JP6216017B2 - Removal method for long underground objects - Google Patents

Description

  The present invention relates to an apparatus and method for removing a long underground object such as a power cable.

  In recent years, the number of underground long objects such as power cables that have become unnecessary due to the end of their service life has been rapidly increasing. It is desirable that such long underground objects be quickly removed from the viewpoint of maintenance costs, recycling, and effective use of underground space.

  By the way, power cables, communication cables, gas pipes, water pipes, etc. are buried in long underground materials, either directly called the buried method or called the pipe buried method. Different removal methods are implemented depending on the method.

  In the direct burying method, a buried object such as a power cable is arranged in the trough and directly buried in the ground. On the other hand, in the pipe burying method, a long underground object such as a power cable is accommodated in a pipe laid between manholes.

  When removing underground long objects buried by the direct embedding method, a method of digging up the soil above the buried underground long objects from the ground surface is employed.

  On the other hand, when removing an underground long object buried in the pipe burial method, a method of pulling out the long object to be removed accommodated in the pipe from the inside of the manhole is employed. However, due to the fact that, for example, the ground improvement agent penetrates into the pipe over the years, the underground object to be removed is stuck in the pipe and cannot be easily pulled out from the pipe. In many cases. Therefore, conventionally, methods for removing the underground cable fixed in the pipe in this way are described in Patent Documents 1 and 2. In short, the methods of Patent Documents 1 and 2 use an excavation pipe that excavates in the extending direction of the underground long object while interpolating the underground long object to be removed, and By separating from the surrounding objects, the long underground objects are removed.

JP 2001-224112 A Japanese Patent No. 4190380

  By the way, long underground objects buried by the direct burying method must be removed by digging up the soil on the upper side, so that not only the removal work becomes large, but also the ground above the underground long objects. When there are structures such as buildings on the surface, it is virtually impossible to dig up and remove. Even if there are no structures on the ground surface, it is difficult to remove without damaging them if there are other buried objects in the vicinity of the long underground objects to be removed. there were.

  In Patent Documents 1 and 2, water or the like is poured into the excavation pipe. For example, in patent document 2, the water poured into the insertion tube (flexible tube) is blown out from the tip of the peeling head and flows out to the working side.

  However, the insertion tube (flexible tube) has a structure in which a cable is fitted, and the gap between the inner surface of the insertion tube and the cable is only a few millimeters (4 mm in Patent Document 2). There is a possibility that the phenomenon that the pressurized water etc. does not reach the tip may occur.

  Regarding the reflux water, Patent Document 2 describes that it passes between the flexible pipe (insertion pipe) and the pipe line (gap), but this gap is also 14 mm, and the eyes of the excavated object There is a risk that the clogged water may not return to the work area. Saying that the reflux water does not return to the work side means that the excavated material cannot be carried out to the outside. Therefore, as a countermeasure, a method of pulling back the insertion tube and removing the excavated material clogged between the inner surface of the conduit and the cable can be considered. However, if this is done, continuous work cannot be performed, and as a result, the object to be removed is removed. It takes a long time to do.

  The present invention has been made in consideration of the above points, and can create a flow of water suitable for removal of long underground objects, and can easily remove long underground objects. A scale removing device is provided. In addition, the present invention can be used when there is a structure such as a building on the ground surface above a long underground object buried by the direct embedding method, or when there are other buried objects near the underground long object. Provided is an underground long object removal method capable of removing an underground long object even if it exists.

One aspect of the method for removing underground long objects of the present invention is:
It is a method for removing long underground objects buried in a pipe burial method,
Installing a digging pipe so as to interpolate the long underground object, and installing a propulsion device that applies rotational force and pushing force to the digging pipe; and
Installing a water supply unit for supplying water to the excavation pipe;
Including
An inner tube into which the underground long object is inserted; and an outer tube disposed on the outer peripheral side of the inner tube;
Using the digging pipe provided with a digging blade at the tip of the digging direction of either the inner pipe or the outer pipe, the outer surface of the inner pipe and the outer surface are supplied by supplying water at a predetermined water pressure from the water supply unit. Water is allowed to flow toward the tip of the digging pipe through the gap between the inner surface of the outer pipe, and the outer surface of the inner pipe is narrower than the other parts with the diameter of the tip part in the digging direction being larger than the rear end part. By digging the digging pipe in the extending direction of the underground long object by rotating the pipe provided with the digging blade while spouting the water from the tip part in the digging direction of the gap, The excavated water is excavated in cooperation with the ejected water and the excavating blade, and the water mixed with the excavated material passes through the gap between the inner surface of the inner pipe and the outer surface of the underground long object. The method further includes a step of refluxing in the direction of the propulsion device.

