Toppling deformable body fracture precursor identification method based on acoustic emission monitoring

Abstract

The invention provides a toppling deformation body fracture precursor identification method based on acoustic emission monitoring, which comprises the following steps: setting a monitoring area in a toppling deformation body, installing an acoustic emission sensor, and continuously monitoring the acoustic emission intensity by taking the time length t1 as a period. And establishing a relation equation between the acoustic emission intensity and the deformation, measuring the horizontal displacement of each point by using the total station, and calculating the deformation D of each point except the reference point. And converting the deformation D into acoustic emission frequency N and duration, drawing a correlation curve, and calculating a deformation speed v and a deformation speed change rate a. The fracture precursor or deformation body stability is judged according to indexes such as acoustic emission frequency, duration and progressive increase rate, and an early warning scheme is formulated and implemented according to the fracture precursor or deformation body stability. According to the invention, timeliness and reliability of geological disaster prevention can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological disaster monitoring and early warning, and more particularly, relates to a method for identifying precursory signs of a collapsing deformation body based on acoustic emission monitoring. BACKGROUND

[0002] In the field of geological disaster monitoring, stability analysis and precursory sign identification of a collapsing deformation body are key links to ensure public safety and reduce disaster losses. Traditional monitoring methods mainly rely on surface deformation observation, seismic activity monitoring, and geological structure analysis. These methods can provide information about the state of the deformation body to some extent, but have some limitations. For example, surface deformation observation can only reflect macroscopic displacement changes and is difficult to capture internal micro-fracture and deformation processes; seismic activity monitoring can detect larger seismic events, but is not sensitive to micro-fracture signals inside the collapsing deformation body; and geological structure analysis relies more on historical data and geological models and is difficult to reflect real-time dynamic changes.

[0003] With the development of sensor technology and signal processing technology, acoustic emission monitoring as a new monitoring method has gradually attracted attention. Acoustic emission refers to the elastic waves released by the internal micro-crack propagation or deformation process of an object under external force. By installing acoustic emission sensors inside or on the surface of the collapsing deformation body, these elastic wave signals can be monitored in real time, providing important basis for analyzing the internal state of the deformation body. However, existing acoustic emission monitoring technology still has deficiencies in identifying precursory signs of a collapsing deformation body. On the one hand, the complexity of acoustic emission signals makes it difficult to accurately establish the relationship between them and the internal physical processes of the deformation body; on the other hand, there is a lack of effective quantitative analysis methods to extract reliable precursory signs from a large amount of acoustic emission data.

[0004] In the process of implementing the embodiments of the present application, there are at least the following problems or defects in the prior art: First, the traditional monitoring method cannot reflect the development process of internal micro-fracture of the collapsing deformation body in real time and accurately; second, although the existing acoustic emission monitoring technology can detect acoustic emission signals, it lacks effective analysis models to quantitatively correlate acoustic emission signals with key parameters such as deformation and deformation speed of the deformation body; finally, the existing technology lacks clear judgment criteria and warning mechanisms when identifying precursory signs of a collapsing deformation body, making it difficult to issue warning signals in a timely and accurate manner to guide disaster prevention measures. SUMMARY

[0005] The present application provides a method for identifying precursory signs of a collapsing deformation body based on acoustic emission monitoring, comprising: Step 1: Set a monitoring area in the pouring deformation body, fix an acoustic emission sensor on one side or bottom edge of the pouring deformation body, monitor the acoustic emission intensity continuously for a monitoring period of time length t1; Step 2: Establish the relationship equation between the acoustic emission intensity and the deformation amount, take the top point A of the monitoring area as a reference point, measure the horizontal displacement amount of each point in the monitoring area by using a total station, and calculate the deformation amount D of each point except point A according to the acoustic emission intensity-deformation amount relationship equation; Step 3: Convert the deformation amount D into acoustic emission frequency N and duration , draw the acoustic emission frequency-time curve and the acoustic emission intensity-time curve; Step 4: Calculate the deformation velocity v and the deformation velocity change rate a; Step 5: Stability determination: When the conditions of: the deformation velocity v is unchanged or decreases, the deformation degree change rate decreases, the acoustic emission frequency increases, the acoustic emission duration increases, and the acoustic emission frequency increasing rate is greater than a threshold value , the acoustic emission duration increasing rate is greater than a threshold value , the deformation body is determined to be a precursor of rupture; When the conditions of: the deformation velocity v is unchanged or decreases, the deformation degree gradually decreases, the acoustic emission frequency gradually decreases, and the acoustic emission intensity gradually decreases, the deformation body is determined to be stable; Step 6: Develop a warning program according to the precursor of rupture and implement it.

[0006] Further, the calculation of the deformation amount D in step two comprises the following steps: Step 2.1: Measure the horizontal distance L between point M and the reference point A, point M being any point in the monitoring area; Step 2.2: Measure the included angle β between the line connecting point M and point A and the central axis; Step 2.3: Obtain the deformable angle θ recognizable by the monitoring system; Step 2.4: When θ is in the range of 0 degrees to 90 degrees, calculate the deformation amount D = L x sin β x tan θ; wherein L is the horizontal distance between point M and the reference point A, β is the included angle between the line connecting point M and point A and the central axis, and θ is the deformable angle recognizable by the monitoring system; Step 2.5: When θ is in the range of 90 degrees to 180 degrees, calculate the deformation amount D = L x sin β x |cot θ|; wherein L is the horizontal distance between point M and the reference point A, β is the included angle between the line connecting point M and point A and the central axis, and θ is the deformable angle recognizable by the monitoring system; Step 2.6: Determine the position point M' of point M after deformation according to D and θ.

[0007] Further, the relationship equation between the acoustic emission intensity and the deformation amount in step two is: S = K × [(1-2υ) / (1-υ)] Where: S is the acoustic emission intensity; K is the mass density of the rock material; υ is the Poisson's ratio of the rock material.

[0008] Furthermore, the calculation of the deformation rate v and the rate of change of deformation rate a in step four includes the following steps: Step 4.1: Obtain the displacements d1 and d2 corresponding to consecutive time points t1 and t2; Step 4.2: Calculate the deformation rate v = (d2 - d1) / (t2 - t1); where t1 and t2 are continuous time points, and d1 and d2 are the displacements at the corresponding time points; Step 4.3: Obtain the deformation velocities v3 and v4 corresponding to the consecutive time points t3 and t4; Step 4.4: Calculate the rate of change of deformation speed a = (v4 - v3) / (t4 - t3); where t3 and t4 are continuous time points, and v3 and v4 are the deformation speeds at the corresponding time points.

