A slurry shield tunneling device and method suitable for super gravity simulation

Abstract

The present invention discloses a slurry shield excavation device and method suitable for super gravity simulation. The shield body and the slag feeding and discharging system are fixed by a bottom plate and placed on a geotechnical centrifuge. The soil box and the shield power system are connected by the shield body, and the shield body is connected to the slag feeding and discharging system. The front partition divides the working cabin into a slurry cabin and an air cushion cabin. One end of the main shaft passes through the slurry cabin and the air cushion cabin in sequence and is connected to the cutter head, and the other end is connected to the driving motor; one end in the cabin shell is movably connected to the opening of the soil box, and the other end is fixedly connected to the power box. The slag feeding and discharging system is used to transport mud in the working cabin and discharge mud. A pressure maintaining system is provided inside the cabin shell, and the pressure maintaining system is used to control the gas pressure in the air cushion cabin. The present invention can restore the stress level of the actual soil and simulate the excavation process of the actual slurry shield. Through the excavation parameters, mud pressure and soil response law during the excavation process, a theoretical basis is provided for the construction of deep buried and cross-sea tunnels.

Description

Technical Field

[0001] The invention belongs to the field of slurry shield model test, and in particular relates to a slurry shield tunneling device and method suitable for super gravity simulation. Background Art

[0002] As a commonly used excavation equipment in cross-sea and cross-river tunnel projects, the slurry shield uses mud pressure to press the mud out of the shield body and form a mud film in the stratum in front of the excavation face, so that the mud pressure acts on the mud film in the form of surface force and reaches a balance with the soil and water pressure of the stratum in front, preventing the collapse of the excavation face. As the slurry shield continues to advance forward, the stratum in front of the excavation face and the formed mud film are continuously cut by the cutter on the cutter head, and at the same time, the mud will penetrate into the stratum to form a new mud film. Different shield cutter head speeds, advancement speeds, mud pressures and stratum types will change the formation process of the mud film, and then affect the stability of the excavation face and the settlement and deformation of the soil around the shield during the excavation process. Therefore, how to determine the excavation parameters (i.e., cutter head speed, advancement speed, mud pressure, etc.) of the slurry shield under deep burial and high water pressure conditions, and then control the stability of the excavation face and soil disturbance is an urgent problem to be solved. At present, most of the model devices of slurry shield can only be used under normal gravity (i.e., 1g conditions). For example, the slurry shield excavation test device proposed in CN117782656A can only simulate the shield excavation process under normal gravity, and cannot restore the soil and water stress levels in actual projects, resulting in the shield excavation process, support pressure, and soil response obtained in the test being inconsistent with the actual situation. The ultra-gravity centrifugal simulation technology has a scale effect and can effectively restore the stress level of the soil at a certain buried depth in the actual project. Existing studies have proposed to carry out mud infiltration tests under ultra-gravity, such as the three-dimensional dynamic mud penetration test device under ultra-gravity proposed in CN116297105B, which can restore the stress level of the actual soil and inject mud into the soil layer to explore the formation law of mud film. However, the existing devices cannot simulate the actual shield's cutterhead cutting, forward advancement, mud pressure, and inlet and outlet flow control under ultra-gravity. In addition, mud is mainly composed of a certain mass of bentonite and water. Under supergravity conditions, due to the different densities of water and soil, the mud will segregate (that is, water and bentonite particles will separate), resulting in uneven mud density, and thus unable to simulate mud film formation and actual mud penetration laws. Summary of the invention

[0003] In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a slurry shield excavation device and method suitable for super gravity simulation, so as to provide an experimental basis for simulating the entire shield excavation process under deep burial depth and high water pressure conditions, especially for deep underground and cross-sea tunnel excavation projects.

[0004] The scheme adopted by the present invention is as follows:

[0005] 1. A slurry shield tunneling device suitable for super gravity simulation:

[0006] It includes a shield tunneling module, a geotechnical centrifuge and a remote control system; the shield tunneling module is placed on the geotechnical centrifuge, the shield tunneling module is connected to the remote control system, the shield tunneling module includes a soil box, a shield body, a shield power system and a slurry inlet and discharge system, the soil box and the shield power system are connected through the shield body, the shield body is also connected to the slurry inlet and discharge system, the soil box, the shield power system and the slurry inlet and discharge system are all fixedly connected to a base, and the base is placed on the hanging basket of the geotechnical centrifuge.

[0007] The shield body includes a hull with a working cabin inside, a cutterhead, an annular front baffle and a main shaft; the front baffle is located inside the hull and divides the working cabin into a mud and water cabin and an air cushion cabin, the cutterhead is located on the side close to the mud and water cabin, one end of the main shaft is connected to the shield power system, and the other end of the main shaft passes through the air cushion cabin, the front baffle and the mud and water cabin in sequence and is coaxially connected to the cutterhead; one end of the hull with the mud and water cabin is movably connected to the opening of the soil box so as to be movable forward and backward, and one end of the hull with the air cushion cabin is fixedly connected to the shield power system, the shield power system is used to drive the cutterhead to rotate, and at the same time drive the main shaft to excavate forward along its own axial direction, and the mud and water cabin and the cutterhead are both arranged at the opening position of the soil box; a pressure maintaining system is provided inside the hull, and the pressure maintaining system is used to control and adjust the gas pressure in the air cushion cabin.

[0008] The slurry inlet and discharge system comprises a mud pump, a mud water tank, a slurry inlet pipe 1, a slurry inlet pipe 2, an overflow pipe, a bypass pipe, a spiral drive motor, a slurry discharge pipe, a separation box and a slag box; the mud pump, the mud water tank, the separation box and the slag box are all placed on a base, the mud pump is connected to the output end of the mud water tank, the mud pump is communicated with the mud water tank through the slurry inlet pipe 1, the mud pump is communicated with the air cushion cabin through the slurry inlet pipe 2, the slurry inlet pipe 1 and the slurry inlet pipe 2 are respectively provided with a solenoid valve 2 and a solenoid valve 3, an overflow pipe is provided at a position 4 / 5 of the height of the mud water tank, the two ends of the overflow pipe are respectively conducted with the mud water tank and the atmosphere, the overflow pipe is provided with a solenoid valve 1, a bypass pipe is also provided between the mud pump and the mud water tank, one end of the bypass pipe is connected to the mud water tank, and the other end is respectively communicated with the mud pump, the slurry inlet pipe 1 and the slurry inlet pipe 2, and a solenoid valve 4 is provided on the bypass pipe;

[0009] A slurry discharge pipe opening is provided at the bottom of the front partition, one end of the slurry discharge pipe passes through the slurry discharge pipe opening and is connected with the mud and water tank, the other end of the slurry discharge pipe is connected with one end of the separation box through a pipeline, and a solenoid valve five is provided on the pipeline from the slurry discharge pipe to the separation box, the other end of the separation box is connected with the slag box through a switching valve group, and the other end of the slurry discharge pipe is also connected to the output shaft of the spiral drive motor, and the spiral drive motor is used to drive the slurry discharge pipe to rotate.

[0010] The pressure maintaining system comprises an air intake pipe, an exhaust pipe, a pressure transmitter, an air intake regulating valve, an exhaust regulating valve and an electronic control system; an air intake port and an air outlet port are provided in the end of the cabin shell close to the shield power system, one end of the air intake pipe is connected with the air cushion cabin after passing through the air intake port, the other end of the air intake pipe is connected with an external air source, one end of the exhaust pipe is connected with the air cushion cabin after passing through the exhaust port, and the other end of the exhaust pipe is connected with the outside atmosphere; an air intake regulating valve and an exhaust regulating valve are respectively provided on the air intake pipe and the exhaust pipe, a pressure transmitter is installed in the air cushion cabin, the pressure transmitter is used to measure the gas pressure in the air cushion cabin, the pressure transmitter, the air intake regulating valve and the exhaust regulating valve are all connected to the electronic control system, the pressure transmitter transmits the gas pressure signal collected in real time to the electronic control system, and the electronic control system regulates the air intake regulating valve and the exhaust regulating valve by comparing the preset air pressure value with the actual air pressure value collected, so that the gas pressure in the air cushion cabin is maintained at the preset air pressure value.

