JPS6235190A - Method of replacement construction of old pipe by non-drive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a construction method for replacing buried pipes such as gas and water pipes with new pipes, which enables long-distance replacement without excavation and does not reduce the cross-sectional area. The purpose is to provide construction methods.

<Conventional Technology> Buried pipes such as gas pipes and water pipes need to be replaced with new pipes due to their age and other reasons.

This type of replacement work is normally carried out using the trenchless method, but in recent years it has become desirable to perform trenchless construction due to traffic conditions and other reasons.

The PIF method is known as a trenchless pipe replacement method that has a relatively good track record in Japan. This method involves inserting a new pipe into the old pipe to replace it, and while it is relatively easy to replace over long distances, it can only be replaced with a pipe of a smaller diameter than the old pipe, reducing the cross-sectional area. There are drawbacks that lead to

<Summary of the Invention> The present invention has been made in view of the current state of the prior art described above, and is intended to provide a construction method that allows relatively long-distance replacement and does not cause a reduction in cross-sectional area.

Prior to the present invention, the present applicant had proposed a trenchless long-distance excavation method in Japanese Patent Laid-Open No. 11297/1983. This method involves forming a pilot hole with a pilot pipe from one shaft to the other shaft, then attaching a hole expanding bit to the pilot pipe and expanding the pilot hole from the other shaft to the other shaft. Tsutsu.

This method involves inserting pipes. According to this method, since the pilot hole is first formed, horizontal straightness is good and long-distance excavation is possible.

The present invention creates a new construction method by applying this proposed excavation construction method to the replacement of old pipes.

That is, in the construction method of the present invention, first, vertical shafts are dug at both ends of the IS pipe to be replaced, and both ends are exposed and then cut. Then, the old pipe is used as a pilot hole, and a pilot pipe is inserted from one shaft in the direction of the old pipe and penetrates to the other shaft.

At this point, attach a hole expanding bit to the tip of the pilot tube.

Then press the tip of the hole-expanding bit against the new tube to be replaced, and press-fit the new tube while expanding the hole with the bit. This pressing force simultaneously pushes out the old pipe through the bit. Insert a swivel joint etc. between the hole expansion bit and the new and old pipes,
To be able to transmit pressing force while ensuring the rotation of a hole-expanding bit. This allows extrusion and hole expansion of the old pipe and insertion of the new pipe at the same time.

Once the replacement is complete, connect both ends of the new pipe to the old pipe that will not be replaced to complete the work.

<Embodiment of the Invention> The construction method of the present invention will be described below based on an illustrative embodiment.

First, the vertical shaft (A), (
Dig B), expose the tube (X), and cut it. And pilot pipe (1) from one shaft (A)
into the old pipe (X) and make its tip protrude into the other shaft (B). The pilot pipe (1) is connected to an excavator (3) installed in the vertical shaft (A) and receives rotational force.

A hole expanding bit (2) is attached to the tip of the pilot pipe (1) in the shaft (B). A swivel joint (4) is provided at the tip of the hole expanding bit (2). A swivel joint or reamer (5) is also attached to the rear end of the bit (2) so that it comes into rotational contact with the end of the old tube (X).

The above-mentioned pilot pipe (1), hole expansion pit (2), excavator (3), and swivel joint (4) are the same as the above-mentioned Japanese Patent Application Laid-Open Nos. 58-11297 and 1983, which were proposed by the applicant. -122698 is used.

After completing the above preparations, connect the new pipe (Z) to the swivel joint (4) and install the hydraulic jack (6). (60) is the reaction plate. Then, as shown in FIG. 2, the new pipe (2) is pressed by the hydraulic jack (6) while the hole is expanded by the hole expansion bit (2). At the same time, the pilot pipe (1) is pulled toward the shaft (A) by the excavator (3) and moved in the direction of the shaft (A). Hydraulic jack (
The pressing force of 6) is swivel joint (4 in), bit (2 in)
), reamer etc. (5) to suppress the old pipe (X)'E: and push it out to the shaft (A) side.

After advancing a predetermined distance, the extruded old pipe (X) is cut and removed as shown in Fig. 3.

At the same time, the pilot pipe (1) is also removed by the same length. Then, a new pipe (Z) of a predetermined size is added by welding and pushed in using a hydraulic jack (6).

After that, repeat the same operation and replace the old pipe (X) with the new pipe (Z). Thereafter, as shown in FIG. 4, both ends of the new pipe (Z) are welded to the remaining old pipe (X') that will not be replaced, completing the replacement work. Shafts (A) and (B) will be filled after the work is completed.

Note that the hole expansion bit (2) is provided with a soil discharge pipe (7), and the discharge accompanying the hole expansion is discharged to the shaft (B) side through this pipe. Furthermore, an anti-friction agent injection device (c) is provided to inject an anti-friction agent into the soil around the cylinder during hole expansion, thereby reducing the pressing force.

A swivel joint or reamer (5) interposed between the hole expansion bit (21 and the old pipe (X)) transmits pressing force to the old pipe (X) and rotates the bit (2). It is fine as long as it does not restrict the structure.

An example is shown in FIG. In this example, the hole reaming bit (2
) or the end of the pilot tube (1) is fitted with a sleeve (51) and secured with a stopper (50). Then, the bearing (5) is placed on this sleeve (51).
2) A bearing housing (53) is fitted through F, and this housing (53) is structured to abut against the end of the old pipe (X). As a result, the bit (2) presses the housing (53) while rotating via the bearing (52) f, and this pressing force is transmitted to the old pipe (X).

<Effects of the Invention> As explained above, according to the method of the present invention, it becomes possible to replace long-distance buried pipes without digging, and it also becomes possible to replace them with new pipes that have a larger diameter than the old pipes. In addition, it is possible to replace old pipes and new pipes at the same time in one operation, which improves work efficiency. In addition, since the old pipe is pushed out by press-fitting the new pipe, the power unit can be simple and lightweight.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory diagrams showing the types of work performed by the method of the present invention, and Figure 5
The figure is a partial sectional view showing an example of the structure of a reamer or the like. (1)... Pilot pipe, (2)... Hole expansion bit,
(3)...Excavator% (4)...Swivel joint, (5)...Reamer, etc., (6)...Hydraulic jack.

Claims (1)

[Claims] Form a vertical shaft at both ends of the old pipe to be replaced, Cut the old pipe to expose both ends, Insert the pilot pipe into the old pipe from one shaft. through the shaft to the other shaft, and the pyro Attach a hole expanding bit to the tip of the cut tube, Touch the new pipe to the tip of the hole expansion bit and expand the hole. Enlarge the hole with a hole bit and press fit the new pipe. At the same time, push out the old tube through the bit, After the old pipe and new pipe have been replaced, both ends of the new pipe are Each is characterized by being connected to non-replaceable old pipes. A trenchless method for replacing old pipes.