Ultrasonic vibration liquid injection system and ultrasonic vibration liquid injection method

Abstract

To provide an ultrasonic vibration liquid injection system which enables simple and pinpoint liquid injection to prevent groundwater from gushing out at an arrival shaft in tunnel excavation work by a shield method.SOLUTION: A chemical liquid injection rod 20 has a shaft mounting bracket 30 fixed to a shaft wall 92, and a rod body 40 with a tip connected to the shaft mounting bracket. The rod body 40 can deliver a chemical liquid in which a base agent and a hardener are mixed, and is provided therein with an oscillator 47 that generates ultrasonic vibrations by an electric signal. The chemical liquid injection rod 20 injects the chemical liquid into an injection point GP while applying ultrasonic vibrations generated by the oscillator 47 to the chemical liquid and the ground. A chemical liquid supply device 50 supplies the base agent and the hardener to the chemical liquid injection rod 20. An ultrasonic oscillator 61 outputs an electric signal that causes the oscillator 47 to generate ultrasonic vibrations. An air supply device 620 supplies air to the chemical liquid injection rod 20 to cool the oscillator 47 when ultrasonic waves are generated.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ultrasonic vibration chemical solution injection system and an ultrasonic vibration chemical solution injection method.

Background Art

[0002] As disclosed in Patent Documents 1 and 2, a chemical solution injection device and method for injecting a chemical solution into the ground using ultrasonic vibration are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the prior art of Patent Documents 1 and 2, mainly for the purpose of injecting a chemical solution into a relatively wide range of soft ground, a method of penetrating an injection pipe into an existing groove or borehole dug from the ground into the ground is assumed. By applying ultrasonic vibration, the occurrence of split injection is avoided, and smooth and uniform penetration of the solidifying agent is realized.

[0005] On the other hand, in tunnel excavation work by the shield method, there is a risk that groundwater in the soil will flow into the shaft at the moment when the shield machine penetrates the arrival shaft. Therefore, it is required as a safety measure to inject a chemical solution into the surrounding ground to strengthen the ground and prevent the gushing of groundwater.

[0006] Conventionally, a large-scale construction method of injecting chemical solution into a bored hole drilled from the ground above a tunnel has been carried out by a specialized contractor. However, in order to permeate the chemical solution widely through the injection pipe penetrated into the bored hole, there was a concern that the chemical solution could not permeate to the target points around the planned penetration area, and it was impossible to surely prevent the gushing of groundwater. In addition, since it takes time to arrange for a specialized contractor and prepare for construction, there was a problem that the construction schedule was extended and the cost increased.

[0007] The present invention has been created in view of such points, and its object is to provide an ultrasonic vibration chemical solution injection system and an ultrasonic vibration chemical solution injection method that are simple and can inject chemical solution pinpointedly to prevent the gushing of groundwater in the access shaft for tunnel excavation work by the shield method.

Means for Solving the Problems

[0008] One aspect of the present invention is a chemical solution injection system for injecting a chemical solution for preventing the gushing of groundwater around the ground of the planned penetration area (92) using ultrasonic vibration prior to penetration into the access shaft (91) in tunnel excavation work by the shield method. This system includes a chemical solution injection rod (20), a chemical solution supply device (50), an ultrasonic oscillator (61), and an air supply device (620).

[0009] The chemical solution injection rod has a shaft attachment fitting (30) fixed to the shaft wall (92) and a rod body (40) whose tip is connected to the shaft attachment fitting. The rod body can send out a chemical solution in which a main agent and a curing agent are mixed, and a vibrator (47) that generates ultrasonic vibration by an electric signal is provided inside. The chemical solution injection rod injects the chemical solution into the injection point (GP) while applying the ultrasonic vibration generated by the vibrator to the chemical solution and the ground.

[0010] The chemical solution supply device supplies the main agent and the curing agent to the chemical solution injection rod respectively. The ultrasonic oscillator outputs an electric signal that generates ultrasonic vibration to the vibrator. The air supply device supplies air that cools the vibrator to the chemical solution injection rod when ultrasonic vibration is generated.

