JP3613538B2 - Steel pipe retraction method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a steel pipe retracting method for laying a steel pipe that becomes a distribution pipe for gas or the like in the ground by non-open cutting.
[0002]
[Prior art]
As a method of laying pipes by non-open cutting, a conventional method has been proposed in which a road-mounted type propulsion machine is installed on the ground, drilling a borehole into the ground in the first process, and drawing the pipe into the drilled borehole in the second process. Has been.
[0003]
5 (A) and 5 (B) show the above-described drawing method, (A) shows the drilling process of the borehole, and (B) shows the pipe drawing process. The pipe laying path is provided with a start shaft a on one side and a reaching shaft b on the other side, and a road-mounted propulsion device c is installed on the ground on the start shaft a side. The propulsion unit c includes a guide drill unit that performs an action of feeding a rotating rod with a required propulsive force or pulling it back with a required pulling force.
[0004]
In the excavation process shown in FIG. 5 (A), a drill head f is attached to the tip of a rod e fed out from a propulsion device c, and the drill head f enters the ground while rotating to reach the reaching shaft from the start shaft a. The drill head f is advanced along the path leading to b. At this time, bentonite muddy water is jetted from the tip of the drill head f, and the water flow advances while cutting the soil, and rods e are sequentially added so that a borehole is dug into the ground of the route to the reaching shaft b. ing.
During this excavation, the signal g from the transmitter incorporated in the drill head f is detected by the ground detector h to confirm the tip position of the boring, and the excavation is performed while correcting the direction during excavation by remote control from the ground. Like to do.
[0005]
Next, in the retraction process shown in FIG. 5 (B), the drill head f is removed on the side of the reaching shaft b, and instead of this, at the end of the rod e, a hole expansion reamer n adapted to the buried pipe diameter, and the retraction target With the pipe (steel pipe) m connected in series, the rod e is pulled back by the pulling force of the propulsion unit c. Then, after the drawing is completed, the steel pipe m is suspended again by the crane j, and after the welding, the drawing is started again. At this time, the bentonite mud is pulled back from the expanded reamer n while jetting again, and in this step, the drawing target pipe m is drawn into the borehole.
[0006]
[Problems to be solved by the invention]
By the way, in the case of the construction method using the above-mentioned road-mounted propulsion device, when the pull-in target pipe is a steel pipe, the pull-in distance per day is about 80 m due to the performance of the propulsion device.
In the case of the above-mentioned construction method, steel pipes (about 12 m in total length) are suspended one by one in the reaching shaft and are pulled in while being sequentially welded. Therefore, the size of the reaching shaft is required to be at least 12 m. Here, it takes about 6 hours to form this reach shaft, and it takes 4 hours to backfill. Therefore, until construction is completed, it is customary to close with an iron plate called a lining plate.
[0007]
In consideration of such construction circumstances, for example, when a 320 m steel pipe is pulled in, the construction takes 4 days, and four reaching shafts must be formed. Therefore, the problem that the cost of forming the reaching shaft and the cost of the lining board are enormous is derived.
[0008]
The present invention has been devised to solve the above-mentioned problems, and provides a steel pipe retraction method that allows steel pipe retraction to be performed appropriately and inexpensively based on the idea of effectively using a road-mounted propulsion device. It is intended to do.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the construction method according to the present invention is a steel pipe retraction method for drawing a steel pipe over a section of a work shaft formed in a pipe laying path,
In the first step, a preparation pipe is drawn into each shaft section of a plurality of work shafts formed on the ground, and the drawn-in preparation pipes are connected to each other in the shaft to form one connection preparation pipe,
In the 2nd process, it constructs so that a steel pipe may be drawn in in the above-mentioned connection preparation pipe.
[0010]
Also, as a concrete construction method, on the ground on one side of the above work shaft, installed on the road with a guide drill unit that performs the action of feeding out the rotating rod with the required propulsive force or pulling it back with the required retracting force Type propulsion machine,
In the first step, a drill head is attached to the tip of a rotating rod fed out from the road-mounted propulsion device, and the drill head is rotated and entered into the ground to work from one side work shaft to the other side. Drill a boring hole into the ground to the shaft, remove the drill head from the work shaft on the other side, and replace it with an expanded reamer that matches the diameter of the prepared tube at the rod end, and a prepared tube In a state where they are connected in series, the rod is pulled back by the pulling force from the front by the propulsion device, and the preparation tube is pulled into the boring hole,
After laying of the preparation pipe is completed over all work shaft sections formed in the pipe laying path, the drawn preparation pipes are connected to each other in the shaft to form one connection preparation pipe,
In the 2nd process, it constructs so that a steel pipe may be drawn in in the above-mentioned connection preparation pipe.
[0011]
Further, the preparatory pipe is a polyethylene pipe, and as a means for drawing the steel pipe into the preparatory pipe, a winch installed in the work shaft on the terminal side is used, and if necessary, a lubricant is provided on the inner surface of the polyethylene pipe. The steel pipe is retracted after the coating is applied.
