Simulation test device and method for water inrush of fault subsidence structure induced by mine water recharge

Abstract

The invention discloses a simulation test device and method for water inrush of a fault subsidence structure induced by mine water recharge, and relates to the technical field of mine water disaster prevention and control, the device comprises a mine water supply and regulation system, a water inrush simulation box and a real-time monitoring system, and an adjustable structure simulation system is arranged in the water inrush simulation box. Fault or collapse column models with different parameters can be constructed, confining pressure and temperature are applied through a rubber sleeve and a temperature control jacket, a deep stratum environment is simulated, a real-time monitoring system synchronously collects multi-field coupling data, and real-time judgment and early warning of four levels of risks of stability, evolution, criticality and water inrush are achieved based on grey correlation analysis and an improved Bayesian judgment algorithm. When the risk is upgraded, the system automatically regulates and controls the recharge parameters in a linkage mode, safe disposal is achieved, the whole process of activation water inrush of the structure induced by deep well recharge can be controllably reproduced, and effective indoor test means and data support are provided for risk evaluation and prevention and control strategy formulation of a recharge project.

Description

Technical Field

[0001] This invention relates to the field of mine water hazard prevention and control technology, specifically to a simulation test device and method for mine water recharge inducing water inrush in fault-bounded structures. Background Technology

[0002] Coal is one of my country's important basic energy sources. With the continuous increase in coal mining depth and intensity, the amount of mine water generated is constantly rising, leading to higher costs and stricter environmental constraints in its discharge, treatment, and disposal. Deep well reinjection technology for mine water involves reinjecting pre-treated mine water into deep aquifers or relatively closed reservoirs through underground or surface drilling, enabling the transfer, storage, and resource utilization of mine water. Compared with some deep treatment processes for high-salinity mine water, this technology has advantages such as stronger engineering adaptability and relatively lower overall costs, showing broad application prospects in green coal mining and the protection and management of groundwater resources in mining areas.

[0003] However, during deep well reinjection, the injected fluid causes changes in the groundwater dynamic field and pore pressure field. These changes, combined with the surrounding rock stress field and temperature field, lead to the evolution of permeable structures in tectonic formations (faults, collapse columns, and their fracture zones), i.e., fault activation, which may induce water inrush disasters. For example, changes in fracture aperture and slippage may expand seepage channels; particle migration may cause local scouring or blockage, resulting in abrupt changes in permeability; under unfavorable conditions, it may even induce the connection of tectonic channels or the reactivation of existing water source channels, thereby triggering the risk of water inrush disasters. Especially in tectonically developed areas, the stress redistribution and permeable structure instability caused by reinjection significantly reduce the reinjection safety margin.

[0004] Current research on "recharge-tectonic response-water inrush early warning" mainly relies on theoretical analysis, numerical simulation, and field monitoring. Due to the complexity of deep geological conditions, high drilling costs, and strong heterogeneity of the medium, it is often difficult to obtain complete, continuous, and comparable multi-field coupled evolution data in the field. In laboratory research, existing high-temperature and high-pressure core seepage devices or water-rock reaction test devices mostly use intact cores, focusing on the variation patterns of parameters such as permeability, porosity, and dissolution-precipitation under given pressure, temperature, and hydrochemical conditions. However, because the samples and boundary conditions are relatively idealized, and the devices are mostly based on the simplified assumption of "one-dimensional axial seepage and approximately homogeneous medium," it is usually difficult to simultaneously achieve the controlled construction and parameter adjustment of fault-type structures, the recharge disturbance loading under temperature and confining pressure conditions, and the synchronous monitoring and early warning verification of activation capacity, tectonic displacement, and water inrush risk on the same test platform. Therefore, it is difficult to provide direct and comparable experimental data support for recharge parameter optimization and safety assessment. Therefore, there is an urgent need for an indoor physical simulation test device and method that can controllably construct fault-collapse-like structures indoors and reproduce the evolution process of water inrush induced by reinjection under coupled loading conditions such as temperature, confining pressure, and seepage pressure difference; at the same time, it can realize the synchronous monitoring of key parameters such as activation characterization indicators and structural displacement response, and support risk classification early warning and linkage control. Summary of the Invention

[0005] The purpose of this invention is to provide a simulation test device and method for mine water reinjection-induced water inrush in fault-bounded structures, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention proposes a simulation test device for mine water reinjection inducing water inrush in fault-bounded structures, comprising: a mine water supply and control system for storing and transporting mine water, and controlling the injection pressure and flow rate to simulate reinjection conditions.

