Transparent soil experimental device

Abstract

The invention discloses a transparent soil experiment device, and relates to the technical field of soil experiments.The transparent soil experiment device comprises a transparent soil experiment platform, a seepage pressurization module, a vertical pressurization module, a camera module and an information collecting and processing module.The transparent soil experiment platform comprises a base, a portal frame and a light source structure, and a model box is arranged on the base; a transparent soil model is arranged in the model box, a cross beam is arranged above the portal frame corresponding to the model box, and the light source structure corresponds to the model box; the seepage pressurization module is communicated with the model box; the vertical pressurizing module is mounted on the portal frame; the camera module is arranged on the side of the model box. According to the invention, the complex stress state that a dam body simultaneously bears an overlying load and a lateral water head difference in projects such as water conservancy embankment can be truly represented, and test research on geometric characteristic and hydraulic characteristic changes of a soil body caused by fine particle loss under the action of circulating seepage-stress coupling can be carried out.

Description

Technical Field

[0001] This invention relates to the field of soil testing technology, and in particular to a transparent soil testing apparatus. Background Technology

[0002] The safety of water conservancy projects such as seawalls and river embankments is one of their most critical indicators. These projects are subjected to complex hydrological environments and frequent tidal action over long periods, making them highly susceptible to water erosion and seepage, which can lead to slope instability and even dam failure. Among these, piping is a significant cause of damage to the internal structure of embankments, and exploring its microscopic mechanisms and evolution is of great importance for disaster prevention in engineering projects.

[0003] In recent years, transparent soil model testing technology, combined with particle image velocimetry or planar laser-induced fluorescence technology, has become an important means in the field of geotechnical engineering for observing the internal seepage field of soil, capturing the migration trajectory of fine particles, and analyzing the evolution of pore channels, thanks to its non-invasive and full-field visualization advantages.

[0004] However, existing transparent soil experimental models are mostly limited to single fluid seepage simulations, and cannot realistically reproduce the complex stress state coupled with overlying loads and lateral head differences in dam engineering. Furthermore, they have few measurable parameters, resulting in insufficient accuracy in calculating simulation results. Summary of the Invention

[0005] The main objective of this invention is to propose a transparent soil experimental device, which aims to solve the problems in the existing technology that cannot realistically reproduce the complex stress state coupled with the overlying load and lateral head difference in dam engineering, as well as the limited number of measurable parameters and insufficient accuracy of simulation results.

[0006] To achieve the above objectives, the present invention proposes a transparent soil experimental apparatus, comprising:

[0007] A transparent soil experimental platform includes a base, a gantry frame, and a light source structure. A model box is set on the base, and a transparent soil model is set inside the model box. A crossbeam is set above the model box on the gantry frame, and the light source structure is set in relation to the model box and is used to illuminate the transparent soil model. A seepage pressurization module, which is connected to the model box and is used to provide a horizontal seepage field for the model box; A vertical pressurization module is installed on the gantry and is used to apply a vertical load to the transparent soil model inside the model box; A camera module is disposed on the side of the model box and is used to capture images of the transparent soil model; The information acquisition and processing module, the seepage pressurization module, the vertical pressurization module and the camera module are all electrically connected to the information acquisition and processing module.

[0008] In one embodiment, a rigid loading block is provided on the top of the transparent soil model, and the vertical pressurization module includes a vertical pusher. The vertical pusher is installed on the crossbeam, and the output end of the vertical pusher pushes the rigid loading block down through a telescopic force transmission rod to apply a vertical load to the transparent soil model. A pressure sensor is provided on the telescopic force transmission rod, and both the pressure sensor and the vertical pusher are electrically connected to the information acquisition and processing module.

[0009] In one embodiment, a displacement sensor is provided on the vertical pusher or the crossbeam. The displacement sensor is used to detect the vertical settlement of the transparent soil model, and the displacement sensor is electrically connected to the information acquisition and processing module.

[0010] In one embodiment, the model box includes an inlet side and an outlet side. The seepage pressurization module includes an oil storage tank, an upstream oil transfer tank, a downstream oil collection tank, and a water distribution component. The upstream oil transfer tank is connected to the oil storage tank via an inlet pipe, and an oil pump is installed on the inlet pipe. The upstream oil transfer tank is connected to the water distribution component, which is used to divide the liquid in the upstream oil transfer tank into multiple branches and connect them to the inlet side respectively. The outlet side is connected to the downstream oil collection tank.

[0011] In one embodiment, the water distribution assembly includes a water distributor and a plurality of water distribution pipes connected to the water distributor. The water distributor is connected to the upstream oil tank via an oil pipeline. A multi-functional valve is provided on the oil pipeline. The multi-functional valve is used to cut off the oil pipeline, adjust the flow rate of the oil pipeline, or prevent backflow in the oil pipeline. The multi-functional valve can collect the flow rate and velocity of the liquid flowing through the oil pipeline. And / or, the upstream oil tank is connected to the oil storage tank via an overflow pipe, and the overflow pipe is used to control the liquid level in the upstream oil tank to be maintained at a preset height.

[0012] In one embodiment, both the upstream oil tank and the downstream oil collection tank are equipped with level sensors, and both level sensors are electrically connected to the information acquisition and processing module.

