Tailings test system and tailings test method

Abstract

This application relates to the field of geotechnical engineering technology, specifically disclosing a tailings testing system and a tailings testing method. The tailings testing system includes: a tailings simulation device comprising at least three layers arranged vertically in sequence; an environmental simulation control device for applying time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads to the tailings simulation device; and a detection device comprising a mechanical detection module, a heat-water-phase change detection module, and a chemical detection module. The mechanical detection module is located outside the tailings simulation device and is used to collect mechanical response data of the tailings simulation device. The heat-water-phase change detection module is embedded within the layered structure and is used to collect temperature data, pore water pressure data, and ice-water phase change data of the layered structure under freeze-thaw cycle loads and rainfall infiltration loads. The chemical detection module is located at the bottom of the tailings simulation device and is used to collect chemical characteristic data of the leachate after filtration through at least three layers of the layered structure.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, and in particular to a tailings testing system and a tailings testing method. Background Technology

[0002] Tailings dams are sites where mining companies store tailings, consisting of an initial dam and a subsequent accumulation dam. In high-altitude and cold regions, tailings dams are subjected to the combined effects of freeze-thaw cycles and rainfall infiltration over long periods. Freeze-thaw cycles alter the internal structure of tailings through water phase change, leading to changes in its strength and permeability; rainfall infiltration causes changes in pore water pressure and leaching of pollutants. The coupled effect of these two factors impacts the stability and environmental safety of tailings dams.

[0003] Some tailings test devices in related technologies can simulate the impact of freeze-thaw cycles on tailings, but cannot simulate rainfall infiltration; others can simulate the impact of rainfall infiltration on tailings, but cannot simulate freeze-thaw cycles, thus failing to fully reflect the actual impact of the coupled effects of freeze-thaw cycles and rainfall on tailings ponds. Summary of the Invention

[0004] This application discloses a tailings testing system and a tailings testing method, which can simulate the actual impact of the coupling effect of freeze-thaw cycles and rainfall infiltration on tailings.

[0005] The first aspect of this application provides a tailings testing system, comprising: a tailings simulation device including three layers arranged vertically in sequence; an environmental simulation control device for applying time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads to the tailings simulation device; and a detection device including a mechanical detection module, a thermal-water-phase change detection module, and a chemical detection module. The mechanical detection module is disposed outside the tailings simulation device and is used to collect mechanical response data of the tailings simulation device. The thermal-water-phase change detection module is embedded within the layered structure and is used to collect temperature data, pore water pressure data, and ice-water phase change data of the layered structure under the action of the freeze-thaw cycle loads and the rainfall infiltration loads. The chemical detection module is disposed at the bottom of the tailings simulation device and is used to collect chemical characteristic data of the leachate after filtration through the at least three layers.

[0006] In one possible implementation, the hot-water-phase change detection module includes multiple sets of detection components, which are disposed at multiple different heights within the layer structure, or the multiple sets of detection components are disposed within the layer structure at different heights.

[0007] In one possible implementation, each set of the detection components includes: a temperature sensor for acquiring temperature data; a pore water pressure gauge for acquiring pore water pressure data; and an ice content detector for acquiring ice-water phase change data; wherein the temperature data, the pore water pressure data, and the ice-water phase change data are used to establish a quantitative relationship model of water migration-phase change-pressure response driven by temperature.

[0008] In one possible implementation, the temperature sensor, the pore water pressure gauge, and the ice content detector are embedded at the same location within the layer structure to synchronously collect the temperature data, the pore water pressure data, and the ice-water phase change data at that location.

[0009] In one possible implementation, the at least three layers arranged vertically in sequence include: a contaminant layer, located at the top of the tailings simulation device, for containing contaminants; a barrier control layer, located below the contaminant layer, for containing the barrier control medium to be tested; and a protected layer, located below the barrier control layer, for containing the protected medium.

[0010] In one possible implementation, the mechanical detection module includes: a laser displacement sensor, disposed on the top of the tailings simulation device, for collecting axial deformation data of the tailings simulation device; and a radial strain ring, sleeved on the outer wall of the tailings simulation device, for collecting radial deformation data of the tailings simulation device.

[0011] In one possible implementation, the chemical detection module includes: a pH meter, located at the bottom of the tailings simulation device, for collecting acidity and alkalinity data of the leachate; and a conductivity meter, located at the bottom of the tailings simulation device, for collecting total ion concentration data of the leachate.

[0012] In one possible implementation, the environmental simulation control device further includes a controller and a rainfall simulation module, the rainfall simulation module comprising: a water tank; a rainfall infiltration layer disposed on top of the tailings simulation device, the rainfall infiltration layer including a plurality of permeable holes; and an array of solenoid valves, each of which is connected to the controller and corresponds to one of the permeable holes.

[0013] In one possible implementation, the environmental simulation control device further includes a controller and a freeze-thaw simulation module. The freeze-thaw simulation module includes: a low-temperature control box and a high-temperature control box, which store circulating media at different temperatures, respectively; a circulation pipeline connected to the tailings simulation device for conveying the circulating media to the layer structure; a circulation pump located in the circulation pipeline and connected to the controller for driving the flow of the circulating media; and an electromagnetic switching valve located in the circulation pipeline and connected to the controller for selectively introducing the circulating media from the low-temperature control box or the high-temperature control box into the circulation pipeline.

[0014] In one possible implementation, the tailings simulation device has a leachate collection structure at its bottom, and the chemical detection module is located within the leachate collection structure. The leachate collection structure includes: a leachate collection pipe located at the bottom of the tailings simulation device; a collection pool connected to the leachate collection pipe for containing the leachate after filtration through the at least three-layer structure; and a control switch located on the leachate collection pipe for controlling the discharge and collection of the leachate.

[0015] An embodiment of the second aspect of this application provides a tailings testing method applied to the tailings testing system provided in the first aspect of this application. The method involves constructing a tailings simulation device using a layered compaction technique for at least three layers. A detection device is installed at the target location of each layer. Initial state data of the tailings simulation device is collected using the detection device, including initial mechanical response data, initial temperature data, initial pore water pressure data, initial ice-water phase transition data, and initial chemical characteristic data. A time-series superimposed freeze-thaw cycle load and rainfall infiltration load are applied to the tailings simulation device using an environmental simulation control device. During the load application process, current state data of the tailings simulation device is collected using the detection device, including current mechanical response data, current temperature data, current pore water pressure data, current ice-water phase transition data, and current chemical characteristic data. The current state data and the initial state data are compared and analyzed to establish the correlation between the response characteristics of each layer and the pollutant migration patterns under the coupled effect of freeze-thaw cycle load and rainfall infiltration load.

