JPH04161695A - Jacking method of embedded pipe - Google Patents

Abstract

PURPOSE:To improve the efficiency of embedding a pipe by composing a propeller shaft body of an excavator of a double pipe to use an outside pipe line for supplying pressurized water and an inside pipe line for draining excavated earth and sand in a muddy water pressurizing engineering method. CONSTITUTION:A propeller shaft body 30 of an excavator 10 for laying a buried pipe 70 formed of vinyl chloride pipe or the like is composed of double pipes to form an inside pipe line 32 and outside pipe line 34 fixed to the inside of the buried pipe 70 by a holding means 40 provided with a tubular expansible body 42. Next, while pressurized muddy water is supplied from the outside pipe line 34 to an earth and sand taking-in chamber 14 at the tip, the excavated earth and sand are expelled from the inside pipe line 32. While the propeller shaft body 30 is pushed out by a jack as the excavation proceeds, the buried pipe 70 is added, so that the efficiency of execution can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for promoting underground pipes, and more specifically, when constructing underground pipes for sewerage, etc. This relates to a so-called propulsion method in which a buried pipe is sequentially advanced and buried into the formed buried hole while forming a hole.

[Conventional technology]

A method for advancing underground pipes is to use an excavator equipped with an auger or other excavation mechanism at the tip to excavate a hole underground, and then proceed to push and bury the underground pipe as the excavator advances the excavation. This construction method is called the auger construction method. Furthermore, in recent years, consideration has been given to using PVC pipes and reinforced plastic pipes, which are lightweight, non-corrosive, and inexpensive, as materials for buried pipes used in such propulsion methods.

In the conventional auger construction method, the underground pipes are sequentially connected to the rear of the excavator, and in the vertical shaft where propulsion begins, that is, the starting shaft, the last end of the underground pipe is pushed with a push jack, etc., and the underground pipe and the excavator at its tip are pushed. I was trying to promote it. However, with this method, all of the frictional resistance force applied from the ground to the buried pipe during propulsion and the excavation resistance force when excavating the ground with an excavator are transmitted backward through the joints between the buried pipes. Since it is concentrated at the rearmost end and opposes the propulsive force applied from the original push jack, an extremely large pressure or stress is generated on the end face of the buried pipe, especially at the rearmost end of the buried pipe. Therefore, if a material with low yield strength, such as a PVC pipe, is used as the buried pipe, the buried pipe will be deformed or damaged, so there is a problem that the PVC pipe or the like cannot be used. In particular, the longer the propulsion distance for continuous construction in one process, the greater the frictional resistance from the ground, and the greater the pressure and stress generated on the end face and tail of the buried pipe, so increasing the propulsion distance and increasing the construction efficiency. The more efforts are made to reduce construction costs, the more problems such as deformation and damage of the buried pipes become.

Therefore, the inventors of the present application researched a propulsion method that would not cause locally excessive pressure or stress at the tail end of a buried pipe, etc., and as a result, they invented the method described below, and previously applied for the patent application No. -1
Patent applications have been filed as No. 83271 etc.

In this method, drive shaft bodies made of steel pipes or the like are successively added to the rear of the excavator, and the tail end of the drive shaft is pushed by a pusher jack to propel the excavator. Further, the buried pipe is inserted into the outer periphery of the drive shaft body and added to the rear of the excavator, and the buried pipe is held and fixed to the drive shaft body inside the buried pipe. The buried pipe is propelled together with the drive shaft by the drive shaft. As means for holding and fixing the buried pipe to the drive shaft body, for example,
A structure is adopted in which an expandable body that expands when pressurized air is supplied is installed on the outer surface of the drive shaft body, and this expandable body is expanded and pressed against the inner surface of the buried pipe to hold and fix the buried pipe to the drive shaft body. be done.