[0011] The rod body is formed with a main agent passage (441) and a hardener passage (442) through which the main agent and the hardener supplied from the chemical solution supply device are respectively sent toward a chemical solution mixing chamber (444) formed on the tip side, and an air passage (46) for introducing the air supplied from the air supply device around the vibrator, which are formed so as to be isolated from each other.

[0012] Preferably, the rod body is formed in a triple tube structure in which the main agent passage, the hardener passage, and the air passage are coaxial. Thereby, a compact and easily manufacturable structure is realized.

[0013] Also preferably, the air supply device includes an air compressor (62) that generates compressed air, an air dryer (63) that removes moisture in the compressed air, and a regulator (64) that regulates the compressed air from which the moisture has been removed and supplies it to the rod body. By removing the moisture in the compressed air, it is possible to prevent a short circuit due to moisture adhesion to the connection terminal portion of the vibrator. Also, by adjusting the supplied air pressure, it is possible to reduce variations in cooling performance.

[0014] Also preferably, an electric cable (66) that sends an electric signal from the ultrasonic oscillator to the vibrator is inserted inside an air tube (65) connected to the air outlet (451) of the rod body. Thereby, it is not necessary to separately provide an inlet for pulling in the electric cable in the rod body, and the wiring becomes simple. Also, it protects against damage to the coating of the electric cable. Also, the work of the air piping and the electric signal wiring can be performed at once. Furthermore, it is possible to prevent air leakage from the junction portion that is a concern when the electric cable is joined in the middle of the air path.

[0015] Another aspect of the present invention is a chemical solution injection method for injecting a chemical solution for preventing the gushing of groundwater around a planned penetration portion (93) from a chemical solution injection rod (20) using ultrasonic vibration prior to penetration into a shaft (91) in tunnel excavation work by the shield method. This method includes an installation step (S11), a mounting step (S12), a connection step (S13), and an injection step (S14).

[0016] In the installation process, a chemical solution supply device (50) that supplies the main agent and the curing agent to the chemical solution injection rod respectively, an ultrasonic oscillator (61) that outputs an electrical signal, and an air supply device (620) that supplies air to the chemical solution injection rod are installed. In the attachment process, the shaft pit attachment fitting (30) is fixed to the shaft pit wall (92).

[0017] In the connection process, the tip of the rod body (40) is connected to the shaft pit attachment fitting to form the chemical solution injection rod. The rod body is provided with a vibrator (47) inside that generates ultrasonic vibration by the electrical signal output by the ultrasonic oscillator.

[0018] In the injection process, with the chemical solution injection rod, the main agent and the curing agent supplied from the chemical solution supply device are mixed and sent out, and while cooling the vibrator with the air supplied from the air supply device, the ultrasonic vibration generated by the vibrator is applied to the chemical solution and the ground, and the chemical solution is injected into the injection point (GP).

[0019] In the system and construction method of the present invention, the chemical solution can be injected pinpoint to the injection points around the planned penetration area from the inside of the reached shaft pit. Since the chemical solution is effectively penetrated using ultrasonic vibration, the gushing of groundwater is more reliably prevented and the safety is improved. In addition, it is a simple construction method that only requires attaching the chemical solution injection rod to the injection point and does not require arranging a professional, so the construction time can be shortened and the cost can be reduced.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0021] <One Embodiment> The ultrasonic vibration chemical solution injection system and the ultrasonic vibration chemical solution injection method according to one embodiment of the present invention will be described with reference to the drawings. This system and method are a system and method for injecting a chemical solution for preventing the gushing of groundwater into the ground around the planned penetration area using ultrasonic vibration before penetrating into the arrival shaft in tunnel excavation work by the shield method.

[0022] Referring to FIGS. 1 to 8, the ultrasonic vibration chemical solution injection system of one embodiment will be described. FIG. 1 shows the overall configuration of the system. The shield machine 80 that has advanced underground is in a position immediately before penetrating into the arrival shaft 91. A steel cylindrical shaft wall 92 is embedded in the inner wall of the arrival shaft 91. If the shield machine 80 penetrates into the planned penetration area 93 of the arrival shaft 91 as it is, there is a risk that the groundwater in the soil will flow into the shaft at the moment of penetration. Therefore, it is required as a safety measure to inject a chemical solution into the surrounding ground 90 to strengthen the ground and prevent the gushing of groundwater.

