JP2014163089A - Coupling structure for natural ground reinforcing pipe, coupler, and natural ground reinforcing pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupling structure for a natural ground reinforcing pipe, which can enhance reliability of construction for natural ground reinforcement by reliably preventing a screw-coupled state of a cylindrical coupling member and the natural ground reinforcing pipe from being eliminated due to screw looseness.SOLUTION: In a coupling structure for a natural ground reinforcing pipe, at least one end of the natural ground reinforcing pipe 10 is provided with a male screw part 13; the male screw part 13 comprises right and left screw parts 131 and 132 that are formed in a longitudinal different area of the natural ground reinforcing pipe 10; a coupler 20 is provided with a female screw part 21 for being screwed to the male screw part 13 of the natural ground reinforcing pipe 10; and the female screw part 21 comprises a lap screw part 211 that is formed by making right and left screws overlap each other.

Description

  The present invention relates to a connection structure of a natural ground reinforcement pipe that is connected and placed so as to be added to a natural ground to be reinforced, a coupler, and a natural ground reinforcement pipe.

  Conventionally, a double-pipe drilling method is known as a method for placing a ground reinforcement pipe in a natural ground. In the example of the double-pipe drilling method of FIG. 10, a drill bit 3 is rotatably provided at the tip of the natural ground reinforcement pipe 1a via the casing shoe 2 and is inserted into the natural ground reinforcement pipe 1a. The drill bit 3 is attached to the tip of the hole rod 4a, and the ground force reinforcement pipe 1a is driven into the natural ground by transmitting the striking force P and the rotational force R from the hole rod 4a to the hole bit 3. And the natural ground reinforcing pipe 1a and the drilling rod 4a are connected to the natural ground reinforcing pipes 1b, 1c, etc. and the drilling rods 4b, 4c, etc. one after another, and the connected natural ground reinforcing pipes 1a to 1c etc. Will be placed until the required length is reached.

  The natural ground reinforcement pipes are connected by screw connection. For example, in tunnel leading work or mirror reinforcement work, about 4 of the 3 m natural ground reinforcement pipes are screwed and drilled. As shown in FIG. 10, the screw connection between the natural ground reinforcing pipes is performed using a coupler 5 that is a threaded joint, or a male thread portion formed at one end of the first natural ground reinforcing pipe and This is done by directly screwing the female thread portion formed at the other end of the second ground reinforcement pipe, and the latter has also been proposed to ensure the strength of the screw joint (Patent Document 1, 2).

JP 2004-332242 A JP 2012-188837 A

  By the way, in the double pipe drilling method as described above, the striking force P and the rotational force R of the drilling are transmitted only to the drilling bit 3, and the natural ground reinforcing pipes 1a to 1c and the like are sequentially drawn or pushed. However, in reality, vibration due to the striking force P or the rotational force R is transmitted to the ground reinforcement pipes 1a to 1c and the like.

  In this case, increasing the strength of the threaded portion of the natural ground reinforcement pipe and the threaded portion of the coupler may result in the separation of the coupler due to the crushing of the thread due to the vibration of the striking force P or the disengagement of the screw between the natural ground reinforcement pipes. Although it is possible to prevent this, it is difficult to prevent the screw connection between the coupler and the ground reinforcement pipe or the screw connection between the ground reinforcement pipes from gradually loosening due to the vibration of the striking force P or the rotational force R.

  In general, the tightening direction of the threaded portion of the coupler or the like corresponds to the rotational direction of the drilling rod. Therefore, even if vibration due to the rotational force R is transmitted, the threaded coupling of the coupler or the like is rarely loosened. If the rock mass of the mountain is unstable, the screw connection may be reversed in the direction of loosening. Once the screw connection starts to loosen, it is urged by the vibration caused by the striking force P or the rotational force R to loosen and come off. If the screw connection is removed in the long hole, it is not possible to remove and re-install the ground reinforcement pipe from which the screw connection has been released. It becomes difficult.

  The present invention is proposed in view of the above problems, and the screw connection between the cylindrical connecting member and the ground reinforcement pipe such as the screw connection between the coupler and the ground reinforcement pipe or the thread connection between the ground reinforcement pipes is loosened and released. An object of the present invention is to provide a coupling structure for a natural ground reinforcement pipe, a coupler, and a natural ground reinforcement pipe that can reliably prevent this and improve the reliability of the construction of the natural ground reinforcement.

