Tunnel excavation device and testing method for centrifugal model test

Abstract

The present invention belongs to the field of centrifugal model testing, and specifically relates to a tunnel excavation device and testing method for centrifugal model testing, comprising a model box, a positioning system, an excavation simulation system, and a power system. The model box comprises a bottom plate and four side plates. The positioning system is provided with a middle partition assembly, which is disposed in the model box and divides the model box into an excavation half-zone and a monitoring half-zone. The excavation simulation system comprises a plexiglass tube and a stainless steel tube, one end of the plexiglass tube being sealed and the other end being hollow. The sealed end of the plexiglass tube is fixed to the front side plate, and the plexiglass tube is slidably nested in the stainless steel tube. A through hole is provided in the middle of the middle partition assembly for the stainless steel tube to pass through. A threaded rod is fixed to the end of the stainless steel tube away from the front side plate. The power system is provided with a stainless steel wire, and the threaded rod is connected to the power system through a stainless steel wire transmission. The present invention can realistically reproduce the stress characteristics of the tunnel lining and the damage morphology of the excavation surface during tunnel excavation.

Description

Technical Field

[0001] The invention belongs to the field of centrifugal model testing, and in particular relates to a tunnel excavation device and a testing method for centrifugal model testing. Background Art

[0002] Tunnel engineering is a structure built underground, underwater, or in a mountain, where railways or roads are laid for the passage of motor vehicles. In order to study the stress and deformation characteristics of tunnels under different geological conditions, indoor test simulation studies are often required. Centrifuge model testing, as a better test technology, is widely used in various geotechnical engineering simulation tests. This technology places the model in a high-speed rotating centrifuge, simulates different gravity fields by controlling the speed, and then reduces the model to 1 / n of the prototype. Since the centrifuge model test can simulate the stress field of the prototype and the materials used are the same as the prototype, the stress-strain and deformation instability laws of the model are almost exactly the same as those of the prototype. Centrifuge model testing technology has become the preferred test method for solving complex geotechnical problems due to its reliability, time and cost-effectiveness.

[0003] my country's geotechnical centrifuge testing technology started relatively late, but has developed rapidly in the past two or three decades. Centrifuge simulation testing technology has also made great progress. The performance of centrifuges has become better and better, the power has become larger and larger, and the performance of various auxiliary equipment has become more and more perfect. In addition, in order to meet the requirements of various tests, researchers have developed various auxiliary test devices. Taking tunnel excavation as an example, the patent with the authorization number "CN215599161U" and the name "A test device for simulating underwater tunnel excavation in a high centrifugal field" discloses a test device for simulating tunnel excavation. The test device includes a model box, a tunnel model tube, a segmented airbag, an air valve and other devices. The device simulates the size and thickness of the tunnel excavation surface by controlling the gas content in the airbag in segments. However, the device has the following main shortcomings: (1) Under high gravity, the strength of the airbag is often insufficient and it is easy to rupture; (2) The sealing of the connection between the airbag and the air valve is also difficult to ensure, and leakage and other phenomena are very likely to occur under high gravity, which leads to test failure; (3) The gas in the airbag will be unevenly distributed under the action of high gravity. Taking a circular tunnel as an example, there will be more gas at the bottom and less gas at the top, which makes it difficult to simulate the real tunnel cross-section.

[0004] Therefore, how to develop a test device that can simulate the entire process of tunnel excavation is an urgent problem to be solved in centrifuge model testing. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, the present invention discloses a tunnel excavation device and testing method for centrifugal model testing. This device uses a drive motor to pull a stainless steel sleeve to simulate stratum loss, enabling segmented excavation of tunnels under high gravity fields and solving the problem of precisely controlling stratum loss rates. To achieve these objectives, the present invention specifically discloses the following technical solutions:

[0006] A tunnel excavation device and testing method for centrifugal model testing, comprising a model box, a positioning system, an excavation simulation system and a power system. The model box is a box structure with an open top, comprising a bottom plate and four side plates. The positioning system is provided with a middle partition assembly, which is arranged in the model box to separate the model box into an excavation half area and a monitoring half area. The excavation simulation system comprises an organic glass tube and a stainless steel tube, one end of the organic glass tube is sealed and the other end is hollow. The sealed end of the organic glass tube is fixed to the front side plate of the model box, and the organic glass tube is slidably nested in the stainless steel tube. A through hole for the stainless steel tube to pass through is provided in the middle of the middle partition assembly, and a threaded rod is fixed inside the end of the stainless steel tube away from the front side plate. The power system is provided with stainless steel wire, and the threaded rod is connected to the power system through the stainless steel wire transmission.