  According to the present invention, since the excavation pipe has a multi-pipe structure, a flow of water suitable for removal of the underground long object can be created so that the underground long object can be easily removed. Become. In addition, since the start pit and the arrival pit are excavated in the underground long material burial path and digging is carried out using the multi-tube structure digging pipe, the ground above the underground long material buried by the direct burying method is used. Even when there is a structure such as a building on the surface, or when another buried object is present at a position close to the underground long object, the underground long object can be removed.

The figure which shows schematic structure of the removal apparatus which concerns on embodiment Sectional drawing which shows the detailed structure of the digging pipe of this Embodiment Development of the inner surface of the rod Cross section showing the flow of water in the digging pipe

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a long underground removal device (hereinafter simply referred to as a removal device) according to an embodiment of the present invention. Embodiment demonstrates the case where the removal apparatus of this invention is applied to removal of the power cable embed | buried by the direct burying system.

  The removal device has a digging pipe 100 that digs in the extending direction of the power cable 1 while interpolating the power cable 1 as a long underground object to be removed, and a propulsion that provides the digging pipe 100 with a driving force for digging. Pull-out equipped with a machine 10, a water supply unit 20 for supplying water to the excavation pipe 100, a drainage unit 30 for draining water mixed with the excavated material returning from the excavation pipe 100, and a ball roller that sandwiches and pulls the power cable 1 Device 40.

  When using the removal device of the present embodiment, first, the start pit 2 and the arrival pit 3 are excavated. The start pit 2 and the arrival pit 3 may be excavated from the ground surface using a backhoe or the like. What is necessary is just to select the distance between the start pit 2 and the arrival pit 3 suitably according to the extent to which the power cable 1 is fixed in the ground, the position where the start pit 2 and the arrival mine 3 can be excavated, and the like. Actually, the distance between the start pit 2 and the arrival pit 3 is about 200 m. In general, since the power cable 1 is buried at a depth of about 1.2 m from the ground surface, the depth of the start pit 2 and the arrival pit 3 is about 1.5 m. Further, the width and depth of the start pit 2 and the arrival pit 3 are about 3 m.

  Next, the power cable 1 is cut in the start pit 2 and the arrival pit 3. Next, in the start pit 2, the excavation pipe 100 is installed so as to insert the power cable 1, and the propulsion unit 10 is installed so as to be connected to the excavation pipe 100. The excavation pipe 100 is lengthened by sequentially adding rods as the excavation progresses. The method of adding the rod is the same as that of a general boring machine. In the access shaft 3, the power cable 1 is held between the two ball rollers of the drawing device 40. The drawing device 40 pulls the power cable 1 sandwiched between two ball rollers in the digging direction while the digging pipe 100 is digging. This tension is, for example, about 1 ton.

  FIG. 2 is a cross-sectional view showing a detailed configuration of the excavation pipe 100 of the present embodiment.

  The digging pipe 100 has a double pipe structure including an inner pipe 110 and an outer pipe 120. Here, the inner tube 110 and the outer tube 120 are made of iron, but the material is not limited.

  The inner tube 110 includes a bit part 111, a rod 112, and a rod coupling 113. These parts are connected to each other by screwing. A carbide tip 111a is attached to the bit portion 111 connected to the tip in the digging direction. The cemented carbide chip 111 a is brazed to the front surface and the side surface of the tip portion of the bit portion 111. However, the structure of the excavation blade in the bit part 111 is not restricted to this. The plurality of rods 112 are connected via a rod coupling 113. The inner diameter of the rod 112 and the rod coupling 113 is set to be approximately 10 mm larger than the outer diameter of the power cable 1 to be removed, so that when the power cable 1 is inserted, the rod 112 and the rod A gap of about 5 mm is generated between the inner surface of the coupling 113 and the outer surface of the power cable 1.

