JPH07293193A - Underground propulsion device and its method - Google Patents

Abstract

PURPOSE:To replace an excavation bit in a short time at low cost in the underground propulsion method employing a propulsion device having a double pipe structure. CONSTITUTION:Propulsion force is given to a propelling pipe 5 by a propulsion machine 3 located in a starting shaft 2, and an inner pipe 7 in the propelling pipe is thereby rotated. An excavation bit at the tip end of the inner pipe is pushed by the propelling pipe for cutting in the ground. A shutter 9 closing the inner pipe is located forward inside the inner pipe 7. A feed pipe 13 for soil improving agent is disposed at the center of the inner pipe 7 along its axis, so that the soil improving agent is injected forward through a gap of a closed shutter plate 10. The inner pipe 7 is pulled back while being rotated until the excavation bit has been housed in the propelling pipe 5 after the shutter has been closed, and the soil improving agent is fed to a work face out of the feed pipe 13. After earth and sand in the propelling pipe and the inner pipe have been hardened, the inner pipe 7 is pulled out in order to the starting shaft 2 side so as to be recovered. The earth and sand inside the tip end of the propelling pipe have been hardened by the soil improving agent, and it will never collapse. All of the inner pipe are pulled out, and the excavation bit 8 is then recovered. After the excavation bit has been replaced, the underground propulsion device is restarted in a reverse procedure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion pipe that is press-fitted into the ground, an inner pipe that is inserted into the propulsion pipe to rotate, and an earth pipe is attached to the tip of the inner pipe to excavate the ground in front of the propulsion pipe. The present invention relates to an improvement of an underground propulsion device including an excavation bit, and further relates to an underground propulsion method using the underground propulsion device.

[0002]

2. Description of the Related Art A propulsion method for propelling a propulsion pipe in the ground to construct a pipeline is classified into various types according to a difference between an original pushing mechanism, an excavation method, and an earth discharging method. FIG. 5 is a cross-sectional view illustrating a propulsion method using a conventional double-pipe structure propulsion device, which is a type of such propulsion method.

An underground propulsion device 1 is provided inside the starting shaft 100.
01 propulsion device 102 is installed. The propulsion means of the propulsion unit 102 is connected to the base end of the propulsion pipe 103.
To the rotating means of the propulsion device 102, a base end portion of an inner pipe 104 inserted inside the propulsion pipe 103 is connected. Inner tube 1
A drill bit 105 is provided at the tip of 04.
The drill bit 105 is arranged in front of the tip of the propulsion pipe 103. The inner pipe 104 is rotated inside the propulsion pipe 103, the propulsion pipe 103 is propelled into the ground, and the excavation bit 105 is cut into the ground to excavate.

In the above propulsion method, if the excavation bit 105 is worn or damaged during propulsion, the excavation bit 10
It becomes necessary to replace 5. However, the ground propulsion device 1 with the double pipe structure is used for the ground that has groundwater and is likely to collapse.
To replace the drill bit 105 when propelling with 01, replace the drill bit 105 and inner pipe 104 with the propeller pipe 1
It is necessary to prevent the face from collapsing even if it is pulled out from 03.

Conventionally, the ground in front of the excavation bit 105 has been improved in order to replace the excavation bit 105. That is,
A hole 107 is formed in the ground from the ground surface 106 by a boring machine, and the propulsion pipe 10 is formed from the hole 107 as shown in the figure.
Ground improvement material is injected into the front part of 3 to cover a large area 10
8 was solidified to prevent the face from collapsing when the drill bit 105 was pulled out.

In the propulsion method, the excavation bit is selected according to the ground to be excavated. However, when the target soil contains large gravel, the excavation bit is worn or damaged and the useful distance of the excavation bit is reduced. It becomes shorter and requires replacement each time. When it is necessary to replace it, the excavation bit is pulled back to the starting shaft side, but if the cutting face is under water pressure or the ground is highly collapsible, at the same time when the excavation bit is pulled back, earth and sand will flow into the propulsion pipe, causing a collapse accident. It may occur. For this reason, the cutting face was bored from the ground surface to inject a soil improvement material to solidify it, and then the collapse of the cutting face was suppressed and the excavation bit was pulled back to replace the bit. In this method, since the work will be performed in preparation for ground improvement when the excavation bit needs to be replaced, the propulsion work must be suspended and the work must be waited.