[0007] Furthermore, the model box is made of aerospace aluminum alloy, and a rectangular hollow area is provided in the middle of the front side panel of the model box. A plexiglass plate is installed in the rectangular hollow area for observing and recording the displacement and deformation of the soil during the test. The front end of the plexiglass tube is sealed and fixed to the plexiglass plate by bolts.

[0008] Furthermore, a groove is provided in the middle of the left and right side plates of the model box, and plug-in protrusions are provided at both ends of the middle partition assembly, and the middle partition assembly is plugged into the groove through the plug-in protrusions.

[0009] Furthermore, the positioning system also includes a fixed threaded rod and a support platform. A fixed threaded rod vertically fixed to the bottom plate of the model box is provided directly behind the middle partition assembly. The support platform is provided at the top end of the fixed threaded rod. The top of the support platform is provided with an arc groove concentric with the through hole.

[0010] Furthermore, the power system includes a driving motor, a guide wheel bracket, a guide wheel, a fixed pulley and a stainless steel wire. The rear side panel of the model box is provided with a reserved hole. The guide wheel bracket is installed on the outer surface of the rear side panel through the reserved hole. The guide wheel is rotatably set on the guide wheel bracket. The driving motor is set on the bottom plate of the model box. The fixed pulley is fixedly installed on the output shaft of the driving motor. The center of the stainless steel pipe, the guide wheel and the fixed pulley are maintained in the same vertical plane. One end of the stainless steel wire is fixedly connected to the threaded rod, and the other end of the stainless steel wire is wrapped around the guide wheel and wound in the fixed pulley.

[0011] Furthermore, the reserved holes are three vertically arranged long holes, and the guide wheel bracket is set in the long holes on the left and right sides through adjusting bolts, and the installation height of the guide wheel bracket is changed by adjusting the bolts.

[0012] Furthermore, the bottom plate of the model box is provided with a model box fixing hole for fixing the model box on the centrifuge.

[0013] Furthermore, the top of the left and right side panels of the excavation half area of ​​the model box are provided with bracket reserved holes for installing sensor brackets, and the top of the left and right side panels of the monitoring half area of ​​the model box are provided with high-definition camera installation holes for installing high-definition cameras.

[0014] Furthermore, it also includes soil pressure sensors, pore water pressure sensors, inclinometers and tunnel lining sensors. The soil pressure sensors, pore water pressure sensors, inclinometers and tunnel lining sensors are all pre-buried in the soil of the excavation half area, and the strain gauges of the tunnel lining sensors are posted on the surface of the organic glass tube.

[0015] A method for testing tunnel excavation for centrifugal model testing, using the above-mentioned test apparatus, comprises the following steps:

[0016] S1. Determine the tunnel burial depth, select the appropriate middle baffle assembly and the corresponding cross-sectional form of the middle baffle assembly according to the burial depth, and adjust the support platform and the directional wheel bracket to a matching height;

[0017] S2. Bury soil in the excavated half of the model box to a height equal to the tunnel floor elevation;

[0018] S3. Bury sensors inside the soil. Depending on the test conditions, bury the soil pressure sensor, pore water pressure sensor, and inclinometer inside the soil.

[0019] S4. Install the tunnel lining sensor. Attach the strain gauge to the plexiglass tube according to the test conditions.

[0020] S5. Assemble the excavation simulation system. Secure the plexiglass tube and plexiglass plate with bolts and nuts. Nest the plexiglass tube inside the stainless steel tube. Secure a threaded rod to one end of the stainless steel tube.

[0021] S6. Assemble the power system and connect the drive motor to the stainless steel tube using stainless steel wire.

[0022] S7. Bury the remaining soil at a depth appropriate to the test conditions and cover the tunnel excavation system with suitable test soil.

[0023] S8. Install the sensor bracket. Fix the sensor bracket with the laser displacement meter above the excavation half area.

