JPH07992B2 - Supporting device for buried pipe in propulsion method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support device for a buried pipe in a propulsion method, and more specifically, when an underground buried pipe such as a sewer is constructed, a buried hole is formed in the ground without excavating the ground. Therefore, in the so-called propulsion method, in which the buried pipes are sequentially promoted and buried in the formed buried holes,
The present invention relates to a support device for holding and fixing an embedded pipe with respect to a propulsion shaft that is connected to a leading conductor that forms an embedded hole.

[0002]

2. Description of the Related Art In the conventional propulsion method, a tube material having mechanical strength or axial load-carrying capacity such as a fume tube or a steel tube is usually used as a buried tube. It was said that tubing materials with poor directional load capacity could not be used. This is because in the conventional propulsion method, a buried pipe is connected to the rear of the front conductor of an auger or a mud digging machine, and a thrust force is applied to the last buried pipe with a push jack installed in the shaft. In addition, it overcomes the friction resistance and excavation resistance of the ground, and promotes the buried pipe row and the lead conductor into the ground. Therefore, a very large force is applied to the end face of the buried pipe row, particularly the tailmost buried pipe, and the pipe material having no durability is locally deformed or damaged.

Therefore, a propulsion shaft body made of steel or the like is added and connected through the center of the buried pipe row behind the front conductor, and a propulsion force is applied to the tail end of the propulsion shaft row with a push jack to lead the lead shaft. A method has been proposed in which the body is propelled, the buried pipe row is connected and fixed behind the front conductor, and the buried pipe row is pulled by the front conductor. In this method, since the excavation resistance of the leading conductor is not transmitted to the buried pipe row, the force applied to the buried pipe row is smaller and the durability required for the pipe material is also smaller than the above method. However, even with this method, the frictional resistance applied to the buried pipe from the ground is transmitted to the leading side of the buried pipe row in sequence, and at the connection point between the leading conductor and the leading buried pipe,
Since all the resistance force is applied, the buried pipe closer to the head in the buried pipe row receives a larger force, and the above-mentioned pipe material having a poor axial load-bearing force cannot be sufficiently dealt with.

Therefore, the present inventors hold and fix the buried pipe on the propulsion shaft body passed through the center of the buried pipe, and determine the propulsive force applied to the buried pipe row and the frictional resistance from the ground for each buried pipe. Alternatively, by inventing a method in which a proper number of buried pipes are dispersed and transmitted between the propulsion shafts, Japanese Patent Application Nos. 1-183271 and 1-240408, A patent application has been filed in Japanese Patent Laid-Open No. 2-289901.

In this method, since the force can be transmitted to the propulsion shaft by being dispersed at a plurality of positions in the buried pipe row, the conventional method of transmitting the force only at the tail or the beginning of the buried pipe row. The force applied to each of the buried pipes can be markedly reduced as compared with. In addition, if the rubber expansion bag provided in the support device is pressed against the inner surface of the embedded pipe and the embedded pipe is supported by the friction supporting force that acts between them, a uniform force is applied to the entire circumference of the embedded pipe. As compared with applying a force to the end of the buried pipe, the buried pipe is less likely to be locally deformed or damaged. As a result, the propulsion method can be applied even to a pipe material having a poor axial load resistance such as the above-mentioned PVC pipe.

[0006]

However, in the method of holding and fixing the embedded pipe to the propulsion shaft body as in the above-mentioned prior art, between the supporting device provided on the propulsion shaft body and the inner surface of the embedded pipe body. When the embedded pipes are supported by the friction supporting force, the force that can be transmitted between the individual embedded pipes and the propulsion shaft is not so large.

Therefore, in the case where a method of supporting a plurality of embedded pipes on the propulsion shaft body is adopted, when the number of embedded pipes supported on the propulsion shaft body becomes too large, one embedded pipe and the propulsion shaft body are provided. The force to be transmitted between the pipes becomes large, and the friction support force between the supporting device of the propulsion shaft and the buried pipe cannot handle it.Slippage occurs between the buried pipe and the support device, and the buried pipe can be propelled. The problem of disappearing occurs.

