An experimental device for analyzing stability of rock-soil mass under different confining pressures under rainfall conditions

Abstract

The utility model relates to the technical field of rock and soil experiment simulation device, concretely is a kind of stability analysis experimental device of rock and soil mass under rainfall condition under different confining pressure, including supporting device, water supply device, rainfall device, confining pressure implementation device, drainage device and pressure monitoring device;Supporting device includes test table, base, baffle and telescopic rod;Whole test device is placed on test table;Baffle is installed on base, is fixed by telescopic rod;Scale bucket is connected with rain water supply tank by water inlet pipe, and the water pump in rain water supply tank is connected the base inlet hole of base by water outlet pipe, and water flow is transported to rain head by water inlet pipe channel, and simulation rainfall is formed by air mist spray head, and rainfall is controlled by scale bucket measurement. In the stability analysis experimental device of rock and soil mass under rainfall condition under different confining pressure, the precise simulation of rainfall and confining pressure coupling condition is realized, and real engineering scene is reproduced.

Description

Technical Field

[0001] This utility model relates to the technical field of rock and soil experimental simulation devices, specifically, to an experimental device for analyzing the stability of rock and soil under different confining pressures under rainfall conditions. Background Technology

[0002] Against the backdrop of my country's rapid economic development and continuous infrastructure construction, the number and scale of slope engineering projects in highways, railways, water conservancy, mining and other fields are constantly expanding. Their stability directly determines the safe operation of the project, the effectiveness of ecological and environmental protection, and the safety of people's lives and property, and has become one of the core issues of key concern in the field of geotechnical engineering. Slope stability is influenced by a combination of factors, including geological structure, hydrological conditions, and external loads, with rainfall being a key natural factor triggering slope disasters. Southern my country, due to its climate characteristics, experiences abundant and concentrated annual rainfall, with frequent short-duration heavy rainfall events, which have a more significant impact on slope soil and rock masses. During rainfall, rainwater continuously infiltrates the soil and rock mass, causing a sharp increase in pore water pressure and a significant decrease in effective stress, thus significantly weakening the shear strength of the soil and rock mass. Simultaneously, rainwater erosion damages the surface structure of the soil and rock mass, exacerbating internal fissure development. This dual effect greatly increases the risk of landslides and collapses. Statistics show that over 70% of slope disasters in my country are directly related to rainfall. Each year, slope instability accidents induced by rainfall not only cause huge economic losses but also pose a serious threat to the lives of surrounding residents and the ecological environment. Besides rainfall, confining pressure, as a crucial mechanical factor influencing the mechanical properties of slope soil and rock, plays an equally significant role in regulating slope stability. In slope engineering, confining pressure increases with the burial depth of the soil and rock mass, and is subject to dynamic changes due to external factors such as groundwater level fluctuations, seismic activity, and engineering excavation. When the groundwater level rises, the transmission of pore water pressure leads to a decrease in effective confining pressure, making the soil and rock mass prone to softening and deformation. Under seismic loading, instantaneous dynamic loads can disrupt the original confining pressure equilibrium, causing stress redistribution in the soil and rock mass and increasing the risk of slippage. During engineering excavation, the lateral constraint of the slope weakens, and sudden changes in confining pressure may directly induce local instability. Therefore, accurately understanding the deformation patterns, strength attenuation characteristics, and failure mechanisms of soil and rock mass under different confining pressure conditions is the core technical basis for slope engineering design optimization and disaster early warning and prevention. However, in actual engineering scenarios, rainfall and confining pressure do not act independently on slopes; their coupling effect makes the slope stability evolution process more complex. The increased water content of soil and rock caused by rainfall alters their physical and mechanical parameters, making the regulatory effect of confining pressure on soil and rock deformation nonlinear. Simultaneously, changes in confining pressure affect the pore structure and seepage channels of the soil and rock, thereby altering the infiltration rate and distribution pattern of rainwater, forming a complex feedback loop of "rainfall-seepage-confining pressure-deformation." For example, after rainfall, the soil and rock are in a high water content state. At this time, even a small change in confining pressure may trigger a transition from elastic deformation to plastic flow, leading to localized shear failure. If this is not monitored and controlled in time, it can easily develop into overall slope instability. Currently, research methods for slope stability mainly include field monitoring, numerical simulation, and indoor experiments. While field monitoring can obtain slope response data under real-world conditions, it is limited by topographical conditions, climate interference, and long monitoring cycles, making it difficult to systematically analyze the intrinsic mechanisms under the coupled effects of rainfall and confining pressure. Numerical simulation relies on the accuracy of parameter selection and cannot fully reproduce the complex physical and mechanical behavior of soil and rock masses. Existing indoor experimental devices have significant limitations: most devices can only simulate rainfall or confining pressure conditions individually, failing to achieve precise control of their synergistic effects; some confining pressure application devices use rigid loading methods, making it difficult to ensure the uniformity of pressure transmission and easily leading to localized stress concentration in the soil and rock mass; rainfall simulation devices can mostly only adjust the amount of rainfall, failing to simulate key parameters such as rainfall intensity and raindrop kinetic energy, resulting in significant differences from actual rainfall scenarios. Utility Model Content

[0003] The purpose of this invention is to provide an experimental device for analyzing the stability of soil and rock under different confining pressures during rainfall, in order to solve the problems mentioned in the background art. Although field monitoring can obtain slope response data under real environment, it is limited by topographic conditions, climate interference, long monitoring cycle, etc., making it difficult to systematically analyze the internal mechanism under the coupling effect of rainfall and confining pressure; numerical simulation depends on the accuracy of parameter selection and cannot fully reproduce the complex physical and mechanical behavior of soil and rock.

