A device for implementing slurry shield function of earth pressure shield and a method for using the same

Abstract

The present application relates to earth pressure shield technical field, especially to a kind of earth pressure shield realizes slurry shield function's device and its use method, comprising: earth pressure shield machine body, cutterhead and screw conveyor;The advancing end of the earth pressure shield machine body is equipped with soil bin wall, and the side of soil bin wall is connected with main drive;Main drive is connected with cutterhead through cutterhead bracket;The cutterhead is enclosed with soil bin wall and the front section of earth pressure shield machine body to form soil bin;The feed inlet of the screw conveyor is communicated with the bottom of soil bin, and the discharge port of screw conveyor is communicated with pressure regulating assembly for changing the pressure in soil bin, and pressure regulating assembly is electrically connected with pressure sensor arranged in soil bin.The device adjusts earth pressure shield working back pressure, solves the problem that surface subsidence is difficult to control in hard rock stratum excavation of earth pressure balance shield in soft upper and hard lower, and simultaneously realizes the function of slurry shield, reduces construction cost.

Description

Technical Field

[0001] This invention relates to the field of earth pressure shield technology, and in particular to an earth pressure shield with the function of realizing slurry shield tunneling and its usage method. Background Technology

[0002] With the large-scale development of subway construction in China, tunnel boring machine (TBM) construction has become widely used in subway and urban railway construction due to its safety, efficiency, and wide adaptability. Currently, TBMs are divided into slurry shields and earth pressure shields, each with its own advantages and disadvantages.

[0003] Earth pressure shield tunneling relies on the soil plug effect of the screw conveyor to establish soil pressure within the chamber, effectively balancing external earth and water pressure, maintaining the stability of the working face, resulting in less settlement, a wide range of applications, suitability for mixed strata, easier disposal of excavated soil, and lower costs. However, it faces significant construction challenges when tunneling through mixed strata with high permeability, high water permeability, and especially water-rich hard rock and sand layers, as it encounters problems such as gushing and difficulty in controlling surface settlement.

[0004] Slurry shield tunneling relies on slurry to control slurry pressure, maintaining working face stability and minimizing settlement. Soil removal is achieved through slurry pipes, preventing gushing even in areas with high water pressure. However, slurry shield tunneling is more expensive, suffers from pipe wear and slow recovery from blockages, and requires significant land area. In cohesive strata and complex formations with good self-stability, slurry shield tunneling is far less economical and efficient than earth pressure shield tunneling. Even in mixed formations of hard rock and sand, the slurry concentration is limited by pipe drainage, which can still lead to surface settlement.

[0005] This shows that earth pressure shield tunneling and slurry shield tunneling each have their limitations in current shield tunneling construction. Their advantages and disadvantages are contradictory, and their application in complex strata construction, such as in Qingdao, will face many challenges in terms of selection, risk, and cost. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a device and a method for using an earth pressure balance shield tunneling machine that can realize the function of a slurry shield tunneling machine. This device not only solves the problems of easy gushing and difficult control of surface settlement when the earth pressure balance shield tunneling machine is tunneling through highly permeable, hard rock strata with soft upper and hard lower layers, but also realizes the functions of earth pressure balance shield tunneling machine and slurry shield tunneling machine on one earth pressure balance shield tunneling machine at the same time. Moreover, the two functions can be quickly switched within a few minutes, which reduces construction costs and improves construction efficiency.

[0007] To achieve the aforementioned objective, the technical solution of the present invention is implemented as follows: a device for realizing the function of a slurry shield tunneling machine using earth pressure shield tunneling, comprising: an earth pressure shield machine body, a cutterhead, and a screw conveyor; the forward end of the earth pressure shield machine body is provided with an earth chamber wall, one side of which is connected to the main drive; the main drive is connected to the cutterhead via a cutterhead bracket; the cutterhead, the earth chamber wall, and the front section of the earth pressure shield machine body together form an earth chamber; the feed inlet of the screw conveyor is connected to the bottom of the earth chamber, and the discharge outlet of the screw conveyor is connected to a pressure regulating component that changes the internal pressure of the earth chamber; the pressure regulating component is connected to a pressure sensor arranged inside the earth chamber.

