JP3761983B2 - Replacement method for buried pipes - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a buried pipe exchanging method in which a new resin polyethylene pipe is simultaneously drawn into a removed trace when a buried pipe laid underground as a supply pipeline for gas, water, etc. is pulled out.
[0002]
[Prior art]
The supply pipeline for gas, water, etc. is a piping system in which supply pipes for drawing gas, water, etc. are branched from the main and branch pipes of low-pressure pipes buried under the road. .
Some of the above-mentioned supply pipes are left unused in a state in which pipes are buried in the ground due to rebuilding of a customer's house. It is stipulated that such an unused pipe line is pulled out and removed because it may cause leakage or ground subsidence if left untreated.
[0003]
Conventionally, the prior art disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2-292590 and 3-9188 has been proposed for pulling out and removing such unused pipes. In this prior art, a pipe to be removed is separated from a conduit, and an end of the pipe to be removed is gripped by a drawing device and pulled out.
[0004]
[Problems to be solved by the invention]
Conventionally, the processing of the pipe line performed using the above-described prior art has merely performed an operation of pulling out the buried pipe and removing it.
Recently, a supply pipe in which a steel pipe called a white gas pipe is embedded is replaced with a resin-made polyethylene pipe (hereinafter referred to as a PE pipe) for earthquake countermeasures.
In this case, the conventional method employs a method in which a new PE pipe is drawn in by another process after the buried pipe is drawn. However, according to such a construction method, the work required for pulling in is different from the drawing work. Since it takes time, the replacement work takes a lot of time, and once the buried pipe is pulled out, the surrounding soil collapses into the cavity in the soil caused by the pulling out, so the new PE pipe is pulled in. Another problem is that work is not performed properly and workability is extremely poor.
[0005]
Further, as a method for replacing an old pipe buried in the ground with a new pipe, there are known prior arts described in, for example, Japanese Patent Application Laid-Open Nos. 57-120789 and 1-126484. However, according to this construction method, there is a problem that the old buried pipe remains in the ground because the old pipe is pulled in the direction of the pipe axis with a breaking device called a pipe splitter.
[0006]
In view of the above-described problems, an object of the present invention is to provide a buried pipe exchanging method capable of simultaneously drawing in a new resin pipe when a buried pipe laid in the ground is pulled out and removed.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the present invention installs a required drawing device in the first work pit with respect to the buried pipe laid between the first work pit and the second work pit. Then, one end of the buried pipe is held by the drawing device, and the other end of the buried pipe exposed in the second work pit is connected with a replacement resin pipe via a connecting means. From the side of the working pit, the filler is provided with a filler supply means for introducing a filler such as a mortar containing a lubricant component into the pipe of the buried pipe through one end of the buried pipe sandwiched between the drawing devices, and this filler, has an opening for the outflow from the other end of the buried pipe, during the step of withdrawing the buried pipe by the pulling device, the exchange resin pipe to be drawn into withdrawal path of the buried pipe is connected to the other end of the buried pipe by said connecting means Live by pulling out the outer circumference and buried pipe Cavity portion and construction as simultaneously performing the pull-in operation of the pull-out operation and the resin pipe buried pipes while injecting the filling material between the inner wall, the connecting means comprises a discharge hole of the filler Together with a locking member locked to the other end of the buried pipe, and the filler discharged from the discharge hole flows along the outer peripheral surface shape of the connecting means, and the replacement resin pipe and the hollow portion It is characterized by entering into the gap between the inner wall .
[0008]
Further, according to the present invention, the replacement resin pipe has an outer diameter slightly smaller than the outer diameter of the buried pipe, and the difference in the outer diameter dimension serves as an injection space for the filler. This is one of the features.
[0009]
[Action]
According to the construction method of the present invention, at the time of the buried pipe drawing process, the replacement resin pipe is simultaneously drawn into the drawing path, and the removal work of the buried pipe and the drawing work of the new PE pipe are simultaneously achieved.
At this time, the replacement resin pipe is drawn immediately after the buried pipe is drawn, and the resin pipe is drawn before the inside of the hollow of the drawing path is collapsed. Retraction is performed in a small state.