[0007]

The above-mentioned ground improvement requires a lot of days and a huge cost for preparation and work. During the ground improvement work, the propulsion work must be interrupted, and the construction cost will be further increased due to the stand-by of construction equipment and personnel.

If the effect of ground improvement is insufficient,
The face collapsed when the drill bit was pulled back into the propulsion pipe,
There is a risk of a ground depression. On the other hand, if the ground improvement effect is too high, problems occur such that the periphery of the propulsion pipe is solidified and it cannot be propelled.

An object of the present invention is to improve a ground effectively with a small amount of ground improvement material in a propulsion method using a double pipe structure propulsion device, and to enable excavation bits to be replaced in a short time. There is.

[0010]

A submersible propulsion apparatus according to the present invention is a propulsion pipe that is pressed into the ground, an inner pipe that is inserted into the propulsion pipe to rotate, and a propulsion device that is attached to the tip of the inner pipe. The ground improvement material is injected in front of the drilling bit rotating in front of the pipe, the inner pipe closing means provided inside the inner pipe, and the closing means arranged and closed inside the inner pipe. It is characterized by being provided with a ground improvement material injection means for solidifying the soil in the propulsion pipe.

The underground propulsion device according to a second aspect of the present invention is the underground propulsion device according to the first aspect, wherein each of the propulsion pipe and the inner pipe comprises a plurality of propulsion pipes and an inner pipe. The propulsion and the rotation of the inner pipe are performed by a propulsion device provided in the starting shaft.

An underground propulsion device according to a third aspect of the present invention is the underground propulsion device according to the second aspect, wherein the ground improvement material injection means is a ground improvement material supply means provided in the starting shaft. And a supply pipe connected to the ground improvement material supply means, the supply pipe being arranged in the inner pipe.

A subsurface propulsion method according to a fourth aspect is the subsurface propulsion method using the subsurface propulsion apparatus according to the first aspect, wherein the propulsion is temporarily stopped during the propulsion and the closing means is closed,
Pull the inner pipe to pull the drill bit into the propulsion pipe, inject the soil improvement material in front of the closing means to solidify the soil in the propulsion pipe, and further pull the drill bit into the soil improvement material to solidify the interior of the propulsion pipe. The excavation bit is collected on the starting side of the propulsion pipe by filling it with the ground improvement material to cope with the face pressure and suppressing the soil and sand that flow into the propulsion pipe, and after exchanging the excavation bit, the excavation bit and the inner pipe again. Is to be inserted inside the propulsion pipe to restart excavation.

[0014]

The function of the inner pipe is closed by the closing means. The ground improvement material is supplied to the front of the closing means by the ground improvement material supply means while pulling the inner pipe toward the starting shaft until the drill bit is drawn into the propulsion pipe. The earth and sand filled inside the tip of the propulsion pipe is solidified by the ground improvement material and does not collapse. However, in most cases, the face is under water pressure, etc., and solidification within such a range is often insufficient. Furthermore, the ground improvement material was injected while pulling in the excavation bit to solidify the specified range within the propulsion pipe. It is filled with ground improvement material to prevent collapse in response to face pressure. The drill bit is pulled out of the propulsion pipe, replaced, and inserted again into the propulsion pipe, and the excavation is restarted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. First, the configuration of the underground propulsion apparatus 1 used in this embodiment will be described. An underground propulsion device 1 is installed inside the starting shaft 2.
The propulsion device 3 is installed. The propulsion unit 3 has a propulsion unit including a hydraulic cylinder 4 and the like. The base end of the propulsion pipe 5 is connected to this propulsion means. The propulsion unit 3 has a rotating means including a hydraulic motor 6 and the like. The base end of the inner pipe 7 inserted into the propulsion pipe 5 is connected to the rotating means.

The propulsion pipe 5 and the inner pipe 7 are formed by sequentially connecting a plurality of propulsion pipes and inner pipes of a predetermined length with each other as the propulsion process progresses.

