JP4060201B2 - Inner pipe connection method in drilling using a double pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for boring a natural ground around a tunnel using, for example, a double pipe, and more particularly, to a method for connecting an inner pipe disposed inside an outer pipe embedded in the natural ground.
[0002]
[Prior art]
In general, when excavating a tunnel in soft ground, before excavation work, drill from the face to the ground around the tunnel in the direction of excavation, and insert an injection pipe into this drilling hole. A method of constructing a supporting work by excavating the reinforced portion after injecting a solidifying agent to reinforce the natural ground is performed. However, this method has a problem in that work efficiency is poor and the construction period is prolonged because it is necessary to alternately repeat the reinforcement of the natural ground and the construction of the support work. Therefore, after constructing the advanced guide shaft in the tunnel excavation direction in advance, a bent steel pipe having a predetermined curvature is inserted and embedded from the side wall of the advanced guide shaft into the natural ground that becomes the arch part of the tunnel cross section of the main shaft Thus, a method for excavating a natural ground is proposed (for example, Patent Documents 1 and 2).
[0003]
By the way, in the above method, since the bent steel pipe itself is rotated to excavate the natural ground, not only the apparatus becomes large, but also the construction is difficult when the radius of curvature of the bent steel pipe is small. there were. Therefore, as shown in FIGS. 6 (a) and 6 (b), a steel pipe to be inserted into the natural ground 60 is a bent steel pipe (hereinafter referred to as an outer pipe) 51 having an injection hole 51h on its side surface, and an inner part of the outer pipe 51. And a tip device 53 having a tip bit 53b rotated by a motor 53a is attached to the tip of the inner tube 51 to excavate the natural ground 60. A curved boring device 50 is used in which the outer pipe 51 is inserted and buried in the natural ground 60. In this curved boring device 50, the outer tube 51 and the inner tube 52 are coupled by the swivel 54 in the advanced guiding shaft 61, and the outer peripheral surface of the outer tube 51 is held by the holder 55 </ b> H of the propulsion device 55 for propulsion. The outer pipe 51 and the inner pipe 52 are simultaneously inserted into the natural ground 60 while excavating the natural ground 60 with the tip device 53.
[0004]
Then, while repeating the step of propelling the outer tube 51 and the inner tube 52 by excavating the natural ground 60 and the step of extending the double tube by connecting the inner tube 52 and the outer tube 51 respectively, After the tube 51 has been inserted to a predetermined length, the tip device 53 and the inner tube 52 are recovered, and a packer 56p is provided in the outer tube 51 before and after the discharge port 56h as shown in FIG. The injection pipe 56 is inserted, and the ground solidifying agent pumped through the injection liquid transfer pipe 57 connected to the rear end portion of the injection pipe 56 is discharged into the outer pipe 51, The ground solidifying agent is injected from the provided injection hole 51h into the ground 60 around the tunnel to reinforce the ground 60 (for example, Patent Documents 1 and 2, Non-Patent Document 1, etc.).
[0005]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-160980 (pages 2, 3 and 1, 3)
[Patent Document 2]
No. 2002-242581 (pages 2, 3 and 1-3)
[Non-Patent Document 1]
Yoshitomo Kameoka, Taro Sugaya, “Curved Boring Method (TURIP Method)
Development, "Journal of Japan Society of Civil Engineers, April 1995 issue [0006]
[Problems to be solved by the invention]
By the way, the pressure from the surrounding natural ground 60 acts on the cross section of the bent steel pipe (outer pipe 51) in the natural ground as shown in FIG. The magnitude of this pressure, in the case of a straight tube which is generally buried in the ground is not greater than the direction of the pressure acting in the vertical direction of the surface of the natural ground is applied to the side surface. On the other hand, in the case such as a curved tube that is installed in the arch portion of the tunnel, its size is also the influence of the pressure difference between the upper and lower direction of the natural ground, but if overall view, the curvature of the outer tube 51 radially The pressure acting on the directional surface is greater than the pressure acting on the directional surface . Therefore, due to the pressure, the outer tube 51 is deformed so that its cross section is crushed in the direction of the radius of curvature of the bent tube (outer tube) 51 as shown in FIG. As described above, there is a problem that if the outer tube 51 is deformed, the recovery operation of the inner tube 52 is hindered.