[0009] Furthermore, the formula for converting the deformation D into the acoustic emission frequency N in step three is as follows: N=C×D 2 Where C is the material conversion factor, with a value ranging from 0.5 to 1.2; and D is the deformation amount.

[0010] Furthermore, the duration described in step three The calculation method is as follows: Step 6.1: Define the monitoring interval T = t1 - t a , where t a To monitor the moment when the region boundary reaches the slip surface, t1 is the moment when it leaves the slip surface; Step 6.2: Sum the durations of all acoustic emission events within time period T. ; Step 6.3: Calculate the duration Where T is the monitoring interval, It represents the sum of the durations of all acoustic emission events within time period T.

[0011] Furthermore, the method for calculating the acoustic emission frequency increment rate in step five is as follows: Step 7.1: Obtain the acoustic emission frequencies N5 and N6 corresponding to consecutive time points t5 and t6; Step 7.2: Calculate the rate of change of frequency =(N6-N5) / (t6-t5); where t5 and t6 are consecutive time points, and N5 and N6 are the number of acoustic emission frequencies at the corresponding time points; Step 7.3: Obtain the frequency change rate corresponding to the continuous time points t7, t8 ; Step 7.4: Calculate the acoustic emission frequency increment rate ; wherein t7, t8 are continuous time points, is the frequency change rate at the corresponding time point.

[0012] Further, step five also includes critical state determination: Step 8.1: Calculate the acoustic emission frequency increment ΔN in unit time Δt; Step 8.2: When ΔN / Δt≥α×v, it is determined to enter the critical state; wherein α is the material critical coefficient, the value range is 1.5-2.0; v is the deformation speed; Δt is the unit time; ΔN is the acoustic emission frequency increment in unit time Δt; Start the three-level response under the critical state: First level: The data sampling frequency is increased to 1 time per minute; Second level: Start the UAV group to perform three-dimensional displacement scanning; Third level: Trigger the acousto-optic alarm and start the evacuation plan.

[0013] Further, the warning scheme in step six includes: Step 9.1: Establish an acoustic emission frequency growth model ; Step 9.2: Calculate the disaster occurrence time ; Wherein: is the current time, is the current acoustic emission frequency, β is the material rupture threshold, and k is the frequency growth coefficient; Step 9.3: Graded response: When >72 hours, issue a blue warning; When 24 hours ≤72 hours, issue a yellow warning; When ≤24 hours, issue a red warning and start full evacuation.

[0014] Further, it also includes a method for determining the deformable angle θ: Step 10.1: When point M is located on the collapse deformation surface, install an inclination sensor at point M; Step 10.2: Continuously measure the angle γ between the tangent plane at point M and the horizontal plane; Step 10.3: Calculate the deformable angle θ = 90° - |γ - γ0|; wherein γ is the angle between the tangent plane at point M and the horizontal plane, γ0 is the reference angle in the initial stable state, and θ is the deformable angle.

[0015] The above embodiments according to the present application have at least the following beneficial effects: 1. By setting a monitoring area in the dumping deformation body and installing an acoustic emission sensor, and combining the acoustic emission intensity with the deformation amount relationship equation, the development process of internal micro-cracks of the deformation body can be monitored in real time, and it is quantitatively associated with the macro-deformation amount, which solves the problems that the traditional monitoring method is difficult to capture internal micro-crack signals and cannot accurately establish the relationship between the acoustic emission signal and the internal physical process of the deformation body, and improves the accuracy and reliability of the cracking precursor identification of the dumping deformation body.

[0016] 2. The present application uses acoustic emission frequency, duration, deformation speed and its change rate and other multi-dimensional parameters to determine stability, which can comprehensively and dynamically reflect the deformation state of the dumping deformation body, avoids the misjudgment risk caused by single parameter determination, effectively solves the problem of lacking clear and reliable cracking precursor determination standard in the prior art, and provides a scientific basis for timely and accurate warning signals.

[0017] 3. Combined with the acoustic emission frequency growth model and disaster occurrence time prediction, a hierarchical warning response mechanism is established, which can take corresponding measures at different risk stages, such as increasing data sampling frequency, starting three-dimensional displacement scanning, triggering acoustic light alarm and starting evacuation plan, etc., which solves the problem of imperfect warning mechanism in the prior art, and improves the timeliness and effectiveness of geological disaster prevention. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other objects, features and advantages of the exemplary embodiments of the present application will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1 The flowchart of the dumping deformation body cracking precursor identification method based on acoustic emission monitoring provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] The technical solutions in the present application will be clearly and completely described below with reference to the drawings in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. It should be noted that: similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used for differentiation description, and cannot be understood as indicating or implying relative importance.

[0020] As shown in Figure 1 , the present application proposes a method for identifying the precursor of the rupture of the dumping deformation body based on acoustic emission monitoring, comprising the following steps: step 1: setting a monitoring area in the dumping deformation body, fixing the acoustic emission sensor on one side or the bottom of the dumping deformation body, taking the time length t1 as the monitoring period, and continuously monitoring the acoustic emission intensity; Step 2: establishing the relationship equation between acoustic emission intensity and deformation, taking the top point A of the monitoring area as the reference point, measuring the horizontal displacement of each point in the monitoring area by using the total station, and calculating the deformation D of each point except point A according to the acoustic emission intensity-deformation relationship equation; Step 3: converting the deformation D into acoustic emission frequency N and duration , drawing the acoustic emission frequency-time curve and the acoustic emission intensity-time curve; Step 4: calculating the deformation velocity v and the deformation velocity change rate a; Step 5: stability determination: When the conditions are met: the deformation velocity v is unchanged or reduced, the deformation degree change rate is reduced, the acoustic emission frequency is increased, the acoustic emission duration is increased, and the acoustic emission frequency incremental rate is greater than the threshold , the acoustic emission duration incremental rate is greater than the threshold , the deformation body is determined to be stable; When the conditions are met: the deformation velocity v is unchanged or reduced, the deformation degree gradually decreases, the acoustic emission frequency gradually decreases, and the acoustic emission intensity gradually decreases, the deformation body is determined to be stable; Step 6: developing an early warning scheme according to the precursor of the rupture and implementing it.