A drill bit 8 is attached to the tip of the inner pipe 7. The excavation bit 8 is swingable between an excavation position outside the outer peripheral surface of the propulsion pipe 5 and a storage position inside thereof. When excavating the excavating bit 8 or the like, if the inner pipe 7 is pulled toward the starting shaft 2, the excavating bit 8 retracts to the storage position and is drawn into the propulsion pipe 5. When excavating, the excavating bit 8 is the inner pipe 7
Is pressed to set the excavation position. If the inner pipe 7 is rotated inside the propulsion pipe 5 and a propulsive force is applied to the propulsion pipe 5 by an operation on the side of the starting shaft 2, the excavating bit 8 excavates the face and the propulsion pipe 5 propels it.

On the front inner surface of the inner pipe 7, there is provided a shutter 9 as a closing means for closing the discharge of the excavated earth and sand. The shutter 9 includes two opening closing plates 10,
10 and a hydraulic jack 11 as a driving means for opening and closing the opening closing plate 10. Shutter 9
The operation of can be performed on the side of the starting shaft 2.

The underground propulsion device 1 is a ground improvement material injection means 1
Have two. The ground improvement material injecting means 12 has a ground improvement material supply means provided inside the starting shaft 2 or on the ground, and a ground improvement material supply pipe 13 arranged inside the inner pipe 7. The ground improvement material supply means has a storage tank for the ground improvement material, a supply pump for sending the ground improvement material in the storage tank to the face through the propulsion device 3, and a pipe 13a.

The ground improvement material supply pipe 13 is arranged in the center of the inner pipe 7 along the central axis. The supply pipe 13 extends forward from the gap between the closed opening-portion closing plates 10 so that the supply pipe 13 is not crushed by closing the shutter 9 and does not hinder the supply of the ground improvement material. Supply pipe 1
The tip portion of 3 projects forward from the front ends of the inner pipe 7 and the propulsion pipe 5, and is located in the vicinity of the drill bit 8.

For the soil improvement material of this embodiment, an instantaneous solidifying agent or the like which solidifies the earth and sand almost instantaneously can be used.

Next, a procedure for exchanging the excavating bit 8 in the underground propulsion method using the underground propulsion apparatus 1 will be described. As shown in FIG. 1, when excavation bit 8 needs to be replaced during propulsion, excavation is temporarily stopped.

As shown in FIG. 2, the shutter 9 is closed and the inner tube 7 is closed. The excavated earth and sand accumulate in front of the closed shutter 9. Drill bit 8 is propulsion pipe 5
The inner pipe 7 is rotated and pulled back to the side of the starting shaft 2 until it fits in the inside storage position, and at the same time, the ground improvement material is supplied to the cutting face via the supply pipe 13.

The ground improvement material supplied from the supply pipe 13 is
The inside of the inner pipe 7 in front of the shutter 9 and the inside of the propulsion pipe 5 in front of the drill bit 8 are filled. Considering the water pressure in the face, how much the range of the propulsion pipe 5 to be filled with the ground improvement material should be, that is, how much the excavation bit 8 should be pulled into the propulsion pipe 5 before the ground improvement material is injected. And adjust accordingly.

As shown in FIG. 3, not only the earth and sand 20 at the tip of the propulsion pipe 5, but also the earth and sand 2 in the space between the tip of the inner pipe 7, that is, the tip of the excavation bit 8 and the shutter 9.
1 is also solidified by the ground improvement material, but there is no problem because the inside of the inner pipe 7 can be removed when it is pulled back to the starting shaft 2 side.

As shown in FIG. 3, when the earth and sand 20 inside the tip portion of the propulsion pipe 5 is solidified by the ground improvement material, the inner pipe 7 is sequentially withdrawn toward the starting shaft 2 and collected.

The excavation bit 8 is collected. As shown in FIG. 4, all the inner pipes 7 are pulled out from the inside of the propulsion pipe 5 buried in the ground. Since the inside of the tip of the propulsion pipe 5 is solidified by the ground improvement material, it does not collapse due to the pressure of the cutting face. The recovered excavation bit 8 is carried out of the starting shaft 2 and replaced. The excavation bit 8 and the inner pipe 7 are inserted into the propulsion pipe 5 in the reverse process of pulling them out, and the exchanged excavation bit 8 is set in the vicinity of the solidified sand in the propulsion pipe 5.

