A non-metallic mineral mining safety risk identification and early warning method

Abstract

The present application relates to the field of mine safety monitoring, and relates to a non-metallic mine exploitation safety risk identification and early warning method. The present application obtains the distribution of the rupture points of each microseismic event in a historical set time window, obtains the cumulative apparent volume of each sampling time point, analyzes the current cumulative damage acceleration index based on the cumulative apparent volume of each sampling time point; collects the displacement data of each measurement point along the hole depth of each drill hole of the roof to obtain the vertical displacement gradient of the roof, determines the spatial distribution plane, analyzes the spatial deflection change amount of the spatial distribution plane, constructs a multi-dimensional joint analysis state space in combination with the cumulative damage acceleration index, obtains the state point vector of each sampling time point, and analyzes the phase change discrimination boundary; determines the stability coefficient based on the seismic moment release rate sequence in the historical set time window, and corrects the phase change discrimination boundary; determines whether to perform early warning based on the current cumulative damage acceleration index and the spatial deflection change amount, and improves the timeliness and discrimination accuracy of early warning.

Description

Technical Field

[0001] This invention relates to the field of mine safety monitoring, and specifically to a method for identifying and warning of safety risks in non-metallic mineral mining. Background Technology

[0002] In the process of non-metallic mining, roof collapse, spalling, and roof fall are the most frequent and extremely dangerous geological safety hazards, which can easily cause equipment damage, casualties, and mining interruption. Traditional monitoring methods rely on a single indicator to judge risks, which makes it difficult to capture early warning information of rock mass failure. There are prominent problems such as delayed early warning and frequent missed alarms. The industry urgently needs a multi-parameter collaborative risk identification and early warning technology that can take into account both the evolution of internal micro-fractures and macro-roof deformation.

[0003] However, existing technologies have the following problems: 1. Most existing non-metallic mine roof safety monitoring methods rely only on a single physical quantity, such as displacement, or simply weight and fuse multiple parameters. They do not consider using the lead-lag phase relationship of displacement gradient tensor and cumulative apparent volume in time to capture the evolution process of rock mass failure, which makes it impossible to identify dangers when the displacement has not changed significantly.

[0004] 2. Existing technologies fuse microseismic parameters and displacement parameters using fixed weights or simple weighting methods. They do not consider the significant differences in the reliability and sensitivity of microseismic and displacement parameters at different damage evolution stages and under different rock mass fracture scale distribution states. They cannot dynamically adjust the early warning criteria based on the real-time stability of microseismic activity, and may falsely trigger early warnings due to microseismic noise. Summary of the Invention

[0005] This invention aims to address the shortcomings of existing technologies and provide a method for identifying and warning of safety risks in non-metallic mineral mining. This invention constructs a damage acceleration index by building a microseismic cumulative apparent volume and analyzes the spatial deflection changes by analyzing the roof displacement gradient, thus establishing a multi-dimensional state space. Combined with the seismic moment stability coefficient to correct the discrimination boundary, this achieves accurate and adaptive risk warning for the entire process of roof rock mass damage in non-metallic mineral mining.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The present invention provides a method for identifying and warning of safety risks in non-metallic mineral mining, comprising: acquiring the distribution of rupture points of each microseismic event within a historical set time window, acquiring the cumulative apparent volume at each sampling time point, and analyzing the current cumulative damage acceleration index based on the cumulative apparent volume at each sampling time point.

[0007] Displacement data of each measurement point along the hole depth of each borehole in the top plate are collected to obtain the vertical displacement gradient of the top plate. Based on the vertical displacement gradient of the top plate, the spatial distribution plane is determined, and the spatial deflection change of the spatial distribution plane is analyzed.

[0008] A multidimensional joint analysis state space is constructed based on the cumulative damage acceleration index and spatial deflection change, and the state point vectors at each sampling time point are obtained. The phase transition discrimination boundary is analyzed based on the state point vectors.

[0009] Obtain the seismic moment release rate sequence within a historical set time window, determine the stability coefficient based on the seismic moment release rate sequence, and correct the phase transition discrimination boundary based on the stability coefficient.

[0010] Based on the current cumulative damage acceleration index and spatial deflection change, and combined with the corrected phase transition discrimination boundary, it is determined whether to issue an early warning.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention obtains the distribution of rupture points of each microseismic event within a historical set time window, obtains the cumulative apparent volume of each sampling time point, and analyzes the current cumulative damage acceleration index based on the cumulative apparent volume of each sampling time point, so as to identify early deep damage precursors when the displacement has not changed significantly.