[0013] In one embodiment, there are multiple light source structures. A light-transmitting hole is provided on the base corresponding to the bottom observation area of ​​the model box. At least one light source structure is disposed at the bottom of the model box and is disposed corresponding to the light-transmitting hole. The remaining light source structures are disposed on the gantry frame and located above the model box. The light source structure includes a driving component and a light source component connected to the driving component. The driving component is used to drive the light source component to move relative to the model box.

[0014] In one embodiment, the bottom of the model box is provided with a bottom slide rail, and the driving component includes a slider and a telescopic bracket. The slider of the light source structure located at the top of the model box is slidably connected to the crossbeam, and the slider of the light source structure located at the bottom of the model box is slidably connected to the bottom slide rail. The slider is connected to the light source component through the telescopic bracket, and the telescopic bracket is used to drive the light source component to move toward or away from the model box.

[0015] In one embodiment, the model box is made of transparent material and is divided into an upstream buffer zone, a middle test filling zone, and a downstream monitoring and collection zone along the internal fluid flow direction. The upstream buffer zone is equipped with an inlet buffer layer and a porous flow equalization plate to eliminate turbulence at the fluid inlet and disperse pore water pressure. A filter tank extends downwards from the bottom of the downstream monitoring and collection zone, containing a filter screen. The middle test filling zone contains the transparent soil model, and a guide plate is installed at the toe of the transparent soil model. The discharge end of the guide plate extends into the filter screen to receive and guide the eroded transparent soil particles. A hook is fixed to the crossbeam, and a tension sensor is suspended from the lower end of the hook. The filter screen is connected to the tension sensor via a rope. The tension sensor is electrically connected to the information acquisition and processing module for real-time weighing of the collected lost particles.

[0016] In one embodiment, the top of the model box is open, and the transparent soil experimental platform also includes an upper cover plate adapted to the opening. The upper cover plate is provided with a sealing buckle on its outer periphery. The sealing buckle is used to cooperate with the edge of the opening to seal the model box. The upper cover plate is also provided with a vacuum saturation interface, which is used to connect with an external vacuum pumping device to evacuate the model box.

[0017] In this invention, a model box is set on a base, and a vertical pressurization module is set on top of the model box to provide a vertical load for the transparent soil model inside the model box. Then, a horizontal seepage field is provided through a seepage pressurization module, and the transparent soil model is illuminated by a light source structure. A camera device is used to capture the particle movement trajectory of the transparent soil model under pressure during the seepage process. This invention can realistically reproduce the complex stress state of dams in water conservancy projects such as embankments, where the dam body is simultaneously subjected to the combined action of overlying loads and lateral head differences. It can conduct experimental research on the changes in soil geometric and hydraulic properties caused by fine particle loss under cyclic seepage-stress coupling, improve the similarity of engineering prototypes, and enhance the representativeness and reliability of model tests. Meanwhile, by using a transparent soil medium with a matching refractive index, combined with uniform lighting from the light source structure and real-time imaging from the camera module, the entire field of particle migration, erosion channel formation, and local deformation evolution processes within the model can be visualized and observed. Furthermore, by combining the information acquisition and processing module, parameters such as vertical pressure, seepage pressure, seepage velocity, seepage flow rate, and particle erosion quality can be simultaneously acquired and fused for analysis. This enables coupled calculation of mechanical parameters and image data, improving the physical similarity, data accuracy, and repeatability of the model test, enhancing the realism and quantitative analysis capabilities of engineering simulation. Additionally, the modular structural design facilitates the expansion of different loading forms and observation methods, further enhancing the applicability and engineering application value of the device. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a transparent soil experimental device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the model box of the transparent soil experimental device provided in an embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of a transparent soil experimental device provided in an embodiment of the present invention; Figure 4 A top view of the model box of the transparent soil experimental device provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the light source structure of a transparent soil experimental device provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the upper cover plate of a transparent soil experimental device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a detachable mold for a transparent soil experimental apparatus provided in an embodiment of the present invention.

[0020] Explanation of icon numbers: 100. Transparent Soil Experimental Apparatus; 10. Transparent Soil Experimental Platform; 11. Base; 111. Light Transmitting Hole; 12. Gantry Frame; 121. Crossbeam; 122. Hook; 123. Tension Sensor; 124. Suspension Rope; 13. Light Source Structure; 131. Drive Component; 1311. Sliding Component; 1312. Telescopic Support; 132. Light Source Component; 133. Universal Joint; 14. Model Box; 141. Transparent Soil Model; 142. Rigid Loading Block; 143. Inlet Side; 144. Outlet Side; 145. Upstream Buffer Zone; 1451. Liquid Inlet Buffer Layer; 1452. Porous Flow Equalization Plate; 146. Middle Experimental Filling Zone; 147. Downstream Monitoring and Collection Zone; 1471. Fine Particle Collection Device; 1472. Filter Screen; 1473. Filter Filter tank; 148. Guide plate; 20. Percolation pressurization module; 21. Oil storage tank; 22. Upstream oil tank; 221. Inlet pipe; 222. Inlet pump; 23. Downstream oil collection tank; 231. Outlet pipe; 232. Throttling valve; 24. Water distribution assembly; 241. Water distributor; 242. Water distribution pipe; 243. Multifunctional valve; 25. Overflow pipe; 26. Liquid level sensor; 27. Oil supply pipe; 30. Vertical pressurization module; 31. Vertical pusher; 32. Telescopic force transmission rod; 33. Displacement sensor; 40. Camera module; 50. Information acquisition and processing module; 60. Bottom slide rail; 70. Top cover plate; 71. Sealing latch; 72. Vacuum saturation interface; 80. Demountable mold; 90. Positioning plate; 91. Limiting groove; 92. Positioning component.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] Existing transparent soil experimental models are mostly limited to single fluid seepage simulations, neglecting the coupling effect of overburden loads, and cannot realistically reproduce the complex stress state of overburden loads coupled with lateral head differences in dam engineering. Furthermore, they have few measurable parameters, resulting in insufficient accuracy in the simulation results.

[0026] To address the above problems, this invention proposes a transparent soil experimental device 100.

[0027] Please combine Figures 1 to 7 The transparent soil experimental device 100 of this embodiment includes a transparent soil experimental platform 10, a seepage pressurization module 20, a vertical pressurization module 30, a camera module 40, and an information acquisition and processing module 50. The transparent soil experimental platform 10 includes a base 11, a gantry frame 12, and a light source structure 13. A model box 14 is set on the base 11, and a transparent soil model 141 is set inside the model box 14. A crossbeam 121 is set above the model box 14 corresponding to the gantry frame 12. The light source structure 13 is set above the model box 14 and... The transparent soil model 141 is illuminated; the seepage pressurization module 20 is connected to the model box 14 and is used to provide a horizontal seepage field for the model box 14; the vertical pressurization module 30 is installed on the gantry 12 and is used to apply a vertical load to the transparent soil model 141 inside the model box 14; the camera module 40 is set on the side of the model box 14 and is used to capture images of the transparent soil model 141; the seepage pressurization module 20, the vertical pressurization module 30 and the camera module 40 are all electrically connected to the information acquisition and processing module 50.

[0028] It should be noted that this experimental platform is not limited to basic transparent soil imaging, but is also widely applicable to various complex geotechnical engineering model tests. Specifically, the transparent soil medium in the transparent soil model 141 can be selected from materials such as fused silica sand, silica gel particles, and amorphous silica powder. The pore fluid is a mixed mineral oil or calcium bromide solution with a refractive index that is strictly matched with the above-mentioned solid phase medium to achieve a high degree of transparency of the model. Tracer particles or solvent staining agents can be added for the visualization and tracking of flow and deformation fields.

[0029] In the technical solution of this invention, a model box 14 is set on the base 11, and a vertical pressurization module 30 is set on the top of the model box 14 to provide a vertical load for the transparent soil model 141 inside the model box 14. Then, a horizontal seepage field is provided through the seepage pressurization module 20, and the transparent soil model 141 is illuminated by the light source structure 13. The particle movement trajectory of the transparent soil model 141 under pressure during the seepage process is captured by a camera device. This invention can realistically reproduce the complex stress state of dams in water conservancy projects such as dikes, where the dam body is simultaneously subjected to the combined action of overlying load and lateral head difference. It can conduct experimental research on the changes in soil geometric and hydraulic properties caused by fine particle loss under cyclic seepage-stress coupling. Compared with experimental devices that only use single loading or single seepage control, this solution can simultaneously simulate the coupling effect of vertical load and horizontal seepage, improve the similarity of engineering prototypes, and enhance the representativeness and reliability of model tests. Simultaneously, by using a transparent soil medium with a matching refractive index, combined with uniform lighting from the light source structure 13 and real-time imaging from the camera module 40, the entire process of particle migration, erosion channel formation, and local deformation evolution within the model can be visualized and observed. Furthermore, by combining the information acquisition and processing module 50, parameters such as vertical pressure, seepage pressure, seepage velocity, seepage flow rate, and particle erosion quality can be simultaneously acquired and fused for analysis. This enables coupled calculation of mechanical parameters and image data, improving the physical similarity, data accuracy, and repeatability of the model test. It can more accurately reproduce the seepage failure and erosion evolution process inside the dam, enhancing the realism and quantitative analysis capabilities of the engineering simulation. Moreover, due to the modular structural design, it is easy to expand different loading forms and observation methods, further enhancing the applicability and engineering application value of the device.

[0030] Understandably, the information acquisition and processing module 50 adopts mature terminal machines, host computers or computer equipment in the existing technology.

[0031] In one embodiment, a rigid loading block 142 is provided on the top of the transparent soil model 141. The vertical pressurization module 30 includes a vertical pusher 31, which is installed on the crossbeam 121. The output end of the vertical pusher 31 pushes the rigid loading block 142 down through a telescopic force transmission rod 32 to apply a vertical load to the transparent soil model 141. A pressure sensor is provided on the telescopic force transmission rod 32. Both the pressure sensor and the vertical pusher 31 are electrically connected to the information acquisition and processing module 50.

[0032] By setting a rigid loading block 142 on the top of the transparent soil model 141, the vertical load is uniformly transmitted to the surface of the transparent soil model 141 via the telescopic force transmission rod 32, avoiding interference with the test results caused by local stress concentration or eccentric loading, thereby improving the stability and uniformity of vertical stress. The vertical pusher 31 is installed on the crossbeam 121 and loaded through the telescopic force transmission rod 32, which can realize precise control of the loading stroke and continuous adjustment of the loading process, making the consolidation and deformation process of the model under different stress paths controllable. At the same time, a pressure sensor is set on the telescopic force transmission rod 32 to monitor the actual vertical load applied to the model in real time and synchronize the data with the information acquisition and processing module 50 to realize closed-loop control and error correction of the loading force, thereby improving the accuracy and repeatability of load application.

