Simulation test device and test method for soil pressure balance shield construction of water-rich sand layer

Abstract

The invention provides a simulation test device and test method for soil pressure balance shield construction of a water-rich sand layer, and relates to the technical field of tunnel construction test. According to the invention, the complex working condition during shield tunneling under the water-rich sand layer condition is highly simulated through the deslagging and slag adding processes of the deslagging system and the slag adding system; meanwhile, the internal air pressure and seepage pressure are adjusted by adjusting the pressure adjusting system according to the required working condition so as to simulate and adjust the air pressure under different burial depths and the tunnel face water head pressure value of the shield tunneling machine under different burial depths or different hydrological conditions, so that whether the improved muck gushes or not can be judged more intuitively; according to the method, the gushing risk can be predicted more accurately, an efficient and accurate model test can be carried out in the shield construction preparation stage, the test efficiency before construction is improved, safe tunneling of a shield is guaranteed, raw materials are saved to the maximum extent, and the economic benefits and environmental friendliness of engineering are improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction testing, and in particular to a simulation testing device and a testing method for earth pressure balance shield construction in a water-rich sand layer. Background Art

[0002] When using earth pressure balance shield to excavate in deep and water-rich sand layers, due to the large permeability coefficient of the sand layer, the water head pressure at the face is large at great depths. It is necessary to inject additives into the face and soil bin to improve the soil so as to improve the soil impermeability, ensure that the spiral earth ejector of the shield machine does not burst, ensure the soil bin pressure, and maintain the balance of the face. However, there is currently a lack of effective methods and devices for testing the effect of improved soil and determining the critical permeability coefficient of bursting under different water head pressures, making it difficult to guide the requirements for soil permeability in actual construction and optimize the improvement ratio scheme. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a simulation test device and test method for earth pressure balance shield construction in water-rich sand layer, so as to solve the problems in the background technology.

[0004] In order to achieve the above-mentioned and other related purposes, the present invention provides a simulation test device for earth pressure balance shield construction in water-rich sand layer, comprising: A soil storage bin, the interior of which is used to load improved slag; A slag discharge system, the slag discharge system comprising a slag discharge pipe and a slag discharge device, the slag discharge pipe is provided with a slag discharge port, and the slag discharge device transfers the slag in the soil storage bin to the slag discharge port for discharge; A slag adding system, the slag adding system comprises a slag adding pipeline and a slag adding regulating module, the slag adding pipeline is connected with the soil storage bin, a slag adding port is provided on the slag adding pipeline, and the slag adding regulating module drives the slag in the slag adding pipeline to enter the soil storage bin; The simulated pressure regulating system includes a pressure control module, an air pressure regulating module and an osmosis regulating module. The pressure control module is connected to the air pressure regulating module and the osmosis regulating module. The air pressure regulating module is connected to the soil storage bin. The osmosis regulating module is connected to the slag adding pipeline.

[0005] Optionally, the walls of the soil storage bin are formed by welding steel plates.

[0006] Optionally, the slag and soil discharge device includes a spiral drive motor and a spiral rod, the spiral rod is arranged inside the slag and soil discharge pipe, and the spiral drive motor drives the spiral rod to rotate and discharge soil.

[0007] Optionally, the air pressure regulating module includes an air pressure regulating pipeline and an air pressure pipeline pressure regulating valve, one end of the air pressure regulating pipeline is connected to the soil storage bin, the other end of the air pressure regulating pipeline is connected to the pressure control module, and the air pressure pipeline pressure regulating valve is installed on the air pressure regulating pipeline.

[0008] Optionally, the osmotic regulation module includes a water storage tank, an osmotic diversion pipeline, an osmotic pressure regulating pipeline and an osmotic pipeline pressure regulating valve; The water storage tank and the slag adding pipeline are connected via the permeation diversion pipeline, the water storage tank and the pressure control module are connected via the permeation pressure regulating pipeline, and the permeation pipeline pressure regulating valve is installed on the permeation pressure regulating pipeline.

[0009] Optionally, the pressure control module includes an air compressor.

[0010] Optionally, a barometer is provided on the top of the soil storing bin, and the barometer is used to display the air pressure value inside the soil storing bin.