Thus, a method of increasing the strength of the outer tube 51 by increasing the thickness of the outer tube 51 in the radius direction of curvature is also conceivable, but it is not practical to make such a circular tube. Further, when the thickness of the entire outer tube 51 is increased, there is a problem that the cost is increased.
[0007]
The present invention has been made in view of the conventional problems, and in the boring using the double pipe, even when the outer pipe is deformed by the pressure from the natural ground , the inner pipe can be easily recovered. An object of the present invention is to provide an inner pipe connection method that can be performed.
[0008]
[Means for Solving the Problems]
Invention of Claim 1 of this invention is a connection method of the inner pipe arrange | positioned in the bending pipe inserted in a natural ground by the boring using a double pipe, Comprising: On the outer peripheral side of the connection part of the said inner pipe A flange portion having four projecting pieces projecting in a direction deviated by a predetermined angle with respect to a radius of curvature which is a direction in which the bent pipe is crushed is provided , and the projecting pieces of the flange portion are connected to each other. It is characterized by this. Thus, even when the deformed curvature radius direction of the curved cross-sectional shape of an outer tube elbow tube, Ku such increasing the thickness of the curved tube, Ru can perform recovery operations of the inner tube readily .
[0009]
Further, the invention according to claim 2 is shifted by a predetermined angle on the outer peripheral side of the connecting portion of the inner pipe disposed in the straight pipe as the outer pipe with respect to the vertical direction of the natural ground, which is the direction in which the straight pipe is crushed. A flange portion having four projecting pieces projecting in the direction is provided, and the projecting pieces of the flange portion are connected to each other. With this, when the cross-sectional shape of the straight pipe is deformed in the vertical direction of the natural mountain, In addition, the recovery operation of the inner pipe can be easily performed.
According to a third aspect of the present invention, in the method for connecting the inner pipe in the boring using the double pipe according to the first or second aspect, the angle between the protruding pieces is 90 degrees.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a method for connecting inner pipes according to an embodiment of the present invention, in which 11 is a main body of a cylindrical inner pipe 10, and 12 is an end of the inner pipe main body 11, that is, the inner pipe 10, 10, the flange portion 12 has a curvature of the outer tube (bent tube) 20 indicated by an arrow in FIG. 2 (a) and (b). Four projecting pieces 13 projecting in a direction shifted by 45 degrees from the radial direction are provided. Further, each of the protruding pieces 13 is formed with a bolt insertion hole 14, and when connecting the inner pipes 10, 10, the protruding pieces 13, 13 of the front and rear flange portions 12, 12 are connected to each other. The connection is made by fastening means such as a bolt 15.
As a result, even when a force that crushes the outer tube 20 in the radius direction of curvature acts on the cross section of the outer tube 20, the outer tube 20 is held from the inside by the protruding piece 13 as shown in FIG. Therefore, not only can the center position be maintained, but the protruding piece 13 is 45 degrees away from the direction of the radius of curvature of the outer pipe 20 that is a bent pipe, that is, 45 degrees from the direction in which the outer pipe 20 is crushed. Since the protrusion 13 protrudes in the shifted direction, the protrusion 13 does not mesh with the outer tube 20. Therefore, Ru can be performed smoothly recovery of the tube 10 to be performed after the insertion of the outer tube 20.
Contact name as shown in FIG. 4 (a), the case of providing the projecting piece 13Z curvature radius direction of the outer tube 20, the outer tube 20, so deformed as shown in FIG. 4 (b) , you have want meshed with the flange portion 12 and the outer tube 20, the recovery work of the inner tube 10 becomes difficult.
[0011]
As described above, in the present embodiment, the four protruding from the end portion of the main body 11 of the inner tube 10, that is, the connecting portion of the inner tubes 10 and 10, in a direction shifted by 45 degrees from the radius of curvature of the outer tube 20. Since the flange portion 12 having the protruding piece 13 is provided, the protruding pieces 13 are connected to each other by the bolt 15, and the outer pipe 20 is held from the inner side by the protruding piece 13, even if pressure is exerted from, it is possible to hold the central position of the outer tube 20, than the protruding piece 13 is prevented from meshing with the outer tube 20, it is possible to perform the recovery of the inner pipe 10 smoothly it can.
