A mine earthquake internal seismic source power similarity simulation test system and method based on metal wire electric explosion

Abstract

The present application relates to a kind of mine earthquake internal seismic source power similarity simulation test system and method based on metal wire electric explosion, pre-embedded metal wire electric explosion is used to form transient volume expansion seismic source in similar material model inside, it is realized by the conversion of the accurate release energy source from the external monotone extensive mechanical disturbance to model inside;Through the division of labour design of charging branch, main discharge branch, discharge branch and detection branch, make circuit organization relationship clear, protection chain is complete, it is convenient to stable implementation high voltage pulse discharge test;Through the current limiting inductance to the discharge current front and pulse width are adjusted, so that mine earthquake simulation is no longer only pay attention to total energy similarity, also consider time process similarity;The corresponding relationship between the energy of field mine earthquake event and the input electric energy of similar material model is established, the scientificity of test parameter setting is improved;Through cabinet type layered assembly, host computer software control and standardization experimental process organization, the repeatability, traceability and safety of device operation are improved.

Description

Technical Field

[0001] This invention relates to the field of physical simulation and similarity testing technology for mine dynamic disasters, and in particular to a similarity simulation test system and method for the internal source dynamics of mine earthquakes based on the electric explosion of metal wires. Background Technology

[0002] Mine tremors and rockbursts are common and highly destructive dynamic hazards during deep coal mining. Essentially, they represent a dynamic instability process in which coal and rock masses undergo local fracturing, energy accumulation, instantaneous release, and stress wave propagation under high static load conditions. Unlike static loading conditions, mine tremors are characterized not only by their location within the rock strata but also by short release durations, steep stress rises, rapid wave propagation, and significant inertial effects. Therefore, to realistically reproduce the gestation and manifestation of mine tremors in an indoor similar material model, conventional boundary loading, mechanical impact, or external disturbance methods alone are insufficient to simultaneously meet the requirements of internal source formation, energy level correspondence, and dynamic timescale matching.

[0003] Most current similarity simulation test systems are built on the traditional static similarity framework, focusing on geometric similarity, density similarity, and stress similarity. They reproduce the mining process through model boundary loading, step-by-step excavation, or additional external impacts. While these methods are applicable to studying overburden structure evolution, stress transfer, and stope deformation, they have significant shortcomings when simulating dynamic events like mine tremors triggered by sudden internal energy release: First, the seismic source is often located at the model boundary or attached to an external excitation end, making it difficult to form a true internal disturbance source; second, energy input methods are mostly empirically set, lacking a quantitative conversion relationship with the energy of actual mine tremor events; third, the release process is mainly based on mechanical impact or gradual loading, making it difficult to obtain the rapid pulse characteristics close to the mine tremor process. Patent CN118330723A discloses a mine tremor physical simulation test system based on microseismic acoustic emission joint monitoring. However, its seismic source relies on the passive fracture of the model material under loading, making it difficult to actively and precisely control the energy magnitude, release location, and occurrence time. This method cannot quantitatively and repeatedly simulate mine tremor events of specific energy levels. Patent CN111337575B discloses a vibration propagation test platform with variable source form and energy. Its source energy comes from the gravity potential energy of falling objects. The action mode is to impact the surface or shallow layer of the model. It cannot form an instantaneous volume expansion source at a predetermined depth inside the model. Moreover, its energy release characteristics do not match the microsecond to millisecond pulse process of mine tremors, and it lacks an energy conversion relationship based on the principle of dynamic similarity.

[0004] In the field of high-voltage pulsed discharge technology, although existing devices can perform high-voltage energy storage and pulsed discharge, these devices are typically designed for applications such as electro-explosive material testing, plasma generation, or industrial pulsed power supply. Their structural design focuses on discharge capacity, circuit insulation, and device protection, without integrating with coal mine seismic simulation systems. Furthermore, they lack a system for source energy conversion, model installation methods, control software coordination, and safe testing procedures based on dynamic similarity principles. In particular, there is a lack of integrated and specialized system designs for the energy storage and release technology chain required for simulating internal seismic sources in mine seismic simulations.

[0005] Furthermore, existing attempts at simulating internal seismic sources have the following shortcomings: First, the separation between the equipment structure and the model system is high, and the assembly relationship is unclear, resulting in poor repeatability of the test setup; second, the circuit loop description is insufficient, and there is a lack of clear organizational relationships between charging branches, protection branches, main discharge circuits, venting branches, and detection branches; third, the operation method relies heavily on manual experience, lacking upper-level computer software for parameter input, status monitoring, trigger control, fault indication, and waveform retention; fourth, the safety organization procedures during the test implementation, such as pre-testing, low-energy level verification, insulation inspection, grounding confirmation, and residual voltage release, are not systematic enough. Therefore, there is an urgent need to develop a dynamic similarity simulation system and working method for the internal seismic source of metal wire electric explosion that takes into account the actual assembly relationship, circuit organization logic, software control, and the requirements of mine vibration dynamic similarity. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a dynamic similarity simulation test system and method for internal seismic sources in mine earthquakes based on metal wire electric explosion. It is based on high-voltage pulse energy storage and controllable discharge, uses a pre-embedded metal wire load as the energy release carrier, and employs a current-limiting inductor and a discharge branch as waveform adjustment and safety assurance units. An external high-voltage electrode assembly is used to couple with a similar material model. A host computer operating software is used to complete parameter setting, charging control, discharge triggering, status display, and data management, thereby forming a repeatable, controllable, and verifiable transient seismic source within the similar material model.