[0021] The acoustic emission sensor refers to a device for detecting elastic waves generated by micro-cracks inside or on the surface of the dumping deformation body, and can be specifically implemented by a piezoelectric sensor or an optical fiber sensor to realize real-time monitoring of the internal state of the deformation body by capturing elastic wave signals. The monitoring period refers to the time period for continuously collecting acoustic emission signals, which can be specifically implemented by using a fixed time window or dynamically adjusting the time interval to ensure the continuity and timeliness of data collection. The relationship equation between acoustic emission intensity and deformation amount refers to the correlation between acoustic emission signal intensity and physical deformation amount through a mathematical model, which can be specifically implemented by using a linear equation based on the Poisson's ratio and mass density of rock materials to provide a calculation basis for quantitative analysis of deformation amount. The horizontal displacement amount refers to the position change amount of the monitoring point relative to the reference point in the horizontal direction, which can be specifically measured by a total station or a laser range finder to verify the corresponding relationship between acoustic emission data and physical deformation. The acoustic emission frequency refers to the number of acoustic emission events detected per unit time, which can be specifically implemented by counting and counting the original waveform through a signal processing algorithm to reflect the frequency of internal cracking activities of the deformation body. The deformation velocity refers to the rate of change of displacement amount with time, which can be specifically implemented by calculating the displacement difference between adjacent time points through difference calculation to evaluate the dynamic trend of deformation development. The deformation velocity change rate refers to the acceleration index of deformation velocity, which can be specifically implemented by calculating the velocity difference through the second difference method to identify the nonlinear characteristics of the deformation process. The stability determination condition refers to the logical combination based on acoustic emission frequency, duration and deformation parameters, which can be specifically implemented by using threshold comparison and trend analysis algorithm to establish a criterion system of multi-parameter fusion.

[0022] The core innovation of the present application lies in establishing a quantitative relationship model between acoustic emission signals and deformation parameters, combining dynamic monitoring data of deformation velocity, frequency growth rate and duration change, constructing a multi-dimensional criterion system, realizing accurate identification of cracking precursors of dumping deformation body and real-time determination of stability state, and realizing prediction of disaster occurrence time through early warning time calculation model, forming a complete monitoring-analysis-warning technology chain.

[0023] The working process and principle of the present application are as follows: a monitoring area is set in the dumping deformation body, and the acoustic emission sensor is fixed to one side or the bottom of the dumping deformation body. The monitoring period is time length t1, and the acoustic emission intensity is continuously monitored. This arrangement can comprehensively capture the acoustic emission signals inside the deformation body.

[0024] A relationship equation between acoustic emission intensity and deformation amount is established. Point A at the top of the monitoring area is taken as a reference point, and the horizontal displacement amount of each point in the monitoring area is measured by a total station. The deformation amount D of each point except point A is calculated according to the relationship equation between acoustic emission intensity and deformation amount. This step realizes the quantitative correlation between acoustic emission signals and actual deformation amount.

[0025] Convert the deformation D into acoustic emission frequency N and duration Draw the acoustic emission frequency curve and acoustic emission intensity curve over time. This conversion establishes a direct mathematical relationship between acoustic emission parameters and deformation.

[0026] Calculate the deformation velocity v and the deformation velocity change rate a. These two parameters reflect the dynamic change process of the deformation body.

[0027] Make a stability determination. When the following conditions are met, it is determined to be a precursor to rupture: the deformation velocity v is constant or decreases, the deformation degree change rate decreases, the acoustic emission frequency increases, the acoustic emission duration increases, and the acoustic emission frequency incremental rate is greater than the threshold , the acoustic emission duration incremental rate is greater than the threshold When the following conditions are met, the deformation body is determined to be stable: the deformation velocity v is constant or decreases, the deformation degree gradually decreases, the acoustic emission frequency gradually decreases, and the acoustic emission intensity gradually decreases. This multi-parameter coupled determination method improves the accuracy of the identification of rupture precursors.

[0028] Develop a warning plan according to the rupture precursor and implement it. This step converts the monitoring results into actual disaster prevention and mitigation measures.

[0029] As a preferred embodiment, the scheme of the present application is implemented as follows: In a certain mountain landslide monitoring project, a place of toppling deformation body is selected as the monitoring object. Five acoustic emission sensors are installed at the bottom edge of the deformation body, uniformly distributed in a linear manner. The monitoring period is set to 24 hours, and the sampling frequency is 100 kHz.

[0030] Establish the relationship equation between acoustic emission intensity and deformation: S=K×[(1-2υ) / (1-υ)], where K is the mass density of rock material, and υ is the Poisson's ratio of rock material. Through experiments, K=2.7 g / cm 3 , υ=0.25.

[0031] Use a total station to measure the horizontal displacement of 10 key points in the monitoring area. Calculate the deformation D of these points according to the relationship equation.

[0032] Convert the deformation D into acoustic emission frequency N: N=C×D 2 , where C is 0.8. Calculate the duration . Draw the acoustic emission frequency and intensity change curve within 24 hours.

[0033] Calculate the deformation velocity v and the deformation velocity change rate a every hour.

[0034] Set the determination threshold: =0.5 times / hour2 , = 0.2 seconds / hour 2 When the monitoring data meets the pre-fracture condition, the system automatically sends a warning signal.

[0035] According to the warning level, the corresponding emergency plan is formulated, including increasing the monitoring frequency, starting the unmanned aerial vehicle patrol, evacuating the surrounding residents and other measures.

[0036] In some of the above schemes of the application, the deformation of each point is calculated by the relationship equation of acoustic emission intensity and deformation, however, in the calculation process, due to the difference of geometric relationship of different position points and the influence of deformable angle, the calculation result of deformation may not be accurate enough, and then the determination of the position after deformation is affected.

[0037] The application further selects an arbitrary point M in the monitoring area, measures the horizontal distance L between the point M and the reference point A, measures the included angle β of the line connecting the point M and the point A and the central axis, obtains the deformable angle θ recognizable by the monitoring system, selects different calculation formulas according to the range of θ: when θ is between 0 degrees and 90 degrees, the deformation D is calculated by L*sinβ*tanθ; when θ is between 90 degrees and 180 degrees, the deformation D is calculated by L*sinβ*|cotθ|, and finally the position of the point M after deformation M' is determined.

[0038] Among them, the horizontal distance L is measured by the total station, the included angle β is obtained by the angle sensor or the total station, and the deformable angle θ is obtained by continuously measuring the included angle γ of the tangent plane of the point M and the horizontal plane by the inclination sensor and combining the initial reference included angle γ 0 When θ is in different ranges, the deformation is calculated by using a piecewise function respectively, so as to avoid the divergence problem of tangent or cotangent function caused by the change of angle. For example, when θ is close to 90 degrees, tanθ tends to infinity, at this time, the influence of the deformable angle is calculated by using the cotangent function, and the absolute value processing is used to ensure that the deformation is always positive.

