JP2647692B2 - Underground pipe laying replacement method and equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method and an apparatus for laying underground pipes, such as renewal of aging sewer pipes.

[Conventional technology]

Conventionally, as a method of replacing existing pipes, an open-cutting method that cuts out old pipes and replaces new pipes has been applied.However, this method has a defect that traffic congestion is likely to occur and problems such as loosening of the ground are likely to occur. .

 For this reason, various construction methods have been devised that do not rely on digging.

The first is a so-called pipe-in-pipe method in which a pipe having a diameter one size smaller than the existing length is inserted.

However, in this method, the diameter of the new pipe is smaller than the diameter of the existing pipe, the flow rate is reduced, and in the case of sewer pipe, the pipe bottom height is increased, which may cause problems in relation to the front and rear pipes There is.

Further, as a method of preventing the occurrence of this problem, a method of crushing such as expansion crushing and compression crushing in which an old pipe is expanded and crushed, and then a new pipe is installed, is disclosed in JP-A-62-112830. These are disclosed in JP-A-62-125197, JP-A-62-146395, JP-A-62-21992 and the like.

Also, an extrusion method and a drawing method in which an existing pipe is extruded with a new pipe or pulled out from the other end are described in JP-A-62-137486, JP-A-62-112894, JP-A-62-35188, It is disclosed in JP-A-62-25697.

Furthermore, there is a construction method of excavating around a buried pipe as described in JP-A-62-194396, and a method of turning the inner surface of a buried pipe as described in JP-A-61-290125. .

[Problems to be solved by the invention]

However, when the above-mentioned crushing method is applied, when steel bars are used in concrete or when the connection collar is made of steel, it cannot be easily crushed. It can be triggered.

In the extrusion method and the traction method described above, the frictional force between the soil and the pipe is extremely large due to long-term burial, and there is a problem with the place where the reaction force is taken and the strength of the pipe. However, noise is generated, which is not preferable.

The problem to be solved in the present invention is to solve the problems of the conventional construction method at the time of replacing underground buried pipes, and to crush buried pipes having a connection collar in addition to reinforced concrete pipes, ceramic pipes, PVC pipes, etc. It is an object of the present invention to eliminate rock fragments and earth and sand, to improve excavation efficiency, and to ensure that the laying can be carried out without causing any damage to the surrounding area.

[Means for solving the problem]

Underground replacement of the underground pipe of the present invention, the underground pipe is excavated from the inner peripheral surface by a cutter bit provided in the front pipe, excavated by the excavation is removed from the inside of the front pipe and removed,
The above problem was solved by propelling and burying a new pipe in the removal section using a propulsion device.

〔Example〕

FIGS. 1 to 3 show the structure of a bit attached to a cutter head applied to the method of the present invention, and FIGS. 4 to 5 show the structure of the cutter head and its usage.

FIG. 1 shows the appearance of the cutter bit 1. As shown in FIG. In the figure, reference numeral 2 denotes a main blade provided on the outer periphery of the truncated conical body 3. The main blade 2 is usually formed integrally with the main body 3 from a high tensile strength alloy steel or the like.

FIG. 2 is a cutaway view of FIG. 1 as viewed from the direction of the line II-II. As shown in the figure, the main blade 2 provided on the outer periphery of the truncated conical main body 3 has a first blade row 21 and a first blade row arranged in a cross shape on the outer circumference of the main body 3. 21 and the second row of blades 22 arranged just 45 degrees apart alternately in the direction of the axis of rotation.
They are arranged in columns. Reference numeral 4 denotes a hole formed in the blade bottom portion between the main blades 2 to transfer the excavated waste of the existing pipe.

The location and shape of the transfer hole 4 are most important in that the leading edge of the leading edge plays a primary role in the primary crushing of aged pipes and rocks, that is, the leading role, and the last blade in the last row plays the role of opening the thruster track. Except for the front row and the last row, one is preferably provided between each blade 2 in each blade row 21 and 22.

FIG. 3 is a view showing a vertical cross-sectional structure of the cutter bit 1. Referring to FIG. 3, an inner cavity 7 communicating with a pressure fluid supply hole 5 provided at a front end and an earth discharging hole 6 provided at a rear end is formed therein. It communicates with the lumen 7.

FIG. 4 is a sectional view showing a cutter head 10 in which the cutter bit 1 of the present invention is mounted on the leading conduit A, and FIG. 5 is a view of the cutter head 10 as viewed from the front.

