JPH0379885A - Duct replacing method - Google Patents

Abstract

PURPOSE:To perform the replacement of a duct easily at a low cast by fixing the tip of a lead wire, inserted into an existing duct from the start shaft side, on the arrival shaft side, disposing a new duct larger in the duct diameter than an existing duct at the periphery of the existing duct on the start shaft side, pulling the lead wire from the start shaft side, and by this reaction, pushing the new duct forward underground through a contact member. CONSTITUTION:A lead wire 5 such as a piano wire is inserted from the start shaft 1 side to the arrival shaft 2 side in an existing duct 3, and its tip is fixed at the lid member 6 on the arrival shaft 2 side. A new duct 4 to be newly laid is then disposed on the start shaft 1 side, concentrically with the existing duct 3, and the end part of the new duct 4 is closed by a contact member 8. The duct diameter of the new duct 4 is to be larger than that of the existing duct 3. A pressing member 9 is further disposed at the contact member 8, and when the lead wire 5 is pulled in the direction of an arrow A, by this reaction, the new duct 4 is pressed in the direction of an arrow B by the contact member 8 through the pressing member 9, thus moving the new duct 4 forward. The new duct can be thus laid without drilling underground open.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a pipe replacement method, in particular, a method for replacing an existing pipe with a new pipe without excavating the underground portion of the existing pipe. Regarding the pipeline replacement method.

(Conventional technology) When it becomes necessary to replace an existing pipeline with a new one due to unusability or lack of capacity, the conventional pipeline replacement method
Most of the construction methods involve excavation of the entire length of the underground part of the existing buried pipeline, and the propulsion method, which does not involve excavating the underground part, has hardly been used.

(Problems to be Solved by the Invention) In the conventional pipe replacement method, as mentioned above, the existing pipe and the new pipe are mainly replaced by excavation, which requires a great deal of time and effort for the replacement work. In short, there were issues that needed to be resolved, such as an increase in the cost of replacing the pipeline.

The present invention was made in order to solve the above-mentioned problems, and provides a pipe replacement method that can easily replace an existing pipe with a new pipe at low cost without using excavation. The purpose is to

(Means for Solving the Problems) The pipeline replacement method of the present invention involves inserting a lead wire into the existing pipeline from the starting drag side to the reaching drag side, fixing the tip of the lead wire to the reaching drag side, On the other hand, a new conduit having a diameter larger than that of the existing conduit is placed concentrically around the outer circumference of the existing conduit on the starting gate side, and a stopper member is fixed so as to close the end of this new conduit. pulling the lead wire from the starting side and applying a pressing force to the newly installed conduit through the abutment member using the reaction force;
The new pipeline is moved underground to replace the existing pipeline with the new pipeline.

(Function) In the pipe replacement method of the present invention, when a lead wire is inserted into the existing pipe and one end of which is fixed on the reaching side is pulled on the starting side,
The reaction force generated during the pulling presses the end of the newly installed pipeline via the abutment member. As a result, the new pipeline will be propelled underground, and a new pipeline with a larger diameter (capacity) will be laid around the outer periphery of the existing pipeline. Thereafter, by pulling out and removing the existing pipeline from the starting shaft or the arrival shaft, it can be replaced with a new pipeline without excavating the existing pipeline buried underground.

(Example) Hereinafter, an example of the pipe replacement method according to the present invention will be described with reference to the drawings.

FIGS. 1 and 2 are schematic diagrams for explaining the pipe replacement method of the present invention.

In these figures, l is a starting shaft excavated underground, and 2 is a reaching shaft excavated at a certain distance from the starting shaft l. An existing pipeline 3 is buried between the starting shaft 1 and the reaching shaft 2. If the existing pipeline 3 becomes unusable or needs to be replaced with a new pipeline due to lack of capacity, etc., excavation is carried out around the entire length of the existing pipeline 3 buried underground 10. Instead, replace it with the newly installed conduit 4 as follows.