[0039] Specifically, the included angle γ of the tangent plane of the point M and the horizontal plane is measured by the inclination sensor in real time, and the initial reference included angle γ is combined to calculate the deformable angle When θ is between 0 degrees and 90 degrees, it indicates that the deformation body is in the elastic deformation stage, at this time, the deformation D and tanθ are in linear relationship; when θ exceeds 90 degrees, it indicates that the deformation body enters the plastic deformation or critical failure stage, at this time, the deformation is calculated by using the cotangent function, so as to avoid the calculation error caused by the sudden change of angle. By using the piecewise calculation method, the change of geometric relationship in different deformation stages is accurately reflected, and combined with the horizontal displacement measurement data, the position of the point M after deformation M' is finally determined, which provides accurate input for the conversion of subsequent acoustic emission frequency and duration.

[0040] As a preferred embodiment, the scheme of the present application is implemented as follows: In the monitoring process of the dumping deformation body, first, a monitoring area is set in the dumping deformation body, and an acoustic emission sensor is fixed to one side of the dumping deformation body. A point A at the top of the monitoring area is selected as a reference point, and a total station instrument is used to measure the horizontal displacement of each point in the monitoring area.

[0041] Taking a point M in the monitoring area as an example, the horizontal distance L between the point M and the reference point A is 50 meters. The included angle β between the line connecting the point M and the point A and the central axis is 30 degrees, which is measured by the total station instrument. According to the setting of the monitoring system, the identifiable deformable angle θ is 45 degrees.

[0042] Since θ is in the range of 0 degrees to 90 degrees, the deformation D is calculated by the formula D=L×sinβ×tanθ. The numerical value is substituted into the formula: D=50 meters×sin30°×tan45°≈12.5 meters According to the calculated deformation D and the known deformable angle θ, the position of the point M after deformation M' is determined. By this method, the deformation of each point in the monitoring area can be accurately calculated, thereby providing basic data for subsequent acoustic emission intensity analysis and rupture precursor identification.

[0043] Through the above technical scheme, the present application realizes accurate calculation of the deformation of each point inside the dumping deformation body. By establishing a correlation between the acoustic emission intensity and the deformation, the interpretability of the acoustic emission monitoring data is improved. This method overcomes the limitation that the traditional monitoring method cannot accurately reflect the internal micro-deformation, and provides more reliable data support for the stability analysis and rupture precursor identification of the dumping deformation body.

[0044] In some schemes of the present application, a relationship equation between acoustic emission intensity and deformation is proposed to correlate the acoustic emission signal with the physical parameters of the deformation body. However, in this process, there is a lack of quantitative expression of the physical properties of the rock material itself, which leads to the fact that the mathematical relationship between the acoustic emission intensity and the deformation cannot accurately reflect the stress distribution characteristics inside the material, thereby affecting the accuracy of the deformation calculation.

[0045] The present application further proposes a relationship equation between acoustic emission intensity and deformation as follows: S=K×[(1-2υ) / (1-υ)], wherein S is the acoustic emission intensity, K is the mass density of the rock material, and υ is the Poisson's ratio of the rock material.

[0046] In the equation, two material parameters, mass density and Poisson's ratio, are introduced to establish a direct correlation between the stress state inside the material and the acoustic emission intensity. The mass density K is a basic property of the material, and its value range varies according to the type of rock, for example, the K value of granite is usually in the range of 2.6-2.8 g / cm 32.2-2.5g / cm 3 The value of Poisson's ratio u is measured by laboratory compression test, and the value of common rock is in the range of 0.2-0.35. The term (1-2u) / (1-u) in the equation reflects the ratio of volume change to axial strain during deformation, which presents a nonlinear change with the increase of Poisson's ratio, and the ratio tends to zero when u tends to 0.5, corresponding to the material entering the plastic deformation stage.

[0047] Specifically, after the monitoring system obtains the acoustic emission intensity data, the stress state corresponding to the deformation amount can be reversely deduced by the equation. Taking granite as an example, when the measured acoustic emission intensity S is 120 event times / minute, substituting K=2.7g / cm 3 and u=0.28, (1-2u) / (1-u)=0.44 / (0.72)=0.611 is calculated, and at this time the deformation amount parameter can be calculated by the deformation amount equation. The equation integrates the material constitutive relation into acoustic emission analysis, so that the acoustic emission intensity data can be directly converted into a quantitative index representing the stability of the deformation body, solving the problem that the acoustic emission signal is disconnected with the physical deformation in the traditional method. When the Poisson's ratio changes by 0.01 magnitude, the relative change of the equation output value can reach 3.5%, and this sensitivity ensures that the monitoring system can capture the small changes of the mechanical properties of the material.

[0048] As a preferred embodiment, the scheme of the application is implemented as follows: In the monitoring of the dumping deformation body, the relationship equation between acoustic emission intensity and deformation amount is: S=K×[(1-2u) / (1-u)] Wherein, S represents the acoustic emission intensity; K represents the mass density of rock material; u represents the Poisson's ratio of rock material.

[0049] For example, for a granite dumping deformation body, the mass density K is 2.7g / cm 3 , and the Poisson's ratio u is 0.25. Substituting these parameters into the relationship equation, we can get: S=2.7×[(1-2×0.25) / (1-0.25)]=2.7×0.67=1.81 This means that in the granite dumping deformation body, when the acoustic emission intensity reaches 1.81 event times / minute or the corresponding energy unit, it may correspond to a significant deformation amount.

[0050] Further, by continuously monitoring the change of acoustic emission intensity S, the dynamic change process of deformation amount can be inferred. For example, if it is observed that the S value rises from 1.81 to 2.72, it may indicate that the deformation amount increases by 50%. Thus, the stability state of the dumping deformation body can be evaluated in real time.

[0051] In some of the above schemes of the present application, a method for calculating the deformation of each point by the relationship equation between acoustic emission intensity and deformation is proposed. However, in the calculation of deformation velocity and deformation velocity change rate, the prior art lacks specific calculation steps and parameter acquisition methods, which leads to the inability to accurately quantify the deformation dynamic process and makes it difficult to judge whether the deformed body is in an accelerated instability state.

[0052] The present application further proposes a method for calculating the deformation velocity v and the deformation velocity change rate a, which comprises the following steps: obtaining the displacement amounts d1 and d2 corresponding to the continuous time points t1 and t2; calculating the deformation velocity v=(d2-d1) / (t2-t1); obtaining the deformation velocities v3 and v4 corresponding to the continuous time points t3 and t4; and calculating the deformation velocity change rate a=(v4-v3) / (t4-t3).

[0053] The calculation of the deformation velocity is achieved by dividing the displacement difference of two continuous time points by the time interval. The selection of the time points needs to meet the condition of equal interval, for example, collecting displacement data every 5 minutes or 10 minutes. The calculation of the deformation velocity change rate further selects the velocity values of the subsequent two continuous time points for difference processing, forming an acceleration parameter in the form of second derivative. The displacement amount needs to be measured by a total station with millimeter-level precision to ensure that the data error is controlled within 0.1 millimeter.

