Attitude-adjustable shield tunneling simulation device and method for sandy soil stratum

Abstract

The invention discloses a posture-adjustable shield tunneling simulation device for a sandy soil stratum. The posture-adjustable shield tunneling simulation device comprises a soil box, a shield tunneling machine model, a pedestal and a monitoring system, the shield tunneling machine model comprises a shield body, a cutterhead, a transmission system, a propelling system and a dumping system. The soil box is filled with a test soil body; the shield body is slidably installed on a sliding rail on the top of the pedestal and faces the opening side of the soil box. The cutterhead is rotationally arranged at the front end of the shield body, and the aperture ratio is adjustable. A transmission shaft in the transmission system is driven by the first driving piece to drive the cutter head to rotate. The propelling system is arranged at the rear end of the shield body and comprises a power module and a posture adjusting module. The power module drives the shield body to axially advance; in the posture adjusting module, a hydraulic control unit controls a plurality of sets of posture adjusting oil cylinders abutting against the rear end of the shield body to generate differentiated expansion and contraction amounts so as to adjust the tunneling angle. The soil discharging system is used for discharging muck in the shield body, and the monitoring system is used for monitoring test data during tunneling simulation. The invention further discloses a shield tunneling simulation method based on the simulation device.

Description

Technical Field

[0001] The present invention relates to the technical field of shield machine excavation simulation equipment, and in particular to a posture-adjustable shield excavation simulation device and method for sandy soil strata. Background Art

[0002] Shield tunneling has become a core method for urban rail transit tunnel construction due to its advantages such as high safety, strong adaptability, and low construction disturbance. The marine sand layers formed by land reclamation are widely used in my country's coastal areas. Their high compressibility, low bearing capacity, and susceptibility to disturbance pose severe challenges to shield construction. Engineering practice has shown that the difficulty of controlling the excavation posture in such strata increases significantly, which can easily lead to engineering hazards such as trajectory deviation axis, segment damage, and water leakage, directly affecting construction safety and forming quality. Using indoor model tests to study such issues has significant efficiency advantages, but existing shield model test platforms generally suffer from insufficient stratum adaptability, making it difficult to accurately simulate the excavation characteristics of sandy strata such as marine sand reclamation.

[0003] As the core equipment for experimental research, shield model machines must possess the core functions of actual shield machines, such as excavation, slag discharge, and attitude control. Current mainstream model machines generally have simplified functions: most devices can only perform basic excavation actions and lack real-time attitude control capabilities; the cutterhead system mostly adopts a static design, which deviates from the dynamic cutting mechanism in actual excavation; the soil discharge system structure is too simplified, making it difficult to restore the actual soil transportation conditions. Existing research equipment is mostly customized for a single stratum, mainly for conventional soft soil or clay layer excavation research. When it comes to complex working conditions such as the blown sand formations on the southeast coast, its functional adaptability and stratum restoration are obviously insufficient. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide an adjustable hardware foundation and method for simulating shield tunneling construction, so as to accurately simulate the tunneling construction process of a shield machine in sandy soil strata such as blown sand strata.

[0005] In order to solve the above technical problems, the present invention provides an adjustable shield tunneling simulation device for sandy soil, comprising a soil box, a shield machine model, a pedestal and a monitoring system; wherein the shield machine model comprises a shield body, a cutterhead, a transmission system, a propulsion system and a soil discharge system;

[0006] The soil box is filled with test soil; a horizontally extending slide rail is provided on the pedestal, and the shield body is slidably mounted on the slide rail and is provided with an opening on one side facing the soil box; a soil compartment is constructed in the shield body through a plurality of partitions;

[0007] The cutter disc is rotatably arranged at one end of the shield body near the soil box; the transmission system includes a first driving member and a transmission shaft coaxially arranged with the shield body; one end of the transmission shaft is connected to the first driving member, and the other end is connected to the cutter disc, so as to drive the cutter disc to rotate under the drive of the first driving member;

[0008] The propulsion system is arranged at the end of the shield body away from the soil box, and includes a power module and a posture adjustment module; the power module is used to drive the shield body to propel axially; the posture adjustment module includes a hydraulic control unit and a posture adjustment cylinder; a plurality of groups of the posture adjustment cylinders are pressed against the end of the shield body away from the soil box at multiple points; the hydraulic control unit is connected to the posture adjustment cylinders to control each group of the posture adjustment cylinders to produce an independent extension and contraction amount;

[0009] The soil discharge system is connected to the soil compartment in the shield body and is used to discharge the soil during the excavation process of the shield body;

[0010] The monitoring system is used to monitor the test data of the shield machine model during simulated excavation, and the test data includes one or more groups of the propulsion speed, propulsion posture, cutter head rotation speed or water and soil pressure at the interface between the shield body and the test soil of the shield machine model.

[0011] In a preferred embodiment, the cutter disc adopts a spoke plate structure; the cutter disc is provided with a spoke plate at the center for adjusting the opening ratio of the cutter disc.

[0012] In a preferred embodiment, the cutter disc adopts a central support structure, including a plurality of radially arranged spokes, a centrally arranged center knife, and a plurality of groups of cutting knives and rolling knives spaced apart in the extending direction of the spokes.

[0013] In a preferred embodiment, a plurality of groups of the posture adjustment cylinders are arranged at intervals along the circumferential direction on the end surface of the shield body.

[0014] In a preferred embodiment, the test soil is mixed in the following proportions: a mass ratio of barite powder to standard sand of 0.15, a binder concentration of 0.5%, a powder-to-silicon ratio of 3:1, a gypsum content of 6%, and a bentonite content of 6.5%.

[0015] In a preferred embodiment, the power module includes a second driving member, a reducer, a coupling and a thrust rod connected in sequence toward the soil box; the thrust rod is used to control the excavation and retreat of the cutterhead.

[0016] In a preferred embodiment, a shield tail sealing mechanism is provided on the side of the propulsion system and the end of the shield body away from the soil box.

[0017] In a preferred embodiment, the monitoring system includes one or more of an excavation position deviation sensor, a cutterhead speed sensor, a shield machine model propulsion speed sensor, a jack propulsion stroke sensor, a jack propulsion pressure sensor, a shield body soil pressure sensor and a soil pore water pressure gauge.

[0018] In a preferred embodiment, the soil discharge system includes a slurry pipe, and a mud bucket, a mud pump, an accumulator, an electric ball valve, an electromagnetic flowmeter, a slurry inlet baffle, a rotating baffle, a mud discharge pipe, a spring flexible shaft and a slurry collection bucket connected in sequence through the slurry pipe.

[0019] The present invention also provides a method for simulating shield tunneling with adjustable posture in sandy soil, using the simulation device described above. The simulation method comprises the following steps:

[0020] Step 1: Adjust the debugged shield machine model to zero position;

[0021] Step 2: Prepare the test soil;

[0022] Step 3: Install the displacement sensor;

[0023] Step 4: Debug the monitoring system, set up the video acquisition equipment, and set up the collected data.

[0024] Step 5: Turn on the simulation device and set the test parameters;

[0025] Step 6: Carry out the test according to the design plan;

[0026] Step 7: Collect and analyze experimental data.

[0027] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0028] The posture adjustment module provided in the simulation device provided by the present invention realizes dynamic adjustment of the propulsion angle by differentially adjusting the extension and contraction of the oil cylinder, effectively dealing with the horizontal and vertical deviations and yaw angle fluctuations caused by uneven soil pressure, and simulating the posture correction process in actual excavation. In addition, the cutterhead adopts an optimized knife group configuration and an adjustable opening ratio design, which takes into account both soft soil cutting efficiency and anti-clogging ability. The soil discharge system realizes continuous transportation of slag through a multi-stage pipeline and mud mixing design, and is fully functional. The monitoring system integrates a variety of sensors to realize real-time and three-dimensional collection of multiple groups of test data such as propulsion speed, cutterhead speed, and water and soil pressure. The test soil is optimized according to the stratum characteristics of the specific engineering situation to ensure that the mechanical properties of the simulated soil are consistent with the actual working conditions. In summary, the simulation device has significantly improved the simulation accuracy of excavation construction in various strata, especially in sandy strata that are prone to deviation, through multi-dimensional technological innovation, providing a scientific and reliable hardware foundation for related experimental research. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a three-dimensional schematic diagram of the simulation device described in Example 1 of the present invention;