In the above method, the excavation resistance force applied to the excavator is not transmitted to the buried pipe at all, but is opposed to the propulsive force from the main push jack via the drive shaft body. In addition, the frictional resistance of the ground that is applied to each buried pipe is also transmitted to the drive shaft inside the pipe.
The frictional resistance of other buried pipes will not be concentrated and transmitted to the joints between buried pipes or at the end of a row of buried pipes, and excessive pressure or stress will not be generated locally in the buried pipes. It disappears. As a result, it has become possible to use buried pipes with inferior strength, such as PVC pipes, in the propulsion method, and it has also become possible to significantly extend the propulsion distance in one process.

[Problem to be solved by the invention]

However, in addition to the auger method described above, conventional propulsion methods include a method called the muddy water pressurization method, which involves holding and fixing the buried pipe to the drive shaft body described above. The problem is that the method is difficult to adopt.

The muddy water pressurization method involves pumping water or muddy water into the excavated area using an excavator, and excavating while pressurizing the ground surface.
It has the advantage of making it easier to excavate the ground, preventing the ground from collapsing and gushing out underground water, and making the soil removal work easier because the excavated earth and sand are discharged together with muddy water. In this mud water pressurization method, two pipes are installed in the buried hole: a mud pipe to supply water and mud from the shaft to the tip of the excavator, and a mud drainage pipe to discharge excavated earth and sand and mud. You need to pass it inside.

However, as described above, if a structure is adopted in which the buried pipe is held and fixed on the drive shaft body, a means for holding and fixing the buried pipe will be installed in the space between the drive shaft body and the buried pipe. It becomes difficult to pass the mud feeding piping and mud drainage piping necessary for the mud water pressurization method described above. In general, mud feeding pipes only flow liquid water or muddy water, so they do not need to have a very large pipe diameter, but mud drainage pipes flow muddy water as well as clumped earth such as gravel, so they must have a sufficiently large diameter. Must have. Therefore, it is extremely difficult to install both the mud feeding pipe and the mud draining pipe at the same time as the holding and fixing means for the buried pipe between the drive shaft body and the buried pipe.

In particular, as a means for holding and fixing buried pipes, as mentioned above,
When using an inflatable body that is inflated with pressurized air, etc., in order to exert sufficient frictional holding force when pressed against the inner surface of a buried pipe, it is necessary for the inflatable body to come into contact with a wide area of the buried pipe. The volume occupied by the pipe becomes very large, and there is no room to install the mud feeding pipe and mud removal pipe described above.Furthermore, in order to securely hold and fix the buried pipe, it is necessary to connect the entire inner circumference of the buried pipe to the drive shaft. It is necessary to hold and fix it to the body, but if this is done, there will be no clearance at all to install the mud feeding pipe and the mud draining pipe.

Therefore, the problem of this invention is also in the muddy water pressurization method.
As mentioned above, by holding and fixing the buried pipe to the drive shaft body,
It is an object of the present invention to provide a method that makes it possible to apply a structure that prevents the generation of excessive pressure or stress on a buried pipe during propulsion.

[Means to solve the problem]

The buried pipe propulsion method according to the present invention solves the problem S mentioned above. In the underground pipe propulsion method, in which a propulsion force is applied to the shaft body to propel the excavator and the buried pipe into the buried hole, the propulsion shaft body is composed of a double pipe, and one of the inner and outer pipes of the double pipe is Water or mud is supplied to the excavator through one pipe to pressurize the ground, while earth and sand excavated by the excavator is discharged backward along with muddy water through the other pipe.

The excavator used is basically the same as the excavator used in the normal mud water pressurization method. Specifically, the front surface of the excavator is equipped with a cutter head for excavating the ground, and an excavation face plate called a canter disk or face plate.