In the connection structure of the natural ground reinforcement pipe according to the present invention, a male thread portion is provided at at least one end of the natural ground reinforcement pipe, and the right thread portion and the left formed in another region in the longitudinal direction of the natural ground reinforcement pipe The male thread part is constituted by the thread part, the female thread part that is screwed to the male thread part is provided in the cylindrical connecting member, and the female thread part is composed of the overlap thread part formed by overlapping the right screw and the left thread. It is characterized by that.
According to this configuration, the right screw is tightened when a clockwise force is applied to the natural reinforcement pipe, and the left screw is tightened when a counterclockwise force is applied. Therefore, the screw connection between the cylindrical connecting member and the natural reinforcement pipe is performed. Will not be loosened gradually. Therefore, it is possible to reliably prevent the screw connection between the cylindrical connecting member and the natural ground reinforcement pipe from being loosened and disengaged, and to improve the reliability of the natural ground reinforcement construction.

In the connection structure of the natural ground reinforcement pipe of the present invention, the right screw portion and the left screw portion of the male screw portion are formed discontinuously, and the female screw portion is formed on the mouth side, and the double screw portion. It is comprised in the back | inner side of the said overlapping thread part and the right-handed thread part, left-handed thread part, or overlapping thread part formed discontinuously.
According to this configuration, even if the screw connection starts to loosen due to rotation, the disengagement state of the thread is released by the discontinuous part in the middle, and only the vibration due to impact or rotation engages with the opposite thread. And can not proceed. Therefore, it is possible to more reliably prevent the screw connection between the cylindrical connecting member and the natural ground reinforcing pipe from loosening and coming off.

The connection structure for ground reinforcement pipes according to the present invention is characterized in that the cylindrical connection member is a coupler.
According to this configuration, the screw connection between the natural ground reinforcement pipe and the coupler is loosened, and the coupler can be prevented from being detached from the natural ground reinforcement pipe. Further, since both ends of the natural ground reinforcement pipe can be made the same male threaded portion, it is possible to eliminate setting the wrong direction in the front-rear direction when placing the natural ground reinforcement pipe in the natural ground.

The connection structure of the natural ground reinforcement pipe of the present invention is such that the cylindrical connection member is another ground natural reinforcement pipe (second natural ground reinforcement pipe) having the same configuration as the natural ground reinforcement pipe (first natural ground reinforcement pipe). ).
According to this configuration, it is possible to connect the first ground reinforcing pipe and the second ground reinforcing pipe without using a coupler, the number of parts can be reduced, and screw coupling work to the coupler can be performed. The work process can be made more efficient.

A coupler according to the present invention is a coupler that is provided at an end of a natural ground reinforcing pipe and is screwed into a male screw portion including a right screw portion and a left screw portion formed in another region in the longitudinal direction. The female screw part screwed into the male screw part is constituted by an overlap screw part formed by overlapping a right screw and a left screw.
According to this configuration, the right screw is tightened when a clockwise force is applied to the ground reinforcement pipe, and the left screw is tightened when a counterclockwise force is applied. Therefore, the screw connection between the coupler and the ground reinforcement pipe is gradually loosened. You wo n’t be overwhelmed. Therefore, it is possible to reliably prevent the screw connection between the coupler and the natural ground reinforcing pipe from loosening and coming off, and to improve the reliability of the natural ground reinforcing construction. In addition, by using this coupler, both ends of the natural ground reinforcement pipe can be made the same male threaded portion, so that it is not necessary to set the natural ground reinforcing pipe in the wrong direction when placing the natural ground reinforcement pipe in the natural ground. be able to.

The natural ground reinforcement pipe of the present invention is provided with male screw portions each composed of a right screw portion and a left screw portion formed in different regions in the longitudinal direction at both ends, and the right screw and the left screw are provided. The male screw portion of one end is screwed and connected to the female screw portion of the coupler formed by the overlapping screw portion formed in an overlapping manner.
According to this configuration, the right screw is tightened when a clockwise force is applied to the ground reinforcement pipe, and the left screw is tightened when a counterclockwise force is applied. Therefore, the screw connection between the coupler and the ground reinforcement pipe is gradually loosened. You wo n’t be overwhelmed. Therefore, it is possible to reliably prevent the screw connection between the coupler and the natural ground reinforcing pipe from loosening and coming off, and to improve the reliability of the natural ground reinforcing construction. Further, since both ends of the natural ground reinforcement pipe can be made the same male threaded portion, it is possible to eliminate setting the wrong direction in the front-rear direction when placing the natural ground reinforcement pipe in the natural ground.

The natural ground reinforcement pipe of the present invention is provided with a male screw portion composed of a right screw portion and a left screw portion formed in another region in the longitudinal direction at one end portion, and a right end at the other end portion. An internal thread portion formed by an overlap screw portion formed by overlapping a screw and a left screw is provided.
According to this configuration, the right screw is tightened when a clockwise force is applied to the ground reinforcement pipe, and the left screw is tightened when a counterclockwise force is applied. Therefore, the first ground reinforcement pipe and the second ground are tightened. The screw connection of the mountain reinforcing pipe is not gradually loosened. Therefore, it is possible to reliably prevent the screw connection between the first natural ground reinforcement pipe and the second natural ground reinforcement pipe from being loosened and coming off, and to improve the reliability of the natural ground reinforcement construction. Further, it is possible to connect without using a coupler, the number of parts can be reduced, and the work of screw connection to the coupler can be eliminated, and the work process can be made efficient.

  According to the present invention, the screw connection between the tubular connecting member and the natural ground reinforcement pipe, such as the screw connection between the coupler and the natural ground reinforcement pipe or the thread connection between the natural ground reinforcement pipes, can be reliably prevented and released. The certainty of mountain reinforcement construction can be increased.

(A) is a front view which shows the natural ground reinforcement pipe and coupler in the connection structure of the natural ground reinforcement pipe of 1st Embodiment, (b) is a front view which shows the connection state of the natural ground reinforcement pipe and coupler. (A)-(c) is explanatory drawing which shows the connection procedure of the natural ground reinforcement pipe | tube and coupler in 1st Embodiment (a coupler is a cross section). (A)-(c) is explanatory drawing which shows the connection procedure of the natural ground reinforcement pipe and coupler in 1st Embodiment (a coupler and a 1st natural ground reinforcement pipe are cross sections). Longitudinal explanatory drawing which shows the state which is performing face reinforcement of the tunnel under construction using the connection structure of the natural ground reinforcement pipe of 1st Embodiment. The partial cross-section explanatory drawing which shows the state which is performing the face reinforcement of the tunnel under construction using the connection structure of the natural ground reinforcement pipe of 1st Embodiment. (A)-(c) is explanatory drawing which shows the connection procedure of the natural ground reinforcement pipe | tube and coupler in 2nd Embodiment (a coupler is a cross section). (A)-(c) is explanatory drawing which shows the connection procedure of the natural ground reinforcement pipe and coupler in 2nd Embodiment (a coupler and a 1st natural ground reinforcement pipe are cross sections). (A)-(c) is explanatory drawing which shows the connection procedure of the natural ground reinforcement pipe and coupler in 3rd Embodiment (a 2nd natural ground reinforcement pipe is a cross section). (A)-(c) is sectional explanatory drawing which shows the connection procedure of the natural ground reinforcement pipe | tube and coupler in 3rd Embodiment. The schematic diagram which shows the natural ground reinforcement pipe | tube in a drilling hole, a drilling rod, and a drilling bit.

[Connection structure of ground reinforcement pipe of the first embodiment]
The connection structure of the natural ground reinforcement pipe of 1st Embodiment by this invention is a connection structure of the coupler 20 which is the natural ground reinforcement pipes 10a and 10b and a cylindrical connection member, as shown in FIGS. 1-3. Each of the first natural ground reinforcing pipe 10a and the second natural ground reinforcing pipe 10b has a cylindrical main body 11, and a peripheral wall of the main body 11 is formed with a discharge hole 12 of a grout material at an interval. In addition, a male screw portion 13 is provided at each of both end portions.