[0033] Specifically, the vertical pushing component 31 can be an electro-hydraulic jack, which not only enables precise vertical load control but also integrates a pressure sensor to directly acquire pressure data. It should be emphasized that the electro-hydraulic jack can be a mature product from the existing technology and is not an improvement in this application.

[0034] In one embodiment, a displacement sensor 33 is provided on the vertical pusher 31 or the crossbeam 121. The displacement sensor 33 is used to detect the vertical settlement of the transparent soil model 141, and the displacement sensor 33 is electrically connected to the information acquisition and processing module 50.

[0035] Furthermore, the probe of the displacement sensor 33 abuts against the upper surface of the rigid loading block 142 to monitor the vertical settlement deformation of the soil under load in real time, thereby achieving precise control and response monitoring of the vertical stress state of the soil. This direct contact measurement method eliminates the error interference of the elastic deformation of the gantry 12 and the elastic force transmission rod itself on the measurement results, ensuring the authenticity of the settlement data.

[0036] In one embodiment, the model box 14 includes an inlet side 143 and an outlet side 144. The seepage pressurization module 20 includes an oil storage tank 21, an upstream oil delivery tank 22, a downstream oil collection tank 23, and a water distribution component 24. The upstream oil delivery tank 22 is connected to the oil storage tank 21 through an inlet pipe 221. An oil pump 222 is installed on the inlet pipe 221. The upstream oil delivery tank 22 is connected to the water distribution component 24. The water distribution component 24 is used to divide the liquid in the upstream oil delivery tank 22 into multiple branches and connect them to the inlet side 143 respectively. The outlet side 144 is connected to the downstream oil collection tank 23.

[0037] By setting up an inlet side 143 and an outlet side 144 on both sides of the model box 14, and forming a closed-loop seepage pressurization system consisting of an oil storage tank 21, an upstream oil delivery tank 22, a water distribution component 24, and a downstream oil collection tank 23, the oil pump 222 stably delivers the liquid to the upstream oil delivery tank 22, and then the liquid is diverted by the water distribution component 24 into the inlet side 143 of the model box 14. This establishes a stable and controllable horizontal seepage field inside the transparent soil model 141, ensuring the continuity and uniformity of the seepage boundary conditions. The water distribution component 24 divides the liquid in the upstream oil delivery tank 22 into multiple branches that are connected to the inlet side 143, which can effectively reduce the local velocity concentration and turbulence effect caused by single-point water inflow, so that the seepage pressure is evenly distributed along the width of the model, improving the uniformity and repeatability of the seepage field.

[0038] In one embodiment, the water distribution component 24 includes a water distributor 241 and multiple water distribution pipes 242 connected to the water distributor 241. The water distributor 241 is connected to the upstream oil tank 22 via an oil pipeline 27. A multi-functional valve 243 is installed on the oil pipeline 27. The multi-functional valve 243 is used to cut off the oil pipeline 27, adjust the flow rate of the oil pipeline 27, or prevent backflow in the oil pipeline 27. The multi-functional valve 243 can collect the flow rate and velocity of the liquid flowing through the oil pipeline 27. By installing the multi-functional valve 243 on the water distributor 241, the flow rate and velocity of the liquid flowing through the water distributor 241 can be collected and adjusted in real time. It is electrically connected to the information acquisition and processing module 50, which can realize precise control and closed-loop feedback regulation of seepage flow rate, thereby improving the accuracy of seepage gradient setting. It can also simultaneously acquire key parameters such as seepage pressure, flow rate, and flow rate, providing reliable data support for permeability coefficient calculation, erosion rate analysis, and seepage-deformation coupling mechanism research, thereby enhancing the quantitative analysis capability of model tests and the accuracy of engineering simulation.

[0039] In one embodiment, the upstream oil tank 22 is connected to the oil storage tank 21 via an overflow pipe 25, which is used to control the liquid level in the upstream oil tank 22 to be maintained at a preset height.

[0040] By setting an overflow pipe 25 between the upstream oil tank 22 and the oil storage tank 21, the liquid in the upstream oil tank 22 can flow back to the oil storage tank 21 through the overflow pipe 25 when the preset liquid level is reached. This stabilizes the liquid level in the upstream oil tank 22 at a constant height, thereby ensuring that the seepage entering the model box 14 has a stable head boundary condition, avoiding changes in the seepage pressure gradient due to liquid level fluctuations, and improving the stability and repeatability of the seepage field.

[0041] In one embodiment, a liquid level sensor 26 is installed in both the upstream oil tank 22 and the downstream oil collection tank 23, and both liquid level sensors 26 are electrically connected to the information acquisition and processing module 50.

[0042] By installing level sensors 26 in the upstream oil tank 22 and the downstream oil collection tank 23 respectively, and electrically connecting them to the information acquisition and processing module 50, the changes in upstream and downstream liquid levels over time can be acquired in real time. The real-time seepage flow rate and average flow velocity can be calculated by combining the rate of change of liquid level with the known cross-sectional area of ​​the tank. This enables dynamic monitoring and continuous calculation of the seepage process, avoiding the errors caused by traditional methods that rely on timed sampling or intermittent measurement, thereby improving the timeliness and accuracy of seepage parameter acquisition.