However, if the supporting devices are attached to all the propulsion shafts and all the buried pipes are supported by the propulsion shafts inside the supporting pipes, the equipment cost of the supporting device is high and the supporting devices are embedded in the supporting device. It is very troublesome to support the pipe and disconnect the support device and the buried pipe after construction. Moreover, even if all the buried pipes are supported by the propulsion shafts inside, if the ground frictional resistance is extremely large, it is not possible to deal with it only by the friction supporting force of the supporting device and the buried pipes. There are cases.

In any case, it is necessary to further increase the frictional support force that can be transmitted between the support device attached to one propulsion shaft and the inner surface of the buried pipe. Next, in the conventional supporting device, a plurality of donut-shaped expansion bags are arranged in the axial direction of the propulsion shaft, or a rod-shaped expansion bag parallel to the axial direction of the propulsion shaft is arranged in the circumferential direction of the propulsion shaft. It was possible to increase the friction support force by increasing the contact area between the buried pipe and the support device by arranging multiple tubes in the same space, but when the number of expansion bags increases, pressure air etc. is sent to each expansion bag. The piping structure and the mounting structure of the expansion bag are complicated, the equipment cost increases, and the handling is also troublesome. Especially, the space between the propulsion shaft and the buried pipe is quite narrow, and in this space,
The space required for these propulsion methods is provided because a surveying space for surveying the position of the lead conductor is opened, and cables for supplying power to the lead conductor and controlling the operation of the lead conductor are arranged. It is not preferable that the support device, the expansion bag, or the piping to the expansion bag occupy the space. Further, when constructing a small-diameter embedded pipe, the gap between the propulsion shaft and the embedded pipe may be narrow, and installation may not be possible with a conventional supporting device.

Further, if a large number of donut-shaped expansion bags are arranged in the axial direction of the propulsion shaft in order to increase the frictional supporting force, there is a drawback that it is difficult to supply pressurized air to the expansion bag inside. Moreover, since the expansion rate varies depending on each expansion bag, it is very difficult to evenly press many expansion bags against the buried pipe, so only some of the expansion bags can exert sufficient frictional supporting force. As a result, the frictional supporting force does not improve so much in the supporting device as a whole. Further, when the rod-shaped expansion bag is arranged along the axial direction of the propulsion shaft, the center part of the expansion bag that can be freely deformed expands more than the positions near the mounting parts at both ends, so that it is substantially Since the inner surface of the buried pipe is frictionally supported only by the central portion of the expansion bag, the friction supporting force is not so high as compared with the size of the expansion bag.

Therefore, an object of the present invention is to increase the friction supporting force that can be transmitted between the embedded pipe and the embedded pipe in the support device for holding and fixing the embedded pipe to the propulsion shaft as described above, and also to the support device and its attendants. It is an object of the present invention to provide a support device for a buried pipe in a propulsion method in which the equipment used is as compact as possible and saves space.

[0012]

In order to solve the above-mentioned problems, a buried pipe supporting device in a propulsion method according to the present invention is
A support device for holding and fixing an embedded pipe to a propulsion shaft that is connected to the rear of the front conductor and transmits a propulsive force to the front conductor. It is provided with an expansion tube that expands to the outer peripheral side when supplied, and an outer cover that covers the outer circumference of the expansion tube.

The expansion tube is made of a material that is elastically deformable, such as rubber or a flexible synthetic resin, and can be expanded by supplying a pressure medium such as air, water, or oil to the inside of the expansion tube. It is formed into a shape. The material, thickness, and outer shape of the expansion tube are set in consideration of conditions such as the diameter of the buried tube and the amount of frictional supporting force to be transmitted. The cross-sectional shape of the expansion tube is preferably such that it can be greatly deformed in the thickness direction when the fluid pressure is supplied to the inside and when it is not supplied. Specifically, when the fluid pressure is not supplied to the expansion tube, it is preferably a flat elliptical shape or an elliptical shape, and when the fluid pressure is supplied, the expansion tube expands in the minor axis direction and becomes close to a circular shape.