  Each male screw portion 13 is composed of a right screw portion 131 and a left screw portion 132, and the right screw portion 131 and the left screw portion 132 in the male screw portion 13 are located in different regions in the longitudinal direction of the natural ground reinforcing pipes 10a and 10b. Is formed. In the male screw portion 13 of this example, a left screw portion 132 is formed on the mouth side of the ground reinforcement pipe 10a or 10b, and a non-screw portion 133 in which no screw portion is formed is provided on the inner side, and the non-screw portion 133 is provided. A right screw portion 131 is formed on the back side of the left screw portion 131, and the left screw portion 132 and the right screw portion 131 are formed discontinuously. In addition, in the male thread part 13, it is also possible to set it as the structure which provides a right-hand thread part in a mouth side, and a left-hand thread part in a back | inner side.

  The coupler 20 has a cylindrical shape and is provided with a female screw portion 21 on the inner peripheral surface, and female screw portions 21 and 21 are provided so that they can be screwed from both ends. The female screw portion 21 is composed of a double screw portion 211 formed by overlapping a right screw and a left screw, and the double screw portion 211 can be screwed with the male screw portion 13 of the natural ground reinforcement pipe 10a or 10b.

  For example, when the female screw portion 21 of the coupler 20 is screwed into the male screw portion 13 at the rear end portion of the first natural mountain reinforcing pipe 10a placed in the natural ground, the coupler 20 is rotated counterclockwise to overlap the screw portion 211. Are screwed into the left screw portion 132 of the male screw portion 13 (see FIG. 2A and FIG. 3A), and when the overlap screw portion 211 of the coupler 20 reaches the right screw portion 131, The coupler 20 is rotated to the right, and the right screw of the overlap screw portion 211 is screwed into the right screw portion 131 of the male screw portion 13 (see FIGS. 2B and 3B). Then, the female screw portion 21 closer to the front of the coupler 20 is screwed to substantially the whole of the male screw portion 13, and the coupler 20 that is a cylindrical connecting member is connected to the first natural ground reinforcing pipe 10a.

  Further, when the male thread portion 13 at the front end of the second natural ground reinforcement pipe 10b is screwed into the coupler 20 connected to the rear end of the first natural ground reinforcement pipe 10a, the second natural ground is The reinforcing pipe 10b is rotated counterclockwise, and the left thread 132 of the male thread 13 at the front end is screwed into the overlapping thread 211 of the female thread 21 near the rear of the coupler 20 (FIG. 2 (c), FIG. 3 ( c)), when the right thread 131 of the second natural ground reinforcement pipe 10b reaches the coupler 20, the second natural ground reinforcement pipe 10b is rotated to the right to rotate the right thread 131 of the male thread 13 at the front end. Is screwed into the overlapping screw portion 211 of the coupler 20. Then, substantially the entire male thread portion 13 of the second natural ground reinforcement pipe 10b is screwed into the female thread 21 on the rear side of the coupler 20, and the second natural ground reinforcement pipe 10b is connected to the coupler 20 which is a cylindrical connecting member. Connected.

  The connection reinforcing pipe 50 constituted by connecting the natural ground reinforcing pipe 10 (10a, 10b, etc.) and the coupler 20 of the first embodiment is used in, for example, the tip receiving work 61 and the mirror reinforcing work 62 shown in FIGS. Used. 4 and 5, 71 is a natural ground, 72 is a tunnel space, 73 is a face at the tip of the tunnel being dug, 74 is a next excavation area, and 75 is a next face. A drill jumbo 63 is arranged.

  The front receiving work 61 is arranged to reinforce an arch shape by arranging a long connecting reinforcing pipe 50 on a natural ground 71 at the upper front part of the face 73. For example, a support work that has already been set up in the immediate vicinity of the face 73. A pilot hole having a diameter larger than that of the connecting reinforcing pipe 50 is drilled at a predetermined elevation angle from the top end of the face 73 toward the front upper ground 71 at the front position 64, and a double pipe drilling is performed from the lower hole. According to the method, the long ground reinforcing pipe 50 is driven by making a hole in the natural ground 71 and simultaneously driving the ground natural reinforcing pipe 10 into the drilling hole while connecting with the coupler 20.