The excavation face plate is rotationally driven by a motor or the like, and as the excavation face plate rotates, the ground is excavated. In conventional excavators, a drive source such as a motor that rotates the excavation face plate is installed in a shaft or on the ground surface, and the rotation of the drive source is transmitted to the excavation face plate inside the excavator via a drive shaft that passes through the center of the buried hole. However, in the present invention, the drive source is preferably located inside the excavator, such as immediately after the excavation face plate. This is because the drive shaft is used as piping and sludge drainage piping, so if the drive shaft is built into the propulsion shaft body, the pipe space will be reduced.Also,
If the drive source is located near the excavation face plate, the drive shaft can be shortened. However, the power cable, hydraulic cable, etc. for operating the motor may be connected to the rear shaft or the ground surface through the space between the propulsion shaft and the buried pipe.

The excavation face plate is provided with a soil discharge port called a slit to send the soil to the back, and this soil discharge port is a space also called a pressure chamber, mud room, etc. that is sealed with a partition wall, etc.
It is connected to the so-called intake room. A mud feeding pipe that supplies water and muddy water, and a mud drainage pipe that discharges earth and sand and muddy water are connected to this intake chamber. The pressure applied to the ground in front of and around the excavation face plate can be adjusted by appropriately setting the amount or pressure of water and mud sent to the intake chamber and the amount or pressure of soil and mud discharged. can.

In addition to the above structure, the excavator can be equipped with various mechanisms and structures similar to ordinary excavators, such as a direction correction jack for changing the excavation direction of the excavator and a laser surveying target for position surveying.

The propulsion shaft body is made of a double tube made of metal such as steel that has enough rigidity to withstand the propulsion force from the original pusher jack, and has two concentric inner and outer layers of conduit. The tip of the propulsion shaft body can be connected and fixed to the rear of the excavator using a flange or bolt, and the propulsion shaft bodies can be connected to each other in the axial direction. As the means for connecting and fixing the propulsion shaft body, a mechanism similar to the means for connecting and fixing the drive shaft body or the propulsion shaft in normal propulsion construction methods can be adopted. However, since water or muddy water and muddy water containing earth and sand flow through the dual pipes of the propulsion shaft, it is preferable to provide water sealing means for each pipe at the connecting part. As with normal piping, seal rubber and
Rings, seals, and other mechanisms can be used.

The leading end of the propulsion shaft is fixed to the excavator, and the double pipes of the propulsion shaft are connected to the partition wall of the intake chamber, respectively, and open into the intake chamber. At the rearmost end of the body, one pipe of the double pipe is connected to a water or muddy water supply device in a shaft, etc., and the other pipe is used to remove sand and water from muddy water containing sand. The water or mud water separated by the sediment and water separation device, which is connected to a device for separating, collecting sediment, and recirculating the separated water, can be returned to the supply device for recycling. .

Any of the dual inner and outer pipes of the propulsion shaft body may be used as the mud removal pipe or the mud removal pipe. In general, it is best to set mud removal piping, which requires a relatively large diameter in order to flush away lumps of earth and sand, in the inner pipe, and to set mud feeding piping, which allows water or muddy water to flow even in narrow gaps, in the outer pipe. preferable. The diameter ratio or cross-sectional area distribution of the inner and outer pipes of the double pipe can be determined arbitrarily, taking into account the difference in purpose of the mud removal pipe and the mud feeding pipe as mentioned above, the performance of the excavator, the construction conditions, etc. Can be set to .

The propulsion shaft body is provided with means for holding and fixing the buried pipe. As the means for holding and fixing the buried pipe, any means for fixing the pipe material in ordinary various mechanical devices can be used as long as the buried pipe is fixed so as to abut against the inner surface of the buried pipe so as not to move in the axial direction. For example, a bag-shaped inflatable body made of rubber or the like is provided on the outer surface of the propulsion shaft, and a pressure medium such as pressurized air, oil, or water is fed into the inflatable body to inflate it toward the outer periphery. If you press the expansion body against the inner surface of the buried pipe,
The buried pipe can be held and fixed to the propulsion shaft. Further, the propulsion shaft body may be provided with an engagement mechanism that presses a mechanically actuated pressing plate against the inner surface of the buried pipe or engages with the inner surface of the buried pipe and fixes it in the axial direction.

Regarding the detailed structure of the holding and fixing means for the buried pipe, see the above-mentioned Japanese Patent Application No. 1-183271 and Japanese Patent Application No. 1-240408.
The structure disclosed in Japanese Patent Application No. 63-298619, etc. can be adopted.

The holding and fixing means for the buried pipe is provided on the outer periphery of the propulsion shaft made of double pipes, so it can be installed by freely utilizing the space between the propulsion shaft and the buried pipe. The specific procedure and process of the propulsion method, which is preferable to provide a laser beam path for surveying between the pipes and to leave space for installation of cables and piping for supplying power, hydraulic pressure, etc. to the excavator, is described in the earlier application. It can basically be the same as the propulsion method disclosed in the patent.

In other words, the propulsion shaft, whose outer periphery is covered with a buried pipe and fixed with a holding and fixing means, is successively connected to the rear of the excavator and added to the machine, while applying propulsion force to the rear end of the propulsion shaft using a push jack. The excavator, propulsion shaft, and buried pipe will be propelled.

On the rear end side of the propulsion shaft, a mud feeding pipe for supplying water or muddy water is connected to one of the pipes of the double pipe, and supplies water or muddy water to the excavator through the propulsion shaft. The excavator excavates the ground by rotationally driving the excavation face plate, and applies pressure to the ground with water or muddy water supplied to the intake chamber. The excavated earth and sand are sent rearward along with muddy water through the other pipe of the propulsion shaft, and are discharged to the outside through a mud removal pipe connected to the rear end of the propulsion shaft.

By repeating the above steps, a buried hole is excavated and formed using an excavator, and the buried pipes are sequentially pushed and buried in the buried hole behind the excavator. Once the underground pipe has been buried to the desired shaft, the excavator and propulsion shaft will be disassembled and removed. By releasing the holding and fixing of the buried pipe by the holding and fixing means, only the propulsion shaft can be removed while leaving the buried pipe in the buried hole. Thereafter, the same post-processing work as in normal propulsion methods is carried out, such as appropriately treating the joints of the buried pipe and the exposed parts of the shaft, and the installation of the buried pipe is completed.

The underground pipe propulsion method according to the present invention is preferably used for construction of relatively small diameter buried pipes such as gas piping, underground electric cable piping, etc. in addition to the above-mentioned sewerage system, but it can also be used for any other purpose and diameter. It can be used for construction of underground pipes. In addition, as for the material of the buried pipe, PVC pipe or reinforced plastic pipe as mentioned above is preferably used.
Other tubing materials with similar problems can also be used.

[For production]

When a buried pipe is held and fixed to the propulsion shaft body that transmits the propulsion force to the excavator, the space between the buried pipe and the propulsion shaft body must be filled with mud feeding piping and mud drainage piping used in the mud water pressurization method. I can't.

However, if the propulsion shaft body is composed of a double pipe and the two layers of pipes inside and outside of this double pipe are used for the mud feeding pipe and the mud removal pipe, the installation structure of the holding and fixing means for the buried pipe can be completely changed. It is possible to install mud feeding piping and mud drainage piping without any impact.

Moreover, if the mud feeding piping and the mud draining piping are common to the propulsion shaft body, no special piping parts or piping connection work is required, and the construction equipment can be simplified and the construction work can be made more efficient.

〔Example〕

Next, embodiments of the invention will be described below with reference to the drawings.

Figure 1 shows the structure near the tip of the excavator of the construction equipment used in the propulsion construction method of the present invention. excavator 10
has a cylindrical outer shape that matches the diameter of the buried hole, and is equipped with an excavation face plate 20 on the front surface.

The excavation face plate 20 is equipped with an excavation mechanism such as a cag-bit 21 on the front side, and is also provided with a slit-shaped earth discharge port 22 for sending excavated earth and sand to the rear. The excavation face plate 20 is connected to a drive motor 2 via a drive shaft 24 provided at the center of the back surface.
6. The drive shaft 24 is supported by a partition wall 12 that partitions the inside of the excavator 10. The excavation face plate 20 is rotated by the rotational drive of the drive motor 26, the ground is excavated with the cutter bit 21, and the excavated earth and sand is delivered to the earth discharge port 22.
taken in backwards. The space between the excavation face plate 20 and the partition wall 12 becomes an intake chamber 14.

The excavator 10 is constructed by combining a front cylinder part 11 to which an excavation face plate 20 and a partition wall 12 are attached, and a rear cylinder part 16 to which a propulsion shaft body (to be described later) is fixed, with their ends partially overlapped. They are connected by telescopic direction adjustment jacks 15 provided at multiple locations. By changing the amount of expansion and contraction of the direction correction jack 15,
The central axis of the front cylinder part 11 can be tilted in any direction,
Thereby, the excavation direction of the excavator 10 can be corrected. A sealing means 17 such as a sealing material is provided at the overlapping portion of the front cylinder part 11 and the rear cylinder part 16.

A propulsion shaft body 30 is fixed to the rear cylinder portion 16 of the excavator 10 via a flange connection mechanism 19. Propulsion shaft body 30
is composed of a double pipe made of steel pipe or the like, and the outer pipe line 34 serves as a mud feeding pipe for flowing water or muddy water, and the inner pipe line 3
2 is the mud drainage pipe that drains the excavated earth and sand and muddy water.

At the tip of the propulsion shaft body 30, an extension pipe 84 made of a flexible hose or the like is connected to the outer surface of the outer pipe line 34, and the extension pipe 84 is connected to the partition wall 12 and opens into the intake chamber 14. . Further, an extension pipe 82 is also provided on the end face of the inner pipe line 32.
are connected and open to the intake chamber 14 via the partition wall 12.

Another propulsion shaft 30 is connected to the rear end of the propulsion shaft 30, and the propulsion shaft 30 is sequentially added to the rear. Figure 3 shows
The structure of the connecting portion between the propulsion shaft bodies 30 is shown. At the butt part of the outer tube 33.33 of the double tube, one outer tube 3
3 is attached with a flange 35 having a substantially S-shaped cross section,
A planar flange 36 is attached to the outer tube 33 facing this, and both flanges 35 and 36 are made to face each other and fixed by tightening with bolts 37. A sealing rubber 100 is attached to the opposing portion of the flange 35 having an S-shaped cross section and the outer peripheral surface of the other outer tube 33 to improve the water sealing performance of the joint portion of the outer tube 33. inner tube 31
．． At the abutting portion 31, a flange 38 having a truncated cross section is attached to one of the inner tubes 31. A seal rubber 100 is also installed at a location where this flange 38 faces the outer circumferential surface of the other inner tube 31 to provide a water seal between the inner pipe line 32 and the outer pipe line 34.

A buried pipe holding and fixing means 40 is attached to the outer periphery of the propulsion shaft body 30. As shown in FIG. 4, the holding and fixing means 40 is made of an elastic material such as rubber, and has an annular tube-shaped expansion body 42 with a flat oval cross section, and supports and propels this expansion body 42. Support member 44 fixed to shaft body 30
It consists of A supply pipe 46 for feeding pressurized air is connected to the expansion body 42 . When the expandable body 42 is filled with pressurized air, the expandable body 42 expands toward the outer circumference, and the outer surface of the expandable body 42 is pressed against the inner surface of the buried pipe 70 made of a PVC pipe or the like. When the expansion body 42 is pressed against the buried pipe 70, the friction support force acting between the buried pipe 70 and the expansion body 42 causes the buried pipe 70 to be held and fixed to the expansion body 42, that is, the propulsion shaft body 30. Become. Since the expansion body 42 comes into elastic contact with the buried pipe 70, there is no fear that the buried pipe 70 will be damaged or locally deformed. When the pressurized air filled in the expansion body 42 is released, the expansion body 42 contracts inward, so that the holding and fixing to the buried pipe 70 is released.