Propulsion tube 5 filled with ground improvement material and solidified
The earth and sand 20 and the like inside is inserted while being broken by the excavation bit 8 that is rotationally driven as the inner pipe 7 is inserted, set to the position before extraction, and then normal propulsion is resumed.

In the embodiment described above, only the earth and sand 20 inside the tip portion of the propulsion pipe 5 is solidified with the ground improvement material, but depending on the strength of the ground, etc. Instead, the ground outside the propulsion pipe 5 close to the tip of the propulsion pipe 5 may be simultaneously improved.

It goes without saying that the underground propulsion apparatus 1 described in the present embodiment is merely an example of the underground propulsion apparatus to which the excavating bit 8 replacement method of the present embodiment is applied. For example, the shutter 9 which is a means for closing the inner pipe 7 does not have a structure having the opening closing plate 10, but is provided with an auger provided in the propulsion pipe for discharging excavated earth and sand and an excavating bit set at the tip of the auger. It can be adopted in a mechanism for excavating and propelling the propulsion pipe, and the structure may be such that the ground improvement material supply pipe 13 is arranged in the shaft of the auger and injected at the excavation bit part, or the structure of the auger shaft is used as the supply pipe. But it's okay. Furthermore, as a means of closing the tip of the propulsion pipe,
You may use the bag body which expand | swells by the gas supplied as needed and closes the inside of the inner pipe 7. Further, in the above-described embodiment, the ground improvement material is injected in front of the opening closing plate 10 by one supply pipe 13, but such a configuration is an example, and in short, the ground improvement material is provided in front of the closed closing means. Any structure may be used as long as the material can be injected to solidify at least the accumulated earth and sand inside the propulsion pipe.

[0031]

According to the underground propulsion apparatus and the underground propulsion method using the same of the present invention, the inside of the tip portion of the propulsion pipe can be solidified with a small amount of the ground improvement material during the propulsion.

Therefore, according to the apparatus and method of the present invention, it is possible to pull out the excavating bit and replace the excavating bit without breaking the face and in a very short time and without extra cost. Therefore, the number of days required for preparation and work for ground improvement of the propulsion pipe face and the propulsion work waiting for the work can be saved, but can be omitted.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an underground propulsion device and an underground propulsion method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an underground propulsion device and an underground propulsion method according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an underground propulsion device and an underground propulsion method according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an underground propulsion device and an underground propulsion method according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a conventional underground propulsion device and a conventional underground propulsion method.

[Explanation of symbols]

 1 Underground propulsion device 3 Propulsion device 5 Propulsion pipe 7 Inner pipe 8 Excavation bit 9 Shutter as a closing means 12 Ground improvement material injection means 13 Supply pipe which is a part of ground improvement material injection means

Claims (4)

[Claims] 1. A propulsion pipe that is press-fitted into the ground, an inner pipe that is inserted into the propulsion pipe to rotate, a drill bit that is attached to the tip of the inner pipe and that rotates in front of the propulsion pipe, and the inside of the inner pipe. And a ground improvement material injecting means for injecting the ground improvement material in front of the closing means disposed inside the inner tube and closed to solidify the earth and sand in the propulsion pipe. Underground propulsion device. 2. The propulsion pipe and the inner pipe each include a plurality of propulsion pipes and an inner pipe, and the propulsion of the propulsion pipe and the rotation of the inner pipe are performed by a propulsion device provided in a starting shaft. Underground propulsion device. 3. The ground improvement material injection means includes a ground improvement material supply means provided in the starting shaft and a supply pipe arranged in the inner pipe and connected to the ground improvement material supply means. The ground propulsion apparatus according to claim 3, which is configured. 4. The underground propulsion method using the underground propulsion device according to claim 1, wherein the propulsion is temporarily stopped during the propulsion to close the closing means, and the inner pipe is pulled to draw the drill bit into the propulsion pipe. At the same time, the ground improvement material is injected in front of the closing means to solidify the soil in the propulsion pipe, and the ground improvement material is injected while pulling in the excavation bit to fill the interior of the propulsion pipe with the solid ground improvement material to cope with the face pressure. The excavation bit is collected on the starting side of the propulsion pipe by suppressing the sediment that flows into the propulsion pipe, the excavation bit is replaced, and then the excavation bit and the inner pipe are inserted into the propulsion pipe again to resume excavation. Underground propulsion method characterized by: