Micro-motion-based dangerous rock mass monitoring and early warning method and related equipment
By obtaining the critical value of rock vibration characteristics through uniaxial compression tests indoors and comparing and analyzing it in the field, the problem of lack of unified criteria in monitoring dangerous rock masses was solved, and the effect of consistent early warning and early identification of crack initiation across scenarios was achieved.
Patent Information
- Application Number
- CN202511728323.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-02-13
AI Technical Summary
Current monitoring of unstable rock masses lacks unified and quantifiable criteria, relies on subjective judgment based on experience, and makes it difficult to identify early signs of crack initiation. Existing methods cannot achieve consistent cross-scenario judgment and effective early warning.
By conducting uniaxial compression tests indoors and using micro-motion probes to collect vibration characteristics of rock samples, the critical values of RMS velocity-amplitude ratio, dominant frequency, and attenuation constant are calculated. Comparative analysis is then conducted in the field to trigger early warning of unstable rock masses and establish a unified quantitative standard.
It has achieved consistent monitoring and early warning of dangerous rock masses across different scenarios, reduced false alarms and missed alarms, improved the reliability of judgments and the consistency of engineering implementation, and provided the ability to identify crack initiation in advance.
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Figure CN121521630A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of mountain disaster early warning, in particular to a dangerous rock mass monitoring and early warning method based on micro-motion and related equipment. BACKGROUND
[0002] The collapse and rockfall disaster caused by the destruction of dangerous rock mass has the characteristics of strong suddenness, great destructive power and wide influence range. Mainly including:
[0003] 1. Direct threat to personal safety
[0004] Collapse and rockfall often have no premonition or very short warning time, and personnel are difficult to avoid. The impact force of high-speed falling rock blocks is huge, which can directly cause the death or serious injury of the hit person.
[0005] Rockfall bounces and rolls on the slope surface, and the influence range often exceeds the direct area at the slope foot, threatening the personnel gathering area of roads, houses, farmland, sheds, etc. below.
[0006] If there is a dangerous rock mass under the mountain scenic area trestle, viewing platform and mountain climbing trail, it will pose a serious threat to tourist safety.
[0007] 2. Damage to transportation infrastructure
[0008] Directly hitting a moving car or train can cause a major accident of car damage and death, and a large amount of collapse can bury the highway or railway instantly, causing complete traffic disruption. Large collapses can destroy bridges and damage tunnel entrances or linings.
[0009] Clearing large and numerous rock blocks often requires heavy machinery and a long time, and the mountainous area has few alternative routes, so the distance of detour is long and the transportation cost is greatly increased. The rockfall-prone section needs to continuously invest in monitoring, installation of protective nets, active cleaning and other maintenance work.
[0010] 3. Damage to buildings and engineering
[0011] Rockfall can penetrate roofs and damage walls, causing partial or complete collapse of houses, and also threatens schools, hospitals, factories, substations, communication base stations, water conservancy facilities (such as power station pressure pipes, workshops), etc.
[0012] Collapse may block the spillway, destroy power station facilities or directly impact the dam body.
[0013] In summary, the natural disaster caused by the destruction of dangerous rock mass has caused great loss to national property and people's life safety, and it is urgent to monitor and warn the dangerous rock mass.
[0014] At present, the early warning of dangerous rock mass is based on the investigation results of topographic and geological reconnaissance, topographic interpretation using topographic maps or aerial photographs, etc. Each investigation project is scored, and the risk degree is determined by the scoring method. However, these methods are largely dependent on the subjective judgment of the judges, and the problem is that different judges may come to different investigation results. In addition, the investigation of rock fissures to identify the damage degree is high in cost and not very practical. And there is no effective monitoring and early warning method for dangerous rock mass. SUMMARY
[0015] The technical problem to be solved by the present application is that the existing dangerous rock mass monitoring lacks unified quantifiable criteria, relies on subjective experience, and is difficult to set and verify the threshold value on site and identify the crack initiation precursor in advance. The purpose is to provide a dangerous rock mass monitoring and early warning method based on microseism and related equipment, which solves the problem of realizing consistent criteria across scenes and early warning by the critical value of vibration characteristics.