[0007] The water inrush simulation box is connected to the mine water supply and control system via pipelines. It is equipped with a reservoir medium filling cavity, a recharge layer simulation chamber and a structural simulation system to simulate fault-bounded structures and geological environments.

[0008] The real-time monitoring system is connected to the water inrush simulation box and the mine water supply and control system. It is used to collect and process data on confining pressure, inlet pressure, outlet pressure, flow rate, temperature and structural displacement in real time, and output four-level water inrush risk warning and linkage control commands based on multi-source data fusion and improved Bayesian discriminant algorithm.

[0009] As a further embodiment of the present invention, the mine water supply and control system includes: a water supply tank for storing mine water or simulated mine water; a flow pump connected to the water supply tank via a first inlet pipe and connected to the water inrush simulation box via a second inlet pipe; the water supply tank is provided with an insulation sleeve, and the flow pump is equipped with a pressure gauge, a back pressure valve and a thermometer to achieve constant pressure, constant flow or constant pressure-constant flow switching reinjection conditions.

[0010] As a further embodiment of the present invention, the water inrush simulation box comprises, from the inside out: a reservoir medium filling cavity for filling rock cores and porous media; a recharge layer simulation chamber located above or inside the reservoir medium filling cavity; a water-proof layer wrapped around the outside of the reservoir medium filling cavity; a rubber sleeve wrapped around the outside of the water-proof layer, with a confining pressure interface at its bottom for connecting a confining pressure pump; and a temperature control jacket wrapped around the outside of the rubber sleeve and connected to a temperature controller.

[0011] As a further embodiment of the present invention, the structural simulation system includes: several support plates disposed on the left and right sides of the reservoir medium filling cavity for supporting rock cores or medium blocks; a telescopic connection structure connecting adjacent support plates; a gear track fixed to the side plate of the water inrush simulation box; gears disposed on the gear track; a base connected between four gears in two adjacent rows; and a telescopic rod with its fixed end disposed on the base and its output end connected to the support plate. By adjusting the position of the gears on the gear track and the telescopic rod's extension and retraction, the relative displacement, misalignment displacement, and fracture opening of the support plates can be changed.

[0012] As a further embodiment of the present invention, the real-time monitoring system includes: a data acquisition unit for acquiring confining pressure, inlet pressure, outlet pressure, flow rate, and temperature data; a displacement monitoring subsystem including a laser displacement sensor for non-contact measurement of the relative displacement of the bearing plate in the structural simulation system; a data processing unit for preprocessing the acquired data, determining the weights of each monitoring feature based on grey relational analysis, and then combining an improved Bayesian discriminant algorithm to perform a four-level risk state discrimination; and an early warning output unit for generating control commands to coordinate and regulate at least one of the following when the determined risk reaches a critical level or a water inrush level: injection flow rate, injection pressure, seepage pressure difference, outlet back pressure, confining pressure, or temperature.

[0013] Secondly, the present invention also proposes a simulation test method for mine water recharge-induced fault-bounded water inrush, which is used in the above-mentioned simulation test device for mine water recharge-induced fault-bounded water inrush. The method includes the following steps: S1: According to the hydrogeological and structural characteristics of the recharge layer, a representative rock core is fixed on a bearing plate; by adjusting the structural simulation system, the bearing plate forms a preset displacement and fracture opening to simulate fault-bounded structures; then, artificial porous media is filled into the gaps between the rock cores and compacted to make the filling uniform and dense to simulate the in-situ compaction state; if necessary, an appropriate amount of groundwater is injected to saturate and vent the air, so that the medium and the rubber sleeve adhere to form stable boundary conditions.

[0014] S2: Prepare real mine water or simulated mine water formulated according to the chemical characteristics of the target mine water.

[0015] S3: Inject mine water into the water supply tank, adjust it to the set initial inlet temperature through the insulation sleeve, and record it.

[0016] S4: Start the confining pressure pump to apply confining pressure to the rubber sleeve through the confining pressure interface; start the temperature controller to heat the temperature control jacket so that the internal temperature of the simulation chamber reaches the set formation temperature; maintain the confining pressure and temperature stable until the initial equilibrium of the test is reached.

[0017] S5: Start the flow pump to inject mine water into the water inrush simulation box. By adjusting the injection conditions of the flow pump and the back pressure setting of the back pressure valve, the inlet pressure and outlet pressure meet the preset seepage pressure difference.

[0018] S6: During the reinjection process, multi-source data is collected synchronously through a real-time monitoring system, and real-time risk identification and early warning are performed based on grey relational analysis and improved Bayesian discriminant algorithm. When the risk level reaches the critical level or the water inrush level, linkage control commands are generated and executed to adjust relevant operating parameters.