[0030] Figure 2 is a schematic cross-sectional view of the simulation device described in Example 1 of the present invention;

[0031] Figure 3 Schematic diagram of the cutter head in Example 1 of the present invention;

[0032] Figure 4 This is a cross-sectional schematic diagram of the attitude adjustment cylinder and the shield tail sealing mechanism described in Example 1 of the present invention;

[0033] Figure 5 This is a connection diagram of the soil discharge system described in Example 1 of the present invention;

[0034] Figure 6 Schematic diagram of the arrangement of the monitoring system described in Example 1 of the present invention (the left side of the figure is a side view, and the right side of the figure is a cross-sectional schematic diagram);

[0035] Figure 7 A diagram showing changes in horizontal and vertical deviations of the shield machine model during simulated tunneling in an embodiment of the present invention;

[0036] Figure 8 This is a diagram showing the change in yaw angle of the shield machine model during the simulated tunneling process in an embodiment of the present invention.

[0037] The following are marked in the figure: 1-soil box, 2-shield machine model, 3-cutterhead, 4-propulsion system, 5-soil discharge system, 6-stainless steel box frame, 7-high-definition tempered glass, 8-spoke plate, 9-center knife, 10-cutter, 11-hob, 12-ring, 13-spoke, 14-attitude adjustment cylinder, 15-guide column, 16-reaction frame, 17-drive shaft, 18-first drive member, 19-pedestal, 20-thrust rod, 21-coupling, 22-reducer, 23-second drive member, 24-mud bucket, 25-mud agitator, 26-transmission Slurry pipe, 27-mud pump, 28-accumulator, 29-electric ball valve, 30-electromagnetic flowmeter, 31-slurry inlet baffle, 32-rotating baffle, 33-mud outlet pipe, 34-spring flexible shaft, 35-slurry collection bucket, 36-excavation position deviation sensor, 37-cutterhead speed sensor, 38-shield machine model propulsion speed sensor, 39-jack propulsion stroke sensor, 40-jack propulsion pressure sensor, 41-shield body soil pressure sensor, 42-pore water pressure gauge, 43-seal, 44-sealing lubricating oil, 45-ball bowl. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0041] Example 1

[0042] like Figures 1 to 8 As shown, an embodiment of the present invention provides an adjustable shield tunneling simulation device for sandy soil strata, including a soil box 1, a shield machine model 2, a pedestal 19 and a monitoring system.

[0043] like Figure 1 As shown, the soil box 1 includes a stainless steel box frame 6 and high-definition tempered glass 7. The soil box 1 is also constructed with a monitoring system wiring hole groove. The external dimensions of the soil box 1 are 6000mm long × 3550mm wide × 3550mm high, and the internal dimensions are 4980mm long × 2100mm wide × 3345mm high. The soil box 1 is constructed with observation windows on both sides of the excavation direction, and the dimensions of the observation windows are 1900mm long × 1500mm high. The soil box 1 is filled with test soil. The tunnel excavation working condition simulated in this embodiment is the blown sand formation in the Xiamen sea area, so the optimal ratio of the test soil is: the mass ratio of barite powder to standard sand is 0.15, the binder concentration is 0.5%, the ratio of vanadium to silicon is 3:1, the gypsum content is 6%, and the bentonite content is 6.5%.