[0011] A centrifugal drum type active separator and a vertical filter are arranged inside the separation box. The slurry outputted from the slurry discharge pipe flows into the separation box from the input end of the centrifugal drum type active separator, is filtered by the centrifugal drum type active separator and the vertical filter in turn, and then flows out of the separation box. The aperture size of the flow channel of the centrifugal drum type active separator and the aperture size of the vertical filter mesh are both smaller than the maximum particle size that can pass through the switching valve group. The input pipe and the output pipe connected to the separation box are both located at the top of the separation box, and the horizontal heights of the input pipe and the output pipe of the separation box are consistent with the horizontal height of the slurry discharge pipe. The centrifugal drum type active separator is externally connected to a motor.

[0012] The remote control system includes a speed regulating propulsion module and a pressure regulating propulsion module, which are respectively connected to the propulsion cylinder and the mud pump in the shield power system; the speed regulating propulsion module is used to control the forward speed of the propulsion cylinder, thereby controlling the excavation speed of the shield body, and the pressure regulating propulsion module is used to control the pumping pressure and flow of the mud in the mud pump. The speed regulating propulsion module includes a filter, a one-way valve and a servo valve, one end of the filter is connected to the first port of the rotary joint, the other end of the filter is connected to one end of the propulsion cylinder after passing through the one-way valve and the servo valve in sequence, and the other end of the propulsion cylinder is connected to the second port of the rotary joint; the pressure regulating propulsion module includes an electromagnetic ball valve, a pressure reducing valve, a reversing valve, a proportional speed regulating valve and a gear flowmeter, one end of the electromagnetic ball valve is connected to the third port of the rotary joint, the other end of the electromagnetic ball valve is connected to one end of the mud pump after passing through the pressure reducing valve, the reversing valve, the proportional speed regulating valve and the gear flowmeter in sequence, the other end of the mud pump is connected to the fourth port of the rotary joint, and the rotary joint is externally connected to a power supply.

[0013] The slurry discharge pipe includes a spiral core shaft, spiral blades, an outer tube, a discharge inlet, a discharge outlet and a reducer; the spiral blades are in the shape of concentric annular spirals, the spiral blades are coaxially connected to the outer side wall of the spiral core shaft and connected to form an integral shaftless spiral, the shaftless spiral is arranged inside the outer tube, a discharge inlet and a discharge outlet are respectively provided at both ends of the outer tube, the discharge inlet and the discharge outlet of the outer tube are respectively connected to the mud and water tank and the separation box, one end of the shaftless spiral close to the discharge outlet is connected to the output shaft of the spiral drive motor, and a reducer is installed between the side of the shaftless spiral close to the discharge outlet and the spiral drive motor.

[0014] The switching valve group is mainly composed of two branch pipes, a slag inlet pipe and a slag outlet pipe. One end of the slag inlet pipe is connected to the separation box, and the other end of the slag inlet pipe is respectively connected to the input ends of the two branch pipes. The output ends of the two branch pipes are connected to one end of the slag outlet pipe, and the other end of the slag outlet pipe is connected to the slag box. An electromagnetic valve six and a damping one are arranged on one branch pipe, and an electromagnetic valve seven and a damping two are arranged on the other branch pipe. An electromagnetic flowmeter is arranged on the slag outlet pipe.

[0015] 2. A slurry shield tunneling method suitable for super gravity simulation, comprising the following steps:

[0016] Step 1: Under normal gravity conditions, remove the soil box from the base, seal the openings on the side walls of the soil box with aluminum plates, and then prepare soil samples in layers in the soil box and bury sensors in the soil samples;

[0017] Step 2: Use a saturation box to saturate the soil sample in the soil box. When the soil sample is saturated, use a crane to lift the soil box as a whole to the base and fix it. Then lift the installed shield tunneling module into the second basket of the geotechnical centrifuge and fix it. Connect the sensor, torque sensor, propulsion cylinder and mud pump in the soil sample to the remote control system.

[0018] Step 3: Prepare mud with a preset ratio of bentonite and water, then inject the mud into the mud water tank, push the shield and the cutter head into the hole of the soil box, close the mud discharge pipe, and continue to inject mud into the working cabin through the mud pump. When the mud water tank is full of mud and the liquid level in the air cushion cabin reaches 2 / 3 of the cabin shell diameter, proceed to step 4;

[0019] Step 4: Continue to inject mud. When mud seeps out of the overflow pipe, close the solenoid valve 1, and then open the pressure-maintaining system to adjust the air pressure in the air cushion cabin so that the overall mud pressure is higher than the lateral water and soil pressure of the soil sample. Then remove the aluminum plate sealed at the hole of the soil box to allow the pressurized mud to penetrate into the soil sample and form a mud film in the soil layer in front.

[0020] Step 5: Start the geotechnical centrifuge, control the shield to cut forward, and obtain the soil response law during the shield excavation process based on the sensors in the soil box;

[0021] Step 6: When the shield reaches the preset excavation distance, stop excavation, close the slurry inlet and outlet pipelines, control the air pressure in the air cushion cabin to gradually decrease or increase, and realize active or passive destruction of the shield excavation surface. At the same time, according to the changes in soil and water pressure in the soil ahead and the mud pressure in the mud water cabin, determine the limit support pressure, and then obtain the stability law of the slurry balance shield excavation surface.

[0022] The specific steps of step 5 are as follows:

[0023] Step 5.1: Start the geotechnical centrifuge. When the centrifugal acceleration Ng increases, close the electromagnetic valve 2 and the electromagnetic valve 3 on the slurry inlet pipe (28, 29) and the electromagnetic valve 5 on the slurry discharge pipeline, control the pressure-maintaining system to feed air into the air cushion cabin, so that the mud fills the mud water tank, and the mud pressure in the mud water tank is equal to the lateral pressure of the soil and water outside the cutter disc; turn on the mud pump and the electromagnetic valve 4, so that the mud circulates in the bypass pipe to prevent segregation and precipitation, and at the same time turn on the stirring motor in the mud water tank so that the stirring rod stirs the mud to prevent the mud from segregating;

[0024] Step 5.2: When the centrifugal acceleration of the geotechnical centrifuge reaches the preset Ng and lasts for the preset time, the solenoid valve 4 is closed, the pressure-maintaining system controls the air pressure in the air cushion cabin to remain unchanged, and the solenoid valve 2 of the slurry inlet pipeline and the solenoid valve 5 of the slurry discharge pipeline are opened; at the same time, the switching valve group is started according to the preset damping, and the mud and slag will be driven by the pressure difference between the mud and water cabin and the slag box, and transported to the separation box through the spiral blades in the slurry discharge pipe, and then the slag particles are separated and filtered through the separation box, and then enter the slag box;

[0025] Step 5.3: According to the preset excavation speed, cutter head speed and slurry flow rate, the remote control system is used to control the propulsion cylinder and mud pump so that the shield body cuts forward and advances. The soil response law during the shield excavation process is obtained based on the sensors installed in the soil box.

[0026] The technical solution principle of the present invention is as follows:

[0027] For prototype soil sample: σ=ρgh

[0028] For a 1 / N times scaled model: σ 1 =ρ·g·h / N

[0029] For a 1 / N times scaled model under N times hypergravity: σ 2 =ρ·Ng·h / N=ρgh

[0030] Among them, σ represents the stress of the prototype soil sample, ρ represents the natural density of the soil, g represents the gravitational acceleration, h represents the depth of the formation, and σ 1 represents the stress of the 1 / N-fold scale model, σ 2 It represents the stress of 1 / N times scaled model under N times hypergravity, where N represents the ratio of centrifugal acceleration of geotechnical centrifuge to gravitational acceleration;

[0031] It is easy to see that σ=σ 2 , that is, the stress level of the prototype soil sample is equal to that of the 1 / N times scaled model under N times hypergravity, that is, the stress field of the prototype can be replicated under hypergravity, thereby greatly improving the similarity of the slurry shield tunneling test.

[0032] The above design can restore the stress level of the actual soil and simulate the excavation process of the actual slurry shield. Through the excavation parameters, slurry pressure and soil response law during the excavation process, the excavation process of the shield under complex geological conditions such as homogeneous sand, consolidated soft clay, confined water layer, gas-bearing layer and the instability disaster of the shield excavation face can be studied, and the shield shutdown pneumatic support working condition can also be restored. At the same time, it provides an experimental basis for studying the interaction between water, soil and tunneling machine under high water pressure and high ground stress conditions, safety control theory, and the influence law and control technology of shield excavation on stratum disturbance under high water pressure and high ground stress conditions.

[0033] In the slurry shield excavation device, the variable frequency motor drives the main shaft and the cutterhead to rotate; the oil cylinder applies thrust to the power box, and through the guide rail, the power box drives the main shaft and the shield body to advance into the soil box. The front partition divides the shield into a slurry tank and an air cushion tank. The mud pump transports the mud to the slurry tank, and the mud and slag are transported to the slag box through the screw machine and the damping pipe under the pressure difference between the mud and water tank and the slag box. The pressure holding system is connected to the air cushion tank, and the air is introduced into and exhausted from the air cushion tank to regulate the mud pressure. The hydraulic system is connected to the mud pump and the oil cylinder to regulate the slurry flow rate, propulsion force and speed. The loading and control system controls the cutterhead speed, shield thrust and speed, slurry flow rate and air pressure of the air cushion tank in real time. The present invention can restore the stress level of the actual soil and simulate the excavation process of the actual slurry shield. Through the excavation parameters, mud pressure and soil response law during the excavation process, it provides a theoretical basis for the construction of deep buried and cross-sea tunnels.

[0034] The beneficial effects of the present invention are:

[0035] 1. The present invention utilizes the hypergravity environment to restore the actual stress level of the soil. Through the shield tunneling module, it can simulate the actual shield cutter cutting, forward tunneling, the size and distribution of the slurry pressure in the shield body, and the control of the slurry inlet and outlet flow.

[0036] 2. The present invention can prevent the mud from being separated and precipitated in the shield body in a hypergravity environment and simulate the mud film formation process in an actual shield by arranging a stirring motor and a stirring rod in the mud water tank and a mud stirring rod on the back of the cutter head.

[0037] 3. The present invention can transport the cut debris and the mud in the mud and water tank to the separation box by arranging a screw conveyor and blades in the slurry discharge pipeline; the large debris particles can be filtered through the separator and filter screen in the separation box to prevent the damping valve group from being blocked; through the damping valve group, the mud can be driven by the pressure difference between the mud and water tank and the debris box and transported to the debris box at the required slurry discharge flow rate, thereby realizing the slurry discharge flow control of the device.

[0038] 4. The present invention utilizes the similarity of the hypergravity test. The slurry shield device designed by the present invention can simulate the slurry shield excavation process in actual engineering projects, obtain the soil disturbance mechanism during the excavation process, the active / passive instability and failure mechanism of the excavation face, and the ultimate support pressure, and provide a theoretical basis for deep underground and cross-sea tunnel excavation projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a structural diagram of the device of the present invention;

[0040] Figure 2 A top view of the device of the present invention;

[0041] Figure 3 It is a schematic diagram of the internal structure of the tunneling support system of the present invention;

[0042] Figure 4 is a side view of the device of the present invention;

[0043] Figure 5 It is a schematic diagram of the internal pipelines of the slurry inlet and outlet system of the present invention;

[0044] Figure 6 It is a schematic diagram of the structure of the mud water tank of the present invention;

[0045] Figure 7 It is a schematic diagram of a separation box of the present invention;

[0046] Figure 8 It is a schematic diagram of a slurry discharge pipe of the present invention;

[0047] Fig. 9 It is a schematic diagram of the pressure-maintaining system of the present invention;

[0048] Fig.10 It is a schematic diagram of the hydraulic system of the present invention;

[0049] Fig.11 It is a schematic diagram of the ultragravity centrifuge experimental platform of the present invention;

[0050] In the figure: 1. Soil box; 2. Base; 3. Mud and water tank; 4. Frequency conversion motor; 5. Mud pump; 6. Shield power system; 7. Muck box; 8. Screw drive motor; 9. Separation box; 10. Shield; 11. Power box; 12. Cutter head; 13. Mud and water tank; 14. Front partition; 15. Air cushion cabin; 16. Shaftless screw; 17. Main shaft; 18. Torque sensor; 19. Propulsion cylinder; 20. Intake pipe; 21, exhaust pipe; 22, electromagnetic flowmeter; 23, switching valve group; 24, pressure maintaining system; 25, overflow pipe; 26, solenoid valve 1; 27, connecting pipe; 28, slurry inlet pipe 1; 29, slurry inlet pipe 2; 30, solenoid valve 2; 31, solenoid valve 3; 32, solenoid valve 4; 33, bypass pipe; 34, solenoid valve 5; 35, solenoid valve 6; 36, solenoid valve 7; 37, damping 1; 38, damping 2; 39. Slurry discharge pipe; 42. Geotechnical centrifuge; 43. First hanging basket; 44. Counterweight; 45. Swivel arm; 46. Second hanging basket; 47. Remote control system; 48. Ball guide; 49. Centrifugal drum active separator; 50. Vertical filter screen; 51. Reducer; 52. Spiral mandrel; 53. Outer pipe; 54. Discharge inlet; 55. Discharge outlet; 56. Observation window; 57. Connecting flange; 58. Spiral blade; 59. Aluminum plate; 60. Motor; 61. Electronic control system; 62. Inlet regulating valve; 63. Exhaust regulating valve; 64. Pressure transmitter; 65. Stirring rod; 67. Rotary joint; 68. Filter; 69. Check valve; 70. Servo valve; 71. Solenoid ball valve; 72. Pressure reducing valve; 73. Reversing valve; 74. Proportional speed regulating valve; 75. Gear flowmeter; 76. Stirring motor. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0052] like Figure 1 and Fig.11 As shown, the device includes a shield tunneling module, a geotechnical centrifuge 42 and a remote control system 47; the shield tunneling module is placed on the geotechnical centrifuge 42, and the shield tunneling module is connected to the remote control system 47. The shield tunneling module includes a soil box 1, a shield body 10, a shield power system 6 and a slurry inlet and outlet system. A vertical aluminum plate 59 is provided on the side of the soil box 1 facing the shield body 10, and the aluminum plate 59 is used to support the soil in the soil box 1. The soil box 1 and the shield power system are connected through the shield body 10, and the shield body 10 is also connected to the slurry inlet and outlet system. The soil box 1, the shield power system and the slurry inlet and outlet system are all fixedly connected to the base 2, and the base 2 is placed on the hanging basket of the geotechnical centrifuge 42.