[0019] S7: After the reinjection cycle ends, stop the injection and gradually remove the seepage pressure difference, confining pressure and temperature loading; discharge the fluid in the simulation box through the drain hole and drainage pipe; disassemble the rock core and filling medium, and observe and sample the morphology of the failure zone, particle migration characteristics and seepage channels for analysis.

[0020] As a further aspect of the present invention, the specific steps of real-time risk assessment in step S6 include:

[0021] S61: Real-time acquisition of confining pressure Pc(t), inlet pressure Pin(t), outlet pressure Pout(t), flow rate Q(t), temperature T(t), and relative displacement d(t) of the bearing plate.

[0022] S62: Calculate the seepage pressure difference.

[0023] S63: Perform time synchronization, noise reduction, anomaly removal and dimensionless processing on each monitoring sequence to form a feature sequence and construct an equivalent activation capacity index.

[0024] S64: Construct the activation mutation index.

[0025] S65: Further construct the displacement change rate.

[0026] S66: Construct a reference sequence X0 to characterize the evolution of the conduction capacity of fault-type structures. The activation mutation index or its rate of change is preferably used as the reference sequence. Grey relational analysis (GRA) is used to calculate the correlation between each feature sequence and the reference sequence, and the correlation is normalized to obtain the feature weight vector.

[0027] S67: The risk level is defined as four levels: stable level C1, evolving level C2, critical level C3, and flood level C4.

[0028] S68: Introduce GRA weights to weight the conditional probability terms of each feature, so that features more relevant to the construction of conduction have a higher weight in the discrimination.

[0029] S69: Based on the confining pressure Pc(t) and temperature T(t), the prior probability is adaptively corrected according to the working condition to improve the generalization ability under different confining pressure or temperature conditions.

[0030] S610: Output the posterior probability of each level, and output the level with the highest posterior probability as the risk level at time t.

[0031] S611: When the posterior probability of the critical level is not less than the first threshold and the preset number of sampling points is met continuously, a critical warning is output; when the posterior probability of the water inrush level is not less than the second threshold and the preset number of sampling points is met continuously, a water inrush warning is output.

[0032] S612: After outputting a critical warning or a water inrush warning, generate control commands to adjust at least one of the following: injection flow rate, injection pressure, seepage differential pressure, outlet back pressure, confining pressure, and temperature. At the same time, record key monitoring data before and after the treatment to evaluate the treatment effect.

[0033] As a further aspect of the present invention, the control measures for the linkage control command in step S6 include:

[0034] When the risk level is critical, at least one of the following measures shall be taken: reducing the seepage pressure differential, reducing the injection flow rate, changing the outlet back pressure, and / or switching the reinjection control mode.

[0035] When the risk level is water inrush, take at least one of the following measures: stop injection, reduce injection flow rate to a safe value, reduce seepage pressure differential, adjust outlet back pressure, and / or implement a safety pressure relief strategy.

[0036] As a further aspect of the present invention, step S8 is also included: by changing the structural parameters of the constructed simulation system, the experiment is repeated under the same boundary conditions to compare the impact of different structural parameters on the risk of water inrush.

[0037] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention constructs an indoor physical test platform that can simultaneously simulate "deep well reinjection-tectonic activation-water inrush response", and can carry out reinjection condition simulation under confining pressure and temperature loading.

[0038] 2. This invention achieves adjustable and controllable position, displacement and fracture opening of fault-type structures through a structural simulation system, and is suitable for comparative tests of different structural types such as faults, collapse columns and fracture zones.

[0039] 3. This invention forms a stable boundary by applying pressure through a rubber sleeve, reducing bypass seepage and improving test repeatability and data comparability.

[0040] 4. This invention takes "equivalent activation capacity", "activation mutation index" and "relative displacement of bearing plate and its change rate" as the core to form a water inrush characterization system adapted to constant pressure and constant flow reinjection conditions, and can output four levels of risk status: stable, evolving, critical and water inrush.

[0041] 5. This invention can verify treatment strategies indoors: when the situation is determined to be critical or sudden water inrush, risk suppression and safety protection can be achieved by adjusting parameters such as injection flow rate, seepage pressure difference, and outlet back pressure, providing data support for engineering reinjection parameter optimization and safety evaluation. Attached Figure Description

[0042] Figure 1 A schematic diagram of the structure of a simulation test device for inducing water inrush in fault-bounded structures by mine water reinjection.

[0043] Figure 2 A schematic diagram of the water inrush simulation chamber in a simulation test device for inducing water inrush in fault-bounded structures by mine water reinjection.

[0044] Figure 3 This is a schematic diagram illustrating a practical application of simulating fault structure conditions.

[0045] In the diagram: 1. Mine water supply and control system; 2. Water inrush simulation box; 3. Water supply tank; 4. First water inlet pipe; 5. Flow pump; 6. Insulation jacket; 7. Recharge layer water storage chamber; 8. Base plate; 9. Drain hole; 10. Telescopic rod; 11. Telescopic connection structure; 12. Bearing plate; 13. Reservoir medium filling cavity; 14. Gear track; 15. Side plate; 16. Gear; 17. Drain pipe; 18. Flow meter; 19. Second water inlet pipe; 20. Stress monitoring system; 21. Temperature controller; 22. Temperature control jacket; 23. Rubber sleeve; 24. Waterproof layer; 25. Confining pressure interface; 26. Pressure gauge; 27. Confining pressure pump; 28. Sensor port; 29. ​​Recharge layer simulation chamber; 30. Real-time monitoring system; 31. Base; 32. Structural simulation system. Detailed Implementation

[0046] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0047] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0048] Please see Figures 1 to 3 In one embodiment of the present invention, a simulation test device for water inrush induced by mine water reinjection in fault subsidence structures mainly includes a mine water supply and control system 1, a water inrush simulation box 2, and a real-time monitoring system 30.

[0049] The mine water supply and control system 1 includes a water supply tank 3, a first inlet pipe 4, and a flow pump 5. The water supply tank 3 is used to store real mine water or artificially simulated mine water formulated according to the target water chemical characteristics. Its material is preferably corrosion-resistant (such as PE or PTFE-lined stainless steel). An insulation sleeve 6 is installed outside the tank to regulate the initial temperature of the injected fluid. The flow pump 5 is connected to the water supply tank 3 through the first inlet pipe 4 and to the flood inrush simulation tank 2 through the second inlet pipe 19. The flow pump 5 is equipped with a pressure gauge 26, a back pressure valve, and a thermometer. It can be set to constant pressure, constant flow, or mixed mode according to experimental requirements to simulate different reinjection conditions and precisely control the seepage pressure difference between itself and the flood inrush simulation tank 2.

[0050] The water inrush simulation chamber 2 is the core component of the simulation. Its side plate 15 and bottom plate 8 are made of high-strength corrosion-resistant materials, and the design pressure bearing capacity is preferably 5-10MPa. From the inside to the outside, the water inrush simulation chamber 2 includes: a reservoir medium filling cavity 13, which is used to fill the representative rock core of the target reservoir or artificially prepared porous media (such as quartz sand, ceramsite, etc.). The filling needs to be uniform and dense to simulate the in-situ compaction state. The reservoir medium filling cavity 13 can be equipped with a transparent observation window.

[0051] The reinjection layer simulation chamber 29 is located above the reservoir medium filling cavity 13 or at a specific location to simulate the reinjection target layer.

[0052] The water-proof layer 24 encloses the reservoir medium filling cavity 13, serving as a water-proof and protective layer.

[0053] The rubber sleeve 23 is wrapped around the waterproof layer 24. Its bottom is provided with a confining pressure interface 25, which is connected to a pressure gauge 26 and a confining pressure pump 27 through a pipeline. The confining pressure pump 27 can apply controllable confining pressure to the rubber sleeve 23, so that it fits tightly with the reservoir medium filling cavity 13, simulating formation confining pressure and reducing bypass seepage.

[0054] Temperature control jacket 22, wrapped around rubber sleeve 23, is connected to temperature controller 21. Temperature controller 21 is used to precisely control the temperature of temperature control jacket 22 to simulate deep formation temperature. The preferred temperature control range is 10-90℃, with an accuracy of ±0.5℃.

[0055] The water outlet of the water inrush simulation tank 2 is connected to the flow meter 18 through the drain pipe 17. The flow meter 18 is also equipped with a pressure gauge 26 and a back pressure valve to monitor the outlet flow, pressure and temperature, and to adjust the outlet back pressure to maintain the system pressure stability.

[0056] The simulated water inrush tank 2 has a recharge layer water storage chamber 7 at the bottom inside, and a stress monitoring system 20 is installed on the outside of the simulated water inrush tank 2. The stress monitoring system 20 is connected to each sensor port 28 installed inside the simulated water inrush tank 2.