[0024] S9. Start the test, hoist the model box onto the centrifuge main unit and secure it with bolts, turn on the centrifuge, turn on the sensor acquisition equipment, turn on the high-definition camera to observe the excavation status, start the drive motor, wait until the excavation reaches the target position, turn off the motor, turn off the centrifuge main unit, and end the test.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention can simulate the actual stress environment of a tunnel by utilizing the centrifugal force generated by the high-speed rotation of the centrifuge. The device of the present invention can realistically reproduce the stress characteristics of the tunnel lining and the damage morphology of the excavation surface during tunnel excavation.

[0027] 2. The intermediate baffle assembly of the present invention can be freely assembled and customized to different tunnel cross-sections to simulate the excavation process of highway tunnels (horseshoe cross-section) and subway tunnels (circular cross-section). In addition, by changing the position of the first intermediate baffle, tunnels of different burial depths can be simulated.

[0028] 3. The drive motor of the present invention is driven by electricity, and the speed of the drive motor can be changed by changing the voltage, thereby achieving different excavation speeds;

[0029] 4. The present invention can simulate different stratum loss rates by changing the thickness of the stainless steel pipe in the excavation system, and explore the impact of the stratum loss rate on tunnel instability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the main structure of the tunnel excavation device of the present invention;

[0031] Figure 2 A top view of the tunnel excavation device of the present invention;

[0032] Figure 3 This is a schematic diagram of the back structure of the tunnel excavation device of the present invention;

[0033] Figure 4 This is a schematic diagram of the support platform structure of the present invention;

[0034] Figure 5 This is a schematic diagram of the partition assembly plug-in connection of the present invention;

[0035] Figure 6 This is a schematic structural diagram of the first middle partition of the present invention;

[0036] Figure 7 This is a schematic diagram of the structure of the second middle partition of the present invention;

[0037] Figure 8 This is a schematic diagram of the connection between the organic glass tube and the organic glass plate of the present invention;

[0038] Figure 9 This is a schematic diagram of the installation of the guide wheel bracket of the present invention;

[0039] Figure 10 This is a schematic diagram of the model box of the present invention in the working state of the centrifuge.

[0040] Among them, 1: bolts and nuts; 2: organic glass plate; 3: model box fixing holes; 4: organic glass tube; 5: middle partition assembly; 5a: first middle partition; 5b: second middle partition; 6: stainless steel tube; 7: high-definition camera; 8: stainless steel wire; 9: reserved hole; 10: 304 high-strength threaded rod; 11: reserved hole; 12: guide wheel; 13: support platform; 14: fixed pulley; 15: drive motor; 16: guide wheel bracket; 17: fixed threaded rod. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] Example 1

[0043] like Figure 1-10 As shown, the present invention provides a tunnel excavation device for centrifugal model testing, including a model box, a positioning system, a power system, a positioning system, and an excavation simulation system.

[0044] The model box of the present invention is composed of a high-strength aerospace aluminum alloy. It is used to bury the test soil and serves as the foundational platform for the power system, positioning system, and excavation simulation system. It includes four side panels (front, back, left, and right) and a bottom panel. The front side panel has four circular holes and a rectangular hole for observation. A plexiglass plate 2 is secured to the rectangular holes in the front side panel with bolts and nuts 1, facilitating observation and recording of soil displacement and deformation during the test. The bottom panel has model box fixing holes 3 for securing the box to the centrifuge mainframe. The positioning system includes a central partition assembly 5, which is positioned within the model box and divides it into an excavation section and a monitoring section. The excavation section is used to bury the test soil, while the monitoring section is used to monitor the test progress. Bracket holes 9 are provided at the top of the left and right side panels of the excavation section for mounting sensor brackets. The top of the left and right side panels of the monitoring section of the model box also have mounting holes for a high-definition camera 7. In this embodiment, the high-definition camera 7 is secured to the left panel of the monitoring section. A pre-reserved hole 11 is provided on the rear side panel.

