Injection jig and ground reinforcement method with use of the jig

Abstract

To provide an injection jig and a ground reinforcement method, which enable connecting the tips of injection hoses to injection tubes without relying on manpower.SOLUTION: An injection jig 1 is used in a construction method to reinforce a ground by penetrating ground-improvement material into cracks in the surrounding natural ground, comprising a connection unit 11 that connects first injection pipes 7 connected to check valves 5 provided at the tips of injection tubes 4 with second injection pipes 15 provided for supplying ground-improvement material.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] When excavating a tunnel, a method known as long steel pipe forepiling is known in which long steel pipes are cast into the ground ahead of the tunnel and ground improvement material is injected into the long steel pipes to improve the ground (see Patent Document 1, etc.). [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] In the above-mentioned conventional technology, multiple injection tubes are inserted into the steel pipe during injection, and the ground improvement material is injected from each tube. The ground improvement material injected into the steel pipe penetrates into voids and cracks in the ground through discharge holes on the outer periphery of the steel pipe, reinforcing the ground. A check valve is connected to the end of this tube, which is connected to the tip of an injection hose extending from an injection machine for the ground improvement material. The check valve is exposed at the end of the steel pipe, and the connection between the check valve and the tip of the injection hose had to be done manually. Furthermore, since this connection required workers to get very close to the face, there was a risk of damage from falling rocks due to a collapse or landslide of the ground.

[0005] The present invention has been made to solve the above problems, and aims to provide an injection jig and a ground reinforcement method that enable the connection of the tip of the injection tube and the injection hose without relying on human power. [Means for solving the problem]

[0006] The present invention is as follows. 1. An injection jig used in a construction method in which a plurality of long steel pipes are cast into unexcavated ground in a tunnel, injection tubes are inserted into the long steel pipes, ground improvement material is injected into the injection tubes, and the 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, An injection jig characterized by comprising a connection unit that connects a first injection pipe that connects to a check valve provided at the end of the injection tube and a second injection pipe that supplies the ground improvement material. 2. The injection jig described in 1 above, characterized in that the connection unit comprises the second injection pipe that connects to an injection hose extending from an injection machine that supplies the ground improvement material, and a hydraulically or pneumatically operated cylinder that is connected to the second injection pipe and moves the second injection pipe in the forward and backward directions. 3. The injection jig described in 1 above, characterized in that the check valve provided at the end of the injection tube is located inside the long steel pipe. 4. A construction method in which multiple long steel pipes are cast into the unexcavated ground of a tunnel, injection tubes are inserted into the long steel pipes, ground improvement material is injected into the injection tubes, and the ground improvement material is allowed to penetrate into cracks in the surrounding ground through discharge holes provided on the outer periphery of the long steel pipes to reinforce the ground, A ground reinforcement method characterized by connecting a connection part provided on a connection unit to the end part of the long steel pipe, moving the second injection pipe provided on the connection unit forward by a drive part installed on the connection unit to connect it to a first injection pipe connected to a check valve provided at the end of the injection tube, and injecting the ground improvement material into the injection tube through the first injection pipe and the check valve. [Effects of the Invention]

[0007] According to the present invention, the tip of the injection tube and the injection hose can be connected and disconnected without relying on human power, so there is no need for workers to get very close to the face, improving the safety of the injection work. In addition, since there is no need for workers to connect and disconnect the tip of the injection tube and the injection hose, labor savings are achieved in the injection work. [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] 1 is a plan view, with a portion thereof cut away, of an injection jig (connection unit) according to an embodiment. [Figure 2] 2A and 2B are explanatory diagrams of a connection unit, in which FIG. 2A shows a view seen from an arrow A in FIG. 1, and FIG. 2B shows a view seen from an arrow B in FIG. [Figure 3] FIG. 2 is a cross-sectional view of a steel pipe (with an injection tube inserted) according to the embodiment. [Figure 4] FIG. 4 is an enlarged view of FIG. 3 taken along an arrow A. [Figure 5] 1 is an explanatory diagram of a natural ground reinforcement method according to an embodiment, showing a state in which an injection tube is inserted into a steel pipe. [Figure 6] This is an explanatory diagram of the ground reinforcement method, showing the connection unit installed in the basket of a drill jumbo. [Figure 7] An explanatory diagram of the ground reinforcement method, where (a) shows the state in which the steel pipe and connection unit are aligned, (b) shows the state in which the steel pipe and connection unit are connected, and (c) shows the state in which the first injection pipe and second injection pipe are connected. [Figure 8] This is an explanatory diagram of the ground reinforcement method, showing the state in which steel pipes have been cast into the ground. 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 injection jig 1 according to this embodiment is used in a construction method in which multiple long steel pipes 3 are cast into unexcavated ground in a tunnel 2, injection tubes 4 are inserted into the long steel pipes 3, and a ground improvement material such as a urethane-, cement-, or water glass-based material is injected into the injection tubes 4, allowing the material to penetrate into cracks in the surrounding ground through discharge holes 3a provided on the periphery of the long steel pipes 3, thereby reinforcing the ground (see Figures 3 and 8). Drilling holes in the ground and casting the steel pipes 3 are performed using a drill jumbo (excavation machine) 6. The drill jumbo 6 is equipped with a basket 6a at the tip of a boom 6b on which an operator can ride. The drill jumbo 6 also has an operator's cabin 6c for rotating and extending the boom 6b.