[0004] To achieve the above objectives, this utility model provides an experimental device for analyzing the stability of soil and rock under different confining pressures during rainfall, including a support device, a water supply device, a rainfall device, a confining pressure implementation device, a drainage device, and a pressure monitoring device. The support device includes a test bench, a base, a baffle, and a telescopic rod; the entire test device is placed on the test bench; the baffle is installed on the base and fixed by the telescopic rod. The rainfall device includes a rainwater supply tank, a graduated cylinder, a water inlet pipe channel, a rain head, and an aerosol nozzle. The graduated cylinder is connected to the rainwater supply tank via the water inlet pipe. The water pump in the rainwater supply tank is connected to the base inlet hole of the base via the water outlet pipe. Water flows through the water inlet pipe channel to the rain head and forms simulated rainfall through the aerosol nozzle. The rainfall amount is measured and controlled by the graduated cylinder. The confining pressure implementation device is located inside the baffle and includes an airbag chamber, a waterbag chamber, an airbag, a waterbag, a thin plastic plate, an airbag inlet, an airbag inlet pipe, an airbag outlet, an airbag outlet, a waterbag outlet, a waterbag outlet, and a waterbag outlet and outlet pipe. The waterbag is placed inside the waterbag chamber, and the airbag is placed inside the airbag chamber. The airbag inlet pipe is connected to an inflation device, and the waterbag outlet is used for water injection. Through the inflation of the airbag and the water filling of the waterbag, uniform confining pressure is transmitted to the rock and soil mass through the thin plastic plate. A water injection chamber is provided at the top of the waterbag chamber, and the airbags are connected by air guide pipes. The drainage device includes a base drainage hole, a seepage storage chamber, a drainage tank inlet, a drainage tank inlet pipe, a drainage tank, a drainage outlet, a high-density filter plate, a drainage pipe, and a drainage bucket. Seepage water enters the seepage storage chamber through the seepage hole in the base, then enters the drainage tank through the base drainage hole and the drainage tank inlet pipe. After being filtered by the high-density filter plate, it is discharged into the drainage bucket through the drainage pipe.

[0005] This setup provides a stable foundation for the entire system through a support device, using the test bench as a load-bearing platform. The base and baffle work together to form the experimental space, and a telescopic rod fixes the baffle to ensure structural stability during the experiment. The rainfall device supplies water quantitatively through a graduated cylinder, pressurizes it through a pump in the rainwater supply tank, and delivers it to the rain head through the outlet and inlet pipes, creating simulated rainfall in conjunction with the mist nozzles. The confining pressure device generates pressure by inflating airbags and filling waterbags, and evenly transmits the pressure to the soil and rock mass through a thin plastic plate. The airbags are pressurized synchronously through air guide pipes, and the water filling chamber at the top of the waterbag chamber ensures even filling of the waterbags. The drainage device collects seepage water from the soil and rock mass through seepage holes, which flows into the drainage tank through the seepage storage chamber, the drainage hole in the base, and the inlet pipe of the drainage tank. After impurities are filtered by a high-density filter plate, the water is discharged into the drainage bucket through the drainage pipe. The pressure monitoring device monitors pressure changes in real time during the experiment. All devices work together to realize the stability experiment of the soil and rock mass under the coupled conditions of rainfall and confining pressure.

[0006] Preferably, the test bench is supported by a test bench support rod, and the base includes a permeable stone base on which permeable stones are provided.

[0007] This setup integrates the test bench support rod with the test bench, and based on the principles of mechanical support, it increases the support points to distribute the load on the test bench, thereby improving the overall support stability. The permeable stone base in the base provides the installation foundation for the permeable stone. Utilizing its porous structure, the permeable stone follows the principles of seepage mechanics, allowing water to seep smoothly through the soil and rock while blocking soil and rock particles to prevent blockage of the seepage channels.

[0008] Preferably, the telescopic rod comprises a sleeve and a telescopic rod, which are locked together by a support rod fixing bolt. A support rod base is installed at the bottom of the telescopic rod, and a support rod washer is installed at the top of the telescopic rod.

[0009] This design features a sliding fit structure between the telescopic rod and its sleeve. The position of the telescopic rod within the sleeve is adjusted according to the required baffle height for the experiment. The sleeve and telescopic rod are then mechanically locked together using the support rod fixing bolts, thus achieving length adjustment of the telescopic rod. The support rod base increases the contact area with the contact surface, improving the stability of the bottom of the telescopic rod based on the principle of friction. The support rod gasket further increases the contact area between the telescopic rod and the baffle, dispersing pressure and preventing excessive localized pressure from damaging the baffle.

[0010] Preferably, the pressure monitoring device includes a pressure sensor, a pressure sensor gasket, a pressure sensor groove, a pressure sensor wiring tube, and a pressure sensor instrument; the pressure sensor is disposed in the pressure sensor groove and fixed by the pressure sensor gasket, and the pressure sensor data transmission line is connected to the pressure sensor instrument via the pressure sensor wiring tube.

[0011] This pressure sensor setup utilizes the principle of mechanical sensing to convert the pressure on the soil or rock mass into an electrical signal. The pressure sensor recess provides installation and positioning space, while the pressure sensor gasket acts as a buffer, ensuring tight contact between the pressure sensor and the soil or related components, thus improving pressure detection accuracy. The pressure sensor data transmission line transmits the electrical signal generated by the sensor to the pressure sensor instrument via the pressure sensor wiring tube. The pressure sensor instrument processes and displays the electrical signal, enabling real-time monitoring of pressure data.

[0012] Preferably, in the confining pressure implementation device, the water bladder needs to be drained of internal moisture before being laid, and the water bladder drain outlet is closed after laying, and water is injected until overflowing; after the air bladder is laid, the air bladder exhaust outlet is closed, and air is slowly inflated through the inflation device to adjust the confining pressure.

[0013] Before laying the water-filled bladders, all internal moisture is drained to eliminate any interference from existing moisture on the confining pressure. After laying, the drain outlet of the water-filled bladders is closed, and water is injected until overflowing. Based on the principle of hydrostatic pressure, this ensures uniform and stable pressure within the water-filled bladders, providing initial uniform pressure to the soil and rock mass. After laying the air-filled bladders, the exhaust outlet is closed, and air is slowly inflated using an inflation device. Utilizing the compressibility and fluidity of gas, the pressure within the air-filled bladders gradually increases, and this pressure is then transmitted to the soil and rock mass through a thin plastic plate, achieving precise adjustment of the confining pressure.