The expansion tube surrounds the outer periphery of the propulsion shaft and is arranged in a spirally wound state at a position where it can contact the inner surface of the buried pipe. If the diameter of the buried pipe is small, it is possible to wind the expansion tube directly on the outer peripheral surface of the propulsion shaft, but normally it will be separated from the outer peripheral surface of the propulsion shaft by a certain distance. It is preferable to attach a concentric support tube and wind the expansion tube around the support tube. The space between the support cylinder and the propulsion shaft is used as the above-mentioned survey space or a passage space for various piping cables.

The expansion tubes may be wound so as to be in close contact with each other so that adjacent expansion tubes come into contact with each other, or may be wound with a space therebetween. It is preferable to provide a regulating member that can come into contact with the side surface of the expansion tube so that the wound expansion tube does not move in the axial direction of the propulsion shaft. The restricting member may be in contact with only both end side surfaces of the entire expansion tube. If a restricting member having a spiral shape is provided in accordance with the spiral shape of the expansion tube, each winding circle of the expansion tube The movement can be reliably regulated for each lap. Further, the lower surface of the expansion tube may be fixed to the support cylinder. Further, by providing the expansion tube so as to be movable to some extent, it may be possible to perform the action of adjusting the contact with the inner peripheral surface of the buried tube or the deviation of the frictional support force.

The expansion tube may be provided at any one end,
A pressure medium supply / discharge port for supplying and discharging the pressure medium is provided. Various valve devices used for connecting ordinary pressure pipes and hoses are attached to the supply / discharge ports. As for the expansion tube, one continuous expansion tube may be wound over the entire length of one propulsion shaft, or the total length of the propulsion shaft may be divided into a plurality of parts.
It may be wound with a plurality of expansion tubes so as to cover the entire length of the propulsion shaft. In this case, separate fluid pipes may be connected to the pressure medium supply / discharge ports of the respective expansion tubes, or the pressure medium supply / discharge ports of the respective expansion tubes may be connected in sequence so that a plurality of expansion tubes are provided with a single fluid pipe. The fluid pressure may be supplied from the fluid pipe.

Furthermore, if a plurality of expansion tubes are arranged side by side and are spirally wound at the same time, the plurality of expansion tubes are wound in a cylindrical shape surrounding the outer periphery of the propulsion shaft while being alternately arranged. To be turned. This is a so-called double spiral or double spiral structure. In this case, the pressure medium supply / discharge ports of the respective expansion tubes can be arranged side by side on the end surface of the wound expansion tube, which facilitates connection to the fluid pipe. Also, if the pressure medium supply to each expansion tube can be controlled independently, even if one expansion tube is damaged, it does not affect the other expansion tubes, so that it does not hinder the support of the buried pipe, It is possible to supply the fluid pressure only to an appropriate number of expansion tubes in accordance with the proper friction supporting force and the durability of the buried pipe. Such an operation can be easily realized by appropriately designing the arrangement structure of the fluid piping and the piping design such as the pressure control valve.

The expansion tube may be wound over the entire length in the axial direction of the propulsion shaft, may be wound only over a certain length near the center, or around the front and rear ends. It may be wound around a plurality of places intermittently. The outer circumference of the expansion tube is covered with an outer cover. The outer cover can be expanded, contracted, or deformed in response to expansion and contraction deformation of the expansion tube, and is also interposed between the inner surface of the embedded tube and the expansion tube to prevent the expansion tube from being scratched or worn, and to be embedded. A material that can increase the coefficient of friction with respect to the pipe is used. Specifically, an elastic material made of rubber or the like similar to the expansion tube is preferable. Further, the outer cover itself may not be elastically deformable, but may be attached so that it can be moved or deformed as the expansion tube expands and contracts. Specifically, abrasion-resistant knitted fabric, synthetic resin sheet, or the like can be used.

The outer cover may be attached and fixed to the expansion tube, but it is better to be directly fixed to the propulsion shaft through a support cylinder or the like to which the expansion sheet is attached. This is because it is possible to prevent the axial force applied to the outer cover due to friction with the buried pipe from being transmitted to the expansion tube. If the outer surface of the outer cover that contacts the buried pipe has fine irregularities such as protrusions and grooves, or if surface treatment is performed to increase the coefficient of friction, friction support for the buried pipe will be obtained. You can increase your strength. On the contrary, if the contact surface between the jacket cover and the expansion tube is made slippery, it is difficult for the jacket cover to apply an axial force to the expansion tube.

