Simulation test device for underground coal mining surface subsidence accumulated water in high-water-level area

Abstract

The invention discloses a simulation test device for underground coal mining surface subsidence accumulated water in a high phreatic water level area, and relates to the technical field of simulation test equipment for underground coal mining. A lifting rod of a lifting module is adjusted to move up and down to drive a coal seam top plate to move up and down, and different surface subsidence processes caused by coal mining can be simulated; different surface subsidence ponding processes can be simulated through the stratum simulation assembly, the surface water simulation assembly and the underground water simulation assembly; based on an airflow generator, an illumination generator, a top cover, an air inlet valve, an exhaust valve and the like, the influence of changes of wind power, illumination, aerobic / anaerobic and the like on the surface subsidence ponding environment can be simulated. According to the invention, different subsidence ponding processes of coal mining in the high-water-level coal mine area are simulated indoors, the problem that in-situ sampling is difficult and inaccurate when related researches of the high-water-level coal mining subsidence area are carried out is effectively solved, the simulation test device is simple to operate, in-situ conditions are effectively restored, and a new method for carrying out related researches is provided.

Description

Technical Field

[0001] The invention relates to the technical field of underground coal mining simulation test equipment, in particular to an underground coal mining surface subsidence water accumulation simulation test device in a high water level area. Background Art

[0002] In high-water-level coal mining areas, due to the flat terrain and high underground water level, underground coal mining destroys the stratum structure, and the surface subsidence area formed will accumulate water over a large area, forming a coal mining subsidence water accumulation area. The coal mining subsidence water accumulation area has significantly changed the regional surface morphology, changing the terrestrial farmland ecosystem into an aquatic ecosystem, and has a severe impact on the regional geology, hydrology, and ecological environment. The study of the soil subsidence and water accumulation process and the environmental change characteristics of surface water and shallow groundwater after stabilization, and the impact characteristics of different water accumulation depths and different water accumulation times on the soil environment have important indicative significance and application value for the ecological environment protection and green mine construction in high-water-level coal mining areas.

[0003] Previous related studies were mostly based on in-situ sampling, but the field conditions are complex and changeable, sampling is difficult and costly. On the other hand, the surface subsidence and water accumulation process is affected by coal mining activities, regional hydrological conditions, etc., and the change process of subsidence and water accumulation is complex. Based on the research scheme of in-situ sampling, it is difficult to accurately collect soil, surface water, and groundwater samples of different processes such as surface collapse and water accumulation, and it is difficult to accurately reveal the environmental change characteristics of soil, surface water, and shallow groundwater during coal mining subsidence and water accumulation. The simulation test method simulates the evolution process of subsidence and water accumulation based on the research object, research process, and research purpose, and has the advantages of strong visualization, short cycle, and high flexibility. Therefore, in order to better carry out the study of the water and soil environment of the subsidence and water accumulation area in the high groundwater level coal mining area, a surface subsidence and water accumulation simulation test device is urgently needed. However, the coal mining subsidence and water accumulation simulation test device has not been systematically studied, and it is still impossible to simulate the coal mining subsidence and water accumulation process indoors. Summary of the invention

[0004] The invention provides a simulation test device for surface subsidence and water accumulation in underground coal mining in areas with high water levels, which solves the technical problem that there is currently no simulation device related to the evolution process of coal mining subsidence and water accumulation.

[0005] In order to solve the above technical problems, the present invention provides a surface subsidence and water accumulation simulation test device for underground coal mining in high water level areas, comprising a simulation test box made of transparent material, a subsidence simulation component, a formation simulation component, a surface water simulation component, a groundwater simulation component, an environmental parameter control component and an observation sampling component; the subsidence simulation component includes a coal seam roof, and the simulation test box is divided into an upper and lower layer by the coal seam roof, the upper layer is a subsidence simulation area, and the lower layer is a coal seam simulation area.

[0006] In some embodiments, the subsidence simulation component includes a plurality of lifting modules and a plurality of coal seam roof plates; the lifting module includes a lifting controller, a lifting base, and a lifting rod; the lifting base is disposed at the bottom of the simulation test chamber, the lifting rod is movably installed above the lifting base, and the lifting controller drives the lifting rod to move up and down; the coal seam roof plates are respectively disposed on the corresponding lifting rods, a subsidence water accumulation simulation area is above the coal seam roof plates, and the coal seam roof plates can move vertically up and down; the total number of the coal seam roof plates matches the number of the lifting modules, and each of the coal seam roof plates divides the subsidence water accumulation simulation area into several subsidence segments.