[0014] Preferably, in the rainfall device, the rain head and the mist nozzle are combined and arranged so that different intensities of rainfall can be simulated by adjusting the water pump power and the number of nozzles turned on.

[0015] This setup combines rain nozzles and mist nozzles. The rain nozzles simulate large-volume rainfall, while the mist nozzles generate fine droplets to simulate different rainfall patterns, such as drizzle. By adjusting the water pump power, the water output pressure and flow rate are changed, thereby adjusting the water output intensity of the rain nozzles and mist nozzles. By controlling the number of nozzles in operation, the rainfall coverage and total rainfall are changed, and the combination of both allows for the simulation of rainfall of varying intensities.

[0016] Preferably, in the support device, the air bladder and water bladder of the confining pressure implementing device are both made of flexible materials and are tightly fitted with the thin plastic plate to ensure uniform pressure transmission.

[0017] The airbags and waterbags in this setup are made of flexible materials. Based on the deformation characteristics of flexible materials, they can fit tightly against the thin plastic sheet under pressure, avoiding gaps and ensuring that pressure is transmitted evenly and comprehensively to the thin plastic sheet. The thin plastic sheet has a certain degree of rigidity, which further disperses the pressure transmitted by the airbags and waterbags before it is evenly distributed to the soil and rock mass, preventing localized pressure concentration.

[0018] Preferably, the base of the drainage device is equipped with a water valve to control the drainage rate of the seepage storage chamber, the rainwater supply tank of the rain device is equipped with a water outlet to control the water supply flow, the water inlet pipe channel is made of corrosion-resistant pipe material and is sealed to the water inlet hole of the base, and one end of the rainwater supply tank is equipped with a water inlet.

[0019] In this drainage system, the water valve adjusts the flow rate of seepage water at the outlet of the seepage storage chamber by changing the valve opening, based on fluid mechanics principles, thereby controlling the drainage rate and simulating the seepage environment of soil and rock under different drainage conditions. In the rainmaking device, the outlet of the rainwater supply tank controls the water flow rate by adjusting the opening, ensuring a stable water supply. The inlet pipe uses corrosion-resistant materials to prevent corrosion from water or impurities during long-term use, extending its service life. The inlet pipe is sealed to the base's inlet hole, preventing leakage and avoiding changes in rainfall parameters due to leakage. The inlet of the rainwater supply tank is used to replenish the water source, ensuring a continuous water supply to the rainmaking device.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows: In this experimental setup for analyzing the stability of soil and rock masses under different confining pressures during rainfall, accurate simulation of the coupled working conditions of rainfall and confining pressure is achieved, thus reproducing real engineering scenarios.

[0021] The device employs a combination of rain shower heads and mist nozzles, along with an adjustable-power water pump and a graduated cylinder for measuring water volume. This allows for precise control of rainfall volume via the graduated cylinder, and by adjusting the water pump power and the number of nozzles activated, it can simulate rainfall scenarios of varying intensities and patterns, covering a wide range of conditions from daily to extreme rainfall, closely mirroring the actual rainfall environment faced by slopes. Furthermore, the water inlet pipe utilizes corrosion-resistant materials and is sealed to the base's water inlet hole, preventing errors in rainfall parameters caused by leakage and further enhancing the accuracy of rainfall simulation. The confining pressure implementation device innovatively adopts a combined structure of "airbag + waterbag + thin plastic plate". Multiple airbags are simultaneously inflated via air delivery pipes, while the waterbags are uniformly filled to overflowing state via an injection chamber. Together, these two components work to evenly transfer pressure to the surface of the soil and rock mass through the thin plastic plate, avoiding the localized stress concentration problems caused by traditional rigid loading methods. Furthermore, by controlling the inflation rate of the airbags and the water volume of the waterbags, the confining pressure can be continuously adjusted from low to high, accurately simulating the confining pressure environment of slope soil and rock masses under different burial depths and external loads, meeting experimental requirements from conventional to extreme confining pressures. The device, through the coordinated control of the rainfall device and the confining pressure implementation device, can simulate the coupled process of "rainfall infiltration - change in soil moisture content - dynamic adjustment of confining pressure" in real time. It accurately reproduces the feedback loop of "rainfall causing soil softening - change in confining pressure exacerbating deformation" in actual engineering, providing a real experimental scenario to support the study of the strength attenuation law and deformation evolution mechanism of soil under the coupled action of rainfall and confining pressure. Ensuring the reliability and integrity of experimental data to support accurate analysis. The pressure monitoring device, by placing a pressure sensor within a pressure sensor groove and securing it with a pressure sensor pad, can collect real-time stress change data of soil and rock under rainfall and confining pressure. The pressure sensor data transmission line is connected to the pressure sensor instrument via a pressure sensor wiring conduit, avoiding data interference caused by cluttered wiring and ensuring stable and accurate pressure data transmission. By combining confining pressure parameters and rainfall parameters, a complete data chain of "rainfall-confining pressure-stress-deformation" can be formed, providing multi-dimensional data support for analyzing the stability of soil and rock masses. The drainage system, through a seepage channel consisting of seepage holes, a seepage storage chamber, and drainage holes in the base, collects seepage water from the soil and rock mass during rainfall. A high-density filter plate filters soil and rock particles from the seepage water, preventing pipe blockage and facilitating subsequent analysis of the seepage water's sand content. A water valve controls the drainage rate of the seepage storage chamber, simulating seepage environments under different drainage conditions and further enriching the dimensions of seepage data. The seepage volume can be measured using the drainage bucket, and combined with rainfall data, key parameters such as the soil and rock mass's infiltration rate and water holding capacity can be calculated, providing direct data for analyzing the impact of rainfall infiltration on the stability of the soil and rock mass. Improve the ease of operation and stability of the device, and reduce the difficulty of experiments. The device adopts a modular design for each component. The support device can quickly adjust the height and fixed position of the baffle by combining the sleeve of the telescopic rod with the telescopic rod and the locking structure of the support rod fixing bolt. In the confining pressure implementation device, the laying and disassembly process of the water bladder and air bladder is simple. Initial preparation can be completed by simply closing the drain outlet / vent outlet, which greatly shortens the installation and debugging time of the experimental device and reduces the operation difficulty for the experimental personnel. In the support device, the test bench is stably supported by the test bench support rod. The support rod base at the bottom of the telescopic rod and the support rod pad at the top further enhance the fixation stability of the baffle and avoid experimental errors or safety hazards caused by device shaking during the experiment. The permeable stone base in the base works in conjunction with the permeable stone to support the soil and rock sample and ensure that the seepage channel is unobstructed. At the same time, it prevents soil and rock particles from clogging the seepage holes, thereby improving the stability and durability of the device operation. Attached Figure Description