[0054] Specifically, after measuring the displacement amount d1 at t1, the displacement amount d2 is measured at t after a fixed time interval Δt, such as 10 minutes, and the average deformation velocity is calculated by linear difference. This velocity value is recorded as v1, and then v2 is measured at the next time interval, and the deformation velocity change rate is obtained by (v2-v1) / Δt. For example, when Δt is 10 minutes, if v1 is 0.5 millimeter / minute and v2 is 0.8 millimeter / minute, then the change rate a is 0.03 millimeter / minute 2 This step-by-step calculation method can effectively distinguish the stage characteristics of velocity change and avoid the influence of single measurement error on the overall trend judgment.

[0055] As a preferred embodiment, the scheme of the present application is implemented as follows: The method for calculating the deformation velocity v and the deformation velocity change rate a comprises the following steps: Obtaining the displacement amounts d1 and d2 corresponding to the continuous time points t1 and t2. For example, in the monitoring of a certain toppling deformation body, t1 is 12:00:00 on May 1, 2023, t2 is 12:30:00 on May 1, 2023, and the corresponding displacement amounts d1 and d2 are 5.2 mm and 6.8 mm, respectively.

[0056] The deformation velocity v is calculated as (d2-d1) / (t2-t1). Specifically, v=(6.8mm-5.2mm) / (0.5h)=3.2mm / h.

[0057] The deformation velocities v3 and v4 corresponding to the continuous time points t3 and t4 are obtained. Further, it is assumed that t3 is 13:00:00 on May 1, 2023, t4 is 13:30:00 on May 1, 2023, the corresponding deformation velocities v3 and v4 are 3.2mm / h and 3.6mm / h respectively.

[0058] The change rate a of the deformation velocity is calculated as (v4-v3) / (t4-t3).

[0059] Thus, a=(3.6mm / h-3.2mm / h) / (0.5h)=0.8mm / h 2 .

[0060] In some of the above schemes of the present application, the deformation is calculated by the relationship equation between acoustic emission intensity and deformation, and the deformation is further converted into acoustic emission frequency and duration to analyze the deformation state. However, the conversion relationship between deformation and acoustic emission frequency lacks clear mathematical correlation, resulting in insufficient frequency calculation accuracy and affecting the reliability of the pre-fracture identification.

[0061] The present application further proposes a calculation formula for converting the deformation into the acoustic emission frequency N equals to C multiplied by the square of D, wherein C is a material conversion coefficient, and the value range is 0.5 to 1.2, and D is the deformation.

[0062] The value of the material conversion coefficient C is determined according to the rock type and structural characteristics, for example, 0.8 for granite and 1.0 for shale. The square relationship of the deformation D reflects the nonlinear growth characteristics of the acoustic emission events with the deformation degree. The numerical range of the coefficient C is calibrated by experiments. When C is lower than 0.5, the calculation result underestimates the actual acoustic emission activity; when C exceeds 1.2, false alarms may be generated.

[0063] Specifically, after obtaining the deformation D of each monitoring point, the square value of D is multiplied by the material conversion coefficient C to obtain the value of the acoustic emission frequency N. The calculation process is embedded in the data processing module of the monitoring system, and the frequency data is output in real time for drawing the change curve. The introduction of the square relationship forms a quadratic function relationship between the acoustic emission frequency and the deformation, which is more consistent with the acceleration characteristics of energy release in the rock fracture process. For example, when the deformation reaches 2mm, if C is 1.0, the calculated frequency is 4 times per minute; when the deformation increases to 3mm, the frequency rises to 9 times per minute, effectively amplifying the influence of small deformation on acoustic emission activity and improving the identification sensitivity of the pre-fracture.

[0064] As a preferred embodiment, the scheme of the present application is implemented as follows: In converting the deformation amount D into the acoustic emission frequency N, the following calculation formula is adopted: N=CxD 2 Wherein C is the material conversion coefficient, the value range is 0.5-1.2; D is the deformation amount.

[0065] Specifically, for different rock materials, the corresponding material conversion coefficient C can be determined through experiments. For example, for granite, C can be taken as 0.8; for sandstone, C can be taken as 1.0; for shale, C can be taken as 0.6.

[0066] In practical application, first, the deformation amount D is calculated according to the method in step 2. Then, the appropriate material conversion coefficient C is selected according to the rock type of the monitoring area. Finally, D and C are substituted into the formula N=CxD 2 , and the corresponding acoustic emission frequency N can be obtained.

[0067] Further, the acoustic emission frequency at different time points can be calculated continuously, and the curve of acoustic emission frequency changing with time can be drawn, which is used for subsequent stability judgment and pre-failure identification.

[0068] In some schemes of the present application, a method of analyzing the deformation body state through acoustic emission frequency and duration is proposed. However, in calculating the acoustic emission duration, the traditional method only focuses on the duration of a single event, lacks quantitative evaluation of the continuity of acoustic emission activity in the whole monitoring period, and cannot accurately reflect the cumulative effect of the internal rupture process of the deformation body.

[0069] The present application further proposes a calculation method of duration , which comprises the following steps: defining the monitoring interval T as the difference between t a , wherein t a is the time when the boundary of the monitoring area reaches the slip surface, and t1 is the time when the slip surface is left; accumulating the total duration sum Σδt of all acoustic emission events in the period T; calculating the duration as the ratio of Σδt to T.

[0070] Wherein, the determination of the monitoring interval T depends on the accurate measurement of the arrival and departure time of the slip surface boundary, which is realized by displacement sensor or image recognition technology; the total duration sum Σδt is obtained by accumulating the timestamp data of acoustic emission signals, for example, using a high-precision timer to record the start and end time of each acoustic emission event; the duration is calculated by normalizing the total duration and the monitoring interval, which eliminates the influence of the length of the time window on the result.

[0071] Specifically, the monitoring interval T is divided based on the dynamic changes of the slip surface boundary, ensuring a strict correspondence between the analysis period and the actual activity stage of the deformed body. When Σδt is accumulated, an event-driven data acquisition method is used to avoid missing short-duration, high-frequency acoustic emission events. The calculation integrates the duration of discrete acoustic emission events into a continuous index, for example, when T is 60 minutes and Σδt is 120 seconds. The frequency emission rate is 2 seconds per minute, reflecting the persistence level of acoustic emission activity per unit time. When analyzed in conjunction with deformation rate and frequency change rate, this index can more sensitively capture the critical state of internal fracture accumulation in deformable bodies, for example... A sudden increase in [something] may indicate the penetration of microcracks.