The outer cover may be mounted in a cylindrical shape by covering the entire expansion tube with a single outer cover, but a plurality of strip-shaped outer covers along the axial direction of the propulsion shaft may be used. It is easier to deform the expansion tube due to the expansion and contraction and to reliably transmit the friction supporting force if the expansion tubes are mounted in a state of being arranged on the circumference. Even if there is a certain amount of gap between the divided outer covers, the entire frictional supporting force can be sufficiently secured.

The above-mentioned embedded pipe support device can be attached to a propulsion shaft having any conventional structure. The propulsion shaft body is made of a steel pipe or the like, and has a screw conveyor for discharging soil therein, a muddy water supply and discharge passage, and a rotary shaft for rotationally driving the auger of the leading conductor. If the support device is detachably attached to the propulsion shaft body by bolt fastening or the like, the support device can be attached and used only on the necessary propulsion shaft body.

Regarding the structure of the lead conductor and the specific method of the propulsion method, the usual propulsion method can be applied as it is, and examples thereof include an auger excavation method, a mud pressure method, a consolidation method, and the like. The structure of the mechanical device provided in the leading conductor is different. The buried pipe supported by the supporting device of the present invention can exert a great effect when used in a pipe material having a relatively poor axial load resistance, such as the above-mentioned PVC pipe or FRPM pipe, Even if a fume pipe or a steel pipe has a relatively small wall thickness, a preferable effect can be obtained.

[0023]

The slender expansion tube is spirally wound and arranged, and a fluid pressure is supplied to the expansion tube to expand the expansion tube to the outer peripheral side. Since it comes into contact with the inner surface of the buried pipe via the pressure, the pressure can be uniformly applied to the inner surface of the buried pipe over the entire circumference. That is, the frictional force can be transmitted through the entire spiral contact line between the expansion tube and the buried tube, and the frictional supporting force can be increased.

Compared to the conventional structure in which a large number of donut-shaped expansion bags are arranged, a large number of donut-shaped expansion bags are replaced by a single expansion tube, so the pressure medium supply / discharge port is
It only needs to be installed at the end of the expansion tube,
The installation of pressure medium supply piping can be simplified and the number of parts can be greatly reduced. Moreover, it is extremely difficult to evenly inflate and shrink a large number of independent donut-shaped inflatable bags,
With a single expansion tube, it is possible to expand and contract substantially evenly on each spiral winding circumference, so pressure is applied evenly to the entire inner surface of the buried pipe to increase the substantial contact area. A large friction supporting force can be applied.

Next, when the expansion tube wound in a spiral shape is in direct contact with the buried tube, the outer peripheral end of the expansion tube comes into linear contact, but the expansion tube is not If the buried pipe is contacted through the covered pipe, the outer cover is brought into full contact with the inner surface of the buried pipe, and the frictional supporting force for the buried pipe is significantly increased. In particular, if the jacket cover is directly attached to the propulsion shaft through the main body portion of the supporting device instead of the expansion tube, the transmission of the axial force between the embedded pipe and the propulsion shaft is prevented by the jacket. Since it is performed through the cover, no axial force is applied to the expansion tube, so the expansion tube is not deformed or moved in the axial direction, and the expansion force of the expansion tube is Since it is effectively used only for pressurization to, that is, generation of the friction supporting force, the friction supporting force of the buried pipe is further increased. This is because if the expansion tube is only spirally wound, the individual winding circumferential portions may move in the axial direction, so that the jacket cover allows the expansion tube to move in the axial direction. It is very effective not to apply the force of.

The outer cover also has an effect of preventing the expansion tube from being scratched or worn. For the outer cover, a material having excellent durability and abrasion resistance is used. By using a material with excellent expansion and contraction,
It is possible to exert each performance more effectively.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a use state of the supporting device according to the present invention. A shaft V is excavated in the ground E, and a buried hole H is horizontally excavated from the side wall of the shaft V. The front conductor 1 having the auger 10 at its tip is connected to the rear end of the propulsion shaft body 2 made of a steel pipe or the like in order to be added. Inside the propulsion shaft body 2, a screw conveyor 11 for rotationally driving the auger 10 and discharging the soil is provided. The rear end of the propulsion shaft body 2 is adapted to receive a thrust from an original push jack (not shown) installed in the vertical shaft V.