[0022] Figure 1 This is one of the overall structural schematic diagrams of this utility model; Figure 2 This is one of the partial structural schematic diagrams of this utility model; Figure 3 This is a second schematic diagram of a partial structure of this utility model; Figure 4 This is a schematic diagram of the structure of the baffle in this utility model; Figure 5 This is a schematic diagram of the confining pressure implementing device in this utility model; Figure 6 This is a schematic diagram of the airbag structure in this utility model; Figure 7 This is a schematic diagram of the water chamber structure in this utility model; Figure 8 This is a schematic diagram of the rainwater supply tank in this utility model; Figure 9 This is a schematic diagram of the structure of the shower head in this utility model; The meanings of the labels in the diagram are as follows: 1. Base; 2. Water inlet pipe channel; 3. Airbag chamber; 4. Seepage hole; 5. Seepage storage chamber; 6. Water valve; 7. Base water inlet hole; 8. Base drain hole; 9. Shower head; 10. Aerosol nozzle; 11. Permeable stone base; 12. Permeable stone; 13. Support rod base; 14. Support rod fixing bolt; 15. Support rod gasket; 16. Baffle; 17. Telescopic rod; 18. Airbag; 19. Pressure sensor gasket; 20. Pressure sensor groove; 21. Airbag air inlet; 22. Airbag air inlet pipe; 23. Airbag exhaust port; 24. Airbag exhaust pipe; 25. Water bag chamber; 26. Water injection chamber; 2 7. Inlet; 28. Inlet pipe; 29. ​​Water pump; 30. High-density filter plate; 31. Pressure sensor wiring pipe; 32. Outlet pipe; 33. Outlet; 34. Rain shower water supply tank; 35. Drainage tank inlet; 36. Drainage tank inlet pipe; 37. Drainage tank; 38. Drain outlet; 39. Drain pipe; 40. Scale barrel; 41. Drainage bucket; 42. Pressure sensor data transmission line; 43. Pressure sensor; 44. Water bladder filling port; 45. Water bladder; 46. Water bladder drain outlet; 47. Water bladder drain pipe; 48. Air guide pipe; 49. Thin plastic sheet; 50. Test bench; 51. Test bench support rod. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] This invention provides an experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures during rainfall, such as... Figures 1-9 As shown, it includes a support device, a water supply device, a rainfall device, a confining pressure implementation device, a drainage device, and a pressure monitoring device; The support device includes a test bench 50, a base 1, a baffle 16, and a telescopic rod 17; the entire test device is placed on the test bench 50; the baffle 16 is installed on the base 1 and fixed by the telescopic rod 17. The rainfall device includes a rainwater supply tank 34, a graduated cylinder 40, a water inlet pipe channel 2, a shower head 9, and an aerosol nozzle 10. The graduated cylinder 40 is connected to the rainwater supply tank 34 through a water inlet pipe 28. The water pump 29 in the rainwater supply tank 34 is connected to the base inlet hole 7 of the base 1 through a water outlet pipe 32. The water flows through the water inlet pipe channel 2 to the shower head 9 and forms simulated rainfall through the aerosol nozzle 10. The rainfall amount is measured and controlled by the graduated cylinder 40. The confining pressure implementation device is located inside the baffle 16 and includes an airbag chamber 3, a waterbag chamber 25, an airbag 18, a waterbag 45, a thin plastic plate 49, an airbag inlet 21, an airbag inlet pipe 22, an airbag outlet 23, an airbag outlet pipe 24, a waterbag inlet 44, a waterbag outlet 46, and a waterbag outlet pipe 47. The waterbag 45 is laid inside the waterbag chamber 25, and the airbag 18 is laid inside the airbag chamber 3. The airbag inlet pipe 22 is connected to an inflation device, and the waterbag inlet 44 is used for water injection. Through the inflation of the airbag 18 and the water filling of the waterbag 45, uniform confining pressure is transmitted to the rock and soil mass through the thin plastic plate 49. A water injection chamber 26 is provided at the top of the waterbag chamber 25, and the airbags 18 are connected by an air guide pipe 48. The drainage device includes a base drainage hole 8, a seepage storage chamber 5, a drainage tank inlet 35, a drainage tank inlet pipe 36, a drainage tank 37, a drainage outlet 38, a high-density filter plate 30, a drainage pipe 39, and a drainage bucket 41. Seepage water enters the seepage storage chamber 5 through the seepage hole 4 of the base 1, and then enters the drainage tank 37 through the base drainage hole 8 and the drainage tank inlet pipe 36. After being filtered by the high-density filter plate 30, it is discharged into the drainage bucket 41 through the drainage pipe 39.