Referring to these figures, four cutter bits 1 are usually rotatably mounted around a rear axis C of a guide casing B at the end of a leading conduit A via bearings D.
Then, the passage E of the compressed fluid in the leading conduit A, usually compressed air, communicates with the pressure fluid supply hole 5 of the cutter bit 1 via the rotary seal ring F, and the earth discharging hole 6 at the rear end is connected to the leading conduit A. It is open to the discharge port G. Then, as shown in FIG. 5, the maximum mounting radius R of the cutter bit 1 in the cutter head 10 is configured to correspond to the radius of the existing pipe a.

As a result, the cutter head 10 is rotated by the rotation of the driving device (not shown) provided inside the leading conduit A, and the cutter bit 1 is rotated accordingly.
While the rock drilling blade 2 crushes the underground pipe a, the leading pipe A penetrates by the thrust of the thruster. The crushed pipe pieces and earth and sand are transferred from the transfer hole 4 of the cutter bit 1 to the cutter bit 1.
At the same time, the pressurized fluid is press-fitted from the pressurized fluid supply hole 5 at the tip of the cutter bit 1, so that the pipe pieces and the earth and sand are transferred to the inside of the front conduit A. As a result, the amount of crushed fragments and sediment accumulated in the front conduit A is reduced, so that the penetration of the front conduit A and the frictional resistance are reduced, the propulsion speed is increased, and the propulsion effect is improved.

6 to 8 are views showing an embodiment of the method of the present invention in the order of steps.

FIG. 6 shows an excavated state of the existing pipe a by the cutter head 10 of the present invention. In the figure, a plurality of existing pipes a are laid between a manhole b on the starting side and a manhole c on the arrival side. “d” indicates a starting casing built near the starting manhole c.

First, when replacing the existing pipe a, a small-diameter thruster e is installed in the starting casing d, and the cutter head 10 shown in FIGS. Promoted by As the small-diameter thruster e, it is preferable to use a thruster disclosed by the present applicant in Japanese Patent Application Laid-Open No. Sho 59-198213.

Then, while propelling the forward conduit A having the cutter head 10 attached to the tip thereof into the existing pipe a by the propulsion device e, the existing pipe a is excavated, and the excavated chips of the existing pipe a are discharged from the rear, and the temporary pipe A is discharged. f is connected to the leading conduit A.

FIG. 7 shows the temporary pipe f connected to the starting casing d and the reaching manhole c by the cutter head 10 shown in FIG. Shows the state replaced by.

FIG. 8 shows a state in which the new main pipe g is being propelled by the propulsion unit e and is being replaced with the temporary main pipe f.

In this way, the existing pipe a is excavated and removed from the inside, a temporary pipe is installed in the removed part, and the temporary pipe is pushed out by the propulsion device by the new pipe into the arrival side manhole, and is continuously connected to the trace. A new pipe will be installed.

〔The invention's effect〕

 According to the present invention, the following effects can be obtained.

(1) Since the existing pipe is scraped from the inside and the shavings are discharged from the casing of the propulsion device to the outside, replacement and replacement are possible.

(2) Since a large reaction force is not required for replacement, a special propulsion machine is not required, and a conventional small-diameter propulsion machine can be used.

(3) Since the cutter head itself has a soil discharging ability, the excavation propulsion effect is greatly improved.

(4) Less noise due to vibration and the like.

[Brief description of the drawings]

The accompanying drawings show an embodiment of the present invention. 1 to 5 show the cutter head of the present invention, and FIG.
FIG. 8 to FIG. 8 are views showing a method of replacing a buried pipe by a cutter head. 1: cutter bit, 2: main blade 3: bit body, 4: earth and sand transfer hole 5: pressure fluid supply hole, 6: earth removal hole 7: lumen 10: cutter head 21: first blade row, 22: Second blade row

Claims (2)

(57) [Claims] 1. An underground pipe is excavated from the inner peripheral surface by a cutter bit provided in a front pipe, and excavated debris from the excavation is removed from the inside of the front pipe and removed, and a new propulsion device is used in the removal section by a propulsion device. A method for replacing underground buried pipes, wherein the pipes are buried under propulsion. 2. A pressurized fluid supply hole provided at a tip end of a cutter bit, wherein a main blade row is arranged in a direction of a rotary main shaft, a blade bottom earth and sand transport hole of the main blade row is formed, and a bore is provided inside a cutter bit. And a discharge hole provided at a rear end of the underground pipe, and the discharge hole and the transfer hole communicate with the lumen.