That is, first, the lead wire 5 as a pilot is inserted into the existing pipe line 3 from the starting shaft 1 side to the arrival shaft 2 side. As this lead wire 5, for example, a piano wire is used. Also,
If there is content in the existing pipe 3, insert a small diameter pipe, for example, about 50 mmφ, from the starting shaft 1 side to the arrival shaft 2 side in advance using horizontal poling, and insert a lead wire into this small diameter pipe. Make sure to insert 5.

Next, the tip end of the lead wire 5 led out to the reaching hole 2 side is fixed to a lid member 6 arranged so as to close the end of the existing pipe line 3 on the reaching hole 2 side. Alternatively, as shown in FIG. 2, an earth anchor is driven into the side wall of the reaching shaft 2, and the tip of the lead wire 5 is fixed to this earth anchor 7.

Next, a new conduit 4 to be laid on the starting gate 1 side.
is arranged concentrically with the existing conduit 3 so that its central axis is aligned, and the end of the new conduit 4 is closed with a stopper member 8. In addition,
The pipe diameter of the new pipe line 4 is relatively larger than the pipe diameter of the existing pipe line 3.

Next, a pressing member 9 is arranged so as to come into contact with the outer periphery of the abutting member 8 on the side of the starting resist 1, and the lead wire 5 is pulled in the six directions of the arrows. For example, a hydraulic wire winding device (not shown)
is installed on the starting resistor 1 side, and by winding up the lead wire 5 with this hydraulic wire winding device or the like, the reaction force against the tensile force of the lead wire 5 is transmitted to the abutting member 8 via the suppressing member 9. .

Therefore, the newly installed conduit 4 is pressed in the direction of arrow B by this contact member 8, and the newly installed conduit 4 is propelled forward (in the direction of arrow B). In addition, if the reaction force obtained by pulling the lead wire 5 or winding it with the wire winding device is insufficient for digging ability, a hydraulic jack or the like is installed on the starting shaft 1 side as a propulsion auxiliary device. Newly installed conduit 4 via abutting member 8
promote. The length of the existing pipeline 3 is 100 to 150 m.
When the length of the newly installed pipeline 4 is 2 m, a large number of newly installed pipelines 4 are promoted in the same manner as described above.

Thereafter, when the newly constructed pipeline 4 that was first propelled reaches the arrival shaft 2 side, the existing pipeline 3 is removed from the starting shaft 1 side or the arrival shaft 2 side, and the pipeline replacement is completed.

(Effects of the Invention) As explained above, the pipeline replacement method of the present invention is capable of propelling a newly constructed pipeline underground using the reaction force corresponding to the tensile force caused by pulling or winding the lead wire. So,
New pipes can be replaced without excavating the underground where the existing pipes are buried. Therefore, the period for replacing the newly installed pipeline can be significantly shortened, and the cost for replacing the pipeline can be reduced. Additionally, by arranging the lead wire on the central axis of the existing pipeline and propelling the new pipeline coaxially with the existing pipeline, excavation accuracy can be significantly improved. .

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are schematic explanatory views for respectively explaining the pipe replacement method of the present invention. 1-1----------Starting shaft, 2-------1--Arriving shaft, 3--------1---Existing pipeline, 4 ---One--
-----------New conduit, 5-----Lead wire, 6--------Cover member, 7-- ------Earth anchor 8-1--
----------Application member, 9----------1-
-Press member, 0-------1---underground.

Claims (1)

[Claims] Insert the lead wire into the existing pipeline from the starting side to the reaching side, fix the tip of the lead wire to the reaching side, and
A new conduit having a larger diameter than the existing conduit is arranged concentrically around the outer periphery of the existing conduit on the starting point side, a stopper member is fixed so as to close the end of the new conduit, and the lead wire is is towed from the starting side, and the reaction force applies a pressing force to the new conduit through the abutment member, and the new conduit is propelled underground to replace the existing conduit with the new conduit. This pipe replacement method is characterized by: