JPH0472958B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method for repairing a pilot tube.

<Conventional Technology> When piping humid pipes or steel pipes underground where excavation is difficult, such as in densely populated residential areas, the propulsion method is employed.

In this construction method, a separate pipe (pilot pipe) is connected to the tail end of an excavator equipped with excavation means, and the pipe is propelled underground.

A particular problem with the propulsion method is the correction of the propulsion direction when the pilot pipe meanderes.
Conventionally, as a means of correcting the propulsion direction, a plurality of direction correction jacks are interposed between the excavation machine and the pilot pipe, and by expanding and contracting these direction correction jacks, the excavation machine can be adjusted as planned. There is a way to correct the lines.

<Problems to be Solved by the Present Invention> The above-described pilot tube repair method has the following problems.

(b) During propulsion, the direction of propulsion can be corrected to some extent using a direction correction jack, etc., as described above, but it is technically very difficult to accurately correct the displacement and penetrate.

Therefore, once the pilot tube passes through the pilot tube in a meandering manner, it is impossible to correct the displacement of the pilot tube.

Furthermore, when the amount of displacement of the pilot tube is large, the propulsion operation must be repeated again.

(b) If the pilot tube has a small diameter and cannot be equipped with devices to correct the direction during propulsion, it is expected that the amount of displacement of the pilot tube will be large.

Furthermore, when the propulsion distance becomes long, the amount of displacement from the planned line tends to increase.

Therefore, during propulsion work, there are restrictions on the ground and distance of propulsion.

(c) When equipped with a jacking device for direction correction, these devices become complicated and troubles such as breakdowns are likely to occur.

<Object of the present invention> The present invention has been made in order to solve the above-mentioned problems. The purpose of this invention is to provide a method for repairing a pilot tube.

<Structure of the present invention> An embodiment of the present invention will be described below with reference to the drawings.

<1> Propulsion of pilot tube (Figure 2) The propulsion device 1 is set in the starting shaft A.

A leading pipe 2 into which a multi-drill is inserted is connected to this propulsion device 1, and rotational force and propulsive force are applied to this leading pipe 2 to start digging.

Further, a pilot pipe 3 made of steel pipe with a screw auger 31 inserted therein is successively connected to the tail end of the leading pipe 2 to proceed with the excavation work.

In order to propel the pilot pipe 3, other than the method shown in this embodiment in which the pilot tube 3 is propelled while being excavated with an auger, a method of penetrating the pipe while being compacted can be adopted.

Propulsion is continued using any of the above propulsion methods to penetrate until reaching shaft B.

In this embodiment, a case where the pilot tube 3 meandered downward from the planned line C will be explained.

<2> Connecting the pilot pipe with a bit (Fig. 3) Remove the leading pipe 2, multi-drill, and screw auger 31 exposed in the reaching shaft B.

Next, the pilot pipe 3 exposed in the reaching shaft B
A separate pilot tube 4 with a bit is connected to the tip of the tube.

This pilot tube 4 with a bit is a tube body formed by implanting a bit 41 in a part of the outer periphery, as shown in FIG.

The number of bits 41 to be planted may be one or more.

In short, as will be described later, it is sufficient if the pilot tube 4 with the bit is given a swinging motion to excavate the earth and sand located in the correcting direction.

Also, instead of the pilot tube 4 with a bit,
It is also possible to attach the bit 41 to the outer periphery of the pilot pipe 3 exposed in the reaching shaft B by welding or the like.

<3> Direction correction by oscillating excavation (Figs. 4 and 5) When connecting the pilot pipe 4 with a bit, connect the bit 41 with the bit 41 facing the correction direction.

Alternatively, after welding the bit 41 first, rotate the pilot tube 4 with the bit to weld the bit 41.
1 in the correction direction and stand still.

In the case of the present embodiment, since the bit 41 is meandering downward, it stands still with the bit 41 facing upward.

Next, the pilot pipe 3 is pulled back toward the starting shaft A side while being given a rocking motion from its base end.

At this time, the free end of the bit-equipped pilot tube 4 exposed in the reaching shaft B is moved in the correction direction.

The pilot tube 4 with a bit can be moved in the correcting direction by, for example, lifting it up with a chain block or pushing it up with a jacking device.

As a result, the pilot pipe 4 with the bit approaches the planned line C while excavating the earth and sand located in the correction direction by the swinging of the bit 41.

Since the earth and sand excavated by the bit 41 moves into the void created by the movement of the pilot pipe 4 with the bit, there is no need to specifically remove the earth.

In parallel with the connection work of the new pilot pipe 4 with a bit on the arrival shaft B side, the pulled back pilot pipes 3 are sequentially removed from the starting shaft A side.

The above steps are repeated to align the axes of the pilot tube A with bits and the pilot tube 3 with the planned line C, and the correction work is completed.

<Other Embodiments> In the above embodiments, the method for correcting the meandering of the front portion of the pilot tube 3 has been described, but if the central portion of the pilot tube 3 meanders, the following operation is performed to correct the meandering.

That is, the pilot tube 4 with a bit is connected to the tip of the pilot tube 3 that has passed through it, and is extended until the pilot tube 4 with a bit is located at the center.

Next, after arranging the bit 41 facing the correction direction, the pilot pipe 3 is given a swinging motion to excavate the earth and sand located on the correction direction side.

At this time, if a tensile or compressive force is applied to the ends of both pilot pipes 3 and 4 exposed to the starting shaft A and the reaching shaft B, the displacement of the pilot pipe 3 can be easily corrected.

Furthermore, the above description describes the case where the distance to be corrected is small, and although it depends on the geology, the distance to be constructed, and the skill level of the workers, on a normal site, corrections are almost completed by pulling back once. do.

However, if the direction is greatly deviated and the distance to be corrected is large compared to the height of the bit, it is difficult to correct it by pulling back only once.

In such a case, the pulling back to the starting shaft A and the forward movement to the reaching shaft B, accompanied by a rocking motion, are repeated, and the correction is gradually made.

2 to 5 show cases where the pilot tube 4 is largely displaced for convenience in order to facilitate understanding of the present invention, but in reality, the amount of displacement of the pilot tube 4 is often extremely small.

If the amount of displacement is extremely small, install a pilot tube 4 with a bit at the tip of the pilot tube 3 as shown in Figure 1.
In some cases, the problem can be solved by simply connecting one wire.

<Effects of the Present Invention> Since the present invention is as explained above, the following effects can be obtained.

<B> The meandering pilot pipe can be used as a guide member to move while excavating in the correction direction.

Therefore, even after the pilot tube has penetrated, the displacement of the pilot tube can be easily and accurately corrected.

<B> The excavated soil generated during correction of the pilot pipe displacement will be moved to the meandering space, so there is no need to specifically remove it.

Therefore, there is no fear of ground subsidence and work can be carried out safely.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of an embodiment of a method for correcting the displacement of a pilot tube, Figure 2: An explanatory diagram when the pilot tube is propelled, Figure 3: An explanatory diagram when the pilot tube with a bit is connected, Figure 4: Figure 5: Explanatory diagram when correcting displacement.

Claims (1)

[Scope of Claims] 1. A pilot tube is propelled through a predetermined section, and a pilot tube with a bit implanted on the outer periphery is attached to the tip of the pilot tube on the reached side, and the bit of the pilot tube is moved in the correcting direction. While applying a rocking motion to the pilot tube and a propulsive force to pull the pilot tube back toward the starting side, at the same time applying a biasing force in the correcting direction to the free end of the pilot tube, excavating the earth and sand located in the correcting direction. A method to correct a meandering pilot tube by moving the pilot tube to the planned line.