[0016] The present application is realized by the following technical scheme:
[0017] A dangerous rock mass monitoring and early warning method based on microseism, comprising:
[0018] In the laboratory, a uniaxial compression test is performed on different types of rock samples by a testing machine, a microseism probe is arranged on the side of the rock sample, and a microseism probe is arranged on the stable part of the pressure plate, and the microseism signals of the rock sample from the initial loading to the failure process are collected in the uniaxial compression test;
[0019] Based on the microseism signals, the vibration characteristics of the rock sample are obtained, including the RMS velocity amplitude ratio, the dominant frequency and the attenuation constant, wherein: the microseism signals are processed in the frequency domain and the time-frequency domain, the dominant frequency is obtained by Fourier transform, and the RMS velocity values of the upper and lower microseism probes are obtained by wavelet analysis;
[0020] The RMS velocity amplitude ratio is calculated according to the RMS velocity values of the upper and lower microseism probes, the segmented analysis is performed according to the uniaxial compression stress stage, the characteristic moments corresponding to the crack initiation, crack propagation and penetration are identified, the RMS velocity amplitude ratio corresponding to the crack initiation is taken as the RMS velocity amplitude ratio critical value of this type of rock, and the dominant frequency and the attenuation constant at the failure moment are recorded as the critical values of the dominant frequency and the attenuation constant;
[0021] In the field, the upper microseism probe is arranged on the surface of the dangerous rock mass to be tested, and the lower microseism probe is arranged on the adjacent stable bedrock, and the microseism signals are continuously collected according to the same sampling parameters as the indoor test;
[0022] The RMS velocity amplitude ratio, predominant frequency and attenuation constant obtained by field collection are calculated and compared with corresponding indoor critical values, and the instability of the dangerous rock mass is verified and determined according to the comparison and analysis.
[0023] Further, when any one of the RMS velocity amplitude ratio, predominant frequency or attenuation constant calculated in the field reaches or exceeds the corresponding indoor critical value, the instability warning of the dangerous rock mass is triggered, and the validity of the critical value is verified through subsequent monitoring results.
[0024] Further, when determining the RMS velocity amplitude ratio critical value, the time sequence of the RMS velocity amplitude ratio is spatiotemporally associated with the macroscopic damage phenomena in the rock compression and damage process, including the crack appearance time and the main crack breakthrough node.
[0025] Further, the RMS velocity amplitude ratio R is calculated according to the following formula:
[0026]
[0027] wherein, and are the velocity values of the lower microseismic probe and the upper microseismic probe at the i-th sampling point, is the sampling number.
[0028] Further, the values of the RMS velocity amplitude ratio at the crack initiation time obtained from multiple groups of samples of the same rock are statistically analyzed to form the RMS velocity amplitude ratio critical value or critical value interval of the rock.
[0029] Further, the collection of the field microseismic signals covers the continuous process from the stable period, the instability critical period, the damage instant to the decay period after the damage.
[0030] Further, when any one of the RMS velocity amplitude ratio, predominant frequency or attenuation constant calculated in the field reaches or exceeds the corresponding indoor critical value, the instability warning of the dangerous rock mass is triggered, and the validity of the critical value is verified through subsequent monitoring results.
[0031] The application also provides a microseismic-based dangerous rock mass monitoring and warning system for the microseismic-based dangerous rock mass monitoring and warning method as described above, comprising:
[0032] The microseismic probe is arranged on the rock sample / dangerous rock mass and the pressure plate / stable bedrock in the indoor test and field monitoring respectively to collect the microseismic signals.
[0033] The data acquisition unit is used for synchronously collecting and recording the microseismic signals according to the set sampling parameters.
[0034] A signal processing unit is configured to perform Fourier transform and wavelet analysis on the microseismic signals collected, and calculate RMS velocity amplitude ratio, dominant frequency and attenuation constant;
[0035] A pre-warning determination unit is configured to compare the RMS velocity amplitude ratio, the dominant frequency and the attenuation constant obtained in the field with the corresponding critical values determined in the laboratory, and output the determination and verification results of the unstable dangerous rock mass.
[0036] The application further provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the microseismic-based dangerous rock mass monitoring and pre-warning method as described above when executing the program.
[0037] The application further provides a computer readable storage medium, which stores a computer program, and the program is executable on a processor to implement the microseismic-based dangerous rock mass monitoring and pre-warning method as described above.