[0044] The installation height of the shield machine model 2 relative to the soil box 1 is: the center is 930mm from the ground and 2270mm from the top of the soil box 1. Figure 1 、 Figure 2 As shown, the shield machine model 2 generally comprises a shield body, a cutterhead 3, a transmission system, a propulsion system 4, and a soil discharge system 5. The base 19 is provided with horizontally extending slide rails, on which the shield body is slidably mounted, with one side opening toward the soil box 1. A soil compartment is constructed within the shield body via a number of partitions. The cutterhead 3 is rotatably mounted at the front end of the shield body via a flange. The transmission system comprises a first drive member 18 and a drive shaft 17 coaxially disposed with the shield body. One end of the drive shaft 17 is connected to the first drive member 18, and the other end is connected to the cutterhead 3, driving the cutterhead 3 to rotate under the drive of the first drive member 18. The first drive member 18 utilizes a hydraulic motor. The propulsion system 4 is located at the rear end of the shield body, driving the shield body's axial propulsion and providing the hardware foundation for dynamic adjustment of the excavation posture. It should be understood that the "front end" refers to the end of the shield body closest to the soil box 1, while the "rear end" refers to the end away from the soil box 1. The soil discharge system 5 is communicated with the soil compartment in the shield body and is used to discharge the debris from the shield body during the excavation process.

[0045] The shield body is a cylindrical structure assembled from several shield segments. The outer diameter of the shield body is 590mm-630mm, the wall thickness is 6mm-10mm, and the overall length is 1000mm-1100mm. Its size is reasonably designed to ensure that the construction simulation of the shield machine model 2 is more in line with the actual working conditions. The shield body includes a front shield and a rear shield, wherein the front shield is 350mm-400mm long and the rear shield is 650mm-700mm long. The front shield and the rear shield are detachably connected axially by bolts. Several partitions are arranged at intervals along the axial direction in the shield body to construct an excavation chamber. The thickness of the partition is 10mm-20mm. A grouting hole is provided above the partition, a clearance hole is provided at the center for the transmission shaft 17 to pass through, and a slag conveyor hole is provided at the bottom.

[0046] like Figure 3As shown, the cutter disc 3 adopts a central support structure, including a number of radially arranged spokes 13, a centrally arranged center knife 9, and a number of groups of cutters 10 and rollers 11 spaced apart in the direction of extension of the spokes 13. The cutter disc 3 is also provided with a number of concentric rings 12, which connect the spokes 13 to improve the overall rigidity of the cutter disc 3. Specifically, the length of the center knife 9 is 200mm to 250mm. In the counterclockwise direction, the distance between the inner side of each group of rollers 11 and the center of the cutter disc 3 is 85mm, 93mm, 101mm, and 109mm, respectively, and the spacing between adjacent rollers 11 is 40mm-55mm. The arrangement of the cutters 10 adopts the single Fermat spiral knife arrangement method, and the two groups of cutters 10 on the same diagonal line are symmetrically arranged. The center-to-center distances of the four cutters 10 on one spoke 13 are 125mm, 195mm, 265mm, and 335mm, respectively, corresponding to cutter 10 widths of 52mm, 38mm, 33mm, and 29mm. The center-to-center distances of the three cutters 10 on the adjacent spoke 13 are 163mm, 220mm, and 265mm, respectively, corresponding to cutter 10 widths of 22.5mm, 20.5mm, and 20mm. The cutterhead 3 utilizes a spoke-plate structure with a convex core-shaped longitudinal cross-section. The cutterhead 3's aperture ratio can be adjusted by removing and installing the spoke plate 8, allowing the appropriate aperture ratio to be adjusted based on different soil layer characteristics before each simulation test. The cutterhead 3's aperture ratio can be adjusted from 10% to 75%.

[0047] like Figure 1 、 Figure 2 As shown, the propulsion system 4 is provided at the tail of the shield machine model 2 (hereinafter referred to as the shield tail), including a power module and a posture adjustment module. The power module is used to drive the shield body to propel axially, including a second drive member 23, a reducer 22, a coupling 21 and a thrust rod 20 connected in sequence in the direction of the soil box 1. The second drive member 23 adopts a hydraulic jack. The power module also includes a guide column 15 for guiding and a reaction frame 16 for providing reverse thrust. During the test, when the thrust rod 20 extends forward, the cutter head 3 advances, and when the thrust rod 20 retracts, the cutter head 3 retreats. The operation is simple and the design is reasonable. The posture adjustment module includes a hydraulic control unit and several groups of parallel attitude adjustment cylinders 14. The hydraulic control unit and the posture adjustment module are externally connected to a wire encoder for detecting the propulsion speed and propulsion stroke. The posture of the shield machine model 2 is detected by a gyroscope. As shown Figure 4As shown, at least four groups of attitude adjustment cylinders 14 are provided, spaced circumferentially around the rear end of the shield body and abutting the end of the shield body away from the soil box 1. The hydraulic control unit is connected to the attitude adjustment cylinders 14, adaptively controlling pressure via a variable displacement pump and controlling thrust pressure and speed via differentiated configurations of proportional relief and pressure-reducing valves. This precisely controls the independent extension and contraction of each group of attitude adjustment cylinders 14. Each group of attitude adjustment cylinders 14 adjusts the thrust angle through differentiated extension and contraction, thereby adjusting the attitude of the shield machine model 2.

[0048] like Figure 4 As shown, the propulsion system 4, located at the rear end of the shield, extends forward through an extension. A shield tail sealing mechanism is located between the extension and the shield body. This shield tail sealing mechanism comprises a seal 43, a sealing lubricant 44, and a ball bowl 45. Two sets of seals 43 are spaced apart between the extension and the shield body. These seals 43 are made from a mixture of nitrile rubber and polyurethane and are cast using a mold. The cavity between each set of seals 43 is used to mount the ball bowl 45, which achieves a sealing effect through the mutual compression between the ball bowl 45 and the seal 43. Furthermore, the gaps between the ball bowl 45 and the shield tail and segments are filled with sealing lubricant 44.

[0049] like Figure 5 As shown, the soil discharge system 5 includes a slurry delivery pipe 26, and a slurry bucket 24, a slurry pump 27, an accumulator 28, an electric ball valve 29, an electromagnetic flowmeter 30, a slurry inlet baffle 31, a rotating baffle 32, a slurry discharge pipe 33, a spring flexible shaft 34 and a slurry collection bucket 35 connected in sequence through the slurry delivery pipe 26. The diameter and height of the slurry bucket 24 are both about 1m, and it is made of plastic material. The maximum capacity for storing slurry is 1.5m 3 To prevent the mud from settling during the test, a homemade mud agitator 25 was used to stir the mud to maintain a uniform state. The agitator consisted of a reducer 22 and a stirring rod, which was equipped with several rotating blades of different heights and fixed by a reaction frame 16.

[0050] like Figure 6As shown, the monitoring system is used to monitor the shield machine model 2 during simulated tunneling, including one or more sets of data related to the shield machine model's propulsion speed, propulsion attitude, cutterhead 3 rotation speed, or the water and soil pressure at the interface between the shield and the test soil. The monitoring system includes one or more of a tunneling position deviation sensor 36, a cutterhead rotation speed sensor 37, a shield machine model propulsion speed sensor 38, a jack propulsion stroke sensor 39, a jack propulsion pressure sensor 40, a shield soil pressure sensor 41, and a soil pore water pressure gauge 42. The monitoring system's layout should be rationally arranged based on its functional characteristics and monitoring requirements. Specifically, in this embodiment, the excavation position deviation sensor 36 is installed at a geometrically critical position of the shield machine model 2 for real-time detection of posture deviation; the cutterhead speed sensor 37 is arranged in a driving area close to the cutterhead 3 to accurately monitor the speed of the cutterhead 3; the shield machine model propulsion speed sensor 38 is provided at the propulsion system 4 to feedback the propulsion status of the shield machine model 2; the jack propulsion stroke sensor 39 and the jack propulsion pressure sensor 40 are respectively arranged at the core part of the jack for recording the propulsion stroke and pressure; the shield body soil pressure sensor 41 and the soil pore water pressure gauge 42 are installed in the contact area between the shield body and the test soil for monitoring soil pressure and pore water pressure.