[0053] In a specific implementation, the geotechnical centrifuge 42 includes a first hanging basket 43, a second hanging basket 46 and a centrifuge base; the first hanging basket 43 and the second hanging basket 46 are fixedly mounted on both sides of the centrifuge base through a rotating arm 45, respectively, and the shield tunneling module is integrally mounted inside the second hanging basket 46. A counterweight 44 is placed inside the first hanging basket 43 to balance the weight of the test device. When the geotechnical centrifuge 42 is rotating, the hanging baskets 43 and 46 gradually become horizontal, and the shield tunneling module starts to work during the rotation of the geotechnical centrifuge 42.

[0054] like Figure 3 As shown, the shield body 10 includes a cabin with a working cabin inside, a cutter head 12, an annular front partition 14 and a main shaft 17; the aluminum plate 59 is installed at the opening of the soil box 1, the front partition 14 is located inside the cabin shell and divides the working cabin inside the cabin shell into two parts: a mud and water cabin 13 and an air cushion cabin 15, the mud and water cabin 13 is located on the side close to the soil box 1, the air cushion cabin 15 is located on the side close to the shield power system, the cutter head 12 is located on the side close to the mud and water cabin 13, one end of the main shaft 17 is connected to the shield power system, and the other end of the main shaft 17 is sequentially passed through the air cushion cabin 15 and the middle of the front partition 14. The through hole and the mud and water tank 13 are coaxially connected to the cutter head 12; one end of the mud and water tank 13 is movably connected to the opening of the soil box 1 in the cabin shell, and one end of the air cushion cabin 15 is fixedly connected to the output shaft of the variable frequency motor 4 of the shield power system. The shield power system is used to drive the cutter head 12 to rotate and drive the main shaft 17 to dig forward along its own axis. The mud and water tank 13 and the cutter head 12 are both set at the opening position of the soil box 1; a pressure maintaining system 24 is set inside the cabin shell, and the pressure maintaining system 24 is used to control and adjust the gas pressure in the air cushion cabin 15. A connecting pipe 27 is also set between the mud and water tank 13 and the air cushion cabin 15, and the mud in the mud and water tank 13 enters the air cushion cabin 15 through the connecting pipe 27.

[0055] like Figure 2 and Figure 4 As shown, the shield power system 6 includes a variable frequency motor 4, a torque sensor 18, a power box 11, a thrust cylinder 19 and a ball guide 48; the ball guide 48 is fixed to the upper surface of the base 2, the thrust cylinder 19 can be installed on the ball guide 48 for reciprocating motion along the extension direction of the ball guide 48, the power box 11 is fixedly installed on the thrust cylinder 19, the variable frequency motor 4 and the torque sensor 18 are both arranged inside the power box 11, the side wall of the power box 11 is fixedly connected to one end of the cabin shell, an opening is provided on the side wall of the power box 11 close to the shield body 10 as a power box outlet, one end of the main shaft 17 is passed through the power box outlet and connected to the output shaft of the variable frequency motor 4, and a torque sensor 18 is provided on the outer surface of the main shaft 17 close to the variable frequency motor 4; the torque sensor 18 is connected to the remote control system 47, and the torque sensor 18 transmits the collected torque signal to the remote control system 47.

[0056] The variable frequency motor 4 is connected to a remote control system 47, and the remote control system 47 controls the speed of the variable frequency motor 4. The variable frequency motor 4 drives the cutter head 12 to rotate through the main shaft 17. During the test, the torque sensor 18 is used to obtain the rotation parameters of the cutter head 12 in real time. The power box 11 moves forward on the ball guide rail 48 through the thrust provided by the propulsion cylinder 19, and drives the shield body 10 to move horizontally.

[0057] like Figure 5 As shown, the slurry inlet and discharge system includes a slurry pump 5, a slurry water tank 3, a slurry inlet pipe 1 28, a slurry inlet pipe 29, an overflow pipe 25, a bypass pipe 33, a screw drive motor 8, a slurry discharge pipe 39, a separation box 9 and a slag box 7; the slurry pump 5, the slurry water tank 3, the separation box 9 and the slag box 7 are all placed on the base 2, the slurry water tank 3 is used to store slurry, the slurry pump 5 is connected to the output end of the slurry water tank 3, the slurry pump 5 is connected to the slurry water tank 13 through the slurry inlet pipe 1 28, the slurry pump 5 is connected to the air cushion cabin 15 through the slurry inlet pipe 29, and the slurry inlet The first pipe 28 and the second slurry inlet pipe 29 are respectively provided with a second solenoid valve 30 and a third solenoid valve 31. An overflow pipe 25 is provided at a position 4 / 5 of the height of the mud and water tank 13. Both ends of the overflow pipe 25 are respectively connected to the mud and water tank 13 and the atmosphere. The overflow pipe 25 is provided with a first solenoid valve 26. A bypass pipe 33 is also provided between the mud pump 5 and the mud and water tank 3. One end of the bypass pipe 33 is connected to the mud and water tank 3, and the other end is respectively connected to the mud pump 5, the first slurry inlet pipe 28 and the second slurry inlet pipe 29. The bypass pipe 33 is provided with a fourth solenoid valve 32.

[0058] A slurry discharge pipe opening is provided at the bottom of the front partition 14, one end of the slurry discharge pipe 39 passes through the slurry discharge pipe opening and is connected with the mud and water tank 13, the other end of the slurry discharge pipe 39 is connected with one end of the separation box 9 through a pipeline, and a solenoid valve 5 34 is provided on the pipeline from the slurry discharge pipe 39 to the separation box 9, the other end of the separation box 9 is connected with the slag box 7 through the switching valve group 23, and the other end of the slurry discharge pipe 39 is also connected to the output shaft of the spiral drive motor 8, and the spiral drive motor 8 is used to drive the slurry discharge pipe 39 to rotate.

[0059] The mud pump 5 is used to drive the mud in the mud water tank 3, and input it into the mud water tank 13 and the air cushion tank 15 through the mud inlet pipe 1 28 and the mud inlet pipe 2 29 respectively. The slurry discharge pipe 39 is connected to the mud water tank 13 but not connected to the air cushion tank 15. The slag and excess mud generated during the shield excavation process are discharged to the separation box 9 through the screw drive motor 8, and then the separation box 9 separates the largest particles that exceed the damping valve group (damping 37, 38) that can pass through, and finally enters the slag box 7. The damping 37, 38 between the separation box 9 and the slag box 7 can control the slurry discharge flow rate and play a role in reducing the pressure drop. The flow rate flowing into the slag box 7 is obtained through the electromagnetic flowmeter 22.

[0060] like Figure 6As shown, a stirring motor 76 and a stirring rod 65 are provided inside the mud water tank 3, and the stirring rod 65 is connected to the stirring motor 76, so as to prevent the mud in the mud water tank 3 from being separated and precipitated and the density of the transported mud from being uneven; a stirring rod is provided behind the cutter disc 12 and extends into the mud water tank 13, so as to prevent the mud in the mud water tank 13 from being separated and precipitated by stirring, and at the same time, a tool is provided in front of the cutter disc 12 for cutting the soil.