[0007] In a first aspect, the present invention provides a simulation test system for the dynamic similarity of the internal seismic source of a mine earthquake based on the electric explosion of metal wire, comprising: a cabinet-type power supply host, a high-voltage circuit assembly disposed inside the cabinet-type power supply host, a high-voltage electrode assembly disposed outside the cabinet-type power supply host and connected to a similar material model, a host computer, an oscilloscope, and a similar material model; The high-voltage circuit assembly includes a high-voltage power supply, a main discharge switch control unit, a main discharge switch, a current-limiting inductor, a protective silicon stack and resistor unit, an energy storage capacitor, a manual discharge switch and a discharge resistor unit. The resistor unit includes a charging resistor and a protection resistor, and the discharge resistor unit includes a normal discharge resistor and a discharge protection resistor. A high-voltage power supply, a protection resistor, a protection silicon stack, a charging resistor, a freewheeling diode, and an energy storage capacitor are connected in sequence to form a charging branch, which is used to limit the current charging of the energy storage capacitor during the charging stage and block the reverse current to the high-voltage power supply during the discharging stage. The main discharge outlet of the energy storage capacitor, the main discharge switch control unit, the main discharge switch, the current limiting inductor, the high voltage connector, the high voltage electrode assembly and the metal wire load are connected in sequence to form the main discharge branch, which is used to quickly release the electrical energy in the energy storage capacitor to the metal wire load after the discharge is triggered. The discharge branch consists of a normal discharge resistor connected in parallel across the two ends of the energy storage capacitor and a confirmatory discharge branch consisting of a manual discharge switch and a discharge protection resistor connected in series. This branch is used to further eliminate the residual high voltage of the energy storage capacitor after the discharge is completed. The high-voltage electrode assembly includes a first electrode, a second electrode, an insulating fixing base, clamping terminals, and two high-voltage cables led out from the cabinet-type power supply host. The first electrode and the second electrode are fixed on the insulating fixing base, which is then connected to a similar material model support plate or a local mounting component. The front ends of the first electrode and the second electrode extend into the similar material model and are located at the target seismic source position. An adjustable gap is left between the two electrodes. The metal wire load is reliably crimped between the two electrodes through the clamping terminals. The two high-voltage cables are respectively connected to the rear connection terminals of the two electrodes. The host computer is connected to the cabinet-type power supply host via a communication cable. The host computer software is configured with functions such as device parameter setting, device communication status display, charging start / stop, discharge triggering, fault alarm, waveform monitoring, and data retention. An oscilloscope and a current probe are connected to a high-voltage probe to form a detection branch. The current probe is located on the return side of the main discharge branch and is used to simultaneously acquire the discharge voltage waveform and the current waveform.

[0008] Optionally, the metal wire load is made of fine copper wire.

[0009] Optionally, the software interface of the host computer includes at least a parameter setting area, a device status area, a control execution area, a real-time waveform area, a communication status area, and a data recording area; wherein, the parameter setting area is used to input information such as target charging voltage, energy storage level, trigger delay, and test number; the device status area is used to display communication status, charging status, waiting to be triggered status, discharging status, and fault status; the control execution area is used to perform charging, stopping, discharging, and reset operations; the real-time waveform area is used to display voltage waveforms and current waveforms; and the data recording area is used to save the timestamp, set parameters, and acquisition results of each test.

[0010] Optionally, the cabinet-type power supply unit adopts an assembly method combining upper and lower layers and left and right partitions: the top is equipped with a high-voltage power supply and its input interface, used to convert laboratory AC power into adjustable DC high voltage; the lower part of the top is equipped with a main discharge switch control unit, used to receive trigger signals from the host computer and output control commands to the main discharge switch; the upper middle part is equipped with the main discharge switch and the main discharge high-voltage wire, used as the starting switching node for energy storage release; the middle part is equipped with a current-limiting inductor, connected in series in the main discharge branch to shorten the length of the high current channel; the lower middle part is equipped with a protection silicon stack, charging resistor, and protection resistor, so that the charging branch, the main discharge branch, and the discharge branch are structurally separated from each other; the lower part is equipped with an energy storage capacitor; the normal discharge resistor, the discharge protection resistor, and the manual discharge switch are located near the energy storage capacitor; the bottom of the cabinet is equipped with high-voltage cables, grounding harnesses, and external connection interfaces.

[0011] Optionally, the cabinet-type power supply unit adopts a movable insulated metal cabinet, with casters and a grounding lead at the bottom of the cabinet, and an equipment door panel on the front.

[0012] Secondly, the present invention provides a method for simulating the dynamic similarity of the internal seismic source of a mine earthquake based on the electric explosion of a metal wire, comprising: Step 1, Data Acquisition and Conversion: Collect seismic monitoring data of the target mine and convert the seismic monitoring data to determine the target charging voltage; Step 2, Device Initialization and Safety Confirmation: Check the insulation status of the cabinet-type power supply host, the system grounding status, the integrity of the high-voltage cable, the reset status of the main discharge switch, the effectiveness of the discharge circuit, the communication status of the host computer, and the connection status of the oscilloscope; Step 3, Electrode installation and wire load embedding inside the model: Fix the first and second electrodes at the target source position of the similar material model, bridge the wire load of the pre-selected specification, and confirm that the electrode spacing, wire load tension and insulation isolation conditions meet the test requirements. Step 4, Inputting parameters and coordinating communication with the host computer: Input the simulation parameters in the host computer software and complete the communication confirmation. The simulation parameters include information such as target charging voltage, energy storage level, trigger delay, and test number. Step 5, Low-energy pre-test and loop verification: Set a pre-charge voltage lower than the formal test value in the host computer software, perform pre-charge and pre-discharge, and verify the high-voltage probe, current detection connector, waveform display and circuit connectivity. Step 6, Formal charging and discharging trigger: Perform formal charging. When the system reaches the set voltage, it enters the waiting state. The host computer issues a trigger command to control the main discharge switch to turn on, so that the energy storage capacitor releases to the metal wire load inside the similar material model through the current limiting inductor. Step 7, Waveform Acquisition and Result Storage: Synchronously record voltage, current, and required external response signals; Step 8, residual voltage discharge and circuit reset: After the discharge is completed, the residual energy is first released by the normal discharge branch, and then the manual discharge switch is operated for confirmation discharge. The load and electrodes can only be contacted after the capacitor residual voltage drops to a safe range. Step 9, repeat the test or change the working conditions: change the wire specifications, adjust the voltage parameters or change the location of the seismic source according to the test plan, and continue to the next set of tests.

