 4-18391)
8 and Japanese Patent Application No. 5-044860). In this propulsion method, propulsive force is applied only to the outer tube so that the inner tube is not distorted or damaged. By the way, when laying gas pipes in the ground, for convenience of transportation and handling, for example, a steel pipe with a length of about 6 m is manufactured at the factory and transported to the laying site.
The pipes are welded and buried at the laying site.
In this welding, it is necessary to properly center the pipes to be welded.

FIG. 4 is a view showing a pipe arranged in a cut groove, and FIG. 5 is a sectional view taken along line XX of FIG. A horizontal bar 12 that supports the steel pipe 20 in the width direction of the groove 10 that is cut from the ground.
The steel pipe 20 is suspended inside the groove 10 by the chain 14. In this suspended state, the steel pipe 20 moves considerably freely. Therefore, the lengths of the chains 14 and the suspending position are adjusted so that the steel pipes 20 are centered with each other, and the pipe ends of the centered steel pipes 20 are adjusted. The two are welded together.

The centering can be performed in the same manner even in the method of propelling the fume tube into the ground and then disposing the steel tube in the fume tube. That is, by adjusting the position of the steel pipe suspended in the vertical shaft, the steel pipe and the steel pipe pulled in or pushed into the fume pipe can be centered.

[0007]

However, when adopting a propulsion method for propelling a double steel pipe in which an inner pipe is arranged inside the outer pipe into the ground, how to perform centering of the inner pipes is performed. Becomes a problem. Similar to the case shown in FIGS. 4 and 5,
It may be possible to suspend a double steel pipe in the vertical shaft, but since the double steel pipe is a steel pipe with a double structure, it is very heavy and difficult to suspend, and even if suspended, its position adjustment is difficult. . Also, when suspending, the outer pipe is suspended, but it is the inner pipe that is desired to be centered, and it is difficult to center the inner pipe with sufficient accuracy even if the position of the outer pipe is adjusted. Is.

In view of the above-mentioned circumstances, the present invention provides a method of connecting the inner pipes to each other with sufficient accuracy when the double pipes for propulsion in which the inner pipes are arranged inside the outer pipes are sequentially connected and propelled into the ground. The purpose is to provide a double pipe propulsion method that can be put out.

[0009]

The double pipe propulsion method according to the present invention which achieves the above object, is relatively movable between an outer pipe and an outer pipe arranged inside the outer pipe. In the double pipe propulsion method in which the double pipes for propulsion with the inner pipe are sequentially connected to each other and the double pipe for propulsion is propelled into the ground from the lateral wall of the shaft, (1) Propulsion process of propelling the pipe underground until the rear end of the first propulsion double pipe projects from the horizontal wall of the shaft (2) Inside the shaft, the rear end of the first propulsion double pipe Arranging step of arranging the second propulsion double pipe connected to the (3) gas which is arranged between the outer pipe and the inner pipe of the second propulsion double pipe and expands by feeding gas By adjusting the amount of gas fed into the bag, the inner tube of the first propulsion double pipe after the completion of the propulsion step and the end of the arrangement step described above. Centering step of performing centering with the inner tube of the second propulsion double pipe after (4) after the completion of the centering step, the inner tube of the first propulsion double tube and the second propulsion tube While connecting the inner pipe of the double pipe,
A connecting step of bringing the outer tube of the second propulsion double tube into contact with the outer tube of the first propulsion double tube by moving the outer tube of the second propulsion double tube forward. It is characterized by that.

[0010]

According to the double pipe propulsion method of the present invention, a gas bag is arranged between the outer pipe and the inner pipe of the second propulsion double pipe arranged in the vertical shaft, and the gas to the gas bag is provided. Since the centering is performed by adjusting the feed amount, only the inner tube is adjusted in position, which is lighter than the case where the position of the entire double tube is adjusted, and further, the centering is desired. Since the inner pipe is directly adjusted in position, it is possible to perform highly accurate centering.

Further, since the gas bag is used in the present invention, when centering, a fairly wide area of the inner pipe is evenly loaded to avoid a concentrated load, which causes distortion and flaws in the inner pipe. Is prevented from occurring.

[0012]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a view showing the periphery of a vertical shaft when the double pipe propulsion method of one embodiment of the present invention is applied, and FIG. 2 is a YY sectional view of the double pipe shown in FIG. Further, FIG. 3 is a diagram showing a gas bag and a gas cylinder for feeding gas into the gas bag.