[0061] like Fig. 9 As shown, the pressure-maintaining system 24 includes an air inlet pipe 20, an exhaust pipe 21, a pressure transmitter 64, an air inlet regulating valve 62, an exhaust regulating valve 63 and an electronic control system 61; an air inlet and an air outlet are provided at the end of the hull near the shield power system, one end of the air inlet pipe 20 passes through the air inlet and is connected to the air cushion cabin 15, the other end of the air inlet pipe 20 is connected to an external air source, one end of the exhaust pipe 21 passes through the exhaust port and is connected to the air cushion cabin 15, and the other end of the exhaust pipe 21 is connected to the outside atmosphere; the air inlet regulating valves 62 and 63 are provided on the air inlet pipe 20 and the exhaust pipe 21, respectively. 2 and exhaust regulating valve 63, a pressure transmitter 64 is installed in the air cushion cabin 15, the pressure transmitter 64 is used to measure the gas pressure in the air cushion cabin 15, the pressure transmitter 64, the air intake regulating valve 62 and the exhaust regulating valve 63 are all connected to the electronic control system 61, the pressure transmitter 64 transmits the real-time collected gas pressure signal to the electronic control system 61, the electronic control system 61 regulates the air intake regulating valve 62 and the exhaust regulating valve 63 by comparing the preset air pressure value with the collected actual air pressure value, so that the gas pressure in the air cushion cabin 15 is maintained at the preset air pressure value.

[0062] The pressure-maintaining system 24 has an adaptive adjustment function, and automatically balances the air pressure in the air cushion cabin 15 by monitoring the pressure; it is connected to the inside of the air cushion cabin 15 through an air pipe, and its components are controlled and adjusted in real time by the electronic control system, so as to control the air pressure in the shield body 10. The pressure-maintaining system 24 monitors the gas pressure above the liquid level of the air cushion cabin 15, and controls the intake and discharge amount of compressed gas by using the intake pipe 20 and the exhaust pipe 21, so as to set the gas pressure in the air cushion cabin 15. Specifically, the pressure transmitter 64 is used to measure the air pressure in the air cushion cabin 15 in real time and feed it back to the electronic control system 61 through an electrical signal, and the intake and discharge amount of the intake pipe 20 and the exhaust pipe 21 are regulated by the electronic control system 61. When the pressure in the air cushion cabin 15 is less than the preset air pressure setting value, the intake regulating valve 62 of the intake pipe 20 is opened to intake air into the air cushion cabin 15; when the pressure in the air cushion cabin 15 is greater than the air pressure setting value, the exhaust regulating valve 63 of the exhaust pipe 21 is opened to exhaust air from the air cushion cabin 15.

[0063] like Figure 7As shown, a centrifugal drum type active separator 49 and a vertical filter screen 50 are arranged inside the separation box 9. The slurry outputted from the slurry discharge pipe 39 flows into the separation box 9 from the input end of the centrifugal drum type active separator 49, and is filtered by the centrifugal drum type active separator 49 and the vertical filter screen 50 in turn before flowing out of the separation box 9. The aperture size of the flow channel of the centrifugal drum type active separator 49 and the aperture size of the mesh of the vertical filter screen 50 are both smaller than the maximum particle size that the switching valve group 23 can pass. The input pipe and the output pipe connected to the separation box 9 are both located at the top of the separation box 9, and the horizontal heights of the input pipe and the output pipe of the separation box 9 are consistent with the horizontal height of the slurry discharge pipe 39 to prevent a pressure difference between the separation box 9 and the slag box 7. The centrifugal drum type active separator 49 is externally connected to a motor 60.

[0064] like Fig.10 As shown, the remote control system 47 includes a speed regulating propulsion module and a pressure regulating propulsion module, which are respectively connected to the propulsion cylinder 19 and the mud pump 5 in the shield power system 6; the speed regulating propulsion module is used to control the forward speed of the propulsion cylinder 19, thereby controlling the excavation speed of the shield body 10, and the pressure regulating propulsion module is used to control the pumping pressure and flow of the mud in the mud pump 5. The speed regulating propulsion module includes a filter 68, a one-way valve 69 and a servo valve 70. One end of the filter 68 is connected to the first port of the swivel joint 67, and the other end of the filter 68 is connected to the first port of the swivel joint 67. The directional valve 69 and the servo valve 70 are connected to one end of the propulsion cylinder 19, and the other end of the propulsion cylinder 19 is connected to the second port of the rotary joint 67; the pressure regulating propulsion module includes an electromagnetic ball valve 71, a pressure reducing valve 72, a reversing valve 73, a proportional speed regulating valve 74 and a gear flowmeter 75, one end of the electromagnetic ball valve 71 is connected to the third port of the rotary joint 67, the other end of the electromagnetic ball valve 71 is connected to one end of the mud pump 5 through the pressure reducing valve 72, the reversing valve 73, the proportional speed regulating valve 74 and the gear flowmeter 75 in sequence, the other end of the mud pump 5 is connected to the fourth port of the rotary joint 67, and the rotary joint 67 is externally connected to a power supply.

[0065] Specifically, the rotary joint 67 is mainly composed of four power supplies in parallel, and the filter 68, the thrust cylinder 19, the electromagnetic ball valve 71 and the mud pump 5 are respectively connected to one end of the four power supplies, and the other end of the power supply connected to the filter 68 / electromagnetic ball valve 71 is connected to a large power supply through a switch valve.

[0066] All components in the pressure regulating propulsion module and the speed regulating propulsion module, as well as the rotary joint 67, are controlled by a remote computer. In the speed regulating propulsion module, a filter 68 is set after the rotary joint 67 to filter the debris that may be generated by the operation of the rotary joint 67 and protect the servo valve 70 from being contaminated. At the same time, a one-way valve 69 is set to prevent the return oil impact from damaging the filter. The hydraulic cylinder has a built-in displacement sensor, and the piston rod is equipped with a force sensor. The controller controls the signal of the servo valve 70 to achieve closed-loop control of the propulsion speed and output force of the oil cylinder 19; the hydraulic oil side of the mud pump 5 is controlled by a proportional speed regulating valve 74, and the reversing valve 73 can switch different proportional speed regulating valves to adjust different hydraulic input flows. The flow data is recorded by a gear flowmeter 75. Since the rated working pressure of the mud pump 5 is different from that of the hydraulic cylinder, a deceleration valve 72 needs to be set to protect the mud pump 5, and an electromagnetic ball valve 71 is set for emergency shutdown.

[0067] like Figure 8 As shown, the slurry discharge pipe 39 includes a spiral core shaft 52, a spiral blade 58, an outer tube 53, a discharge inlet 54, a discharge outlet 55 and a reducer 51; the spiral blade 58 is in a concentric annular spiral shape, and the spiral blade 58 is coaxially fixedly connected to the outer side wall of the spiral core shaft 52 and connected to form an integral structure of the shaftless spiral 16, the shaftless spiral 16 is arranged inside the outer tube 53, and the two ends of the outer tube 53 are respectively provided with a discharge inlet 54 and a discharge outlet 55, the discharge inlet 54 and the discharge outlet 55 of the outer tube 53 are respectively connected to the mud and water tank 13 and the separation box 9, and the end of the shaftless spiral 16 close to the discharge outlet 55 is connected to the output shaft of the spiral drive motor 8, and a reducer 51 is installed between the side of the shaftless spiral 16 close to the discharge outlet 55 and the spiral drive motor 8.

[0068] An observation window 56 is provided on the outer tube 53 for observing the discharge of mud in the discharge pipe 39. If the required length of the discharge pipe 39 is too long, multiple discharge pipes 39 can be connected through a connecting flange 57 to form a discharge pipe 39 of sufficient length.

[0069] The switching valve group 23 is mainly composed of two branch pipes, a slag inlet pipe and a slag outlet pipe. One end of the slag inlet pipe is connected to the separation box 9, and the other end of the slag inlet pipe is respectively connected to the input ends of the two branch pipes. The output ends of the two branch pipes are connected to one end of the slag outlet pipe, and the other end of the slag outlet pipe is connected to the slag box 7. An electromagnetic valve six 35 and a damping one 37 are provided on one branch pipe, and an electromagnetic valve seven 36 and a damping two 38 are provided on the other branch pipe. An electromagnetic flowmeter 22 is provided on the slag outlet pipe.