[0013] Optionally, step 1 includes: According to similarity theory, the energy similarity ratio between the model material and the prototype coal and rock is... α E The calculation formula is: (1); In the formula, α ρ This represents the density similarity ratio between the model material and the prototype coal and rock. α L This represents the geometric similarity ratio between the model material and the prototype coal and rock. The theoretical energy storage calculation formula for energy storage capacitors is as follows: (2); In the formula, E c This represents the theoretical energy storage value of the energy storage capacitor. C This refers to the capacitance value of the energy storage capacitor. U This is the charging voltage; In on-site mine seismic events, the effective energy actually used to generate propagable shock disturbances. E e Represented as: (3); In the formula, λ This represents the energy transfer coefficient for the conversion of energy from a seismic event at the site into a propagable shock wave and kinetic energy. E s Energy from on-site mine seismic events; To consider the impact of the difference between the burial depth of the on-site seismic event and the burial depth of the model on energy propagation, a burial depth correction factor is introduced. η g The equivalent mechanical energy required by the earthquake source inside the model. E m The calculation formula is: (4); In the formula, η gThis is used to characterize the corrective effect of the difference between the burial depth of the on-site seismic event and the model burial depth on the effective energy propagation; Define the mechanical impact energy actually converted during the airburst of a metal wire as: E k Then we have: (5); In the formula, P(t) This is a curve showing the change of shock wave pressure over time as measured by a pressure sensor. ρ k The air density in an airburst environment. v k The speed of sound in an airburst environment. S k This represents the equivalent wavefront area at the corresponding measurement point distance; The energy conversion efficiency of an electrical explosion was obtained through an airburst calibration test. η c for: (6); Considering the energy conversion efficiency of an electric explosion η c Therefore, the required input electrical energy for the energy storage capacitor is: (7); In the formula, E c1 This refers to the input electrical energy that a capacitor should possess. Through equation (7), energy from on-site mine seismic monitoring E s Inverse calculation model power supply setting energy storage E c1 Then, the charging voltage is determined by combining equation (2). U This ensures that the internal seismic sources in similar experiments correspond to the target prototype events in terms of energy level.

[0014] By adopting the above technical solution, the present invention has at least the following beneficial effects: 1. By using a pre-embedded metal wire electro-explosion method to form a transient volume expansion vibration source inside a similar material model, the conversion from external monotonous and coarse mechanical disturbance to precise energy release inside the model is realized; 2. By designing the charging branch, main discharge branch, bleed branch, and detection branch separately, the circuit organization is clear, the protection chain is complete, and it is easy to stably implement high-voltage pulse discharge tests; 3. By adjusting the leading edge of the discharge current and the pulse width through a current-limiting inductor, the mine seismic simulation not only focuses on the similarity of total energy, but also takes into account the similarity of the time process; 4. By using airburst calibration and similarity conversion formulas, the correspondence between the energy of field mine seismic events and the input electrical energy of similar material models was established, which improved the scientific nature of the test parameter settings; 5. By using cabinet-style layered assembly, upper-computer software control, and standardized experimental procedures, the repeatability, traceability, and safety of the device operation have been improved. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the layout of the high-voltage circuit components inside the cabinet-type power supply unit of the present invention. Figure 2 This is a circuit diagram of the mine earthquake internal source dynamic similarity simulation test system of the present invention; Figure 3 This is a circuit parameter setting diagram of the mine seismic internal source dynamic similarity simulation test system of the present invention; Figure 4 The vibration waveform diagram corresponding to the pre-explosion test of the metal wire in the cubic specimen; Figure 5 Vibration waveform diagram corresponding to the three-dimensional mine seismic similarity simulation experiment of electric explosion of large metal wire; Figure 6 This is the vibration waveform diagram corresponding to the mechanical vibration source of the air hammer.

[0017] 1. High-voltage power supply; 2. Main discharge switch control unit; 3. Main discharge switch; 4. Current-limiting inductor; 5. Protective silicon stack and resistor unit; 6. Energy storage capacitor; 7. Manual discharge switch; 8. Discharge resistor unit. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention provides a simulation test system for the dynamic similarity of the internal seismic source of a mine earthquake based on the electric explosion of metal wire, comprising: a cabinet-type power supply host, a high-voltage circuit assembly disposed inside the cabinet-type power supply host, a high-voltage electrode assembly disposed outside the cabinet-type power supply host and connected to a similar material model, a host computer, an oscilloscope, and a similar material model.

[0020] The cabinet-type power supply unit adopts a movable insulated metal cabinet. The bottom of the cabinet is equipped with casters and a grounding lead-out terminal, and the front is equipped with an equipment door panel. When the door panel is closed, it forms a relatively independent high-voltage protection space.