[0038] Compared with the prior art, the application has the following advantages and beneficial effects: the critical values of RMS velocity amplitude ratio, dominant frequency and attenuation constant of different rock types are obtained through laboratory uniaxial compression tests, and the unified quantitative standard is achieved, and the empirical judgment is avoided. The critical value is determined according to the RMS velocity amplitude ratio corresponding to the crack initiation stage, and the instability precursor can be identified in advance compared with the scheme relying on the post-failure signs. The consistent probe arrangement and signal processing procedures (frequency domain / time-frequency domain+RMS calculation) are used in the laboratory and the field, and the critical values can be directly migrated for field determination, and the engineering implementation consistency is good.
[0039] The RMS velocity amplitude ratio is used as the main criterion, and the values of the dominant frequency and the attenuation constant at the failure time are compared and checked to reduce false positives / missed reports. The ratio criterion formed by the upper and lower probes weakens the influence of the strength of overall environmental vibration, coupling differences and equipment gain changes to a certain extent, and the determination is more robust. The critical values or intervals are obtained by statistical analysis of a plurality of rock samples, and the adaptability of the method to different geological bodies is enhanced. The field monitoring results are compared and verified with the laboratory critical values to form a closed loop of "experiment-application-verification", and the conclusion reliability is improved. The complete process from probe arrangement-signal processing-stage segmentation-critical value acquisition-site determination is given, which is convenient for large-scale deployment and standardized operation and maintenance. BRIEF DESCRIPTION OF DRAWINGS
[0040] In order to more clearly illustrate the technical solutions of the example embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:
[0041] Figure 1 A test simulation schematic diagram of a dangerous rock mass monitoring and early warning method based on microseism of the present application;
[0042] Figure 2 A schematic diagram of the relationship between RMS velocity amplitude ratio and predominant frequency of a dangerous rock mass monitoring and early warning method based on microseism of the present application;
[0043] Figure 3 A schematic diagram of the relationship between RMS velocity amplitude ratio and attenuation coefficient of a dangerous rock mass monitoring and early warning method based on microseism of the present application;
[0044] Figure 4 A predominant frequency graph when a dangerous rock mass is destroyed based on microseism of the present application;
[0045] Figure 5 A velocity-time graph of a dangerous rock mass monitoring and early warning method based on microseism of the present application;
[0046] Figure 6 A RMS velocity amplitude ratio-time graph of a dangerous rock mass monitoring and early warning method based on microseism of the present application;
[0047] Figure 7 An attenuation acceleration-time graph when a dangerous rock mass is self-vibrating based on microseism of the present application;
[0048] Figure 8 A field upper microseism probe velocity-time graph of a dangerous rock mass monitoring and early warning method based on microseism of the present application;
[0049] Figure 9 A field lower microseism probe velocity-time graph of a dangerous rock mass monitoring and early warning method based on microseism of the present application. DETAILED DESCRIPTION
[0050] In order to make the purpose, technical scheme and advantages of the present application more clear and apparent, the present application is further described in detail below in combination with embodiments and drawings, and the schematic embodiments of the present application and the description thereof are only used to explain the present application, and do not limit the present application.
[0051] Embodiment 1
[0052] A dangerous rock mass monitoring and early warning method based on microseism, as shown in Figures 1-9 , comprises:
[0053] In a laboratory, a uniaxial compression test is performed on different types of rock samples by a testing machine, an upper microseism probe is arranged on the side of the rock sample, and a lower microseism probe is arranged at a stable part of a pressure bearing plate, and microseism signals of the rock sample from the initial loading to the whole process of destruction are collected in the uniaxial compression test;
[0054] Based on the micro-motion signal, the vibration characteristics of the rock sample are obtained, and the vibration characteristics include an RMS velocity amplitude ratio, a predominant frequency and an attenuation constant, wherein: the micro-motion signal is processed in a frequency domain and a time-frequency domain, the predominant frequency is obtained through Fourier transform, and the RMS velocity values of the upper micro-motion probe and the lower micro-motion probe are calculated through wavelet analysis;
[0055] The RMS velocity amplitude ratio is calculated according to the RMS velocity values of the upper micro-motion probe and the lower micro-motion probe, the segmented analysis is carried out according to the uniaxial compression stress stage, the characteristic moments corresponding to crack initiation, crack propagation and breakthrough are identified, the RMS velocity amplitude ratio corresponding to crack initiation is taken as the RMS velocity amplitude ratio critical value of the rock, and the predominant frequency and the attenuation constant at the moment of failure are recorded as the critical values of the predominant frequency and the attenuation constant;
[0056] The upper micro-motion probe is arranged on the surface of the dangerous rock body to be tested in the field, the lower micro-motion probe is arranged on the adjacent stable bedrock, and the micro-motion signals are continuously collected according to the sampling parameters consistent with the indoor test;
[0057] The RMS velocity amplitude ratio, the predominant frequency and the attenuation constant obtained in the field are calculated and compared with the corresponding indoor critical values, and the instability of the dangerous rock body is verified and determined according to the comparison and analysis.
