Connection tool and connection method for long steel pipe

Abstract

To provide a connection tool and a connection method for long steel pipes that enable the connection of steel pipes without relying on manual labor.SOLUTION: A plurality of long steel pipes 3 is installed into the unexcavated ground of a tunnel 2. The long steel pipes are formed by connecting ends of a plurality of steel pipes 3a by threaded coupling. A connection tool 1 for long steel pipes is used in a method for impregnating ground improvement materials into cracks in the surrounding ground through a discharge hole 4 provided on an outer periphery of the long steel pipe to reinforce the ground. The connection tool is provided with a plurality of rollers 11 installed at a tip of a guide cell 22 of a drill jumbo 21 and supporting one end of the steel pipe 3a while rotating the steel pipe 3a.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to preliminary ground reinforcement work during tunnel excavation. [Background technology]

[0002] During tunnel excavation, as shown in Figure 8, a long steel pipe 3 is cast into the ground ahead of the tunnel 2, and ground improvement material is injected into cracks in the surrounding ground from discharge holes provided on the periphery of the long steel pipe 3 to reinforce the ground. This is known as long steel pipe forepiling (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-075292 Summary of the Invention [Problem to be solved by the invention]

[0004] A long steel pipe 3 (e.g., 12 m in total length) is generally constructed by connecting the ends of multiple (e.g., four) steel pipes (e.g., 3 m in total length) by screwing them together. In the prior art, as shown in Fig. 9, a female thread 6 is formed at the tip of a steel pipe 3a and a male thread 7 is formed at the rear end. Each steel pipe 3a is connected by manually rotating the steel pipe 3a to be connected to the steel pipe 3a cast into the natural ground. However, this method places a heavy burden on workers because heavy steel pipes 3a (e.g., 50 kg) must be rotated manually. Furthermore, because workers must approach very close to the tunnel face when connecting the steel pipes 3a, there is a risk of damage from falling rocks due to a collapse or landslide of the natural ground.

[0005] The present invention has been made to solve the above problems, and aims to provide a connecting device and connecting method for long steel pipes that allows steel pipes to be connected without relying on human power. [Means for solving the problem]

[0006] The present invention is as follows. 1. A connecting device for long steel pipes used in a construction method in which multiple long steel pipes are cast into unexcavated ground in a tunnel, the long steel pipes being formed by connecting the ends of multiple steel pipes by screwing them together, and ground improvement material is allowed to penetrate into cracks in the surrounding ground from discharge holes provided on the outer periphery of the long steel pipes to reinforce the ground, A connecting device for long steel pipes, characterized by being installed at the tip of a guide cell of a drill jumbo and having a plurality of rollers that support one end of the steel pipe and rotate the steel pipe. 2. The long steel pipe connecting device described in 1 above, characterized in that the rollers are driven by a motor. 3. A method for connecting long steel pipes that are cast into unexcavated ground in a tunnel and have the ends of multiple steel pipes connected by screwing, and are used to penetrate ground improvement material into cracks in the surrounding ground to reinforce the ground, Attach a connecting device to the tip of the guide cell of the drill jumbo, The steel pipe is driven into the ground so that the male thread portion provided at the rear end of the steel pipe is exposed from the ground, The steel pipe to be connected is placed on the guide cell of the drill jumbo so that one end of the steel pipe to be connected is supported by a roller provided on the connecting device; Align the direction and angle of the installed steel pipe with the connecting steel pipe, The steel pipe to be connected is moved forward, and the female threaded portion provided at the tip of the steel pipe to be connected is covered with the male threaded portion of the installed steel pipe, A method for connecting long steel pipes, characterized in that a motor provided in the connecting device is driven to rotate the roller, thereby screwing the male threaded portion of the cast steel pipe into the female threaded portion of the connecting steel pipe. [Effects of the Invention]

[0007] According to the present invention, steel pipes can be connected without relying on human power, which reduces the burden on workers and eliminates the need for workers to get very close to the face, improving work safety. [Brief explanation of the drawings]

[0008] The present invention will be further described in the following detailed description, which provides non-limiting examples of exemplary embodiments according to the present invention, and with reference to the several figures mentioned, in which like reference numerals refer to like elements throughout the several views of the drawings. [Figure 1] FIG. 2 is a plan view of the connecting fixture for long steel pipes according to the embodiment. [Figure 2] FIG. 2 is a view taken along the arrow II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is an explanatory diagram of a jumbo drill according to the embodiment. [Figure 5] 1A and 1B are explanatory diagrams of a method for connecting long steel pipes according to an embodiment, in which (a) shows the state in which a connecting device is installed at the tip of the guide cell of a drill jumbo, (b) shows the state in which a steel pipe has been cast into the ground, and (c) shows the state in which a steel pipe to be connected to the connecting device is supported. [Figure 6] This is an explanatory diagram of how to connect long steel pipes. (a) shows the state where the direction and angle of the cast steel pipe and the steel pipe to be connected are aligned, (b) shows the state where the female threaded portion of the steel pipe to be connected is placed over the male threaded portion of the cast steel pipe, and (c) shows the state where the female threaded portion of the steel pipe to be connected is screwed onto the male threaded portion of the cast steel pipe. [Figure 7] FIG. 10 is an explanatory view of a steel pipe according to another embodiment. [Figure 8] FIG. 1 is an explanatory diagram of a general ground reinforcement method. [Figure 9] FIG. 1 is an explanatory diagram of a typical connection form of steel pipes. DETAILED DESCRIPTION OF THE INVENTION