[0021] The high-voltage circuit assembly includes a high-voltage power supply 1, a main discharge switch control unit 2, a main discharge switch 3, a current-limiting inductor 4, a protective silicon stack and resistor unit 5, an energy storage capacitor 6, a manual discharge switch 7, and a discharge resistor unit 8. The resistor unit includes a charging resistor and a protection resistor, and the discharge resistor unit 8 includes a normal discharge resistor and a discharge protection resistor.

[0022] like Figure 1 As shown, the high-voltage circuit assembly inside the cabinet-type power supply unit adopts a combination of top-bottom layering and left-right partitioning: the top is equipped with a high-voltage power supply 1 and its input interface, used to convert laboratory AC power into adjustable DC high voltage; the bottom of the top is equipped with a main discharge switch control unit 2, used to receive trigger signals from the host computer and output control commands to the main discharge switch 3; the upper middle part is equipped with the main discharge switch 3 and the main discharge high-voltage wire, used as the starting switching node for energy storage release; the middle part is equipped with a current-limiting inductor 4, connected in series in the main discharge branch to shorten the length of the high current channel; the lower middle part is equipped with a protection silicon stack, charging resistor, and protection resistor, so that the charging branch, main discharge branch, and discharge branch are structurally separated from each other; the bottom part is equipped with an energy storage capacitor 6 to meet the requirements of weight support and heat dissipation; the normal discharge resistor, discharge protection resistor, and manual discharge switch 7 are located near the energy storage capacitor 6 to shorten the length of the discharge branch; the bottom of the cabinet is equipped with high-voltage cables, grounding harnesses, and external connection interfaces.

[0023] like Figure 2 As shown, the high-voltage circuit assembly and the high-voltage electrode assembly form a charging branch, a main discharge branch, a discharge branch, and a detection branch.

[0024] A high-voltage power supply 1, a protection resistor, a protection silicon stack, a charging resistor, a freewheeling diode, and an energy storage capacitor 6 are connected in sequence to form a charging branch, which is used to limit the current charging of the energy storage capacitor 6 during the charging stage and block the reverse current to the high-voltage power supply 1 during the discharging stage.

[0025] The main discharge branch is formed by sequentially connecting the main discharge outlet of the energy storage capacitor 6, the main discharge switch control unit 2, the main discharge switch 3, the current limiting inductor 4, the high-voltage connector, the high-voltage electrode assembly, and the metal wire load. It is connected by a large-section high-voltage flexible cable and oriented along one side of the cabinet. This cable is used to quickly release the electrical energy in the energy storage capacitor 6 to the metal wire load after the discharge is triggered. The current limiting inductor 4 is connected in series in the main discharge circuit. By changing the inductance value and the equivalent impedance of the main discharge branch, the leading edge, peak occurrence time, and pulse width of the main discharge current are adjusted, so that the energy release characteristics of the internal seismic source of the model in a unit time are closer to those of the target prototype mine seismic event.

[0026] The high-voltage electrode assembly includes a first electrode, a second electrode, an insulating mounting base, clamping terminals, and two high-voltage cables extending from the cabinet-type power supply unit. The assembly relationship is as follows: the first and second electrodes are fixed to the insulating mounting base, which is then connected to a similar material model support plate or partial mounting component. The front ends of the first and second electrodes extend into the similar material model and are located at the target seismic source position. An adjustable gap is maintained between the two electrodes. A wire load is reliably crimped between the two electrodes via the clamping terminals. The two high-voltage cables are respectively connected to the rear connection terminals of the two electrodes. The wire load is a replaceable structure; therefore, after completing one test, only the wire needs to be replaced to ensure complete discharge before proceeding to the next test.

[0027] Fine copper wire is chosen for the metal wire load because it has stable conductivity, moderate heat of vaporization, low oxidation sensitivity, and can produce a relatively consistent explosion response in repeated tests. When the energy storage capacitor 6 completes charging and the host computer issues a trigger command, the main discharge switch 3 is turned on, generating a high-voltage pulse current in the main discharge branch. This current passes through the fine copper wire load in a very short time, causing it to rapidly undergo phase transitions from solid to liquid to gaseous to plasma states. During this process, the metal wire expands rapidly and exerts transient impacts on surrounding similar materials, creating localized stress waves and vibration disturbances, thus constructing an equivalent internal vibration source within the model.

[0028] The energy storage capacitor 6 is connected in parallel with a normal discharge resistor and a confirmatory discharge branch consisting of a manual discharge switch 7 and a discharge protection resistor connected in series. This discharge branch is used to further eliminate the residual high voltage of the energy storage capacitor 6 after the discharge is completed.

[0029] An oscilloscope and a current probe are connected to a high-voltage probe to form a detection branch. The current probe is located on the return side of the main discharge branch and is used to simultaneously acquire the discharge voltage waveform and the current waveform.

[0030] The host computer is connected to the cabinet-type power supply unit via a communication cable. The host computer software is configured with functions such as device parameter setting, device communication status display, charging start / stop, discharging trigger, fault alarm, waveform monitoring, and data retention. The host computer software interface includes at least a parameter setting area, a device status area, a control execution area, a real-time waveform area, a communication status area, and a data recording area. The parameter setting area is used to input information such as target charging voltage, energy storage level, trigger delay, and test number. The device status area is used to display communication status, charging status, waiting-to-trigger status, discharging status, and fault status. The control execution area is used to perform charging, stopping, discharging, and reset operations. The real-time waveform area is used to display voltage and current waveforms. The data recording area is used to save the timestamp, set parameters, and acquisition results for each test.