[0058] The present application is directed to the construction and engineering application of quantitative criteria for instability warning of dangerous rock bodies, aiming at the pain points in the prior art that the discrimination standards are not unified, rely on experience and are difficult to identify precursors in advance, and proposes an integrated technical route of "indoor critical value establishment - field consistent application - closed-loop verification". The method is: in the laboratory, uniaxial compression test is carried out on different rock samples, the upper and lower micro-motion probes are arranged on the sample side and the pressure plate respectively, and the micro-motion signals from the initial loading to the failure are collected; after frequency domain and time-frequency domain processing, the RMS velocity amplitude ratio, the predominant frequency and the attenuation constant are calculated, and the RMS velocity amplitude ratio is segmented according to the stress stage, the evolution of the RMS velocity amplitude ratio with "crack initiation - propagation - breakthrough - failure" is corresponded in time and space with the macroscopic failure event, the RMS velocity amplitude ratio critical value of the rock is determined according to the value corresponding to crack initiation, and the critical values of the predominant frequency and the attenuation constant at the moment of failure are recorded. Then, in the field, the same type of probes are arranged on the dangerous rock body and the adjacent stable bedrock, the three vibration characteristics are calculated according to the consistent process in the laboratory, compared with the indoor critical values, the instability warning is realized, and the post-event verification is completed.
[0059] The present application extracts the critical value of the "damage initiation stage" from the laboratory full-process data in the mode of "double-probe ratio measurement + stress stage segmented analysis + space-time alignment with macroscopic damage", and can be transferred to the field for judgment; taking RMS velocity amplitude ratio as the main criterion, and remarkable frequency and attenuation constant as auxiliary criteria (verification), a reproducible and generalizable quantitative standard is formed. Thus, early warning, reducing false positives / misses, and enhancing anti-interference and engineering applicability are achieved. The supporting system is composed of microseismic probes, data acquisition, signal processing and early warning judgment units, which can be implemented corresponding to the method claim, supporting standardized deployment and operation in different lithology and different scenarios.
[0060] As shown in Figures 2-3 , the three vibration characteristics of remarkable frequency, RMS velocity amplitude ratio and attenuation constant can be used as effective indicators to evaluate the rockfall risk of dangerous rock mass. The remarkable frequency and attenuation constant remain unchanged, and the microseismic data of dangerous rock and bedrock are measured respectively. The RMS velocity amplitude ratio of the two data is calculated. When the RMS velocity amplitude ratio increases, the risk of dangerous rock mass increases.
[0061] Based on the above theory, uniaxial compression tests of different kinds of rocks are carried out to obtain the critical values of remarkable frequency, RMS velocity amplitude ratio and attenuation constant when the rock is damaged, so as to give the critical threshold of dangerous rock mass damage. As shown in Figure 1 , it includes:
[0062] A microseismic probe is placed on the dangerous rock mass (rock) sample, which is recorded as the upper probe; a microseismic probe is placed on the pressure plate, which is recorded as the lower probe.
[0063] The microseismic data during the entire process of rock sample compression to failure is recorded.
[0064] The dynamic signal of rock compression and failure is mainly transformed from time domain to frequency domain through Fourier series and Fourier transform. The seemingly irregular time domain signal can be regarded as a periodic function from negative infinity to positive infinity, so the time domain signal can be transformed into a frequency domain signal through Fourier transform . Thus, the remarkable frequency of rock compression and failure is obtained.
[0065] The data is processed by wavelet analysis method to obtain the RMS velocity values of the upper and lower microseismic probes. The RMS velocity amplitude ratio is obtained by comparing the RMS velocity value of the upper probe with that of the lower probe.
[0066] The RMS velocity amplitude ratio threshold of rock failure is obtained by analyzing the rock failure process and the change of RMS velocity amplitude ratio.
[0067] The attenuation constant detected by the upper probe during the rock failure process is analyzed as the critical threshold of the attenuation constant of dangerous rock mass failure.