[0009] The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of the embodiments of the present invention, with the aim of providing what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this regard, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, and the description, taken together with the drawings, will make clear to those skilled in the art how some forms of the present invention may be actually embodied.

[0010] Hereinafter, the present invention will be specifically described by way of embodiments with reference to the drawings.

[0011] The connecting device 1 for long steel pipes according to this embodiment is used in a construction method in which a plurality of long steel pipes 3 are cast into unexcavated ground in a tunnel 2, and a ground improvement material such as a urethane-, cement-, or water glass-based material is infiltrated into cracks in the surrounding ground through discharge holes 4 provided on the periphery of the long steel pipes 3, thereby reinforcing the ground (see FIGS. 8 and 9). A single long steel pipe 3 (e.g., 12 m in total length) is constructed by connecting the ends of multiple (e.g., four) steel pipes 3a (e.g., 3 m in total length) by screwing them together. Each steel pipe 3a has a female thread 6 at its leading end and a male thread 7 at its trailing end. The steel pipes 3a are connected by screwing the female thread 6 of the subsequent steel pipe 3a to the male thread 7 of the preceding steel pipe 3a cast into the ground.

[0012] The connecting device 1 is installed at the tip of a guide cell 22 of a known drill jumbo (face drilling machine) 21 (see Figure 4). The drill jumbo 21 has a drifter 23 mounted on the guide cell 22 so that it can move back and forth, and a drilling bit (not shown) attached to the tip of a rod 24, the rear end of which is connected to the drifter 23, and drilling is performed by connecting multiple rods 24 of a predetermined length. The rotational force and propulsive force of the drifter 23 are transmitted to the drilling bit via the rod 24, and the bedrock or ground is excavated while the steel pipe 3a is driven in. The guide cell 22 is mounted at the tip of an extendable boom 25.

[0013] As shown in Figures 1 to 3, the connector 1 is equipped with multiple (three in the figure) rubber rollers 11 that support one end (tip) of the steel pipe 3a and rotate the steel pipe 3a. Each roller 11 is arranged so that its axis is aligned with the longitudinal direction of the guide cell 22. Each roller 11 is also arranged so as to support the outer circumferential surface below the axis of the steel pipe 3a inserted into the insertion space S of the support plate 13, which will be described later. The material of the rollers 11 is not particularly limited, and they may be made of synthetic resin or metal as long as they can rotate the steel pipe 3a. Furthermore, it is preferable that the outer circumferential surface of the rollers 11 is formed with an anti-slip portion consisting of fine irregularities.

[0014] The connector 1 includes a pair of support plates 13 that are erected on a base 12 and face each other. Each support plate 13 has an insertion space S into which one end of a steel pipe 3a can be inserted from above. The insertion space S is formed by left and right side walls and an arc-shaped bottom wall that is larger than the outer diameter of the steel pipe 3a and is connected to each side wall. Specifically, each support plate 13 is formed in a generally U-shape in plan view. Each roller 11 is rotatably supported between the pair of support plates 13 so that a portion of it protrudes into the insertion space S. The materials for the base 12 and the support plates 13 are not particularly limited and may be made of, for example, synthetic resin, but are preferably made of metal from the standpoint of strength, etc. It is particularly preferable that the metal support plate 13 be welded to the metal base 12.

[0015] The rollers 11 are equipped with pulleys or gears 16 on the same axis and are connected to one another by a timing belt or chain 17 so that they rotate in the same direction. At least one of the rollers 11 is connected by the timing belt or chain 17 to the drive shaft of a motor 18 installed on the base 12. The drive of the motor 18 can be remotely controlled via wire or wireless.

[0016] In this embodiment, the connecting device 1 is illustrated as having three rollers 11, but the present invention is not limited to this, and a connecting device 1 having, for example, two or four or more rollers 11 may be used. Furthermore, the driving force of the motor 18 may be transmitted to all of the plurality of rollers 11, or the driving force of the motor 18 may be transmitted to only some of the plurality of rollers 11.

[0017] Next, we will explain the method for connecting long steel pipes 3 using the connecting device 1 configured as described above. The connecting device 1 is attached to the tip of the guide cell 22 of the drill jumbo 21 (see Figure 5(a)). Next, a steel pipe 3a is driven into the natural ground using a known method (see Figure 5(b)). The male thread portion 7 at the rear end of this driven steel pipe (leading steel pipe) 3a is exposed from the natural ground. Next, the steel pipe 3a to be connected (following steel pipe) is placed on the guide cell 22 so that the tip of the steel pipe 3a to be connected is supported on the rollers 11 of the connecting device 1 (see Figure 5(c)).