[0023] Figure 1 schematically shows the components of the entire system and the wiring and piping connection system. For details of each component, refer to FIGS. 2 to 8 and the description will be given later. This ultrasonic vibration chemical solution injection system 100 includes a chemical solution injection rod 20, a chemical solution supply device 50, an ultrasonic oscillator 61, and an air supply device 620. In this embodiment, the ultrasonic oscillator 61 and the air supply device 620 are unitized as an ultrasonic oscillator unit 60.

[0024] The chemical solution injection rod 20 has a shaft sinking attachment fitting 30 and a rod body 40, and is held substantially horizontally in the shaft sinking 91 to be reached. The rod body 40 can deliver a chemical solution in which a main agent and a curing agent are mixed. Further, a vibrator 47 is provided inside the rod body 40. The chemical solution injection rod 20 injects the chemical solution into the injection point GP while applying ultrasonic vibration generated by the vibrator 47 to the chemical solution and the ground.

[0025] The chemical solution supply device 50 supplies the main agent and the curing agent to the chemical solution injection rod 20 respectively. The ultrasonic oscillator 61 outputs an electric signal that generates ultrasonic vibration to the vibrator 47. The air supply device 620 supplies air that cools the vibrator 47 when ultrasonic vibration is generated to the chemical solution injection rod 20.

[0026] FIG. 2 shows the appearance of the chemical solution injection rod 20. Hereinafter, in the description of the chemical solution injection rod 20, the side to which the shaft sinking attachment fitting 30 is connected (the left side in the figure) is referred to as the tip side, and the side opposite to the tip side (the right side in the figure) is referred to as the rear. The chemical solution injection rod 20 is configured by connecting a connecting portion 42 provided at the tip of the rod body 40 to the shaft sinking attachment fitting 30.

[0027] The shaft sinking attachment fitting 30 has a socket 32 welded to a flat steel 31, and a connector 32C is screwed and fixed to the socket 32. The shaft sinking attachment fitting 30 is fixed to the shaft sinking wall 92 by welding the flat steel 31 to the shaft sinking wall 92 (see FIG. 10). An opening 33 is formed in the central portion of the flat steel 31 so as to surround the injection point GP.

[0028] For example, the connector 32C is a camlock male, and the connecting part 42 is a camlock female. By inserting the connector 32C into the connecting part 42 and locking the lever 42L in a state where the male and female of the camlock are fitted, the shaft sinking attachment fitting 30 and the rod body 40 are connected (see Fig. 11).

[0029] The outer cylinder 411 appears on the outer appearance of the rod body 40. A main agent suction port 431 and a hardener suction port 432 are provided behind the rod body 40. Further behind the main agent suction port 431 and the hardener suction port 432, an air supply port 451 and an air exhaust port 452 are provided. At the central part of the rod body 40, a chain 49 with a ring for crane operation is attached so that two symmetrically located positions on the front and rear sides sandwiching the center of gravity can be lifted. While lifting using the chain 49 with a ring, the rod body 40 is connected to the shaft sinking attachment fitting 30 in a substantially horizontal state.

[0030] Figs. 3(a) and (b) schematically show cross-sections in the axial direction and the radial direction of the chemical solution injection rod 20. Also, Fig. 4 shows the flow of the chemical solution and air inside the chemical solution injection rod 20. Inside the rod body 40, a vibrator 47 that generates ultrasonic vibration by an electric signal is provided. The horn 473 at the tip of the vibrator 47 is positioned to face the opening 33.