[0025] The experimental device provides a stable foundation for the entire system through a support device, with the test bench 50 serving as a load-bearing platform. The base 1 and the baffle 16 cooperate to form an experimental space, and the telescopic rod 17 fixes the baffle 16 to ensure structural stability during the experiment. The rainfall device supplies water quantitatively through a graduated bucket 40, which is pressurized by a water pump 29 in the rain supply tank 34. The water is then transported to the rain head 9 through the outlet pipe 32 and the inlet pipe channel 2, forming simulated rainfall in conjunction with the mist nozzle 10. The confining pressure implementation device generates pressure by inflating the air bladder 18 and filling the water bladder 45 with water. The pressure is evenly transmitted to the soil and rock mass through the thin plastic plate 49, and the air bladders 18 are pressurized synchronously through the air guide pipe 48. The water injection chamber 26 at the top of the water bladder chamber 25 ensures that the water bladder 45 is evenly filled with water. The drainage device collects seepage water from the soil and rock mass through the seepage hole 4, which enters the drainage tank 37 through the seepage storage chamber 5, the base drainage hole 8, and the drainage tank inlet pipe 36. After the high-density filter plate 30 filters impurities, the water is discharged into the drainage bucket 41 through the drainage pipe 39. The pressure monitoring device monitors the pressure changes in real time during the experiment. All devices work together to realize the stability experiment of the soil and rock mass under the coupled conditions of rainfall and confining pressure. This system simulates the coupled conditions of rainfall and confining pressure, overcoming the limitations of single-factor simulations and more realistically reproducing the environment of soil and rock masses in actual engineering projects. The clearly defined roles and coordinated operation of each component ensure the orderly conduct of the experiment, enabling the acquisition of stability data for soil and rock masses under different rainfall and confining pressure conditions, providing comprehensive experimental support for slope stability research. Furthermore, the overall structural design is rational, ensuring experimental stability and reducing experimental errors caused by factors such as device swaying.

[0026] In this embodiment, the test bench 50 is supported by the test bench support rod 51, and the base 1 includes a permeable stone base 11, on which permeable stones 12 are provided.

[0027] The test bench support rod 51 cooperates with the test bench 50. Based on the principle of mechanical support, the overall support stability is improved by increasing the support points to distribute the load-bearing pressure on the test bench 50. The permeable stone base 11 in the base 1 provides an installation foundation for the permeable stone 12. The permeable stone 12 utilizes its porous structure and follows the principle of seepage mechanics to allow water to seep through the soil and rock while blocking soil and rock particles to avoid clogging the seepage channels. The test bench support rod 51 significantly enhances the load-bearing capacity and stability of the test bench 50, preventing deformation of the test bench 50 due to the weight of the experimental device and the soil and rock mass, thus ensuring experimental accuracy. The permeable stone 12 ensures unobstructed seepage channels, allowing seepage water to smoothly enter the subsequent drainage system while preventing the loss of soil and rock particles. This not only ensures the normal operation of the drainage device but also accurately reflects the seepage characteristics of the soil and rock mass, improving the reliability of experimental data.

[0028] Specifically, the telescopic rod 17 consists of a sleeve and a telescopic rod. The sleeve and the telescopic rod are locked together by a support rod fixing bolt 14. A support rod base 13 is installed at the bottom of the telescopic rod 17, and a support rod gasket 15 is installed at the top of the telescopic rod 17.

[0029] The sleeve and telescopic rod of the telescopic rod 17 adopt a sliding fit structure. The position of the telescopic rod within the sleeve is adjusted according to the required height of the baffle 16 for the experiment. Then, the sleeve and telescopic rod are fixed by the mechanical locking action of the support rod fixing bolt 14, thus achieving length adjustment of the telescopic rod 17. The support rod base 13 increases the contact area with the contact surface, improving the bottom stability of the telescopic rod 17 based on the principle of friction. The support rod gasket 15 increases the contact area between the telescopic rod 17 and the baffle 16, dispersing pressure and preventing excessive local pressure from damaging the baffle 16. The telescopic rod 17 has an adjustable length to accommodate experiments at different heights, enhancing the versatility of the apparatus. The locking mechanism of the support rod fixing bolt 14 ensures the stability of the telescopic rod 17 during experiments, preventing displacement of the baffle 16. The support rod base 13 and support rod gasket 15 further improve the stability of the telescopic rod 17, ensuring reliable fixation of the baffle 16 during experiments and providing a stable experimental space.

[0030] Furthermore, the pressure monitoring device includes a pressure sensor, a pressure sensor pad 19, a pressure sensor groove 20, a pressure sensor wiring tube 31, and a pressure sensor 43; the pressure sensor is disposed in the pressure sensor groove 20 and fixed by the pressure sensor pad 19, and the pressure sensor data transmission line 42 is connected to the pressure sensor 43 via the pressure sensor wiring tube 31.

[0031] The pressure sensor, based on the principle of mechanical sensing, converts the pressure on the soil and rock into an electrical signal. The pressure sensor groove 20 provides installation and positioning space for the pressure sensor, while the pressure sensor gasket 19, through its buffering effect, ensures close contact between the pressure sensor and the soil and rock or related components, improving pressure detection accuracy. The pressure sensor data transmission line 42 transmits the electrical signal generated by the sensor to the pressure sensor instrument 43 via the pressure sensor line tube 31. The pressure sensor instrument 43 processes and displays the electrical signal, enabling real-time monitoring of pressure data. The pressure sensor can collect pressure change data of the soil and rock mass in real time and accurately during the experiment, providing key data support for analyzing the stability of the soil and rock mass under different rainfall and confining pressure conditions. The design of the pressure sensor groove 20 and pressure sensor pad 19 improves the pressure detection accuracy and reduces measurement errors. The pressure sensor circuit tube 31 protects the data transmission line from damage or external interference, ensuring stable data transmission. The pressure sensor 43 facilitates real-time reading and recording of pressure data by the experimenter, improving the convenience of experimental operation.

[0032] Furthermore, in the confining pressure implementation device, the water bladder 45 needs to be drained of internal moisture before being laid, and after being laid, the water bladder drain outlet 46 is closed and water is injected until it overflows; after the air bladder 18 is laid, the air bladder exhaust outlet 23 is closed, and the air is slowly inflated through the inflation device to adjust the confining pressure.

