Injection distribution device and ground reinforcement method using the same

Abstract

To provide an injection distribution device that improves worker safety and reduces the number of workers, and a ground reinforcement method using the same. [Solution] This injection distribution device 1 is used in a construction method for reinforcing unexcavated ground in a tunnel 41 by infiltrating ground improvement material into cracks in the surrounding ground. This injection distribution device 1 includes a plurality of distribution units 2 arranged in parallel, each of which connects a plurality of injection hoses 7 that inject ground improvement material to a plurality of injection tubes 43, an injection unit 3 that connects a plurality of injection hoses 8 that are connected to the discharge ports of injection pumps 35A and 35B of the injection machine 1, a first drive unit 4 that moves the injection unit 3 in the arrangement direction P of the plurality of distribution units 2 to align it with the position of a predetermined distribution unit 2, and a second drive unit 5 that moves the injection unit 3 toward and away from the predetermined distribution unit 2 to connect and disconnect the two units 2, 3.

Description

[Technical Field]

[0001] The present invention relates to a method for reinforcing the natural ground during tunnel excavation. [Background technology]

[0002] When excavating a tunnel, a method known as long steel pipe forepiling is known in which, as shown in Figure 8, a long steel pipe 42 is cast into the ground in front of a tunnel 41, and a ground improvement material is injected from inside this long steel pipe 42 to improve the ground (see, for example, Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-75292 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional techniques, as shown in Figure 9, multiple injection tubes 43 are inserted into a steel pipe 42 and the ground improvement material is injected through each tube 43. The ground improvement material injected into the steel pipe 42 penetrates into voids and cracks in the ground through discharge holes 42a on the outer periphery of the steel pipe 42, reinforcing the ground. A check valve 44 is connected to the end of the tube 43, which is connected to the tip of an injection hose extending from an injection machine for the ground improvement material. The connection between the check valve and the tip of the injection hose had to be done manually, and after injection was completed, the worker had to move to the adjacent hole. Furthermore, because connecting each steel pipe to the injection hose required close proximity to the face, workers had to constantly wait at the face to work, which posed a risk of damage from falling rocks due to rock fall or collapse of the ground.

[0005] The present invention has been made to solve the above problems, and aims to provide an injection distribution device and a ground reinforcement method using the same, which improves worker safety and reduces the number of workers by eliminating the need for workers to constantly wait at the face to connect each steel pipe to the injection hose during injection work, and by mechanically moving each steel pipe and connecting the injection hose after injection is completed without relying on human power. [Means for solving the problem]

[0006] The present invention is as follows. 1. An injection distribution device used in a construction method in which a plurality of long steel pipes are cast into unexcavated ground in a tunnel, a plurality of injection tubes are inserted into the long steel pipes, a ground improvement material is injected into the plurality of 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, a plurality of distribution units arranged in parallel, each of which is connected to a plurality of injection hoses for injecting the ground improvement material, and each of which is connected to a plurality of injection tubes; an injection unit for connecting a plurality of injection hoses to the outlet of an injection pump of the injection machine; a first driving unit that moves the injection unit in the arrangement direction of the plurality of distribution units to align it with the position of a predetermined distribution unit; and a second drive unit that moves the injection unit in a direction toward and away from the predetermined dispensing unit to connect and disconnect the two units. 2. The injection dispensing device described in 1. above, characterized in that the first drive unit has a motor for moving the injection unit and a rod screw rotated by the motor. 3. The injection dispensing device described in item 1 above, wherein the second drive unit has an electric cylinder for moving the injection unit. 4. A construction method for reinforcing the ground by driving multiple long steel pipes into the unexcavated ground of a tunnel, inserting multiple injection tubes into the long steel pipes, injecting ground improvement material into the multiple 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 installing multiple distribution units in parallel, each connecting multiple injection hoses for injecting the ground improvement material to the multiple injection tubes, and moving the injection unit, which connects multiple injection hoses connected to the discharge port of the injection pump of the injection machine, using a first drive unit to align it with the position of a predetermined distribution unit, and moving the injection unit using a second drive unit to connect it to the predetermined distribution unit, thereby injecting the ground improvement material into the multiple injection tubes. [Effects of the Invention]

[0007] According to the present invention, workers no longer need to approach the face to connect and disconnect steel pipes and injection hoses or move between steel pipes, which was previously done manually, thereby improving worker safety and reducing the number of workers. [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] 1A and 1B are explanatory views of an injection distribution device according to an embodiment, in which (a) shows a side view and (b) shows a front view. [Figure 2] 1A and 1B are explanatory diagrams of a distribution unit constituting the injection distribution device, in which (a) is a side view and (b) is a front view. [Figure 3] 1A and 1B are explanatory diagrams of an injection unit constituting an injection distribution device, in which (a) is a side view and (b) is a front view. [Figure 4] FIG. 2 is a front view of the injection machine according to the embodiment. [Figure 5] 1 is an explanatory diagram of the ground reinforcement method according to the embodiment, in which (a) shows the state in which an injection tube is inserted into a cast steel pipe, (b) shows the state in which the injection tube is connected to the injection hose of the distribution unit, and (c) shows the state in which the injection hose of the injection machine is connected to the injection unit. [Figure 6]This is an explanatory diagram of the ground reinforcement method, where (a) shows the state in which the injection unit is aligned with the specified distribution unit, (b) shows the state in which the injection unit and distribution unit are spaced apart, and (c) shows the state in which the injection unit and distribution unit are connected and close together. [Figure 7] An explanatory diagram of the ground reinforcement method, where (a) shows the state in which ground improvement material is being injected into the injection tube of a steel pipe, and (b) shows the state in which ground improvement material is being injected into the injection tube of an adjacent steel pipe. [Figure 8] This is an explanatory diagram of a typical ground reinforcement method (steel pipe installation process), where (a) shows a longitudinal section along the tunnel axis direction, and (b) shows a cross section perpendicular to the tunnel axis direction. [Figure 9] FIG. 1 is an explanatory diagram of a general ground reinforcement method (the injection tube insertion process). 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 distribution device 1 according to this embodiment is used in a construction method for reinforcing unexcavated ground in a tunnel 41 by injecting a ground improvement material into cracks in the surrounding ground (see FIGS. 8 and 9). More specifically, the injection distribution device 1 is used in a construction method in which multiple long steel pipes 42 are installed in the unexcavated ground in a tunnel 41, multiple injection tubes 43 (three in FIG. 9) of different lengths are inserted into the long steel pipes 42, and the ground improvement material is injected into the multiple injection tubes 43, and the ground improvement material is then infiltrated into cracks in the surrounding ground through discharge holes 42a provided on the periphery of the long steel pipes 42, thereby reinforcing the ground. The rear end of the injection tube 43 is provided with a check valve 44 to which the tip of an injection hose 7 (described below) is connected. In this embodiment, examples of ground improvement materials include a two-part mixture curing type urethane-based improvement material consisting of a first chemical liquid (base agent) and a second chemical liquid (hardener) and a silica resin-based improvement material.

[0012] As shown in Figure 1, the injection distribution device 1 comprises a plurality of distribution units 2 arranged in parallel, each having a plurality of injection hoses 7 connected to a plurality of injection tubes 43 for injecting ground improvement material, an injection unit 3 connecting a plurality of injection hoses 8 which are connected to the outlets of the injection pumps 35A and 35B of the injection machine 31, a first drive unit 4 which moves the injection unit 3 in the arrangement direction P of the plurality of distribution units 2 to align it with the position of a predetermined distribution unit 2, and a second drive unit 5 which moves the injection unit 3 in a direction approaching and moving away from the predetermined distribution unit 2 to attach and detach (i.e., connect and disconnect) the two units 2 and 3.

[0013] The distribution units 2 are fixed in parallel to the frame 9 of the distribution device 1, and have connection parts 11 for connecting to the multiple injection hoses 7 and couplers 12 for connecting to the injection units 3 (see Figure 2). A plurality of connection parts 11 and couplers 12 (six in Figure 2) are provided to correspond to the first and second liquids of the ground improvement material to be injected into each injection tube 43 in one steel pipe 42. Note that, in this embodiment, an example is shown in which six distribution units 2 are provided to correspond to six steel pipes 42, but the number of distribution units 2 to be installed is not particularly limited as long as there is a plurality.

[0014] The injection units 3 are movably mounted in the arrangement direction P (left-right direction P) of the distribution units 2 and in the direction Q (front-back direction Q) in which they approach and move away from a specific distribution unit 2. A support 15 is movably mounted on the frame 9 of the distribution device 1 in the arrangement direction P. The support 15 has a threaded portion 15a that threadably engages with a rod screw 22 (described below), a mounting portion 15b on which an electric cylinder 27 (described below) is installed, and a rod 15c that connects the threaded portion 15a and the mounting portion 15b (see Figure 3). The injection unit 3 is movably mounted along the rod 15c and has a connector 17 that connects multiple injection hoses 8 that are connected to the outlets of the injection pumps 35A and 35B of the injection machine 31, and a coupler 18 that connects to the coupler 12 of the distribution unit 2. A plurality of connectors 17 and couplers 18 (six in Figure 3) are provided, corresponding to the first and second liquids of the ground improvement material to be injected into each injection tube 43 in one steel pipe 42.