[0070] Solenoid valve 1 26, solenoid valve 2 30, solenoid valve 3 31, solenoid valve 4 32, solenoid valve 5 34, solenoid valve 6 35, solenoid valve 7 36, damper 1 37 and damper 2 38 are all connected to a remote control system 47, which is used to control the opening and closing states of all solenoid valves and dampers.

[0071] The embodiment of the present invention is as follows, comprising the following steps:

[0072] Preparation stage:

[0073] S1: Power on and self-check each component in the device without starting any moving components, check the initial state of each sensor and the video signal in the mud and water tank 13; then perform a no-load operation check on the device: use the variable frequency motor 4 to slowly rotate the cutter head 12, extend and push the power box 11 about 10 mm, and then the external electronic control system rotates the shaftless screw 16 in the slurry discharge pipe 39 to check whether the movement state of the above-mentioned moving components and the numerical display of each parameter of the electronic control system console are abnormal, mainly including the gas pressure and mud level monitoring equipment in the air cushion cabin 15, the mud pressure and mud level monitoring equipment in the mud and water tank 13, and the electromagnetic flowmeter 22 of the slurry inlet and discharge system. If an abnormality occurs, suspend the test, overhaul it in time, and restart the test after the overhaul is completed;

[0074] S2: Then, according to the actual shield parameters required for simulation in the test, such as the excavation speed, the rotation speed of the cutterhead, and the foundation soil and water pressure, the target g value required to be achieved by the device, the lateral pressure of the foundation soil and water, the excavation speed, the rotation speed of the cutterhead, the air pressure of the air cushion cabin 15, the mud pressure of the mud and water cabin 13, and the excavation distance are determined; according to the ratio of the slag volume cut into the mud and water cabin 13 to the slurry volume per unit time of 1:11.7, the slurry flow rate during the excavation process of the device is determined in combination with the excavation speed and the excavation distance; according to the slurry flow rate and the slag flow rate, the slurry discharge flow rate during the excavation process of the device is determined; according to the slurry pressure of the mud and water cabin 13 and the slurry discharge flow rate during the excavation process of the device, the damping 1 37 and the damping 2 38 are set;

[0075] Trial phase:

[0076] Step 1: Under normal gravity conditions, the soil box 1 is removed from the base 2, and the hole on the side wall of the soil box 1 is sealed with an aluminum plate 59, and then a soil sample is prepared in layers in the soil box 1 and a sensor is buried in the soil sample. A wire brush is used to perform a 2 mm polishing treatment on the top of the foundation soil. The sensors buried in the soil sample include a bending element sensor, a micro soil pressure gauge, a micro pore pressure sensor, a TDR sensor, a fiber Bragg grating displacement sensor, an air pressure sensor, etc.;

[0077] Step 2: The soil sample in the soil box 1 is saturated by using a saturation box in a vacuum manner. When the soil sample is saturated, the soil box 1 is hoisted onto the base 2 as a whole by a crane and fixed, and the installed shield tunneling module is hoisted into the second hanging basket 46 of the geotechnical centrifuge 42 and fixed, and the sensor, torque sensor 18, propulsion cylinder 19 and mud pump 5 in the soil sample are all connected to the remote control system 47;

[0078] Step 3: Prepare mud according to a preset ratio of bentonite and water, and then inject the mud into the mud and water tank 3, push the shield 10 and the cutter head 12 into the hole of the soil box 1, close the slurry discharge pipe 39, and continuously inject the mud into the working cabin through the mud pump 5, the slurry inlet pipe 1 28 and the slurry inlet pipe 2 29. When the mud and water tank 13 is full of mud and the liquid level in the air cushion cabin 15 reaches 2 / 3 of the cabin shell diameter, proceed to step 4; specifically, the ratio of water, bentonite and CMC in the test scheme is 1000:600:1.

[0079] Step 4: Continue to inject mud. When mud seeps out of the overflow pipe 25, close the solenoid valve 26, and then open the pressure-maintaining system 24 to adjust the air pressure in the air cushion cabin 15, so that the overall mud pressure is slightly higher than the lateral water and soil pressure of the soil sample (i.e., the lateral soil and water pressure outside the cutter head), and then remove the aluminum plate 59 sealed at the hole of the soil box 1, so that the pressurized mud penetrates into the soil sample and forms a mud film in the front soil layer;

[0080] Step 5: Start the geotechnical centrifuge 42, control the shield 10 to cut forward, and obtain the soil response law during the shield excavation process according to the sensor in the soil box 1;

[0081] Step 6: When the shield body 10 reaches the preset excavation distance, stop excavation, close the slurry inlet and outlet pipelines, and control the air pressure in the air cushion cabin 15 to gradually decrease or increase, so as to realize active or passive destruction of the shield excavation surface. At the same time, according to the changes in soil and water pressure in the soil body in front and the mud pressure in the mud water cabin 13, determine the limit support pressure, and then obtain the stability law of the mud balance shield excavation surface.

[0082] Specifically, step 5 is as follows:

[0083] Step 5.1: Start the geotechnical centrifuge 42. During the process of increasing the centrifugal acceleration Ng, the lateral pressure of the soil and water outside the cutter disc 12 will gradually increase with the increase of the centrifugal acceleration Ng value. Close the solenoid valve 2 30 and the solenoid valve 3 31 on the slurry inlet pipes 28 and 29 and the solenoid valve 5 34 of the slurry discharge pipeline, and control the pressure-maintaining system 24 to inlet air into the air cushion cabin 15, so that the mud fills the mud and water tank 13, and the mud pressure in the mud and water tank 13 is equal to the lateral pressure of the soil and water outside the cutter disc 12; keep the cutter disc 13 idling, so that the stirring rod on the back of the cutter disc 13 forms a stirring effect on the mud, and prevents the mud in the mud and water tank 13 from segregating during the process of increasing g; turn on the mud pump 5 and the solenoid valve 4 32, so that the mud circulates in the bypass pipe 33 to prevent segregation and precipitation, and at the same time turn on the stirring motor 76 in the mud and water tank 3, so that the stirring rod 65 stirs the mud to prevent the mud from segregating;

[0084] Step 5.2: When the centrifugal acceleration of the geotechnical centrifuge 42 reaches the preset Ng and lasts for the preset time, the solenoid valve 4 32 is closed, the pressure-maintaining system 24 controls the air pressure in the air cushion cabin 15 to remain unchanged, and the solenoid valve 2 30 of the slurry inlet pipeline and the solenoid valve 5 34 of the slurry discharge pipeline are opened; at the same time, the solenoid valve 6 35 or the solenoid valve 7 36 is opened according to the preset damping start switching valve group 23, and the mud and slag will be driven by the pressure difference between the mud and water cabin 13 and the slag box 7, and transported to the separation box 9 through the spiral blade 58 in the slurry discharge pipe 39, and then the slag particles are separated and filtered by the separation box 9, and then enter the slag box 7;

[0085] Step 5.3: According to the preset excavation speed, cutter head speed and slurry flow rate, the screw drive motor, propulsion cylinder 19 and mud pump 5 are regulated by the remote control system 47, so that the shield body 10 cuts forward and propels forward, and the soil response law during the shield excavation process is obtained according to the sensors set in the soil box 1.