  In forming the drilling holes and placing the connecting reinforcing pipe 50, the ground reinforcing pipe 10 is disposed in the guide cell 631 of the drill jumbo 63, and the drilling rod 632 having a drilling bit attached to the tip thereof is reinforced. It is inserted into the pipe 10 and the rear end of the drilling rod 632 is connected to the rock drill 633. Further, a casing shoe is provided on the outer periphery of the drill bit, and the tip of the ground reinforcement pipe 10 is attached to the casing shoe (see FIG. 10).

  Then, the rotational force and the striking force are transmitted from the rock drill 633 to the drilling bit through the drilling rod 632, and the coupler 20 is sequentially applied to the pulled ground reinforcing pipe 10, and the next natural ground reinforcing pipe 10 is sequentially provided. Next, a long connecting reinforcing pipe 50 in which the natural ground reinforcing pipe 10 is connected via the coupler 20 is driven and placed on the natural ground 71. After that, a grout material is injected from the existing connection reinforcing pipe 50 to form a consolidated region 65 in the ground 71 around the connection reinforcing pipe 50.

  Further, the mirror reinforcing work 62 reinforces the ground ground 71 in front of the face 73 by arranging a long connecting reinforcing pipe 50 and, for example, mirror-sprayed concrete 76 applied to the face 73. From the above construction procedure, the long excavation area 74 is drilled in the next excavation region 74, and a long connecting reinforcement pipe 50 is connected by the coupler 20, and the connection is made. A consolidated region 65 is formed around the reinforcing tube 50.

  According to the connection structure of the natural ground reinforcement pipes of the first embodiment, the right screw is tightened when a clockwise force is applied to the natural rock reinforcement pipes 10a and 10b, and the left screw is tightened when a counterclockwise force is applied. The screw connection between the coupler 20 and the natural ground reinforcement pipes 10a and 10b is not gradually loosened, and the coupler 20 can be prevented from being detached from the natural ground reinforcement pipes 10a and 10b. Therefore, it is possible to reliably prevent the screw connection between the coupler 20 and the natural ground reinforcing pipes 10a and 10b from being loosened and coming off, and to improve the reliability of the natural ground reinforcing construction.

  In addition, since both ends of the natural ground reinforcement pipes 10a and 10b can be the same male threaded portions 13 and 13, when the natural ground reinforcement pipes 10a and 10b are driven into the natural ground, they are set in the wrong direction. Can be eliminated.

[Connecting structure of ground reinforcement pipe of the second embodiment]
As shown in FIGS. 6 and 7, the connection structure of the natural ground reinforcement pipe of the second embodiment according to the present invention is the same as the natural ground reinforcement pipes 10a and 10b of the first embodiment and the coupler 30 which is a cylindrical connection member. And a coupler 30 for connecting the first natural ground reinforcing pipe 10a and the second natural ground reinforcing pipe 10b is different from that of the first embodiment.

  The coupler 30 has a cylindrical shape and is provided with an internal thread portion 31 on the inner peripheral surface, and is provided with internal thread portions 31 and 31 that can be screwed from both ends. Each female screw portion 31 includes an overlap screw portion 311 formed by overlapping a right screw and a left screw, a non-thread portion 312 having no screw thread, and a left screw portion 313.

  The overlap screw portion 311 is formed on the mouth side of the coupler 30, the non-thread portion 312 is formed on the back side of the overlap screw portion 311, and the left screw portion 313 is formed on the back side of the non-screw portion 312. The part 311 and the left-hand thread part 313 on the back side are formed discontinuously. The female threaded portion 31 can be screwed into the male threaded portion 13 of the ground reinforcement pipe 10a or 10b, the left threaded portion 313 is the left threaded portion 132 of the male threaded portion 13, and the non-threaded portion 312 is the unthreaded portion of the male threaded portion 13. 133, the overlap screw portion 311 is screwed in substantially corresponding to the right screw portion 131 of the male screw portion 13, and the coupler 30 and the ground reinforcement pipe 10a or 10b are connected.