[0068] The critical value obtained by the experiment is applied to the field dangerous rock mass monitoring, and the experimental results are verified, including:
[0069] A microseismic probe is placed on the dangerous rock mass, which is recorded as microseismic up, and another probe is placed on the bedrock, which is recorded as microseismic down. The microseismic up and down data before and after the destruction of the dangerous rock mass are recorded, and the data are processed to obtain the RMS velocity amplitude ratio, which is compared with the experimental data to further verify the accuracy of the experimental results.
[0070] The monitoring and early warning of the dangerous rock mass are quantitatively monitored, and the critical threshold of the predominant frequency, the RMS velocity amplitude ratio and the attenuation constant is given for the dangerous rock mass monitoring. The long-term vibration monitoring of the dangerous rock mass can greatly advance the early warning and prediction time, and give enough time and space for disaster prevention preparation.
[0071] In this embodiment, the uniaxial compression experiment is as follows:
[0072] Prepare the rock sample. The rock sample is cylindrical, and the rock types are coarse sandstone and granite, each with five groups. The sample size is 50*100mm (diameter*height).
[0073] Instrument debugging and installation. The press machine needs to be preheated (usually 10-15 minutes), check whether the oil circuit and control system are normal, calibrate the force sensor and displacement sensor (calibrate regularly according to the equipment instruction manual, and confirm the zero point before the experiment). The loading rate of the press machine is set to 0.1mm / min.
[0074] Place the sample in the center of the lower pressure plate of the testing machine, and adjust the sample axis to coincide with the loading axis of the testing machine (reduce the eccentric loading error) through the alignment device.
[0075] A high-sensitivity microseismic probe (recorded as the upper probe) is tightly attached to the middle area of the side surface of the rock sample, ensuring that the probe and the sample surface have no gap contact to ensure effective transmission of the vibration signal; at the same time, another microseismic probe of the same type (recorded as the lower probe) is fixed on the top surface center of the lower pressure plate of the testing machine, so that it is stably adsorbed on the surface of the metal pressure plate. As shown in Figure 3 ;
[0076] Record the microseismic data of the rock under pressure from the initial loading stage to the elastic deformation stage to the plastic development stage until the slope failure and instability.
[0077] The acquisition method of the predominant frequency is as shown in Figure 4 ,
[0078] Any periodic function can be expanded into an infinite series of linear combinations of orthogonal functions if it satisfies Dirichlet's condition. The seemingly irregular time-domain signal can be regarded as a periodic function from negative infinity to positive infinity, so the time-domain signal can be transformed into a frequency-domain signal by Fourier transform (FT).
[0079] The Fourier series of f(t) in trigonometric form can be expanded as:
[0080]
[0081] The Fourier coefficients an and bn are calculated as follows:
[0082]
[0083] wherein,
[0084] The Fourier series of f(t) in exponential form can be expanded as:
[0085]
[0086] wherein, the Fourier coefficients are
[0087] After the micro-motion data acquisition of the rock uniaxial compression test is completed, the velocity-time graph can be obtained by wavelet analysis, as shown in Figure 5 The velocity-time data obtained is derived, and the upper and lower micro-motion RMS velocity values are calculated by the following formula. The expression is:
[0088]
[0089] In the formula, R is the RMS velocity amplitude ratio, X is the time sequence of the amplitude vibration record of the lower probe, Y is the time sequence of the amplitude vibration record of the upper probe, and n is the sample number. The calculation step length of the present application is 8s.
[0090] The RMS velocity amplitude ratio is obtained by comparing the RMS velocity value of the upper probe with that of the lower probe. Taking granite as an example, as shown in Figure 6 It can be seen that when the RMS velocity amplitude ratio is greater than 10, the ratio value rapidly transitions with the rock damage.
[0091] Combined with the stage characteristics of the rock damage process, such as the weak vibration of initial loading, the stable signal of the elastic stage, the crack impact vibration of the plastic stage, and the violent vibration at the moment of damage, the RMS velocity amplitude ratio change trend of different stress stages is dynamically tracked and compared. After data processing of each kind of rock, the critical values of multiple samples form a critical value interval.