[0045] Specifically, the excavation simulation system includes a plexiglass tube 4 and a stainless steel tube 6. The plexiglass tube 4 is used to simulate the tunnel lining, with one end sealed and the other end hollow. The stainless steel tube 6 is used to simulate the ground loss caused by tunnel excavation. The sealed end of the plexiglass tube 4 is fixed to the plexiglass plate 2 via bolts and nuts 1. The tube body of the plexiglass tube 4 slides and nests in the stainless steel tube 6. A through hole for the stainless steel tube 6 is provided in the middle of the middle partition assembly 5. The stainless steel tube 6 has symmetrical mounting holes at one end away from the front side plate. 304 high-strength threaded rods 10 pass through the mounting holes of the stainless steel tube 6 and are locked and fixed with nuts. The power system is provided with stainless steel wires 8, and the 304 high-strength threaded rods 10 are connected to the power system through the stainless steel wires 8.

[0046] The positioning system also includes a fixed threaded rod 17 and a support platform 13. A fixed threaded rod 17 vertically fixed to the bottom plate of the model box is provided directly behind the middle partition assembly 5. The support platform 13 is provided at the top end of the fixed threaded rod, and the top of the support platform 13 is provided with an arc groove concentric with the through hole.

[0047] The power system includes a drive motor 15, a guide wheel bracket 16, a guide wheel 12, a fixed pulley 14 and a stainless steel wire 8. The guide wheel bracket 16 is installed on the outer surface of the rear side plate through the reserved hole 9. The guide wheel 12 is rotatably set on the guide wheel bracket 16. The center of the stainless steel tube 6, the center of the middle partition assembly 5 and the center of the fixed pulley 14 need to be kept on the same horizontal line. The drive motor 15 is set on the bottom plate of the model box. The fixed pulley 14 is fixedly installed on the output shaft of the drive motor 15. The center of the stainless steel tube 6, the guide wheel 12 and the fixed pulley 14 are kept in the same vertical plane. One end of the stainless steel wire 8 is fixedly connected to the 304 high-strength threaded rod 10, and the other end of the stainless steel wire 8 is wrapped around the guide wheel 12 and wound in the fixed pulley 14. The power system is powered by the drive motor 15 to drag the stainless steel tube 6 to move.

[0048] As a preferred embodiment of the present invention, a groove is provided in the middle of the front and rear side panels, plug-in protrusions are provided on both sides of the middle partition assembly 5, and the middle partition assembly 5 and the left and right side panels are combined through a "concave and convex" mortise and tenon structure.

[0049] Furthermore, the diaphragm assembly 5 includes a first diaphragm 5a and a second diaphragm 5b. The through-holes for the stainless steel tube 6 are provided in the first diaphragm 5a, and can be positioned differently depending on the tunnel cross-section. The second diaphragm 5b is positioned above and below the first diaphragm 5a. By properly assembling the diaphragm assembly 5, the height of the through-holes can be adjusted.

[0050] As a preferred embodiment of the present invention, the reserved holes 11 are three vertically arranged long holes, the guide wheel bracket 16 is set in the long holes on the left and right sides by adjusting bolts, and the installation height of the guide wheel bracket 16 is changed by adjusting bolts, the stainless steel wire 8 is passed through the middle long hole, and the guide wheel bracket 16 can be flexibly adjusted to a suitable height according to the reserved space of the reserved hole 11.

[0051] As a preferred embodiment of the present invention, it also includes an earth pressure sensor, a pore water pressure sensor, an inclinometer and a tunnel lining sensor. The earth pressure sensor, the pore water pressure sensor, the inclinometer and the tunnel lining sensor are all pre-buried in the soil of the excavation half area, and the strain gauge of the tunnel lining sensor is posted on the surface of the organic glass tube 4.

[0052] Example 2

[0053] This embodiment discloses a tunnel excavation test method for simulating a centrifugal model test using the test apparatus in the above example, comprising the following steps:

[0054] S1. Determine the tunnel burial depth, select the appropriate middle diaphragm assembly 5 and the corresponding cross-sectional form of the middle diaphragm assembly 5 according to the burial depth, assemble the middle diaphragm assembly 5 to the appropriate height, and adjust the support platform 13 and the directional wheel bracket 16 to the appropriate height;

[0055] S2. Bury the soil in the excavated half of the model box to the same height as the tunnel bottom elevation. Bury sensors inside the soil. Depending on the test conditions, embed any sensing equipment such as soil pressure sensors, pore water pressure sensors, and inclinometers that may be used inside the soil.