[0015] The first drive unit 4 has a motor 21 for moving the injection unit 3 and a rod screw 22 rotated by the motor 21. The motor 21 is mounted on a frame 9, and the rod screw 22 is rotatably supported on the frame 9. A sprocket 24, which is connected to the motor 21 by a timing belt 23 or a chain, is connected to the rod screw 22, and the rotation of the motor 21 rotates the rod screw 22 via the sprocket 24, moving the injection unit 3 in the arrangement direction P of the distribution unit 2.

[0016] The second drive unit 5 has an electric cylinder 27 for moving the injection unit 3. The electric cylinder 27 has a main body 27a and a piston rod 27b that is extendable relative to the main body 27a, the main body 27a is attached to the support 15 (specifically, the installation portion 15b), and the tip of the piston rod 27b is attached to the injection unit 3. The extension of the piston rod 27b moves the injection unit 3 in a direction approaching the predetermined distribution unit 2, connecting the two units 2 and 3, while the contraction of the piston rod 27b moves the injection unit 3 in a direction away from the predetermined distribution unit 2, disconnecting the two units 2 and 3 (see Figures 6(b) and 6(c)).

[0017] As shown in Figure 4, the injection machine 31 includes a pump unit 32 for pumping the ground improvement material, a control unit 33 for controlling the pump unit 32 based on the injection conditions (e.g., injection amount, injection pressure, etc.) of the ground improvement material, and tanks 34A and 34B for supplying the ground improvement material to the pump unit 32. The pump unit 32 includes multiple pairs of injection pumps 35A and 35B (three pairs in Figure 4) for pumping and mixing the first and second liquids of the ground improvement material for each steel pipe 42. The supply port of the first liquid injection pump 35A is connected to tank 34A, into which the first liquid is fed, and the supply port of the second liquid injection pump 35B is connected to tank 34B, into which the second liquid is fed. In addition, injection hoses 8 are connected to the discharge ports of the first and second liquid injection pumps 35A and 35B.

[0018] Next, a ground reinforcement method using the injection distribution device 1 configured as described above will be described. Steel pipes 42 are driven into the ground by a known method, and injection tubes 43 are inserted into the steel pipes 42 (see FIG. 5(a)). Next, injection hoses 7 connected to the distribution unit 2 are attached to the injection tubes 43 of the multiple steel pipes 42 (injection holes) (see FIG. 5(b)). Next, injection hoses 8 connected to the respective outlets of the injection pumps 35A and 35B for the first and second liquids of the injection machine 31 are connected to the injection unit 3 (see FIG. 5(c)). At this time, the cylinder 27 of the injection unit 3 is in a retracted state and is not connected to the distribution unit 2. Note that the order of connecting the injection hose 7 to the injection tube 43, the injection hose 7 to the distribution unit 2, and the injection hose 8 to the injection unit 3 does not matter.

[0019] Then, the motor 21 of the distribution device 1 is driven to move the injection unit 3 to the position of the specified distribution unit 2 (see Figure 6(a)). However, if the injection unit 3 is already aligned with the position of the specified distribution unit 2, there is no need to move the injection unit 3. Next, the cylinder 27 of the injection unit 3 is extended to connect the injection unit 3 to the distribution unit 2 (see Figures 6(b) and 6(c)). Next, the injection machine 31 is operated to inject the ground improvement material into each injection tube 43 of the steel pipe 42 (injection hole) via the injection unit 3 and the distribution unit 2 (see Figure 7(a)). When a predetermined end condition is reached, the injection is terminated, and the cylinder 27 of the injection unit 3 is retracted to separate the injection unit 3 from the distribution unit 2. Then, the motor 21 of the distribution device 1 is driven again to move the injection unit 3 to the position of the adjacent distribution unit 2. The above process is then repeated to inject the ground improvement material into each injection tube 43 of the adjacent steel pipe 42 (injection hole) via the injection unit 3 and the distribution unit 2 (see Figure 7(b)). The motor 21 and cylinder 27 of the distribution device 1 are driven by a switch box 29 (see FIG. 1) installed in the distribution device 1. However, the switch box 29 may be wired or wireless, such as a tablet.

[0020] As described above, the injection distribution device 1 of this embodiment includes multiple distribution units 2 arranged in parallel, each connected to multiple injection hoses 7 for injecting ground improvement material into multiple injection tubes 43; an injection unit 3 connected to multiple injection hoses 8, which are connected to the outlets of injection pumps 35A and 35B of the injection machine 31; a first drive unit 4 that moves the injection unit 3 in the arrangement direction P of the multiple distribution units 2 to align it with a predetermined distribution unit 2; and a second drive unit 5 that moves the injection unit 3 toward and away from a predetermined distribution unit 2 to connect and disconnect the two units 2 and 3. This eliminates the need for workers to approach the face to connect and disconnect the steel pipes 42 and injection hoses 7 or to move between the steel pipes 42, which was previously done manually, thereby improving the safety of the injection work. Furthermore, the worker operating the injection machine 31 can mechanically switch the injection hoses 7 to be injected into each steel pipe 42 using a switch box 29 at hand, thereby reducing the number of workers required.