[0072] As a preferred embodiment, the solution of this application is specifically implemented as follows: In the monitoring of toppled deformed bodies, the monitoring interval T is defined as the time t from the boundary of the monitoring area to the slip surface. a The time interval T is the period between the arrival of the monitoring area boundary at the slip surface and the departure of the slip surface at 10:00. For example, if the monitoring area boundary arrives at the slip surface at 10:00 and leaves the slip surface at 10:30, then the monitoring interval T is 30 minutes.

[0073] During the 30-minute monitoring interval, the acoustic emission monitoring system continuously records all acoustic emission events. Each acoustic emission event has a duration δt. Assume that a total of 100 acoustic emission events are recorded during these 30 minutes, with each event having a duration of 0.5 seconds, 0.7 seconds, 0.3 seconds, etc.

[0074] Furthermore, the durations of these 100 acoustic emission events are summed to obtain Σδt. For example, the total duration Σδt after summing is 60 seconds.

[0075] Therefore, the duration is calculated. =Σδt / T=60 seconds / 1800 seconds=0.033. This value represents the proportion of time occupied by acoustic emission events within the entire monitoring interval.

[0076] In some of the solutions described above in this application, a criterion for judging the precursor of a rupture is proposed by using the acoustic emission frequency increase rate. However, in the actual implementation process, due to the lack of a clear method for calculating the acoustic emission frequency increase rate, it is impossible to accurately quantify the changing trend of the acoustic emission frequency, which in turn affects the accuracy of the stability determination.

[0077] This application further proposes a method for calculating the acoustic emission frequency increment rate, comprising the following steps: obtaining the acoustic emission frequency frequencies corresponding to consecutive time points; calculating the frequency change rate; obtaining the frequency change rate corresponding to consecutive time points; and calculating the acoustic emission frequency increment rate.

[0078] Wherein, the acoustic emission frequency of continuous time points is obtained by using a fixed time interval data acquisition method, ensuring the continuity of time series data. The frequency change rate is calculated by using the difference method, and the instantaneous change rate is obtained by dividing the frequency difference of adjacent time points by the time interval. The acoustic emission frequency increase rate is further calculated by twice differentiating the frequency change rate, forming a quantitative indicator of the accelerated change of frequency. The time interval is set to minutes, specifically five to ten minutes, to balance data accuracy and calculation efficiency.

[0079] Specifically, in the monitoring period, the system records acoustic emission frequency data at five-minute intervals. When the frequency values corresponding to 8:30 and 8:35 of adjacent time points are 120 and 150 times respectively, the frequency change rate is calculated to be 6 times per minute. Then the frequency value corresponding to the next time interval 8:40 is 190 times, and the new frequency change rate is calculated to be 8 times per minute. By twice differentiating the two consecutive frequency change rates, the acoustic emission frequency increase rate is obtained to be 0.4 times per square minute. This numerical increase rate index can be directly compared with the preset threshold, providing accurate quantitative basis for judging whether the deformation body enters the precursor stage of rupture.

[0080] As a preferred embodiment, the scheme of the present application is implemented as follows: In the process of monitoring the dumping deformation body, the calculation method of the acoustic emission frequency increase rate includes the following steps: First, the acoustic emission frequencies N5, N6 corresponding to the continuous time points t5, t6 are obtained. For example, in a certain dumping deformation body monitoring, t5 is 10:00, and the corresponding acoustic emission frequency N5 is 100 times / minute; t6 is 10:30, and the corresponding acoustic emission frequency N6 is 150 times / minute.

[0081] Secondly, the frequency change rate is calculated. The specific calculation formula is =(N6-N5) / (t6-t5). Substituting the above data, we get =(150-100) / (30 minutes)=1.67 times / minute 2 .

[0082] Further, the frequency change rates corresponding to the continuous time points t7, t8 are obtained. For example, t7 is 11:00, and the corresponding frequency change rate is 1.67 times / minute 2 ; t8 is 11:30, and the corresponding frequency change rate is 2.33 times / minute 2 .

[0083] Finally, the acoustic emission frequency increase rate The calculation formula is ( - ) / (t8-t7). Substituting the above data, we get =(2.33-1.67) / (30 minutes)=0.022 times / minute 3 .

[0084] In some of the above schemes of the present application, a method for stability determination by deformation velocity, acoustic emission frequency and duration is proposed. However, in the process of critical state recognition, the existing method fails to establish a dynamic correlation between the acoustic emission frequency increment and the deformation velocity, resulting in the inability to timely trigger a multi-stage response mechanism and the risk of early warning lag.

[0085] The present application further proposes a critical state determination method, comprising the following steps: calculating the acoustic emission frequency increment per unit time; determining that the critical state is entered when a specific proportional relationship between the increment and the deformation velocity is met; starting a three-stage response mechanism including data sampling enhancement, unmanned aerial vehicle scanning and audible light alarm.

[0086] Among them, the setting of unit time Δ needs to match the real-time processing capability of the monitoring system, and usually takes 5-10 minutes as the data window. The value of material critical coefficient α is obtained by laboratory calibration, which is 1.8 for granite materials and 1.6 for shale materials. In the three-stage response mechanism, the unmanned aerial vehicle group carries a three-dimensional laser scanner for millimeter-level displacement monitoring, and the dynamic memory allocation technology is used to ensure the stability of the system.

[0087] Specifically, the monitoring system calculates the increment of acoustic emission events per minute in real time, and when the increment reaches the product of the deformation velocity and the material coefficient, it indicates that the microcrack enters the acceleration stage. At this time, the system automatically enhances the data acquisition density to once per minute to ensure the capture of transient signal characteristics. The simultaneously started unmanned aerial vehicle group performs high-density displacement scanning along the preset route to generate a three-dimensional deformation field cloud map. When the third stage response is triggered, the alarm system uses a multi-frequency acoustic wave combined emission mode to penetrate complex terrain environment, and the optimal escape path is automatically generated and pushed to the terminal device after the evacuation plan is started. This determination mechanism establishes a quantitative relationship between the frequency mutation and the deformation velocity, realizes the multi-dimensional monitoring connection from microcrack to macro displacement, and shortens the early warning response time to within 30% of the traditional method.