  For example, when the female screw portion 31 of the coupler 30 is screwed into the male screw portion 13 at the rear end portion of the first natural mountain reinforcing pipe 10a placed in the natural ground, the coupler 30 is rotated counterclockwise to overlap the screw portion 311. Are screwed into the left screw portion 132 of the male screw portion 13 (see FIGS. 6A and 7A), and when the overlap screw portion 311 of the coupler 30 reaches the right screw portion 131, The coupler 30 is rotated clockwise and the right screw of the overlap screw portion 311 is screwed into the right screw portion 131 of the male screw portion 13 (see FIGS. 6B and 7B). At this time, the left screw portion 313 of the coupler 30 advances into the left screw portion 132 while being screwed with the left screw portion 132 of the male screw portion 13. Then, the female screw portion 31 on the front side of the coupler 30 is screwed into substantially the entire male screw portion 13, and the coupler 30 as a cylindrical connecting member is connected to the first natural ground reinforcing pipe 10a.

  Further, when the male thread portion 13 at the front end of the second natural ground reinforcing pipe 10b is screwed into the coupler 30 connected to the rear end of the first natural ground reinforcing pipe 10a, the second natural ground is The reinforcing pipe 10b is rotated counterclockwise, and the left thread 132 of the male thread 13 at the front end is screwed into the overlapping thread 311 of the female thread 31 at the rear of the coupler 30 (FIG. 6C, FIG. 7). c)). Thereafter, when the right thread 131 of the second natural ground reinforcement pipe 10b reaches the coupler 30, the second natural ground reinforcement pipe 10b is rotated to the right to connect the right thread 131 of the male thread 13 at the front end to the coupler 30. Are screwed into the overlapping screw portion 311. At this time, the left threaded portion 132 of the second natural ground reinforcing pipe 10b advances into the left threaded portion 313 while being screwed into the left threaded portion 313 of the coupler 30. Then, substantially the entire male thread portion 13 of the second natural ground reinforcement pipe 10b is screwed to the female thread section 31 on the rear side of the coupler 30, and the second natural ground reinforcement pipe 10b is connected to the coupler 30 which is a cylindrical connecting member. Connected.

  In addition, in the internal thread part 31 of the coupler 30, a thread part provided on the back side from the non-thread part 312 is configured as a double thread part where the right screw and the left screw are overlapped, or a thread part provided on the back side from the non-screw part 312. When the right thread part is provided on the mouth side in the male thread part 13 of the natural ground reinforcement pipe 10, it can be configured as a right thread part.

  The connection reinforcing pipe configured by connecting the natural ground reinforcing pipe 10 (10a, 10b, etc.) and the coupler 30 according to the second embodiment is also used in the above-described front receiving work 61 and mirror reinforcing work 62, for example. In the same manner as the pipe 50, it is placed in the natural ground 71.

  According to the connection structure of the natural ground reinforcement pipe of the second embodiment, a corresponding effect can be obtained from the configuration corresponding to the first embodiment. Furthermore, even if the screw connection between the ground reinforcement pipes 10a and 10b and the coupler 30 starts to loosen due to rotation, the thread is disengaged by a discontinuous portion in the middle, and only vibration due to impact or rotation It will not be possible to advance by engaging the opposite thread. Therefore, it is possible to more reliably prevent the screw connection between the coupler 30 and the natural ground reinforcing pipes 10a and 10b from loosening and coming off.

[Connection structure of ground reinforcement pipe of the third embodiment]
As shown in FIGS. 8 and 9, the connection structure of the natural ground reinforcement pipe of the third embodiment according to the present invention comprises the first natural ground reinforcement pipe 40 and the second natural ground reinforcement pipe 40 having the same configuration. This is a connection structure that connects directly without using a coupler. The ground reinforcement pipe 40 has a cylindrical main body 41, and a grout discharge port (not shown) is formed in the peripheral wall of the main body 41 so as to be spaced from each other. 42 is provided, and a female screw portion 43 is provided at the other end.

  The male screw portion 42 has the same configuration as the male screw portion 13 of the first and second embodiments, and is constituted by a right screw portion 421 and a left screw portion 422. The right screw portion 421 and the left screw portion 422 in the male screw portion 42 are The ground reinforcement pipe 40 is formed in another region in the longitudinal direction. In the male threaded portion 42 of this example, a left threaded portion 422 is formed on the mouth side of one end of the natural ground reinforcement pipe 40, and a non-threaded portion 423 without a threaded portion is provided on the back side thereof. A right screw portion 421 is formed on the back side of the screw portion 423, and the left screw portion 422 and the right screw portion 421 are formed discontinuously.