[0012] (2) This invention obtains the vertical displacement gradient of the top plate by collecting displacement data of each measurement point along the hole depth of each borehole in the top plate, determines the spatial distribution plane based on the vertical displacement gradient of the top plate, analyzes the spatial deflection change of the spatial distribution plane, upgrades the top plate deformation monitoring from single-point monitoring to full-domain spatial deformation analysis, accurately reflects the stress transfer and fracture propagation law, and improves the ability to identify the spatial characteristics of top plate deformation.

[0013] (3) Based on the cumulative damage acceleration index and spatial deflection change, the present invention constructs a multi-dimensional joint analysis state space, obtains the state point vector at each sampling time point, analyzes the phase transition discrimination boundary based on the state point vector, and jointly analyzes the micro-fracture evolution information and macro-deformation information in a unified state space, thereby improving the objectivity and comprehensiveness of instability precursor identification and effectively reducing missed alarms.

[0014] (4) This invention obtains the seismic moment release rate sequence within a historical set time window, determines the stability coefficient based on the seismic moment release rate sequence, and corrects the phase transition discrimination boundary based on the stability coefficient. It can dynamically adjust the early warning discrimination criteria according to the stability of real-time microseismic activity, effectively weaken the microseismic noise caused by external interference factors such as blasting and mechanical vibration, reduce the probability of false early warnings, and improve the environmental adaptability of the early warning system.

[0015] (5) Based on the current cumulative damage acceleration index and spatial deflection change, this invention determines whether to issue an early warning by combining the modified phase transformation discrimination boundary. It adapts to the sensitivity differences of the two types of monitoring indicators at different damage stages of the rock mass, takes into account both early micro-fracture identification and near-instability deformation capture, and improves the timeliness and discrimination accuracy of early warning of non-metallic mine roofs, ensuring the safe operation of personnel. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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.

[0017] Figure 1 This is a schematic diagram of the method steps of the present invention.

[0018] Figure 2 This is a schematic diagram illustrating the specific steps of the method for obtaining spatial deflection change in this invention.

[0019] Figure 3 This is a schematic diagram of the steps in the method for correcting the phase transition discrimination boundary in this invention. Detailed Implementation

[0020] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Furthermore, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale.

[0021] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0022] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0023] Please see Figure 1 As shown, the present invention provides a method for identifying and warning of safety risks in non-metallic mineral mining, including: S1, obtaining the cumulative apparent volume at each sampling time point and analyzing the current cumulative damage acceleration index.

[0024] Considering that deep microfractures in the roof of non-metallic mines occur earlier than visible surface displacement, relying solely on surface borehole displacement cannot predict instability risks in advance. While apparent volume can quantify the total inelastic damage to the rock mass in the seismic source area, directly accumulating the original apparent volume results in drastic fluctuations and fails to reflect the rate of damage evolution. By employing logarithmic transformation to compress the numerical span and then constructing a damage acceleration index using the average rate of change of adjacent time series, the interference of single microseismic disturbances can be weakened, accurately capturing the precursory characteristics of continuously accelerating damage within the rock mass, and achieving early identification of latent risks of instability.

[0025] Based on this, the specific implementation steps of S1 include: S11, obtaining the distribution of rupture points of each microseismic event within the historical set time window, and obtaining the cumulative apparent volume at each sampling time point. The specific implementation steps include: S111, obtaining the seismic moment and radiated energy of each microseismic event based on the elastic wave signals collected by the microseismic monitoring system, and calculating the apparent volume of each microseismic event based on the seismic moment and radiated energy. Preferably, the microseismic monitoring system includes several acceleration sensors installed in the roadway and roof surrounding rock, each sensor continuously collecting elastic wave signals at a sampling frequency of not less than 1 kHz. After sequentially performing bandpass filtering on the collected elastic wave signals, the local magnitude is calculated based on the maximum amplitude of the P-wave and S-wave, and then the seismic moment is converted; the radiated energy is calculated based on the energy integral of the elastic wave signal. In a specific embodiment of the present invention, the historical set time window is the past seven days, where each sampling time point is a fixed time point on each historical day, such as 8:00 AM; the implementer can also adjust it according to the actual situation.