[0031] Specifically, such as Figure 3 As shown, the protection resistor R1 can be 1MΩ, the charging resistor R2 can be 500Ω, the normal discharge resistor R3 can be 40MΩ, the discharge protection resistor R4 can be 80kΩ, the protection silicon stack D1 and the freewheeling diode D2 can both be 20kV, 1A level devices, the energy storage capacitor 6 can be a 10kV, 100μF level capacitor, and the current limiting inductor 4 can be a 150mH level inductor. With the above device combination, approximately 5kJ of energy storage output can be achieved in a single test, and the rapid discharge conditions required for similar mine seismic tests can be met.

[0032] The working process of the charging branch, main discharge branch, bleedering branch, and detection branch is as follows: After the power supply in the laboratory is converted to DC high voltage by the high voltage power supply, it first enters the front protection section composed of the protection resistor R1 and the protection silicon stack D1, which is used to suppress abnormal impacts and protect the output of the high voltage power supply; then it enters the energy storage capacitor 6 through the charging resistor R2 and the freewheeling diode D2, and the energy storage capacitor 6 is charged with current limiting; the main discharge outlet of the energy storage capacitor 6 is connected in series with the main discharge switch 3 and the current limiting inductor 4, and then connected to the external electrode and the metal wire load through the high voltage probe P1 to form the main discharge branch; the energy storage capacitor 6 is connected in parallel with the normal discharge resistor R3 and the confirmatory discharge branch composed of the manual discharge switch 7 and the discharge protection resistor R4, which is used to further eliminate the residual high voltage after the discharge is completed; the current detection connector P2 is set on the return side of the main discharge branch, which is used to cooperate with the high voltage probe P1 to collect the discharge current waveform; the system common ground and the protection ground are grounded in the same way.

[0033] Based on the above-mentioned simulation test system, this disclosure provides a method for simulating the dynamic similarity of the internal seismic source of a mine earthquake based on the electric explosion of a metal wire, including: Step 1, Data Acquisition and Conversion: Collect seismic monitoring data of the target mine and convert the seismic monitoring data to determine the target charging voltage.

[0034] According to similarity theory, the energy similarity ratio between the model material and the prototype coal and rock is... α E The calculation formula is: (1); In the formula, α ρ This represents the density similarity ratio between the model material and the prototype coal and rock. α L This represents the geometric similarity ratio between the model material and the prototype coal and rock.

[0035] The theoretical energy storage calculation formula for energy storage capacitors is as follows: (2); In the formula, E c This represents the theoretical energy storage value of the energy storage capacitor. C This refers to the capacitance value of the energy storage capacitor. U This is the charging voltage.

[0036] In on-site mine seismic events, the effective energy actually used to generate propagable shock disturbances. E e Represented as: (3); In the formula, λ This is the energy transfer coefficient for the conversion of energy from a seismic event at the site into propagable shock waves and kinetic energy. It can be selected based on experience or calibration results, depending on the nature of the seismic event and the rock strata conditions. E s This refers to the energy generated by the on-site mine tremor event.

[0037] To consider the impact of the difference between the burial depth of the on-site seismic event and the burial depth of the model on energy propagation, a burial depth correction factor is introduced. η g The equivalent mechanical energy required by the earthquake source inside the model. E m The calculation formula is: (4); In the formula, η g To characterize the impact of the difference between the burial depth of the in-situ seismic event and the model burial depth on the effective energy propagation, when the in-situ seismic event has a large burial depth and strong confining pressure, η g The corresponding increase; when the model source is shallow, the surface scattering effect should be considered.

[0038] Define the mechanical impact energy actually converted during the airburst of a metal wire as: E k Then we have: (5); In the formula, P(t) This is a curve showing the change of shock wave pressure over time as measured by a pressure sensor. ρ k The air density in an airburst environment. v k The speed of sound in an airburst environment. S k This represents the equivalent wavefront area at the corresponding measurement point distance.

[0039] The energy conversion efficiency of an electrical explosion was obtained through an airburst calibration test. η c for: (6); Considering the energy conversion efficiency of an electric explosion η c Therefore, the required input electrical energy for the energy storage capacitor is: (7); In the formula, E c1 This refers to the input electrical energy that a capacitor should possess.

[0040] Through equation (7), the energy of the on-site seismic event is obtained. E s Inverse calculation model power supply setting energy storage E c1 Then, the charging voltage is determined by combining equation (2). U This ensures that the internal seismic sources in similar experiments correspond to the target prototype events in terms of energy level.

[0041] When the energy of a seismic event at the site is large, the charging voltage or equivalent capacitance can be increased first; when the energy of a seismic event at the site is small, the charging voltage can be appropriately reduced or the specifications of the fine copper wire can be changed. Through closed-loop correction of air-blast calibration, formal mold test, and waveform verification, the accuracy of energy conversion can be continuously improved.

[0042] Step 2, Device Initialization and Safety Confirmation: Check the insulation status of the cabinet-type power supply host, the system grounding status, the integrity of the high-voltage cable, the reset status of the main discharge switch, the effectiveness of the discharge circuit, the communication status of the host computer, and the oscilloscope connection status.

[0043] Step 3, Electrode Installation and Embedding of Wire Load Inside the Model: Fix the first and second electrodes at the target source position of the similar material model, bridge the pre-selected wire load, and confirm that the electrode spacing, wire load tension, and insulation conditions meet the test requirements.

[0044] Step 4, Inputting parameters and coordinating communication with the host computer: Input the simulation parameters into the host computer software and complete the communication confirmation. The simulation parameters include information such as target charging voltage, energy storage level, trigger delay, and test number.