[0012]
In the above embodiment, the curved boring using a bent pipe as the outer pipe 20 has been described. However, as shown in FIGS. 5A and 5B, when the outer pipe 20M is a straight pipe, the above-described case is performed. As described above, since the pressure P acting on the vertical surface of the natural ground is greater than the pressure p acting on the lateral surface, the protruding piece 13 is set at a predetermined angle with respect to the vertical direction of the natural ground of the outer tube 20M. If it is provided at a position rotated by 45 ° (here, 45 °), the center position of the outer tube 20M can be maintained even when the outer tube 20M is deformed so as to collapse in the vertical direction of the natural ground. the protruding pieces 13 than never meshes with the outer tube 20M, can be recovered inner tube 10 smoothly.
[0013]
Moreover, although the case where the four protrusion pieces 13 were provided in the flange part 12 was demonstrated in the said example, the number of the said protrusion pieces 13 is not restricted to this, Five or more may be sufficient. However, at this time, it is necessary to provide at least the protruding piece 13 positioned on the upper side of the outer tube 20 in a direction shifted from the radius of curvature of the outer tube 20.
In the above example, the double pipe for propelling the outer pipe 20 has been described. However, the present invention can also be applied to a double pipe for propelling the inner pipe 10. In this case, a hydraulic hose, a water supply hose, and the like can be disposed between the protruding pieces 13 and 13. Thereby, since the space in the inner pipe | tube 10 can be expanded, the efficiency of earth removal improves and work efficiency can be improved .
[0014]
【The invention's effect】
As described above, according to the present invention, a predetermined angular deviation from the curvature radius direction of the bent pipe provided on the outer peripheral side of the connecting portion of the inner pipe disposed in the bent pipe inserted into the natural ground by boring. direction in the flange portion is provided with four projecting pieces that project, this since so as to connect the protruding pieces with each other of the flange portion, even if the deformed curved pipe by pressure from the natural ground, the upper Symbol the recovered tubes can be easily performed.
In addition, when the outer pipe inserted into the natural ground is a straight pipe, if the protruding piece is provided at a position rotated by a predetermined angle with respect to the vertical direction of the natural ground, the pressure from the natural ground even if the straight tube is deformed, Ru can be performed recovered of the inner tube readily.
[Brief description of the drawings]
FIG. 1 is a diagram showing an inner pipe connection method according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a flange portion of an inner pipe according to the present embodiment.
FIG. 3 is a schematic view showing a deformed state of the outer tube when a natural mountain pressure is applied.
FIG. 4 is a view showing a flange portion of an inner tube having a protruding piece.
FIG. 5 is a diagram showing a natural mountain pressure acting on a straight pipe and a deformed state when the outer pipe is a straight pipe.
FIG. 6 is a diagram showing a configuration of a conventional curved boring apparatus.
FIG. 7 is a view showing a method of injecting a ground solidifying agent into a natural ground.
FIG. 8 is a diagram showing a natural pressure acting on the outer pipe.
[Explanation of symbols]
10 inner pipe, 11 inner pipe main body, 12 flange part, 13 protruding piece,
14 bolt insertion hole, 15 bolt, 20 outer tube.

Claims (3)

A method for connecting an inner pipe disposed in a bent pipe inserted into a natural ground by boring , wherein a predetermined angle is formed on the outer peripheral side of the connecting portion of the inner pipe with respect to a radius direction of curvature that is a direction in which the bent pipe is crushed. A method of connecting inner pipes in a boring using a double pipe, characterized in that a flange portion having four projecting pieces projecting in a shifted direction is provided and the projecting pieces of the flange parts are connected to each other. . A method for connecting an inner pipe arranged in a straight pipe inserted into a natural ground by boring , wherein a predetermined direction is provided on the outer peripheral side of the connecting portion of the inner pipe with respect to the vertical direction of the natural ground, which is a direction in which the straight pipe is crushed. A method of connecting inner pipes in a boring using a double pipe, characterized in that a flange part having four projecting pieces projecting in a direction shifted in angle is provided and the projecting pieces of the flange parts are connected to each other. . The method of connecting inner pipes in boring using a double pipe according to claim 1 or 2, wherein the angle between the protruding pieces is 90 degrees.

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