[0011] Optionally, the slag adding control module includes a sealed bulldozer piston, a slag adding driving member and a reaction wall; The sealed bulldozer piston is movably arranged inside the slag adding pipeline, the reaction wall is fixedly arranged outside the slag adding pipeline, the slag adding driving member is installed on the reaction wall, and the slag adding driving member pushes the sealed bulldozer piston to move in the slag adding pipeline.

[0012] A test method for a simulation test device based on earth pressure balance shield construction in a water-rich sand layer, comprising: Pre-load the improved slag into the soil storage bin and the slag feeding pipeline; According to the actual air pressure environment of the shield machine at different buried depths, the air pressure value in the soil storage bin is simulated and adjusted through the pressure control module and the air pressure regulating module in the pressure regulating system; Start the slag discharge system and slag feeding system. In the slag discharge system, the slag is discharged through the slag discharge and soil discharge device. In the slag feeding system, the slag is added through the slag feeding control module to achieve a dynamic balance between slag discharge and slag feeding, and simulate the shield tunneling face excavation process and the spiral slag discharge process; While simulating the excavation process, the internal seepage pressure is regulated by the pressure control module and the seepage regulation module in the simulated pressure regulation system, and the head pressure value of the tunnel boring machine at different burial depths or different hydrological conditions is simulated. At the same time, the slag discharge at the slag outlet is observed to determine whether gushing occurs. If gushing or mud and sand bursts occur, the seepage pressure value is recorded.

[0013] Optionally, during the regulation process, the osmotic pressure simulated by the osmotic regulation module is increased step by step, and the osmotic pressure is increased step by step from 0 kPa with an increase gradient of 10 kPa.

[0014] As described above, the simulation test device and test method for water-rich sand layer earth pressure balance shield construction of the present invention have at least the following beneficial effects: The present invention provides a simulation test device for earth pressure balance shield construction in a water-rich sand layer. The complex working conditions of shield tunneling under water-rich sand layer conditions can be highly simulated through the slag discharge and slag addition processes of a slag discharge system and a slag addition system, and the physical and mechanical property changes of the soil body during the earth pressure balance process can be accurately captured. At the same time, according to the required working conditions, the internal air pressure and permeability pressure can be adjusted by adjusting the pressure regulating system to simulate and adjust the air pressure under different burial depths and the water head pressure value of the tunnel face of the shield machine under different burial depths or different hydrological conditions. It can more intuitively judge whether the improved slag will burst, and can more accurately predict the risk of bursting, providing scientific and forward-looking guidance for construction personnel, helping to take measures in advance, and effectively preventing the occurrence of bursting disasters. At the same time, combined with the permeability test, the bursting critical permeability coefficient of the slag under different burial depth conditions can be obtained. The structural composition design of the present invention is compact and easy to operate, so that efficient and accurate model tests can be carried out in the shield construction preparation stage, which not only improves the test efficiency before construction, but also provides strong support for the optimization and adjustment of the construction plan, and helps to save raw materials to the maximum extent while ensuring the safe excavation of the shield, and improve the economic benefits and environmental friendliness of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown is a schematic diagram of the overall layout of a simulation test device for earth pressure balance shield construction in water-rich sand layers according to the present invention. DETAILED DESCRIPTION

[0016] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0017] See also Figure 1 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0018] The following embodiments are only for illustration purposes and can be combined with each other, and are not limited to the contents presented in the following single embodiments.