  The female screw portion 43 includes an overlap screw portion 431 formed by overlapping a right screw and a left screw, a non-thread portion 432 having no thread, and a left screw portion 433. The overlap screw portion 431 is formed on the mouth side of the other end portion of the ground reinforcement pipe 40, the non-thread portion 432 is formed on the back side of the overlap screw portion 431, and the left screw portion 433 on the back side of the non-screw portion 432. Are formed, and the overlap screw portion 431 and the left screw portion 433 are formed discontinuously.

  The male thread portion 42 of the first natural ground reinforcement tube 40 and the female thread portion 43 of the second natural ground reinforcement tube 40 can be screwed together, and the left thread portion 422 of the male thread portion 42 is the left thread portion of the female thread portion 43. 433, the non-threaded portion 423 is screwed with the non-threaded portion 432, and the right-hand threaded portion 421 of the male threaded portion 42 is screwed in substantially corresponding to the overlapping threaded portion 431 of the female threaded portion 43. The natural ground reinforcement pipe 40 is connected.

  For example, when the female thread portion 43 at the front end of the second natural ground reinforcement tube 40 is screwed into the male thread portion 42 at the rear end portion of the first natural ground reinforcement tube 40 placed in the natural ground, The natural thread reinforcement pipe 40 is rotated counterclockwise and the overlap screw part 431 is screwed into the left thread part 422 of the first natural ground reinforcement pipe 40 (see FIGS. 8A and 9A). When the overlap screw portion 431 of the second natural ground reinforcement pipe 40 reaches the right screw portion 421 of the first natural ground reinforcement pipe 40, the second natural ground reinforcement pipe 40 is rotated to the right and the overlap screw portion 431 The right screw is screwed into the right screw portion 421 of the male screw portion 42 (see FIGS. 8B and 9B).

  At this time, the left thread portion 433 of the female thread portion 43 of the second natural ground reinforcement pipe 40 is screwed with the left thread portion 422 of the male thread portion 42 of the first natural ground reinforcement pipe 40. Proceed with screwing in. And the female thread part 43 of the 2nd natural ground reinforcement pipe 40 is screwed by the external thread part 42 of the 1st natural ground reinforcement pipe 40, and the 1st natural ground reinforcement pipe 40 is the 2nd cylindrical connection member. The natural ground reinforcement pipe 40 is connected (see FIG. 8C and FIG. 9C).

  In the female thread portion 43 of the second natural ground reinforcement pipe 40, the screw portion provided on the back side of the non-thread portion 432 is a double screw portion in which the right screw and the left screw are overlapped, or the deeper portion than the non-screw portion 432. When the right thread portion is provided on the mouth side of the male thread portion 42 of the first ground reinforcement pipe 40, the thread portion provided on the side can be configured as a right thread portion.

  The connection reinforcement pipe constituted by connecting the ground reinforcement pipes 40 of the third embodiment to each other is also used, for example, in the above-described front receiving work 61 and mirror reinforcement work 62. Driven to the mountain 71.

  According to the connection structure of the ground reinforcement pipe of the third embodiment, the corresponding effect can be obtained from the configuration corresponding to the first and second embodiments. Furthermore, even when the screw connection of the ground reinforcement pipes 40 and 40 starts to loosen due to rotation, the thread is disengaged by the discontinuous part in the middle, and the screw in the opposite direction is only affected by vibration due to impact or rotation. It becomes impossible to advance by engaging with the mountain, and it is possible to more reliably prevent the screw connection of the ground reinforcement pipes 40 and 40 from loosening and coming off. Furthermore, it becomes possible to connect the 1st natural ground reinforcement pipe 40 and the 2nd natural ground reinforcement pipe 40 which is another natural ground reinforcement pipe of the same structure, without using a coupler, and to reduce the number of parts. In addition, the work of screw connection to the coupler can be eliminated, and the work process can be made more efficient.

[Modifications of Embodiment, etc.]
In addition to each invention and each embodiment, the invention disclosed in this specification is specified by changing these partial configurations to other configurations disclosed in this specification within the applicable range, or these It includes those specified by adding other configurations disclosed in this specification to the configuration, or those obtained by deleting these partial configurations to the extent that partial effects can be obtained and specifying them as a superordinate concept. The following modifications are also included.