[0031] Behind the vibrator 47, a chemical solution passage 44 through which the main agent and the hardener supplied from the chemical solution supply device 50 are sent toward the tip, and an air passage 46 that introduces the air supplied from the air supply device 620 around the vibrator 47 are formed separately from each other. The chemical solution passage 44 consists of a main agent passage 441, a hardener passage 442, and a chemical solution mixing chamber 444 formed on the tip side of the rod body 40. Behind the chemical solution mixing chamber 444, the main agent passage 441 and the hardener passage 442 are formed separately from each other.

[0032] Specifically, behind the chemical solution mixing chamber 444, three members, namely the outer cylinder 411, the middle cylinder 412, and the inner cylinder 413, are coaxially provided. The annular space between the outer cylinder 411 and the middle cylinder 412 forms the main agent passage 441, and the annular space between the middle cylinder 412 and the inner cylinder 413 forms the curing agent passage 442. The space inside the inner cylinder 413 forms the air passage 46. Thus, the rod body 40 of this embodiment is formed in a triple-tube structure with the main agent passage 441, the curing agent passage 442, and the air passage 46 being coaxial. As a result, a compact and easily manufacturable structure is realized.

[0033] As shown in FIG. 4, the main agent supplied from the chemical solution supply device 50 passes through the main agent passage 441 from the main agent suction port 431 and is sent toward the chemical solution mixing chamber 444. The curing agent supplied from the chemical solution supply device 50 passes through the curing agent passage 442 from the curing agent suction port 432 and is sent toward the chemical solution mixing chamber 444. The main agent and the curing agent merge and are mixed in the chemical solution mixing chamber 444. The mixed chemical solution (illustrated by cross-hatching) is injected from the opening 33 into the injection point GP.

[0034] Also, the air supplied from the air supply device 620 is introduced from the air supply port 451 through the air passage 46 around the vibrator 47 and discharged from the air exhaust port 452. By flowing air using the air tube 465 disposed in the air passage 46, in addition to cooling the vibrator 47, corrosion due to rust inside the chemical solution injection rod 20 can be prevented. Note that the illustration of the air tube 465 is omitted in FIGS. 3 and 6.

[0035] An enlarged view of the vibrator 47 is shown in FIG. 5. Also, FIG. 6 shows the state in which the vibrator 47 generates ultrasonic vibrations by the electrical signal output from the ultrasonic oscillator 61. The vibrator 47 has a substantially cylindrical shape and includes a main body 471, a flange portion 472, a horn 473, etc. The main body 471 is composed of a piezoelectric element or the like and vibrates by the electrical signal sent from the ultrasonic oscillator 61.

[0036] The horn 473 is provided on the tip side of the main body 471 with the flange portion 472 interposed therebetween. As shown in FIG. 6, the horn 473 amplifies the vibration of the main body 471 and radiates ultrasonic waves from the tip. The horn 473 radiates ultrasonic waves with a frequency of 28 kHz and an output of 10 W to 100 W toward the chemical solution and the ground, for example, in a cycle of ON for 30 seconds - OFF for 30 seconds. As described in Patent Documents 1 and 2, when ultrasonic vibration energy is applied to the particles and media contained in the chemical solution, and the soil particles, water, and air in the ground, the penetration and diffusion effect of the injected chemical solution is improved.

[0037] By the way, since the vibrator 47 generates heat when ultrasonic vibration occurs, cooling is required to maintain performance. However, Patent Documents 1 and 2 do not mention any problems regarding the heat generation of the vibrator at all. One of the features of the present embodiment is that a configuration for cooling the heat generated by the vibrator 47 during ultrasonic vibration generation is provided.

[0038] When ultrasonic vibration is generated, the air from the air supply device 620 is supplied to the vibrator 47 through the air passage 46 (see FIG. 4). An insulating layer 474 made of urethane resin mold is formed on the outer periphery of the rear part of the main body 471. Further, the connection terminal 475 connected to the electric cable 66 behind the main body 471 is covered with a shrink tube 476. The insulating layer 474 and the shrink tube 476 prevent a short circuit due to moisture adhesion in the cooling air. Furthermore, the shrink tube 476 prevents twisting and kinking of the core wire of the electric cable.