[0019] See also Figure 1 The present invention provides a simulation test device for earth pressure balance shield construction in a water-rich sand layer, comprising a soil storage bin 1, wherein the interior of the soil storage bin 1 is used to load improved slag; a slag discharge system, wherein the slag discharge system comprises a slag discharge pipe 2 and a slag discharge device, wherein the slag discharge pipe 2 is provided with a slag discharge port 17, and the slag discharge device transfers the slag in the soil storage bin 1 to the slag discharge port 17 for discharge; a slag adding system, wherein the slag adding system comprises a slag adding pipeline 3 and a slag adding regulation module, wherein the slag adding pipeline 3 is connected to the soil storage bin 1, and a slag adding port 18 is provided on the slag adding pipeline 3, and the slag adding regulation module drives the slag in the slag adding pipeline 3 to enter the soil storage bin 1; a simulation pressure regulating system, wherein the simulation pressure regulating system comprises a pressure control module, an air pressure regulating module and a permeability regulating module, wherein the pressure control module is connected to the air pressure regulating module and the permeability regulating module, wherein the air pressure regulating module is connected to the soil storage bin 1, and wherein the permeability regulating module is connected to the slag adding pipeline 3. The present invention provides a simulation test device for earth pressure balance shield construction in a water-rich sand layer. The complex working conditions of shield tunneling under water-rich sand layer conditions can be highly simulated through the slag discharge and slag addition processes of a slag discharge system and a slag addition system, and the physical and mechanical property changes of the soil body during the earth pressure balance process can be accurately captured. At the same time, according to the required working conditions, the internal air pressure and permeability pressure can be adjusted by adjusting the pressure regulating system to simulate and adjust the air pressure under different burial depths and the water head pressure value of the face of the shield machine under different burial depths or different hydrological conditions. It can more intuitively judge whether the improved slag will burst, and can more accurately predict the risk of bursting, providing scientific and forward-looking guidance for construction personnel, which is helpful to take measures in advance and effectively prevent the occurrence of bursting disasters. At the same time, combined with the subsequent permeability test, the bursting critical permeability coefficient of the slag under different burial depth conditions can be obtained. The structural composition design of the present invention is compact and easy to operate, so that efficient and accurate model tests can be carried out in the preparation stage of shield construction, which not only improves the test efficiency before construction, but also provides strong support for the optimization and adjustment of the construction plan, which helps to save raw materials to the maximum extent while ensuring the safe excavation of the shield, and improve the economic benefits and environmental friendliness of the project.

[0020] In this embodiment, the wall of the soil storage bin 1 is welded by steel plates. The steel plate welding structure can ensure the sealing of the soil storage bin 1, prevent the leakage of the improved slag and infiltrated water in the soil storage bin 1, and thus ensure the accuracy and reliability of the test results. In addition, the steel plate material has high strength and rigidity, and can withstand the pressure of the improved slag and infiltrated water in the soil storage bin 1, and ensure the stability and safety of the soil storage bin 1 structure. The steel plate material is easy to process and weld, and can be customized according to the test requirements, which is convenient for assembly and disassembly. Compared with other materials, the cost of steel plates is relatively low, which can reduce the manufacturing cost of the test device.

[0021] In this embodiment, please refer to Figure 1 The slag discharge device includes a spiral drive motor 4 and a spiral rod 5. The spiral rod 5 is arranged inside the slag discharge pipe 2. The spiral drive motor 4 drives the spiral rod 5 to rotate and discharge soil. The spiral rod 5 in the slag discharge device is driven to rotate by the spiral drive motor 4. When the spiral rod 5 rotates, the spiral blades on the spiral rod 5 will gradually push the slag in the soil storage bin 1 to the slag discharge port 17, and discharge the slag through the slag discharge port 17. By controlling the rotation speed of the slag discharge device and the propulsion speed of the slag discharge system, a dynamic balance between slag discharge and slag addition can be achieved, thereby controlling the pressure in the soil storage bin 1.

[0022] In this embodiment, please refer to Figure 1 The air pressure regulating module includes an air pressure regulating pipeline 6 and an air pressure pipeline pressure regulating valve 7. One end of the air pressure regulating pipeline 6 is connected to the soil storage bin 1, and the other end of the air pressure regulating pipeline 6 is connected to the pressure control module. The air pressure pipeline pressure regulating valve 7 is installed on the air pressure regulating pipeline 6. The air pressure pipeline pressure regulating valve 7 can be used to adjust the pressure of the compressed air transmitted to the pressure control module, so as to control the air pressure value in the soil bin. By adjusting the air pressure value through the air pressure pipeline pressure regulating valve 7, the air pressure environment in the actual shield excavation process can be simulated to improve the test accuracy. At the same time, it can prevent the medium pressure from being too high or too low to ensure the safety of equipment and personnel.