[0021] Furthermore, in the injection dispensing device 1 of this embodiment, the first driving unit 4 has a motor 21 for moving the injection unit 3 and a rod screw 22 rotated by the motor 21. This allows the first driving unit 4 to align the injection unit 3 and the dispensing unit 2 more accurately and smoothly.

[0022] Furthermore, in the injection dispensing device 1 of this embodiment, the second drive unit 5 has an electric cylinder 27 for moving the injection unit 3. This allows the second drive unit 5 to more accurately and smoothly connect and disconnect the injection unit 3 and the dispensing unit 2.

[0023] Furthermore, according to the ground reinforcement method of this embodiment, multiple distribution units 2 are installed in parallel, each connecting multiple injection hoses 7 for injecting ground improvement material to multiple injection tubes 43. The injection unit 3, which connects multiple injection hoses 8 connected to the discharge ports of the injection pumps 35A and 35B of the injection machine 31, is moved by the first drive unit 4 to the position of a predetermined distribution unit 2, and the injection unit 3 is moved by the second drive unit 5 to connect to the predetermined distribution unit 2, thereby injecting the ground improvement material into the multiple injection tubes 43. This eliminates the need for workers to approach the face to connect and disconnect the injection hoses 7 to the steel pipes 42 or to move between the steel pipes 42, which was previously done manually, thereby improving the safety of the injection work. Furthermore, the worker operating the injection machine 31 can mechanically switch the injection hoses 7 to be injected into each steel pipe 42 using the switch box 29 at hand, thereby reducing the number of workers required.

[0024] It should be noted that the present invention is not limited to the embodiments, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in the above embodiment, an example is given in which one injection distribution device 1 is installed in the tunnel 41, but the present invention is not limited to this, and for example, a plurality of injection distribution devices 1 may be installed in the tunnel 41. For example, the injection distribution devices 1 may be installed in multiple tiers, one above the other, or multiple injection distribution devices 1 may be installed side by side, front to back or left to right.

[0025] In the above embodiment, the first drive unit 4 is operated by the motor 21, but is not limited to this and may be operated by, for example, an electric cylinder or a fluid cylinder. Furthermore, the first drive unit 4 may rotate the rod screw 22 by a gear instead of the timing belt 23 or a chain. In the above embodiment, the second drive unit 5 is operated by the electric cylinder 27, but is not limited to this and may be operated by, for example, a fluid cylinder or a motor.

[0026] Furthermore, in the above embodiment, a two-component mixed hardening type ground improvement material is exemplified, but the present invention is not limited to this, and one-component type ground improvement materials such as cement milk and mortar may also be used.

[0027] 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]

[0028] The present invention is widely used as a technique for injecting ground improvement materials in advance ground reinforcement methods during tunnel excavation. [Explanation of symbols]

[0029] 1; Injection distribution device 2; Distribution unit 3; Injection unit 4; First drive unit 5; second drive unit 7, 8; injection hose 21; Motor 22; Rod screw 27; Electric cylinder 31; Injection machine 41; Tunnel 42; Long steel pipe 43; Injection tube P; Arrangement direction of distribution unit

Claims

1. An injection distribution device used in a construction method in which a plurality of long steel pipes are installed in unexcavated ground of a tunnel, a plurality of injection tubes are inserted into the long steel pipes, a ground improvement material is injected into the plurality of 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, a plurality of distribution units arranged in parallel, each of which is connected to a plurality of injection hoses for injecting the ground improvement material; an injection unit for connecting a plurality of injection hoses to the outlet of an injection pump of the injection machine; a first driving unit that moves the injection unit in the arrangement direction of the plurality of distribution units to align it with the position of a predetermined distribution unit; and a second drive unit for moving the injection unit in a direction toward and away from the predetermined dispensing unit to connect and disconnect both units.

2. 2. The injection dispensing device of claim 1, wherein the first drive unit comprises a motor for moving the injection unit and a rod screw rotated by the motor.

3. 2. The injection dispensing device according to claim 1, wherein the second drive unit comprises an electric cylinder for moving the injection unit.

4. A construction method for reinforcing the ground by driving a plurality of long steel pipes into unexcavated ground in a tunnel, inserting a plurality of injection tubes into the long steel pipes, injecting ground improvement material into the plurality of 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 installing multiple distribution units in parallel to the multiple injection tubes, each connecting multiple injection hoses that inject the ground improvement material, and moving the injection unit, which connects multiple injection hoses that are connected to the discharge port of the injection pump of the injection machine, using a first drive unit to align it with the position of a predetermined distribution unit, and moving the injection unit using a second drive unit to connect it to the predetermined distribution unit, thereby injecting the ground improvement material into the multiple injection tubes.

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