JPH1019165A - Replacement of existing buried pipes - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a method for replacing existing buried pipes that enables the application of the propulsion method even when the diameter is small, and that allows smooth insertion of new pipes. And SOLUTION: After forming a plurality of cut grooves in an inner peripheral surface of an existing pipe 11, an expanding member of a breaker and a sheath pipe 16 are propelled into the existing pipe 11, and the existing pipe 11 is cut open along the entire length.・ Increase the diameter, and then install the new pipe 1 inside the sheath pipe 16
By inserting No. 2, laying replacement work was performed without digging the ground surface of the ground G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the laying of an existing buried pipe suitable for use in replacing an existing pipe such as a steel pipe or a cast iron pipe buried underground with a new pipe due to aging or the like. Regarding the replacement method.

[0002]

2. Description of the Related Art When a part of an existing pipe made of a steel pipe or a cast iron pipe buried underground as a pipe for water supply or sewerage is, for example, deteriorated and needs to be replaced, the ground of the buried part is grounded. Conventionally, a method of excavating an existing pipe, excavating an existing pipe, reconnecting a new pipe, and refilling the ground again has been employed. However, this excavation method,
After excavating the ground at least in the section of the buried pipe to be laid and replacing it with a new pipe, the ground must be rebuilt again, which requires a large amount of excavated soil and requires a lot of labor and labor, and There are several problems that affect the surrounding environment and, if buried underground on the road site, will greatly affect traffic during the construction period.

Therefore, in recent years, a so-called propulsion method has been proposed and put into practical use as a method of replacing existing buried pipes without cutting the ground, instead of the above-mentioned open cut method. This is because, as shown in FIG. 6A, a shaft 2 (only one side is shown) is provided on both sides of the section where the existing pipe 1 is to be laid.
First, the existing pipe 1a in the shaft 2 is removed. Next, as shown in FIG.
A cutting device 4 such as a plasma cutter is inserted into the inside. While moving the cutting device 4 in the existing pipe 1 along the axial direction, the cutting device 4 forms grooves (not shown) extending in the axial direction at a plurality of locations on the inner peripheral surface of the existing pipe 1. Form. Next, as shown in FIG. 6 (c), the existing pipe 1 is expanded and broken along a groove (not shown) by pushing the tapered block 6 into the existing pipe 1 and propelling it. . As shown in FIG. 7A, a new pipe 7 to be newly used is inserted into the existing pipe 1 expanded by this. Thereafter, a backing material is injected into the outer peripheral side of the new pipe 7, and thereafter, as shown in FIG.
Are connected by a joint pipe 8, and the shaft 2 (see FIG. 7A).
And the road is restored to complete the replacement of the pipe with the new pipe 7. Such a propulsion method has the advantage that only the shaft 2 is provided on both sides of the section of the existing pipe 1 to be replaced, so that the amount of excavated soil on the ground can be reduced and the influence on the surrounding environment of the ground surface can be suppressed. have.

Conventionally, ductile cast iron pipes capable of withstanding a large propulsive force have been used as new pipes laid by the above-mentioned propulsion method, for example, in the case of water supply pipes. , T-shaped ductile pipes for propulsion method (by the Japan Ductile Iron Pipe Association) are used.

[0005] In recent years, in order to prevent damage to the pipe itself or its joint portion due to an earthquake, land subsidence, or the like, a pipe for ground-resistant deformation (so-called seismic pipe) has been used. Such a pipe for soil resistance has a configuration in which the joints between the pipes have flexibility, so that the joints can adapt to changes in the ground without being damaged by an earthquake or land subsidence. ing.

Among such pipes for ground-resistant soil fluctuation, as shown in FIG. 8, for example, a joint portion 9a of a ductile pipe 9 for a U-shaped propulsion method is connected to an earthquake-resistant joint as shown in FIG. US-style propulsion method ductile pipe (by the Japan Ductile Iron Pipe Association) 10.

[0007]

However, the above-described conventional method of replacing existing buried pipes has the following problems. That is, in the propulsion method,
It goes without saying that the smaller the diameter of the new pipe to be propelled, the lower the propulsive force that this new pipe can withstand.
For this reason, even the ductile pipe 10 for the US-type propulsion method that is used for ground resistance and that can be used for the propulsion method actually has only φ800 mm or more. Therefore, at present, it is not possible to adopt the propulsion method for a pipe having a small diameter (less than φ800 mm) and resistant to ground fluctuation. Furthermore, after the existing pipe is broken or expanded, the inner peripheral surface is not necessarily smooth, and the end of the broken piece of the existing pipe projects inward, which damages the new pipe to be inserted. In some cases, insertion of the new pipe itself may not be possible.