[0056] S3. Install the tunnel lining sensor and stick the strain gauge on the organic glass tube 4 according to the test conditions;

[0057] S4. Assemble the excavation simulation system, fix the organic glass tube 4 and the organic glass plate 2 together with the bolts and nuts 1, nest the organic glass tube 4 inside the stainless steel tube 6, and pass the 304 high-strength threaded rod 10 through the mounting hole of the stainless steel tube 6 and lock it with the nuts;

[0058] S5. Assemble the power system, install the fixed pulley 14 on the output shaft of the drive motor 15, and connect the fixed pulley 14 and the stainless steel tube 6 through the stainless steel wire 8 through the guide wheel 12, and ensure that the stainless steel tube 6 and the guide wheel 12 are on the same horizontal line;

[0059] S6. Bury the remaining soil at a depth that is appropriate for the test conditions and cover the tunnel excavation system with suitable test soil.

[0060] S7. Install the sensor bracket, install the sensor bracket with the laser displacement meter on the model box through the bracket reserved hole 9, and fix it above the excavation half area;

[0061] S8, start the test, hoist the model box to the centrifuge host (such as Figure 10 As shown), turn on the centrifuge, turn on the sensor acquisition equipment, turn on the high-definition camera to observe the excavation status, start the drive motor 15, wait until the excavation reaches the target position, turn off the drive motor 15, turn off the centrifuge host, and end the test.

[0062] The key to the success of this test device is whether the drive motor 15 can provide a large enough pulling force. The force on the tunnel during the pulling process is mainly the friction caused by the surrounding soil. Assume that the tunnel diameter is 10cm. The tunnel depth is 15cm, the tunnel length is 30cm, and the surrounding soil is sand (density 1.8×10 3 kg / m 3 ), the similarity ratio is 50. Then the earth pressure above the tunnel is:

[0063] F = mg = pvg = 1.8 × 10 3 ×0.1×0.15×0.3×10=81kN (1) The friction force is:

[0064] f=μF=0.1×81=8.1kN (2) The friction force under the action of 50 times the centrifugal force is:

[0065] f 50 =N×f=50×8.1=405kN(3) Simplify the circular tunnel into a square tunnel, then the friction force f on the four surfaces is 总 for:

[0066] f 总 =4×f 50 =4×405=1620kN(4)

[0067] Taking the Weisheng 75ZY drive motor available on the market as an example, the motor torque M is 610kg / cm, which is approximately equal to 6100kN / cm. The motor shaft radius is 1.5cm, so the torque N that the motor can provide is 4066kN, N>f 总 , it can be seen that, in theoretical terms, the driving motor can pull the stainless steel pipe.

[0068] In fact, considering factors such as the passive earth pressure coefficient and the circular cross-section of the tunnel, the friction force on the tunnel should be completely smaller than this value. In addition, in order to ensure the smooth pulling out of the tunnel model, Vaseline will be applied to the outside of the steel cylinder to reduce the friction coefficient.

[0069] The above description is merely a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A tunnel excavation device for centrifugal model testing, characterized in that: It includes a model box, a positioning system, an excavation simulation system and a power system. The model box is a box structure with an open top, including a bottom plate and four side plates. The positioning system is provided with a middle partition assembly, and the middle partition assembly is arranged in the model box to separate the model box into an excavation half area and a monitoring half area. The excavation simulation system includes an organic glass tube and a stainless steel tube. One end of the organic glass tube is sealed and the other end is hollow. The sealed end of the organic glass tube is fixed to the front side plate of the model box, and the organic glass tube is slidably nested in the stainless steel tube. A through hole for the stainless steel tube to pass through is provided in the middle of the middle partition assembly. A threaded rod is fixed inside the end of the stainless steel tube away from the front side plate. The power system is provided with stainless steel wire, and the threaded rod is connected to the power system through the stainless steel wire transmission.

2. A tunnel excavation device for centrifugal model testing according to claim 1, characterized in that: The model box is made of aerospace aluminum alloy. A rectangular hollow area is provided in the middle of the front side panel of the model box. A plexiglass plate is installed in the rectangular hollow area for observing and recording the displacement and deformation of the soil during the test. The front end of the plexiglass tube is sealed and fixed to the plexiglass plate by bolts.