[0007] In some embodiments, the formation simulation component includes a clay layer, a phreatic layer, a vadose zone soil layer, and a soil layer from bottom to top; the thicknesses of the clay layer, the phreatic layer, the vadose zone soil layer, and the soil layer can be arranged according to the test requirements.

[0008] In some embodiments, the surface water simulation component includes a water inlet tank, a water inlet pump, a water inlet pipe, and a water distributor; the water inlet tank is disposed outside the simulation test chamber, the suction port of the water inlet pump is connected to the water inlet tank, and the water distributor is connected to the water inlet pump through the water inlet pipe; a ball valve is provided at the water inlet end of the water distributor, and the ball valve can control the water inflow rate to simulate different rainfall intensities.

[0009] In some embodiments, the groundwater simulation component includes a high-level water tank, a water inlet hole, a water level regulating valve, a return water tank, a return water pump, and a return water pipe; the high-level water tank, the return water tank, the return water pipe, and the water level regulating valve are disposed outside the simulation test chamber, the water inlet hole is disposed on the inner wall of the simulation test chamber, the return water pump is disposed above the return water tank, and the outlet of the return water pump is connected to the high-level water tank through the return water pipe; the water level in the high-level water tank can be set according to the test requirements to simulate different lateral recharge heads of the aquifer; the water in the high-level water tank enters the unconfined aquifer through the water inlet hole; the plurality of water level regulating valves are vertically and equidistantly installed in sequence, when the regulating valves at different positions are opened and closed, the water in the unconfined aquifer can overflow from different heights to simulate different unconfined aquifer water levels, and the water levels of the high-level water tank and the unconfined aquifer can be measured by the water tank scale lines and the test chamber scale lines respectively; the water overflowing from the water level regulating valve enters the return water tank, and the return water pump sends the water back to the high-level water tank through the return water pipe.

[0010] In some embodiments, the environmental parameter regulation component includes an air flow generator, a light generator, a top cover, an air inlet valve, and an air outlet valve; the air flow generator is disposed in the simulation test chamber, the light generator is disposed above the interior of the simulation test chamber, the air inlet valve and the air outlet valve are respectively disposed on both sides of the simulation test chamber; the top cover is detachably installed above the simulation test chamber and can completely seal the simulation test chamber.

[0011] In some embodiments, the observation and sampling assembly includes a plurality of sampling valves, a plurality of test chamber scale lines, a plurality of laser displacement sensors, and a plurality of multi-parameter monitoring electrodes. The plurality of observation and sampling assemblies correspond to the coal seam roof in sequence; the sampling valves and the test chamber scale lines are arranged on the side wall of the simulation test chamber, and the plurality of sampling valves are vertically installed at equal intervals in sequence; the laser displacement sensors are arranged on the inner wall of the simulation test chamber, and the multi-parameter monitoring electrodes are arranged in the soil layer; the sampling valves can collect surface water, groundwater, and soil samples at different heights; the test chamber scale lines can measure the water levels of surface water and groundwater; the laser displacement sensors can measure the surface settlement in real time; the multi-parameter monitoring electrodes can measure the relevant indexes in the soil and water in real time.

[0012] The present invention also provides a simulation test method for surface subsidence and water accumulation in underground coal mining in high water table areas, which specifically includes the following steps:

[0013] Step S1: Control all lifting modules to rise to the highest position through the lifting controller;

[0014] Step S2: Fill the test stratum structure above the coal seam roof;

[0015] Step S3: Operate the lifting controller to control the downward movement of each lifting module to simulate the progressive subsidence process in different areas, including subsidence in different areas at different times and different subsidence depths in different areas;

[0016] Step S4: Control the opening and closing of the electromagnetic ball valve on the water inlet pipe of the water distributor according to the test requirements to simulate different rainfall ranges and rainfall intensities;

[0017] Step S5: Control the opening and closing of the water level regulating valve to simulate the water level height of the phreatic aquifer;

[0018] Step S6: When the downward movement of the lifting module drives the surface to subside to form a surface subsidence area, the rainwater and the water in the phreatic aquifer can converge in the surface subsidence area to form a subsidence water accumulation area;

[0019] Step S7: Collect soil samples and water samples at different subsidence stages through the sampling valves, and combine with the observation assembly to record the surface settlement, the water levels of surface water and groundwater, and the relevant indexes in the soil and water during the process of subsidence water accumulation;

[0020] Step S8: Regulate the air flow generator, the light generator, the top cover, the air inlet valve, and the exhaust valve to simulate the influence of environmental condition changes on the subsidence water accumulation area.