FIG. 1 shows a first double steel pipe 40 already propelled into the ground from the lateral wall 31 of the shaft 30. The double steel pipe 40 is composed of an outer pipe 41 and an inner pipe 42. The rear end portion of the first double steel pipe 40 is in a state of protruding into the vertical shaft 30. After propelling the first double steel pipe 40 to the state shown in the figure, a second double pipe consisting of an outer pipe 51 and an inner pipe 52, which has the same structure as the first double steel pipe 40, is mounted on the pedestal 60 in the vertical shaft 30. The double steel pipe 50 is placed. The height of the gantry 60 is higher than that of the core of the inner pipe 42 of the first double steel pipe 40 (shown by a dashed cross in FIG. 2) when the double steel pipe 50 is placed thereon. The core of the inner pipe 52 of the heavy steel pipe 50 (shown by a solid line cross in FIG. 2) is adjusted to a slightly lower position.

After the double steel pipe 50 is placed on the pedestal 60, the gas bag 70 is arranged between the outer pipe 51 and the inner pipe 52 of the double steel pipe 50. In the gas bag 70,
As shown in FIG. 3, a gas cylinder 72 is connected via a gas hose 74, and a gas cock 76 is provided in the middle of the gas hose 74. This gas cock 76
Is operated to inflate the gas bag 70 to lift the inner pipe 52, whereby the core of the inner pipe 52 is aligned with the core of the inner pipe 42 of the first double steel pipe 40. In addition,
When the cores of the inner pipes 42, 52 are displaced not only in the vertical direction but also in the lateral direction or the diagonal direction, the gas bag can be moved in the diagonal position or the lateral position direction like a gas bag 70 'shown by a broken line in FIG. It is applied and centering is performed.

In this centering method, only the inner tube 52 needs to be moved for centering, so position adjustment is relatively easy, and the inner tube to be centered is directly positioned. High-precision centering is performed for adjustment. Furthermore, by using a gas bag, the inner pipe 5
It is avoided that a concentrated load is applied to 2, and the inner tube 52 is prevented from being distorted or flawed.

After the inner tubes 42, 52 are centered as described above, the rear end 42b of the inner tube 42 and the inner tube 5 are
No. 2 front end 52a is welded and then the second double steel pipe 50
Outer pipe 51 is slid forward, the front end 51a of the outer pipe 51 is brought into contact with the rear end 41b of the outer pipe 41 of the first double steel pipe 40, and the outer pipe 51 of the second double steel pipe 50 is kept as it is. The second double steel pipe 50, the first double steel pipe 50 and the first double steel pipe 40 shown in FIG. 1 are in a state corresponding to the first double steel pipe 40 shown in FIG. The double steel pipe 40 and the double steel pipe connected to the front side of the first double steel pipe 40 are propelled into the ground.

By repeating the above steps, the double steel pipes are sequentially connected and propelled into the ground.

[0018]

As described above, in the propulsion method of the present invention, the gas bag is arranged between the outer pipe and the inner pipe of the second propulsion double pipe arranged in the shaft. Since the centering is performed by operating the bag, the inner tubes can be easily centered with high accuracy.

[Brief description of drawings]

FIG. 1 is a view showing the periphery of a vertical shaft when a double pipe propulsion method according to an embodiment of the present invention is applied.

2 is a cross-sectional view taken along line YY of the double pipe shown in FIG.

FIG. 3 is a diagram showing a gas bag and a gas cylinder for feeding gas into the gas bag.

FIG. 4 is a view showing a tube arranged in an opened groove.

5 is a sectional view taken along line XX of FIG.

[Explanation of symbols]

 30 Vertical shaft 31 Horizontal wall of vertical shaft 40 First double steel pipe 41 Outer pipe 42 Inner pipe 50 Second double steel pipe 51 Outer pipe 52 Inner pipe 60 Stand 70, 70 'Gas bag 72 Gas cylinder 74 Gas hose 76 Gas cock

Claims (1)

[Claims] 1. A double pipe for propulsion, which is provided with an outer pipe and an inner pipe disposed inside the outer pipe and relatively movable between the outer pipe, while sequentially connecting the propelling double pipes to each other. In the double pipe propulsion method of propelling a double pipe for propulsion into the ground from the lateral wall of the shaft, the first double pipe for propulsion is constructed such that the rear end portion of the first double pipe for propulsion is the lateral wall of the vertical shaft. A propulsion step of propelling into the ground to a position protruding from the ground, and an arranging step of disposing a second propulsion double pipe connected to a rear end of the first propulsion double pipe in the shaft. The end of the propulsion step is adjusted by adjusting the amount of gas fed into the gas bag, which is disposed between the outer pipe and the inner pipe of the second propelling double pipe and inflates when the gas is fed. Centering of the inner pipe of the first propulsion double pipe after completion and the inner pipe of the second propulsion double pipe after completion of the disposing step And a second propulsion while connecting the inner pipe of the first propulsion double pipe and the inner pipe of the second propulsion double pipe after the completion of the centering process. By moving the outer tube of the dual pipe for operation forward, the second tube is added to the outer tube of the first double tube for propulsion.
And a connecting step of bringing the outer tube of the propulsion double tube into contact with the double tube.