3. The tunnel excavation device for centrifugal model testing according to claim 1, characterized in that: A groove is provided in the middle of the left and right side plates of the model box, and plug-in protrusions are provided at both ends of the plug-in of the middle partition assembly, and the middle partition assembly is plugged into the groove through the plug-in protrusions.

4. The tunnel excavation device for centrifugal model testing according to claim 2, characterized in that: The positioning system also includes a fixed threaded rod and a support platform. A fixed threaded rod vertically fixed to the bottom plate of the model box is provided directly behind the middle partition assembly. The support platform is provided at the top end of the fixed threaded rod. The top of the support platform is provided with an arc groove concentric with the through hole.

5. The tunnel excavation device for centrifugal model testing according to claim 4, characterized in that: The power system includes a driving motor, a guide wheel bracket, a guide wheel, a fixed pulley and a stainless steel wire. The rear side panel of the model box is provided with a reserved hole. The guide wheel bracket is installed on the outer surface of the rear side panel through the reserved hole. The guide wheel is rotatably set on the guide wheel bracket. The driving motor is set on the bottom plate of the model box. The fixed pulley is fixedly installed on the output shaft of the driving motor. The center of the stainless steel pipe, the guide wheel and the fixed pulley are maintained in the same vertical plane. One end of the stainless steel wire is fixedly connected to the threaded rod, and the other end of the stainless steel wire is wrapped around the guide wheel and wound in the fixed pulley.

6. The tunnel excavation device for centrifugal model testing according to claim 5, characterized in that: The reserved holes are three vertically arranged long holes. The guide wheel bracket is arranged in the long holes on the left and right sides through adjusting bolts, and the installation height of the guide wheel bracket is changed by adjusting the bolts.

7. The tunnel excavation device for centrifugal model testing according to claim 1, characterized in that: The bottom plate of the model box is provided with a model box fixing hole for fixing the model box on the centrifuge.

8. The tunnel excavation device for centrifugal model testing according to claim 6, characterized in that: The top of the left and right side panels of the excavation half of the model box are provided with bracket reserved holes for installing sensor brackets, and the top of the left and right side panels of the monitoring half of the model box are provided with high-definition camera installation holes for installing high-definition cameras.

9. The tunnel excavation device for centrifugal model testing according to claim 8, characterized in that: It also includes soil pressure sensors, pore water pressure sensors, inclinometers and tunnel lining sensors. The soil pressure sensors, pore water pressure sensors, inclinometers and tunnel lining sensors are all pre-buried in the soil of the excavation half area, and the strain gauges of the tunnel lining sensors are posted on the surface of the organic glass tube.

10. A testing method using the tunnel excavation device for centrifugal model testing according to claim 9, characterized in that: The steps are as follows: S1. Determine the tunnel burial depth, select the appropriate middle baffle assembly and the corresponding cross-sectional form of the middle baffle assembly according to the burial depth, and adjust the support platform and guide wheel bracket to a matching height; S2. Bury soil in the excavated half of the model box to a height equal to the tunnel floor elevation; S3. Bury sensors inside the soil. Depending on the test conditions, bury the soil pressure sensor, pore water pressure sensor, and inclinometer inside the soil. S4. Install the tunnel lining sensor. Attach the strain gauge to the plexiglass tube according to the test conditions. S5. Assemble the excavation simulation system. Secure the plexiglass tube and plexiglass plate with bolts and nuts. Nest the plexiglass tube inside the stainless steel tube. Secure a threaded rod to one end of the stainless steel tube. S6. Assemble the power system and connect the drive motor to the stainless steel tube using stainless steel wire. S7. Bury the remaining soil at a depth appropriate to the test conditions and cover the tunnel excavation system with suitable test soil. S8. Install the sensor bracket. Fix the sensor bracket with the laser displacement meter above the excavation half area. S9. Start the test, hoist the model box onto the centrifuge main unit and secure it with bolts, turn on the centrifuge, turn on the sensor acquisition equipment, turn on the high-definition camera to observe the excavation status, start the drive motor, wait until the excavation reaches the target position, turn off the motor, turn off the centrifuge main unit, and end the test.

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