  A plurality of guide rollers 114 are provided on the outer surface of the rod 112 of the inner tube 110. Thereby, the inner tube 110 is supported by the guide roller 114 so as to be rotatable with respect to the outer tube 120 while the distance between the outer surface of the inner tube 110 and the inner surface of the outer tube 120 is kept constant. . In FIG. 2, the guide roller 114 is provided on one rod 112, but the guide roller 114 is provided on each rod 112. A bearing or the like may be provided instead of the guide roller 114. In short, a coupling member for coupling the inner tube 110 and the outer tube 120 so that the inner tube 110 and the outer tube 120 have the same core and the inner tube 110 is rotatable with respect to the outer tube 120. What is necessary is just to provide between the inner tube 110 and the outer tube 120.

  The bit part 111 is configured to have a larger diameter than the rod 112. As a result, the gap between the inner tube 110 and the outer tube 120 (specifically, the gap between the outer surface of the inner tube 110 and the inner surface of the outer tube 120) is the tip of the inner tube 110 (on the side of the excavation direction). The bit portion 111 is narrower than the gap at the position of the rod 112. Further, a tapered surface 111b is formed on the inner surface of the bit portion 111, and the inner diameter of the bit portion 111 is a funnel shape that gradually increases in diameter toward the tip side on the digging direction side at the position of the tapered surface 111b. It has become.

  Further, the inner pipe 110 protrudes in the digging direction from the outer pipe 120. Specifically, the tip of the bit portion 111 protrudes about 5 mm from the tip of the outer tube 120.

  Further, a spiral groove is formed on the inner surface of the inner tube 110. FIG. 3 is a development view of the inner surface of the rod 112 showing the state. A spiral groove 112 a as shown in FIG. 3 is formed on the inner surface of the rod 112.

  Next, the operation of the present embodiment will be described.

  First, the start pit 2 and the arrival pit 3 are excavated as described above, the power cable 1 is cut in the start pit 2 and the arrival pit 3, and the digging pipe is inserted in the start pit 2 so that the power cable 1 is inserted. 100 and the propulsion unit 10 are installed so as to be connected to the excavation pipe 100. Further, the power cable 1 is sandwiched between the two ball rollers of the drawing device 40 in the arrival shaft 3.

  When such preparation is completed, excavation by the excavation pipe 100 and the propulsion unit 10 is performed while pulling the power cable 1 by the drawing device 40. The digging is performed by pressing the inner pipe 110 and the outer pipe 120 in the digging direction while the propulsion device 10 rotates the inner pipe 110.

  In addition, at the time of excavation, water having a predetermined water pressure by the water supply unit 20 is supplied to the gap between the outer surface of the inner pipe 110 and the inner surface of the outer pipe 120 (not shown). Supplied through. In this way, the water supplied to the gap between the outer surface of the inner tube 110 and the inner surface of the outer tube 120 is ejected from the tip of the excavation tube 100.

  FIG. 4 is a cross-sectional view showing the flow of water in the excavation pipe 100. The supplied water F <b> 0 that flows toward the tip side (digging direction side) of the digging pipe 100 through the gap between the outer surface of the inner pipe 110 and the inner surface of the outer pipe 120 is supplied from the tip of the digging pipe 100. Erupts. The water F1 ejected from the tip of the excavation pipe 100 excavates excavated items such as earth and sand in cooperation with the carbide tip 111a. Then, the reflux water F2 mixed with the excavated material returns to the propulsion device 10 (see FIG. 1) through the gap between the inner surface of the inner pipe 110 and the outer surface of the power cable 1. The reflux water F2 mixed with the excavated material is sent to the drainage section 30 (see FIG. 1) through the drainage path (not shown) of the propulsion device 10.

  Thus, in the present embodiment, the excavation pipe 100 has a double pipe structure, and the jet water F1 is jetted through the gap between the inner pipe 110 and the outer pipe 120, and the reflux water F2 is connected to the inner pipe 110. By passing through the gap with the power cable 1, a series of operations such as draining the recirculated water F2 mixed with the excavated material while cutting the excavated material with the force of the jet water F1 and scraping with the tip blade is continued. The flow of water suitable for removal of the power cable 1 can be created.