[0092] The attenuation constant of the rock during the rock failure is obtained by using the microseismic data of the upper probe during the rock compression failure, as shown in the following formula: Figure 7
[0093] In this embodiment, when any one of the RMS velocity amplitude ratio, the predominant frequency or the attenuation constant calculated in the field reaches or exceeds the corresponding indoor critical value, a dangerous rock instability early warning is triggered, and the effectiveness of the critical value is verified through subsequent monitoring results.
[0094] In this embodiment, when determining the RMS velocity amplitude ratio critical value, the time sequence of the RMS velocity amplitude ratio is spatiotemporally associated with the macroscopic failure phenomena in the rock compression failure process, including the crack appearance time and the main crack breakthrough node.
[0095] In this embodiment, the RMS velocity amplitude ratio R is calculated according to the following formula:
[0096]
[0097] wherein, and are the velocity values of the lower microseismic probe and the upper microseismic probe at the i th sampling point, respectively, is the sampling number.
[0098] Furthermore, the values of the RMS velocity amplitude ratio at the crack initiation time obtained from multiple groups of the same rock sample are statistically analyzed to form the RMS velocity amplitude ratio critical value or critical value interval of the rock.
[0099] Furthermore, the collection of the field microseismic signals covers the continuous process from the stable period, the instability critical period, the failure instant to the decay period after the failure.
[0100] The critical value obtained by the test is applied to the field dangerous rock monitoring, and the test results are verified, as shown in the following figures: Figure 8 and Figure 9 Specifically,
[0101] First, a typical dangerous rock is selected in the field as a monitoring object, and a high-precision microseismic probe is stably installed at a key monitoring point on the surface of the dangerous rock (referred to as microseismic upper), which is used to capture the vibration signals of the dangerous rock in real time; at the same time, another microseismic probe of the same type (referred to as microseismic lower) is arranged on the stable bedrock area (complete bedrock with clear geological boundary from the dangerous rock) below or around the dangerous rock to collect the background vibration signals of the bedrock as a comparison reference.
[0102] The monitoring process needs to cover the complete cycle of the dangerous rock mass from the stable state to the unstable destruction: before the destruction occurs, the vibration data of the dangerous rock mass in the relative stable stage are continuously recorded in the "micro-motion up" and "micro-motion down", the basic vibration characteristics under the daily environmental vibration (such as traffic vibration, natural vibration, etc.) are captured; when the dangerous rock mass enters the unstable critical state due to internal crack expansion, stress concentration and other factors, the abnormal changes of the vibration signal are focused on recording; in the destruction process, the dynamic vibration response of the dangerous rock mass in the falling and collapsing moment is synchronously collected; after the destruction occurs, the vibration attenuation process of the residual rock mass and the bedrock still needs to be monitored for a short time, so as to ensure that the vibration data sequence before and after the destruction is completely obtained.
[0103] In the data processing stage, the values of the predominant frequency, the RMS velocity amplitude ratio and the attenuation constant of the dangerous rock mass (rock) at the time of destruction are calculated according to the calculation method established in the test.
[0104] The predominant frequency, the RMS velocity amplitude ratio and the attenuation constant obtained by the field monitoring are compared and analyzed with the critical threshold value established in the test, and the test results are verified.
[0105] At present, the early warning of the dangerous rock mass is based on the investigation results of topographic and geological reconnaissance, terrain interpretation using topographic maps or aerial photographs, etc. Each investigation project is scored, and the risk degree is determined by the scoring method. However, these methods are largely dependent on the subjective judgment of the judges, and the problem is that different judges may obtain different investigation results. In addition, the investigation of rock cracks to identify the damage degree is high in cost and not very practical.
[0106] The present application obtains the critical values of the predominant frequency, the RMS velocity amplitude ratio and the attenuation constant at the time of rock destruction through indoor uniaxial compression experiments of different kinds of rocks, and uses the values obtained by the test to determine the danger. The present application realizes quantitative monitoring of the monitoring and early warning of the dangerous rock mass, and the monitoring equipment is more light and affordable. The long-term vibration monitoring of the dangerous rock can greatly advance the prediction time of the early warning, leaving enough time and space for disaster prevention preparation.
[0107] Example 2
[0108] A dangerous rock mass monitoring and early warning system based on micro-motion, for realizing the dangerous rock mass monitoring and early warning method based on micro-motion in example 1, comprising:
[0109] A micro-motion probe, for being arranged on the rock sample / dangerous rock mass and the pressure plate / stable bedrock respectively in the indoor test and the field monitoring to collect the micro-motion signal;
[0110] A data acquisition unit, for synchronously collecting and recording the micro-motion signal according to the set sampling parameters;
[0111] A signal processing unit is configured to perform Fourier transform and wavelet analysis on the collected microseismic signals, and calculate RMS velocity amplitude ratio, dominant frequency and attenuation constant.