[0016] Compared with the prior art, the beneficial effects of this application are: The tailings test system coupled with freeze-thaw cycles and rainfall infiltration provided in this application embodiment, by setting up a tailings simulation device including at least three layers, applies time-superimposed freeze-thaw cycle loads and rainfall infiltration loads through an environmental simulation control device, and collects mechanical response data, temperature data, pore water pressure data, ice-water phase change data, and chemical characteristic data through mechanical detection modules, thermal-water-phase change detection modules, and chemical detection modules in the detection device, respectively. It can simulate the actual environment of tailings under the coupled action of freeze-thaw cycles and rainfall infiltration, and obtain multi-physics field response data inside each layer of the structure, providing a basis for analyzing the mechanical response characteristics, hydrothermal response characteristics, and pollutant migration characteristics of tailings under the coupled action of freeze-thaw cycles and rainfall infiltration.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

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

[0019] Figure 1 This is a schematic diagram of the tailings test system provided in the embodiments of this application; Figure 2 This is one of the structural schematic diagrams of the tailings simulation device in the tailings test system provided in the embodiments of this application; Figure 3 This is the second schematic diagram of the tailings simulation device in the tailings test system provided in the embodiments of this application; Figure 4 A schematic diagram of the assembly structure of the tailings simulation device and circulation pipeline in the tailings test system provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the rainfall infiltration layer in the tailings test system provided in the embodiments of this application; Figure 6 This is a schematic flowchart of the tailings testing method provided in the embodiments of this application.

[0020] Explanation of reference numerals in the attached figures: 1-Tailings test system; 10-Tailings simulation device; 101-Layer structure; 1011-Contaminant layer; 1012-Barrier layer; 1013-Protected layer; 102-Water passage hole; 103-Glass cylinder; 104-Flange; 20-Environmental simulation control device; 201-Freeze-thaw simulation module; 2011-Low temperature control box; 2012-High temperature control box; 2013-Circulation pipeline; 2014-Circulation pump; 2015-Electromagnetic switching valve; 202-Rainfall simulation module; 2021-Water tank; 2022-Rainfall infiltration layer; 20221-Water permeable hole; 2023- Solenoid valve array; 203-Controller; 30-Detection device; 301-Mechanical detection module; 3011-Laser displacement sensor; 3012-Radial strain ring; 302-Thermo-water-phase change detection module; 3020-Detection component; 3021-Temperature sensor; 3022-Porous water pressure gauge; 3023-Ice content detector; 303-Chemical detection module; 3031-pH meter; 3032-Conductivity tester; 304-Leachate collection structure; 3041-Leachate collection pipe; 3042-Collection tank; 3043-Control switch; 40-Acquisition device. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0023] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0024] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0025] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0026] In the tailings test devices of related technologies, there is a common problem that they can only simulate a single physical or chemical process, and cannot truly reproduce the hydraulic-mechanical-chemical multi-field response process of the tailings system under the coupling effect of freeze-thaw cycle and rainfall infiltration.

[0027] Based on this, the embodiments of this application provide a tailings test system to simulate, measure and quantitatively evaluate the impact of the dynamic coupling effect of two environmental processes, freeze-thaw cycle and rainfall infiltration, on the tailings system in a laboratory environment.

[0028] like Figure 1 As shown, an embodiment of the first aspect of this application provides a tailings test system 1, which includes a tailings simulation device 10, an environmental simulation control device 20, and a detection device 30.

[0029] The tailings simulation device 10 serves as an experimental platform for physically simulating the layered geological structure of a tailings dam. The tailings simulation device 10 includes at least three layers 101 arranged vertically in sequence. By setting up multiple layers 101, the layered distribution of different materials and functions within the tailings dam can be simulated. The at least three layers 101 may include a pollutant layer 1011, a control layer 1012, and a protected layer 1013, etc.

[0030] The environmental simulation control device 20 is connected to the tailings simulation device 10 and is used to apply time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads to the tailings simulation device 10. The environmental simulation control device 20 can simulate the freeze-thaw cycle process and rainfall infiltration process in the natural environment, and superimpose these two processes in time to study the impact on tailings when they act simultaneously.

[0031] The detection device 30 is integrated into the tailings simulation device 10 and is used to collect multi-physics response data of the tailings simulation device 10 under freeze-thaw cycle loads and rainfall infiltration loads. The detection device 30 includes a mechanical detection module 301, a thermal-water-phase change detection module 302, and a chemical detection module 303. By setting up three different types of detection modules 301, mechanical response data, thermal-water-phase change data, and chemical characteristic data can be collected respectively, thereby realizing comprehensive measurement of the tailings system under freeze-thaw cycle loads and rainfall infiltration loads.

[0032] Specifically, the mechanical testing module 301 is located on the exterior of the tailings simulation device 10. For example, the mechanical testing module 301 can be located on the top or outer periphery of the tailings simulation device 10. The mechanical testing module 301 is used to collect mechanical response data of the tailings simulation device 10. The mechanical response data can reflect the deformation characteristics of the tailings simulation device 10 under freeze-thaw cycle loads and rainfall infiltration loads, such as axial deformation and radial deformation.

[0033] The thermal-water-phase change detection module 302 is embedded within the layered structure 101 and is used to collect temperature data, pore water pressure data, and ice-water phase change data of the layered structure 101 under freeze-thaw cycle load and rainfall infiltration load. The temperature data, pore water pressure data, and ice-water phase change data can respectively reflect the temperature changes, moisture migration driving force changes, and unfrozen water to ice ratio changes within the layered structure 101.

[0034] For example, the location of a freezing front can be determined by comparing temperature data at different depths at the same time point. By comparing the time series of temperature data and ice content data at the same depth, the temporal correspondence between the formation and melting processes of ice lenses and temperature changes can be determined. By comparing ice content data and pore water pressure data, the characteristics of pore water pressure changes during ice lens growth can be analyzed. By comparing and analyzing these three types of data by time and depth, the temporal and spatial correspondences between temperature changes, water migration, and ice-water phase transitions can be obtained.

[0035] A chemical detection module 303 is located at the bottom of the tailings simulation device 10 and is used to collect chemical characteristic data of the leachate after it has been filtered through at least three layers of the structure 101. The chemical characteristic data can reflect the migration characteristics of pollutants during the leaching process and the fouling resistance performance of the tailings simulation device 10, such as pH, total ion concentration, etc.

[0036] The tailings test system 1 may also include a data acquisition device 40, which may be a computer with data processing capabilities. The detection device 30 is electrically connected to the data acquisition device 40 so that the data acquisition device 40 can analyze the acquired data.

