A simulation test device and method for inducing water inrush in a faulted structure by mine water recharge

Abstract

The application discloses a simulation test device and method for mine water recharge-induced water inrush in faulted structure, relates to the technical field of mine water disaster prevention and control, and comprises a mine water supply and regulation system, a water inrush simulation box and a real-time monitoring system. The water inrush simulation box is internally provided with an adjustable structure simulation system, can construct fault or subsided column models with different parameters, and applies confining pressure and temperature through a rubber sleeve and a temperature control jacket to simulate deep stratum environment. The real-time monitoring system synchronously collects multi-field coupling data, and realizes real-time discrimination and early warning of four levels of risks, namely, stable, evolution, criticality and water inrush, based on grey correlation analysis and an improved Bayes discriminant algorithm. When the risk escalates, the system automatically links and regulates recharge parameters to realize safe disposal. The application can controllably reproduce the whole process of deep well recharge-induced structural activation water inrush, and provides effective indoor test means and data support for risk evaluation and prevention and control strategy formulation of the recharge project.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine water disaster prevention, and particularly relates to a simulation test device and method for mine water induced water inrush in faulted structure. BACKGROUND

[0002] Coal is one of the important basic energy sources in China. With the continuous increase of coal mining depth and mining intensity, the amount of mine water is increasing, and its discharge, treatment and disposal face higher costs and stricter environmental protection constraints. The mine water deep well injection technology can realize the transfer and storage of mine water and resource utilization by injecting the pretreated mine water into deep aquifer or relatively closed reservoir through underground or surface drilling. Compared with the deep treatment process of part of high-salt mine water, this technology has the advantages of strong engineering adaptability and relatively low comprehensive cost, and has broad application prospects in green mining of coal mine and protection and management of groundwater resources in mining area.

[0003] However, during the deep well injection process, the injected fluid will cause changes in the groundwater dynamic field and pore pressure field, and will act together with the stress field and temperature field of the surrounding rock, resulting in evolution of the permeation structure of the structure type (fault, collapse column and other structures and their fracture zones), i.e. fault activation, which may induce the occurrence of water inrush disaster. For example, the change of fracture aperture and dislocation slip may expand the seepage channel; particle migration may cause local scouring or plugging, making the permeability present a sudden change characteristic; under adverse conditions, it may even induce the connection of structural channels or the reactivation of existing water source channels, thereby causing the risk of water inrush disaster. Especially in the structure development area, the stress redistribution and permeation structure instability caused by injection will significantly reduce the safety margin of injection.

[0004] At present, the research on "recharge-structure response-inrush warning" mainly relies on theoretical analysis, numerical simulation and field monitoring. Influenced by the complex deep geological conditions, high cost of borehole detection, strong heterogeneity of medium and other factors, it is often difficult to obtain complete, continuous and comparable multi-field coupling evolution data in the field. In the laboratory research, the existing high temperature and high pressure core permeation device or water-rock reaction test device mainly takes the complete core as the object, and focuses on the variation law of permeability, porosity and dissolution-precipitation parameters under the given pressure, temperature and water chemical conditions; but due to the idealization of the sample and boundary conditions, and the simplification assumption of "one-dimensional axial seepage, approximately homogeneous medium" of the device, it is usually difficult to realize the controllable construction and parameter adjustment of faulted structure, the recharge disturbance loading under temperature- confining pressure conditions, and the synchronous monitoring and early warning disposal verification of activation capacity-structure displacement-inrush risk on the same test platform, so as to provide direct and comparable test data support for the optimization and safety evaluation of recharge parameters. Therefore, an indoor physical simulation test device and method is urgently needed: which can controllably construct faulted structure in the laboratory, and reproduce the evolution process of inrush induced by recharge under the coupling loading conditions of temperature-confining pressure-seepage pressure difference; at the same time, realize the synchronous monitoring of key parameters such as activation characterization index and structure displacement response, and support risk grading early warning and linkage control. SUMMARY

[0005] The purpose of the present application is to provide a simulation test device and method for mine water recharge induced faulted structure inrush, in order to solve the problems raised in the above background technology.

[0006] To achieve the above purpose, the present application provides the following technical scheme: In the first aspect, the present application provides a simulation test device for mine water recharge induced faulted structure inrush, comprising: a mine water supply and control system for storing and transporting mine water, and adjusting injection pressure and flow to simulate recharge conditions.

[0007] A water inrush simulation box is connected to the mine water supply and control system through a pipeline, and has a reservoir medium filling cavity, a recharge layer simulation chamber and a structure simulation system inside, for simulating faulted structure and stratum environment.

[0008] A real-time monitoring system is connected to the water inrush simulation box and the mine water supply and control system, for real-time acquisition and processing of confining pressure, inlet pressure, outlet pressure, flow, temperature and structure displacement data, and outputting four-level inrush risk early warning and linkage control instructions based on multi-source data fusion and improved Bayesian discriminant algorithm.

[0009] As a further scheme of the present application, the mine water supply and regulation system comprises: a water supply tank 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; a heat preservation sleeve is arranged outside the water supply tank, and the flow pump is provided with a pressure gauge, a back pressure valve and a thermometer to realize constant pressure, constant flow or constant pressure-constant flow switching recharging conditions.

[0010] As a further scheme of the present application, the water inrush simulation box comprises, from inside to outside: 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; an aquiclude wrapped outside the reservoir medium filling cavity; a rubber sleeve wrapped outside the aquiclude, and a confining pressure interface is arranged at the bottom of the rubber sleeve for connecting a confining pressure pump; and a temperature control jacket wrapped outside the rubber sleeve and connected with a temperature controller.

[0011] As a further scheme of the present application, the construction simulation system comprises: a plurality of bearing plates arranged on the left and right sides of the reservoir medium filling cavity for bearing rock cores or medium blocks; a telescopic connecting structure connecting adjacent bearing plates; a gear track fixed on the side plate of the water inrush simulation box; a gear arranged on the gear track; a base connected between the four gears of adjacent two rows; and a telescopic rod with a fixed end arranged on the base and an output end connected with the bearing plate; by adjusting the position of the gear on the gear track and the telescopic amount of the telescopic rod, the relative displacement, the fault displacement and the fracture opening of the bearing plate can be changed.

[0012] As a further scheme of the present application, the real-time monitoring system comprises: a data acquisition unit for acquiring confining pressure, inlet pressure, outlet pressure, flow rate and temperature data; a displacement monitoring subsystem comprising a laser displacement sensor for non-contact measurement of the relative displacement of the bearing plate in the construction simulation system; a data processing unit for pre-processing the collected data, determining the weight of each monitoring feature based on grey correlation analysis, and combining an improved Bayesian discriminant algorithm to determine the four-level risk state; and an early warning output unit for generating a control instruction to link and control at least one of the injection flow rate, the injection pressure, the seepage pressure difference, the outlet back pressure, the confining pressure or the temperature when the risk reaches the critical level or the water inrush level.

[0013] In a second aspect, the present application further provides a simulation test method for mine water recharging induced water inrush in faulted structure, which is used for the simulation test device for mine water recharging induced water inrush in faulted structure and comprises the following steps.

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

[0015] S3: injecting mine water into the water supply tank, adjusting to the set initial temperature of the inlet through the heat preservation sleeve and recording.

[0016] S4: starting the confining pressure pump to apply confining pressure to the rubber sleeve through the confining pressure interface; starting the temperature controller to heat the temperature control jacket so that the internal temperature of the simulation box reaches the set formation temperature; keeping the confining pressure and temperature stable to the initial equilibrium of the test.

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

[0018] S6: during the recharging process, synchronously collecting multi-source data through the real-time monitoring system, and performing real-time risk discrimination and early warning based on gray correlation analysis and improved Bayesian discrimination algorithm, when the risk level reaches the critical level or the water inrush level, generating and executing linkage control instructions to adjust the relevant operating parameters.

[0019] S7: stopping injection after the recharging cycle is completed, gradually removing the seepage pressure difference, confining pressure and temperature loading; discharging the fluid in the simulation box through the water outlet hole and the drain pipe; disassembling the core and the filling medium, and observing and sampling the damage belt shape, particle migration characteristics and permeation channel.