[0057] The structural simulation system 32 is key to simulating fault-bounded structures. It is set on the left and right sides of the reservoir medium filling cavity 13 and includes several bearing plates 12, a telescopic connection structure 11, a gear track 14, gears 16, a base 31, and telescopic rods 10. The bearing plates 12 are used to fix the rock core or artificial medium block. The gear track 14 is welded or fixed to the side plate 15. The gears 16 can move and be positioned on the gear track 14. The base 31 is connected between the four gears 16 in two adjacent rows. The telescopic rods 10 (such as electric or hydraulic push rods) are installed on the base 31. The output end of the telescopic rods 10 is connected to the bearing plates 12. By coordinating the adjustment of the position of the gears 16 and the extension and retraction of the telescopic rods 10, the relative displacement, vertical misalignment, and fracture aperture between adjacent bearing plates 12 can be precisely controlled, thereby constructing structural models of faults, collapse columns, and fracture zones with different geometric parameters (such as position, dip angle, misalignment, and aperture).

[0058] The real-time monitoring system 30 connects sensors in various parts of the device for data acquisition, processing, and early warning. It includes a data acquisition unit that acquires confining pressure P from pressure gauge 26, flow meter 18, thermometer, etc. c (t), Inlet pressure P in (t), Export pressure P out Data on flow rate Q(t) and temperature T(t).

[0059] The displacement monitoring subsystem typically includes a high-precision laser displacement sensor, which non-contactly measures the relative displacement d(t) of the bearing plate 12 to characterize structural faulting and crack changes.

[0060] The data processing unit performs preprocessing on the collected raw data, including time synchronization, filtering and denoising, outlier removal, and dimensionless conversion. Then, based on grey relational analysis (GRA), it determines the association weights of each monitoring feature (such as Ke(t), ΔP(t), Vd(t), etc.) with the construction activation (with the activation mutation index Ic(t) as a reference). Finally, it uses an improved Bayesian discriminant algorithm (IBDA), which introduces GRA weights to weight the conditional probabilities and adaptively corrects the prior probabilities based on the real-time operating conditions (Pc(t), T(t)), to calculate the posterior probabilities of four risk levels: stable level (C1), evolutionary level (C2), critical level (C3), and water inrush level (C4).

[0061] The early warning output unit outputs the level with the highest posterior probability as the current risk state. When the posterior probability of the critical level continuously exceeds the first threshold, or the posterior probability of the water inrush level continuously exceeds the second threshold, the corresponding early warning is triggered. At the same time, control commands are generated to automatically adjust parameters such as injection flow rate, pressure, back pressure, confining pressure, or temperature by controlling actuators such as the flow pump 5, back pressure valve, confining pressure pump 27, and temperature controller 21, and to implement intervention measures.

[0062] The method for simulating water inrush in deep mine water recharge induced by the above-mentioned device includes the following steps: Step S1: Based on the hydrogeological and structural characteristics of the recharge layer, a representative rock core is fixed on the bearing plate 12. The structural simulation system 32 is adjusted to make the bearing plate 12 form a preset displacement and fracture opening to simulate the fault-like structure. Then, artificial porous medium is filled into the gap of the rock core and compacted to make the filling uniform and dense to simulate the in-situ compaction state. If necessary, an appropriate amount of groundwater is injected to saturate and vent the air, so that the medium and the rubber sleeve 23 are in contact to form a stable boundary condition.

[0063] Step S2: Prepare real mine water or simulated mine water prepared according to the chemical characteristics of the target mine water.

[0064] Step S3: Inject mine water into water supply tank 3, adjust it to the set initial inlet temperature through insulation sleeve 6 and record it.

[0065] Step S4: Start the confining pressure pump 27 to apply confining pressure to the rubber sleeve 23 through the confining pressure interface 25; start the temperature controller 21 to heat the temperature control jacket 22 so that the internal temperature of the water inrush simulation chamber 2 reaches the set formation temperature; maintain the confining pressure and temperature stable until the initial equilibrium of the test.

[0066] Step S5: Start the flow pump 5 to inject mine water into the water inrush simulation box 2. By adjusting the injection conditions of the flow pump 5 and the back pressure setting of the back pressure valve, the inlet pressure and outlet pressure meet the preset seepage pressure difference.

[0067] Step S6: Within the set reinjection cycle, the confining pressure, inlet and outlet pressure, flow rate, temperature and relative displacement of the bearing plate 12 are collected synchronously through the real-time monitoring system 30, and the conduction evolution and structural response process of the fault-type structure are recorded.