[0037] Thus, this application provides a tailings test system 1 that couples freeze-thaw cycles with rainfall infiltration. By setting up a tailings simulation device 10 including at least three layers 101, and applying time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads through an environmental simulation control device 20, and collecting mechanical response data, temperature data, pore water pressure data, ice-water phase change data, and chemical characteristic data through the mechanical detection module 301, the thermal-water-phase change detection module 302, and the chemical detection module 303 in the detection device 30, the actual environment of the tailings under the coupled action of freeze-thaw cycles and rainfall infiltration can be simulated, and multi-physics field response data inside each layer 101 can be obtained, providing a basis for analyzing the mechanical response characteristics, hydrothermal response characteristics, and pollutant migration characteristics of the tailings under the coupled action of freeze-thaw cycles and rainfall infiltration.

[0038] In some embodiments, such as Figure 2 As shown, the tailings simulation device 10 can be designed with a detachable multi-layer structure 101. Specifically, the tailings simulation device 10 may include a pollutant layer 1011, a barrier layer 1012, and a protected layer 1013.

[0039] The pollutant layer 1011 is located at the top of the tailings simulation device 10 and is used to contain pollutants to simulate the pollution source of the tailings dam. The pollutant layer 1011 can be filled with polluted tailings, for example, tailings sand mixed evenly with a solution containing specific heavy metal ions and then filled, or it can be filled with actual collected polluted tailings samples.

[0040] The barrier layer 1012 is located below the pollutant layer 1011 and is used to contain the barrier medium to be tested, simulating the barrier effect of artificial barriers on pollutants. The barrier layer 1012 is the test variable area, which can be filled with different types of barrier media according to the test needs, such as: natural materials such as clay and vegetation layer; engineering materials such as geomembrane, waterproof blanket, geosynthetic clay cushion layer, and geocomposite materials; or modified materials such as sand-bentonite mixture, lime-cement improved soil, cement-tailings mixture, and biochar improved materials. It is used to compare and test the seepage prevention and pollution prevention performance of different barriers under freeze-thaw-seepage coupling effect.

[0041] The protected layer 1013 is located below the barrier layer 1012 and is used to contain the protected medium to simulate the protected downstream environment. The protected layer 1013 can be filled with tailings, or, depending on the simulated object, with natural soil, water-saturated aquifer material, or rock material.

[0042] In some embodiments, such as Figure 3As shown, the tailings simulation device 10 adopts a detachable structure. Three sections of high-strength transparent plexiglass cylinders 103, for example, with an inner diameter of 30cm and a height of 50cm each, are connected by flanges 104 and sealing rings to form a detachable tailings column with a total height of 150cm. Holes are pre-drilled in the cylinder wall and sealed valves are installed as lateral water passage holes 102.

[0043] The protected layer 1013 is constructed as follows: First, a filter screen and gravel filter layer are laid at the bottom, then tailings are filled in, and compacted with a light compactor every 5-10 cm until the designed height, such as 50 cm, is reached. During the filling process, detection devices 30 are installed at a predetermined depth, such as: a pore water pressure gauge 3022, a radial strain ring 3012, an ice content detector 3023, and a temperature sensor 3021. Then, the leachate collection pipe 3041 at the bottom is connected to the collection tank 3042.

[0044] The barrier control layer 1012 is constructed as follows: The intermediate section of the cylinder is installed, and the barrier control medium to be tested is filled in. This layer is a key area for testing; the density of the testing components 3020 can be higher, especially in areas close to where ice lenses may form, such as 10-30 cm below the top. During the filling process, a pore water pressure gauge 3022, a radial strain ring 3012, an ice content detector 3023, and a temperature sensor 3021 are inserted at a predetermined depth.

[0045] The construction method of pollutant layer 1011 is as follows: Install the top cylinder and fill it with prepared tailings. During the filling process, insert a pore water pressure gauge 3022, a radial strain ring 3012, an ice content detector 3023, and a temperature sensor 3021 at a predetermined depth. A certain space is reserved at the top for installing the rainwater infiltration layer 2022.

[0046] Thus, the tailings simulation device 10, by setting up a three-layer structure 101, allows pollutants in the pollutant layer 1011 to migrate downwards with the water flow under the infiltration of rainfall. When the pollutants flow through the barrier layer 1012, the barrier medium in the barrier layer 1012 acts as a barrier to the pollutants. Some pollutants may be adsorbed, precipitated, or trapped by the barrier medium, while other pollutants may penetrate the barrier layer 1012 and enter the protected layer 1013. By collecting temperature data, pore water pressure data, ice-water phase change data, and chemical characteristic data of leachate from each layer 101 using the detection device 30, the concentration changes of pollutants during their downward migration, the time and amount of penetration through the barrier layer 1012, and the barrier effect of different barrier media on pollutants can be analyzed.

[0047] In some embodiments, such as Figure 1As shown, the sidewall of the tailings simulation device 10 can be provided with multiple water passage holes 102 at different heights. The water passage holes 102 can be used for water replenishment or water pumping. This can simulate the rise and fall of the groundwater level. By replenishing water into the tailings simulation device 10 through the water passage holes 102, or by pumping water out of the tailings simulation device 10 through the water passage holes 102, the water level inside the tailings simulation device 10 can be adjusted to simulate changes in the groundwater level.

[0048] In some embodiments, the thermal-water-phase change detection module 302 may include multiple sets of detection components 3020. The multiple sets of detection components 3020 may be respectively disposed at multiple different heights within the same layer structure 101, or they may be disposed in different layer structures 101. Detection components 3020 located within a layer structure 101 may be disposed at a single height.

[0049] By setting detection components 3020 at different heights, temperature data, pore water pressure data, and ice-water phase change data at different heights along the depth profile can be acquired. When multiple sets of detection components 3020 are set at multiple different heights within the same layer structure 101, the changes in temperature data, pore water pressure data, and ice-water phase change data within the layer structure 101 along the height direction of the layer structure 101 can be acquired. When multiple sets of detection components 3020 are set in different layer structures 101, the differences in temperature data, pore water pressure data, and ice-water phase change data between different layer structures 101 can be acquired, as well as the changes in temperature data, pore water pressure data, and ice-water phase change data within each layer structure 101 as pollutants in the pollutant layer 1011 migrate downwards under the action of rainfall infiltration.

[0050] Temperature data collected at different altitudes at the same time point can reflect the temperature distribution along depth. Based on the temperature distribution, the location and depth of the freezing front within the tailings simulation device 10 can be determined. Pore water pressure data collected at different altitudes at the same time point can reflect the changes in pore water pressure along depth. Based on the pore water pressure gradient, the direction and rate of water migration can be determined. Ice-water phase transition data collected at different altitudes at the same time point can reflect the distribution of the unfrozen water to ice ratio along depth. Based on the ice content distribution, the formation location and growth status of ice lenses can be determined.

[0051] By comparing and analyzing temperature data, pore water pressure data, and ice-water phase transition data at the same altitude point in a time series manner, the temporal relationship between temperature changes, pore water pressure changes, and ice-water phase transition at that altitude can be obtained. By comparing and analyzing data from different altitude points in a time series manner, the propagation process and influence of temperature changes, pore water pressure changes, and ice-water phase transition along the depth direction can be obtained.