[0020] As a further scheme of the present application, the specific steps of real-time risk discrimination in step S6 include.

[0021] S61: real-time collection 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: calculating the seepage pressure difference.

[0023] S63: Time synchronization, denoising, abnormality rejection and dimensionless processing are performed on each monitoring sequence to form a characteristic sequence, and an equivalent activation capacity index is constructed.

[0024] S64: An activation mutation index is constructed.

[0025] S65: A displacement change rate is further constructed.

[0026] S66: A reference sequence X0 is constructed to represent the evolution of the rift-type tectonic conductivity, preferably using the activation mutation index or the change rate thereof as the reference sequence, and the correlation degree between each characteristic sequence and the reference sequence is calculated by using gray correlation analysis GRA, and the correlation degree is normalized to obtain a characteristic weight vector.

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

[0028] S68: The conditional probability items of each feature are weighted by introducing the GRA weight, so that the feature quantity more related to tectonic conductivity has a higher weight in discrimination.

[0029] S69: The prior probability is self-adaptively corrected according to the confining pressure Pc(t) and the temperature T(t), so as to improve the generalization ability under different confining pressures or temperatures.

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

[0031] S611: When the critical level posterior probability is not less than the first threshold and continuously satisfies the preset sampling point number, a critical early warning is output, and when the water bursting level posterior probability is not less than the second threshold and continuously satisfies the preset sampling point number, a water bursting early warning is output.

[0032] S612: After outputting the critical early warning or the water bursting early warning, a control instruction is generated and used to adjust 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 the key monitoring data before and after treatment are recorded for evaluating the treatment effect.

[0033] As a further scheme of the present application, the regulation and control measures of the linkage control instruction in step S6 include.

[0034] When the risk is the critical level, at least one of the measures of reducing the seepage pressure difference, reducing the injection flow, changing the outlet back pressure and / or switching the control mode of the backfill is taken.

[0035] When the risk is the water bursting level, at least one of the measures of 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 is taken.

[0036] As a further scheme of the present application, it further comprises the step S8 of repeating the test under the same boundary condition by changing the structural parameter of the structure simulation system to compare the influence of different structural parameters on the water inrush risk.

[0037] Compared with the prior art, the present application has the beneficial effects that: 1. The present application constructs an indoor physical test platform which can simulate the conditions of "deep well recharging-structure activation-water inrush response" at the same time, and can carry out recharging condition simulation under confining pressure and temperature loading.

[0038] 2. The present application realizes the adjustable and controllable of the faulted structure position, dislocation displacement and fracture opening degree through the structure simulation system, and is suitable for comparative tests of different structural types such as faults, collapse columns and fracture zones.

[0039] 3. The present application forms a stable boundary by confining pressure loading of the rubber sleeve, reduces bypass seepage, and improves the repeatability and data comparability of the test.

[0040] 4. The present application takes "equivalent activation capacity", "activation mutation index" and "relative displacement of bearing plate and its change rate" as the core, forms a water inrush representation system suitable for constant pressure and constant flow recharging conditions, and can output four levels of risk states of stable, evolution, critical and water inrush.

[0041] 5. The present application can verify the disposal strategy in the laboratory: when it is judged as critical or water inrush level, the risk can be inhibited and safety can be protected by adjusting the parameters such as injection flow, seepage pressure difference and outlet back pressure, which provides data support for engineering recharging parameter optimization and safety evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1 It is a structural schematic view of a simulation test device for water inrush of a faulted structure induced by mine water recharging.

[0043] Fig. 2 It is a structural schematic view of a water inrush simulation box in a simulation test device for water inrush of a faulted structure induced by mine water recharging.

[0044] Fig. 3 It is a practical application schematic view of simulating fault structure conditions.

[0045] In the figure: 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, heat preservation sleeve; 7, rechargeable layer water storage room; 8, bottom plate; 9, water outlet hole; 10, telescopic rod; 11, telescopic connecting 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, water-resisting layer; 25, confining pressure interface; 26, pressure gauge; 27, confining pressure pump; 28, sensor port; 29, rechargeable layer simulation room; 30, real-time monitoring system; 31, base; 32, tectonic simulation system. DETAILED DESCRIPTION

[0046] The technical solutions of the present application will be further described in detail below in combination with specific embodiments.