The buried pipe 3 made of a vinyl chloride pipe or the like is the lead conductor 1
Is sequentially added to the rear of the so as to surround the outer periphery of the propulsion shaft body 2. The buried pipe 3 may be fixed to the lead conductor 1, but it is not necessary to transmit the propulsive force from the lead conductor 1, and therefore it is sufficient to connect the buried pipe 3 to the lead conductor 1 so as not to separate from the lead conductor 1. A support device 4 is attached to the propulsion shaft 2. The outer periphery of the support device 4 abuts on the inner surface of the embedded pipe 3, and the embedded pipe 3 is attached and fixed to the support device 4, that is, the propulsion shaft body 2 by the friction supporting force generated between the support device 4 and the inner surface of the embedded pipe 3. To do.
Therefore, the thrust force applied to the propulsion shaft body 2 from the original push jack is transmitted to the embedded pipe 3 via the support device 4, and the embedded pipe 3 is propelled against the frictional resistance applied to the embedded pipe 3 from the ground E. Let

3 and 4 show the overall structure of the supporting device 4. A supporting cylinder 50 having a cylindrical shape concentric with the propulsion shaft 2 is attached to the propulsion shaft 2 with interposing disk-shaped both-end support plates 54, 54. The support cylinder 50 is provided up to almost both ends of the propulsion shaft 2. As shown in FIG. 4, the both end support plates 54, 54 are provided with an opening 56 serving as an irradiation path of a laser beam for surveying, and a through path 58 serving as a path for a power cable to the leading conductor 1 and the like. There is.

An expansion tube 60 is spirally wound around the outer surface of the support cylinder 50. Expansion tube 60
Is a long and thin rubber tubular body, and is provided with valve devices 62, 62 at both ends serving as supply / discharge ports for the pressure medium. A pipe 70 is connected to the valve devices 62, 62, and the pipe 70 is connected to a shaft V or a pressure medium source installed on the surface of the earth.

The outer circumference of the expansion tube 60 is covered with an outer cover 80 made of a strip-shaped rubber sheet or the like. Figure 5
As shown in detail in FIG.
The bolts b are fastened to the flange portions 54 provided at both ends of the support cylinder 50. As shown in FIG. 4, the outer cover 8
Reference numeral 0 covers the outer circumference of the expansion tube 60 by dividing it into a plurality of pieces (six pieces in the figure) in the circumferential direction.

The use of the supporting device 4 having the above structure will be described. As shown in FIGS. 3 and 5, when the pressure medium is not supplied to the expansion tube 60, the expansion tube 60 has a flat oval shape,
The outer cover 80 is also flat. The outer diameter of the outer cover 80 or the outer diameter of the entire supporting device 4 is set to be slightly smaller than the inner diameter of the buried pipe 3. Therefore, the propulsion shaft body 2 to which the supporting device 4 is attached can be easily inserted into the embedded pipe 3.

As shown in FIGS. 1 and 6, when a pressure medium is supplied to the expansion tube 60 to expand the expansion tube 60, the inner peripheral side of the expansion tube 60 is restricted by the support cylinder 50. The entire expansion tube 60 expands and moves to the outer peripheral side. When the expansion tube 60 expands to the outer peripheral side, the outer cover 80 also deforms so as to expand to the outer peripheral side, and the outer cover 80 is pressed against the inner surface of the buried pipe 3. As a result, a frictional supporting force is generated between the outer cover 80 and the inner surface of the embedded pipe 3, so that the embedded pipe 3, the support device 4, and the propulsion shaft 2 are connected and fixed.