[0012] As shown in Figures 1 and 2, this injection jig 1 is equipped with a connection unit 11 that connects a first injection pipe 7 (see Figure 3) made of metal or resin that is connected to a known check valve 5 provided at the end of the injection tube 4, and a second injection pipe 15 made of metal or resin that supplies ground improvement material.

[0013] The connection unit 11 includes a second injection pipe 15 that connects to an injection hose 17 extending from a known injection machine 16 that supplies ground improvement material, and a hydraulically or pneumatically operated cylinder 13 (drive unit 13) that is connected to the second injection pipe 15 and moves the second injection pipe 15 back and forth. The second injection pipe 15 is connected to the injection hose 17 by a joint 18. The cylinder 13 is attached to a cylindrical support 12 made of metal or resin. The cylinder 13 is operated by a fluid supply from a fluid supply unit (not shown) such as a compressor or pump that is pre-installed in the drill jumbo 6. However, the cylinder 13 may also be operated by a fluid supply from a dedicated fluid supply unit installed separately from the drill jumbo 6.

[0014] In this embodiment, an example is shown in which each of the plurality of second injection pipes 15 is moved by a corresponding cylinder 13, but, for example, the plurality of second injection pipes 15 may be moved by one cylinder 13. Furthermore, the second injection pipes 15 may be moved by driving a motor (drive unit) instead of the cylinder 13.

[0015] A connection socket 14 (connection portion 14) is provided at the tip of the connection unit 11 to cover the end portion of the steel pipe 3. The tip portion of the connection socket 14 has an expanded diameter to facilitate alignment with the steel pipe 3. The connection socket 14 can be made of rubber, resin, or metal.

[0016] As shown in Figures 3 and 4, injection tube 4 to be inserted into steel pipe 3 has check valve 5 installed at its end, and check valve 5 is connected to first injection pipe 7. Injection tube 4 and first injection pipe 7 are fixed to the end of steel pipe 3 with rubber cap 8. The inner periphery of the tip of first injection pipe 7 is tapered to facilitate connection to second injection pipe 15. A sealant 9 is provided on the inner periphery of first injection pipe 7 to ensure watertightness between it and second injection pipe 15. However, sealant 9 may be provided on the outer periphery of second injection pipe 15 instead of or in addition to the inner periphery of first injection pipe 7.

[0017] The check valve 5 is located inside the steel pipe 3. The first injection pipe 7 is also located inside the steel pipe 3, with the axial end 3 of the first injection pipe 7 substantially coinciding with the axial end of the steel pipe. However, the axial end of the first injection pipe 7 may be located inside or outside the axial end of the steel pipe 3. The rubber cap 8 has a mark 21 (shown as a triangle in FIG. 4 ) on its surface. By aligning the mark 21 with a predetermined position (e.g., the upper end) of the steel pipe 3 and installing the rubber cap 8 inside the steel pipe 3, the multiple first injection pipes 7 can be positioned at predetermined positions around the axis of the steel pipe 3 (i.e., positions corresponding to the multiple second injection pipes 15 of the connection unit 11). The mark can be, for example, one or a combination of two or more colors, patterns, symbols, letters, etc.

[0018] A ground reinforcement method using the injection jig 1 configured as described above will be described below. A jumbo drill 6 is used to drive a steel pipe 3 into the ground using a known method (see Figure 8). Next, an injection tube 4 is inserted into the steel pipe 3 (see Figure 5). Then, check valves 5 at the ends of the multiple injection tubes 4 and a first injection pipe 7 connected to the check valve 5 are fixed to the end of the steel pipe 3 with a rubber cap 8.

[0019] Next, the connection unit 11 is installed on the boom 6b or basket 6a of the drill jumbo 6 (see Figure 6). After that, an operator operates the boom 6b or basket 6a inside the cabin 6c to align the positions of the steel pipe 3 and the connection unit 11 (specifically the connection socket 14) (see Figure 7(a)). For this alignment, a direction control method installed on the drill jumbo 6 or a known direction control method using a laser can be used.