[0045] Step 5, Low-energy pre-test and loop verification: Set a pre-charge voltage lower than the formal test value in the host computer software, perform pre-charge and pre-discharge, and verify the high-voltage probe, current detection connector, waveform display and circuit connectivity.

[0046] Step 6, Formal Charging and Discharging Trigger: Perform formal charging. When the system reaches the set voltage, it enters the waiting-to-trigger state. The host computer issues a trigger command to control the main discharge switch to turn on, so that the energy storage capacitor releases to the metal wire load inside the similar material model through the current-limiting inductor.

[0047] Step 7, Waveform Acquisition and Result Storage: Synchronously record voltage, current and required external response signals.

[0048] Step 8, Residual Voltage Discharge and Circuit Reset: After the discharge is completed, the residual energy is first released by the normal discharge branch, and then the manual discharge switch is operated for confirmation discharge. The load and electrodes can only be contacted after the capacitor residual voltage drops to a safe range.

[0049] Step 9, repeat the test or change the working conditions: change the wire specifications, adjust the voltage parameters or change the location of the seismic source according to the test plan, and continue to the next set of tests.

[0050] The above system and method were used to conduct a pre-experiment of electric explosion of a cubic metal wire specimen, a large-scale electric explosion experiment of a three-dimensional mine seismic simulation, and a comparative experiment of an air hammer mechanical source. The effectiveness of the method of the present invention was verified by combining the waveform results.

[0051] (1) Pre-experiment of electric explosion of metal wire in cubic specimen.

[0052] Experimental objective: To verify the feasibility of initiation of the electric explosion source of metal wire, the effect of internal slit formation in the specimen, and the collectability of vibration signals through pre-explosion tests on cubic specimens, so as to provide a basis for subsequent large-scale electric explosion experiments of metal wire in three-dimensional mine seismic simulation.

[0053] Experimental setup and procedure: A cubic similar specimen was used for the experiment. A metal wire was pre-embedded inside the specimen and connected to the high-voltage discharge circuit via a copper rod and a copper lug. A vibration sensor was fixed to the surface of the specimen with hot melt adhesive to collect the transient response signal caused by the electric explosion. The experimental procedure was as follows: the electric explosion system was charged → the rated voltage was reached → the discharge switch was triggered → the metal wire underwent an electric explosion → the discharge switch was pulled to release the residual electrical energy.

[0054] Experimental results: The vibration waveform corresponding to the pre-explosion test of the cubic specimen metal wire is shown in the figure. Figure 4 .

[0055] Result evaluation: by Figure 4 It is evident that a significant jump occurs in the initial stage of vibration, followed by a clear main peak and attenuation segment, indicating that the electrical explosion of the metal wire can generate effective dynamic disturbance within the specimen. The waveform exhibits good overall regularity, allowing for the identification of the main vibration stage and subsequent attenuation process. Furthermore, visible cracks form along the direction of the buried metal wire in the specimen after the pre-explosion, demonstrating that the source can both excite measurable vibration responses and produce concentrated destructive effects on the material's interior. Due to the small specimen size and boundary conditions, local peak values ​​are relatively sharp, and the subsequent attenuation segment is affected by certain boundary reflections; however, overall, the method meets the requirements for feasibility verification.

[0056] (2) Three-dimensional mine seismic similarity simulation of large metal wire electric explosion experiment.

[0057] Experimental objective: To verify the excitation capability of the internal seismic source of the metal wire electric explosion on the large-scale model in a three-dimensional mine seismic similarity simulation model, and to examine the similarity between the obtained waveform and the mine seismic waveform in the engineering field.

[0058] Experimental setup and procedure: Metal wires and copper rods are pre-embedded inside a three-dimensional similar material model. The exposed end of the copper rod is connected to a high-voltage discharge circuit via copper bolts. Vibration sensors are fixed on the model surface or at designated locations to form a complete excitation-monitoring system. In large-scale experiments, the metal wires are located inside the model, and the vibration source location is clearly defined, avoiding external interference caused by simple boundary excitation. The operation procedure is consistent with the preliminary experiment: charging the electro-explosion system → reaching the rated voltage → triggering the discharge switch → the metal wire undergoes an electro-explosion → pulling the discharge switch to release residual electrical energy.

[0059] Waveform results: The vibration waveforms corresponding to the three-dimensional mine seismic similarity simulation of the large metal wire electric explosion experiment are shown below. Figure 5 .

[0060] Result evaluation: Figure 5 It exhibits typical pulsed seismic signal characteristics. The waveform rapidly initiates oscillation within a very short time, followed by a distinct main peak and reverse peak. After the main oscillation ends, the signal rapidly decays and enters a relatively stable tailwave phase, with a clear overall structure and distinct layers. Compared with the transient release, peak concentration, and rapid decay characteristics commonly seen in mine seismic events in engineering fields, this waveform shows a high degree of similarity in time history. Since the seismic source is located inside the model, the vibration energy propagates from the inside out, which can well reflect the propagation mechanism of the internal seismic source. At the same time, the electrical explosion method has the characteristics of accurate triggering, controllable energy, and good repeatability, making it suitable for large-scale similarity simulation experiments.

[0061] (3) Comparison experiment of air hammer mechanical source.

[0062] Experimental objective: To conduct comparative experiments using an air hammer as a traditional mechanical seismic source, in order to compare the differences in waveform characteristics, noise levels, and similarity to mine seismic events among different source types.