The present invention has been made in view of the above points, and enables the application of the propulsion method even when the diameter is small, and furthermore, the existing pipe which can smoothly insert a new pipe. An object of the present invention is to provide a method of replacing a buried pipe.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a method for replacing an existing pipe buried underground with a new pipe without cutting and digging the pipe. A first step of forming a plurality of cut grooves extending along the front end, the tip is smaller than the inner diameter of the existing pipe, the rear end is larger than the outer diameter of the existing pipe, and the tip A diameter-enlarged member that is expanded in a tapered shape from the portion toward the rear end,
By propelling the existing pipe into the existing pipe with its tip end forward, the tubular pipe is inserted into the existing pipe from the rear while expanding the existing pipe and breaking it along its entire length. And a third step of inserting a new pipe having an outer diameter smaller than the inner diameter of the sheath tube into the sheath tube.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a method for replacing an existing buried pipe according to the present invention; FIG.

1 to 5, reference numeral 11 denotes an existing pipe (made of steel pipe or cast iron pipe) which is a water or sewer pipe which is buried in the ground and needs to be replaced due to deterioration or the like, and 12 denotes an existing pipe. This is a new pipe in which pipes are newly provided in place of the pipes 11.

The method of replacing the existing pipe 11 with the new pipe 12 in the present embodiment includes a first step of forming a plurality of cut grooves on the inner peripheral surface of the existing pipe 11, and expanding and deforming the existing pipe 11 in diameter. In the second step, a new pipe 12 is installed inside the existing pipe 11.
And a third process of inserting and piping the main process.

First, prior to performing the first step, FIG.
As shown in (1), shafts G1 and G2 are excavated in the ground G to expose both ends of the existing pipe 11 in a section requiring replacement. Then, both ends of the existing pipe 11 that needs to be replaced
1, when exposed to G2, as shown in FIG. 2A, a cut groove 13 is formed in the inner peripheral surface of the existing pipe 11. For this purpose, a plasma cutter or the like that is movable in the existing pipe 11 is caused to travel while emitting plasma from one end to the other end of the existing pipe 11, so that the plasma cutter extends along the entire inner peripheral surface of the existing pipe 11. A plurality of cut grooves 13 are formed. At this time, if necessary, a circumferential groove (not shown) extending in the radial direction may be formed on the inner circumferential surface of the existing pipe 11.

As described above, a plurality of cut grooves 13 having a required pattern are formed over the entire length of the inner peripheral surface of the existing pipe 11.
After the formation of the peripheral groove (if necessary), as a second step, the existing pipe 11 is expanded and broken as shown in FIG. For this, a breaking machine 14 is used. Breaking machine 14
A diameter increasing member 15 for advancing inside the existing pipe 11 to expand and break the diameter of the existing pipe 11, a tubular sheath pipe 16 provided integrally with a rear end side of the diameter expanding member 15, Diameter member 1
5 and a propulsion device 17 for propelling the sheath pipe 16 into the existing pipe 11.

As shown in FIGS. 1 and 2 (b), the diameter-enlarging member 15 has a substantially frustoconical shape whose diameter gradually increases from the front end to the rear end. Existing pipe 11
Is smaller than the inner diameter, and the outer diameter on the rear end side is larger than the outer diameter of the existing pipe 11. A plurality of breakage incision rollers 18 are radially arranged on the outer peripheral surface of the diameter-enlargement member 15, and are rotatably supported respectively. The breaking and cutting rollers 18 are configured to break and cut the existing pipe 11 by being pressed against the inner peripheral surface of the existing pipe 11.

As shown in FIG. 1, the sheath tube 16 has a cylindrical shape made of steel, reinforced concrete, or the like, and has an outer diameter substantially equal to the outer diameter of the rear end side of the enlarged diameter member 15.
The inner diameter is set to be larger by a predetermined dimension than the outer diameter of the new pipe 12 to be laid.

The propulsion device 17 is composed of a hydraulic jack, a controller, a hydraulic drive source, etc., and drives the hydraulic jack to expand and contract by the hydraulic drive source.
Is propelled into the existing pipe 11.

The existing pipe 11 is cut by the breaking machine 14.
In order to expand the diameter, first, the expanding member 15, the sheath tube 16,
The propulsion device 17 is installed in the shaft G1. Then, the expanding member 15 and the sheath pipe 16 are propelled into the existing pipe 11 by the propulsion device 17. Then, the expanding member 15 advances inside the existing pipe 11, and the existing pipe 11 is cut and incised by the breaking and cutting rollers 18, 18,.... Then, the cut-out existing pipe 11
Is enlarged by the rear end side of the diameter increasing member 15.

Then, as shown in FIG.
A back filling material 19 such as mortar is injected into the outer peripheral surface side of the sheath tube 16 continuously pushed behind (see FIG. 1).

As shown in FIG. 2C, the existing pipe 11 is cut along strips 11 ', 11', 11 ', 11',
After cutting and expanding the diameter in the next step,
The new pipe 12 is inserted into the existing pipe 11 whose diameter has been increased. As shown in FIG. 4, similar to the sheath tube 16, the new tube 1
2 is pushed from behind by the propulsion device 17.
Thereby, the sheath pipe 16 is installed inside the existing pipe 11,
Further, the new pipe 12 is set in the sheath pipe 16.