[0047] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0048] Please refer to Figs. 1 to 3 In one embodiment of the present application, a simulation test device for mine water recharge induced water inrush in faulted structure is provided, mainly comprising 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 comprises a water supply tank 3, a first water inlet pipe 4 and a flow pump 5. The water supply tank 3 is used to store real mine water or artificial simulated mine water prepared according to the target water chemical characteristics, and the material thereof is preferably a corrosion-resistant material (such as PE, PTFE lined stainless steel). A heat preservation sleeve 6 is provided outside the tank body for adjusting the initial temperature of the injected fluid. The flow pump 5 is connected with the water supply tank 3 through the first water inlet pipe 4 and connected with the water inrush simulation box 2 through the second water inlet pipe 19. The flow pump 5 is provided with a pressure gauge 26, a back pressure valve and a thermometer, and can be set to constant pressure, constant flow or mixed mode according to the test requirements, so as to simulate different recharge conditions and accurately control the seepage pressure difference between the flow pump 5 and the water inrush simulation box 2.

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

[0051] The recharge layer simulation chamber 29 is located above or at a specific position of the reservoir medium filling cavity 13, and simulates the recharge target layer.

[0052] The aquiclude 24 wraps the reservoir medium filling cavity 13 and plays a water-blocking and protective role.

[0053] The rubber sleeve 23 is wrapped outside the aquiclude 24, and the bottom thereof is provided with a confining pressure interface 25 connected to the pressure gauge 26 and the confining pressure pump 27 through a pipeline. The confining pressure pump 27 can apply a controllable confining pressure to the rubber sleeve 23, so that it is tightly attached to the reservoir medium filling cavity 13, simulates the formation confining pressure and reduces the bypass seepage.

[0054] The temperature control jacket 22 is wrapped outside the rubber sleeve 23 and is connected with the temperature controller 21. The temperature controller 21 is used to accurately control the temperature of the temperature control jacket 22, simulate the deep formation temperature, and the temperature control range is preferably 10-90℃, and the accuracy is ±0.5℃.

[0055] The water outlet of the water inrush simulation box 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, which is used to monitor the outlet flow, pressure and temperature, and adjust the outlet back pressure to keep the system pressure stable.

[0056] The recharge layer water storage chamber 7 is arranged at the inner bottom of the simulation water inrush box 2, and the stress monitoring system 20 is arranged outside the simulation water inrush box 2 and connected with the sensor ports 28 arranged inside the simulation water inrush box 2.

[0057] The structure simulation system 32 is the key to simulate the rifted structure, which is arranged on the left and right sides of the reservoir medium filling cavity 13, and includes a plurality of bearing plates 12, telescopic connecting structures 11, gear tracks 14, gears 16, bases 31 and telescopic rods 10. The bearing plates 12 are used to fix the rock cores or artificial medium blocks. The gear tracks 14 are welded or fixed on the side plates 15. The gears 16 can be positioned on the gear tracks 14. The base 31 is connected between the four gears 16 of the adjacent two rows. The telescopic rod 10 (such as an electric or hydraulic push rod) is installed on the base 31. The output end of the telescopic rod 10 is connected to the bearing plate 12. By cooperatively adjusting the positions of the gears 16 and the telescopic amount of the telescopic rod 10, the relative displacement, vertical dislocation and fracture opening between the adjacent bearing plates 12 can be accurately controlled, so that the structure model of the fault, collapse column fracture zone and the like with different geometric parameters (such as position, inclination angle, dislocation distance and opening) can be constructed.

[0058] The real-time monitoring system 30 is connected with the sensors of each part of the device, and is used for data acquisition, processing and early warning. The real-time monitoring system 30 includes a data acquisition unit, a displacement monitoring subsystem, a data processing unit and a warning output unit. c The data acquisition unit acquires the confining pressure P in (t), the inlet pressure P out (t), the outlet pressure P out (t), the flow rate Q(t) and the temperature T(t) data from the pressure gauge 26, the flow meter 18 and the thermometer.