[0063] Experimental setup and procedure: While maintaining essentially the same vibration monitoring methods, an air hammer was used to apply mechanical excitation and collect response signals for comparison with the internal seismic source of an electric explosion involving a metal wire. This type of seismic source is an external contact mechanical excitation, and its energy input method differs significantly from the transient release of an internal electric explosion. During the experiment, vibration sensors recorded the excitation response, and representative time-history waveforms were extracted for comparative analysis.

[0064] Waveform results: The vibration waveform corresponding to the mechanical source of the air hammer is shown below. Figure 6 .

[0065] Result evaluation: Figure 6 The vibrations are characterized by continuous, dense vibrations over a relatively long period, with an overall waveform exhibiting a noisy distribution. While there are local amplitude fluctuations, clear and prominent main peaks and attenuation boundaries are lacking. Compared to the waveform of an electric explosion from a metal wire, the energy input of a mechanical source is more dispersed, and background interference is stronger, making it difficult to accurately correspond to the dynamic characteristics of the instantaneous energy release within a mine seismic source. This result indicates that air hammers are more suitable as a general vibration excitation method than for high-fidelity simulation of internal seismic sources in mine seismic events.

[0066] right Figure 4 , Figure 5 and Figure 6 A comprehensive comparison shows that, Figure 4 The waveform of the electrical explosion of the metal wire in the large-scale similarity simulation experiment is most similar to that of the mine earthquake in the engineering field. This waveform has the characteristics of internal oscillation, concentrated peak, clear main oscillation segment, clear attenuation process and stable tail wave, which can well characterize the propagation response after the instantaneous release of energy inside the rock mass in the mine earthquake event. Figure 5 Although the corresponding preliminary experimental waveforms were more significantly affected by the specimen size and boundary conditions, they still exhibited relatively typical pulse start-up and attenuation patterns, indicating that the wire electro-explosion method is also effective under small-scale conditions. In contrast, Figure 6 The mechanical source waveform has a long duration, dense noise, and a lack of prominent main phase, making it difficult to reflect the essential characteristics of the internal source of a mine earthquake.

[0067] The present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A simulation test system for the internal dynamic source of mine earthquakes based on the electric explosion of metal wires, characterized in that, include: Cabinet-type power supply unit, high-voltage circuit components installed inside the cabinet-type power supply unit, high-voltage electrode components installed outside the cabinet-type power supply unit and connected to a similar material model, host computer, oscilloscope, and similar material model. The high-voltage circuit assembly includes a high-voltage power supply, a main discharge switch control unit, a main discharge switch, a current-limiting inductor, a protective silicon stack and resistor unit, an energy storage capacitor, a manual discharge switch and a discharge resistor unit. The resistor unit includes a charging resistor and a protection resistor, and the discharge resistor unit includes a normal discharge resistor and a discharge protection resistor. A high-voltage power supply, a protection resistor, a protection silicon stack, a charging resistor, a freewheeling diode, and an energy storage capacitor are connected in sequence to form a charging branch, which is used to limit the current charging of the energy storage capacitor during the charging stage and block the reverse current to the high-voltage power supply during the discharging stage. The main discharge outlet of the energy storage capacitor, the main discharge switch control unit, the main discharge switch, the current limiting inductor, the high voltage connector, the high voltage electrode assembly and the metal wire load are connected in sequence to form the main discharge branch, which is used to quickly release the electrical energy in the energy storage capacitor to the metal wire load after the discharge is triggered. The discharge branch consists of a normal discharge resistor connected in parallel across the energy storage capacitor and a confirmatory discharge branch consisting of a manual discharge switch and a discharge protection resistor connected in series. This branch is used to further eliminate the residual high voltage of the energy storage capacitor after the discharge is completed. The high-voltage electrode assembly includes a first electrode, a second electrode, an insulating fixing base, clamping terminals, and two high-voltage cables led out from the cabinet-type power supply host. The first electrode and the second electrode are fixed on the insulating fixing base, which is then connected to a similar material model support plate or a local mounting component. The front ends of the first electrode and the second electrode extend into the similar material model and are located at the target seismic source position. An adjustable gap is left between the two electrodes. The metal wire load is reliably crimped between the two electrodes through the clamping terminals. The two high-voltage cables are respectively connected to the rear connection terminals of the two electrodes. The host computer is connected to the cabinet-type power supply host via a communication cable. The host computer software is configured with functions such as device parameter setting, device communication status display, charging start / stop, discharge triggering, fault alarm, waveform monitoring, and data retention. An oscilloscope and a current probe are connected to a high-voltage probe to form a detection branch. The current probe is located on the return side of the main discharge branch and is used to simultaneously acquire the discharge voltage waveform and the current waveform.

2. The simulation test system for the internal dynamic source of mine earthquakes based on the electric explosion of metal wires according to claim 1, characterized in that, The metal wire load is made of fine copper wire.

3. The simulation test system for the internal seismic source dynamics of mine earthquakes based on the electric explosion of metal wires according to claim 1, characterized in that, The host computer's software interface includes at least a parameter setting area, a device status area, a control execution area, a real-time waveform area, a communication status area, and a data recording area. The parameter setting area is used to input information such as the target charging voltage, energy storage level, trigger delay, and test number. The device status area is used to display the communication status, charging status, waiting-to-trigger status, discharging status, and fault status. The control execution area is used to perform charging, stopping, discharging, and reset operations. The real-time waveform area is used to display voltage and current waveforms. The data recording area is used to save the timestamp, set parameters, and acquisition results for each test.