[0012]
[Action]
According to the above-described drawing method, a preparation pipe such as a polyethylene pipe is drawn into the soil before the steel pipe is drawn, and then the steel pipe is drawn into the preparation pipe. Therefore, the steel pipe is not in contact with the soil but is in contact with only the preparation pipe, the frictional resistance due to the steel pipe drawing is reduced, and the distance of the steel pipe drawing distance (80 m) per day can be extended. In addition, when a lubricant is applied in the preparation pipe, the frictional resistance due to the pull-in is further reduced, and the steel pipe pull-in distance can be further extended.
[0013]
Further, when a polyethylene pipe is used as the preparation pipe, the polyethylene pipe can be bent, so that the size of the reaching shaft is not required as much as 12 m, and the size of the reaching shaft for drawing the polyethylene pipe having a diameter of 200A is about 5m is enough. Therefore, it is possible to reduce the cost for forming the reaching shaft, and further, since the backfilling on the same day is possible, the lining plate is not required, and the construction cost can be greatly reduced.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 1 is a first work shaft, reference numeral 2 is a second work shaft, and reference numeral 3 is a third work shaft.
In this embodiment, a steel pipe is laid between the first work shaft 1 and the third work shaft 3.
[0015]
First, as a first step, a polyethylene pipe 4 is drawn as a preparation pipe between the first work shaft 1 and the third work shaft 3. Here, the inner diameter of the polyethylene pipe 4 is slightly larger than the outer diameter of the steel pipe to be drawn.
As shown in FIG. 1, a road-mounted propulsion device 5 is installed on the ground of the first shaft 1. This propulsion unit 5 is equipped with a guide drill unit 51 that feeds the rotating rod 6 with the required propulsive force and pulls it back with the required pulling force as in the prior art. Not equipped with a power unit truck as a power source. Then, a drill head 7 is attached to the tip of the rotating rod 6 fed out from the propulsion unit 5, and the drill head 7 is caused to enter the ground while rotating, and drilled into the ground along the path from the first shaft 1 to the second shaft 2. Drill a hole. Next, the drill head 7 is removed on the second shaft 2 side, and instead, the expanded reamer 8 matched to the diameter of the polyethylene pipe 4 and the polyethylene pipe 4 are connected in series to the rod end. Then, the rod 6 is pulled back by the pulling force from the front by the propulsion unit 5 and the polyethylene pipe 4 is pulled into the boring hole. Further, the polyethylene pipe 4 is laid between the second shaft 3 and the third shaft 3 in the same manner as described above.
Then, the laid polyethylene pipes 4 are connected to each other in the second shaft 2 to complete the laying of the polyethylene pipe 4 between the first work shaft 1 and the third work shaft 3.
[0016]
As another method of drawing the polyethylene pipe 4 between the first work shaft 1 and the third work shaft 3, as shown in FIG. 2, first, propulsion is performed between the first shaft 1 and the second shaft. A drill head 7 is attached to the tip of the rotating rod 6 fed out from the machine 5, and the drill head 7 is made to enter the ground while rotating while checking the direction by the detector 8, thereby forming a borehole. Next, the propulsion device 5 is moved toward the second shaft 2 and the second rotating rod 6 ′ is propelled between the second shaft 2 and the third shaft 3 to form a borehole. Then, as shown in FIG. 3, the first rotating rod 6 and the second rotating rod 6 ′ are connected in the second shaft 2. And the expansion reamer 8 matched to the diameter of the polyethylene pipe 4 and the polyethylene pipe 4 are connected in series at the end of the connecting rod, and the connecting rod is pulled back by the pulling force from the front by the propulsion unit 5. Then pull the polyethylene pipe 4 into the borehole.
Then, the laying of the polyethylene pipe 4 is completed between the first work shaft 1 and the third work shaft 3.
[0017]
Next, the steel pipe 11 is drawn into the polyethylene pipe 4 laid in the first process as the second process.
As shown in FIG. 4, first, the pulling wire 13 is inserted into the polyethylene pipe 4. Next, the first stage steel pipe 11 is installed in the third shaft 3. One end of the pulling wire 13 is connected to the winch 12 installed in the first shaft 1, and the other end of the wire 13 is connected to the tip of the steel pipe 11. Then, the winch 12 is operated to pull the first stage steel pipe 11 into the polyethylene pipe 4. When the winch 12 is pulled to some extent, the pulling is temporarily stopped, and the next stage is stopped by the crane 10 installed on the ground near the third shaft 3. After the steel pipe 11 is suspended and the end of the steel pipe 11 is welded, the drawing is resumed and the steel pipe is drawn. In this way, the steel pipe 11 is drawn into the polyethylene pipe 4 sequentially.