[0021] In some embodiments, in step S6:

[0022] When the downward movement of the coal seam roof drives the surface to subside, the stratum structure is damaged, and vertical and lateral water flow channels are naturally formed. The surface water and the underground phreatic water are interconnected, and the groundwater enters the subsidence area through the water flow channels.

[0023] In some embodiments, step S8 specifically includes:

[0024] Replacing the gas environment in the tank through the exhaust valve and the intake valve, and cooperating with the top cover seal to form an anaerobic environment;

[0025] Simulating the change of wind force on the water surface through the air flow generator;

[0026] Adjusting the light intensity to 0 - 150000 lux through the light generator.

[0027] Compared with the related technology, a simulation test device for surface subsidence and water accumulation in underground coal mining in high water table areas provided by the present invention has the following beneficial effects:

[0028] The present invention provides a simulation test device for surface subsidence and water accumulation in underground coal mining in high water table areas. By adjusting the up and down movement of the lifting rod of the lifting module to drive the up and down movement of the coal seam roof, different surface subsidence processes caused by coal mining can be simulated; different surface subsidence and water accumulation processes can be simulated through the formation simulation component, surface water simulation component, and groundwater simulation component; based on the air flow generator, light generator, top cover, intake valve, and exhaust valve, etc., the effects of wind disturbance, light, aerobic / anaerobic, etc. changes on the surface subsidence and water accumulation environment can be simulated; based on the observation and sampling component, the subsidence and water accumulation process and the changes of relevant indexes in the soil and water after reaching the stable state can be monitored in real time. Thus, the present invention realizes the simulation of different subsidence and water accumulation processes in coal mining in high water table coal mining areas by coupling the geomechanical field (soil subsidence), seepage field (water accumulation process), and environmental field (wind / light / oxygen interaction) in the laboratory, and effectively solves the problems of difficult and inaccurate in-situ sampling when carrying out relevant research on high water table coal mining subsidence areas. The device is simple to operate, effectively restores the in-situ conditions, and provides a new method for carrying out relevant research. Description of the Drawings

[0029] Figure 1 It is a three-dimensional structure schematic diagram of the present invention;

[0030] Figure 2 It is a three-dimensional structure schematic diagram of the present invention without the formation simulation component;

[0031] Figure 3 It is a schematic diagram of the top cover structure of the present invention;

[0032] Figure 4 For the present invention Figure 1 Partial enlarged view at A in the present invention.

[0033] Reference numerals in the figure: 1, simulation test chamber; 2, top cover; 3, coal seam roof; 4, nut; 5, bolt; 6, lifting module; 7, water inlet water tank; 8, water inlet pump; 9, water inlet pipe; 10, electromagnetic ball valve; 11, water distributor; 12, high-level water tank; 13, water level regulating valve; 14, return water tank; 15, return water pump; 16, return water pipe; 17, clay layer; 18, phreatic aquifer; 19, vadose zone soil layer; 20, soil layer; 21, axial flow fan; 22, intake valve; 23, exhaust valve; 24, lamp tube; 25, laser displacement sensor; 26, sampling valve; 27, test chamber scale line; 28, water tank scale line; 29, water inlet hole; 30, multi-parameter monitoring electrode. Detailed implementation manners

[0034] Example 1, as Figures 1 to 4 shown, this example provides a simulation test device for surface subsidence and water accumulation in underground coal mining in high phreatic level areas. Figure 1 It is a schematic three-dimensional structure diagram of the present invention. For the convenience of observing the internal structure, the front side wall of the simulation test device is shown in a partial sectional view. This example mainly includes a simulation test chamber 1 made of transparent organic glass, a subsidence simulation component, a formation simulation component, a surface water simulation component, a groundwater simulation component, an environmental parameter regulation component, and an observation and sampling component.