[0008] Preferably, it also includes a soil conveyor belt; the pressure regulating component includes a transition section; the transition section has an inlet and an outlet on both sides, and a horizontal gate that can be opened and closed is provided at the bottom of the transition section; the inlet of the transition section is connected to the outlet of the screw conveyor, and the horizontal gate of the transition section is connected to the receiving end of the soil conveyor belt.

[0009] Preferably, the pressure regulating assembly further includes a wear-resistant hose and a soil plug; one end of the wear-resistant hose is connected to the outlet of the transition section, and a vertical gate is provided at the connection point; the other end of the wear-resistant hose is connected to one end of the soil plug; the wear-resistant hose can be used as a flexible connection when the shield turns.

[0010] Preferably, the plug tube is formed by splicing at least two short pipes end to end, and a tension cylinder and a ball valve are provided on both sides of the short pipe at the end to facilitate adjustment of the pipe section assembly length and to pull open any pipe section for cleaning when blocked.

[0011] Preferably, the pressure regulating component further includes an air cushion chamber; the top of the air cushion chamber is connected to an air supply device that provides compressed gas to the air cushion chamber, one side of the bottom of the air cushion chamber is connected to a soil mixing device that provides bentonite slurry to the air cushion chamber, and the other side of the bottom of the air cushion chamber is connected to a soil chamber.

[0012] Preferably, the air cushion chamber is equipped with a liquid level sensor; the working chamber of the air cushion chamber is divided vertically into high liquid level lines and low liquid level lines for marking the volume of bentonite slurry in the air cushion chamber; the detection point of the liquid level sensor is located on the high liquid level line and the low liquid level line.

[0013] Preferably, the pressure regulating component further includes an automatic slurry replenishment controller; the automatic slurry replenishment controller is electrically connected to the air supply device, the soil mixing device, the liquid level sensor, and the pressure sensor.

[0014] Preferably, the pressure sensor is installed on the surface of the soil chamber wall opposite to the cutterhead.

[0015] Preferably, it also includes an equipment bridge; the equipment bridge is installed at the rear end of the earth pressure shield machine body; the air cushion chamber, soil conveying belt and soil plug pipe are all fixed on the equipment bridge.

[0016] Preferably, the method is as follows:

[0017] S1, when the earth pressure shield machine starts the earth pressure mode, the soil excavated by the cutterhead enters the soil chamber, and the screw conveyor transports the soil in the soil chamber to the transition section.

[0018] S2, the operator directly opens the horizontal gate at the bottom of the transition section and closes the vertical gate on the transition section; the soil in the transition section falls directly onto the receiving end of the soil conveyor belt, and the soil falling onto the soil conveyor belt is transported by the soil conveyor belt and then falls into the soil transfer vehicle, and the soil is transported out of the working area of ​​the earth pressure shield machine body by the transfer vehicle.

[0019] S3. When the earth pressure shield machine body is in slurry mode, the operator closes the horizontal gate at the bottom of the transition section and opens the vertical gate. At the same time, the operator adjusts the number of sections of the splicing short pipe of the soil plug tube according to the pressure value of the pressure sensor in the soil chamber to create a soil plug effect and provide back pressure to the soil chamber.

[0020] S4, the soil mixing device injects bentonite slurry into the air cushion chamber through the pipeline until the liquid level sensor detects that the bentonite slurry in the air cushion chamber has reached the high liquid level line of the working chamber of the air cushion chamber and then stops the injection.

[0021] S5, the automatic slurry filling controller starts the air supply device to inject compressed air into the top of the pressure chamber based on the real-time change of the pressure value of the pressure sensor, and presses the bentonite slurry in the air cushion chamber into the soil chamber through the pipeline equipped with a one-way valve to maintain the back pressure of the soil chamber in a stable state.

[0022] S6, the mud in the soil chamber is transported into the soil plug pipe by a screw conveyor, and finally falls into the soil transfer vehicle parked at the rear end of the soil plug pipe.

[0023] The beneficial effects of this invention are reflected in:

[0024] (1) This invention adds a transition section to the screw conveyor of the earth pressure shield machine. The horizontal and vertical gates of the transition section can control the flow direction of the excavated soil, thereby controlling the conversion between earth pressure and slurry shield modes. At the same time, slurry is actively added to the soil chamber of the earth pressure shield machine to actively adjust the back pressure of the soil chamber and keep it in a stable state. This ensures that the earth pressure shield machine can actively deal with the problem of gushing in water-rich strata or the settlement problem that occurs when excavating soil in hard rock strata with soft upper and hard lower layers. This enables the earth pressure shield machine to achieve the function of slurry shield tunneling with mud film pressure. The control equipment such as soil plug pipe and air cushion chamber has low cost and is easy to promote.