[0112] A pre-warning determination unit is configured to compare and analyze the RMS velocity amplitude ratio, dominant frequency and attenuation constant obtained in the field with the corresponding critical values determined in the laboratory, and output the determination and verification results of the unstable dangerous rock mass.
[0113] The present application obtains the critical values of RMS velocity amplitude ratio, dominant frequency and attenuation constant of different rock types through laboratory uniaxial compression tests, breaks away from empirical judgment, and realizes unified quantitative standard. The critical value is determined by the RMS velocity amplitude ratio corresponding to the crack initiation stage, which can identify the instability precursor in advance compared with the scheme relying on post-failure signs. The consistent probe layout and signal processing flow (frequency domain / time-frequency domain+RMS calculation) are used in the laboratory and the field, and the critical values can be directly transferred for field determination, and the engineering implementation consistency is good.
[0114] The RMS velocity amplitude ratio is used as the main criterion, and the values of the dominant frequency and attenuation constant at the failure time are compared and checked to reduce false positives / missed reports. The ratio criterion composed of upper and lower probes weakens the influence of the strength of overall environmental vibration, coupling differences and equipment gain changes to some extent, and the determination is more robust. The critical values or intervals are obtained by statistical analysis of various rock samples, which enhances the adaptability of the method to different geological bodies. The field monitoring results are compared and verified with the laboratory critical values to form a closed loop of "experiment-application-verification", which improves the reliability of the conclusions. The complete process from probe layout-signal processing-stage segmentation-critical value acquisition-site determination is given, which is convenient for large-scale deployment and standardized operation and maintenance.
[0115] Embodiment 3
[0116] An electronic device includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the program to realize the microseismic-based dangerous rock mass monitoring and early warning method as described above.
[0117] Embodiment 4
[0118] A computer readable storage medium has a computer program stored thereon, and the program is executed by a processor to realize the microseismic-based dangerous rock mass monitoring and early warning method as described above.
[0119] Those skilled in the art will appreciate that embodiments of the application can be readily used as software, hardware, and / or firmware. In software, implementation can be provided on a computer readable storage medium having stored thereon instructions that, when executed by a computer, can cause the computer to perform a method. The instructions for the embodiments of the application thus provide a program tooi.
[0120] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a computing device such as a computing device 600 in FIG. 6 that perform specific tasks when executed on a processing device or devices (e.g., CPUs or computer processors). Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a computing device such as a computing device 600 in FIG. 6 that perform specific tasks when executed on a processing device or devices (e.g., CPUs or computer processors).
[0121] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flowchart block(s) or block(s). Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a computing device such as a computing device 600 in FIG. 6 that perform specific tasks when executed on a processing device or devices (e.g., CPUs or computer processors). Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a computing device such as a computing device 600 in FIG. 6 that perform specific tasks when executed on a processing device or devices (e.g., CPUs or computer processors).
[0122] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a computing device such as a computing device 600 in FIG. 6 that perform specific tasks when executed on a processing device or devices (e.g., CPUs or computer processors). Figure 1 Figure 1 one or more flowcharts and / or blocks can represent code, circuits, hardware components, or executable computer program instructions on a computing device such as a computing device 600 in FIG. 6 that perform specific tasks when executed on a processing device or devices (e.g., CPUs or computer processors).
[0123] The above detailed description has shown, described, and pointed out the aspects of the application in sufficient detail, that others skilled in the art can follow the present application with assistance of this disclosure. It is currently expected that many modifications, permutations, and additions of this specific implementation of the application will become apparent to those of reasonable skill in the art having benefit of the concept disclosed herein. It is intended that all such modifications, permutations, and additions fall within the scope of the claims.