[0052] When the detection components 3020 are respectively set in different layer structures 101, the variation patterns of temperature data, pore water pressure data and ice-water phase change data between different layer structures 101 can be compared, and the response differences of each layer structure 101 under freeze-thaw cycle load and rainfall infiltration load can be analyzed.

[0053] In this way, by combining the temperature data, pore water pressure data, and ice-water phase transition data collected by the detection components 3020 at various heights, a quantitative relationship model of water migration, phase transition, and pressure response driven by temperature can be established, thereby describing the dynamic evolution process of the temperature field, pore water pressure field, and ice-water phase transition field.

[0054] In some embodiments, such as Figure 1 As shown, each detection assembly 3020 includes a temperature sensor 3021, a pore water pressure gauge 3022, and an ice content detector 3023. The temperature sensor 3021 is embedded within the layer structure 101 and is used to collect temperature data. The pore water pressure gauge 3022 is embedded within the layer structure 101 and is used to collect pore water pressure data. The ice content detector 3023 is embedded within the layer structure 101 and is used to collect ice-water phase change data.

[0055] The temperature data collected by temperature sensor 3021 can be used to measure the temperature change inside layer structure 101 over time and depth. Based on the temperature data, the time it takes for the temperature to reach a specific value at different depths, as well as the temperature distribution along the depth direction, can be determined.

[0056] The pore water pressure data collected by the pore water pressure gauge 3022 can be used to measure the changes in pore water pressure over time and depth. Based on this data, the driving forces of water migration and the formation process of frost heave pressure can be analyzed.

[0057] The ice-water phase transition data collected by the 3023 ice content analyzer can be used to determine the change in the ratio of unfrozen water to ice over time and depth. Based on the ice-water phase transition data, the formation location and growth of ice lenses can be determined, as well as the melting process of ice lenses with temperature changes.

[0058] In some embodiments, the temperature sensor 3021, the pore water pressure gauge 3022, and the ice content detector 3023 are embedded at the same location within the layer structure 101 to synchronously collect temperature data, pore water pressure data, and ice-water phase change data at that location.

[0059] In this way, by comparing the temperature data, pore water pressure data, and ice-water phase change data collected synchronously at the same location, we can analyze the time correspondence between temperature changes and ice-water phase change at that location, as well as the characteristics of pore water pressure changes during the ice-water phase change process.

[0060] Specifically, temperature baselines for phase transitions can be determined based on temperature data, the formation and melting processes of the phase transition interface and ice lenses can be tracked based on ice-water phase transition data, and the driving force changes for water migration can be measured based on pore water pressure data. Data collected simultaneously from these three sources can be used to establish a quantitative model of the relationship between water migration, phase transition, and pressure response driven by temperature gradients.

[0061] In some embodiments, such as Figure 1 As shown, the mechanical detection module 301 includes a laser displacement sensor 3011 and a radial strain ring 3012.

[0062] A laser displacement sensor 3011 is mounted on the top of the tailings simulation device 10 to collect axial deformation data of the device. The laser displacement sensor 3011 can be vertically aligned with the top of the tailings simulation device 10, measuring the height change of the device and outputting the height change data. . The difference between the real-time height and the initial height, i.e. = - ,in Let be the height of the tailings simulation device at time t. The initial height of the tailings simulation device 10.

[0063] According to the output of laser displacement sensor 3011 The time-varying curves can determine the maximum height change of the tailings simulation device 10 during the frost heave process and the final height change during the thawing process. During the freezing stage, The maximum value of the frost heave is the amount that gradually increases over time. During the melting stage, It gradually decreases over time, and its final stable value is... .

[0064] Maximum frost heave ,in This represents the maximum height of the tailings simulation device 10 during the frost heave process. The initial height of the tailings simulation device 10 is given. The maximum frost heave reflects the maximum rise in height of the tailings simulation device 10 during the freezing process.

[0065] frost heave rate / 100% The frost heave rate reflects the relative deformation of the tailings simulation device 10 during the freezing process.

[0066] Maximum melting and settling volume ,in This represents the stable height of the tailings simulation device 10 after the melting and settling process. The maximum melting and settling volume reflects the settling height of the tailings simulation device 10 during the melting process.

[0067] Sinking coefficient / Sedimentation coefficient This reflects the degree of residual deformation of the tailings simulation device 10 after melting.

[0068] Thus, by comparing the frost heave rate under different freeze-thaw cycles... and the coefficient of sedimentation This allows for the analysis of the cumulative damage caused by freeze-thaw cycles to the tailings simulation device 10. Freeze-thaw rate. The change in the number of freeze-thaw cycles can reflect the structural deterioration trend of the tailings simulation device 10 during repeated freeze-thaw processes, and the melt-settlement coefficient. The variation in the number of freeze-thaw cycles reflects the cumulative irreversible deformation of the tailings simulation device 10 after thawing. The frost heave rate... and the coefficient of sedimentation By comparing the ice-water phase change data collected by the hot-water-phase change detection module 302, the correspondence between the growth position, growth thickness and macroscopic deformation of the ice lens body inside the tailings simulation device 10 can be analyzed.

[0069] like Figure 1 As shown, a radial strain ring 3012 is fitted onto the outer wall of the tailings simulation device 10 to collect radial deformation data of the tailings simulation device 10. The radial strain ring 3012 is horizontally fitted at different heights on the outer wall of the tailings simulation device 10, which can sense lateral deformation and output radial strain.

[0070] The expression for radial strain is: ,in This represents the change in diameter of the tailings simulation device 10. This is the initial diameter of the tailings simulation device.

[0071] Thus, based on the radial deformation data collected by the radial strain ring 3012 and the axial deformation data collected by the laser displacement sensor 3011, the true volumetric strain of the tailings simulation device 10 can be calculated. The true volumetric strain reflects the volume change during the frost heave process. The true volumetric strain is then compared with the frost heave rate. , sedimentation coefficient By conducting comparative analysis, the correspondence between internal structural damage and macroscopic deformation of the tailings simulation device 10 can be established.

[0072] In some embodiments, such as Figure 1As shown, the chemical detection module 303 includes a pH meter 3031 and a conductivity meter 3032. The pH meter 3031 is located at the bottom of the tailings simulation device 10 and is used to collect the acidity and alkalinity data of the leachate. The conductivity meter 3032 is located at the bottom of the tailings simulation device 10 and is used to collect the total ion concentration data of the leachate.

[0073] The leachate is a liquid obtained after percolation through at least three layers 101, containing contaminants that have migrated from the contaminant layer 1011. By measuring the pH and total ion concentration of the leachate in real time using a pH meter 3031 and a conductivity meter 3032, the migration characteristics of contaminants during the percolation process and the fouling resistance performance of the barrier layer 1012 can be evaluated.