[0059] The displacement monitoring subsystem generally includes a high-precision laser displacement sensor, and is used for non-contact measurement of the relative displacement d(t) of the bearing plate 12, so as to represent the dislocation and fracture change of the structure.

[0060] The data processing unit performs time synchronization, filtering and denoising, abnormal value elimination and dimensionless pretreatment on the acquired original data. Then, the correlation weight of each monitoring feature (such as Ke(t), ΔP(t) and Vd(t)) to the structure activation (with the activation mutation index Ic(t) as the reference) is determined based on the grey correlation analysis (GRA). Finally, the improved Bayesian discriminant algorithm (IBDA) is adopted, that is, the GRA weight is introduced to weight the conditional probability, and the prior probability is adaptively corrected according to the real-time working condition (Pc(t), T(t)), so as to calculate the posterior probability of the four risk levels of the stable level (C1), the evolution level (C2), the critical level (C3) and the water inrush level (C4).

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

[0062] The method for simulating water inrush of a faulted structure by using the device comprises the following steps in sequence: step S1: according to the hydrogeological characteristics and structural characteristics of the recharging layer, fixing a representative core on the bearing plate 12, adjusting the structural simulation system 32 to make the bearing plate 12 form a preset dislocation displacement and a preset fracture opening to simulate the faulted structure, then filling an artificial porous medium in the gap of the core and compacting the artificial porous medium, so that the filling is uniform and dense to simulate the in-situ compaction state, and if necessary, injecting a proper amount of underground water to saturate and venting to make the medium and the rubber sleeve 23 fit to form a stable boundary condition.

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

[0064] Step S3: injecting the mine water into the water supply tank 3, adjusting to the set initial temperature of the inlet through the heat preservation sleeve 6 and recording.

[0065] Step S4: starting the confining pressure pump 27 to apply confining pressure to the rubber sleeve 23 through the confining pressure interface 25, starting the temperature controller 21 to heat the temperature control jacket 22 to make the temperature inside the water inrush simulation box 2 reach the set formation temperature, and keeping the confining pressure and temperature stable to the initial equilibrium of the test.

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

[0067] Step S6: during the set recharging period, synchronously collecting data such as confining pressure, inlet and outlet pressure, flow, temperature and relative displacement of the bearing plate 12 through the real-time monitoring system 30, and recording the evolution of the faulted structure conduction and the structural response process.

[0068] Step S7: after the recharging period ends, stopping the injection, gradually removing the seepage pressure difference, the confining pressure and the temperature loading, discharging the fluid in the water inrush simulation box 2 through the water outlet hole 9 and the drain pipe 17, disassembling the core and the filling medium, and observing and sampling and analyzing the damage belt shape, particle migration characteristics and permeation channel.

[0069] Step S8: changing the structural parameters such as the relative displacement and the fracture opening of the bearing plate 12 through the structural simulation system 32, and repeating the test under the same temperature and confining pressure recharging boundary conditions, to compare the influence of different structural parameters on the water inrush risk.

[0070] Further, the application proposes a four-level risk early warning method (GRA+IBDA) and device linkage control. In the real-time monitoring process of step S6, the following four-level risk early warning method is preferably used to real-time distinguish and dispose the water inrush evolution.

[0071] Step S61: real-time collection: confining pressure Pc (t), the inlet pressure P in (t), the outlet pressure P out (t), the flow rate Q(t), the temperature T(t), and the relative displacement d(t) of the bearing plate. The sampling frequency is preferably 2 Hz, and the backfilling period is preferably 1 hour.

[0072] Step S62: calculate the seepage pressure difference: Formula (1); wherein, is the seepage pressure difference at time t; P in (t) is the inlet pressure; P out (t) is the outlet pressure.

[0073] Step S63: time synchronization, denoising, abnormality rejection, and dimensionless processing are performed on each monitoring sequence to form a feature sequence. An equivalent activation capacity index is constructed: Formula (2); wherein, is the equivalent activation index at time t; Q(t) is the flow rate at time t; is a preset constant, used to avoid a zero denominator.