[0039] FIG. 7 shows a configuration example of the chemical solution supply device 50. The chemical solution supply device 50 includes a main agent mixer 511, a curing agent mixer 512, a chemical solution pump 53, and the like. The main agent mixer 511, the curing agent mixer 512, and the chemical solution pump 53 are connected by pump front hoses 521 and 522, respectively. The chemical solution pump 53 and the main agent suction port 431 and the curing agent suction port 432 of the rod main body 40 are connected by pump rear hoses 541 and 542, respectively.

[0040] The main agent mixer 511 and the curing agent mixer 512 stir the main agent and the curing agent stored in the tanks, respectively. The chemical liquid pump 53 sucks the main agent and the curing agent stirred by the mixers 511 and 512 and pumps them to the main agent suction port 431 and the curing agent suction port 432 of the rod body 40, respectively.

[0041] Fig. 8 shows a configuration example of the ultrasonic oscillator unit 60. The ultrasonic oscillator unit 60 is installed with the ultrasonic oscillator 61 and the air supply device 620 unitized on a common platform. The air supply device 620 includes an air compressor 62, a regulator 63, and an air dryer 64 in order from upstream to downstream. The ultrasonic oscillator 61 is supplied with an AC200V power supply, and the air compressor 62, the regulator 63, and the air dryer 64 are supplied with an AC100V power supply via a transformer.

[0042] The ultrasonic oscillator 61 outputs an electrical signal that generates ultrasonic vibrations in the vibrator 47. The electrical signal is sent to the vibrator 47 via the electrical cable 66. Although two conducting wires are connected to the vibrator 47 (see Fig. 5), in Fig. 8, the electrical cable 66 is simplified and illustrated as a single line. The frequency of the ultrasonic waves generated in the vibrator 47 is, for example, 28 kHz, and the ultrasonic output is, for example, 10W to 100W. The ON / OFF of the electrical signal is controlled by a timer. Also, the ultrasonic output is monitored by measuring and recording the load current value.

[0043] The air compressor 62 generates compressed air. The regulator 63 regulates the pressure of the compressed air (for example, reduces the pressure to 0.2 MPa). The air dryer 64 removes moisture in the compressed air and dries it, and supplies it to the air supply port 451 of the rod body 40 via the air tube 65. In addition to the above insulation structure on the vibrator 47 side, by removing moisture in the compressed air by the air dryer 64, it is possible to more reliably prevent a short circuit due to moisture adhesion to the connection terminal 475. Also, by adjusting the supply air pressure by the regulator 63, variations in cooling performance can be reduced. In addition, when other devices use air, it can also be diverted as the cooling air for the vibrator 47.

[0044] The electric cable 66 that sends an electric signal from the ultrasonic oscillator 61 to the vibrator 47 is inserted inside the air tube 65 connected to the air supply port 451 of the rod body 40. As a result, there is no need to separately provide an inlet for pulling in the electric cable in the rod body 40, simplifying the wiring. Also, it protects against damage to the coating of the electric cable. Further, the work of the air piping and the electric signal wiring can be performed at once. Moreover, it is possible to prevent air leakage from the junction part that is a concern when the electric cable is joined in the middle of the air path.

[0045] Next, with reference to the flowchart of FIG. 9 and FIGS. 10 and 11, an ultrasonic vibration chemical solution injection method according to an embodiment will be described. The symbol "S" in the flowchart means step. In the installation step of S11, the devices, equipment, etc. that make up the ultrasonic vibration chemical solution injection system 100 are carried in, and a plant is temporarily installed around the access shaft 91 that has been reached. The devices that make up the system 100 include a chemical solution supply device 50, an ultrasonic oscillator 61, and an air supply device 620.

[0046] Prior to S12, the position of the chemical solution injection point GP is determined around the planned penetration part 93. In the attachment step of S12, an operator welds and fixes the flat steel 31 of the shaft attachment fitting 30 at the position corresponding to the injection point GP on the shaft wall 92. FIG. 10 shows two patterns as specific work examples of the attachment step. From the initial state 0 to the completed state 3, in pattern A, the work is carried out in the order of 0 → 1A → 2A → 3, and in pattern B, the work is carried out in the order of 0 → 1B → 2B → 3. In the completed state 3, a wooden plug 96 is fitted into the sounding hole 95 to prevent water from flowing out of the sounding hole 95.