[0074] In addition, leachate can be collected for chemical measurements of heavy metal concentration, turbidity, etc., to further analyze the specific components and concentrations of pollutants in the leachate.

[0075] In some embodiments, such as Figure 1 As shown, the environmental simulation control device 20 also includes a freeze-thaw simulation module 201, a rainfall simulation module 202, and a controller 203. The controller 203 is connected to the freeze-thaw simulation module 201 and the rainfall simulation module 202, and is used to control the working status of the freeze-thaw simulation module 201 and the rainfall simulation module 202.

[0076] The freeze-thaw simulation module 201 includes a low-temperature control box 2011, a high-temperature control box 2012, a circulation pipeline 2013, a circulation pump 2014, and a solenoid switching valve 2015. The low-temperature control box 2011 and the high-temperature control box 2012 store circulating media at different temperatures. The low-temperature control box 2011 can be filled with ethanol, with a temperature control range of -30°C to room temperature; the high-temperature control box 2012 can be filled with water, with a temperature control range of room temperature to 50°C.

[0077] The circulation pipeline 2013 is connected to the tailings simulation device 10 and is used to transport the circulating medium to the layer structure 101. For example... Figure 4 As shown, the circulation pipe 2013 can be wound around the outer wall of the tailings simulation device 10 to form a jacket around the tailings simulation device 10, and the temperature of the tailings simulation device 10 is controlled by the medium inside the circulation pipe 2013. The circulation pipe 2013 can be made of copper or silicone.

[0078] A circulation pump 2014 is installed in the circulation pipeline 2013 and connected to the controller 203 to drive the flow of the circulating medium. Through the circulation pump 2014, the circulating medium can be circulated in the circulation pipeline 2013 to achieve continuous heating or cooling of the tailings simulation device 10.

[0079] The electromagnetic switching valve 2015 is installed in the circulation pipeline 2013 and connected to the controller 203, and is used to selectively introduce the circulating medium in the low temperature control box 2011 or the circulating medium in the high temperature control box 2012 into the circulation pipeline 2013.

[0080] The process of implementing the freeze-thaw environment simulation module is as follows: A circulation pipe 2013 (copper pipe) is wound around the outer wall of the tailings simulation device 10 to form a jacket around the device. The inlet and outlet of the circulation pipe 2013 are connected to the low-temperature control box 2011 and the high-temperature control box 2012, respectively. A circulation pump 2014 and an electromagnetic switching valve 2015 are installed on the circulation pipe 2013, and a temperature curve is set via the controller 203. For example, the low-temperature chamber is set to -30°C, and circulation is initiated for 12 hours (freezing stage); then the valve is switched to circulate the medium in the high-temperature chamber for 12 hours (thawing stage), thus completing a freeze-thaw cycle.

[0081] By controlling the operating state of the electromagnetic switching valve 2015 through the controller 203, the switching between cryogenic and high-temperature media can be achieved. For example, during the freezing phase, the controller 203 controls the electromagnetic switching valve 2015 to connect the cryogenic control box 2011 to the circulation pipeline 2013, allowing the cryogenic medium to enter the circulation pipeline 2013 and cool and freeze the tailings simulation device 10. During the thawing phase, the controller 203 controls the electromagnetic switching valve 2015 to connect the high-temperature control box 2012 to the circulation pipeline 2013, allowing the high-temperature medium to enter the circulation pipeline 2013 and heat and melt the tailings simulation device 10. Through the cooperation of the circulation pump 2014 and the electromagnetic switching valve 2015, programmed control of the freeze-thaw cycle can be achieved, simulating the freezing / thawing rate, amplitude, and number of cycles.

[0082] In some embodiments, the cryogenic control box 2011 may include a dehumidification module. The dehumidification module is used to simulate the dehydration phenomenon of the tailings simulation device 10 during the freezing process. The dehumidification module may employ a condenser dehumidifier to remove moisture from the air during freezing, simulating the drying process during freezing.

[0083] In some embodiments, the high-temperature control box 2012 may include a humidification module. The humidification module is used to simulate condensation during the melting process. The humidification module may employ an ultrasonic humidifier to increase the humidity in the air during melting, simulating the condensation process.

[0084] In some embodiments, such as Figure 1 As shown, the rainfall simulation module 202 includes a water tank 2021, a rainfall infiltration layer 2022, and a solenoid valve array 2023.

[0085] The 2021 water tank is used to store water used for simulated rainfall. For example... Figure 5As shown, the rainfall infiltration layer 2022 is disposed on the top of the tailings simulation device 10, and the rainfall infiltration layer 2022 includes multiple water-permeable holes 20221. The rainfall infiltration layer 2022 can be a plate covered with water-permeable holes 20221, through which water is sprayed onto the surface of the tailings simulation device 10 to simulate the rainfall process.

[0086] The solenoid valve array 2023 includes multiple solenoid valves, each of which is connected to the controller 203 and corresponds to a water inlet 20221. Each solenoid valve in the solenoid valve array 2023 can independently control the opening and closing of the water inlet 20221 connected to it.

[0087] By controlling the opening and closing frequency and duration of each solenoid valve in the solenoid valve array 2023 through the controller 203, the water spray rate of each permeable hole 20221 can be controlled, thereby realizing complex rainfall patterns with spatial non-uniformity (such as localized torrential rain, banded rainfall) and temporal variation (such as intermittent rainfall, gradual change in rainfall intensity) at the top of the tailings simulation device 10. This programmable rainfall simulation method can simulate various complex rainfall events in nature.

[0088] In some embodiments, such as Figure 1 As shown, the bottom of the tailings simulation device 10 is provided with a leachate collection structure 304. A chemical detection module 303 is installed inside the leachate collection structure 304. The leachate collection structure 304 includes a leachate collection pipe 3041, a collection tank 3042, and a control switch 3043.

[0089] A leachate collection pipe 3041 is installed at the bottom of the tailings simulation device 10 to collect the leachate after it has been filtered through at least three layers of the structure 101. One end of the leachate collection pipe 3041 is connected to the bottom of the tailings simulation device 10, and the other end is connected to the collection pool 3042.

[0090] The collection tank 3042 is connected to the leachate collection pipe 3041 and is used to contain the leachate after it has been filtered through at least three layers of the structure 101. A pH meter 3031 and a conductivity meter 3032 are installed in the collection tank 3042 for real-time analysis and evaluation of the leachate.

[0091] A control switch 3043 is installed on the leachate collection pipe 3041 to control the discharge and collection of leachate. By controlling the switch 3043, the opening and closing of the leachate collection pipe 3041 can be controlled, thereby controlling the timing of leachate discharge and the amount collected.