[0086] Personnel in the technical field can easily make various changes and modifications based on the text description, drawings and claims provided by the present invention without departing from the concept and scope of the present invention defined by the claims. Any modification or equivalent change made to the above embodiments based on the technical concept and essence of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A slurry shield tunneling method suitable for super gravity simulation, characterized in that: The method adopts a slurry balance shield tunneling device suitable for supergravity simulation, the device comprising a shield tunneling module, a geotechnical centrifuge (42) and a remote control system (47); the shield tunneling module is placed on the geotechnical centrifuge (42), the shield tunneling module is connected to the remote control system (47), the shield tunneling module comprises a soil box (1), a shield body (10), a shield power system (6) and a slurry inlet and outlet system, the soil box (1) and the shield power system are connected through the shield body (10), the shield body (10) is also connected to the slurry inlet and outlet system, the soil box (1), the shield power system and the slurry inlet and outlet system are all fixedly connected to a base (2), and the base (2) is placed on the hanging basket of the geotechnical centrifuge (42); The geotechnical centrifuge (42) comprises a first hanging basket (43), a second hanging basket (46) and a centrifuge base; the first hanging basket (43) and the second hanging basket (46) are respectively fixedly mounted on both sides of the centrifuge base via rotating arms (45); The shield body (10) comprises a hull with a working cabin inside, a cutter head (12), an annular front baffle (14) and a main shaft (17); the front baffle (14) is located inside the hull and divides the working cabin into a mud and water cabin (13) and an air cushion cabin (15); the cutter head (12) is located on a side close to the mud and water cabin (13); one end of the main shaft (17) is connected to the shield power system; the other end of the main shaft (17) passes through the air cushion cabin (15), the front baffle (14) and the mud and water cabin (13) in sequence and is coaxially connected to the cutter head (12); a hull is provided with a working cabin; ... One end of a mud and water chamber (13) is movably connected to the opening of a soil box (1) so as to be movable forward and backward; one end of an air cushion chamber (15) is fixedly connected to a shield power system in a shell; the shield power system is used to drive the cutter head (12) to rotate and drive the main shaft (17) to dig forward along its own axial direction; the mud and water chamber (13) and the cutter head (12) are both arranged at the opening of the soil box (1); a pressure maintaining system (24) is arranged inside the shell, and the pressure maintaining system (24) is used to control and adjust the gas pressure in the air cushion chamber (15); The shield power system (6) comprises a variable frequency motor (4), a torque sensor (18), a power box (11), a propulsion cylinder (19) and a ball guide rail (48); the ball guide rail (48) is fixed on the upper surface of the base (2); the propulsion cylinder (19) can be reciprocated along the extension direction of the ball guide rail (48); the power box (11) is fixedly mounted on the propulsion cylinder (19); the variable frequency motor (4) and the torque sensor (18) are both arranged inside the power box (11); The side wall of the box (11) is fixedly connected to one end of the cabin shell; an opening is provided on the side wall of the power box (11) on the side close to the shield body (10) as a power box outlet; one end of the main shaft (17) passes through the power box outlet and is connected to the output shaft of the variable frequency motor (4); a torque sensor (18) is provided on the outer surface of the main shaft (17) on the side close to the variable frequency motor (4); the torque sensor (18) is connected to the remote control system (47); the torque sensor (18) transmits the collected torque signal to the remote control system (47); The slurry inlet and discharge system comprises a slurry pump (5), a slurry water tank (3), a slurry inlet pipe 1 (28), a slurry inlet pipe 2 (29), an overflow pipe (25), a bypass pipe (33), a screw drive motor (8), a slurry discharge pipe (39), a separation box (9) and a slag box (7); the slurry pump (5), the slurry water tank (3), the separation box (9) and the slag box (7) are all placed on a base (2), the slurry pump (5) and the output end of the slurry water tank (3) are connected, the slurry pump (5) is connected to the slurry water tank (13) through the slurry inlet pipe 1 (28), the slurry pump (5) is connected to the air cushion cabin (15) through the slurry inlet pipe 2 (29), the slurry inlet pipe 1 ( A solenoid valve 2 (30) and a solenoid valve 3 (31) are respectively arranged on the first mud pump (5) and the second mud inlet pipe (28) and the second mud inlet pipe (29); an overflow pipe (25) is arranged at a position 4 / 5 of the height of the mud water tank (13); both ends of the overflow pipe (25) are respectively connected to the mud water tank (13) and the atmosphere; a solenoid valve 1 (26) is arranged on the overflow pipe (25); a bypass pipe (33) is also arranged between the mud pump (5) and the mud water tank (3); one end of the bypass pipe (33) is connected to the mud water tank (3); and the other end is respectively connected to the mud pump (5), the first mud inlet pipe (28) and the second mud inlet pipe (29); and a solenoid valve 4 (32) is arranged on the bypass pipe (33); A slurry discharge pipe opening is provided at the bottom of the front partition (14), one end of the slurry discharge pipe (39) passes through the slurry discharge pipe opening and is communicated with the mud and water tank (13), the other end of the slurry discharge pipe (39) is communicated with one end of the separation box (9) through a pipeline, a solenoid valve (34) is provided on the pipeline from the slurry discharge pipe (39) to the separation box (9), the other end of the separation box (9) is connected to the slag box (7) through a switching valve group (23), and the other end of the slurry discharge pipe (39) is also connected to the output shaft of the screw drive motor (8), and the screw drive motor (8) is used to drive the slurry discharge pipe (39) to rotate; The remote control system (47) comprises a speed regulating propulsion module and a pressure regulating propulsion module, wherein the speed regulating propulsion module and the pressure regulating propulsion module are respectively connected to the propulsion cylinder (19) and the mud pump (5) in the shield power system (6); the speed regulating propulsion module is used to control the forward speed of the propulsion cylinder (19), thereby controlling the excavation speed of the shield body (10); the pressure regulating propulsion module is used to control the pumping pressure and flow rate of the mud in the mud pump (5); the speed regulating propulsion module comprises a filter (68), a one-way valve (69) and a servo valve (70); one end of the filter (68) is connected to the first port of the swivel joint (67), and the other end of the filter (68) is connected to the first port of the swivel joint (67), and the other end of the filter (68) is connected to the first port of the swivel joint (67) through the one-way valve (69) and the servo valve (70) in sequence. The service valve (70) is connected to one end of the propulsion cylinder (19), and the other end of the propulsion cylinder (19) is connected to the second port of the rotary joint (67); the pressure regulating propulsion module comprises an electromagnetic ball valve (71), a pressure reducing valve (72), a reversing valve (73), a proportional speed regulating valve (74) and a gear flow meter (75); one end of the electromagnetic ball valve (71) is connected to the third port of the rotary joint (67), and the other end of the electromagnetic ball valve (71) is connected to one end of the mud pump (5) through the pressure reducing valve (72), the reversing valve (73), the proportional speed regulating valve (74) and the gear flow meter (75) in sequence; the other end of the mud pump (5) is connected to the fourth port of the rotary joint (67), and the rotary joint (67) is externally connected to a power supply; The slurry discharge pipe (39) comprises a spiral mandrel (52), a spiral blade (58), an outer tube (53), a discharge inlet (54), a discharge outlet (55) and a reducer (51); the spiral blade (58) is in a concentric annular spiral shape, the spiral blade (58) is coaxially connected to the outer side wall of the spiral mandrel (52) and connected to form an integral shaftless spiral (16); the shaftless spiral (16) is arranged inside the outer tube (53); the two ends of the outer tube (53) are respectively provided with a discharge inlet (54) and a discharge outlet (55); the discharge inlet (54) and the discharge outlet (55) of the outer tube (53) are respectively connected to the mud and water tank (13) and the separation box (9); one end of the shaftless spiral (16) close to the discharge outlet (55) is connected to the output shaft of the spiral drive motor (8); and a reducer (51) is installed between one side of the shaftless spiral (16) close to the discharge outlet (55) and the spiral drive motor (8); A stirring motor (76) and a stirring rod (65) are provided inside the mud and water tank (3), and the stirring rod (65) is connected to the stirring motor (76); The method comprises the following steps: Step 1: Under normal gravity conditions, the soil box (1) is removed from the base (2), and the opening of the side wall of the soil box (1) is sealed with an aluminum plate (59), and then soil samples are prepared in layers in the soil box (1) and sensors are buried in the soil samples; the sensors buried in the soil samples include bending element sensors, micro soil pressure gauges, micro pore pressure sensors, TDR sensors, fiber Bragg grating displacement sensors, and air pressure sensors; Step 2: Using a saturation box, saturate the soil sample in the soil box (1). When the soil sample is saturated, the soil box (1) is hoisted as a whole onto the base (2) by a crane and fixed. The installed shield tunneling module is hoisted into the second hanging basket (46) of the geotechnical centrifuge (42) and fixed. The sensor, torque sensor (18), propulsion cylinder (19) and mud pump (5) in the soil sample are connected to the remote control system (47). Step 3: Prepare mud according to a preset ratio of bentonite and water, then inject the mud into the mud water tank (3), push the shield (10) and the cutter head (12) into the hole of the soil box (1), close the mud discharge pipe (39), and continuously inject the mud into the working cabin through the mud pump (5). When the mud water tank (13) is full of mud and the liquid level in the air cushion cabin (15) reaches 2 / 3 of the cabin shell diameter, proceed to step 4; Step 4: Continue to inject mud. When mud seeps out of the overflow pipe (25), close the electromagnetic valve 1 (26), and then open the pressure-maintaining system (24) to adjust the air pressure in the air cushion cabin (15) so that the overall mud pressure is higher than the lateral water and soil pressure of the soil sample. Then remove the aluminum plate (59) sealing the hole of the soil box (1) to allow the pressurized mud to seep into the soil sample and form a mud film in the soil layer in front. Step 5: Start the geotechnical centrifuge (42), control the shield (10) to cut forward, and obtain the soil response law during the shield excavation process according to the sensor in the soil box (1); Step 6: When the shield body (10) reaches a preset excavation distance, excavation is stopped, the slurry inlet and outlet pipelines are closed, and the air pressure in the air cushion cabin (15) is controlled to gradually decrease or increase, so as to achieve active or passive destruction of the shield excavation surface. At the same time, according to the changes in the soil and water pressure of the soil body in front and the changes in the mud pressure in the mud water cabin (13), the limit support pressure is determined, and then the stability law of the mud water balance shield excavation surface is obtained.