[0074] Step S64: construct an activation mutation index: Formula (3); wherein, is the activation mutation index; is the average value of the equivalent activation index during the stable period of confining pressure and temperature before or at the beginning of backfilling.

[0075] Step S65: further construct a displacement change rate: Formula (4); wherein: is the displacement change rate; d(t) is the relative displacement of the bearing plate at time t; is the sampling time interval.

[0076] Step S66: construct a reference sequence X0 to represent the evolution of the faulted structure conductivity, and preferably use the activation mutation index or its change rate as the reference sequence. Grey correlation analysis (GRA) is used to calculate the correlation degree of each feature sequence and the reference sequence, and the correlation degree is normalized to obtain a feature weight vector . The grey correlation analysis resolution coefficient p is preferably 0.5. The correlation coefficient, correlation degree, and weight of the grey correlation analysis can be calculated using the existing general calculation method of grey correlation analysis, wherein the output weight satisfies .

[0077] Step S67: define the risk level as four levels: stable level C1, evolution level C2, critical level C3, and water inrush level C4.

[0078] IBDA makes the following improvements on the basis of Bayesian discrimination: step S68: introduce GRA weight to weight the conditional probability term of each feature, so that the feature quantity more related to the construction conduction occupies a higher weight in discrimination. Preferably, the weighted conditional probability term can be expressed in the form of weighted logarithm: Formula (5); wherein, is a feature vector, is the i-th feature, is the corresponding weight.

[0079] Step S69: according to the confining pressure P c (t) and the temperature T(t) to adaptively correct the prior probability under the working condition, and improve the generalization ability under different confining pressure or temperature conditions.

[0080] Step S610: output the posterior probability of each level , and output the level with the maximum posterior probability as the risk level at time t.

[0081] Step S611: output critical pre-warning when the critical level posterior probability is not less than the first threshold and continuously meets the preset sampling point number; output water inrush pre-warning when the water inrush level posterior probability is not less than the second threshold and continuously meets the preset sampling point number. The preset sampling point number is preferably 3-10.

[0082] Step S612: after outputting the critical pre-warning or the water inrush pre-warning, generate a control instruction and use it to adjust at least one of the injection flow rate, the injection pressure, the seepage pressure difference, the outlet back pressure, the confining pressure and the temperature: preferably: at least one of reducing the seepage pressure difference, reducing the injection flow rate, changing the outlet back pressure and / or switching to the backfill control mode is adopted at the critical level; at the water inrush level, at least one of stopping injection or reducing the injection flow rate to a safe value, combined with reducing the seepage pressure difference, adjusting the outlet back pressure and / or executing the safety pressure relief strategy is adopted for rapid protection treatment. At the same time, record the key monitoring data before and after the treatment, for evaluating the treatment effect.

[0083] The simulation test device and method of the mine water recharge induced water inrush of faulted structural, a laboratory physical test platform capable of simultaneously simulating "deep well recharge-structural activation-water inrush response" is constructed, and the recharge working condition simulation can be carried out under confining pressure and temperature loading; the adjustable and controllable of faulted structural position, dislocation displacement and fracture opening is realized through the structural simulation system 32, which is suitable for comparative test of different structural types such as fault, collapse column and fracture zone; the stable boundary is formed by confining pressure loading of rubber sleeve, the bypass seepage is reduced, and the test repeatability and data comparability are improved; the water inrush characterization system suitable for constant pressure and constant flow recharge working conditions is formed with "equivalent activation capacity", "activation mutation index" and "relative displacement of bearing plate and its change rate" as the core, and the four-level risk states of stable, evolution, critical and water inrush can be output; the indoor verification of disposal strategy can be carried out: when the critical level or water inrush level is judged, the risk inhibition and safety protection can be realized by adjusting the injection flow, seepage pressure difference, outlet back pressure and other parameters, which provides data support for the optimization of engineering recharge parameters and safety evaluation.

[0084] The above is only the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which should be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent.