[0068] Step S7: After the reinjection cycle ends, stop the injection and gradually remove the seepage pressure difference, confining pressure and temperature loading; discharge the fluid in the water inrush simulation box 2 through the drain hole 9 and the drainage pipe 17; disassemble the rock core and filling medium, and observe and sample the morphology of the failure zone, particle migration characteristics and seepage channels for analysis.

[0069] Step S8: By constructing a simulation system 32, the structural parameters such as the relative displacement and crack opening of the bearing plate 12 are changed, and the test is repeated under the same temperature and confining pressure recharge boundary conditions to compare the impact of different structural parameters on the risk of water inrush.

[0070] Furthermore, this invention proposes a four-level risk warning method (GRA+IBDA) and device linkage control. In the real-time monitoring process of step S6, the following four-level risk warning method is preferably used to perform real-time identification and handling verification of water inrush evolution.

[0071] Step S61: Real-time acquisition: confining pressure Pc (t), Inlet pressure P in (t), Export pressure P out The sampling parameters are: flow rate Q(t), temperature T(t), and relative displacement d(t) of the bearing plate. The preferred sampling frequency is 2Hz, and the preferred recharge cycle is 1 hour.

[0072] Step S62: Calculate the seepage pressure difference: Equation (1); where, P represents the seepage pressure difference at time t. in (t) represents the inlet pressure; P out (t) represents export pressure.

[0073] Step S63: Perform time synchronization, noise reduction, anomaly removal, and dimensionless processing on each monitoring sequence to form a feature sequence. Construct an equivalent activation capacity index: Equation (2); where, Let Q(t) be the equivalent activation index at time t; and let Q(t) be the flow rate at time t. This is a preset constant used to avoid the denominator being zero.

[0074] Step S64: Construct the activation mutation index: Equation (3); where, The activation mutation index; It represents the average value of the equivalent activation index during the period of stable confining pressure and temperature before or during the initial stage of reinjection.

[0075] Step S65: Further construct the displacement change rate: Equation (4); where: d(t) represents the rate of change of displacement; d(t) represents the relative displacement of the bearing plate at time t. This represents the sampling time interval.

[0076] Step S66: Construct a reference sequence X0 to characterize the evolution of the conductivity of fault-like structures, preferably using the activation mutation index. Alternatively, its rate of change can be used as a reference sequence. Grey relational analysis (GRA) is used to calculate the correlation between each feature sequence and the reference sequence, and the correlation is normalized to obtain the feature weight vector. The preferred resolution coefficient ρ for grey relational analysis is 0.5. The correlation coefficient, correlation degree, and weight calculations for the grey relational analysis can be implemented using existing general grey relational analysis calculation methods, wherein the output weights satisfy... .

[0077] Step S67: Define the risk level as four levels: stable level C1, evolving level C2, critical level C3, and flood level C4.

[0078] IBDA improves upon Bayesian discrimination by the following step: Step S68: Introducing GRA weights to weight the conditional probability terms of each feature, giving higher weight to features more relevant to constructing conduction. Preferably, the weighted conditional probability terms can be represented in weighted logarithmic form: Equation (5); where, For feature vectors, For the i-th feature, For the corresponding weights.

[0079] Step S69: Based on the confining pressure P c The prior probability is adaptively corrected by the working condition using the temperature T(t) and the working condition T(t), which improves the generalization ability under different confining pressures or temperatures.

[0080] Step S610: Output the posterior probability of each level The risk level at time t is output as the level with the highest posterior probability.

[0081] Step S611: When the posterior probability of the critical level is not less than the first threshold and the preset number of sampling points is met continuously, output a critical warning; when the posterior probability of the flood level is not less than the second threshold and the preset number of sampling points is met continuously, output a flood warning. The preset number of sampling points is preferably 3-10.

[0082] Step S612: After outputting a critical warning or a water inrush warning, generate control commands to adjust at least one of the following: injection flow rate, injection pressure, seepage differential pressure, outlet back pressure, confining pressure, and temperature. Preferably: at the critical stage, take at least one of the following measures: reduce seepage differential pressure, reduce injection flow rate, change outlet back pressure, and / or switch the reinjection control mode; at the water inrush stage, stop injection or reduce the injection flow rate to a safe value, and combine at least one of the following measures: reduce seepage differential pressure, adjust outlet back pressure, and / or implement a safety pressure relief strategy for rapid protection. Simultaneously record key monitoring data before and after the treatment to evaluate the treatment effect.