[0043] In one embodiment, there are multiple light source structures 13. A light-transmitting hole 111 is provided on the base 11 corresponding to the bottom observation area of ​​the model box 14. At least one light source structure 13 is disposed at the bottom of the model box 14 and corresponding to the light-transmitting hole 111, while the remaining light source structures 13 are disposed on the gantry 12 and located above the model box 14. Each light source structure 13 includes a driving component 131 and a light source component 132 connected to the driving component 131. The driving component 131 drives the light source component 132 to move relative to the model box 14. Furthermore, the refractive indices of the solid particles and the liquid pore fluid in the transparent soil model can be matched to a high degree of consistency. Existing transparent soil experimental models typically have only one light source. By scanning a single cross-section, it is difficult to capture the three-dimensional evolution effect. Furthermore, a single light source is easily affected by soil particles, such as obstruction, absorption, and scattering, which leads to laser light energy attenuation, low imaging quality, difficulty in identification, and poor visualization.

[0044] Therefore, this application sets up a model box 14 on the base 11, and opens a light-transmitting hole 111 on the base 11 at the position corresponding to the model box 14, adjusting the refractive index of the solid particles and the liquid pore fluid in the model box 14 to be highly consistent. When light passes through the solid-liquid interface, due to the extremely small difference in refractive index, the refraction and scattering effects of light are significantly suppressed, making the porous medium appear optically transparent on a macroscopic scale. A portion of the light source structure 13 is set on the gantry 12 located outside the base 11, and another portion of the light source structure 13 is set at the bottom position corresponding to the light-transmitting hole 111. Light is irradiated onto the model box 14 from different directions through multiple light source structures 13. The brightness distribution of the superimposed composite light field tends to be uniform in the vertical direction, which cancels the attenuation of light energy caused by soil particles blocking it and compensates for the blind zone of a single light source, providing a physical basis for laser to penetrate the soil and illuminate the interior.

[0045] As can be seen, this application, through the use of a transparent soil model 141 with refractive index matching and multiple light source structures 13, reduces light refraction and scattering, thereby lowering light loss. Furthermore, the multiple light source structures 13 compensate for each other, ensuring that when light from a certain direction is blocked by a particle, light from other angles can illuminate the shaded area of ​​that particle. This spatially complementary lighting mechanism effectively fills the shadow gaps between particles, effectively reduces blind spots, and improves the uniformity of illumination within the transparent soil, thus improving the imaging quality during subsequent simulation experiments and reducing the difficulty of image recognition.

[0046] In one embodiment, a bottom slide rail 60 is provided at the bottom of the model box 14. The drive assembly 131 includes a slider 1311 and a telescopic bracket 1312. The slider 1311 of the light source structure 13 located at the top of the model box 14 is slidably connected to the crossbeam 121. The slider 1311 of the light source structure 13 located at the bottom of the model box 14 is slidably connected to the bottom slide rail 60. The slider 1311 is connected to the light source assembly 132 through the telescopic bracket 1312. The telescopic bracket 1312 is used to drive the light source assembly 132 to move toward or away from the model box 14.

[0047] By incorporating a sliding member 1311 in the drive assembly 131 that can slide along the crossbeam 121 or the bottom slide rail 60, and by setting a telescopic bracket 1312 between the sliding member 1311 and the light source assembly 132, the light source assembly 132 simultaneously possesses planar position adjustment capability and height direction adjustment capability. The sliding of the sliding member 1311 allows the light source assembly 132 to be positioned at different lateral positions above or below the model box 14, thereby changing the incident position of the light and expanding the coverage area of ​​the upper illumination. The telescopic bracket 1312 allows the distance between the light source assembly 132 and the model box 14 to be adjustable, facilitating fine adjustment of the illumination intensity and incident angle according to the thickness of the transparent soil model 141, the location of the experimental area, and imaging requirements. Through this structure, the upper light source can flexibly adapt to different scanning areas and experimental conditions during the experiment, avoiding uneven local illumination or imaging blind spots caused by a fixed light source position, thereby improving the uniformity and controllability of the light field distribution inside the transparent soil model 141, and further enhancing the clarity and stability of the three-dimensional imaging effect.

[0048] In one embodiment, the drive assembly 131 connected to the crossbeam 121 further includes a universal joint 133, which is disposed between the telescopic bracket 1312 and the light source assembly 132 and is used to drive the light source assembly 132 to rotate relative to the model box 14.

[0049] The gimbal 133 allows the first light source assembly 132 to rotate with multiple degrees of freedom relative to the model box 14, thereby changing the direction and angle of incidence of the light to adapt to the imaging needs of different heights, depths, and lateral areas within the model box 14. By adjusting the orientation of the light source, the light can avoid locally obstructed areas and provide directional supplementary lighting for areas prone to shadows or reflection interference, reducing dark areas and high-contrast phenomena caused by a fixed incident direction. Thus, without increasing the number of light sources, the illumination flexibility and coverage of a single upper light source are improved, which is beneficial for further balancing the illumination distribution inside the transparent soil model 141 and improving image quality and recognition stability during 3D scanning and imaging.