[0047] In pattern A, the operator first drills a sounding hole 95 in the shaft wall 92 (1A), checks the degree of water outflow, and fits a wooden plug 96 into the sounding hole 95 (2A). The wooden plug 96 is made of wood appropriately processed according to the size of the sounding hole 95 and is driven in with a hammer. Then, the operator welds the flat steel 31 of the shaft attachment fitting 30 to the shaft wall 92 around the sounding hole 95.

[0048] In Pattern B, the operator first welds the flat steel 31 of the shaft attachment fitting 30 to the shaft wall 92 (1B). Then, the operator drills a probing hole 95 in the shaft wall 92 inside the opening of the shaft attachment fitting 30 (2B) and fits a wooden plug 96 into the probing hole 95.

[0049] Before S13, as preparation for the connection process, the rod body 40 is suspended into the destination shaft 91 by a crane while maintaining a horizontal position. When the tip of the rod body 40 is held at a position facing the shaft attachment fitting 30, the wooden plug 96 is removed immediately before the connection process. In the connection process of S13, the operator connects the tip of the rod body 40 to the shaft attachment fitting 30. By this connection, the chemical solution injection rod 20 is formed.

[0050] Fig. 11 shows the procedure of the connection process between the shaft attachment jig 30 and the rod body 40. The connection part 42 of the rod body 40 is rotatable about the fulcrum of the lever 42L of the cam lock female. In Step 1-2, with the lever 42L unlocked, the connector 32C fixed to the socket 32 of the shaft attachment fitting 30 is inserted into the connection part 42 of the rod body 40, and the male and female of the cam lock are engaged. In Steps 3-4 after insertion, the lever 42L is locked with the shaft attachment jig 30 and the rod body 40 connected.

[0051] In the injection process of S14, with the chemical solution injection rod 20, the main agent and the hardening agent supplied from the chemical solution supply device 50 are mixed and sent out, and while cooling the vibrator 47 with the air supplied from the air supply device 620, the ultrasonic vibration generated by the vibrator 47 is applied to the chemical solution and the ground, and the chemical solution is injected into the injection point GP. The flow of the chemical solution and air and the generation of ultrasonic vibration in the injection process are as described above with reference to Figs. 4 and 6.

[0052] When the chemical solution injection per injection point GP is completed, the supply of the chemical solution from the chemical solution supply device 50, the supply of air from the air supply device 620, and the output of the electrical signal from the ultrasonic oscillator 61 are stopped. In S15, the connection between the shaft attachment jig 30 and the rod body 40 is released. Then, the chemical solution remaining in the chemical solution passage 44 is removed and the inside of the rod body 40 is cleaned.

[0053] In the construction where the shield hole diameter is large or in the soft ground construction where the groundwater volume is large, it may be necessary to inject the chemical solution at a plurality of locations around the planned penetration portion 93. In S16, it is determined whether chemical solution injection is also required at other locations. Regarding this determination, it may be planned to set a plurality of injection points GP from the beginning, or it may be determined while checking the change in the ground state due to the injection. If it is determined that injection is also required at other locations (S16: YES), S12 to S15 are repeated. The shaft attachment fitting 30 is assumed to be removed from the shaft wall 92 and not reusable, and a plurality of spares are prepared.

[0054] When the ground strengthening is sufficiently achieved and it is determined that injection is not required at other locations (S16: NO), the plant is removed in S17. Thus, the ultrasonic vibration chemical solution injection method of the present embodiment ends.

[0055] The effect of the ultrasonic vibration chemical solution injection method according to the present embodiment will be described in comparison with a general chemical solution injection method. FIG. 12 shows a flowchart of a general chemical solution injection method as a comparative example. In the installation process of S91, devices, equipment, etc. are carried in, and a plant is temporarily installed around the arrival shaft 91. In S92, a boring machine is installed.