In addition, when the resin pipe is retracted, a filler such as a mortar containing a lubricant component flows out from the other end of the buried pipe through the inside of the buried pipe to be drawn out as a passage. This filler is injected between the inside and the inside of the cavity, and this filler exhibits a sliding action, so that the sliding resistance is small, and the pull-in resistance of the replacement resin tube can be greatly reduced.
As a result, it is possible to simultaneously perform the pull-out operation of the buried pipe and the pull-in work of the PE pipe without greatly changing the conventional drawing apparatus.
[0010]
In addition, since the above filler is injected between the outer periphery of the drawn resin tube and the inner wall of the hollow portion, the hollow portion is not generated on the outer periphery of the drawn resin tube, and there is no problem around the drawn resin tube. Equal subsidence and ground subsidence can be prevented.
[0011]
Furthermore, in the invention described in claim 2, by setting a difference in the outer diameter between the new resin pipe for replacement and the buried pipe to be removed, the drawing resistance of the buried pipe can be reduced while reducing the drawing resistance of the buried pipe. A sufficient filler injection space is formed in the portion, and the occurrence of land subsidence due to the collapse of the cavity can be reliably prevented.
[0012]
【Example】
The details of the present invention will be described below with reference to the illustrated embodiments.
FIG. 1 is a schematic view showing an embodiment of the buried pipe exchanging method according to the present invention. In FIG. 1, reference numeral 1 denotes a buried pipe to be pulled out in the exchanging method according to the present invention. Reference numeral 1 denotes a supply pipe branched from a conduit 2 (main pipe or branch pipe) buried under a road as a gas supply pipeline and drawn into a demand destination. In the following description, the buried pipe 1 is referred to as a removal pipe.
[0013]
When the removal tube 1 is pulled out, the connection with the conduit 2 is first disconnected by an appropriate means. As this method, the work pit B is excavated by excavating the road side, and the connection portion between the conduit path 2 and the removal pipe 1 exposed in the pit B is separated.
The other end in the extending direction of the removal pipe 1 separated from the conduit 2 is exposed in a work pit A that is cut out in the residential land of the customer, and a drawing device 7 described later is installed in the work pit A. Then, the end of the removal tube 1 is held by the drawing device 7.
One end of the removal pipe 1 exposed in the work pit B is connected to an end of a new pipe 4 for replacement through connection means 3 described later. In this embodiment, a polyethylene pipe (PE pipe) having high corrosion resistance is used as the new pipe 4 for replacement. The outer diameter of the new pipe (hereinafter referred to as PE pipe 4) is the removal pipe 1. A PE pipe 4 having an outer diameter slightly smaller than the outer diameter of the pipe is used.
Thus, in the underground cavity C after the removal pipe 1 is pulled out, there is a gap indicated by a symbol S in FIG. 2 between the outer peripheral surface of the replacement PE pipe 4 and the inner wall surface of the cavity C. The gap S is formed as a filler injection space to be described later.
[0014]
As shown in FIG. 2, the connecting means 3 is provided with a rotatable hook member 3A that forms a connecting portion at both ends in the longitudinal direction. The hook member 3A is hooked with hook members of locking members 5 and 6 fixed to the end portion of the removal pipe 1 and the end portion of the replacement PE pipe 4, respectively, and the removal pipe 1 is connected via the connecting means 3. And the replacement PE pipe 4 are integrated with each other.
[0015]
The locking member 5 on the removal tube 1 side is capable of closing the terminal portion of the removal tube 1 and is formed with a plurality of discharge holes 5A penetrating in the thickness direction along the circumferential direction. In the present embodiment, the cross-sectional shape of the discharge hole 5A is a tapered shape in which the connecting means 3 side has a small diameter along the longitudinal direction of the removal pipe 1, and the filler flowing inside the discharge hole 5A is discharged. The speed can be increased.
[0016]
The locking member 6 provided on the side of the replacement PE pipe 4 is formed with a conical head having a hook member that engages with the hook member 3A of the connecting means 3, and a part of the head is inside the connecting means 3. By entering, the replacement PE pipe 4 and the outer peripheral surface are made continuous. The terminal part of the replacement PE pipe 4 is integrated with the locking member 6, and when the removal pipe 1 is moved in the direction in which the removal pipe 1 is pulled out (direction indicated by the arrow D in FIG. 1), it is locked via the connecting means 3. By pulling the member 6, the PE pipe 4 can move in conjunction with the removal pipe 1.