[0050] In one embodiment, the model box 14 is made of transparent material. The model box 14 is divided sequentially into an upstream buffer zone 145, a middle test filling zone, and a downstream monitoring and collection zone 147 along the internal fluid flow direction. The upstream buffer zone 145 is equipped with an inlet buffer layer 1451 and a porous flow equalization plate 1452 to eliminate turbulence at the fluid inlet and disperse pore water pressure. The bottom of the downstream monitoring and collection zone 147 extends downwards to form a filter tank 1473, which contains a filter screen 1472. The middle test filling zone... A transparent soil model 141 is set up in the construction area. A guide plate 148 is installed at the toe of the transparent soil model 141. The discharge end of the guide plate 148 extends into the filter screen 1472 to receive and guide the transparent soil particles lost due to erosion. A hook 122 is fixed on the crossbeam 121. A tension sensor 123 is suspended from the lower end of the hook 122. The filter screen 1472 is connected to the tension sensor 123 via a suspension rope 124. The tension sensor 123 is electrically connected to the information acquisition and processing module 50 for real-time weighing of the collected lost particles. Specifically, the liquid inlet buffer layer 1451 is filled with large-diameter glass beads or gravel.

[0051] On the one hand, by setting an inlet buffer layer 1451 filled with large-diameter glass beads or gravel in the upstream buffer zone 145, and in conjunction with a porous flow equalization plate 1452, the flow velocity can be graded and uniformly distributed before the fluid enters the transparent soil model 141, thereby weakening the local high-speed jet and turbulence effect at the inlet, reducing the impact of instantaneous hydraulic impact on the structural stability of the test filling area, and achieving uniform transmission of pore water pressure, thus improving the stability and repeatability of the seepage field.

[0052] On the other hand, a fine particle collection device 1471, including a detachable filter screen 1472 and a filter tank 1473, is installed in the downstream monitoring and collection area 147. Through the cooperation of the filter screen 1472 and the guide plate 148, while ensuring continuous discharge of seepage, the guide plate 148 introduces fine particles migrating with the water flow into the filter screen 1472. The filter screen 1472 physically intercepts and grades the fine particles, which is beneficial for quantitative statistical and comparative analysis of particle loss behavior of the transparent soil model 141 under different hydraulic gradient conditions. By centrally collecting and subsequently weighing or analyzing the lost particles, a quantitative assessment of the degree of erosion and the evolution of the internal structure can be achieved, improving the analytical depth and data integrity of the experimental results. The tensile sensor 123 is used to detect the weight of the lost particles in the filter screen in real time, facilitating more accurate data for subsequent soil loss data analysis.

[0053] Specifically, the model box 14 is made of high-transmittance, high-strength acrylic or borosilicate glass, and its refractive index matches that of the pore fluid and transparent soil model 141 particles used, so as to minimize the interference of light refraction and reflection and ensure the clarity of the internal flow field and deformation field observation.

[0054] In one embodiment, the top of the model box 14 is open. The transparent soil experimental platform 10 also includes an upper cover plate 70, which is adapted to the opening. A sealing buckle 71 is provided on the outer periphery of the upper cover plate 70. The sealing buckle 71 is used to cooperate with the edge of the opening to seal the model box 14. A vacuum saturation interface 72 is also provided on the upper cover plate 70. The vacuum saturation interface 72 is used to communicate with an external vacuum pumping device to evacuate the model box 14.

[0055] By setting the top of the model box 14 as an open structure and equipping it with a matching top cover plate 70, the transparent soil model 141 is made more convenient to fill and maintain. At the same time, by setting a sealing buckle 71 on the outer periphery of the top cover plate 70 to form a tight fit with the edge of the opening, a reliable sealed space can be constructed during the test to prevent leakage of seepage liquid and air from entering and affecting the stability of seepage boundary conditions. Furthermore, a vacuum saturation interface 72 is set on the top cover plate 70 and connected to an external vacuum pumping device, which can be used to evacuate the inside of the model box 14 before the test, effectively removing residual gas in the pores of the transparent soil, allowing the pore fluid to fully fill the gaps between particles, improving the saturation and refractive index matching effect of the transparent soil medium, reducing the interference of air bubbles on optical imaging and seepage continuity, thereby ensuring the clarity of the internal structure visualization and the accuracy of seepage parameter measurement, and enhancing the stability and repeatability of the test results.

[0056] In one embodiment, a detachable mold 80 is also provided inside the model box 14. The mold is a hollow triangular or trapezoidal structure, and the shape of the mold is adapted to the shape of the transparent soil model 141.

[0057] By setting a detachable mold 80 inside the model box 14, and the mold being a hollow triangular or trapezoidal structure adapted to the shape of the transparent soil model 141, the transparent soil model 141 can form a predetermined slope or dam geometry during the filling process. This ensures the controllability and consistency of the model's external dimensions and slope angle parameters, avoiding the influence of geometric errors caused by manual stacking on the test results. At the same time, the mold is a hollow structure, which can be extracted as a whole or dismantled in parts after filling is completed without damaging the formed transparent soil structure. This helps maintain the stability of the particle arrangement and initial stress state inside the model, thereby improving the model forming quality and the consistency of repeated tests, and enhancing the applicability and engineering simulation accuracy of the device in conducting seepage erosion and stability tests under different slope ratios and structural forms.