[0023] In this embodiment, please refer to Figure 1The permeation regulating module includes a water storage tank 8, a permeation diversion pipeline 9, a permeation pressure regulating pipeline 10 and a permeation pipeline pressure regulating valve 11; the water storage tank 8 and the slag adding pipeline 3 are connected through the permeation diversion pipeline 9, the water storage tank 8 and the pressure control module are connected through the permeation pressure regulating pipeline 10, and the permeation pipeline pressure regulating valve 11 is installed on the permeation pressure regulating pipeline 10. The permeation pipeline pressure regulating valve 11 is used to adjust the pressure of the compressed air transmitted by the pressure control module, so as to control the water pressure in the water storage tank 8. The water storage tank 8 is filled with water, which is connected to the continuous slag adding pipeline 3 through the permeation diversion pipeline 9 and then connected to the soil storage bin 1 to form a closed seepage channel. Optionally, the permeation diversion pipeline 9 can be a rubber tube. The water pressure in the water storage tank 8 can be changed by adjusting the permeation pipeline pressure regulating valve 11, so as to simulate the water head pressure value of the tunnel face of the shield machine under different burial depths or different hydrological conditions. Under pressure, water will seep through the modified soil to form a seepage flow field. By observing the seepage situation, the mechanism of the eruption phenomenon can be studied, providing a theoretical basis for preventing and controlling eruptions.

[0024] In this embodiment, the pressure control module includes an air compressor 12, and the air pressure regulation module and the osmotic regulation module share one air compressor 12. In this configuration, only one air compressor 12 is needed in the device to realize the function, which has lower costs, simpler systems, lower maintenance requirements, and smaller space occupation.

[0025] In this embodiment, the pressure control module includes two air compressors 12, and the air pressure regulating module and the osmotic regulating module are independently configured with an air compressor 12. The two systems operate independently without interfering with each other. Different tests can be carried out at the same time to improve the test efficiency, and the pressure values ​​of the two systems can be controlled separately to improve the test accuracy.

[0026] In this embodiment, please refer to Figure 1 , a barometer 13 is provided on the top of the soil storage bin 1, and the barometer 13 is used to display the air pressure value inside the soil storage bin 1. Setting the barometer 13 can monitor the air pressure value inside the soil storage bin 1 in real time, ensure that the pressure of the soil storage bin 1 meets the test requirements, and simulate the pressure environment of the soil storage bin 1 during the actual shield tunneling process. At the same time, it can be judged whether the pressure of the soil storage bin 1 is stable, and whether it needs to be adjusted to ensure the accuracy of the test results. By controlling the pressure of the soil storage bin 1, the change of the pressure of the soil storage bin 1 during the actual shield tunneling process and the difference in the pressure of the soil storage bin 1 under different burial depths can be simulated. And the barometer 13 can more conveniently record the pressure data of the soil storage bin 1, which is used for subsequent analysis of the test results and judgment of the critical permeability coefficient of the gushing of the improved slag under different pressure conditions.

[0027] In this embodiment, please refer to Figure 1The slag adding control module includes a sealed bulldozer piston 14, a slag adding driving member 15 and a reaction wall 16; the sealed bulldozer piston 14 is movably arranged inside the slag adding pipeline 3, the reaction wall 16 is fixedly arranged outside the slag adding pipeline 3, the slag adding driving member 15 is installed on the reaction wall 16, and the slag adding driving member 15 pushes the sealed bulldozer piston 14 to move in the slag adding pipeline 3. The sealed bulldozer piston 14 can compact the improved slag in the slag adding pipeline 3 to prevent the slag from leaking; optionally, the slag adding driving member 15 can be a hydraulic cylinder, which pushes the sealed bulldozer piston 14 through the extension and contraction of the hydraulic cylinder to send the improved slag into the soil bin. The reaction wall 16 can fix the hydraulic cylinder to provide a reaction force, so that the hydraulic cylinder can push the sealed bulldozer piston 14. The propulsion speed of the hydraulic cylinder can be adjusted to control the speed and amount of slag adding. By adjusting the propulsion speed of the hydraulic cylinder and the discharge speed of the slag discharging system, the dynamic balance of slag discharge and slag adding can be achieved to simulate the real shield tunneling process. The slag adding system can simulate the slag adding process during shield tunneling, as well as the dynamic balance of slag discharge and slag adding, making the test results closer to actual working conditions.