[0083] This invention presents a simulation test device and method for mine water reinjection-induced water inrush in fault-depression structures. It constructs an indoor physical test platform capable of simultaneously simulating "deep well reinjection-tectonic activation-water inrush response," allowing for reinjection condition simulation under confining pressure and temperature loading. The structural simulation system 32 enables adjustable and controllable analysis of fault-depression structures' location, displacement, and fracture opening, suitable for comparative tests of different structural types such as faults, collapse columns, and fracture zones. A stable boundary is formed through rubber sleeve confining pressure loading, reducing bypass seepage and improving test repeatability and data comparability. Based on "equivalent activation capacity," "activation mutation index," and "relative displacement of the bearing plate and its rate of change," a water inrush characterization system adapted to constant pressure and constant flow reinjection conditions is established, capable of outputting four risk levels: stable, evolving, critical, and water inrush. The system allows for indoor verification of treatment strategies: when identified as critical or water inrush level, risk suppression and safety protection can be achieved by adjusting parameters such as injection flow rate, seepage pressure difference, and outlet back pressure, providing data support for engineering reinjection parameter optimization and safety evaluation.

[0084] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A simulation test device for inducing water inrush from faulted structure by mine water recharge, characterized in that, The application relates to a mine water supply and regulation system, a water inrush simulation box and a real-time monitoring system. The mine water supply and regulation system is used for storing and conveying mine water and regulating injection pressure and flow to simulate a recharging condition. The water inrush simulation box is connected with the mine water supply and regulation system through pipelines, and is internally provided with a reservoir medium filling cavity, a recharging layer simulation chamber and a structure simulation system, and is used for simulating a faulted structure and a stratum environment. The real-time monitoring system is connected with the water inrush simulation box and the mine water supply and regulation system, is used for collecting and processing surrounding pressure, inlet pressure, outlet pressure, flow, temperature and structure displacement data in real time, and outputs four-stage water inrush risk early warning and linkage control instructions based on multi-source data fusion and an improved Bayesian discriminant algorithm.

2. The simulation test device for mine water recharging induced water inrush in faulted structure according to claim 1, characterized in that, The mine water supply and regulation system comprises a water supply tank used for storing mine water or simulated mine water, a flow pump connected with the water supply tank through a first water inlet pipe and connected with the water inrush simulation box through a second water inlet pipe, and a heat preservation sleeve arranged outside the water supply tank. The water inrush simulation box comprises, from inside to outside, a reservoir medium filling cavity used for filling rock cores and porous media, a recharging layer simulation chamber arranged above or in the reservoir medium filling cavity, an aquiclude wrapped outside the reservoir medium filling cavity, a rubber sleeve wrapped outside the aquiclude and provided with a surrounding pressure interface at the bottom for connecting a surrounding pressure pump, and a temperature control jacket wrapped outside the rubber sleeve and connected with a temperature controller. The structure simulation system comprises a plurality of bearing plates arranged on the left and right sides of the reservoir medium filling cavity and used for bearing rock cores or medium blocks, a telescopic connecting structure connecting adjacent bearing plates, a gear track fixed on a side plate of the water inrush simulation box, a gear arranged on the gear track, a base connected between four gears of two adjacent rows, and a telescopic rod with a fixed end arranged on the base and an output end connected with the bearing plate. The relative displacement, dislocation displacement and fracture opening of the bearing plate can be changed by adjusting the position of the gear on the gear track and the telescopic amount of the telescopic rod.