  In other words, the conventional single-pipe structure drill pipe has a structure in which the jet water and the reflux water containing the drilled material are recirculated in the same pipe, so the water injection is actually stopped after the jet cutting. However, it is necessary to remove the excavated material backward (rear end side) with the pressure of the accumulated water at the tip. Therefore, in the excavation pipe having a single pipe structure, since the injection is stopped, the excavation object cannot be removed using the reflux of water, and the excavation object is easily clogged in the excavation pipe. When the excavated material is clogged in the excavated pipe, it is necessary to improve the clogging by pouring water into the excavated pipe, and the work time is increased accordingly. Such a problem can be solved by the double tube structure of the present embodiment.

  In the double-pipe structure of the present embodiment, the jet water F1 passes through a dedicated flow path into which excavated material does not flow, and therefore reliably reaches the tip through the flow path where clogging does not occur. On the other hand, the reflux water F2 returns to the rear by the water pressure of the jet water F1 through a flow path different from the water injection F0.

  Here, since the excavated material is mixed in the reflux water F2, if the excavated material is large, the gap between the inner pipe 110 and the power cable 1 may be clogged. In order to cope with this, in the present embodiment, a tapered surface 111b is formed at the distal end portion of the inner tube 110, and the inner surface of the inner tube 110 (the inner surface of the bit portion 111) is directed toward the distal end side on the digging direction side. The funnel is gradually expanded in diameter. By doing so, the reflux water F2 mixed with the excavated material does not suddenly enter the narrow gap between the rod 112 portion of the inner pipe 110 and the power cable 1, but becomes a wide gap like a funnel. While being agitated on the inner surface of the inner tube 110 on the tip side, that is, the inner surface of the rotating bit portion 111, the inner tube 110 is smoothly taken into the gap between the rod 112 (inner tube 110) and the power cable 1. Since this excavation makes the excavated material finer, clogging in the gap between the inner tube 110 and the power cable 1 can be suppressed.

  Further, since the groove 112a as shown in FIG. 3 is formed on the inner surface of the rod 112, a vortex phenomenon occurs in the gap between the inner tube 110 and the power cable 1, so that the excavated object can be quickly moved backward. Can be carried out. If the excavated material is clogged in the gap between the inner pipe 110 and the power cable 1, the clogged excavated material will move to the enlarged diameter portion on the inner surface of the bit portion 111 by rotating the inner tube 110 in the reverse direction. Since it is pushed out, by continuing to rotate the inner tube 110 at that position, the excavated material can be stirred and crushed on the inner surface of the bit portion 111, and clogging can be eliminated. Further, when the excavated material is clogged in the gap between the inner pipe 110 and the power cable 1, the clogged excavated material is broken by the groove 112a by repeating the forward and reverse rotations of the inner tube 110 several times. Therefore, clogging is eliminated.

  Further, the diameter of the front end side of the inner pipe 110 in the digging direction is larger than that of the rear end side, and the gap between the inner pipe 110 and the outer pipe 120 at the front end portion in the digging direction is reduced. The water pressure of the water injection F0 rises at the front end portion in the digging direction (without providing a separate pressurizing device on the rear end side of 100), and the squirting water F1 spouts out from the front end of the digging pipe 100. As a result, excavation capability is improved. By narrowing the gap between the inner tube 110 and the outer tube 120 at the front end portion of the digging pipe 100 in the digging direction, the water pressure can be increased at the front end portion in the digging direction without a pressurizing device.

  In addition, according to the double pipe structure of the present embodiment, the force of pushing the power cable 1 in the digging direction with respect to the power cable 1 by the reflux water F2 between the inner pipe 110 and the power cable 1 (like drag) (Force opposite to the reflux water F2). As a result, the power cable 1 can be pulled out to the access pit 3 with a weaker pulling force than in the past, and can be installed in a small space with a simple structure with a lower pulling capacity than in the past. The device 40 can be used. Therefore, construction in a small space is possible.