[0026] The apparent volume mentioned here is an important parameter in microseismology characterizing the degree of inelastic deformation in the source region of a rock mass, representing the volume of the rock mass undergoing inelastic strain in the source radiation zone. Its specific calculation formula is as follows:

[0027] ;

[0028] in Represents seismic moment, Represents the source of earthquake radiation. This represents the shear modulus of the rock mass in the earthquake source region. This represents the apparent volume. The apparent volume is directly proportional to the square of the seismic moment and inversely proportional to the radiated energy and shear modulus. This formula is existing technology and will not be elaborated upon further in this invention.

[0029] S112. Obtain the sum of the apparent volumes of all microseismic events between each sampling time point and the first sampling time point within the historical set time window, and record it as the cumulative apparent volume of each sampling time point.

[0030] S12. Analyze the current cumulative damage acceleration index based on the cumulative apparent volume at each sampling time point. The specific implementation steps include: S121. Perform logarithmic calculation on the cumulative apparent volume at each sampling time point within the historical set time window to obtain the logarithmic domain cumulative apparent volume at each sampling time point within the historical set time window.

[0031] S122. Obtain the difference between the logarithmic cumulative apparent volume of each sampling time point and its adjacent previous sampling time point, and record the ratio of the difference to the logarithmic cumulative apparent volume of the adjacent previous sampling time point as the logarithmic cumulative apparent volume change rate.

[0032] S123. The weighted average of the logarithmic cumulative apparent volume change rate at each sampling time point within the historical set time window is recorded as the current cumulative damage acceleration index. In this embodiment, the weighted average of the logarithmic cumulative apparent volume change rate at each sampling time point is used as the current cumulative damage acceleration index.

[0033] Specifically, each sampling time point within the historical set time window is assigned a corresponding weight. For example, the number of days between each sampling time point and the current date is obtained, the sum of the number of days between each sampling time point and the current date is obtained, and the ratio of the number of days between each sampling time point and the sum of the number of days is recorded as the weight of the corresponding sampling time point. The cumulative apparent volume change rate in the logarithmic field of each sampling time point is weighted and summed according to the corresponding weight to obtain the current cumulative damage acceleration index.

[0034] This invention obtains the distribution of rupture points of each microseismic event within a historical set time window, acquires the cumulative apparent volume at each sampling time point, and analyzes the current cumulative damage acceleration index based on the cumulative apparent volume at each sampling time point, thereby enabling the identification of early precursors of deep damage when the displacement has not changed significantly.

[0035] S2. Collect displacement data of each measurement point along the hole depth of each borehole in the top plate to obtain the vertical displacement gradient of the top plate. Based on the vertical displacement gradient of the top plate, determine the spatial distribution plane and analyze the spatial deflection change of the spatial distribution plane.

[0036] Considering that single-point borehole displacement can only reflect local settlement and cannot characterize the overall tilting deformation caused by stress migration across the entire roof, and that the displacement differences at different borehole depths represent the stratification and displacement of rock layers, the introduction of a vertical displacement gradient can quantify the differences in vertical deformation of the rock layers. Therefore, by fitting a spatial distribution plane to a grid of multiple measuring points, and using both dip and azimuth deflections to describe the dynamic offset of the plane, the deformation distribution pattern across the entire roof can be fully restored, compensating for the deficiency of single-point monitoring in identifying large-scale spalling and collapse hazards.

[0037] Based on this, such as Figure 2As shown, the specific implementation steps of S2 include: S21, dividing the top plate into a grid, drilling holes at the intersections of each grid, and arranging multiple measuring points along the borehole axis at a set interval, and numbering each measuring point sequentially from the borehole opening to the bottom of the borehole. The closer to the borehole opening, the smaller the number. Furthermore, in this embodiment, preferably, the grid side length is set to 1m, and measuring points are arranged along the axial direction in each borehole at a interval of 0.5m. Multiple displacement gauges are installed at each measuring point, and displacement data of each measuring point is continuously collected at a sampling frequency of not less than 1 time / hour. The implementer can also set other specific values. The spatial deflection change includes the change in the tilt angle of the spatial distribution plane and the change in the tilt azimuth angle.

[0038] S22. Starting from the borehole opening, calculate step by step the displacement deviation and original depth difference of each measurement point in each borehole relative to its adjacent previous measurement point. Record the ratio of the displacement deviation to the original depth difference as the vertical displacement gradient of the corresponding measurement point. The adjacent previous measurement point refers to the measurement point corresponding to the next smaller number.