[0051] The horizontal and vertical deviation change diagrams and yaw angle change diagrams of the shield machine model 2 derived from the monitoring system are shown in the attached diagrams. Figure 7 and 8 The results show that during the tunneling process, the horizontal and vertical attitude deviations and yaw angles of the shield machine model 2 fluctuate due to the influence of uneven earth pressure. The attitude adjustment module then makes real-time adjustments to achieve attitude reset. This demonstrates that the simulation device provided by the embodiment of the present invention can effectively simulate the attitude changes and adjustment processes of the shield machine in actual working conditions, especially in sandy soil strata.

[0052] In summary, the simulation device provided by the present invention features a posture adjustment module that utilizes four circumferentially arranged groups of posture adjustment cylinders 14. A hydraulic control unit precisely adjusts the extension and retraction of each group of cylinders. In conjunction with a wire encoder and gyroscope, posture deviations are monitored in real time. This differential adjustment of the cylinder extension and retraction allows for dynamic adjustment of the propulsion angle, effectively addressing horizontal and vertical deviations and yaw angle fluctuations caused by uneven soil pressure, simulating the posture correction process during actual tunneling. Furthermore, the cutterhead 3 utilizes a segmented arrangement of different-sized cutters 10 and a gradient spacing between the rollers 11, combined with removable spokes 8 to achieve an adjustable opening ratio range of 10%-75%, balancing soft soil cutting efficiency with anti-clogging capabilities. The soil discharge system 5 utilizes a multi-stage pipeline and slurry mixing design for continuous soil transport, providing comprehensive functionality. The monitoring system integrates multiple sensors, enabling real-time, three-dimensional acquisition of multiple test data sets, including propulsion speed, cutterhead 3 rotational speed, and water and soil pressure. The test soil is optimized based on the specific stratum characteristics of the project to ensure that the simulated soil mechanical properties are consistent with actual working conditions. In summary, the simulation device has significantly improved the simulation accuracy of tunneling construction in various strata, especially sandy strata that are prone to displacement, through multi-dimensional technological innovation, providing a scientific and reliable hardware foundation for related experimental research.

[0053] Example 2

[0054] Based on the simulation device described in Example 1, an embodiment of the present invention further provides a method for simulating shield tunneling with adjustable posture in sandy soil, comprising the following steps:

[0055] Step 1, zeroing the shield machine model 2: return the debugged shield machine model 2 to its original position, adjust its posture, and keep the yaw and pitch angles of the shield machine model 2 at zero.

[0056] Step 2: Prepare the test soil: Prepare the binder and add similar model materials in proportion and order to prepare the test soil.

[0057] Step 3, installing the displacement sensor: After the test soil meets the test requirements, a bracket with a laser displacement sensor is fixed on the top of the soil box 1.

[0058] Step 4: Debug each set of sensors in the monitoring system and set up the video acquisition equipment: check the data acquisition device wiring, set the acquisition parameters, and wait for the formal test.

[0059] Step 5: Turn on the simulator and set test parameters: After all preparations are complete, turn on the simulator, enable the tunneling parameter control system and the attitude control system, and check the data storage settings for each monitoring item. Monitor the working status of each component and set the test design parameters.

[0060] Step 6, conduct the test: After all the work is ready, start the test according to the design plan.

[0061] Step 7, collect test data: After the test is completed, collect the collected data in a timely manner and analyze it.

[0062] Step 8, clean up the test site: clean up the site, clean up the soil in the soil box 1, and return the equipment to its original position.