  Further, according to the double tube structure of the present embodiment, the outer tube 120 does not rotate and only the inner tube 110 rotates, and the inner tube 110 is supported by the outer tube 120 via the guide roller 114. By doing so, it is possible to suppress the shaking behavior of the inner tube 110 that moves forward while rotating in the horizontal and vertical directions. As a result, the excavation pipe 100 can be moved forward stably while suppressing damage to the power cable 1 due to excavation. Incidentally, since the excavation pipe 100 is configured to be able to bend at the connecting portion, it can follow the bending of the power cable 1. Moreover, if the digging pipe 100 is formed of a flexible material such as polyethylene, the power cable 1 can be made to follow.

  The outer pipe 120 also plays a role in preventing surrounding earth and sand from collapsing to the position of the inner pipe 110. As a result, it is possible to prevent a space from being formed in the ground by removing useless soil, and to prevent the ground surface from being depressed. In the present embodiment, a state where the distal end portion of the outer tube 120 in the digging direction is disposed near the rear end portion of the digging blade (carbide tip 111a) at the distal end portion in the digging direction of the inner tube 110 (bit portion 111). Therefore, the outer pipe 120 on the rear end side also advances in the direction of excavation at the same time after the excavation by the rotation of the inner pipe 110, so that it is possible to effectively prevent the surrounding earth and sand from collapsing.

  When the excavation using the excavation pipe 100 and the propulsion unit 10 is performed as described above, the power cable 1 is separated from the surrounding objects and pulled out by the extraction device 40 and then removed. In the stopped state, the digging pipe 100 is pulled out by pulling in the direction opposite to the digging direction while the digging pipe 100 is reversely rotated by the propulsion device 10. Finally, a fluidizing agent or the like is poured from the start pit 2 to fill the space remaining after the excavation pipe 100 is pulled out. Note that only the inner tube 110 may be pulled out to leave the outer tube 120. In this case, it is not necessary to perform the process of filling the space. The outer tube 120 can also be used as a conduit for laying a new power cable.

  As described above, according to the present embodiment, using the dug pipe 100 having a double-pipe structure, between the inner pipe 110 and the outer pipe 120 and between the inner pipe 110 and the power cable 1. While flowing water, the inner pipe 110 is rotated and the excavation pipe 100 is excavated so that the power cable 1 is separated from the surroundings, so that the water flow suitable for removal of the power cable 1 can be obtained. The power cable 1 can be easily removed.

  Further, according to the present embodiment, the start pit 2 and the arrival pit 3 are excavated in the buried path of the power cable 1, and the double pipe structure of the excavation pipe 100 is used to connect the inner pipe 110 and the outer pipe 120. And by flowing the water between the inner pipe 110 and the power cable 1, the inner pipe 110 is rotated, so that the power cable 1 is separated from the surrounding objects, thereby being buried directly by a buried method. Even when there is a structure such as a building on the ground surface above the power cable 1 or when there is another buried object near the power cable 1, the power cable 1 can be removed well. .

  In the above-described embodiment, the case where the removal target is the power cable 1 has been described. However, the removal target is not limited to this, and for example, a communication cable, a gas pipe, a water pipe, or the like may be the removal target. . The present invention is widely applicable when removing underground long objects.

  Further, in the above-described embodiment, the case where the present invention is used for removing the underground long object buried by the direct burying method has been described. However, it is buried by another burying method such as a pipe burying method. It can also be used when removing a long underground object. When the present invention is used to remove an underground long object buried by a pipe burying method, the outer pipe 120 can protect the pipe line, so that the underground long object can be removed without damaging the pipe line. It becomes like this. Moreover, if the outer pipe | tube 120 is not extracted after removal of a long underground thing, it can also be used as a new pipe line.

  In the above-described embodiment, the case where the excavating blade (carbide tip 111a) is attached to the inner tube 110 (bit portion 111) and only the inner tube 110 is rotated without rotating the outer tube 120 has been described. The excavating blade may be attached to the outer tube, and only the outer tube may be rotated. However, in the case of the direct embedding method as in the above-described embodiment, if the outer tube 120 is rotated by attaching a drilling blade to the outer tube 120, the surrounding earth and sand may be collapsed. It is preferable to rotate only the inner tube 110 as in the above-described embodiment.