[0088] As a preferred embodiment, the scheme of the application is implemented as follows: in the process of monitoring the dumping deformation body, when the monitoring system detects the frequency increment ΔN of acoustic emission in unit time Δt, the increment is obtained by calculating the difference of acoustic emission sensor data of two consecutive monitoring periods. The deformation velocity v is obtained in real time by the displacement change rate collected by the displacement sensor, and the material critical coefficient α is preset to 1.8 according to the rock type. When ΔN / Δt≥1.8×v is met, the system automatically determines that the critical state is entered. At this time, the three-level response mechanism is triggered in turn: the sampling frequency of the data acquisition module is adjusted from once every 5 minutes to once every minute; the UAV group carries out high-precision displacement modeling of the surface of the deformation body by using a three-dimensional laser scanner; and the audible and light alarm device is started synchronously, and the emergency management platform automatically generates an evacuation path and pushes it to the terminal of the relevant personnel.

[0089] In some of the above schemes of the application, the critical state determination process lacks a dynamic response mechanism, resulting in a lag in triggering the early warning signal and failing to start multi-level prevention and control measures in time before the disaster occurs.

[0090] The application further proposes a calculation method of the frequency increment ΔN of acoustic emission in unit time Δt, and determines that the critical state is entered when ΔN / Δt≥α×v, and starts the three-level response.

[0091] Among them, the setting range of unit time Δt is 10-30 minutes, the value of material critical coefficient α is determined through rock mass mechanics experiment, and 1.8 is preferentially used as a typical value. The deformation velocity v is obtained by difference calculation of displacement, and the frequency increment ΔN of acoustic emission is obtained by frequency difference value statistics of adjacent monitoring periods. In the three-level response, the data sampling frequency is improved by adjusting the clock period of the sensor acquisition module, the UAV group scanning uses a preset flight path mode to cover the monitoring area, and the linkage of the audible and light alarm device and the evacuation plan is triggered by the central controller.

[0092] Specifically, when the ratio of the frequency increment ΔN of acoustic emission and the deformation velocity v exceeds α in the monitoring interval T, the system automatically enters the critical state determination process. The first level response improves the sampling frequency to once every minute, which captures high-frequency micro-cracking signals by increasing the data density; the second level response starts the UAV group to perform three-dimensional laser scanning on the surface of the deformation body along the preset path, and generates a displacement field distribution map to verify the internal deformation trend; and the third level response sends a high-frequency warning signal through the audible and light alarm device, and sends an evacuation instruction to the preset emergency terminal. For example, when α is 1.8 and Δt is 15 minutes, if ΔN is 27 and v is 10 mm / h, then ΔN / Δt=1.8 times / min and α×v=1.8×10=18, which meets the condition of 1.8 times / min≥18, at this time, the system executes the three-level response measures in turn. The scheme realizes closed-loop control from data acquisition to emergency response by quantifying the critical state determination threshold and multi-level response logic.

[0093] As a preferred embodiment, the scheme of the application is implemented as follows: acoustic emission sensors are installed in a certain landslide monitoring area to continuously monitor acoustic emission frequency data. Based on the acoustic emission frequency sequence collected for three consecutive hours, the frequency growth model parameters are obtained by nonlinear regression fitting, wherein the initial frequency N o is 28 times / minute, and the growth coefficient k is determined as 0.15 hour -1 . The material rupture threshold β is set to 450 times / minute according to the results of on-site core tests. When the monitoring system records the current acoustic emission frequency =210 times / minute at 14:30, the disaster occurrence time is calculated by substituting the formula =14:30+[ln450-ln210] / 0.15, which obtains =14:30+16.2 hours. It is thus determined that the disaster occurrence time is within the next 24 hours, the system automatically triggers a red warning and links to the emergency platform to start the personnel evacuation plan, and simultaneously pushes the risk avoidance notice to the surrounding area.

[0094] In some of the above schemes of the application, the deformation amount needs to rely on the accurate measurement of the deformable angle, but in actual application, the dynamic change of the deformable angle is difficult to be obtained in real time by conventional measurement means, resulting in the problems of lag and error accumulation in the calculation result of the deformation amount.

[0095] The application further proposes a method for determining the deformable angle: when the point is located on the toppling deformation surface, an inclination sensor is installed at the point; the angle between the tangent plane at the point and the horizontal plane is continuously measured; and the deformable angle is calculated as the initial reference angle minus the absolute difference between the tangent plane and the horizontal plane.

[0096] The inclination sensor is installed at the key stress area of the deformation surface, and the measurement frequency is set to 100-1000 times per second. The angle between the tangent plane and the horizontal plane is measured by using a double-axis inclination sensor, and the measurement accuracy reaches ±1°. The initial reference angle is determined by the average value of the continuous 3-hour monitoring data in the stable state of the deformation body, and the typical value is 5°-10°. The calculation of the deformable angle introduces absolute value operation, which eliminates the sign interference caused by the change of the toppling direction.

[0097] ​Specifically, after installing the inclination sensor at the point, the angle data between the tangent plane and the horizontal plane is collected in real time to establish the time series of angle changes. The initial reference angle is determined by the statistical mean value in the stable state, effectively eliminating the measurement noise. In the calculation formula of the deformable angle, the operation of degree minus the absolute value of the angle difference not only retains the deformation direction information, but also quantifies the degree of angle deviation. For example, when the tangent plane angle changes from the initial degree to degree, the deformable angle is calculated as degree, which directly reflects the deviation degree of the current deformation state from the initial stable state. This method realizes the real-time update of the deformable angle by comparing it with the reference value, avoids the cumulative error caused by traditional static angle measurement, and improves the calculation accuracy of the deformation.

[0098] As a preferred embodiment, the scheme of the application is implemented as follows: a typical monitoring point M is selected on the dumping deformation surface, a MEMS inclination sensor is installed, and the sensor axis is ensured to be parallel to the tangent plane of the rock mass surface during installation. The data acquisition system records the real-time angle γ between the tangent plane and the horizontal plane at a frequency of once per minute, and sends the measurement value to the central processing unit through the wireless transmission module. In the initial stable state, the average value of the γ values collected for ten minutes is taken as the reference angle γ 0 . During the monitoring process, when the real-time angle γ fluctuates, the central processing unit automatically calculates the deformable angle When the value of θ exceeds the preset threshold value, the system automatically triggers the switching mechanism of the deformation calculation formula, for example, when θ changes from the acute angle range to the obtuse angle range, the deformation calculation mode is switched from the sine tangent mode to the cosecant absolute value mode.

[0099] Through the above technical scheme, the application effectively solves the deformation calculation error problem caused by inaccurate measurement of the deformable angle in the prior art. By real-time determination of the angle change of the tangent plane of the rock mass surface through the inclination sensor, the deformable angle is dynamically calculated in combination with the initial reference angle, so that the deformation calculation formula can accurately match the actual deformation state of the rock mass. This method significantly improves the calculation accuracy of the deformation D, provides a reliable data basis for subsequent acoustic emission frequency conversion and pre-failure identification, and avoids the risk of misjudgment caused by angle measurement deviation.