[0092] The second aspect of this application provides a tailings testing method, which is applied to the tailings testing apparatus provided in the first aspect of this application, such as... Figure 6 As shown, the method includes: Step 601: At least three layers of structure are filled using layered compaction technology to prepare a tailings simulation device.

[0093] The tailings simulation device comprises at least three layers arranged vertically in sequence. Each layer is compacted in stages during filling, and after each layer reaches a certain thickness, it is compacted to the designed compaction degree using a compaction device.

[0094] Specifically, the adjacent upper layer of the structure is filled on top of the already filled layer. The same layered compaction method is used, with each layer being compacted after reaching a certain thickness until the designed height is achieved. The remaining layers are filled sequentially until all layers are completed.

[0095] In one example, the structure comprises at least three layers: a contaminant layer, a control layer, and a protected layer. During construction, the protected layer at the bottom is first compacted and filled with the protected medium. Then, the control layer is compacted and filled on top of the protected layer, filled with the control medium to be tested. Finally, the prepared contaminated tailings are filled on top of the control layer, and the contaminant layer is compacted and filled in layers.

[0096] Step 602: Install a detection device at the target location of the layer structure.

[0097] The detection device includes a mechanical detection module, a thermal-water-phase change detection module, and a chemical detection module. The thermal-water-phase change detection module includes multiple sets of detection components, which are arranged at multiple different heights within the layered structure, or multiple sets of detection components are arranged within layered structures of different heights.

[0098] During the filling process, detection components of the heat-water-phase change detection module can be embedded at the target location within the layered structure at a predetermined depth. Temperature sensors, pore water pressure gauges, and ice content detectors are placed in the same location for subsequent synchronous acquisition of temperature, pore water pressure, and ice-water phase change data. Multiple sets of detection components can be embedded at different heights within the layered structure, or embedded at different heights within the layered structure.

[0099] A laser displacement sensor is installed on top of the tailings simulation device to collect axial deformation data. A radial strain ring is fitted onto the outer wall of the tailings simulation device to collect radial deformation data.

[0100] A leachate collection structure is installed at the bottom of the tailings simulation device, and a chemical detection module is installed inside the leachate collection structure. A pH meter and a conductivity meter are placed in the collection tank.

[0101] Finally, all the cables of the detection components are led out from the reserved holes on the side wall of the tailings simulation device and connected to the acquisition device.

[0102] Step 603: Collect initial state data of the tailings simulation device through the detection device.

[0103] The initial state data includes initial mechanical response data, initial temperature data, initial pore water pressure data, initial ice-water phase transition data, and initial mechanical characteristic data.

[0104] The water level in the tailings simulation device is adjusted to the bottom of the barrier layer to simulate a specific groundwater level.

[0105] The initial height of the tailings simulation device was recorded by a laser displacement sensor. . The initial height of the tailings simulation device is used as the baseline value for subsequent calculations of frost heave and thaw settlement. Then, the initial diameter of the tailings simulation device, measured by the radial strain ring, is recorded. . The initial diameter of the tailings simulation device is used as the reference value for subsequent calculations of radial strain.

[0106] Initial temperature data is collected using temperature sensors in the detection device. These sensors are deployed along the depth profile of the tailings simulation device to determine the temperature field distribution; the initial temperature data reflects the temperature status of the tailings simulation device before the experiment begins. Initial pore water pressure data is collected at various points using pore water pressure gauges in the detection device. These gauges are embedded along the depth profile of the tailings simulation device to sense dynamic pore water pressure; the initial pore water pressure data reflects the pore water pressure status at each depth before the experiment begins. Initial ice-water phase change data is collected at various points within the tailings simulation device using an ice content detector in the detection device. This detector is embedded along the depth profile of the tailings simulation device to detect changes in the ice-water ratio; the initial ice-water phase change data reflects the ratio of unfrozen water to ice at each depth before the experiment begins.

[0107] Water samples from the collection tank were tested, and the initial pH value collected by a pH meter, the initial conductivity value collected by a conductivity meter, and the initial heavy metal concentration and initial turbidity obtained by heavy metal concentration and turbidity detection were recorded. These data reflect the chemical characteristics of the leachate before the start of the experiment.

[0108] Step 604: Apply time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads to the tailings simulation device through the environmental simulation control device.

[0109] The freeze-thaw cycle load is applied through the freeze-thaw simulation module, while the rainfall infiltration load is applied through the rainfall simulation module. The freeze-thaw cycle load and the rainfall infiltration load are superimposed over time and act together on the tailings simulation device.

[0110] In one example, the freeze-thaw simulation module includes a cryogenic control box, a high-temperature control box, a circulation pipeline, a circulation pump, and an electromagnetic switching valve. The circulation pipeline is wrapped around the outer wall of the tailings simulation device. The circulation pump drives the circulation medium to flow in the circulation pipeline. The electromagnetic switching valve selectively introduces the circulation medium from the cryogenic control box or the high-temperature control box into the circulation pipeline according to the controller's instructions, thereby applying a freeze-thaw cycle load to the tailings simulation device.

[0111] In one example, the rainfall simulation module includes a water tank, a rainfall infiltration layer, and an array of solenoid valves. The rainfall infiltration layer is located at the top of the tailings simulation device and has multiple permeable holes. Each solenoid valve in the array of solenoid valves is associated with at least one permeable hole, and the controller controls the opening and closing frequency and duration of each solenoid valve, thereby applying a rainfall infiltration load to the tailings simulation device.

[0112] In one example, the timing of the application of freeze-thaw cycle load and rainfall infiltration load is as follows: Apply freeze-thaw cycle load and run 5 complete freeze-thaw cycles, each cycle including freezing at -30°C for 12 hours and thawing at +10°C for 12 hours; while the freeze-thaw cycle is in progress, apply rainfall infiltration load at specific time points according to the experimental design, such as applying rainfall of different intensities during the freezing or thawing phase, to achieve the temporal superposition of the freeze-thaw process and the rainfall process.

[0113] Step 605: During the load application process, the current status data of the tailings simulation device is collected through the detection device.

[0114] The current state data includes current mechanical response data, current temperature data, current pore water pressure data, current ice-water phase transition data, and current chemical characteristic data.

[0115] During the combined action of freeze-thaw cycle load and rainfall infiltration load, real-time status data is collected through a detection device: the axial deformation of the tailings simulation device is measured in real time using a laser displacement sensor, and the height change is output. Record the maximum height of the tailings simulation device during the frost heave process. Stable height after melting and settling .

[0116] By using real-time measurements of the current mechanical response through a radial strain ring, the lateral deformation of the tailings simulation device can be understood, and the radial strain can be output. The expression for radial strain is: ,in This represents the change in the diameter of the tailings simulation device. This is the initial diameter of the tailings simulation device.

[0117] The current temperature data, measured in real time by a temperature sensor, is used to represent the temperature field's variation over time and depth. The temperature sensor is connected to the controller, providing a temperature reference for the entire freeze-thaw process.