[0033] Before laying the water bladder 45, internal moisture is drained to eliminate interference from existing moisture on the confining pressure. After laying, the drain port 46 of the water bladder is closed, and water is injected until overflowing. Based on the principle of hydrostatic pressure, the pressure inside the water bladder 45 is made uniform and stable, providing initial uniform pressure to the soil and rock mass. After laying the air bladder 18, the exhaust port 23 of the air bladder is closed, and it is slowly inflated through the inflation device. Utilizing the compressibility and fluidity of gas, the pressure inside the air bladder 18 gradually increases, and then the pressure is transmitted to the soil and rock mass through the thin plastic plate 49, achieving precise adjustment of the confining pressure. The water bladder 45 is filled with water until it overflows to ensure uniform initial confining pressure, laying the foundation for subsequent confining pressure adjustment. The air bladder 18 is slowly inflated to achieve continuous and precise adjustment of the confining pressure from low to high, meeting the experimental requirements under different confining pressure conditions. This method of applying confining pressure avoids the local stress concentration problem caused by traditional rigid loading methods, making the confining pressure on the soil and rock mass uniform, improving the accuracy of experimental results, and better simulating the confining pressure conditions of soil and rock masses in actual engineering.

[0034] Furthermore, in the rainfall device, the shower head 9 and the mist nozzle 10 are combined and arranged, and different intensities of rainfall can be simulated by adjusting the power of the water pump 29 and the number of nozzles turned on.

[0035] The combination of rain head 9 and mist nozzle 10 allows for the simulation of large-flow rainfall using rain head 9, while mist nozzle 10 generates fine droplets to simulate different rainfall patterns such as drizzle. By adjusting the power of water pump 29, the water output pressure and flow rate are changed, thereby adjusting the water output intensity of rain head 9 and mist nozzle 10. By controlling the number of nozzles in operation, the rainfall coverage and total rainfall are changed, and the combination of both allows for the simulation of rainfall of different intensities. The combined design of the rain head 9 and the mist nozzle 10 can simulate rainfall of various forms and intensities, ranging from drizzle to torrential rain, covering a variety of rainfall conditions that may be encountered in actual engineering projects, thus improving the realism of rainfall simulation. By adjusting the power of the water pump 29 and the number of nozzles in operation, the operation is simple and the rainfall intensity can be precisely controlled, providing reliable experimental conditions for studying the impact of different rainfall intensities on the stability of soil and rock masses, and enriching the dimensions of experimental data.

[0036] Furthermore, in the support device, the airbag 18 and waterbag 45 of the confining pressure implementation device are both made of flexible materials and are closely fitted with the thin plastic plate 49 to ensure uniform pressure transmission.

[0037] The airbag 18 and waterbag 45 are made of flexible materials. Based on the deformation characteristics of flexible materials, they can fit tightly against the thin plastic plate 49 under pressure, avoiding gaps and ensuring that the pressure can be fully and evenly transmitted to the thin plastic plate 49. The thin plastic plate 49 has a certain rigidity, which can further evenly distribute the pressure transmitted by the airbag 18 and waterbag 45 to the rock and soil mass, preventing local pressure concentration. The airbags 18 and 45, made of flexible materials, are tightly fitted to the thin plastic plate 49, ensuring no dead zones or sudden local pressure changes during pressure transmission. This results in uniform confining pressure across all parts of the soil and rock mass, effectively preventing localized damage or data distortion caused by uneven pressure. Uniform pressure transmission provides excellent conditions for accurately studying the stability of soil and rock masses under different confining pressures, enhancing the reliability of experimental results.

[0038] Furthermore, the base 1 of the drainage device is equipped with a water valve 6 to control the drainage rate of the seepage storage chamber 5, the rain shower water supply tank 34 of the rain shower device is equipped with an outlet 33 to control the water supply flow, the water inlet pipe channel 2 is made of corrosion-resistant pipe material and is sealed to the water inlet hole 7 of the base, and one end of the rain shower water supply tank 34 is equipped with an inlet 27.

[0039] In the drainage device, water valve 6 adjusts the flow rate of seepage water at the outlet of seepage storage chamber 5 by changing the valve opening, based on the principles of fluid mechanics, thereby controlling the drainage rate and simulating the seepage environment of soil and rock under different drainage conditions. In the rainmaking device, the outlet 33 of the rainwater supply tank 34 controls the water supply flow by adjusting the opening, ensuring stable water supply to the rainmaking device; the inlet pipe channel 2 uses corrosion-resistant pipe material, which can prevent the pipe material from being corroded by water or impurities in the water during long-term use, extending its service life; the inlet pipe channel 2 is sealed to the base inlet hole 7, preventing water leakage based on the sealing principle, and avoiding changes in rainfall parameters due to water leakage; the inlet 27 of the rainwater supply tank 34 is used to replenish the water source, ensuring a continuous water supply to the rainmaking device. Water valve 6 allows for flexible adjustment of the drainage rate, simulating different drainage conditions such as permeable and impermeable layers. This provides experimental conditions for studying the impact of different drainage environments on the stability of soil and rock masses, enriching the dimensions of experimental research. Outlet 33 controls the water supply flow rate, ensuring stable rainfall intensity and improving the accuracy of rainfall simulation. Corrosion-resistant pipes extend the service life of the inlet pipe channel 2, reducing device maintenance costs; sealed connections prevent leakage, ensuring accurate rainfall parameters and reducing experimental errors. Inlet 27 ensures continuous water supply, guaranteeing smooth operation of long-term experiments and enhancing the practicality and reliability of the device.