[0025] (2) This invention establishes a soil plug effect by adding a transition section and a soil plug pipe to the discharge port of the screw conveyor, thereby adjusting the back pressure of the soil chamber of the earth pressure shield machine. Simultaneously, a transition section is established, with a horizontal gate at its bottom, which connects to the receiving end of the soil conveyor belt. This configuration allows the earth pressure shield machine to complete the soil transfer function in earth pressure mode simply by opening the horizontal gate at the bottom of the transition section, making it simple and efficient.

[0026] (3) The present invention sets the soil plug pipe to be composed of at least two spliced ​​short pipes connected end to end, and sets a tensioning cylinder at the tail of the soil plug pipe on multiple pipe sections. With this setting, it is easy to make simple adjustments at any pipe section using the cylinder, so that the length of the soil plug pipe can be adjusted according to the back pressure required by the soil chamber of the earth pressure shield machine, which improves the flexibility and convenience of the device and reduces the operating intensity.

[0027] (4) This invention includes an air cushion chamber. The top of the air cushion chamber is connected to an air supply device, and the two sides of the bottom of the air cushion chamber are connected to a soil mixing device and a soil chamber, respectively. By injecting mud into the air cushion chamber and then injecting compressed air to force the mud into the soil chamber, the back pressure of the soil chamber can be adjusted to ensure that the back pressure of the soil chamber of the earth pressure shield machine is stable in the slurry mode. This automatic adjustment method not only maintains the stability of the working face of the earth pressure shield machine and minimizes settlement, but also makes the entire adjustment method simple, efficient, and easy to implement.

[0028] (5) The present invention sets a ball valve on the spliced ​​short pipe of the soil plug tube. The soil plug tube can be flushed by connecting a high-pressure water pipe through the ball valve, or a polymer can be injected through the ball valve to improve the viscosity of the soil in the soil plug tube, so as to facilitate the generation of soil plug effect and establish back pressure.

[0029] (6) This invention includes a liquid level sensor and high and low liquid level lines for marking the volume of bentonite slurry within the air cushion chamber. The detection points of the liquid level sensor are located on these high and low liquid level lines. This configuration allows for real-time monitoring of the bentonite slurry level within the air cushion chamber, facilitating timely replenishment, ensuring stable operation of the air cushion chamber, and improving the overall stability of the device.

[0030] (7) The present invention includes an automatic slurry replenishment controller; the automatic slurry replenishment controller is electrically connected to the air supply device, the soil mixing and pumping device, the liquid level sensor, and the pressure sensor. In actual use, this method achieves automated control and improves the accuracy of the device.

[0031] (8) The present invention provides a wear-resistant flexible hose between the transition section and the soil plug pipe, thereby facilitating turning and flexible connection. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Cutterhead; 2. Soil chamber; 3. Cutterhead support; 4. Pressure sensor; 5. Soil chamber wall; 6. Main drive; 7. Screw conveyor; 8. Tunnel boring machine body; 9. Transition section feed inlet; 10. Transition section; 11. Horizontal gate; 12. Vertical gate; 13. Soil conveyor belt; 14. Wear-resistant hose; 15. Soil plug pipe; 16. Equipment bridge; 17. Air cushion chamber; 18. Tension cylinder. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] See Figure 1 As shown:

[0038] The present invention provides a device for realizing the function of earth pressure shield tunneling machine in slurry shield tunneling, comprising: earth pressure shield machine body 8, cutterhead 1, pressure sensor 4, screw conveyor 7, soil conveying belt 13 and equipment bridge 16.

[0039] A cutterhead 1 is installed at the forward end of the earth pressure shield tunneling machine body 8, and one side of the soil chamber wall 5 is connected to the main drive 6. The main drive 6 is connected to the cutterhead 1 through the cutterhead bracket 3, and the pressure sensor 4 is installed on the surface of the soil chamber wall 5 opposite to the cutterhead 1. The cutterhead 1 and the front shell of the earth pressure shield tunneling machine body 8 together form the soil chamber 2. The equipment bridge 16 is installed at the rear end of the earth pressure shield tunneling machine body 8.

