Method and device for quantifying damage of jointed rock mass based on acoustic emission and DIC data

Abstract

The application discloses a jointed rock mass damage quantification method and equipment based on acoustic emission and DIC data, comprising the following steps: S1, acquiring original acoustic emission, image and stress data; S2, calculating the global strain of the rock mass by using the DIC technology, and acquiring the structure surface strain localization coefficient J i ; S3, drawing an acoustic emission time-main frequency-amplitude graph, and acquiring the time concentration coefficient T i ; S4, drawing acoustic emission event coordinate points, and acquiring the space concentration coefficient S i ; S5, acquiring the acoustic emission activity evaluation index E i according to acoustic emission impact, ringing count and energy data; S6, calculating the damage quantification parameter Q i of the jointed rock mass according to the structure surface strain localization coefficient J i , the time concentration coefficient T i , the space concentration coefficient S i and the acoustic emission activity evaluation index E i ; the application can be used for predicting the damage evolution trend of the jointed rock mass, and solving the problem that the rock damage index of the traditional rock mass damage quantification is not accurate.

Description

Technical Field

[0001] This application relates to the field of rock mass damage prediction technology, and in particular to a method and device for quantifying jointed rock mass damage based on acoustic emission and DIC data. Background Technology

[0002] Accurately describing and quantifying the damage level of surrounding rock in underground rock engineering is of significant practical importance for monitoring and forecasting disasters such as earthquakes, cracking, rockbursts, and collapses during engineering construction and operation. Rock damage mechanics research is divided into macroscopic and microscopic damage aspects. Both involve describing the generation and development of microcracks (microdefects) in the rock matrix material to obtain damage variables, thereby predicting the stress evolution trend of the rock mass and providing early warning of rock mass fracture and failure.

[0003] In practical engineering, rock masses not only consist of rock but also structural planes. The dip angle of these structural planes, along with disturbances such as ground movement and engineering blasting, lead to different failure modes in the rock mass. Both rock material failure and structural plane failure are manifestations of rock mass failure. Damage factors based on rock damage mechanics can only describe the occurrence and propagation of microscopic defects in the rock material, and cannot simultaneously quantify the damage to structural planes. Furthermore, the failure of jointed rock masses involves not only the initiation and propagation of microcracks but also structural plane slippage and wear, resulting in inaccurate quantification of damage to jointed rock masses using traditional methods. Therefore, a reliable method for quantifying the damage of jointed rock masses is urgently needed. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a method and apparatus for quantifying the damage of jointed rock masses based on acoustic emission and DIC data, taking into account both rock blocks and structural surfaces. This method can be used to predict the damage evolution trend of jointed rock masses, solving the problem of inaccurate quantification of rock mass damage using traditional rock damage indices. The technical solution is as follows:

[0005] The first aspect of this application provides a method for quantifying damage in jointed rock masses based on acoustic emission and DIC data, comprising the following steps: S1: acquiring raw acoustic emission, image, and stress data; S2: calculating the global strain of the rock mass using DIC technology and obtaining the strain localization coefficient J of the structural surfaces. i S3: Plot the acoustic emission time-dominant frequency-amplitude diagram to obtain the time lumped coefficient T. i S4: Plot the coordinates of the acoustic emission event points and obtain the spatial lumped coefficient S. i S5: Based on acoustic emission impact, ringing count, and energy data, obtain the acoustic emission activity evaluation index E. i S6: Based on the localization coefficient of strain on the structural surface J i Time concentration factor T i Spatial Concentration Factor S iHarmony Emission Activity Evaluation Index E i The damage quantification parameter Q of the jointed rock mass was calculated. i .

[0006] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, in S2, the structural surface strain localization coefficient J i Including local maximum principal strain and shear strain, and the strain localization coefficient J of the structural surface. i Satisfy the following calculation formula:

[0007]

[0008] in, Let i be the maximum principal strain at the four characteristic points at time i. Let be the maximum shear strain at the four characteristic points at time i.

[0009] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, in step S3, the time concentration factor T i This represents the temporal distribution density of acoustic emission signals with amplitudes ranging from 70 dB to 90 dB, and the time concentration factor T. i Satisfy the following calculation formula:

[0010]

[0011] Where n is the length of the sliding window, A(i+j) represents the amplitude of the acoustic emission signal from 70dB to 90dB, and B(i+j) represents the amplitude of all acoustic emission signals within the window.