Thereafter, as shown in FIG. 5, the new pipe 12 is connected to both sides thereof with the joint pipe 20 to complete the replacement of a predetermined section of the existing pipe 11 buried underground.

In the above-described method of replacing the existing pipe 11, the following method is used.
After forming a plurality of cut grooves 13 in the inner peripheral surface of the existing pipe 11, the expanding member 15 of the breaker 14 and the sheath pipe 16 are propelled into the existing pipe 11, and the existing pipe 11 is cut and cut over its entire length. After expanding the diameter, the new pipe 12 is inserted into the sheath pipe 16.
, The construction replacement work is performed without cutting the ground surface of the ground G. By the way, the inner peripheral surface of the sheath pipe 16 is provided with the existing pipe 11 by the diameter increasing member 15.
It is needless to say that the new pipe 12 inserted into the sheath pipe 16 can be inserted with a smaller thrust than the conventional propulsion method, as a matter of course, is smoother than the surface in a state where the pipe is broken and expanded. Therefore, when the conventional method cannot apply the propulsion method due to a small diameter, for example, φ80
Even if there is no ductile pipe for the US type propulsion method at 0 mm or less, it is possible to use a pipe for ground resistance fluctuation of less than φ800 mm using another form of seismic joint as the new pipe 12. It is possible to expand the applicable range. Moreover, the size of the newly installed pipe 12 is not limited to the above-mentioned size.
When inserting the new pipe 12, the broken pieces of the existing pipe 11 do not damage the surface of the new pipe 12 or prevent the new pipe 12 from being installed.
Can be smoothly replaced.

In the above embodiment, the existing pipe 1
The diameter-enlarging member 15 that breaks 1 may have any shape and configuration as long as the existing pipe 11 can be broken and expanded. A propulsion device 17 for propelling the expanding member 15
Is not limited to the above configuration, and another configuration may be applied.

[0024]

As described above, according to the method for replacing an existing buried pipe according to the present invention, a plurality of cut grooves extending along the axial direction are formed on the inner peripheral surface of the existing pipe. In one step, a diameter-expanding member tapered from the front end to the rear end is propelled into the existing pipe, and the existing pipe is expanded and broken along its entire length. It comprises a second step of inserting a new sheath pipe into the existing pipe and a third step of inserting a new pipe inside the sheath pipe. As a result, when performing the replacement work without digging the ground surface, the newly installed pipe is, of course, inserted into the inside of the sheath pipe having a smooth inner peripheral surface, so that the new pipe is propelled with a small thrust. be able to. Therefore, even when the propulsion method cannot be applied due to the small diameter in the past, it is possible to perform the propulsion method using a ground-resistant pipe that uses other types of seismic joints. It is possible to expand the applicable range of the construction method. In addition, when inserting a new pipe, the existing pipe will not be damaged and the installation of the new pipe itself will not be damaged due to broken fragments of the existing pipe. Can be.

[Brief description of the drawings]

FIG. 1 is a process diagram showing a method of replacing an existing buried pipe according to the present invention, and is a side sectional view showing a state in which the existing pipe is broken and expanded.

FIG. 2 is an elevational sectional view showing a process of breaking and expanding the existing pipe.

FIG. 3 is a side sectional view showing a state subsequent to FIG. 1 and showing a state in which a sheath tube is inserted;

FIG. 4 is a side sectional view showing a state following FIG. 3, showing a state in which a new pipe is inserted into the sheath pipe.

FIG. 5 is a side sectional view showing a state following FIG. 4 and showing a state where insertion of a new pipe is completed.

FIG. 6 is a side sectional view showing steps of a conventional method of replacing existing buried pipes.

FIG. 7 is a side sectional view showing a state following FIG. 6;

FIG. 8 is a side sectional view showing an example of a new pipe to be replaced.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Existing pipe 12 New pipe 13 Cut groove 15 Large diameter member 16 Saya pipe

Claims (1)

[Claims] 1. A method of laying an existing pipe buried underground into a new pipe without digging a plurality of pipes extending along an axial direction on an inner peripheral surface of the existing pipe. A first step of forming a notch groove, wherein a front end is smaller than the inner diameter of the existing pipe, and a rear end is larger than the outer diameter of the existing pipe, and is directed from the front end to the rear end. By enlarging the diameter-enlarged member that is expanded in a tapered shape into the existing pipe with its tip end forward, while expanding the existing pipe and breaking it over its entire length,
A second step of inserting a cylindrical sheath pipe into the existing pipe from the rear, and a third step of inserting a new pipe having an outer diameter smaller than the inner diameter of the sheath pipe into the sheath pipe. The method of replacing existing buried pipes, characterized by the following steps.