3. The simulation test device for mine water recharge-induced water inrush in faulted structure according to claim 2, characterized in that, The real-time monitoring system comprises a data acquisition unit used for acquiring surrounding pressure, inlet pressure, outlet pressure, flow and temperature data, a displacement monitoring subsystem comprising a laser displacement sensor and used for non-contact measurement of the relative displacement of the bearing plate in the structure simulation system, a data processing unit used for pre-processing the acquired data, determining the weight of each monitoring feature based on grey correlation analysis, and performing four-stage risk state discrimination in combination with an improved Bayesian discriminant algorithm, and an early warning output unit used for generating a control instruction to link and regulate at least one of injection flow, injection pressure, seepage pressure difference, outlet back pressure, surrounding pressure or temperature when the discriminated risk reaches a critical stage or a water inrush stage. The application further discloses a water inrush risk early warning method. The method comprises the following steps: ​ ​ ​ 4. The simulation test device for mine water recharge-induced water inrush in faulted structure according to claim 3, characterized in that, ​ ​ ​ ​ ​ ​ ​ ​ 5. The simulation test device for mine water recharging induced water inrush in faulted structure according to claim 4, characterized in that, ​ 6. A simulation test method of mine water recharge induced water inrush in faulted structure, for the simulation test device of mine water recharge induced water inrush in faulted structure according to any one of claims 1-5, characterized in that, ​ S1: According to the hydrogeological characteristics and structural characteristics of the recharge layer, fix the representative core on the bearing plate; adjust the tectonic simulation system to make the bearing plate form a preset dislocation displacement and fracture opening to simulate a rift-type structure, then fill the gap between the cores with artificial porous media and compact it to simulate the in-situ compaction state, and if necessary, inject a proper amount of groundwater to saturate and vent to make the medium and rubber sleeve fit to form a stable boundary condition; S2: Prepare real mine water or simulated mine water prepared according to the chemical characteristics of the target mine water; S3: Inject mine water into the water supply tank, adjust to the set initial temperature of the inlet through the heat preservation sleeve and record; S4: Start the confining pressure pump to apply confining pressure to the rubber sleeve through the confining pressure interface; start the temperature controller to heat the temperature control jacket to make the internal temperature of the simulation box reach the set formation temperature; keep the confining pressure and temperature stable to the initial equilibrium of the test; S5: Start the flow pump to inject mine water into the water inrush simulation box, adjust the injection conditions of the flow pump and the back pressure of the back pressure valve to make the inlet pressure and outlet pressure meet the preset seepage pressure difference; S6: During the recharge process, real-time monitoring system synchronously collects multi-source data, and based on gray correlation analysis and improved Bayesian discriminant algorithm, real-time risk discrimination and early warning are carried out, when the risk level reaches the critical level or the water inrush level, the linkage control instruction is generated and executed to adjust the relevant operating parameters; S7: After the recharge period, stop injection, gradually remove the seepage pressure difference, confining pressure and temperature loading; discharge the fluid in the simulation box through the water outlet and drainage pipe; disassemble the core and filling medium, and observe and sample analyze the damage belt shape, particle migration characteristics and permeation channel.

7. The method according to claim 6, wherein, The specific steps of real-time risk discrimination in step S6 include: S61: Real-time acquisition of confining pressure Pc(t), inlet pressure Pin(t), outlet pressure Pout(t), flow rate Q(t), temperature T(t) and relative displacement d(t) of the bearing plate; S62: Calculate the seepage pressure difference; S63: Time synchronization, denoising, abnormality rejection and dimensionless processing are performed on each monitoring sequence to form a characteristic sequence and construct an equivalent activation capacity index; S64: Construct the activation mutation index; S65: Further construct the displacement change rate; S66: Construct the reference sequence X0 to represent the evolution of the conductivity of the rift-type structure, preferably use the activation mutation index or its change rate as the reference sequence, use gray correlation analysis GRA to calculate the correlation degree of each characteristic sequence and the reference sequence, and normalize the correlation degree to obtain a characteristic weight vector; S67: Define the risk level as four levels: stable level C1, evolution level C2, critical level C3 and water inrush level C4; S68: Introduce the GRA weight to weight the conditional probability items of each feature, so that the features more related to the conductivity of the structure have higher weight in the discrimination; S69: According to the confining pressure Pc(t) and the temperature T(t), adaptively correct the prior probability according to the working condition, and improve the generalization ability under different confining pressures or temperatures; S610: Output the posterior probability of each level, and output the level with the maximum posterior probability as the risk level at time t. S611: When the critical level posterior probability is not less than the first threshold value and the preset sampling point number is continuously satisfied, outputting a critical early warning, and when the water inrush level posterior probability is not less than the second threshold value and the preset sampling point number is continuously satisfied, outputting a water inrush early warning; S612: After outputting the critical early warning or the water inrush early warning, generating a control instruction and being used for adjusting at least one of the injection flow, the injection pressure, the seepage pressure difference, the outlet back pressure, the confining pressure and the temperature, and recording key monitoring data before and after treatment for evaluating treatment effect.

8. The method according to claim 7, wherein, The regulation and control measures of the linkage control instruction in step S6 include: When the risk is a critical level, at least one of the following measures is taken: reducing the seepage pressure difference, reducing the injection flow, changing the outlet back pressure and / or switching the control mode of the backfill; When the risk is a water inrush level, at least one of the following measures is taken: stopping injection, reducing the injection flow to a safety value, reducing the seepage pressure difference, adjusting the outlet back pressure and / or executing a safety pressure relief strategy.

9. The method according to claim 8, wherein, Step S8: Repeating the test under the same boundary conditions by changing the structural parameters of the constructed simulation system to compare the influence of different structural parameters on the water inrush risk.

Images