[0012] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, in step S4, the spatial concentration factor S i This represents the spatial density distribution of acoustic emission event coordinates within the rock mass, with the spatial concentration factor S. i Satisfy the following calculation formula:

[0013]

[0014] Where m is the number of neighborhoods of the rock sample plane. These represent the number of acoustic emission localization points in the k-th neighborhood of the upper and lower rock blocks, respectively. , respectively, are the average distances between acoustic emission location points in the k-th neighborhood of the upper and lower rock blocks.

[0015] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, in step S5, the acoustic emission activity evaluation index E i Used to quantify the activity and severity of microcracks, and the acoustic emission activity evaluation index E i Satisfy the following calculation formula:

[0016]

[0017] Among them, H i C i F i H represents the number of impacts, ring count, and energy emitted at time i, respectively. p C p F p These represent the number of impacts, ring count, and energy of acoustic emission at peak time, respectively.

[0018] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, in step S6, the damage quantification parameter Q of the jointed rock mass... i The damage quantification of rock blocks and structural planes is comprehensively considered, including local deformation of structural planes, spatiotemporal distribution of microcracks, and the activity and severity of microcracks, and the damage quantification parameter Q of jointed rock masses is also considered. i Satisfy the following calculation formula:

[0019] Q i =J i ·T i ·S i ·E i .

[0020] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, the acquisition of original acoustic emission, image and stress data in S1 specifically includes the following steps: a loading system and an acoustic emission and image acquisition system are run synchronously on a rock mass sample containing a single through joint. One side of the sample is imaged in real time by a camera, and four sensors are arranged on the upper and lower rock blocks on the other side to collect acoustic emission data of the two rock blocks, including waveform data and event location data.

[0021] For example, in the jointed rock mass damage quantification method based on acoustic emission and DIC data provided in one embodiment, in step S2, DIC technology is used to calculate the global strain of the rock mass and obtain the strain localization coefficient J of the structural surface. i Specifically, the steps include: taking four characteristic points on the central axis of the sample, with two characteristic points at the center of the upper and lower rock blocks and two characteristic points at the center of the strain localization zone of the structural surface; and calculating the strain localization coefficient J of the structural surface using the maximum principal strain and shear strain at the four characteristic points.i .

[0022] A second aspect of this application provides an electronic device, including: a memory and a processor, wherein the processor is used to execute a computer management program stored in the memory to implement the above-described method for quantifying jointed rock mass damage based on acoustic emission and DIC data.

[0023] A third aspect of this application provides a computer-readable storage medium having a computer management program stored thereon, which, when executed by a processor, implements the above-described method for quantifying jointed rock mass damage based on acoustic emission and DIC data.

[0024] The beneficial effects of the jointed rock mass damage quantification method and device based on acoustic emission and DIC data provided in some embodiments of this application are as follows: This application employs a jointed rock mass damage quantification method based on acoustic emission and DIC data to quantitatively analyze the damage of jointed rock mass during loading. This method can be used to predict the damage evolution trend of jointed rock mass and the peak stress level under different working conditions, thereby solving the problem of inaccurate quantification of rock mass damage degree by traditional rock damage indicators. Furthermore, the method proposed in this application is easy to implement and can simulate the jointed rock mass damage process through programming software and numerical analysis software. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart illustrating the overall process of the jointed rock mass damage quantification method based on acoustic emission and DIC data in this application.

[0027] Figure 2 A schematic diagram of a rock mass sample loading data, acoustic emission, and image acquisition system;

[0028] Figure 3 A schematic diagram of the characteristic points for calculating the full-field strain and strain localization coefficient after DIC calculation of the rock mass sample;

[0029] Figure 4 The acoustic emission time-dominant frequency-amplitude diagram of the rock mass sample is shown.

[0030] Figure 5 This is a distribution map of the coordinate points of acoustic emission events of the rock mass sample;

[0031] Figure 6The time-domain evolution diagram of the acoustic emission activity evaluation index of rock mass samples;

[0032] Figure 7 A comparison chart of damage quantification parameters and stress evolution data for rock mass samples. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0035] The first aspect of this application provides a method for quantifying damage in jointed rock masses based on acoustic emission and DIC data, such as... Figure 1 As shown, it includes the following steps:

[0036] S1: Acquire raw acoustic emission, image, and stress data;

[0037] Specifically, such as Figure 2 As shown, the rock mass sample of the embodiment contains a single through joint, and a loading system and an acoustic emission and image acquisition system are running synchronously. One side of the sample is captured in real time by a camera, and four sensors are arranged on the upper and lower rock blocks on the other side to collect acoustic emission data of the two rock blocks, including waveform data and event location data.