Claims
1. A micro-motion-based monitoring and early warning method for dangerous rock mass, characterized in that, The method comprises the following steps: Uniaxial compression tests are carried out on different types of rock samples in a laboratory by using a testing machine, an upper micro-motion probe is arranged on the side of the rock sample, a lower micro-motion probe is arranged on the stable part of the pressure plate, and micro-motion signals of the rock sample from the initial loading to the failure are collected in the uniaxial compression test; Vibration characteristics of the rock sample are obtained based on the micro-motion signals, and the vibration characteristics include an RMS velocity amplitude ratio, a predominant frequency and an attenuation constant, wherein: the micro-motion signals are processed in a frequency domain and a time-frequency domain, the predominant frequency is obtained by Fourier transform, and the RMS velocity values of the upper micro-motion probe and the lower micro-motion probe are obtained by wavelet analysis; The RMS velocity amplitude ratio is calculated according to the RMS velocity values of the upper micro-motion probe and the lower micro-motion probe, the uniaxial compression stress stage is analyzed in sections, the characteristic moments corresponding to crack initiation, crack propagation and crack penetration are identified, the RMS velocity amplitude ratio corresponding to the crack initiation is taken as the critical value of the RMS velocity amplitude ratio of the rock, and the predominant frequency and the attenuation constant at the moment of failure are recorded as the critical values of the predominant frequency and the attenuation constant; In the field, an upper micro-motion probe is arranged on the surface of the dangerous rock mass to be tested, a lower micro-motion probe is arranged on the adjacent stable bedrock, and micro-motion signals are continuously collected according to the same sampling parameters as the laboratory test. The RMS velocity amplitude ratio, the predominant frequency and the attenuation constant obtained by collecting the micro-motion signals in the field are calculated and compared with the corresponding laboratory critical values, and the instability of the dangerous rock mass is verified and determined according to the comparison and analysis.
2. The monitoring and early warning method of perilous rock mass based on micro-motion according to claim 1, characterized in that, When any one of the RMS velocity amplitude ratio, the predominant frequency or the attenuation constant calculated in the field reaches or exceeds the corresponding laboratory critical value, a dangerous rock mass instability warning is triggered, and the effectiveness of the critical value is verified through subsequent monitoring results.
3. The micro-motion-based monitoring and early warning method for dangerous rock mass according to claim 1, characterized in that, When determining the critical value of the RMS velocity amplitude ratio, the time sequence of the RMS velocity amplitude ratio is spatiotemporally associated with the macroscopic failure phenomena in the rock compression and failure process, including the crack appearance time and the main crack penetration node.
4. The monitoring and early warning method of the dangerous rock mass based on micro-motion according to claim 1, characterized in that, The RMS velocity amplitude ratio R is calculated according to the following formula: ； in, and The lower and upper micro-motion probes are respectively at the 1st... The velocity value at each sampling point The number of samples.
5. The micro-motion-based monitoring and early warning method for dangerous rock mass according to claim 1, characterized in that, The RMS velocity amplitude ratios of multiple groups of rock samples of the same lithology at the crack initiation moment are respectively counted to form the RMS velocity amplitude ratio critical value or critical value interval of the rock.
6. The monitoring and early warning method of the dangerous rock mass based on micro-motion according to claim 1, characterized in that, The collection of micro-motion signals in the field covers the continuous process from the stable period, the instability critical period, the failure moment to the decay period after the failure.
7. The micro-motion-based monitoring and early warning method for dangerous rock mass according to claim 1, characterized in that, When any one of the RMS velocity amplitude ratio, the predominant frequency or the attenuation constant calculated in the field reaches or exceeds the corresponding laboratory critical value, a dangerous rock mass instability warning is triggered, and the effectiveness of the critical value is verified through subsequent monitoring results.
8. A monitoring and early warning system for dangerous rock mass based on micro-motion, characterized in that, The method comprises the following steps: A micro-motion probe is arranged on the rock sample / dangerous rock mass and the pressure plate / stable bedrock in the laboratory test and field monitoring to collect micro-motion signals; A data acquisition unit is used to synchronously collect and record the micro-motion signals according to the set sampling parameters; A signal processing unit is used to perform Fourier transform and wavelet analysis on the collected micro-motion signals, and calculate the RMS velocity amplitude ratio, the predominant frequency and the attenuation constant. The early warning judging unit is used for comparing and analyzing the RMS speed amplitude ratio, the predominant frequency and the attenuation constant calculated in the field with the corresponding critical values determined in the room, and outputting the judging and verifying results of the dangerous rock mass instability.
9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the micro-motion based dangerous rock mass monitoring and early warning method according to any one of claims 1 to 7 when executing the program.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the micro-motion based dangerous rock mass monitoring and early warning method according to any one of claims 1 to 7.