[0100] The above only describes the embodiments of the application and does not limit the protection scope of the application. For those skilled in the art, the application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A method for identifying precursors of a collapse deformation body rupture based on acoustic emission monitoring, characterized by, Comprising the following steps: Step 1: Set up a monitoring area in the pouring deformation body, fix the acoustic emission sensor on one side or the bottom edge of the pouring deformation body, take the time length t1 as the monitoring period, and continuously monitor the acoustic emission intensity; Step 2: Establish the relationship equation between acoustic emission intensity and deformation, take the top point A of the monitoring area as the reference point, measure the horizontal displacement of each point in the monitoring area by using the total station, and calculate the deformation D of each point except point A according to the acoustic emission intensity-deformation relationship equation; Step 3: converting the deformation amount D into the acoustic emission frequency N and the duration , drawing the acoustic emission frequency-time curve and the acoustic emission intensity-time curve; Step 4: Calculate the deformation velocity v and the deformation velocity change rate a; Step 5: Stability determination: When the conditions that the deformation speed v is constant or decreases, the rate of change of the degree of deformation decreases, the acoustic emission frequency increases, the acoustic emission duration increases, and the rate of increase of the acoustic emission frequency is greater than a threshold value are satisfied , the rate of increase of the acoustic emission duration is greater than a threshold value , the crack precursor is determined. When the conditions are met: the deformation velocity v is unchanged or decreases, the deformation degree gradually decreases, the acoustic emission frequency gradually decreases, and the acoustic emission intensity gradually decreases, it is determined that the deformation body is stable; Step 6: Formulate a warning scheme according to the pre-failure signs and implement it.

2. The method of claim 1, wherein, The calculation of deformation D in step two comprises the following steps: Step 2.1: Measure the horizontal distance L between point M and reference point A, point M being any point in the monitoring area; Step 2.2: Measure the included angle β between the line connecting point M and point A and the central axis; Step 2.3: Obtain the deformable angle θ recognizable by the monitoring system; Step 2.4: When θ is in the range of 0 degrees to 90 degrees, calculate the deformation D=L×sinβ×tanθ; wherein L is the horizontal distance between point M and reference point A, β is the included angle between the line connecting point M and point A and the central axis, and θ is the deformable angle recognizable by the monitoring system; Step 2.5: When θ is in the range of 90 degrees to 180 degrees, calculate the deformation D=L×sinβ×|cotθ|; wherein L is the horizontal distance between point M and reference point A, β is the included angle between the line connecting point M and point A and the central axis, and θ is the deformable angle recognizable by the monitoring system; Step 2.6: Determine the position of point M' after deformation according to D and θ.

3. The method of claim 1, wherein, The relationship equation between acoustic emission intensity and deformation in step two is: S=K×[(1-2υ) / (1-υ)] Wherein: S is the acoustic emission intensity; K is the quality density of rock material; υ is the Poisson's ratio of rock material.

4. The method of claim 1, wherein, The calculation of deformation velocity v and deformation velocity change rate a in step four comprises the following steps: Step 4.1: Obtain the displacement amounts d1, d2 corresponding to the continuous time points t1, t2; Step 4.2: Calculate the deformation velocity v=(d2-d1) / (t2-t1); wherein t1, t2 are continuous time points, and d1, d2 are displacement amounts at corresponding time points; Step 4.3: Obtain the deformation velocities v3, v4 corresponding to the continuous time points t3, t4; Step 4.4: Calculate the deformation velocity change rate a=(v4-v3) / (t4-t3); wherein t3, t4 are continuous time points, and v3, v4 are deformation velocities at corresponding time points.

5. The method of claim 2, wherein, The calculation formula for converting deformation D into acoustic emission frequency N in step three is: N = C x D 2 Wherein C is the material conversion coefficient; D is the deformation.

6. The method of claim 1, wherein, The duration described in step three The calculation method is: Step 6.1 : Define monitoring interval period T = t1 - t a where t a is the time of arrival of the monitoring zone boundary to the slip surface, and t1 is the time of departure from the slip surface. Step 6.2: Sum the duration of all acoustic emission events over the cumulative T period ; Step 6.3: Calculate duration ; where T is the monitoring interval, is the sum of the durations of all acoustic emission events in the T period.

7. The method of claim 1, wherein, The calculation method of acoustic emission frequency increment rate in step five is: Step 7.1: Obtain the acoustic emission frequencies N5, N6 corresponding to the continuous time points t5, t6; Step 7.2: Calculate the frequency change rate = (N6-N5) / (t6-t5); where t5, t6 are consecutive time points, N5, N6 are the acoustic emission frequencies at the corresponding time points; Step 7.3: Obtain the frequency change rate corresponding to the consecutive time points t7, t8 ; Step 7.4: Calculate the rate of increase in acoustic emission frequency ; where t7, t8are consecutive points in time, is the rate of change in frequency at the corresponding points in time.

8. The method of claim 1, wherein, Step five also includes critical state determination: Step 8.1: Calculate the acoustic emission frequency increment ΔN in unit time Δt; Step 8.2: When ΔN / Δt≥α×v is satisfied, it is determined that the critical state is entered; Wherein α is the critical coefficient of the material; v is the deformation velocity; Δt is the unit time; ΔN is the frequency increment of acoustic emission in unit time Δt; The third-level response is started in the critical state: First level: the data sampling frequency is increased to 1 time per minute; Second level: the UAV group is started to perform three-dimensional displacement scanning; Third level: the acousto-optic alarm is triggered and the evacuation plan is started.

9. The method of claim 1, wherein, The early warning scheme in step six includes: Step 9.1: Establishing the Acoustic Emission Frequency Growth Model ; Step 9.2: Calculate time of disaster occurrence ; wherein: is the current time, is the current acoustic emission frequency, β is the material fracture threshold, and k is the frequency growth coefficient; Step 9.3: Graded response: When >72 hours, issue a blue alert; When 24 hours ≤ 72 hours, a yellow pre-warning is issued; When ≤ 24 hours, a red alert is issued and full evacuation is initiated.

10. The method of claim 2, wherein, It also includes a method for determining the deformable angle θ: Step 10.1: When point M is located on the dumping deformation surface, install an inclination sensor at point M; Step 10.2: Continuously measure the angle γ between the tangent plane at point M and the horizontal plane; Step 10.3: Calculate the deformable angle θ=90°-|γ-γ0|; wherein γ is the angle between the tangent plane at point M and the horizontal plane, γ0 is the reference angle in the initial stable state, and θ is the deformable angle.

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