As shown in FIG. 4, the support member 44 of the holding and fixing means 40
consists of a cylindrical plate 43 to which an expander 42 is attached and an end plate 48 that supports the cylindrical cotton plate 43 on the propulsion shaft body 30. A space 47 is formed therethrough. Laser surveying refers to irradiating a laser beam toward the excavator 10 from a laser measurement device installed in a shaft or the like at the end of the buried pipe 70, and using a target (not shown) provided on the excavator 10. The reflected laser beam is detected again by the laser positioning device to measure the position of the excavator 10, that is, the curvature and inclination of the buried hole. The target space 45 is for securing the laser optical path. The cable piping insertion space 47 is provided with a power cable, hydraulic piping, etc. for supplying power and hydraulic pressure to the drive motor 26, direction adjustment jack 15, and other mechanical parts of the excavator 10.

The holding and fixing means 40 is a propulsion shaft body 30 that is added to the front and back.
The holding and fixing means 40 may be provided for all of the propulsion shaft bodies 30, or may be provided for every plurality of propulsion shaft bodies 30. A portion of the tip of the buried pipe 70 held and fixed to the forwardmost propulsion shaft body 30 is inserted into the inside of the rear cylinder part 16 of the excavator 10. The holding and fixing means 40 disposed on the plurality of propulsion shaft bodies 30 can be installed easily if the plurality of holding and fixing means 40 can be operated or deactivated at the same time, such as by using a common pressure air supply pipe 46. In the above manner, it is easy to release the holding and fixing of the buried pipe 70 and disassemble and remove the propulsion shaft body 30 later.
The propulsion shaft body 30 and the buried pipe 70 are successively added to the rear of the excavator 10. As shown in FIG. 2, a mud feeding pipe 94 connected to a water or mud water supply device is connected to the outer surface of the outer pipe line 34 in the rearmost propulsion shaft body 30a. The inner conduit 32 penetrates the outer conduit 34,
A mud removal pipe 92 is connected to the propulsion shaft body 30, which extends to the outside and is connected to a device for separating earth and sand and muddy water. A main push jack 5 is connected to the rear end of the propulsion shaft body 30a via a shaft 52.
0 is deployed.

The main pusher jack 50 is supported by the fixed wall 6o of the shaft, expands and contracts forward, and provides propulsive force to the propulsion shaft body 30a.

When the propulsion shaft body 30a propels and moves, the mud feeding pipe 94 and the mud draining pipe 92 also need to move, so both pipes 92.
94 is preferably made of a flexible hose or the like so as to be expandable and deformable. After propelling the rearmost propulsion shaft 30a a certain distance, the propulsion shaft 301 is moved back to its original position by retracting the original pusher jack 50. Return it to the position shown in FIG.
Insert another new propulsion shaft body 30, and then insert the propulsion shaft body 3 one after another.
Try adding 0's. In this way, the mud feeding pipe 94 and the mud draining pipe 92 can be connected to the rearmost propulsion shaft body 30.
Propulsion of the propulsion shaft body 30 and additional connection work can be performed while it is attached to the shaft a.

A method of propelling and burying the buried pipe 7o using the above-mentioned device will be explained. First, the excavator 10 is horizontally propelled while excavating the ground from the side wall of the shaft that serves as the starting shaft. The buried pipe 7o is individually placed over the propulsion shaft 30 and fixed to the propulsion shaft 30 by the holding and fixing means 4o. The propulsion shaft body 30 to which the buried pipe 7o is held and fixed is connected to the rear part of the excavator 10, and the internal and external pipes 32 and 34 of the propulsion shaft body 30 are
It is connected to the excavator 10 and the rearmost propulsion shaft body 30a, so that water or muddy water can be supplied to the excavator 10, and excavated earth and sand can be discharged backward together with the muddy water.