4. The simulation test system for the internal seismic source dynamics of mine earthquakes based on the electric explosion of metal wires according to claim 1, characterized in that, The cabinet-type power supply unit adopts an assembly method that combines upper and lower layers and left and right partitions: the top is equipped with a high-voltage power supply and its input interface, which is used to convert the laboratory AC power into adjustable DC high voltage; the bottom of the top is equipped with the main discharge switch control unit, which is used to receive the upper computer trigger signal and output control commands to the main discharge switch; the middle and upper part is equipped with the main discharge switch and the main discharge high voltage wire, which is used as the starting switching node for energy storage release. A current-limiting inductor is placed in the middle and connected in series in the main discharge branch to shorten the length of the high-current path. The lower middle section is equipped with a protective silicon stack, a charging resistor, and a protective resistor, which structurally separates the charging branch, the main discharge branch, and the discharge branch. The energy storage capacitor is arranged at the bottom; the normal discharge resistor, the discharge protection resistor, and the manual discharge switch are located near the energy storage capacitor; The bottom of the cabinet is equipped with high-voltage cables, grounding harnesses, and external connection interfaces.

5. The simulation test system for the internal seismic source dynamics of mine earthquakes based on the electrical explosion of metal wires according to claim 1, characterized in that, The cabinet-type power supply unit adopts a movable insulated metal cabinet, with casters and a grounding lead at the bottom of the cabinet, and an equipment door panel on the front.

6. A method for simulating the dynamic similarity of the internal seismic source in mine earthquakes based on the electric explosion of metal wires, characterized in that, The application of the dynamic similarity simulation test system for the internal seismic source of mine earthquakes based on the electric explosion of metal wires as described in any one of claims 1-5 includes: Step 1, Data Acquisition and Conversion: Collect seismic monitoring data of the target mine and convert the seismic monitoring data to determine the target charging voltage; Step 2, Device Initialization and Safety Confirmation: Check the insulation status of the cabinet-type power supply host, the system grounding status, the integrity of the high-voltage cable, the reset status of the main discharge switch, the effectiveness of the discharge circuit, the communication status of the host computer, and the connection status of the oscilloscope; Step 3, Electrode installation and wire load embedding inside the model: Fix the first and second electrodes at the target source position of the similar material model, bridge the wire load of the pre-selected specification, and confirm that the electrode spacing, wire load tension and insulation isolation conditions meet the test requirements. Step 4, Inputting parameters and coordinating communication with the host computer: Input the simulation parameters in the host computer software and complete the communication confirmation. The simulation parameters include information such as target charging voltage, energy storage level, trigger delay, and test number. Step 5, Low-energy pre-test and loop verification: Set a pre-charge voltage lower than the formal test value in the host computer software, perform pre-charge and pre-discharge, and verify the high-voltage probe, current detection connector, waveform display and circuit connectivity. Step 6, Formal charging and discharging trigger: Perform formal charging. When the system reaches the set voltage, it enters the waiting state. The host computer issues a trigger command to control the main discharge switch to turn on, so that the energy storage capacitor releases to the metal wire load inside the similar material model through the current limiting inductor. Step 7, Waveform Acquisition and Result Storage: Synchronously record voltage, current, and required external response signals; Step 8, residual voltage discharge and circuit reset: After the discharge is completed, the residual energy is first released by the normal discharge branch, and then the manual discharge switch is operated for confirmation discharge. The load and electrodes can only be contacted after the capacitor residual voltage drops to a safe range. Step 9, repeat the test or change the working conditions: change the wire specifications, adjust the voltage parameters or change the location of the seismic source according to the test plan, and continue to the next set of tests.

7. The method for simulating the dynamic similarity of the internal seismic source of a mine earthquake based on the electrical explosion of a metal wire, as described in claim 6, is characterized in that... Step 1 includes: According to similarity theory, the energy similarity ratio between the model material and the prototype coal and rock is... α E The calculation formula is: （1）； In the formula, α ρ This represents the density similarity ratio between the model material and the prototype coal and rock. α L This represents the geometric similarity ratio between the model material and the prototype coal and rock. The theoretical energy storage calculation formula for energy storage capacitors is as follows: （2）； In the formula, E c This represents the theoretical energy storage value of the energy storage capacitor. C This refers to the capacitance value of the energy storage capacitor. U This is the charging voltage; In on-site mine seismic events, the effective energy actually used to generate propagable shock disturbances. E e Represented as: （3）； In the formula, λ This represents the energy transfer coefficient for the conversion of energy from a seismic event at the site into a propagable shock wave and kinetic energy. E s Energy from on-site mine seismic events; To consider the impact of the difference between the burial depth of the on-site seismic event and the burial depth of the model on energy propagation, a burial depth correction factor is introduced. η g The equivalent mechanical energy required by the earthquake source inside the model. E m The calculation formula is: （4）； In the formula, η g This is used to characterize the corrective effect of the difference between the burial depth of the on-site seismic event and the model burial depth on the effective energy propagation; Define the mechanical impact energy actually converted during the airburst of a metal wire as: E k Then we have: （5）； In the formula, P(t) This is a curve showing the change of shock wave pressure over time as measured by a pressure sensor. ρ k The air density in an airburst environment. v k The speed of sound in an airburst environment. S k This represents the equivalent wavefront area at the corresponding measurement point distance; The energy conversion efficiency of an electrical explosion was obtained through an airburst calibration test. η c for: （6）； Considering the energy conversion efficiency of an electric explosion η c Therefore, the required input electrical energy for the energy storage capacitor is: （7）； In the formula, E c1 This refers to the input electrical energy that a capacitor should possess; Through equation (7), energy from on-site mine seismic monitoring E s Inverse calculation model power supply setting energy storage E c1 Then, the charging voltage is determined by combining equation (2). U This ensures that the internal seismic sources in similar experiments correspond to the target prototype events in terms of energy level.

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