[0035] The subsidence simulation component includes a lifting module 6 and a coal seam roof 3. The inside of the simulation test chamber 1 is divided into upper and lower layers by the coal seam roof 3. The upper layer is the subsidence simulation area, and the lower layer is the coal seam simulation area; the lifting module 6 includes a lifting controller (not marked in the figure), a lifting base, and a lifting rod; the lifting base is arranged at the bottom of the simulation test chamber 1, and the lifting rod is movably installed above the lifting base; each lifting module 6 can be independently controlled by the lifting controller, and the vertical movement distance can be accurately controlled.

[0036] The coal seam roof 3 is arranged on the corresponding lifting rod. The total number of the coal seam roofs 3 matches the number of the lifting modules 6. Each coal seam roof 3 divides the surface subsidence simulation area into several subsidence segments.

[0037] By controlling different lifting modules 6 to drive the corresponding coal seam roofs 3 to move downward, the progressive subsidence process in different regions can be simulated, including subsidence in different regions at different times and different subsidence depths in different regions.

[0038] The formation simulation component includes, from bottom to top, a clay layer 17, a phreatic aquifer 18, a vadose zone soil layer 19, and a soil layer 20. The thickness of each layer can be arranged according to the test requirements.

[0039] The surface water simulation component includes a water inlet tank 7, a water inlet pump 8, a water inlet pipe 9, an electromagnetic ball valve 10, and a water distributor 11; the water inlet tank 7 is arranged outside the simulation test box 1, the water inlet pump 8 is arranged on the upper side of the water inlet tank 7, the water inlet pipe 9 is arranged on the outer and inner side walls of the simulation test box 1, the water distributor 11 is arranged on the water inlet pipe 9, the suction port of the water inlet pump 8 is connected to the water inlet tank 7, and the water distributor 11 is connected to the water inlet pump 8 through the water inlet pipe 9;

[0040] The water inlet pump 8 can extract the water in the water inlet tank 7, send it to the water distributor 11 through the water inlet pipe 9, and each water distributor 11 can independently control the water outlet through the electromagnetic ball valve 10;

[0041] The water distributor 11 can sprinkle water evenly to simulate rainfall. An electromagnetic ball valve 10 is arranged on the water inlet pipe of the water distributor 11, and the electromagnetic ball valve 10 can control the water inflow to simulate different rainfall intensities;

[0042] By controlling the opening and closing of the electromagnetic ball valves 10 in different areas, it can simulate that the rainwater in different areas directly enters or converges into the surface subsidence area through runoff.

[0043] The groundwater simulation component includes a high-level water tank 12, a water inlet hole 29, multiple water level regulating valves 13, a return water tank 14, a return water pump 15, and a return water pipe 16; the high-level water tank 12, the return water tank 14, the return water pipe 16, and the water level regulating valves 13 are arranged outside the simulation test box, the water inlet hole 29 is arranged inside the simulation test box, and the return water pump 15 is arranged on the upper side of the return water tank 14;

[0044] The water level of the high-level water tank 12 can be set according to the test requirements to simulate different lateral recharge water heads of the aquifer;

[0045] The water in the high-level water tank 12 enters the phreatic aquifer 18 through the water inlet hole 29;

[0046] The water level regulating valves 13 are installed vertically and there are multiple of them. By controlling the opening of the water level regulating valves 13 at different positions, the water in the phreatic aquifer 18 can overflow to simulate different phreatic water levels. The water levels of the high-level water tank 14 and the phreatic aquifer 18 can be measured by the water tank scale line 28 and the test box scale line 27 respectively;

[0047] The water overflowing from the water level regulating valves 13 enters the return water tank 14, and the return water pump 15 sends the water back to the high-level water tank 12 through the return water pipe 16;

[0048] Thus, different lateral recharge water heads and phreatic aquifers with different water levels can be simulated.

[0049] When the coal seam roof 3 moves downward driven by the lifting module 6, it can simulate the progressive subsidence process in different regions (subsidence in different regions at different times and different subsidence depths in different regions); by controlling the surface water simulation component, it can simulate the process of surface water gathering in the subsidence area; when the strata structure is damaged during subsidence, vertical and lateral water flow channels are formed, and the surface water is interconnected with the groundwater in the phreatic aquifer. The groundwater enters the subsidence area through the water flow channels, simulating the formation process of the subsidence water accumulation area formed by the inflow of groundwater; after the subsidence water accumulation reaches a stable state, according to the progressive subsidence process in different regions, it is possible to simulate subsidence water accumulation areas with different formation times and subsidence water accumulation areas with different water depths.