The excavation machine 10, the propulsion shaft 30, and the buried pipe 70 are integrated by excavating the ground with the excavation 1ialo to form a burial hole, and applying a propulsive force to the rearmost propulsion shaft 30a with the push jack 50. and propelled into the buried hole.

When excavating the ground, the intake chamber 14 of the excavator 10 is filled with water or muddy water and a constant pressure is applied to the ground in front, so the ground does not collapse or ground water spouts out. . The excavated earth and sand are sequentially discharged to the rear along with muddy water.

Once one set of propulsion shaft 30 and buried pipe 70 is propelled into the ground, the excavator 10 adds another new propulsion shaft 30 and buried pipe 70 and repeats the same process as described above.
When reaching the target shaft, the excavator 10 is disassembled and removed from the rear propulsion shaft body 30. Once the buried pipe 70 is buried along the entire length of the buried hole, the holding and fixing of the buried pipe 70 by the propulsion shaft body 30 is released, and only the propulsion shaft body 30 is disassembled and removed while leaving the buried pipe 70 in the buried hole. . In this way, the propulsion and burial construction of the buried pipe is completed.

〔Effect of the invention〕

According to the buried pipe propulsion method according to the present invention described above, the buried pipe can be held and fixed to the propulsion shaft body, and at the same time, it is possible to prevent excessive pressure or stress from being locally generated on the buried pipe. This means that a so-called mud water pressurization propulsion method can be applied, in which water or mud is supplied to the excavator and excavation is carried out while applying a constant pressure to the ground.

In other words, the propulsion shaft body is constructed of a double pipe, and the two layers of pipelines inside and outside of this double pipe are used as mud feeding piping and mud removal piping, so it is necessary to hold and fix the buried pipe to the propulsion shaft body. The functions of the mud feeding piping and mud draining piping can be performed without affecting the structure or arrangement of the means at all. Furthermore, since there is no need to separately install mud feeding piping and mud draining piping, the labor of piping construction can be saved, and there is no need to separately prepare piping parts, so equipment costs and construction costs can be reduced.

As a result, the advantages of the mud pressurization method, such as being able to effectively prevent ground collapse and groundwater gushing out, improving excavation efficiency, and efficiently discharging excavated earth and sand, and the fact that buried pipes The advantage of the method of holding and fixing the pipe to the propulsion shaft is that no excessive pressure or stress is applied to the buried pipe.

Therefore, it is now possible to use pipe materials with poor strength such as PVC pipes, which was extremely difficult with conventional muddy water pressure construction methods, and to carry out continuous propulsion over long distances, which is impossible with conventional construction methods. It is possible to improve the construction efficiency of the propulsion method, improve the corrosion resistance of buried pipes, and significantly reduce construction costs.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the tip of the construction device for carrying out the propulsion method of the present invention, Fig. 2 is a cross-sectional view showing the rear end, and Fig. 3 is an enlarged cross-section of the main part showing the connecting part of the propulsion shaft body. Figure, 4th
The figure is an enlarged sectional view taken in a direction perpendicular to FIG. 1. DESCRIPTION OF SYMBOLS 10... Excavation machine 30... Propulsion shaft body 32... Inner pipe line 34... Outer pipe line 40... Holding and fixing means 50... Original push jack 70... Buried management agent Patent agent Master Takehiko Matsumoto!

Claims (1)

[Claims] 1. While sequentially adding the propulsion shaft and the buried pipe held and fixed on the outside of the propulsion shaft to the rear of the excavation machine, apply propulsive force to the propulsion shaft to move the excavation machine and the buried pipe into the buried hole. In the underground pipe promotion method that is being promoted,
The propulsion shaft body is composed of a double pipe, and among the inner and outer pipes of the double pipe,
A buried pipe characterized in that water or mud is supplied to an excavator through one pipe to pressurize the ground, while earth and sand excavated by the excavator is discharged backward along with muddy water through the other pipe. Propulsion method.