[0028] A test method for a simulation test device based on earth pressure balance shield construction in a water-rich sand layer, comprising: Pre-load the improved slag into the soil storage bin 1 and the slag feeding pipe 3; According to the actual air pressure environment of the shield machine at different buried depths, the air pressure value in the soil storage bin 1 is simulated and adjusted through the pressure control module and the air pressure adjustment module in the pressure adjustment system; Start the slag discharge system and slag feeding system. In the slag discharge system, the slag is discharged through the slag discharge and soil discharge device. In the slag feeding system, the slag is added through the slag feeding control module to achieve a dynamic balance between slag discharge and slag feeding, and simulate the shield tunneling face excavation process and the spiral slag discharge process; While simulating the excavation process, the internal seepage pressure is regulated by the pressure control module and the seepage regulation module in the simulated pressure regulation system, and the head pressure value of the tunnel face of the shield machine under different burial depths or different hydrological conditions is simulated. At the same time, the slag discharge situation of the slag outlet 17 is observed to determine whether gushing occurs. If gushing or mud and sand burst occurs, the seepage pressure value is recorded.

[0029] In this embodiment, in the initial process, a cover plate can be set on the slag adding port 18 to reserve a hole, and the infiltration adjustment module is connected with the slag adding pipeline 3 and the improved slag in the soil storage bin 1 to ensure that a seepage channel can be formed. At this time, the water storage tank 8 in the infiltration adjustment module is filled with water, and the infiltration pipeline pressure regulating valve 11 adjusts the osmotic pressure to 0 MPa, temporarily maintaining a state of no head pressure.

[0030] In this embodiment, the air pressure regulating valve 7 of the air pressure pipeline can be adjusted to make the air pressure value of the air pressure gauge 13 at the top of the soil storage bin 1 reach 0.2-0.3 MPa, ensuring that the pressure environment of the soil bin during actual shield tunneling is met.

[0031] In this embodiment, the spiral drive motor 4 is started to control the spiral rod 5 to discharge slag, and the gate set at the slag outlet 17 is opened. The discharge of the slag and soil discharge device and the advancement speed of the hydraulic cylinder in the slag adding system are adjusted by controlling the frequency of the spiral drive motor 4 to achieve a dynamic balance between slag discharge and slag adding, thereby simulating the shield tunneling face excavation process and the spiral slag discharge process.

[0032] In this embodiment, while simulating the excavation process, the osmotic pressure simulated by the osmotic adjustment module is increased step by step during the adjustment process, and the osmotic pressure is increased step by step from 0kPa, with an increase gradient of 10kPa. The specific osmotic pressure gradient can also be adjusted according to demand. At the same time, observe whether the slag at the slag outlet 17 has a slag gushing phenomenon. If there is a gushing or mud and sand gushing phenomenon, record the osmotic pressure value at this time. The step-by-step increase can observe the behavior changes of the slag more carefully, gradually approach the critical state, and more clearly observe the relationship between the osmotic pressure and the gushing phenomenon, so as to more accurately judge the critical permeability coefficient.

[0033] In this embodiment, different improved proportions of improved slag can be used in combination with a permeameter for permeability tests, and its permeability coefficient can be measured in combination with the recorded permeability pressure. When the shield passes through water-rich sand layers at different burial depths, the shield soil bin and the water head pressure at the face are changing dynamically. Therefore, the critical permeability coefficient of slag bursting under different burial depth conditions can be obtained by conducting a permeability test and combining the device for testing. Select appropriate improved materials and methods to ensure that the permeability coefficient of the improved slag is lower than the critical value, thereby effectively avoiding the occurrence of bursting and ensuring construction safety.

[0034] In summary, the present invention provides a simulation test device for earth pressure balance shield construction in water-rich sand layers, which can highly simulate the complex working conditions of shield tunneling under water-rich sand layer conditions through the slag discharge and slag addition processes of the slag discharge system and the slag addition system, accurately capture the changes in the physical and mechanical properties of the soil during the earth pressure balance process, and at the same time, according to the required working conditions, adjust the internal air pressure and seepage pressure by adjusting the pressure regulating system to simulate the adjustment of the air pressure at different burial depths and the water head pressure value of the shield machine at different burial depths or different hydrological conditions. It can more intuitively judge whether the improved slag will erupt, and can more accurately predict the risk of eruption, providing scientific and forward-looking guidance for construction personnel, helping to take measures in advance and effectively prevent the occurrence of eruption disasters. At the same time, combined with the permeability test, the critical permeability coefficient of eruption of slag under different burial depths can be obtained. The structural design of the present invention is compact and easy to operate, so that efficient and accurate model tests can be carried out in the shield construction preparation stage, which not only improves the test efficiency before construction, but also provides strong support for the optimization and adjustment of the construction plan, and helps to save raw materials to the maximum extent while ensuring the safe excavation of the shield, and improve the economic benefits and environmental friendliness of the project. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0035] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A simulation test device for earth pressure balance shield construction in water-rich sand layer, characterized in that: include: A soil storage bin, the interior of which is used to load improved slag; A slag discharge system, the slag discharge system comprising a slag discharge pipe and a slag discharge device, the slag discharge pipe is provided with a slag discharge port, and the slag discharge device transfers the slag in the soil storage bin to the slag discharge port for discharge; A slag adding system, the slag adding system comprises a slag adding pipeline and a slag adding regulating module, the slag adding pipeline is connected with the soil storage bin, a slag adding port is provided on the slag adding pipeline, and the slag adding regulating module drives the slag in the slag adding pipeline to enter the soil storage bin; The simulated pressure regulating system includes a pressure control module, an air pressure regulating module and an osmosis regulating module. The pressure control module is connected to the air pressure regulating module and the osmosis regulating module. The air pressure regulating module is connected to the soil storage bin. The osmosis regulating module is connected to the slag adding pipeline.

2. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 1 is characterized by: The wall of the soil storage bin is formed by welding steel plates.

3. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 1 is characterized by: The slag and soil discharge device comprises a spiral drive motor and a spiral rod. The spiral rod is arranged inside the slag and soil discharge pipe. The spiral drive motor drives the spiral rod to rotate and discharge soil.

4. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 1, characterized in that: The air pressure regulating module includes an air pressure regulating pipeline and an air pressure pipeline pressure regulating valve. One end of the air pressure regulating pipeline is connected to the soil storage bin, and the other end of the air pressure regulating pipeline is connected to the pressure control module. The air pressure pipeline pressure regulating valve is installed on the air pressure regulating pipeline.

5. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 4, characterized in that: The osmotic regulation module includes a water storage tank, an osmotic diversion pipeline, an osmotic pressure regulating pipeline and an osmotic pipeline pressure regulating valve; The water storage tank and the slag adding pipeline are connected via the permeation diversion pipeline, the water storage tank and the pressure control module are connected via the permeation pressure regulating pipeline, and the permeation pipeline pressure regulating valve is installed on the permeation pressure regulating pipeline.

6. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 5, characterized in that: The pressure control module includes an air compressor.

7. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 1, characterized in that: A barometer is provided on the top of the soil storage bin, and the barometer is used to display the air pressure value in the soil storage bin.

8. The simulation test device for earth pressure balance shield construction in water-rich sand layer according to claim 1, characterized in that: The slag adding control module comprises a sealed bulldozer piston, a slag adding driving member and a reaction wall; The sealed bulldozer piston is movably arranged inside the slag adding pipeline, the reaction wall is fixedly arranged outside the slag adding pipeline, the slag adding driving member is installed on the reaction wall, and the slag adding driving member pushes the sealed bulldozer piston to move in the slag adding pipeline.

9. A test method for a simulation test device for earth pressure balance shield construction in water-rich sand layer, characterized in that: include: Pre-load the improved slag into the soil storage bin and the slag feeding pipeline; According to the actual air pressure environment of the shield machine at different buried depths, the air pressure value in the soil storage bin is simulated and adjusted through the pressure control module and the air pressure regulating module in the pressure regulating system; Start the slag discharge system and slag feeding system. In the slag discharge system, the slag is discharged through the slag discharge and soil discharge device. In the slag feeding system, the slag is added through the slag feeding control module to achieve a dynamic balance between slag discharge and slag feeding, and simulate the shield tunneling face excavation process and the spiral slag discharge process; While simulating the excavation process, the internal seepage pressure is regulated by the pressure control module and the seepage regulation module in the simulated pressure regulation system, and the head pressure value of the tunnel boring machine at different burial depths or different hydrological conditions is simulated. At the same time, the slag discharge at the slag outlet is observed to determine whether gushing occurs. If gushing or mud and sand bursts occur, the seepage pressure value is recorded.

10. The test method of the simulation test device based on the earth pressure balance shield construction in water-rich sand layer according to claim 9, characterized in that: During the regulation process, the osmotic pressure simulated by the osmotic regulation module is increased step by step, and the osmotic pressure is increased step by step from 0 kPa with an increase gradient of 10 kPa.

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