[0118] The dynamic changes in pore water pressure can be obtained by measuring the current pore water pressure in real time using a pore water pressure gauge. During the freezing stage, the pore water pressure value is expected to be negative, reflecting the suction generated by water migration; during the thawing stage, the pore water pressure value is expected to be positive, reflecting the water pressure generated by the melting of ice.

[0119] Real-time measurements of the ice-water phase transition data using an ice content analyzer reveal the dynamic ratio of unfrozen water to ice, showing the migration of water towards freezing fronts and the formation and melting of ice lenses. The ice content analyzer is used to determine ice lens growth, and the ice-water phase transition data reflects the correlation between temperature changes and water migration.

[0120] By measuring the current chemical characteristics of the leachate in real time using pH and conductivity meters, changes in the chemical characteristics of the tailings simulation device can be understood. During the application of load, observe whether abnormal pulses appear in the pH and conductivity meters of the bottom collection tank, as this may indicate leakage in the control layer.

[0121] Step 606: Compare and analyze the current state data and the initial state data to establish the correlation between the response characteristics of each layer structure and the pollutant migration law under the coupled effect of freeze-thaw cycle load and rainfall infiltration load.

[0122] The migration pattern of pollutants in each layer refers to the migration characteristics exhibited by pollutants as they move from the pollutant layer through the barrier layer to the protected layer. These migration characteristics may include: changes in pollutant concentration over time, the time when pollutants first appear at the bottom of the barrier layer, the time when they first appear in the protected layer, the residence time of pollutants in each layer, the time when pollutants reach their peak concentration in the protected layer, and the peak concentration value.

[0123] The response characteristics of each structural layer refer to the physical response characteristics exhibited by each structural layer under freeze-thaw cycle loads and rainfall infiltration loads. Response characteristics can include temperature response characteristics, moisture migration response characteristics, phase change response characteristics, deformation response characteristics, and barrier response characteristics.

[0124] Temperature response characteristics can be reflected by temperature data, including the temperature change process of each layer, the time it takes for the freezing front to reach each layer, and the duration of time each layer remains frozen.

[0125] The characteristics of water migration response can be reflected by pore water pressure data, including the negative pressure value generated by each layer during the freezing stage, the positive pressure value generated during the thawing stage, and the direction of change of pore water pressure gradient.

[0126] Phase change response characteristics can be reflected by ice-water phase change data, including the formation location, formation time, growth thickness, and ablation time of ice lenses within each layer structure.

[0127] The deformation response characteristics can be reflected by the axial and radial deformation data of the tailings simulation device, including the volumetric strain of each layer, the height change during the frost heave process, the height change during the thaw settlement process, the frost heave rate, and the thaw settlement coefficient.

[0128] Barrier response characteristics can be reflected by chemical characteristic data, including the penetration time of the barrier layer to pollutants, the barrier efficiency of the barrier layer to pollutants, and the degree of degradation of the barrier performance of the barrier layer after freeze-thaw cycles.

[0129] The correlation between the response characteristics of each layer structure and the pollutant migration law refers to the influence of the above response characteristics on the pollutant migration process. The correlation may include: the correlation between temperature change and pollutant release time, the correlation between water migration direction and pollutant transport direction, the correlation between the location of ice lens formation and pollutant migration path, the correlation between the degree of structural damage of the structural layer and pollutant penetration rate, and the correlation between the performance degradation of the barrier layer and the increase of pollutant concentration, etc.

[0130] Specifically, based on temperature data collected by temperature sensors, the temperature change process of each structural layer at different depths can be determined. Based on the time it takes for the freezing front to reach each structural layer and the duration of freezing in each layer, the temperature response characteristics of each structural layer can be obtained. Based on pore water pressure data collected by pore water pressure gauges, the negative pressure value generated by each structural layer during the freezing stage and the positive pressure value generated during the thawing stage can be determined. Based on the changes in pore water pressure gradient, the water migration response characteristics of each structural layer can be obtained.

[0131] Based on the ice-water phase transition data collected by the ice content analyzer, the formation location, formation time, growth thickness, and melting time of ice lenses within each layer of the structure can be determined. The phase transition response characteristics of each layer can be obtained based on the changes in ice content.

[0132] Based on the axial deformation data collected by the laser displacement sensor and the radial deformation data collected by the radial strain ring, the volumetric strain of each layer of the structure is calculated. The deformation response characteristics of each layer can be obtained based on the height changes during freeze-thaw cycles and thaw settlement. The cumulative damage characteristics of each layer under freeze-thaw cycles can be obtained based on the freeze-thaw rate and thaw settlement coefficient.

[0133] Based on the chemical characteristic data collected by the chemical detection module, the penetration time of the barrier layer to pollutants, the adsorption or blocking efficiency of the barrier layer to pollutants, and the degree of degradation of the barrier layer's blocking performance after freeze-thaw cycles can be determined. The barrier response characteristics of the barrier layer can be obtained based on the time and concentration of pollutants reaching the protected layer.

[0134] Thus, the tailings test method provided in this application, by comparing and analyzing the current state data and the initial state data, can derive the migration patterns of pollutants from the pollutant layer through the barrier layer to the protected layer, such as concentration changes, penetration time, residence time, and peak concentration. At the same time, it can derive the temperature change characteristics, moisture migration characteristics, ice-water phase change characteristics, deformation characteristics, and barrier performance characteristics of each layer structure under the coupled effects of freeze-thaw cycles and rainfall infiltration, as well as the correlation between these characteristics and the pollutant migration patterns. Therefore, the tailings test method proposed in this application can provide experimental data and support for the stability assessment of tailings dams and the design of pollution prevention barriers.

[0135] Specifically, step 606 may include the following steps 6061 to 6066: Step 6061: Compare the chemical characteristic data with the temperature data to establish the first correlation between pollutant migration characteristics and temperature response characteristics.

[0136] The pollutant migration characteristics include the time when pollutants first appear in each layer of the structure. Temperature response characteristics include the time when the freezing front reaches each layer of the structure and the duration of freezing in each layer. By plotting temperature data distribution curves along depth at different time points, the temperature variation with time and depth can be determined. By comparing the time of the first appearance of pollutants with the temperature variation process, a correlation can be established between the two.

[0137] Step 6062: Compare the chemical characteristic data with the pore water pressure data to establish a second correlation between pollutant migration characteristics and water migration response characteristics.

[0138] Pollutant migration characteristics also include the movement paths of pollutants between different structural layers. Moisture migration response characteristics include the direction of change in pore water pressure gradient. Pore water pressure gauges are used to collect dynamic changes in pore water pressure, which can determine the direction of change in pore water pressure data. By comparing the pollutant movement paths with the direction of change in pore water pressure data, a correlation can be established between the two.