[0056] In the drilling process of S93, a hole is formed by a boring machine from the ground above the tunnel. In the injection process of S94, the chemical solution is injected into the ground through the injection pipe penetrated into the drilled hole. When the chemical solution injection per drilled hole is completed, in S95, the injection pipe is pulled out and the drilled hole is filled.

[0057] In S96, it is determined whether chemical solution injection is required at other locations. If YES, S93 to S95 are repeated. In the construction method of the comparative example, as described in paragraphs

[0010] ,

[0015] , etc. of Patent Document 2, for example, a large number of drilled holes are generally formed at a 1 m pitch, and the loop of S93 to S95 is repeated many times. When the chemical solution injection is completed for all the drilled holes, the plant is removed in S97.

[0058] When compared with a general chemical solution injection method, there is no significant difference between S11 and S17 regarding the installation and removal of the plant and S91 and S97. However, in this embodiment, processes such as the installation of the boring machine, drilling, and pulling out of the injection pipe, which are specific to the comparative example, i.e., S92, S93, and S94, become unnecessary. These processes are large-scale processes performed by specialized contractors. On the other hand, the processes of installing the shaft attachment fitting 30, connecting and disconnecting the rod body 40, i.e., S12, S13, and S15, implemented in this embodiment are simple processes that can be performed by the shield construction contractor himself. Therefore, in this embodiment, large-scale processes are unnecessary and are replaced by simple processes.

[0059] For the shield construction contractor, in the construction method of the comparative example, since it takes time to arrange specialized contractors and prepare for construction, there are also management problems such as the construction schedule being extended and the cost increasing. The construction method of this embodiment is a simple method that can be performed by the shield construction contractor himself, so it is also advantageous in terms of schedule management and cost reduction.

[0060] Also, in the injection process S94 of the comparative example, in order to penetrate the chemical solution widely through the injection pipe penetrating the drilled hole, there was a concern that the chemical solution would not penetrate to the target points around the planned penetration area, and it was impossible to surely prevent the gushing of groundwater. On the other hand, in the injection process S14 of this embodiment, the target injection point GP is specified and the chemical solution is injected pinpoint, and moreover, the ultrasonic vibration is used to effectively penetrate the chemical solution, so the effect of ground strengthening by one-time chemical solution injection is improved.

[0061] Therefore, if the shield hole diameter and ground conditions are the same, the number of times determined as "injection required at other locations" in S16 is less than that in S96. In the case of a construction with a relatively small shield hole diameter, in the ultrasonic vibration chemical solution injection method according to the present embodiment, it is highly likely that ground strengthening can be completed with a single chemical solution injection. Therefore, compared with general chemical solution injection methods, the total implementation time can be shortened. Furthermore, groundwater gushing can be more reliably prevented, improving safety.

[0062] <Other Embodiments> (1) The connection structure between the shaft attachment fitting 30 and the rod body 40 constituting the chemical solution injection rod 20 is not limited to using a cam lock, and other connection means may be used.

[0063] (2) The arrangement of the main agent passage 441, the hardener passage 442, and the air passage 46 in the rod body 40 is not limited to the triple tube structure shown in Fig. 3(b), and they may be formed separately from each other as long as they are isolated. For example, the main agent passage 441 and the hardener passage 442 may be separated left and right by the wall inside the tube. Also, the mixing position of the main agent and the hardener is determined by characteristics such as the solidification time after mixing. When using a chemical agent with a long solidification time, the main agent and the hardener may be mixed further behind the rod body 40.

[0064] (3) The ultrasonic oscillator 61 and the air supply device 620 do not have to form the unit 60 and may be separately arranged. When the influence of moisture in the compressed air is not a problem, the air supply device 620 does not have to include an air dryer 64. The air supply device 620 is not limited to generating and supplying compressed air inside the system, and may also regulate the pressure of the air supplied from outside the system (for example, another adjacent construction facility) and re - supply it.

[0065] As described above, the present invention is not limited to the above - described embodiments, and can be implemented in various forms without departing from the gist thereof.