  For example, in the first to third embodiments, in the male threaded portions 13 and 42 of the natural ground reinforcing pipes 10 and 40, the non-threaded portion 133 having a predetermined length between the right threaded portions 131 and 421 and the left threaded portions 132 and 422, Although 423 is provided, a configuration in which the non-threaded portions 133 and 423 are not provided is also possible. Similarly, a configuration in which the non-threaded portion 312 of the coupler 30 is not provided, or a configuration in which the non-threaded portion 432 of the female threaded portion 43 of the natural ground reinforcement pipe 40 is not provided, can be appropriately combined. It is possible.

  The present invention can be used, for example, when connecting and placing a natural ground reinforcement pipe so as to add to a natural ground to be reinforced by a double pipe drilling method in a receiving work or a mirror reinforcement work.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c ... Natural ground reinforcement pipe 2 ... Casing shoe 3 ... Drilling bit 4a, 4b, 4c ... Drilling rod 5 ... Coupler 10, 10a, 10b ... Natural ground reinforcement pipe 11 ... Main body 12 ... Discharge hole 13 ... Male thread part 131 ... Right thread part 132 ... Left thread part 133 ... Non thread part 20 ... Coupler 21 ... Female thread part 211 ... Overlapping thread part 30 ... Coupler 31 ... Internal thread part 311 ... Multiple thread part 312 ... Non thread part 313 ... Left thread Numeral 40: Natural mountain reinforcement pipe 41 ... Main body 42 ... Male screw part 421 ... Right screw part 422 ... Left screw part 423 ... Non-screw part 43 ... Female screw part 431 ... Overlapped screw part 432 ... Non-screw part 433 ... Left screw part 50 ... Reinforcement pipe 61 ... Point receiving work 62 ... Mirror reinforcement work 63 ... Drill jumbo 631 ... Guide cell 632 ... Drilling rod 633 ... Rock drill 64 ... Supporting work 65 ... Consolidation area 71 ... Mountain 72 ... tunnel space 73 ... Face 74 ... next excavation area 75 ... concrete P ... striking force blowing next working face 76 ... mirror R ... rotational force

Claims (7)

A male thread portion is provided on at least one end of the ground reinforcement pipe,
The male screw portion is composed of a right screw portion and a left screw portion formed in another region in the longitudinal direction of the natural ground reinforcing pipe,
A female threaded portion that is threadedly engaged with the male threaded portion is provided on the cylindrical connecting member,
The internal thread portion is composed of an overlap screw portion formed by overlapping a right screw and a left screw. The right screw portion and the left screw portion of the male screw portion are formed discontinuously,
The female screw portion is composed of a lap screw portion formed on the mouth side, and a right screw portion, a left screw portion or a lap screw portion formed discontinuously with the lap screw portion on the back side of the lap screw portion. The connection structure of the natural ground reinforcement pipe according to claim 1 characterized by things.   3. The connection structure for a ground reinforcement pipe according to claim 1, wherein the cylindrical connection member is a coupler.   The connection structure of the natural ground reinforcement pipe according to claim 1 or 2, wherein the cylindrical connection member is another natural ground reinforcement pipe having the same configuration as the natural ground reinforcement pipe. A coupler that is provided at an end portion of the natural ground reinforcement pipe and is screwed into a male screw portion that is formed of a right screw portion and a left screw portion formed in another region in the longitudinal direction,
A coupler characterized in that the female screw portion screwed into the male screw portion is composed of a double screw portion formed by overlapping a right screw and a left screw. Both end portions are provided with male thread portions each composed of a right-hand thread portion and a left-hand thread portion formed in different regions in the longitudinal direction,
A ground reinforcing pipe characterized in that a male screw portion of one end is screwed and connected to a female screw portion of a coupler formed by overlapping a right screw and a left screw. One end is provided with a male screw portion composed of a right screw portion and a left screw portion formed in another region in the longitudinal direction,
A natural thread reinforcing pipe is characterized in that a female thread portion composed of a double thread portion formed by overlapping a right screw and a left screw is provided at the other end portion.

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