[0017]
The end of the removal pipe 1 exposed in the work pit A is held by a drawing device 7 installed in the work pit A.
The pulling device 7 of this embodiment has a pair of upper and lower clamp rolls 7A and 7B that can obtain a predetermined holding force by a hydraulic cylinder, and the end of the removal tube 1 is held between the clamp rolls 7A and 7B. The removal tube 1 can be pulled out and moved in the direction indicated by the arrow D in FIG. 1 by rotation.
Although the details of the clamp rolls 7A and 7B equipped in the drawing device 7 are not shown, when the removal pipe 1 is pulled out, the pipe body of the pipe 1 as shown by a dotted line in FIG. Although it is crushed into an oval shape, it is configured to be pulled out in a form that can form a passage space inside the removal tube 1.
[0018]
Connected to the end of the removal pipe 1 drawn by the drawing device 7 is a supply path 8A for a filling material having the inside of the removal pipe 1 as a passage. The supply path 8A for the filler is composed of a hose connected to the filler injection machine 8 disposed on the ground portion on the work pit A side, and the filler from the filler injection machine 8 is removed from the removal pipe 1. It can be introduced sequentially into the pipe.
In this embodiment, the filler is a mortar containing a lubricant component such as bentonite, and the pressure from the compressor 9 attached to the filler injector 8 (pressure in the direction indicated by arrow F in FIG. 2). ) To be introduced into the tube of the removal tube 1 as the pulling-out operation of the removal tube 1 is started.
[0019]
The filler introduced into the pipe of the removal pipe 1 flows out from the discharge hole 5A of the locking member 5 as shown by an arrow P in FIG. The filler that has flowed out from the locking member 5 flows along the outer shape of the connecting means 3, the outer peripheral surface of the replacement PE pipe 4 having a smaller outer diameter than the removal pipe 1, the inner wall surface of the cavity C, It flows into the cavity C using the injection space formed by the gap S between the two.
[0020]
Since the present embodiment is configured as described above, the following procedure is executed when the buried pipe (removal pipe 1) is replaced.
First, at the time of replacement work, the work pit B for separating the removal pipe 1 from the conduit path 2 is excavated by excavation, and the end of the removal pipe 1 is separated from the conduit path 2 and exposed to open the terminal portion. In addition, the service channel which becomes a separation port is hermetically sealed in the conduit 2 from which the removal pipe 1 is separated.
[0021]
Next, one end of the connecting means 3 is fixed to the pipe end of the removal pipe 1 exposed in the work pit B. As a method for fixing the connecting means 3 to the pipe end of the removal pipe 1, in the case of the present embodiment, a fastening means is used in order to enable recovery of the connecting means 3 after replacement. A replacement PE pipe 4 is connected to the connection means 3 in advance, and the connection means 3 is fastened to the pipe end of the removal pipe 1 so that the removal pipe 1 and the replacement PE pipe 4 can be interlocked. Is done.
[0022]
When the connection between the removal pipe 1 and the replacement PE pipe 4 is completed, the removal pipe 1 is pulled out from the buried position by the pulling device 7. In this case, the extraction device 7 is sequentially extracted from the embedded position by the rotation of the clamp rolls 7A and 7B.
When the removal pipe 1 begins to be pulled out from the buried position, the replacement PE pipe 4 connected by the connecting means 3 in conjunction with the drawing is sequentially drawn into the underground cavity C generated by the drawing.
[0023]
On the other hand, the filler is sequentially pumped into the pipe of the removal pipe 1 through the filler supply path 8A by the operation of the filler injection machine 8 and the compressor 9 in accordance with the time when the removal pipe 1 is pulled out. The filler is pressurized in the pipe of the removal pipe 1 by the pressure from the compressor 9 and flows out from the discharge hole 5 </ b> A provided in the locking member 5.
The filler discharged from the discharge hole 5 </ b> A of the locking member 5 flows along the outer peripheral surface shape of the connecting means 3, and is formed by the difference in outer diameter between the removal pipe 1 and the replacement PE pipe 4. It enters the gap S (see FIG. 2) and is injected into the cavity C that is created after the removal tube 1 is pulled out.