[0039] S23. Fit the spatial distribution plane based on the vertical displacement gradient of each measurement point in each borehole, and determine the inclination angle and tilt azimuth angle of the spatial distribution plane based on the normal vector of the spatial distribution plane. The specific implementation steps include: S231. Establish a spatial coordinate system with the horizontal plane as the XY plane and the vertical plane as the Z axis, obtain the measurement point with the largest absolute value of the vertical displacement gradient in each borehole, and record it as the reference point.

[0040] S232. Obtain the position coordinates of each reference point. Based on the position coordinates of the reference points of each borehole, fit the spatial distribution plane using the least squares method to obtain the normal vector of the spatial distribution plane. The acute angle formed by the normal vector and the Z-axis is denoted as the inclination angle of the spatial distribution plane. Specifically, first, set the equation of the spatial distribution plane, obtain the sum of squares of the distances from the position coordinates of each borehole's reference point to the set spatial distribution plane, and solve for the undetermined coefficients in the equation of the spatial distribution plane by minimizing the sum of squares. The process of solving for the coefficients is prior art and will not be described in detail in this invention.

[0041] S233. Obtain the projection of the normal vector onto the horizontal plane, and denote the angle formed by rotating it counterclockwise with the positive X-axis as the tilt azimuth angle of the spatial display plane.

[0042] S24. Obtain the difference between the tilt angle of the current spatial display plane and the tilt angle at the previous time point, and record it as the tilt angle change.

[0043] S25. Obtain the difference between the tilt azimuth angle of the current spatial distribution plane and the tilt azimuth angle of the previous time point, and record it as the tilt azimuth angle change. If there is no previous time point for a certain acquisition time point, record both the tilt angle change of the spatial distribution plane and the tilt azimuth angle change as 0.

[0044] This invention obtains the vertical displacement gradient of the top plate by collecting displacement data at each measurement point along the hole depth of each borehole. Based on the vertical displacement gradient of the top plate, it determines the spatial distribution plane and analyzes the spatial deflection change of the spatial distribution plane. This upgrades the monitoring of top plate deformation from single-point monitoring to full-domain spatial deformation analysis, accurately reflects the stress transfer and fracture propagation laws, and improves the ability to identify the spatial characteristics of top plate deformation.

[0045] S3. Construct a multi-dimensional joint analysis state space, obtain the state point vectors at each sampling time point, and analyze the phase transition discrimination boundary.

[0046] Considering the coupled correlation between the three types of indicators—accelerated microseismic damage, roof dip angle, and azimuth deflection—a single threshold can sever the coordinated instability of multiple parameters. By constructing a three-dimensional joint state space for the three types of indicators, the evolution trend of rock mass damage can be characterized by temporal vector changes. Relying on the historical vector magnitude and the statistical boundary of the deflection angle, the two types of states—stable deformation and abrupt phase transition—can be objectively distinguished, avoiding the problems of missed alarms and false alarms caused by artificially setting fixed thresholds.

[0047] Based on this, the specific implementation steps of S3 include: S31, constructing a multi-dimensional joint analysis state space based on the cumulative damage acceleration index and the spatial deflection change, and obtaining the state point vector at each sampling time point. The specific implementation steps include: S311, constructing a multi-dimensional joint analysis state space using the cumulative damage acceleration index as the first coordinate axis, the tilt angle change of the spatial distribution plane as the second coordinate axis, and the tilt azimuth angle change of the spatial distribution plane as the third coordinate axis.

[0048] S312. The cumulative damage acceleration index, the corresponding change in tilt angle and change in tilt azimuth angle of each sampling time point within the historical set time window are mapped to the multidimensional joint analysis state space to form a state point sequence.

[0049] S313. Obtain the state point coordinates of each sampling time point, and calculate the vector difference between them and the state point coordinates of the adjacent previous sampling time point to obtain the state point vector of each sampling time point.

[0050] S32. Phase transition discrimination boundary analysis based on state point vectors. For example... Figure 3 As shown, the specific implementation steps include: S321, obtaining the magnitude of the state point vector at each sampling time point within the historical set time window, obtaining the historical magnitude sequence, calculating the average and standard deviation of the historical magnitude sequence, and determining the initial magnitude threshold based on the average and standard deviation. Specifically, the sum of the average and three times the standard deviation is used as the initial magnitude threshold.