[0050] The environmental parameter regulation component includes an air flow generator, a light generator, a top cover 2, an intake valve 22, and an exhaust valve 23;

[0051] The air flow generator is arranged in the simulation test chamber 1, and the light generator is arranged above the interior of the simulation test chamber 1. The air flow generator and the light generator are respectively electrically connected to an electric control device (not marked in the figure);

[0052] In this embodiment, the air flow generator and the light generator respectively use an axial flow fan 21 and a lamp tube 24. The axial flow fan 21 and the lamp tube 24 are both independently controlled by the electric control device. Two axial flow fans 21 are provided on the left inner wall of the simulation test chamber 1, and lamp tubes 24 are provided on the front and rear inner walls. Each axial flow fan 21 and lamp tube 24 can be independently controlled to open and close;

[0053] The top cover 2 is detachably installed on the top of the simulation test chamber 1. The top cover 2 and the simulation test chamber 1 are provided with protruding mounting holes. After the top cover 2 is tightened, it is pressed by bolts 5 and nuts 4 to achieve a sealing effect;

[0054] The intake valve 22 and the exhaust valve 23 are both arranged on the side wall of the simulation test chamber 1. By connecting an external air extraction pump (not marked in the figure) to the exhaust valve 23, the air in the simulation test chamber 1 can be pumped out, and nitrogen can be filled through the intake valve 22 to create an anaerobic / anoxic environment.

[0055] The observation and sampling component includes a plurality of sampling valves 26, a test chamber scale line 27, a laser displacement sensor 25, and a multi-parameter monitoring electrode 30;

[0056] A plurality of sampling valves 26 and the test chamber scale line 27 are arranged on the side wall of the simulation test chamber 1, corresponding to the coal seam roof 3. The plurality of sampling valves 26 are vertically installed at equal intervals in sequence;

[0057] The laser displacement sensor 25 is arranged on the inner wall of the simulation test chamber 1, and the multi-parameter monitoring electrode 30 is arranged in the soil layer. The number of multi-parameter monitoring electrodes 30 corresponds to that of the coal seam roof 3;

[0058] The sampling valve 26 can collect surface water, groundwater and soil samples at different heights, and the scale line 27 of the test box can measure the water levels of surface water and groundwater;

[0059] The laser displacement sensor 25 can measure the surface subsidence in real time;

[0060] The multi-parameter monitoring electrode 30 can measure indicators such as soil pH, redox potential, dissolved oxygen, temperature, and conductivity in water in real time;

[0061] Thus, it is possible to monitor relevant indicators during the process of subsidence and water accumulation and after the subsidence and water accumulation reach a stable state.

[0062] Working principle:

[0063] The working principle of the present invention is divided into two parts: (1) Subsidence and water accumulation simulation; (2) Simulation test.

[0064] (1) Subsidence and water accumulation simulation

[0065] First, set the simulation conditions:

[0066] According to the actual in-situ situation and test requirements, a clay layer 17, a phreatic aquifer 18, a vadose zone soil layer 19, and a soil layer 20 are arranged on the coal seam roof 3 to simulate the in-situ soil layer structure; multi-parameter monitoring electrodes 30 are installed in the soil layer, and the number of multi-parameter monitoring electrodes 30 is the same as the number of coal seam roofs 3; the water volumes of the high-level water tank 12 and the inlet water tank 7 are replenished, and the opening position of the water level regulating valve 13 is controlled to simulate the lateral recharge head and the phreatic aquifer water level of the phreatic aquifer. The phreatic aquifer water level and the high-level water tank water level values are measured through the scale line 27 of the test box and the scale line 28 of the water tank.

[0067] Control all lifting modules 6 to be in the maximum lifting position to simulate the initial state where the surface is not subsided.

[0068] According to the test requirements, each coal seam roof 3 can be independently controlled to move downward by the lifting controller, and the downward movement distance can be measured from the scale line 27 of the test box to simulate the progressive subsidence process in different regions (subsidence in different regions at different times, different subsidence depths in different regions).