[0040] The feed inlet of the screw conveyor 7 is connected to the bottom of the soil chamber 2, and the discharge outlet of the screw conveyor 7 is connected to the pressure regulating component that changes the internal pressure of the soil chamber 2. The pressure regulating component is connected to the pressure sensor 4 arranged inside the soil chamber 2.

[0041] When the earth pressure shield machine is in slurry working mode, the pressure regulating component actively adjusts the pressure in the soil chamber 2 according to the changes in the value of the pressure sensor 4 in the soil chamber 2, so as to stabilize the back pressure in the soil chamber 2, thereby ensuring that the earth pressure shield machine enters a safe and reliable construction mode.

[0042] The pressure regulating assembly consists of a transition section 10, a wear-resistant hose 14, a soil plug tube 15, an air cushion chamber 17, and an automatic grouting controller. One end of the wear-resistant hose 14 is connected to the outlet of the transition section 10, and the other end of the wear-resistant hose 14 is connected to one end of the soil plug tube 15. The wear-resistant hose 14 is easy to bend, providing a flexible connection.

[0043] The screw conveyor 7 uses a peripheral drive to transport the soil in the soil bin 2, so that the soil can enter from the bottom of the soil bin 2 along the feed port of the screw conveyor 7 and exit along the discharge port of the screw conveyor 7, and the discharge port of the screw conveyor 7 is connected to the feed port 9 of the transition section.

[0044] An extended conveying pipe is installed between the screw conveyor 7 and the transition section 10. In actual use, both ends of the extended conveying pipe are connected to the screw conveyor 7 and the transition section 10 respectively via flanges. This is mainly to create a soil plug effect in the soil chamber 2, thereby increasing the back pressure of the soil chamber 2 and ensuring the stable operation of the cutterhead 1. In actual operation, the pipe is disassembled and assembled according to the working environment of the earth pressure shield machine, making it quite flexible in use.

[0045] The bottom of the transition section 10 is equipped with an openable horizontal gate 11, which is connected to the receiving end of the soil conveying belt 13 fixed on the equipment bridge 16. In the earth pressure shield machine's working mode, after the horizontal gate 11 is opened, the soil is transported to the transition section 10 and falls directly onto the soil conveying belt 13, which then transports the soil to the next soil processing stage.

[0046] A vertical gate 12 is provided on the other side of the transition section 10. The vertical gate 12 of the transition section 10 is connected to one end of the wear-resistant hose 14. The soil plug pipe 15 is formed by splicing at least two short pipes end to end. The soil plug pipe 15 is fixed on the equipment bridge 16.

[0047] In slurry working mode, the earth pressure shield machine adjusts the number of sections of the spliced ​​short pipes, thereby adjusting the length of the soil plug pipe 15, thus forming a soil plug effect and adjusting the back pressure of the soil chamber 2.

[0048] A ball valve is installed on the spliced ​​short pipe. Connecting the ball valve to the pipeline supplying the polymer can improve the viscosity of the soil in the soil plug tube 15, facilitating subsequent transportation and transfer of the soil. Similarly, during use, connecting the ball valve to a high-pressure water pipe allows for flushing of the interior of the soil plug tube 15.

[0049] The vertical gate 12 is designed to allow the earth pressure shield machine to close the soil plug 15 in earth pressure working mode, ensuring that the soil can only exit through the horizontal gate 11 at the bottom of the transition section 10.

[0050] The air cushion chamber 17 is fixed to the equipment bridge 16. One side of the bottom of the air cushion chamber 17 is connected to a soil mixing device via a pipe, which supplies bentonite slurry to the air cushion chamber 17. The other side of the bottom of the air cushion chamber 17 is connected to the soil chamber 2. A liquid level sensor is installed inside the air cushion chamber 17. The working chamber of the air cushion chamber 17 is vertically divided into high liquid level lines and low liquid level lines to mark the volume of bentonite slurry inside the air cushion chamber 17. The detection points of the liquid level sensor are located on the high liquid level lines and low liquid level lines.

[0051] The top of the air cushion chamber 17 is connected to the air supply device via a connecting air pipe. The air supply device provides compressed gas to the air cushion chamber 17. The automatic slurry filling controller is electrically connected to the air supply device, the soil mixing device, the liquid level sensor, and the pressure sensor 4.