[0051] S322. Obtain the deflection angle between the state point vector of each sampling time point within the historical set time window and the state point vector of the previous sampling time point, construct a historical deflection angle sequence, obtain the mean and standard deviation of the historical deflection angle sequence, and determine the initial deflection angle threshold based on the mean and standard deviation. Use the sum of the mean and three times the standard deviation as the initial deflection angle threshold.

[0052] S323. Use the initial modulus threshold and the initial deflection angle threshold as the phase transition discrimination boundary.

[0053] This invention constructs a multi-dimensional joint analysis state space based on the cumulative damage acceleration index and spatial deflection change, obtains the state point vector at each sampling time point, analyzes the phase transition discrimination boundary based on the state point vector, and jointly analyzes the micro-fracture evolution information and macro-deformation information in a unified state space, thereby improving the objectivity and comprehensiveness of instability precursor identification and effectively reducing missed alarms.

[0054] S4. Determine the stability coefficient and correct the phase transition discrimination boundary.

[0055] Considering that mining blasting and mechanical operations generate a large number of interfering micro-seismic events, causing drastic fluctuations in the seismic moment release rate, fixed phase transition boundaries are prone to frequently triggering false warnings; the dispersion of the seismic moment release rate can quantify the stability of microseismic activity, thereby constructing a stability coefficient with dynamically scaling modulus and deflection angle dual thresholds. When the microseismic disturbance is severe, the judgment threshold is automatically raised, and the sensitive judgment standard is restored during the stable period, adaptively filtering out artificial vibration noise interference.

[0056] Based on this, the specific implementation steps of S4 include: S41, obtaining the seismic moment release rate sequence within a historical set time window, and determining the stability coefficient based on the seismic moment release rate sequence. Its specific implementation steps include: S411, obtaining the maximum amplitude of each microseismic event recorded by the monitoring system and calculating the local magnitude, and converting the corresponding seismic moment based on the local magnitude. Specifically, the calculation method of the seismic moment includes:

[0057] ;

[0058] in, Represents seismic moment, This represents the local magnitude. This formula is a classic moment-magnitude relationship in seismology and is an existing conversion technique, which will not be elaborated upon in this invention. The coefficients 1.5 and 9.1 are empirical values. Implementers can also recalibrate the values ​​of the coefficients based on historical earthquake data or microseismic monitoring data of the area where the mine is located, using regression analysis to adapt to the seismic wave attenuation characteristics of the local crustal medium.

[0059] S412. Obtain the sum of the seismic moments of each microseismic event between adjacent sampling time points, and record the ratio of this sum to the time interval between adjacent sampling time points as the seismic moment release rate.

[0060] S413. Obtain the standard deviation and average value of the seismic moment release rate within the historical set time window. The ratio of the difference between the current seismic moment release rate and the average value to the standard deviation is recorded as the stability coefficient. Preferably, when the number of sampling time points within the historical set time window is less than 3, the stability coefficient is set to a preset value of 1.0, and the phase transition discrimination boundary is not corrected temporarily until a sufficient number of sampling time points are accumulated.

[0061] S42. Correcting the phase transition discrimination boundary based on the stability coefficient. The specific implementation steps include: S421. Calculating the product of the stability coefficient and the initial modulus threshold, recording it as the correction amount of the initial modulus threshold, and recording the difference between the initial modulus threshold and the correction amount of the initial modulus threshold as the corrected modulus threshold.

[0062] S422. Calculate the product of the stability coefficient and the initial deflection angle threshold, and record it as the correction amount of the initial deflection angle threshold. Record the difference between the initial deflection angle threshold and the correction amount of the initial deflection angle threshold as the corrected deflection angle threshold.

[0063] S423. The modified modulus threshold and the modified deflection angle threshold are used to form the modified phase transition discrimination boundary.

[0064] This invention obtains the seismic moment release rate sequence within a historical set time window, determines the stability coefficient based on the seismic moment release rate sequence, and corrects the phase transition discrimination boundary based on the stability coefficient. It can dynamically adjust the early warning discrimination criteria according to the stability of real-time microseismic activity, effectively weaken the microseismic noise caused by external interference factors such as blasting and mechanical vibration, reduce the probability of false early warnings, and improve the environmental adaptability of the early warning system.

[0065] S5. Based on the current cumulative damage acceleration index and spatial deflection change, and combined with the corrected phase transition discrimination boundary, determine whether to issue an early warning.