[0058] In one embodiment, the model box 14 is arranged in the shape of a cuboid, and the light-transmitting hole 111 is a rectangular through hole, and its extension direction is the same as the long side direction of the model box 14.

[0059] The light-transmitting hole 111 is a rectangular through hole extending along the long side of the model box 14, so that the bottom light forms a continuous transmission window that extends along the length direction below the model box 14, which is beneficial for the bottom light source to form a stable and continuous linear or planar illumination area inside the model box 14 during the movement.

[0060] In one embodiment, the transparent soil experimental apparatus 100 further includes a positioning plate 90, which is disposed around the outer periphery of the model box 14 and forms a limiting groove 91. The outer wall of the model box 14 abuts against the side wall of the limiting groove 91 to form a limiting position. A plurality of positioning elements 92 are provided on the positioning plate 90 at intervals. An adapter is provided on the base 11 corresponding to each positioning element 92. The positioning element 92 is used to cooperate with the corresponding adapter to fix the positioning plate 90 on the base 11.

[0061] By spaced-apart positioning elements 92 on the positioning plate 90 and matching fittings that mate with the positioning elements 92 on the base 11, the positioning plate 90 can be stably fixed on the base 11. Simultaneously, the sidewall of the limiting groove 91 abuts against the outer wall of the model box 14, thus reliably limiting the installation position and orientation of the model box 14 on the base 11, preventing translational or rotational displacement of the model box 14 during assembly or experimentation. This structure helps ensure a stable and consistent relative positional relationship between the model box 14 and each light source structure 13, improving the repeatability of the arrangement under multiple experiments or different scanning conditions, thereby enhancing the comparability of imaging results and the reliability of experimental data.

[0062] Specifically, the positioning element 92 can be a screw or bolt set on the positioning plate 90, and the adapter can be a screw hole or nut set on the base 11. The positioning element 92 and the adapter can also be a structure that is mutually engaged.

[0063] In one embodiment, both the base 11 and the gantry 12 are coated with matte paint.

[0064] By applying matte paint to the surfaces of the base 11 and the gantry 12, specular and stray reflections of light on the structural surfaces can be effectively reduced, weakening the interference of ambient reflected light on the imaging process of the transparent soil model 141. This helps to improve the utilization rate of effective illumination light within the model box 14, improve image background contrast, avoid imaging noise caused by reflected glare, and thus further enhance imaging clarity and image recognition stability.

[0065] In one specific embodiment, a transparent soil simulation experiment is conducted using the aforementioned transparent soil testing apparatus 100 to simulate the development process of soil piping failure under a combined state of vertical load and horizontal seepage. The transparent soil testing method includes the following steps: S100: Prepare a transparent soil model 141 inside the model box 14; Based on the density and slope angle designed for the experiment, a suitable detachable mold 80 was selected and placed inside the model box. Transparent soil particles and refractive index matching liquid were mixed in a predetermined ratio and filled into the model box using a layered compaction method until the predetermined height was reached. After compaction, the sample preparation support was carefully and vertically removed from the model box to form a complete slope or dam model.

[0066] S200: Secure the upper cover plate 70 to the model box 14 with the sealing buckle 71, seal the liquid inlet pipe 221, liquid outlet pipe 231 and vacuum saturation interface 72, check the sealing performance of the model box 14, and after the sealing performance is qualified, connect the external vacuum pump to the vacuum saturation interface 72, and vacuum saturate for 12 hours at negative one atmosphere to reduce air bubbles in the transparent soil model and obtain a better visual effect.

[0067] S300: The vertical pusher 31 is started by controlling the information acquisition and processing module 50 to apply vertical load at a preset loading rate or pressure and maintain stability. The water distributor 241 is adjusted by the multi-functional valve 243 to slowly inject oil into the upstream buffer zone 145 of the model box 14, so that the liquid level in the upstream buffer zone 145 is stabilized at a predetermined height. When the pore fluid reaches the outlet pipe 231 of the downstream monitoring and collection area 147 through the transparent soil model 141, the liquid level in the downstream monitoring and collection area 147 can be controlled by adjusting the throttle valve 232 on the outlet pipe 231, thereby forming a stable and controllable horizontal seepage field in the soil. It should be noted that the throttle valve 232 on the outlet pipe 231 and the multi-functional valve 243 on the oil pipeline 27 have the same function, both of which can realize the functions of cut-off, check, and flow control.

[0068] S400: The transparent soil model 141 is illuminated by the light source structure 13, and the camera module 40 continuously captures and records the particle movement and fluid flow inside the soil using PIV (particle image velocimetry) and PLIF (planar laser-induced fluorescence) technologies, collecting image data of the transparent soil model 141 during the seepage process. At the same time, the information acquisition and processing module 50 collects data such as seepage pressure, seepage velocity, seepage flow rate, vertical load value, and vertical displacement obtained from each liquid level sensor 26, pressure sensor, displacement sensor 33, and multi-functional valve 243. Meanwhile, the fine particles intercepted at the filter screen 1472 are collected and weighed to obtain particle erosion quality data. S500: The information acquisition and processing module 50 receives and stores all data collected in step S400 in real time. Image processing software is used to analyze particle motion trajectories, flow velocity fields, and erosion processes; the data analysis program integrates various parameters to study the development mechanism of piping and slope failure.