Explanation of Reference Numerals

[0066] 100 ··· Ultrasonic vibration chemical solution injection system, 20 ··· Chemical solution injection rod, 30 ··· Shaft pit attachment fitting, 40 ··· Rod body, 441 ··· Main agent passage, 442 ··· Hardening agent passage, 444 ··· Chemical solution mixing chamber, 451 ··· Air supply port, 46 ··· Air passage, 47 ··· Vibrator, 50 ··· Chemical solution supply device, 61 ··· Ultrasonic oscillator, 620 ··· Air supply device, 62 ··· Air compressor, 63 ··· Regulator, 64 ··· Air dryer, 65 ··· Air tube, 66 ··· Electric cable, 91 ··· Reached shaft pit, 92 ··· Shaft pit wall, 93 ··· Penetration planned area, GP ··· Injection point.

Claims

1. In a tunnel excavation work by the shield method, a chemical solution injection system for injecting a chemical solution for preventing the gushing of groundwater around a planned penetration part (93) by using ultrasonic vibration prior to penetration into the arrival shaft (91), comprising: a shaft mounting fitting (30) fixed to the shaft wall (92), and a rod body (40) having a tip connected to the shaft mounting fitting and capable of delivering a chemical solution in which a main agent and a curing agent are mixed, and having an oscillator (47) provided therein for generating ultrasonic vibration by an electric signal, and a chemical solution injection rod (20) for injecting the chemical solution into the injection point (GP) while applying the ultrasonic vibration generated by the oscillator to the chemical solution and the ground; a chemical solution supply device (50) for supplying the main agent and the curing agent to the chemical solution injection rod respectively; an ultrasonic oscillator (61) for outputting an electric signal for generating ultrasonic vibration to the oscillator; an air supply device (620) for supplying air for cooling the oscillator to the chemical solution injection rod when ultrasonic vibration is generated, and the rod body is an ultrasonic vibration chemical solution injection system in which a main agent passage (441) and a curing agent passage (442) through which the main agent and the curing agent supplied from the chemical solution supply device are respectively sent toward a chemical solution mixing chamber (444) formed on the tip side, and an air passage (46) for introducing the air supplied from the air supply device around the oscillator are formed so as to be isolated from each other.

2. The ultrasonic vibration chemical solution injection system according to claim 1, wherein the rod body is formed in a triple tube structure in which the main agent passage, the curing agent passage, and the air passage are coaxial.

3. The air supply device is an air compressor (62) for generating compressed air, a regulator (63) for regulating the pressure of the compressed air, an air dryer (64) for removing moisture in the compressed air and supplying it to the rod body, and the ultrasonic vibration chemical solution injection system according to claim 1 including the same.

4. The ultrasonic vibration chemical solution injection system according to claim 1, wherein an electric cable (66) for sending an electric signal from the ultrasonic oscillator to the oscillator is inserted inside an air tube (65) connected to an air supply port (451) of the rod body.

5. In a tunnel excavation work by the shield method, a chemical solution injection method for injecting a chemical solution for preventing the gushing of groundwater around a planned penetration part (93) from a chemical solution injection rod (20) by using ultrasonic vibration prior to penetration into the arrival shaft (91), An installation step (S11) of installing a chemical solution supply device (50) that supplies a main agent and a hardening agent to the chemical solution injection rod, an ultrasonic oscillator (61) that outputs an electrical signal, and an air supply device (620) that supplies air to the chemical solution injection rod; An attachment step (S12) of fixing a shaft sinking attachment fitting (30) to a shaft sinking wall (92); A connection step (S13) of connecting the tip of a rod body (40) provided inside with a vibrator (47) that generates ultrasonic vibration by the electrical signal output by the ultrasonic oscillator to the shaft sinking attachment fitting to form the chemical solution injection rod; An injection step (S14) of mixing and delivering the main agent and the hardening agent supplied from the chemical solution supply device with the chemical solution injection rod, and applying the ultrasonic vibration generated by the vibrator while cooling the vibrator with the air supplied from the air supply device to the chemical solution and the ground, and injecting the chemical solution into an injection point (GP); An ultrasonic vibration chemical solution injection method including the above steps.

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