[0139] Step 6063: Compare the chemical characteristic data with the ice-water phase change data to establish a third correlation between pollutant migration characteristics and phase change response characteristics.

[0140] Pollutant migration characteristics can also include the location where pollutants first appear in each layer of the structure. Phase change response characteristics include the formation location of ice lenses. An ice content analyzer is used to collect dynamic data on the ratio of unfrozen water to ice, which can determine the formation location of ice lenses. By comparing the location where pollutants first appear with the formation location of ice lenses, a correspondence between the two can be established.

[0141] Step 6064: Compare the chemical characteristic data with the axial deformation data and radial deformation data to establish a fourth correlation between pollutant migration characteristics and deformation response characteristics.

[0142] Contaminant migration characteristics can also include the time it takes for contaminants to penetrate each layer of the structure. Deformation response characteristics include the volumetric strain of each layer. A laser displacement sensor is used to collect axial deformation data, and a radial strain ring is used to collect radial deformation data. By combining the axial and radial deformation data, volumetric strain can be calculated. By comparing the contaminant penetration time with the change in volumetric strain, a correlation between the two can be established.

[0143] Step 6065: Compare the chemical characteristic data of the barrier layer with the ice-water phase transition data within the barrier layer to establish the fifth correlation between the pollutant migration characteristics of the barrier layer and the phase transition response characteristics of the barrier layer.

[0144] Pollutant migration characteristics also include the time it takes for pollutants to penetrate the barrier layer and the peak concentration reaching the protected layer. The phase transition response characteristics of the barrier layer include the formation location of ice lenses within the barrier layer. By comparing the formation location of ice lenses within the barrier layer with the time it takes for pollutants to penetrate the barrier layer and the peak concentration reaching the protected layer, a correlation can be established between the two.

[0145] Step 6066: Based on the first to fifth correlations, construct the correlation between the response characteristics of each layer structure and the pollutant migration pattern. Combining the above five sets of correlations, establish an overall correlation model between the response characteristics of each layer structure and the pollutant migration pattern. Based on the temperature response characteristics, moisture migration response characteristics, phase change response characteristics, deformation response characteristics, and barrier response characteristics of each layer structure, determine the migration pattern of pollutants under the coupled effects of freeze-thaw cycles and rainfall infiltration.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A tailings test system, characterized in that, include: Tailings simulation device, comprising at least three layers arranged vertically in sequence; An environmental simulation control device is used to apply time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads to the tailings simulation device. The detection device includes a mechanical detection module, a thermal-water-phase change detection module, and a chemical detection module. The mechanical detection module is located outside the tailings simulation device and is used to collect the mechanical response data of the tailings simulation device. The thermal-water-phase change detection module is embedded in the layered structure and is used to collect the temperature data, pore water pressure data, and ice-water phase change data of the layered structure under the action of the freeze-thaw cycle load and the rainfall infiltration load. The chemical detection module is located at the bottom of the tailings simulation device and is used to collect the chemical characteristic data of the leachate after filtration through the at least three-layer structure.

2. The tailings test system according to claim 1, characterized in that, The thermal-water-phase change detection module includes multiple sets of detection components, which are arranged at multiple different heights within the layer structure, or the multiple sets of detection components are arranged within the layer structure at different heights.

3. The tailings test system according to claim 2, characterized in that, Each group of detection components includes: Temperature sensor, used to collect temperature data; A pore water pressure gauge is used to collect pore water pressure data. An ice content analyzer is used to collect ice-water phase change data; The temperature data, pore water pressure data, and ice-water phase change data are used to establish a quantitative relationship model of water migration-phase change-pressure response driven by temperature.

4. The tailings test system according to claim 3, characterized in that, The temperature sensor, the pore water pressure gauge, and the ice content detector are embedded at the same location within the layer structure to synchronously collect the temperature data, the pore water pressure data, and the ice-water phase change data at that location.

5. The tailings test system according to claim 1, characterized in that, At least three layers arranged vertically in sequence include: A contaminant layer, located at the top of the tailings simulation device, is used to contain contaminants; A barrier control layer, located below the contaminant layer, is used to contain the barrier control medium to be tested; The protected layer, located below the barrier layer, is used to contain the protected medium.

6. The tailings test system according to claim 1, characterized in that, The mechanical detection module includes: A laser displacement sensor is installed on the top of the tailings simulation device to collect axial deformation data of the tailings simulation device; A radial strain ring is fitted onto the outer wall of the tailings simulation device to collect radial deformation data of the tailings simulation device.

7. The tailings test system according to any one of claims 1 to 6, characterized in that, The chemical detection module includes: A pH meter is installed at the bottom of the tailings simulation device to collect the acidity and alkalinity data of the leachate. An electrical conductivity meter is installed at the bottom of the tailings simulation device to collect data on the total ion concentration of the leachate.

8. The tailings test system according to any one of claims 1 to 6, characterized in that, The environmental simulation control device includes a controller and a rainfall simulation module, the rainfall simulation module comprising: Water tank; A rainfall infiltration layer is provided on top of the tailings simulation device, and the rainfall infiltration layer includes multiple water-permeable holes; An array of solenoid valves, each of which is connected to the controller and corresponds to one of the water inlets.

9. The tailings test system according to any one of claims 1 to 6, characterized in that, The environmental simulation control device further includes a controller and a freeze-thaw simulation module, the freeze-thaw simulation module comprising: The low-temperature control box and the high-temperature control box store circulating media at different temperatures respectively; A circulation pipeline, connected to the tailings simulation device, is used to transport the circulating medium to the layered structure; A circulating pump, installed in the circulating pipeline and connected to the controller, is used to drive the flow of the circulating medium; An electromagnetic switching valve is installed in the circulation pipeline and connected to the controller, for selectively introducing the circulating medium from the low-temperature control box or the high-temperature control box into the circulation pipeline.

10. A tailings testing method, characterized in that, The tailings testing method is applied to the tailings testing system as described in any one of claims 1 to 9, and the tailings testing method includes: A tailings simulation device was prepared by using a layered compaction technique to fill at least three layers of the structure. A detection device is installed at the target location of the layer structure; The initial state data of the tailings simulation device is collected by the detection device. The initial state data includes initial mechanical response data, initial temperature data, initial pore water pressure data, initial ice-water phase transition data, and initial chemical characteristic data. The tailings simulation device is subjected to time-series superimposed freeze-thaw cycle loads and rainfall infiltration loads through an environmental simulation control device. During the load application process, the current state data of the tailings simulation device is collected by the detection device. The current state data includes current mechanical response data, current temperature data, current pore water pressure data, current ice-water phase transition data, and current chemical characteristic data. By comparing and analyzing the current state data and the initial state data, the correlation between the response characteristics of each layer structure and the pollutant migration law under the coupled effect of freeze-thaw cycle load and rainfall infiltration load is established.

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