[0069] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A transparent soil experimental apparatus, characterized in that, include: A transparent soil experimental platform includes a base, a gantry frame, and a light source structure. A model box is set on the base, and a transparent soil model is set inside the model box. A crossbeam is set above the model box on the gantry frame, and the light source structure is set in relation to the model box and is used to illuminate the transparent soil model. A seepage pressurization module, which is connected to the model box and is used to provide a horizontal seepage field for the model box; A vertical pressurization module is installed on the gantry and is used to apply a vertical load to the transparent soil model inside the model box; A camera module is disposed on the side of the model box and is used to capture images of the transparent soil model; The information acquisition and processing module, the seepage pressurization module, the vertical pressurization module and the camera module are all electrically connected to the information acquisition and processing module.

2. The transparent soil experimental apparatus as described in claim 1, characterized in that, A rigid loading block is provided on the top of the transparent soil model. The vertical pressurization module includes a vertical pusher, which is installed on the crossbeam. The output end of the vertical pusher pushes the rigid loading block down through a telescopic force transmission rod to apply a vertical load to the transparent soil model. A pressure sensor is provided on the telescopic force transmission rod. Both the pressure sensor and the vertical pusher are electrically connected to the information acquisition and processing module.

3. The transparent soil experimental apparatus as described in claim 2, characterized in that, A displacement sensor is provided on the vertical pusher or the crossbeam. The displacement sensor is used to detect the vertical settlement of the transparent soil model, and the displacement sensor is electrically connected to the information acquisition and processing module.

4. The transparent soil experimental apparatus as described in claim 1, characterized in that, The model box includes an inlet side and an outlet side. The seepage pressurization module includes an oil storage tank, an upstream oil transfer tank, a downstream oil collection tank, and a water distribution component. The upstream oil transfer tank is connected to the oil storage tank through an inlet pipe, and an oil pump is installed on the inlet pipe. The upstream oil transfer tank is connected to the water distribution component, which is used to divide the liquid in the upstream oil transfer tank into multiple branches and connect them to the inlet side respectively. The outlet side is connected to the downstream oil collection tank.

5. The transparent soil experimental apparatus as described in claim 4, characterized in that, The water distribution assembly includes a water distributor and multiple water distribution pipes connected to the water distributor. The water distributor is connected to the upstream oil tank via an oil pipeline. A multi-functional valve is installed on the oil pipeline. The multi-functional valve is used to cut off the oil pipeline, adjust the flow rate of the oil pipeline, or prevent backflow in the oil pipeline. The multi-functional valve can collect the flow rate and velocity of the liquid flowing through the oil pipeline. And / or, the upstream oil tank is connected to the oil storage tank via an overflow pipe, and the overflow pipe is used to control the liquid level in the upstream oil tank to be maintained at a preset height.

6. The transparent soil experimental apparatus as described in claim 4, characterized in that, Both the upstream oil tank and the downstream oil collection tank are equipped with level sensors, and both level sensors are electrically connected to the information acquisition and processing module.

7. The transparent soil experimental apparatus as described in any one of claims 1 to 6, characterized in that, The number of light source structures is multiple. A light-transmitting hole is provided on the base corresponding to the bottom observation area of ​​the model box. At least one of the light source structures is set at the bottom of the model box and is set corresponding to the light-transmitting hole. The remaining light source structures are set on the gantry frame and located above the model box. The light source structure includes a driving component and a light source component connected to the driving component. The driving component is used to drive the light source component to move relative to the model box.

8. The transparent soil experimental apparatus as described in claim 7, characterized in that, The bottom of the model box is provided with a bottom slide rail. The driving component includes a slider and a telescopic bracket. The slider of the light source structure located at the top of the model box is slidably connected to the crossbeam. The slider of the light source structure located at the bottom of the model box is slidably connected to the bottom slide rail. The slider is connected to the light source component through the telescopic bracket. The telescopic bracket is used to drive the light source component to move towards or away from the model box.

9. The transparent soil experimental apparatus as described in any one of claims 1 to 6, characterized in that, The model box is made of transparent material and is divided into an upstream buffer zone, a middle test filling zone, and a downstream monitoring and collection zone along the internal fluid flow direction. The upstream buffer zone is equipped with an inlet buffer layer and a porous flow equalization plate to eliminate turbulence at the fluid inlet and disperse pore water pressure. A filter tank extends downwards from the bottom of the downstream monitoring and collection zone, containing a filter screen. The transparent soil model is located in the middle test filling zone, and a guide plate is installed at the toe of the transparent soil model. The discharge end of the guide plate extends into the filter screen to collect and guide the eroded transparent soil particles. A hook is fixed to the crossbeam, and a tension sensor is suspended from the lower end of the hook. The filter screen is connected to the tension sensor via a rope. The tension sensor is electrically connected to the information acquisition and processing module for real-time weighing of the collected lost particles.

10. The transparent soil experimental apparatus as described in any one of claims 1 to 6, characterized in that, The top of the model box is open. The transparent soil experimental platform also includes a top cover plate, which is adapted to the opening. The outer periphery of the top cover plate is provided with a sealing buckle, which is used to cooperate with the edge of the opening to seal the model box. The top cover plate is also provided with a vacuum saturation interface, which is used to connect with an external vacuum pump to evacuate the model box.

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