[0018] After that, the direction and angle of the cast steel pipe 3a and the steel pipe 3a to be connected are aligned (see Figure 6(a)). This alignment of direction and angle can be performed using a direction control method installed on the drill jumbo 21 or a known direction control method using a laser. Next, the connecting steel pipe 3a is moved forward by advancing the drifter 23, and the female thread portion 6 of the steel pipe 3a to be connected is placed over the male thread portion 7 of the cast steel pipe 3a (see Figure 6(b)). Next, the motor 18 of the connecting device 1 is driven to rotate the roller 11, and the male thread portion 7 of the cast steel pipe 3a is screwed into the female thread portion 6 of the connecting steel pipe 3a (see Figure 6(c)). After the two steel pipes 3a are connected, the connected steel pipe 3a is driven. Then, by repeating the above-mentioned process, a long steel pipe 3 to which multiple steel pipes 3a are connected is driven into the natural ground.

[0019] As described above, the long steel pipe connecting device 1 of this embodiment is installed at the tip of the guide cell 22 of the drill jumbo 21 and includes multiple rollers 11 that support one end of the steel pipe 3a and rotate the steel pipe 3a. This allows the connecting device 1 to rotate the steel pipe 3a to be connected to the steel pipe 3a driven into the ground, thereby threading the two steel pipes 3a together, eliminating the need for workers to work close to the tunnel face. Furthermore, the rollers 11 are driven by a motor 18, eliminating the need for manual labor. Furthermore, because the rollers 11 are rotatably supported between a pair of support plates 13, the tip of the steel pipe 3a to be connected can be stably supported on the rollers 11.

[0020] It should be noted that the present invention is not limited to the above embodiment, and various modifications within the scope of the present invention are possible depending on the purpose and application. That is, in the above embodiment, the steel pipes 3a are threaded together with parallel thread portions 6, 7, but the present invention is not limited to this. For example, as shown in Figure 7, the steel pipes 3a may be threaded together with tapered thread portions 6, 7. According to this embodiment, the female thread portion 6 of the connecting steel pipe 3a can be easily fitted over the male thread portion 7 of the cast steel pipe 3a.

[0021] Furthermore, in the above embodiment, an example is given of a configuration in which the connecting steel pipe 3a is moved forward by the advancement of the drifter 23, thereby aligning each of the threaded portions 6, 7, but this is not limited to this, and a configuration in which the connecting steel pipe 3a is moved forward together with the guide cell 22 by, for example, the extension and retraction movement of the boom 25, thereby aligning each of the threaded portions 6, 7, may also be adopted.

[0022] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the claims of the present invention. [Industrial Applicability]

[0023] The present invention is widely used as a technique for connecting steel pipes in advance ground reinforcement methods during tunnel excavation. [Explanation of symbols]

[0024] 1. Long steel pipe connection device 2. Tunnel 3;Long steel pipe 3a;Steel pipe 4; Discharge hole 6; Female thread 7; Male thread portion 11; Roller 18;Motor 21;Jumbo Drill 22; Guide cell

Claims

1. A connecting device for long steel pipes used in a construction method in which a plurality of long steel pipes are cast into unexcavated ground in a tunnel, the long steel pipes being formed by connecting the ends of the plurality of steel pipes by screwing them together, and ground improvement material is allowed to penetrate into cracks in the surrounding ground from discharge holes provided on the outer periphery of the long steel pipes, thereby reinforcing the ground. A connecting device for long steel pipes, characterized by being installed at the tip of a guide cell of a drill jumbo and having a plurality of rollers that support one end of the steel pipe and rotate the steel pipe.

2. 2. The long steel pipe connecting device according to claim 1, wherein the rollers are driven by a motor.

3. A method for connecting long steel pipes, which are installed in multiple locations in unexcavated ground in a tunnel and have the ends of multiple steel pipes connected by screwing, is used to infiltrate ground improvement material into cracks in the surrounding ground and reinforce the ground, Attach a connecting device to the tip of the guide cell of the drill jumbo, The steel pipe is driven into the ground so that the male thread portion provided at the rear end of the steel pipe is exposed from the ground, The steel pipe to be connected is placed on the guide cell of the drill jumbo so that one end of the steel pipe to be connected is supported by a roller provided on the connecting device; Align the direction and angle of the installed steel pipe with the connecting steel pipe, The steel pipe to be connected is moved forward, and the female threaded portion provided at the tip of the steel pipe to be connected is covered with the male threaded portion of the installed steel pipe, A method for connecting long steel pipes, characterized in that a motor provided in the connecting device is driven to rotate the roller, thereby screwing the male threaded portion of the cast steel pipe into the female threaded portion of the connecting steel pipe.

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