Claims

1. A simulation test device for inducing water inrush in fault-bounded structures by mine water reinjection, characterized in that, include: A mine water supply and control system is used to store and transport mine water, and to control the injection pressure and flow rate to simulate reinjection conditions. The water inrush simulation box is connected to the mine water supply and control system via pipeline. 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. 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. The water inrush simulation chamber, from the inside out, includes: a reservoir medium filling cavity, used to fill rock cores and porous media; The reinjection layer simulation chamber is located above or inside the reservoir medium filling cavity; A waterproof layer is wrapped around the outside of the reservoir medium filling cavity; A rubber sleeve is wrapped around the outside of the waterproof layer, and a confining pressure interface is provided at the bottom for connecting a confining pressure pump. A temperature control jacket, wrapped around the outside of the rubber sleeve, is connected to the temperature controller; The construction simulation system includes: Several support plates are disposed on the left and right sides of the reservoir medium filling cavity to support the rock core or medium block; A retractable connection structure connects adjacent support plates; The gear track is fixed to the side plate of the water inrush simulation box; A gear is mounted on the gear track; The base is connected between the four gears in two adjacent rows; The telescopic rod has its fixed end mounted on the base and its output end connected to the support plate. By adjusting the position of the gear on the gear track and the extension and retraction of the telescopic rod, the relative displacement, misalignment displacement, and crack opening of the bearing plate can be changed. 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 determine a four-level risk state; 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.

2. The simulation test device for mine water reinjection inducing water inrush in fault-bounded structures according to claim 1, characterized in that, The mine water supply and control system includes: Water supply tanks are used to store mine water or simulated mine water; A flow pump is connected to the water supply tank through a first inlet pipe and to the water inrush simulation box through a second inlet pipe. The water supply tank is equipped with an insulation sleeve, and the flow pump is equipped with a pressure gauge, back pressure valve and thermometer to achieve constant pressure, constant flow or constant pressure-constant flow switching reinjection conditions.

3. A simulation test method for mine water recharge inducing water inrush in fault-bounded structures, used in the simulation test apparatus for mine water recharge inducing water inrush in fault-bounded structures as described in claim 1 or 2, characterized in that, Includes the following steps: S1: Based on the hydrogeological and structural characteristics of the recharge layer, representative rock cores are fixed on the bearing plate; by adjusting the structural simulation system, the bearing plate is made to form a preset displacement and fracture aperture to simulate a fault-bounded structure; 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; an appropriate amount of groundwater is injected to saturate and vent the air, so that the media and the rubber sleeve adhere to form stable boundary conditions; S2: Prepare real mine water or simulated mine water formulated according to the chemical characteristics of the target mine water; S3: Inject mine water into the water supply tank, adjust it to the set initial inlet temperature through the insulation sleeve, and record it; 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; 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. 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. 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.

4. The simulation test method for mine water reinjection inducing water inrush in fault-bounded structures according to claim 3, characterized in that, The specific steps of real-time risk assessment described 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: Perform time synchronization, noise reduction, anomaly removal and dimensionless processing 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 rate of change of displacement; S66: Construct a reference sequence X0 to characterize the evolution of the conduction capacity of fault-type structures. Use the activation mutation index or its rate of change as the reference sequence. Use grey relational analysis (GRA) to calculate the correlation between each feature sequence and the reference sequence, and normalize the correlation to obtain the feature weight vector. S67: The risk level is defined as four levels: stable level C1, evolutionary level C2, critical level C3, and flood level C4; 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. 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. S610: Output the posterior probability of each level, and output the level with the highest posterior probability as the risk level at time t. 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. 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 treatment to evaluate the treatment effect.

5. The simulation test method for mine water reinjection inducing water inrush in fault-bounded structures according to claim 4, characterized in that, The control measures for the linkage control command mentioned in step S6 include: When the risk is critical, take at least one of the following measures: reduce the seepage pressure difference, reduce the injection flow rate, change the outlet back pressure and / or switch the reinjection control mode. 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.

6. The simulation test method for mine water reinjection inducing water inrush in fault-bounded structures according to claim 5, characterized in that, It also includes step S8: 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.

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