[0063] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any technical equivalent transformation made using the contents of the present invention specification shall fall within the protection scope of the present invention.

Claims

1. A shield tunneling simulation device with adjustable posture for sandy soil, characterized by: It includes a soil box, a shield machine model, a pedestal and a monitoring system; wherein the shield machine model includes a shield body, a cutter head, a transmission system, a propulsion system and a soil discharge system; The soil box is filled with test soil; a horizontally extending slide rail is provided on the pedestal, and the shield body is slidably mounted on the slide rail and is provided with an opening on one side facing the soil box; a soil compartment is constructed in the shield body through a plurality of partitions; The cutter disc is rotatably arranged at one end of the shield body near the soil box; the transmission system includes a first driving member and a transmission shaft coaxially arranged with the shield body; one end of the transmission shaft is connected to the first driving member, and the other end is connected to the cutter disc, so as to drive the cutter disc to rotate under the drive of the first driving member; The propulsion system is arranged at the end of the shield body away from the soil box, and includes a power module and a posture adjustment module; the power module is used to drive the shield body to propel axially; the posture adjustment module includes a hydraulic control unit and a posture adjustment cylinder; a plurality of groups of the posture adjustment cylinders are pressed against the end of the shield body away from the soil box at multiple points; the hydraulic control unit is connected to the posture adjustment cylinders to control each group of the posture adjustment cylinders to produce an independent extension and contraction amount; The soil discharge system is connected to the soil compartment in the shield body and is used to discharge the soil during the excavation process of the shield body; The monitoring system is used to monitor the test data of the shield machine model during simulated excavation, and the test data includes one or more groups of the propulsion speed, propulsion posture, cutter head rotation speed or water and soil pressure at the interface between the shield body and the test soil of the shield machine model.

2. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The cutter disc adopts a spoke plate structure; a spoke plate is provided at the center of the cutter disc for adjusting the opening rate of the cutter disc.

3. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The cutter disc adopts a central support structure, comprising a plurality of radially arranged spokes, a centrally arranged center knife, and a plurality of groups of cutting knives and rolling knives spaced apart in the extending direction of the spokes.

4. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: A plurality of groups of posture adjustment oil cylinders are arranged at intervals along the circumferential direction on the end surface of the shield body.

5. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The test soil has the following proportions: a mass ratio of barite powder to standard sand of 0.15, a binder concentration of 0.5%, a powder-silicon ratio of 3:1, a gypsum content of 6%, and a bentonite content of 6.5%.

6. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The power module includes a second driving member, a reducer, a coupling and a thrust rod which are sequentially connected toward the soil box; the thrust rod is used to control the excavation and retreat of the cutter head.

7. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The propulsion system and the shield body are provided with a shield tail sealing mechanism on the side periphery of one end away from the soil box.

8. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The monitoring system includes one or more of a tunneling position deviation sensor, a cutterhead speed sensor, a shield machine model propulsion speed sensor, a jack propulsion stroke sensor, a jack propulsion pressure sensor, a shield body soil pressure sensor and a soil pore water pressure gauge.

9. The adjustable shield tunneling simulation device for sandy soil according to claim 1, characterized in that: The soil discharge system includes a slurry delivery pipe, and a slurry bucket, a slurry pump, an accumulator, an electric ball valve, an electromagnetic flowmeter, a slurry inlet baffle, a rotating baffle, a mud discharge pipe, a spring flexible shaft and a slurry collection bucket connected in sequence through the slurry delivery pipe.

10. A method for simulating shield tunneling with adjustable posture in sandy soil, using the simulation device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Adjust the debugged shield machine model to zero position; Step 2: Prepare the test soil; Step 3: Install the displacement sensor; Step 4: Debug the monitoring system, set up the video acquisition equipment, and set up the collected data. Step 5: Turn on the simulation device and set the test parameters; Step 6: Carry out the test according to the design plan; Step 7: Collect and analyze experimental data.

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