  On the other hand, in the case of the pipe burial method, if the inside of the pipe does not draw in earth and sand, the inner pipe protects long underground objects such as power cables, while rotating the outer pipe to which the excavating blade is attached. Since it is possible to dig while cutting the fixed object, there is no problem even if only the outer tube is rotated. In the case of the pipe burying method, there are few cases where the fixed object is fixed to a long underground object such as a power cable over the entire length, and there is a case where the fixed object exists in a section of 10 m or less in the middle of the total length. The majority. In this case, in order to feed the inner and outer pipes to the point where the fixed object is located and rotate it when it hits the fixed object, the underground long object such as the power cable cannot be seen, and the underground object is damaged. There is a risk to give. Therefore, the risk can be avoided when the excavating blade is attached to the outer pipe without attaching the excavating blade to the inner pipe and only the outer pipe is rotated for excavation. Moreover, also when rotating only the outer pipe | tube with which the excavation blade was attached, the structure which the inner pipe | tube protrudes in the digging direction rather than the outer pipe | tube is preferable like the above-mentioned embodiment. Further, it is preferable that the flow of water is configured to flow (F0, F1, F2) similarly to the above-described embodiment. That is, a configuration similar to that shown in FIGS. 2 and 4 is preferred except that the attachment position of the excavation blade is changed from the inner tube to the outer tube, and the outer tube is rotated and the inner tube is not rotated.

  In the above-described embodiment, the squirting water F1 is ejected from the gap between the inner pipe 110 and the outer pipe 120, and the reflux water F2 is returned from the gap between the inner pipe 110 and the power cable 1. The squirting water may be ejected from the gap between the inner tube 110 and the power cable 1, and the reflux water may be returned from the gap between the inner tube 110 and the outer tube 120. However, if this is done, the erupted water will go in the outer circumferential direction of the digging pipe, and there is a risk of damaging the earth and sand around the digging pipe, so the water flow is as in the above embodiment. It is preferable to do.

  Furthermore, in the above-described embodiment, the case where the excavation pipe 100 has the double pipe structure of the inner pipe 110 and the outer pipe 120 has been described, but a triple pipe structure or a quadruple pipe structure may be used. In short, the excavation pipe has a multi-pipe structure, and the flow path of the jet water and the path of the reflux water may be independent paths.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Power cable (long underground)
2 start pit 3 arrival pit 10 propulsion device 20 water supply section 30 drainage section 40 drawing device 100 digging pipe 110 inner pipe 111 bit section 111a cemented carbide tip 112 rod 112a groove 113 rod coupling 114 guide roller 120 outer pipe F0 water injection F1 jet water F2 reflux water

Claims (3)

It is a method for removing long underground objects buried in a pipe burial method,
Installing a digging pipe so as to interpolate the long underground object, and installing a propulsion device that applies rotational force and pushing force to the digging pipe; and
Installing a water supply unit for supplying water to the excavation pipe;
Including
An inner tube into which the underground long object is inserted; and an outer tube disposed on the outer peripheral side of the inner tube;
Using the digging pipe provided with a digging blade at the tip of the digging direction of either the inner pipe or the outer pipe, the outer surface of the inner pipe and the outer surface are supplied by supplying water at a predetermined water pressure from the water supply unit. Water is allowed to flow toward the tip of the digging pipe through the gap between the inner surface of the outer pipe, and the outer surface of the inner pipe is narrower than the other parts with the diameter of the tip part in the digging direction being larger than the rear end part. By digging the digging pipe in the extending direction of the underground long object by rotating the pipe provided with the digging blade while spouting the water from the tip part in the digging direction of the gap, The excavated water is excavated in cooperation with the ejected water and the excavating blade, and the water mixed with the excavated material passes through the gap between the inner surface of the inner pipe and the outer surface of the underground long object. Further comprising refluxing in the direction of the propulsion device,
Removal method for long underground objects. The inner surface of the inner pipe has a tapered surface on the front end side and is formed in a funnel shape having a diameter gradually increased toward the front end side in the digging direction. A wide gap is formed at the tip of the direction,
In the step of refluxing the water in the direction of the propulsion device, the water mixed with the excavated material is refluxed in the direction of the propulsion device while being stirred in the wide gap.
The removal method of the underground long thing of Claim 1. Further comprising a step of installing a pulling device for pulling the underground long object,
The removal method of the underground long thing of Claim 1 or Claim 2.

Images