[0069] When the coal seam roof 3 moves downward to drive the formation subsidence, according to the test requirements, the electromagnetic ball valves 10 on the water inlet pipes of different water distributors 11 are opened, and the opening angle of the electromagnetic ball valves 10 is adjusted to simulate different rainfall regions and rainfall intensities. The rainwater in different regions directly enters or is collected into the surface subsidence area through runoff; the formation structure is damaged, forming vertical and lateral water flow channels, and the surface water is interconnected with the underground phreatic aquifer water. The groundwater is collected into the surface subsidence area through the water flow channels, forming a subsidence and water accumulation area. Thus, subsidence and water accumulation areas with different formation times and different water depths are simulated.

[0070] The scale line 27 of the test chamber can measure the water depth of surface water and groundwater. The laser displacement sensor 25 can measure the surface settlement in real time. The multi-parameter monitoring electrode 30 can measure in real time indicators such as soil pH, redox potential, dissolved oxygen, temperature, and conductivity in the water during the process of subsidence and water accumulation.

[0071] (2) Simulation test

[0072] According to the test requirements, after the subsidence and water accumulation reach a stable state, the axial flow fan 21 can simulate the change of water surface wind force to simulate the impact of wind disturbance on the environment of different subsidence and water accumulation areas.

[0073] The top cover 2 is tightly covered with the simulation test chamber 1 through bolts 5 and nuts 4. The exhaust valve 23 is connected to a vacuum pump (not marked in the figure), and the intake valve 22 is connected to a nitrogen tank (not marked in the figure). After exhausting the air in the test chamber through the exhaust valve 23, nitrogen is filled to simulate the impact of anoxic / anaerobic environment on the environment of the surface subsidence and water accumulation area.

[0074] Control the opening and closing number of the control lamp tube 24 to simulate the impact of the change of light intensity on the environment of the surface subsidence and water accumulation area.

[0075] The multi-parameter monitoring electrode 30 can measure in real time indicators such as soil pH, redox potential, dissolved oxygen, temperature, and conductivity in the water of the subsidence and water accumulation area.

[0076] During the simulation test, surface water, groundwater and sediment samples at different positions can be collected through the sampling valve 26 to carry out relevant experimental studies.

Claims

1. Simulation test device for surface subsidence water accumulation in underground coal mining in high phreatic water level areas, characterized in that: It includes a simulation test chamber made of a transparent material, and a subsidence simulation component, a formation simulation component, a surface water simulation component, a groundwater simulation component, an environmental parameter regulation component, and an observation and sampling component arranged on the simulation test chamber; the subsidence simulation component includes a coal seam roof, and the inside of the simulation test chamber is divided into upper and lower layers by the coal seam roof. The upper layer is a subsidence simulation area, and the lower layer is a coal seam simulation area.

2. The simulation test device for surface subsidence water accumulation in underground coal mining in high phreatic level areas according to claim 1, characterized in that, The subsidence simulation component further includes a lifting module; the lifting module includes a lifting controller, a lifting base, and a lifting rod. The lifting base is arranged at the bottom of the simulation test chamber, the lifting rod is movably installed above the lifting base, and the lifting controller drives the lifting rod to move up and down; the coal seam roofs are respectively arranged on the corresponding lifting rods; the total number of the coal seam roofs matches the number of the lifting modules, and each of the coal seam roofs divides the subsidence simulation area into several subsidence segments.

3. The simulation test device for surface subsidence water accumulation in underground coal mining in high water table areas according to claim 1, characterized in that, The formation simulation component includes a clay layer, a phreatic layer, a vadose zone soil layer, and a soil layer from bottom to top.

4. The simulation test device for surface subsidence water accumulation in underground coal mining in high phreatic level areas according to claim 1, characterized in that, The surface water simulation component includes a water inlet water tank, a water inlet pump, a water inlet pipe, and a water distributor; the water inlet water tank is arranged outside the simulation test chamber, the water inlet pump is arranged on the upper side of the water inlet water tank, the suction port of the water inlet pump is connected to the water inlet water tank, and the water distributor is connected to the water inlet pump through the water inlet pipe; an electromagnetic ball valve is arranged on the water inlet pipe of the water distributor, and the electromagnetic ball valve can control the water inflow rate to simulate different rainfall intensities.