[0020] Next, the boom 6b or basket 6a is operated to connect the steel pipe 3 to the connection unit 11 (specifically, the connection socket 14) (see Figure 7(b)). Next, the cylinder 13 of the connection unit 11 is operated to move the second injection pipe 15 inside the connection unit 11 forward and connect it to the first injection pipe 7 of the injection tube 4 (see Figure 7(c)). After that, the injection machine 16 is operated to inject the ground improvement material into the injection tube 4 through the injection hose 17, second injection pipe 15, first injection pipe 7, and check valve 5. Then, when a predetermined end condition is reached, the injection is stopped and the cylinder 13 of the connection unit 11 is operated to move the second injection pipe 15 inside the connection unit 11 backward.

[0021] As described above, the injection jig 1 of this embodiment includes a connection unit 11 that connects the first injection pipe 7, which connects to the check valve 5 provided at the end of the injection tube 4, and the second injection pipe 15, which supplies ground improvement material. The connection unit 11 includes a connection part 14 that connects to the end of the steel pipe 3 and a drive part 13 that moves the second injection pipe 15 in the forward and backward directions. Thus, by connecting the connection part 14 provided on the connection unit 11 to the end of the long steel pipe 3 and using the drive part 13 installed on the connection unit 11 to move the second injection pipe 15 provided on the connection unit 11 forward to connect it to the first injection pipe 7, which connects to the check valve 5 provided at the end of the injection tube 4, the ground improvement material can be injected into the injection tube 4 through the first injection pipe 7 and the check valve 5. In this way, the tip of the injection tube 4 and the injection hose 17 can be connected and disconnected without relying on human power, eliminating the need for workers to approach the face, improving the safety of the injection work. Furthermore, since no worker is required to connect or disconnect the tip of injection tube 4 and injection hose 17, labor savings are achieved in the injection work.

[0022] In this embodiment, the connection unit 11 also includes a second injection pipe 15 that connects to an injection hose 17 extending from an injection machine 16 that supplies ground improvement material, and a hydraulically or pneumatically operated cylinder 13 that is connected to the second injection pipe 15 and moves the second injection pipe 15 back and forth. This makes it easy to connect and disconnect the first injection pipe 7 and the second injection pipe 15.

[0023] Furthermore, in this embodiment, the check valve 5 provided at the end of the injection tube 4 is located inside the long steel pipe 3. This makes it easy to connect and disconnect the end of the steel pipe 3 and the connection part 14 of the connection unit 11. This also makes it possible to realize a construction site with a smart appearance.

[0024] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in the above-described embodiment, for example, as shown in Fig. 4, an identification portion 23 (shown as a triangle, square, or circle in the figure) indicating the appropriate correspondence between each support hole 8a of the rubber cap 8 and each first injection tube 7 of different lengths and colors may be provided on the surface of the rubber cap 8. The identification portion 23 can be, for example, one or a combination of two or more types of colors, patterns, symbols, letters, etc.

[0025] 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]

[0026] The present invention is widely used as a technique for connecting the tip of an injection tube and an injection hose for advance reinforcement of the ground during tunnel excavation. [Explanation of symbols]

[0027] 1. Injection jig 2. Tunnel 3; Long steel pipe 4; Injection tube 5; Check valve 7; First injection pipe 11; Connection unit 13; Cylinder (drive unit) 14; Connection socket (connection part) 15; Second injection pipe.

Claims

1. An injection jig used in a construction method in which a plurality of long steel pipes are cast into unexcavated ground in a tunnel, injection tubes are inserted into the long steel pipes, a ground improvement material is injected into the injection tubes, and the 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, An injection jig characterized by comprising a connection unit that connects a first injection pipe that connects to a check valve provided at the end of the injection tube and a second injection pipe that supplies the ground improvement material.

2. The injection jig described in claim 1, characterized in that the connection unit comprises the second injection pipe that connects to an injection hose extending from an injection machine that supplies the ground improvement material, and a hydraulically or pneumatically operated cylinder that is connected to the second injection pipe and moves the second injection pipe in the forward and backward directions.

3. 2. The injection jig according to claim 1, wherein the check valve provided at the end of the injection tube is located inside the long steel pipe.

4. A construction method for reinforcing the ground by driving a plurality of long steel pipes into unexcavated ground in a tunnel, inserting injection tubes into the long steel pipes, injecting ground improvement material into the injection tubes, and allowing the ground improvement material to penetrate into cracks in the surrounding ground through discharge holes provided on the outer periphery of the long steel pipes, A ground reinforcement method characterized by connecting a connection part provided on a connection unit to the end part of the long steel pipe, moving the second injection pipe provided on the connection unit forward by a drive part installed on the connection unit to connect it to a first injection pipe connected to a check valve provided at the end of the injection tube, and injecting the ground improvement material into the injection tube through the first injection pipe and the check valve.

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