[0052] When the back pressure in soil chamber 2 is unstable, the automatic slurry injection controller, based on the pressure sensor 4 readings within soil chamber 2, activates the soil mixing device to inject bentonite slurry into air cushion chamber 17. Injection stops when the level sensor detects that the volume of bentonite slurry in the working chamber of air cushion chamber 17 has reached the high level line. Simultaneously, the air supply device is activated to inject compressed gas into the top of air cushion chamber 17, causing the bentonite slurry within air cushion chamber 17 to be forced into soil chamber 2 along a pipeline equipped with a one-way valve. When the level sensor in air cushion chamber 17 detects that the volume of bentonite slurry in the working chamber of air cushion chamber 17 has reached the low level line, the soil mixing device is restarted to inject bentonite slurry into air cushion chamber 17. In this way, the pressure within soil chamber 2 is actively adjusted to stabilize its back pressure.

[0053] In practical use, the most commonly available computer-based automatic grouting controller is preferred.

[0054] Example 2

[0055] The specific operating steps for using this device are as follows:

[0056] S1, when the earth pressure shield machine starts the earth pressure mode, the soil excavated by the cutterhead 1 enters the soil chamber 2, and the screw conveyor 7 transports the soil in the soil chamber 2 to the transition section 10.

[0057] S2, the operator directly opens the horizontal gate 11 at the bottom of the transition section 10 and closes the vertical gate 12. The soil in the transition section 10 falls directly onto the receiving end of the soil conveyor belt 13. The soil falling onto the soil conveyor belt 13 is then transported by the soil conveyor belt 13 and falls into the soil transfer vehicle. The soil is then transported out of the working area of ​​the earth pressure shield machine body 8 by the transfer vehicle.

[0058] S3. When the earth pressure shield machine is in slurry mode, the operator closes the horizontal gate 11 at the bottom of the transition section 10 and opens the vertical gate 12. At the same time, the operator adjusts the number of spliced ​​short pipe sections of the soil plug pipe 15 according to the pressure value of the pressure sensor 4 in the soil chamber 2 to create a soil plug effect and provide back pressure for the soil chamber 2.

[0059] S4, the soil mixing device injects bentonite slurry into the air cushion chamber 17 through the pipeline until the liquid level sensor detects that the bentonite slurry in the air cushion chamber 17 has reached the high liquid level line of the working chamber of the air cushion chamber 17 and then stops the injection.

[0060] S5, the automatic slurry filling controller starts the air supply device to inject compressed air into the top of the pressure chamber based on the real-time change of the pressure value of the pressure sensor 4, and presses the bentonite slurry in the air cushion chamber 17 into the soil chamber 2 through the pipeline equipped with a one-way valve, so as to maintain the back pressure of the soil chamber 2 in a stable state.

[0061] S6, the mud in the soil chamber 2 is transported into the soil plug pipe 15 by the screw conveyor 7, and finally falls into the soil transfer vehicle parked at the rear end of the soil plug pipe 15.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for realizing the function of a slurry shield tunneling machine using earth pressure balance tunneling, characterized in that, include: Earth pressure shield machine body (8), cutterhead (1) and screw conveyor (7); the forward end of the earth pressure shield machine body (8) is provided with a soil chamber wall (5), one side of the soil chamber wall (5) is connected to the main drive (6); the main drive (6) is connected to the cutterhead (1) through the cutterhead bracket (3); the cutterhead (1), the soil chamber wall (5) and the front section of the earth pressure shield machine body (8) together form a soil chamber (2); the feed inlet of the screw conveyor (7) is connected to the bottom of the soil chamber (2), the discharge outlet of the screw conveyor (7) is connected to the pressure regulating component that changes the internal pressure of the soil chamber (2), and the pressure regulating component is electrically connected to the pressure sensor (4) arranged in the soil chamber (2); It also includes a soil conveyor belt (13); the pressure regulating component includes a transition section (10); the two sides of the transition section (10) are respectively provided with an inlet and an outlet, and the bottom of the transition section (10) is provided with a horizontal gate (11) that can be opened and closed; the inlet of the transition section (10) is connected to the outlet of the screw conveyor (7), and the horizontal gate (11) of the transition section (10) is connected to the receiving end of the soil conveyor belt (13); The pressure regulating assembly also includes a wear-resistant hose (14) and a soil plug (15); one end of the wear-resistant hose (14) is connected to the outlet of the transition section (10), and a vertical gate (12) is provided at the connection point; the other end of the wear-resistant hose (14) is connected to one end of the soil plug (15). The soil plug tube (15) is formed by splicing together at least two spliced ​​short tubes end to end, and a tension cylinder (18) and a ball valve are provided on both sides of the spliced ​​short tube at the end; the tension cylinder (18) is used to adjust the length of any two spliced ​​short tubes at the splice, so that the length of the soil plug tube can be adjusted according to the back pressure required by the soil chamber of the earth pressure shield machine. The pressure regulating assembly also includes an air cushion chamber (17); the top of the air cushion chamber (17) is connected to an air supply device that provides compressed gas to the air cushion chamber (17), one side of the bottom of the air cushion chamber (17) is connected to a soil mixing device that provides bentonite slurry to the air cushion chamber (17), and the other side of the bottom of the air cushion chamber (17) is connected to a soil chamber (2).