5. The simulation test device for surface subsidence water accumulation in underground coal mining in high phreatic level areas according to claim 1, characterized in that, The groundwater simulation component includes a high-level water tank, a water inlet hole, a plurality of water level regulating valves, a return water tank, a return water pump, and a return water pipe; the high-level water tank, the return water tank, the return water pipe, and the water level regulating valves are arranged outside the simulation test chamber, the water inlet hole is arranged on the inner wall of the simulation test chamber, the return water pump is arranged on the upper side of the return water tank, and the outlet of the return water pump is connected to the high-level water tank through the return water pipe; the water level in the high-level water tank can be set according to the test requirements to simulate different lateral recharge water heads of aquifers; the water in the high-level water tank enters the phreatic layer through the water inlet hole; the plurality of water level regulating valves are vertically installed at equal intervals in sequence. When the regulating valves at different positions are opened and closed, the water in the phreatic layer can overflow from different heights to simulate different phreatic layer water levels. The water levels of the high-level water tank and the phreatic layer can be measured by the scale lines of the water tank and the test chamber respectively; the water overflowing from the water level regulating valve enters the return water tank, and the return water pump sends the water back to the high-level water tank through the return water pipe.

6. The simulation test device for surface subsidence water accumulation in underground coal mining in high water table areas according to claim 1, characterized in that, The environmental parameter regulation component includes an air flow generator, a light generator, a top cover, an air inlet valve, and an air outlet valve; the air flow generator is arranged in the simulation test chamber, the light generator is arranged above the interior of the simulation test chamber, the air inlet valve and the air outlet valve are respectively arranged on both sides of the simulation test chamber; the top cover is detachably installed above the simulation test chamber and can completely seal the simulation test chamber.

7. The simulation test device for surface subsidence water accumulation in underground coal mining in high phreatic level areas according to claim 1, characterized in that The observation and sampling assembly includes a plurality of sampling valves, a plurality of test chamber graduation lines, a plurality of laser displacement sensors, and a plurality of multi-parameter monitoring electrodes. The plurality of observation and sampling assemblies correspond to the coal seam roof in sequence; the sampling valves and graduation lines are arranged on the side wall of the simulation test chamber, and the plurality of sampling valves are vertically installed at equal intervals in sequence; the laser displacement sensors are arranged on the inner wall of the simulation test chamber, and the multi-parameter monitoring electrodes are arranged in the soil layer.

8. A method of conducting an experiment using the surface subsidence water accumulation simulation test device for underground coal mining in high phreatic level areas according to any one of claims 1-7, characterized in that, It includes the following steps: Step S1: Control all lifting modules to rise to the highest position through the lifting controller; Step S2: Fill the test formation structure above the coal seam roof; Step S3: Operate the lifting controller to control each lifting module to move downward to simulate the progressive subsidence process in different areas, including subsidence in different areas at different times and different subsidence depths in different areas; Step S4: Control the opening and closing of the electromagnetic ball valve on the water inlet pipe of the water distributor according to the test requirements to simulate different rainfall ranges and rainfall intensities; Step S5: Control the opening and closing of the water level regulating valve to simulate the water level height of the phreatic aquifer; Step S6: When the lifting module moves downward to drive the ground surface to subside to form a ground surface subsidence area, the rainwater and the water in the phreatic aquifer gather in the ground surface subsidence area to form a subsidence water accumulation area; Step S7: Collect soil samples and water samples at different subsidence stages through the sampling valves, and combine with the observation assembly to record the ground surface settlement amount, the water levels of surface water and groundwater, and the relevant indexes in the soil and water during the process of water accumulation in the subsidence area; Step S8: Regulate the air flow generator, light generator, top cover, intake valve, and exhaust valve to simulate the influence of environmental condition changes on the subsidence water accumulation area.

9. The simulation test method for surface subsidence water accumulation in underground coal mining in high phreatic level areas according to claim 8, characterized in that, In the said Step S6: When the coal seam roof moves downward to drive the ground surface to subside, the formation structure is damaged, and vertical and lateral water flow channels are naturally formed. The surface water is interconnected with the underground phreatic aquifer water, and the groundwater enters the subsidence area through the water flow channels.

10. The simulation test method for surface subsidence water accumulation in underground coal mining in high water table areas according to claim 8, characterized in that, The said Step S8 specifically includes: Replace the gas environment in the box through the exhaust valve and intake valve, and cooperate with the top cover seal to form an anaerobic environment; Simulate the change of water surface wind force through the air flow generator; Adjust the light intensity to 0 - 150000 lux through the light generator.

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