[0038] S2: The global strain of the rock mass is calculated using DIC technology to obtain the strain localization coefficient J of the structural plane. i ;

[0039] Specifically, such as Figure 3As shown, four characteristic points were selected on the central axis of the sample. Two characteristic points, P1 and P4, were located at the centers of the upper and lower rock blocks, and two characteristic points, P2 and P3, were located at the centers of the strain localization zone on the structural surface. The strain localization coefficient J of the structural surface was calculated using the maximum principal strain and shear strain at the four characteristic points. i The maximum principal strain E1 and maximum shear strain E were obtained using DIC technology. xy The formulas for calculating the two strains are as follows:

[0040]

[0041] Where x and y represent the two coordinate directions of the rock mass plane, and u and v represent the displacements of any point on the plane in the two coordinate directions. and These are the partial derivatives of the planar displacement field in the two coordinate directions, respectively.

[0042] Strain localization coefficient J of structural surface i Including local maximum principal strain and shear strain, and the strain localization coefficient J of the structural surface. i Satisfy the following calculation formula:

[0043]

[0044] in, Let i be the maximum principal strain at the four characteristic points at time i. Let be the maximum shear strain at the four characteristic points at time i.

[0045] S3: Plot the acoustic emission time-dominant frequency-amplitude graph and obtain the time lumped coefficient T. i ;

[0046] Specifically, such as Figure 4 As shown, the time concentration factor T i This represents the temporal distribution density of acoustic emission signals with amplitudes ranging from 70 dB to 90 dB, and the time concentration factor T. i Satisfy the following calculation formula:

[0047]

[0048] Where n is the length of the sliding window, A(i+j) represents the amplitude of the acoustic emission signal from 70dB to 90dB, and B(i+j) represents the amplitude of all acoustic emission signals within the window.

[0049] S4: Plot the coordinates of the acoustic emission event points and obtain the spatial lumped coefficient S. i ;

[0050] Specifically, such as Figure 5As shown, the rock sample plane is divided into several neighborhoods. The spatial concentration factor represents the density distribution of acoustic emission event coordinate points in the rock mass space. The specific calculation formula is as follows:

[0051]

[0052] Where m is the number of neighborhoods of the rock sample plane. These represent the number of acoustic emission localization points in the k-th neighborhood of the upper and lower rock blocks, respectively. , respectively, are the average distances between acoustic emission location points in the k-th neighborhood of the upper and lower rock blocks.

[0053] S5: Obtain the acoustic emission activity evaluation index E based on acoustic emission impact, ringing count, and energy data. i ;

[0054] Specifically, the acoustic emission activity evaluation index E i Used to quantify the activity and severity of microcracks, and the acoustic emission activity evaluation index E i Satisfy the following calculation formula:

[0055]

[0056] Among them, H i C i F i H represents the number of impacts, ring count, and energy emitted at time i, respectively. p C p F p These represent the number of impacts, ring count, and energy of acoustic emission at peak time, respectively.

[0057] S6: Based on the localization coefficient of strain on the structural surface J i Time concentration factor T i Spatial Concentration Factor S i Harmony Emission Activity Evaluation Index E i The damage quantification parameter Q of the jointed rock mass was calculated. i .

[0058] Specifically, the damage quantification parameter Q of jointed rock mass i The damage quantification of rock blocks and structural planes is comprehensively considered, including local deformation of structural planes, spatiotemporal distribution of microcracks, and the activity and severity of microcracks, and the damage quantification parameter Q of jointed rock masses is also considered. i Satisfy the following calculation formula:

[0059] Q i =j i ·T i ·S i ·E i

[0060] Figure 6 The figure shows the time-domain evolution of the acoustic emission activity evaluation index of the rock mass sample. Stress changes reflect rock mass damage to some extent; however, the stress in the rock mass does not exhibit a linear change with loading. Acoustic emission activity evaluation indices based solely on acoustic emission data cannot accurately reflect the stress change trend and damage status of jointed rock masses. This application obtains rock mass damage indices by real-time monitoring of DIC and acoustic emission, such as… Figure 7 As shown, it can match the stress change trend well. This application adopts a jointed rock mass damage quantification method based on acoustic emission and DIC data to quantitatively analyze the jointed rock mass damage during loading. It can be used to predict the damage evolution trend of jointed rock mass. Therefore, the method proposed in this application can effectively solve the problem of inaccurate quantification of rock mass damage degree by traditional rock damage index.