2. The device for realizing the function of a slurry shield tunneling machine using earth pressure balance tunneling according to claim 1, characterized in that, The air cushion chamber (17) is equipped with a liquid level sensor; the working chamber of the air cushion chamber (17) is divided vertically into high liquid level lines and low liquid level lines for marking the capacity of bentonite slurry in the air cushion chamber (17); the detection point of the liquid level sensor is set on the high liquid level line and the low liquid level line.

3. The device for realizing the function of a slurry shield tunneling machine using earth pressure balance tunneling according to claim 2, characterized in that, The pressure regulating component also includes an automatic slurry filling controller; the automatic slurry filling controller is electrically connected to the air supply device, the soil mixing device, the liquid level sensor and the pressure sensor (4).

4. The device for realizing the function of a slurry shield tunneling machine using earth pressure balance tunneling according to claim 3, characterized in that, The pressure sensor (4) is installed on the surface of the earth chamber wall (5) opposite to the cutterhead (1).

5. The device for realizing the function of a slurry shield tunneling machine using earth pressure shield tunneling according to claim 4, characterized in that, It also includes an equipment bridge (16); the equipment bridge (16) is installed at the rear end of the earth pressure shield machine body (8); the air cushion chamber (17), the soil conveying belt (13) and the soil plug pipe (15) are all fixed on the equipment bridge (16).

6. A method for using a device for achieving the function of a slurry shield tunneling machine using earth pressure balance tunneling, characterized in that, The device for achieving the function of a slurry shield tunneling machine using any one of claims 1-5 is described in the following method: S1, when the earth pressure shield machine starts the earth pressure mode, the soil excavated by the cutterhead (1) enters the soil chamber (2), and the screw conveyor (7) transports the soil in the soil chamber (2) to the transition section (10). S2, the operator directly opens the horizontal gate (11) at the bottom of the transition section (10) and closes the vertical gate (12) on the transition section (10); the soil in the transition section (10) falls directly onto the receiving end of the soil conveyor belt (13), and the soil falling onto the soil conveyor belt (13) is transported by the soil conveyor belt (13) and then falls into the soil transfer vehicle. The soil is then transported out of the working area of ​​the earth pressure shield machine body (8) by the transfer vehicle. S3, when the earth pressure shield machine body (8) is in slurry mode, the operator closes the horizontal gate (11) at the bottom of the transition section (10) and opens the vertical gate (12); at the same time, the operator adjusts the number of sections of the splicing short pipe of the soil plug pipe (15) according to the pressure value of the pressure sensor (4) in the soil chamber (2) to create a soil plug effect and provide back pressure for the soil chamber (2); S4, the soil mixing device injects bentonite slurry into the air cushion chamber (17) through the pipeline until the liquid level sensor detects that the bentonite slurry in the air cushion chamber (17) has reached the high liquid level line of the working chamber of the air cushion chamber (17) and stops the injection. S5, the automatic grouting controller starts the air supply device to inject compressed air into the top of the pressure chamber according to the real-time change of the pressure value of the pressure sensor (4), and presses the bentonite slurry in the air cushion chamber (17) into the soil chamber (2) through the pipeline equipped with a one-way valve, so as to maintain the back pressure of the soil chamber (2) in a stable state. S6, the mud in the soil chamber (2) is transported into the soil plug pipe (15) by the screw conveyor (7) and finally falls into the soil transfer vehicle parked at the rear end of the soil plug pipe (15).

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