[0066] Considering that rock masses will simultaneously exhibit two characteristics when they are about to collapse: accelerated internal damage and abrupt change in roof spatial deflection, satisfying only a single condition can easily lead to a delayed early warning. By simultaneously comparing the current state vector magnitude, deflection angle, and the dynamically corrected dual thresholds, an early warning is activated when any indicator exceeds the boundary. This approach takes into account both early signals of deep micro-fractures and macroscopic roof deformation characteristics, covering the entire cycle of rock mass instability precursors and improving the timeliness and accuracy of early warnings.

[0067] Based on this, the specific implementation steps of S5 include: S51, determining the current state point vector based on the current cumulative damage acceleration index and spatial deflection change, and obtaining the magnitude and deflection angle of the current state point vector.

[0068] S52. If the magnitude of the current state point vector is greater than the corrected magnitude threshold of the corrected phase transition discrimination boundary or the deflection angle is greater than the corrected deflection angle threshold in the corrected phase transition discrimination boundary, then an early warning is issued.

[0069] This invention determines whether to issue an early warning based on the current cumulative damage acceleration index and spatial deflection change, combined with the corrected phase transformation discrimination boundary. It adapts to the sensitivity differences of the two types of monitoring indicators at different damage stages of the rock mass, takes into account both early micro-fracture identification and near-instability deformation capture, and improves the timeliness and accuracy of early warning for non-metallic mine roofs, ensuring safe operation for personnel.

[0070] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0071] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0072] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0074] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for identifying and warning of safety risks in non-metallic mineral mining, characterized in that, include: Obtain the distribution of rupture points of each microseismic event within a historical set time window, obtain the cumulative apparent volume at each sampling time point, and analyze the current cumulative damage acceleration index based on the cumulative apparent volume at each sampling time point. The displacement data of each measurement point along the hole depth of each borehole in the top plate are collected to obtain the vertical displacement gradient of the top plate. Based on the vertical displacement gradient of the top plate, the spatial distribution plane is determined, and the spatial deflection change of the spatial distribution plane is analyzed. A multidimensional joint analysis state space is constructed based on the cumulative damage acceleration index and spatial deflection change, and the state point vectors at each sampling time point are obtained. The phase transition discrimination boundary is analyzed based on the state point vectors. Obtain the seismic moment release rate sequence within a historical set time window, determine the stability coefficient based on the seismic moment release rate sequence, and correct the phase transition discrimination boundary based on the stability coefficient. Based on the current cumulative damage acceleration index and spatial deflection change, and combined with the corrected phase transition discrimination boundary, it is determined whether to issue an early warning.

2. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 1, characterized in that, The method for obtaining the cumulative apparent volume at each sampling time point includes: The seismic moment and radiated energy of each microseismic event are obtained from the elastic wave signals collected by the microseismic monitoring system, and the apparent volume of each microseismic event is calculated based on the seismic moment and radiated energy. The sum of the apparent volumes of all microseismic events between each sampling time point and the first sampling time point within the historical set time window is obtained and recorded as the cumulative apparent volume of each sampling time point.

3. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 1, characterized in that, The analytical methods for the cumulative damage acceleration index include: Logarithmic calculations are performed on the cumulative apparent volume at each sampling time point within the historical set time window to obtain the logarithmic cumulative apparent volume at each sampling time point within the historical set time window. The difference between the logarithmic cumulative apparent volume at each sampling time point and its adjacent previous sampling time point is obtained, and the ratio of this difference to the logarithmic cumulative apparent volume at the adjacent previous sampling time point is denoted as the logarithmic cumulative apparent volume change rate. The weighted average of the logarithmic cumulative apparent volume change rate at each sampling time point within the historical set time window is recorded as the current cumulative damage acceleration index.

4. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 1, characterized in that, The spatial deflection change includes the change in the tilt angle and the change in the tilt azimuth angle of the spatial distribution plane. The method for obtaining the spatial deflection change includes: The top plate is divided into grids, and holes are drilled at the intersections of each grid. Multiple measuring points are set along the axis of the holes at a set interval, and each measuring point is numbered sequentially from the hole opening to the bottom of the hole. Starting from the borehole opening, the displacement deviation and original depth difference of each measurement point in each borehole and its adjacent previous numbered measurement point are calculated step by step. The ratio of the displacement deviation to the original depth difference is recorded as the vertical displacement gradient of the corresponding measurement point. The spatial distribution plane is fitted based on the vertical displacement gradient of each measurement point in each borehole, and the dip angle and tilt azimuth angle of the spatial distribution plane are determined based on the normal vector of the spatial distribution plane. Obtain the difference between the current spatial display plane tilt angle and its tilt angle at the previous time point, and record it as the tilt angle change. Obtain the difference between the tilt azimuth angle of the current spatial display plane and the tilt azimuth angle of the previous time point, and record it as the tilt azimuth angle change.

5. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 4, characterized in that, The methods for determining the inclination angle and tilt azimuth angle of the spatial layout plane include: A spatial coordinate system is established with the horizontal plane as the XY plane and the perpendicular plane to the horizontal plane as the Z axis. The measurement point with the largest absolute value of the vertical displacement gradient in each borehole is obtained and recorded as the reference point. Obtain the position coordinates of each reference point. Based on the position coordinates of the reference points of each borehole, fit the spatial distribution plane using the least squares method to obtain the normal vector of the spatial distribution plane. The acute angle between the normal vector and the Z-axis is recorded as the inclination angle of the spatial distribution plane. Obtain the projection of the normal vector onto the horizontal plane, and denote the angle formed by rotating it counterclockwise with the positive X-axis as the tilt azimuth angle of the spatial display plane.

6. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 5, characterized in that, The method for obtaining the state point vector at each sampling time point includes: Using the cumulative damage acceleration index as the first coordinate axis, the change in the tilt angle of the spatial distribution plane as the second coordinate axis, and the change in the tilt azimuth angle of the spatial distribution plane as the third coordinate axis, a multi-dimensional joint analysis state space is constructed. The cumulative damage acceleration index, the corresponding change in tilt angle and change in tilt azimuth angle of the spatial distribution plane at each sampling time point within the historical set time window are mapped to the multidimensional joint analysis state space to form a state point sequence. Obtain the state point coordinates at each sampling time point, and calculate the vector difference between them and the state point coordinates of the adjacent previous sampling time point to obtain the state point vector at each sampling time point.

7. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 1, characterized in that, The analysis method for the phase transition discrimination boundary includes: Obtain the magnitude of the state point vector at each sampling time point within the historical set time window, obtain the historical magnitude sequence, calculate the mean and standard deviation of the historical magnitude sequence, and determine the initial magnitude threshold based on the mean and standard deviation; Obtain the deflection angle between the state point vector of each sampling time point within the historical set time window and the state point vector of the previous sampling time point, construct a historical deflection angle sequence, obtain the mean and standard deviation of the historical deflection angle sequence, and determine the initial deflection angle threshold based on the mean and standard deviation; The initial modulus threshold and the initial deflection angle threshold are used as the phase transition discrimination boundary.

8. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 1, characterized in that, The analysis method for the stability coefficient includes: The maximum amplitude of each microseismic event recorded by the monitoring system is obtained and the local magnitude is calculated. The corresponding seismic moment is then calculated based on the local magnitude. The sum of the seismic moments of each microseismic event between adjacent sampling time points is obtained, and the ratio of this sum to the time interval between adjacent sampling time points is recorded as the seismic moment release rate. Obtain the standard deviation and average value of the seismic moment release rate within the historical set time window. The ratio of the difference between the current seismic moment release rate and the average value to the standard deviation is recorded as the stability coefficient.

9. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 8, characterized in that, The method for correcting the phase transition discrimination boundary includes: Calculate the product of the stability coefficient and the initial modulus threshold, and record it as the correction amount of the initial modulus threshold. Record the difference between the initial modulus threshold and the correction amount of the initial modulus threshold as the corrected modulus threshold. Calculate the product of the stability coefficient and the initial deflection angle threshold, and record it as the correction amount of the initial deflection angle threshold. Record the difference between the initial deflection angle threshold and the correction amount of the initial deflection angle threshold as the corrected deflection angle threshold. The modified modulus threshold and the modified deflection angle threshold are used to form the modified phase transition discrimination boundary.

10. The method for identifying and warning of safety risks in non-metallic mineral mining according to claim 9, characterized in that, The method for determining whether to issue a warning is as follows: The current state point vector is determined based on the current cumulative damage acceleration index and spatial deflection change, and the magnitude and deflection angle of the current state point vector are obtained. If the magnitude of the current state point vector is greater than the corrected magnitude threshold of the corrected phase transition discrimination boundary, or the deflection angle is greater than the corrected deflection angle threshold in the corrected phase transition discrimination boundary, an early warning will be issued.

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