In this way, the integrated structure of the propulsion shaft 2 and the buried pipe 3 is arranged behind the front conductor 1 as shown in FIG. 2, and the propulsion shaft 2 is connected to the front conductor 1. Fix it. The propulsion shafts 2 are sequentially added rearward and connected and fixed. The embedded pipes 3 are also sequentially joined by fitting and adhering with a sleeve. When a thrust force is applied to the rearmost end of the propulsion shaft body 2 by a pushing jack or the like, the propulsion shaft body 2 and the front conductor 1 are propelled, and the embedded pipe 3 supported by the propulsion shaft body 2 is also propelled. In addition, in FIG. 2, all the embedded pipes 3 are supported by the supporting device 4 inside thereof, that is, the propulsion shaft body 2.
Considering the magnitude of the frictional resistance force from the ground E and the durability of the embedded pipe 3, the propelling shaft 2 can be propelled even if only some of the embedded pipes 3 are supported by the propulsion shaft 2. It is not necessary to attach the supporting device 4 to the propulsion shaft body 2 that does not support the embedded pipe 3.

As described above, the buried pipe 3 is propelled into the ground E together with the front conductor 1 and the propulsion shaft body 2, and the buried hole H is formed.
Simultaneously with the formation, the buried pipe 3 is laid in the buried hole H. After the buried pipe 3 is laid from the starting shaft V to the target shaft, if the pressure medium supplied to the expansion tube 60 of the supporting device 4 is discharged, the expansion tube 60 contracts,
The fixed support of the buried pipe 3 and the support device 4 is released. When the support device 4 and the propulsion shaft body 2 are pulled out from the buried pipe 3, only the buried pipe 3 remains in the buried hole H of the ground E, and the construction of the buried pipe 3 is completed.

[0036]

As described above, according to the buried pipe supporting device in the propulsion method of the present invention, the expansion device spirally wound by the supporting device attached to the propulsion shaft body is expanded. , The frictional supporting force that acts between the outer cover that covers the outer circumference of the expansion tube and the embedded pipe supports and fixes the embedded pipe to the propulsion shaft, thereby providing a strong frictional supporting force between the embedded pipe and the supporting device. Can be operated.

As a result, of the embedded pipes that form a long embedded pipe array, even if only some of the embedded pipes are supported by the propulsion shaft with the support device, the entire embedded pipe array is reliably supported. The number of supporting devices required can be reduced, the number of man-hours for supporting or releasing the embedded pipe on the supporting device can be reduced, and the facility cost and the working time can be shortened. .

Further, it becomes possible to securely support and fix the buried pipe even in the case of soil soil having a very large frictional resistance, and the propulsion method for supporting the buried pipe on the propulsion shaft can be applied. Ground conditions will be expanded. The expansion tube arranged in a spiral winding is attached only by supporting both ends thereof, and the pressure medium can be supplied to the entire expansion tube from the supply / discharge port provided in a part thereof. The pressure medium supply mechanism and the expansion tube mounting structure are extremely simple, and the overall structure of the supporting device can be simplified or downsized. As a result, even when constructing a small-diameter buried pipe, it becomes possible to mount the support device inside the buried pipe, and the range of the diameter of the buried pipe to which such a propulsion method can be applied is expanded.

[Brief description of drawings]

FIG. 1 is a sectional view showing a mounting state of a buried pipe by a supporting device showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the construction state of the propulsion method.

FIG. 3 is a sectional view showing a state in which the support of the buried pipe by the support device is released.

FIG. 4 is a sectional view in a direction orthogonal to FIG.

FIG. 5 is an enlarged sectional view showing a detailed structure of an expansion tube portion.

FIG. 6 is an enlarged sectional view showing a state in which a buried pipe is supported.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leader conductor 2 Propulsion shaft body 3 Buried pipe 4 Support device 50 Support cylinder 60 Expansion tube 70 Piping 80 Envelope cover

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Koji Nishida 9-507 Toyoharacho, Ibaraki City, Osaka Prefecture

Claims (1)

[Claims] 1. A support device connected to the rear of a lead conductor for holding and fixing an embedded pipe on a propulsion shaft for transmitting a propulsive force to the lead conductor, the support device surrounding the outer periphery of the propulsion shaft and being arranged in a spiral shape. A support device for a buried pipe in a propulsion method, comprising: an expansion tube that expands toward the outer peripheral side by supplying a pressure medium and an outer cover that covers the outer periphery of the expansion tube.