2. A slurry shield tunneling method suitable for super gravity simulation according to claim 1, characterized in that: The specific steps of step 5 are as follows: Step 5.1: Start the geotechnical centrifuge (42). When the centrifugal acceleration Ng increases, close the electromagnetic valve 2 (30) on the slurry inlet pipe 1 (28), the electromagnetic valve 3 (31) on the slurry inlet pipe 2 (29), and the electromagnetic valve 5 (34) of the slurry discharge pipeline, and control the pressure-maintaining system (24) to feed air into the air cushion cabin (15), so that the mud fills the mud and water tank (13), and the mud pressure in the mud and water tank (13) is equal to the lateral pressure of the soil and water outside the cutterhead (12); turn on the mud pump (5) and the electromagnetic valve 4 (32), so that the mud circulates in the bypass pipe (33) to prevent segregation and precipitation, and at the same time turn on the stirring motor (76) in the mud and water tank (3), so that the stirring rod (65) stirs the mud to prevent the mud from segregating; Step 5.2: When the centrifugal acceleration of the geotechnical centrifuge (42) reaches a preset value Ng and lasts for a preset time, the electromagnetic valve four (32) is closed, the pressure-maintaining system (24) controls the air pressure in the air cushion cabin (15) to remain unchanged, and the electromagnetic valve two (30) of the slurry inlet pipeline and the electromagnetic valve five (34) of the slurry discharge pipeline are opened; at the same time, the switching valve group (23) is started according to the preset damping, and the mud and slag are driven by the pressure difference between the mud and water cabin (13) and the slag box (7) and transported to the separation box (9) through the spiral blades (58) in the slurry discharge pipe (39), and then the slag particles are separated and filtered by the separation box (9) and then enter the slag box (7); Step 5.3: According to the preset excavation speed, cutter head rotation speed and slurry flow rate, the remote control system (47) is used to control the propulsion cylinder (19) and the slurry pump (5), so that the shield (10) cuts forward and propels forward, and the soil response law during the shield excavation process is obtained based on the sensors installed in the soil box (1).

3. The slurry shield tunneling method suitable for super gravity simulation according to claim 1, characterized in that: The pressure maintaining system (24) comprises an air intake pipe (20), an exhaust pipe (21), a pressure transmitter (64), an air intake regulating valve (62), an exhaust regulating valve (63) and an electronic control system (61); an air intake port and an air outlet are provided at the end of the cabin shell close to the shield power slag box system; one end of the air intake pipe (20) passes through the air intake port and is connected to the air cushion cabin (15); the other end of the air intake pipe (20) is connected to an external air source; one end of the exhaust pipe (21) passes through the exhaust port and is connected to the air cushion cabin (15); the other end of the exhaust pipe (21) is connected to the external atmosphere; the air intake pipe (20) and the exhaust pipe (21) are respectively provided with air intake regulating valves. A pressure transmitter (64) is installed in the air cushion cabin (15). The pressure transmitter (64) is used to measure the gas pressure in the air cushion cabin (15). The pressure transmitter (64), the air intake regulating valve (62) and the exhaust regulating valve (63) are all connected to the electronic control system (61). The pressure transmitter (64) transmits the real-time collected gas pressure signal to the electronic control system (61). The electronic control system (61) controls the air intake regulating valve (62) and the exhaust regulating valve (63) by comparing the preset air pressure value with the collected actual air pressure value, so that the gas pressure in the air cushion cabin (15) is maintained at the preset air pressure value.

4. The slurry shield tunneling method suitable for super gravity simulation according to claim 1, characterized in that: The separation box (9) is provided with a centrifugal drum type active separator (49) and a vertical filter (50) inside. The slurry output from the slurry discharge pipe (39) flows into the input end of the centrifugal drum type active separator (49), is filtered by the centrifugal drum type active separator (49) and the vertical filter (50) in turn, and then flows out of the separation box (9). The aperture size of the flow channel of the centrifugal drum type active separator (49) and the aperture size of the mesh of the vertical filter (50) are both smaller than the maximum particle size that can pass through the switching valve group (23). The input pipe and the output pipe connected to the separation box (9) are both located at the top of the separation box (9), and the horizontal heights of the input pipe and the output pipe of the separation box (9) are consistent with the horizontal height of the slurry discharge pipe (39). The centrifugal drum type active separator (49) is externally connected to a motor (60).

5. The slurry shield tunneling method suitable for super gravity simulation according to claim 1, characterized in that: The switching valve group (23) is mainly composed of two branch pipes, a slag inlet pipe and a slag outlet pipe. One end of the slag inlet pipe is connected to the separation box (9), and the other end of the slag inlet pipe is respectively connected to the input ends of the two branch pipes. The output ends of the two branch pipes are connected to one end of the slag outlet pipe, and the other end of the slag outlet pipe is connected to the slag box (7). One branch pipe is provided with an electromagnetic valve six (35) and a damping one (37), and the other branch pipe is provided with an electromagnetic valve seven (36) and a damping two (38). The slag outlet pipe is provided with an electromagnetic flowmeter (22).

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