[0018]
According to the drawing method as described above, the polyethylene pipe 4 is drawn into the soil before the steel pipe 11 is drawn into the soil, and then the steel pipe 11 is drawn into the polyethylene pipe 4. Therefore, the steel pipe 11 comes into contact with only the polyethylene pipe 4 without coming into contact with the soil, the frictional resistance due to the steel pipe 11 being pulled in is reduced, and the distance of the steel pipe pull-in distance per day can be extended. Further, by applying a lubricant in the polyethylene pipe 4 before the steel pipe 11 is drawn, the frictional resistance is further reduced, and the steel pipe drawing distance can be further extended.
[0019]
Moreover, since the polyethylene pipe 4 can be bent, the size of the work shaft is not required to be 12 m, and the size of the work shaft for drawing the polyethylene pipe 4 having a diameter of 200A is about 5 m. Therefore, the cost for forming the first shaft 2 and the second shaft 2 can be reduced, and further, since the backfill on the same day is possible, the lining plate is not required, and the construction cost is greatly increased. Can be reduced.
[0020]
As mentioned above, although the Example of this invention was described in detail, in the said Example, although demonstrated using the 1st shaft 1, the 2nd shaft 2, and the 3rd shaft 3 as a work shaft, this invention is not restricted to this. This can also be applied to the case where four or more work shafts are formed.
[0021]
【The invention's effect】
Thus, according to the present invention, as a stage before drawing the steel pipe, a preparation pipe such as a polyethylene pipe is drawn into the soil, and then the steel pipe is drawn into the preparation pipe. Therefore, the steel pipe is not in contact with the soil but is in contact with only the preparation pipe, the frictional resistance due to the steel pipe drawing is reduced, and the distance of the steel pipe drawing distance (80 m) per day can be extended. In addition, when a lubricant is applied in the preparation pipe, the frictional resistance due to the pull-in is further reduced, and the steel pipe pull-in distance can be further extended.
[0022]
Moreover, since the laid steel pipe is covered with the preparation pipe, it is possible to prevent aging such as corrosion due to external factors such as rainwater.
Further, when a polyethylene pipe is used as the preparation pipe, the polyethylene pipe can be bent, so that the size of the reaching shaft is not required as much as 12 m, and the size of the reaching shaft for drawing the polyethylene pipe having a diameter of 200A is about 5m is enough. Therefore, it is possible to reduce the cost for forming the reaching shaft, and further, since the backfilling on the same day is possible, the lining plate is not required, and the construction cost can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a first step according to the present invention. FIG. 2 is an explanatory diagram of another first step according to the present invention. FIG. 3 is an explanatory diagram of another first step according to the present invention. Explanatory drawing of the second step [Fig.
DESCRIPTION OF SYMBOLS 1 1st work shaft 2 2nd work shaft 3 3rd work shaft 4 Polyethylene pipe 5 Road-mounted propulsion device 51 Guide drill unit 6 Rod 7 Drill head 8 Expanded reamer 9 Detector 10 Crane 11 Steel pipe 12 Winch 13 Towing wire

Claims (5)

A steel pipe drawing method for drawing a steel pipe over a section of a work shaft formed in a pipe laying path,
In the first step, a preparation pipe is drawn into each shaft section of a plurality of work shafts formed on the ground, and the drawn-in preparation pipes are connected to each other in the shaft to form one connection preparation pipe,
In the 2nd process, it constructs so that a steel pipe may be drawn in in the above-mentioned connection preparation pipe. On the ground on one side of the work shaft, a road-installed type propulsion unit having a guide drill unit that performs an action of feeding a rotating rod with a required propulsive force or retracting with a required pulling force,
In the first step, a drill head is attached to the tip of a rotating rod fed out from the road-mounted propulsion device, and the drill head is rotated and entered into the ground to work from one side work shaft to the other side. Drill a boring hole into the ground to the shaft, remove the drill head from the work shaft on the other side, and replace it with an expanded reamer that matches the diameter of the prepared tube at the rod end, and a prepared tube In a state where they are connected in series, the rod is pulled back by the pulling force from the front by the propulsion device, and the preparation tube is pulled into the boring hole,
After laying of the preparation pipe is completed over all work shaft sections formed in the pipe laying path, the drawn preparation pipes are connected to each other in the shaft to form one connection preparation pipe,
In the 2nd process, it constructs so that a steel pipe may be drawn in in the said connection preparation pipe, The drawing-in method of the steel pipe of Claim 1 characterized by the above-mentioned. The steel pipe drawing-in method according to claim 1 or 2, wherein the preparation pipe is a polyethylene pipe. The steel pipe drawing method according to claim 1 or 2, characterized in that the means for drawing the steel pipe into the preparation pipe is performed using a winch installed in the work shaft on the terminal end side. The steel pipe drawing method according to claim 1 or 2, wherein the steel pipe is drawn after applying a lubricant to the inner surface of the preparation pipe.

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