When the filler injected into the cavity C comes into contact with the outer peripheral surface of the replacement PE pipe 4, the sliding resistance of the PE pipe 4 is reduced, and when the filler is cured after the PE pipe 4 is drawn, The effect of preventing the part C from collapsing is achieved.
[0024]
The drawing device 7 stops its operation when the entire length of the removal pipe 1 is drawn and the tip of the replacement PE pipe 4 is exposed in the work pit A. The replacement PE pipe 4 exposed in the work pit A is made ready for use as a new pipe by removing the connecting means 3 from its tip.
[0025]
【The invention's effect】
As described above, according to the first aspect of the present invention, the replacement PE pipe is simultaneously drawn into the drawing path during the removal pipe drawing process, and the removal pipe is removed and the new PE pipe is drawn in. Work can be accomplished at the same time.
At this time, the replacement PE pipe is pulled in immediately after the removal pipe is pulled out, and the PE pipe is pulled in before the inside of the cavity generated in the extraction path is collapsed. When the PE pipe is retracted, a filler such as a mortar containing a lubricant component flows out from the other end of the removal pipe, with the inside of the removal pipe being pulled out as a passage. As a result of being injected between the outer periphery of the PE tube to be wound and the inner wall of the hollow portion in the ground, this filler exhibits a sliding action, so that the sliding resistance is greatly reduced, and the replacement PE tube is retracted. Retraction of the PE tube can be achieved with the resistance greatly reduced.
As a result, the removal and removal work of the removal pipe and the pull-in work of the PE pipe can be achieved simultaneously without greatly changing the conventional drawing device.
[0026]
Moreover, the above filler is injected between the outer circumference of the drawn PE pipe and the inner wall of the cavity, so that no cavity is generated on the outer circumference of the drawn PE pipe. Uneven settlement and land subsidence can be prevented.
[0027]
Further, in the invention described in claim 2, by setting a difference in the outer diameter between the new replacement PE pipe and the removal pipe to be removed, the pull-in resistance of the PE pipe can be reduced, and at the same time, the removal cavity of the removal pipe A sufficient filler injection space is formed in the portion, and the occurrence of ground subsidence due to the collapse of the cavity can be reliably prevented.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram for explaining a replacement mode of a buried pipe according to the present invention.
FIG. 2 is a partial cross-sectional view for explaining the configuration of a connecting means used when replacing the buried pipe shown in FIG.
[Explanation of symbols]
1 Buried pipe to be pulled out (removal pipe)
3 Connecting means 4 Replacement PE pipe 5, 6 Locking member 5A Filler discharge hole 8 Filler injection machine 9 Compressor A, B Work pit

Claims (2)

For the buried pipe laid between the first work pit and the second work pit, a required drawing device is installed in the first work pit, and one end of the buried pipe is held by the drawing device. Further, a replacement resin pipe is connected to the other end of the buried pipe exposed in the second work pit via a connecting means, and is sandwiched by the drawing device from the first work pit side. It is provided with a filler supply means for introducing a filler such as a mortar containing a lubricant component into the pipe of the buried pipe through one end of the buried pipe, and has an opening through which the filler flows out from the other end of the buried pipe. , during a process of pulling out the buried pipe by the pull-out device, and the outer periphery of the replacement resin pipe to be drawn into the withdrawal path of the buried pipe is connected to the other end of the buried pipe by the coupling means, the cavity caused by the withdrawal of the buried pipe Pour the above filler between the inner wall A pull-in operation of the pull-out operation and the resin pipe buried pipes and construction as simultaneously performed while,
The connecting means has a discharge hole for the filler and is connected to a locking member locked to the other end of the buried pipe,
The buried pipe replacement method, wherein the filler discharged from the discharge hole flows along the shape of the outer peripheral surface of the connecting means and enters the gap between the replacement resin pipe and the inner wall of the cavity .   2. The buried pipe exchanging method according to claim 1, wherein the replacement resin pipe has an outer diameter slightly smaller than an outer diameter of the buried pipe, and the difference in the outer diameter dimension is the injection of the filler. A buried pipe replacement method characterized by being a space.

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