[0040] When using the experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures during rainfall, the test platform 50 is first placed on a horizontal experimental site. The test platform support rod 51 is installed and adjusted to a stable state, ensuring that the test platform 50 is horizontal and reliably bears the load. The base 1 is fixed in the designated position on the test platform 50, and permeable stones 12 are installed on the permeable stone base 11 of the base 1, ensuring that the permeable stones 12 are tightly fitted to the base 1 without gaps. Installation of the baffle and telescopic rod: Install the baffle 16 around the edge of the base 1. Adjust the relative position of the sleeve and telescopic rod of the telescopic rod 17 according to the required experimental space height, so that the top of the telescopic rod 17 fits against the baffle 16, and lock it in place using the support rod fixing bolts 14. At the same time, ensure that the support rod base 13 at the bottom of the telescopic rod 17 is in close contact with the test bench 50, and that the support rod pad 15 at the top is in uniform contact with the baffle 16, ensuring that the baffle 16 is firmly fixed and does not wobble. Arrangement of the confining pressure implementation device: The confining pressure implementation device is laid inside the baffle 16. First, the water in the water bladder 45 is completely drained, and the water bladder drain outlet 46 is closed. The water bladder 45 is then evenly laid inside the water bladder chamber 25, ensuring that the water bladder 45 is wrinkle-free and undamaged. Next, the air bladders 18 are evenly laid inside the air bladder chamber 3. Each air bladder 18 is connected via an air guide pipe 48, forming a continuous unit. Then, the air bladder inlet pipe 22 is connected to the external inflation device, and the air bladder exhaust outlet 23 is closed. Finally, a thin plastic sheet 49 is laid on the outside of the water bladder 45 and air bladder 18, ensuring that the thin plastic sheet 49 is tightly fitted to the water bladder 45 and air bladder 18 without gaps. Pressure monitoring device debugging: Install the pressure sensor in the pressure sensor groove 20, fix the sensor position with the pressure sensor gasket 19, and ensure that the sensor is in close contact with the thin plastic plate 49 or the soil and rock. Pass the pressure sensor data transmission line 42 through the pressure sensor line tube 31 and connect it to the pressure sensor 43. Turn on the pressure sensor 43 for debugging to confirm that the pressure data acquisition and display are normal and there is no signal interference or data abnormality. Rainfall and drainage device inspection: Connect the graduated cylinder 40 to the rainwater supply tank 34 through the inlet pipe 28, and check whether the inlet pipe 28 is unobstructed and free from blockages or leaks. Fill the rainwater supply tank 34 with sufficient clean water, turn on the water pump 29, and test the water flow of the outlet pipe 32 and the inlet pipe channel 2. Observe whether the water output from the rain head 9 and the mist nozzle 10 is uniform, and adjust the power of the water pump 29 to confirm that the rainfall intensity can be adjusted normally. At the same time, check the drainage device: close the water valve 6, fill the seepage storage chamber 5 with a small amount of clean water, open the water valve 6, and observe whether the clean water can flow smoothly into the drainage tank 37 through the base drain hole 8 and the drainage tank inlet pipe 36. After being filtered by the high-density filter plate 30, it is discharged into the drainage bucket 41 through the drain pipe 39, ensuring that the drainage channel is unobstructed and free from blockages or leaks. Phase II Experimental Operation Placement of soil and rock samples: According to the experimental design requirements, the soil and rock samples to be tested are evenly laid on the permeable stone 12 of the base 1 to ensure that the sample thickness and density are uniform, and that they are in close contact with the thin plastic plate 49 without obvious gaps, and to avoid loosening or protrusion of the sample edges. Confining pressure application: First, slowly inject water into the water bladder 45 through the water inlet 44 until water overflows from the water bladder 45. Then, close the water inlet 44. At this point, a stable and uniform liquid pressure is formed inside the water bladder 45, providing initial confining pressure for the soil and rock mass. Subsequently, turn on the external inflation device and slowly inflate the air bladder 18 through the air inlet pipe 22. According to the confining pressure value required for the experiment, the pressure change is monitored in real time by the pressure sensor 43. When the pressure reaches the set value, inflation is stopped, and the valves of the inflation device and the air inlet pipe 22 are closed to maintain stable confining pressure. Rainfall Simulation: Based on the designed rainfall intensity and amount, measure the corresponding volume of clean water in the graduated container 40, open the valve of the inlet pipe 28, and inject the clean water into the rainwater supply tank 34. Turn on the water pump 29 and adjust its power to the set value. Simultaneously, depending on the rainfall pattern requirements, select and turn on the rain head 9, the mist nozzle 10, or a combination of both, so that rainwater is transported to the nozzles through the inlet pipe channel 2 to form simulated rainfall, which is evenly sprayed onto the surface of the soil and rock sample. During the rainfall, the water volume is replenished in real time through the graduated container 40 to maintain a stable rainfall amount. At the same time, the pressure sensor 43 continuously records the pressure change data of the soil and rock sample to observe the deformation and seepage of the soil and rock sample. Infiltration Treatment and Monitoring: During rainfall, rainwater gradually seeps into the soil and rock sample. Excess infiltration water permeates through the soil and rock sample to the permeable stone 12, and then flows into the infiltration storage chamber 5 through the infiltration hole 4. According to the experimental design requirements, the opening of the water valve 6 is adjusted to control the infiltration discharge rate, simulating the soil and rock seepage environment under different drainage conditions. The infiltration water enters the drainage hole 8 of the base through the water valve 6, and then flows into the drainage tank 37 through the drainage tank inlet pipe 36. After being filtered by the high-density filter plate 30 to remove soil and rock particles and impurities in the infiltration water, it is discharged into the drainage bucket 41 through the drainage pipe 39. The experimenters regularly record the amount of infiltration water in the drainage bucket 41, analyze parameters such as the infiltration rate and water holding capacity of the soil and rock, and observe whether the drainage is clear to determine whether there is particle loss in the soil and rock. Multi-condition parameter adjustment: To test the stability of soil and rock under different confining pressures, the inflation volume of the air bladder 18 can be slowly adjusted via the inflation device, or the water volume in the water bladder 45 can be added / discharged through the water inlet 44 to change the confining pressure value. After the pressure stabilizes, the above rainfall simulation steps can be repeated, and experimental data under different confining pressures can be recorded. To test different rainfall intensities, the power of the water pump 29 can be adjusted or the number of nozzles opened can be changed to adjust the rainfall intensity, maintain stable confining pressure, and record the pressure changes and seepage data of the soil and rock under different rainfall intensities. Three experimental completion stages Stopping Rainfall and Releasing Confining Pressure: After a certain working condition experiment is completed, first turn off the water pump 29 to stop rainfall, then close the valve of the inlet pipe 28 between the graduated cylinder 40 and the rainwater supply tank 34. Subsequently, slowly open the airbag vent 23 to release the gas inside the airbag 18. After the pressure in the airbag 18 drops to atmospheric pressure, close the airbag vent 23. Then open the waterbag drain 46 to drain the water inside the waterbag 45 until the waterbag 45 is empty, then close the waterbag drain 46. Data processing and device cleaning: Turn off the pressure sensor 43, and process the pressure data, rainfall data, and infiltration data recorded during the experiment to form a complete experimental data report. Then, remove the soil and rock samples, and clean the residual soil and rock particles from the surfaces of the base 1, permeable stone 12, and thin plastic sheet 49 to ensure no impurities remain. Clean the rainwater supply tank 34, graduated cylinder 40, drainage tank 37, drainage bucket 41, and other components, drain any residual water from each device, and check that all components are intact and free from damage or aging. Device Storage and Maintenance: Disassemble detachable components such as the pressure sensor, inflation device, and water pump 29, clean and maintain them individually, and store them properly. Adjust the telescopic rod 17, remove the baffle 16, and classify and place each component according to storage requirements to avoid collision damage. Finally, clean the fixed components such as the test bench 50 and test bench support rod 51, and check that the connections are secure to prepare for the next experiment.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures during rainfall, characterized in that: It includes support devices, water supply devices, rainfall devices, confining pressure implementation devices, drainage devices, and pressure monitoring devices; The support device includes a test bench (50), a base (1), a baffle (16) and a telescopic rod (17); the entire test device is placed on the test bench (50); the baffle (16) is installed on the base (1) and fixed by the telescopic rod (17); The rainfall device includes a rain water supply tank (34), a scale barrel (40), a water inlet pipe channel (2), a rain head (9), and an aerosol nozzle (10); the scale barrel (40) is connected to the rain water supply tank (34) through a water inlet pipe (28), and the water pump (29) in the rain water supply tank (34) is connected to the base water inlet hole (7) of the base (1) through a water outlet pipe (32). The water flows through the water inlet pipe channel (2) to the rain head (9) and forms simulated rainfall through the aerosol nozzle (10). The rainfall amount is measured and controlled by the scale barrel (40). The confining pressure implementation device is located inside the baffle (16) and includes an airbag chamber (3), a waterbag chamber (25), an airbag (18), a waterbag (45), a thin plastic plate (49), an airbag inlet (21), an airbag inlet pipe (22), an airbag outlet (23), an airbag outlet pipe (24), a waterbag inlet (44), a waterbag outlet (46), and a waterbag outlet pipe (47); the waterbag (45) is laid in the waterbag chamber. (25) Inside, the airbag (18) is laid in the airbag chamber (3); the airbag inlet pipe (22) is connected to the inflation device, and the water bag inlet (44) is used for water injection. Through the inflation of the airbag (18) and the water bag (45) and the water injection, the uniform confining pressure is transmitted to the rock and soil through the thin plastic plate (49); the top of the water bag chamber (25) is provided with a water injection chamber (26), and the airbags (18) are connected to each other through the air guide pipe (48); The drainage device includes a base drainage hole (8), a seepage storage chamber (5), a drainage tank inlet (35), a drainage tank inlet pipe (36), a drainage tank (37), a drainage outlet (38), a high-density filter plate (30), a drainage pipe (39), and a drainage bucket (41). Seepage water enters the seepage storage chamber (5) through the seepage hole (4) of the base (1), and then enters the drainage tank (37) through the base drainage hole (8) and the drainage tank inlet pipe (36). After being filtered by the high-density filter plate (30), it is discharged into the drainage bucket (41) through the drainage pipe (39).

2. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: The test bench (50) is supported by a test bench support rod (51), and the base (1) includes a permeable stone base (11) on which permeable stones (12) are provided.

3. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: The telescopic rod (17) consists of a sleeve and a telescopic rod. The sleeve and the telescopic rod are locked and fixed by a support rod fixing bolt (14). A support rod base (13) is installed at the bottom of the telescopic rod (17), and a support rod gasket (15) is installed at the top of the telescopic rod (17).

4. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: The pressure monitoring device includes a pressure sensor, a pressure sensor pad (19), a pressure sensor groove (20), a pressure sensor line tube (31), and a pressure sensor (43). The pressure sensor is set in the pressure sensor groove (20) and fixed by the pressure sensor pad (19). The pressure sensor data transmission line (42) is connected to the pressure sensor (43) through the pressure sensor line tube (31).

5. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: In the confining pressure implementation device, the water bladder (45) needs to be drained before it is laid, and the water bladder drain outlet (46) is closed after it is laid, and water is injected until it overflows; after the air bladder (18) is laid, the air bladder exhaust outlet (23) is closed, and the air is slowly inflated by the inflation device to adjust the confining pressure.

6. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: In the rainfall device, the rain head (9) and the mist nozzle (10) are combined and can simulate rainfall of different intensities by adjusting the power of the water pump (29) and the number of nozzles turned on.

7. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: In the support device, the air bladder (18) and water bladder (45) of the confining pressure implementation device are both made of flexible materials and are closely fitted with the thin plastic plate (49) to ensure uniform pressure transmission.

8. The experimental apparatus for analyzing the stability of soil and rock masses under different confining pressures under rainfall conditions as described in claim 1, characterized in that: The base (1) of the drainage device is equipped with a water valve (6) to control the drainage rate of the seepage storage chamber (5). The rain shower water supply tank (34) of the rain shower device is equipped with an outlet (33) to control the water supply flow. The water inlet pipe channel (2) is made of corrosion-resistant pipe material and is sealed to the water inlet hole (7) of the base. One end of the rain shower water supply tank (34) is equipped with an inlet (27).

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