[0061] A second aspect of this application provides an electronic device, including: a memory and a processor, wherein the processor is used to execute a computer management program stored in the memory to implement the above-described method for quantifying jointed rock mass damage based on acoustic emission and DIC data.

[0062] A third aspect of this application provides a computer-readable storage medium having a computer management program stored thereon, which, when executed by a processor, implements the above-described method for quantifying jointed rock mass damage based on acoustic emission and DIC data.

[0063] Although the embodiments of this application have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this application. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this application is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for quantifying damage in jointed rock masses based on acoustic emission and DIC data, characterized in that, Includes the following steps: S1: Acquire raw acoustic emission, image, and stress data; S2: The global strain of the rock mass is calculated using DIC technology to obtain the strain localization coefficient of the structural surfaces. J i ; In S2, the localization coefficient of structural surface strain J i Including local maximum principal strain and shear strain, and the strain localization coefficient of the structural surface. J i Satisfy the following calculation formula: in, For time i The maximum principal strain at the four characteristic points at time t is For time i The maximum shear strain at four characteristic points at time 1; S3: Plot the acoustic emission time-dominant frequency-amplitude graph and obtain the time lumped coefficient. T i ; In S3, the time concentration factor T i This indicates the temporal distribution density of acoustic emission signals with amplitudes ranging from 70dB to 90dB, and the time concentration factor. T i Satisfy the following calculation formula: in, n The length of the sliding window. This indicates the amplitude of the acoustic emission signal in the range of 70dB to 90dB. This indicates the amplitude of all acoustic emission signals within the window; S4: Plot the coordinates of the acoustic emission event points and obtain the spatial concentration coefficient. S i ; In S4, the spatial concentration factor S i This indicates the density distribution of acoustic emission event coordinates within the rock mass space, and the spatial concentration factor. S i Satisfy the following calculation formula: in, m The number of neighbors on the rock sample plane. The upper and lower rocks are respectively the first k Number of acoustic emission location points within a neighborhood The upper and lower rocks are respectively the first k The average distance between acoustic emission location points within a neighborhood; S5: Obtain acoustic emission activity evaluation indicators based on acoustic emission impact, ring count, and energy data. E i ; In S5, the acoustic emission activity evaluation index E i Used to quantify the activity and severity of microcracks, and as an evaluation index for acoustic emission activity. E i Satisfy the following calculation formula: in, They are time points i The number of impacts, ring count, and energy of acoustic emissions. These represent the number of impacts, ring count, and energy emitted at the peak acoustic emission point, respectively. S6: Based on the localization coefficient of strain on the structural surface J i Time concentration factor T i Spatial Concentration Factor S i Harmony Emission Activity Evaluation Index E i Damage quantification parameters of jointed rock mass were calculated. Q i ; In S6, the damage quantification parameters of the jointed rock mass Q i Damage quantification comprehensively considers rock blocks and structural planes, including local deformation of structural planes, spatiotemporal distribution of microcracks, and the activity and severity of microcracks, and includes damage quantification parameters of jointed rock masses. Q i Satisfy the following calculation formula: 。 2. The method for quantifying damage in jointed rock masses based on acoustic emission and DIC data according to claim 1, characterized in that, The acquisition of raw acoustic emission, image, and stress data in S1 specifically includes the following steps: a loading system and an acoustic emission and image acquisition system are run synchronously on a rock mass sample containing a single through joint. On one side of the sample, a camera is used to acquire images of the sample in real time. On the other side, four sensors are arranged on the upper and lower rock blocks to acquire acoustic emission data of the two rock blocks, including waveform data and event location data.

3. The method for quantifying damage in jointed rock masses based on acoustic emission and DIC data according to claim 2, characterized in that, In step S2, the global strain of the rock mass is calculated using the DIC technique to obtain the strain localization coefficient of the structural surface. J i Specifically, the steps include: taking four characteristic points on the central axis of the sample, with two characteristic points at the center of the upper and lower rock blocks and two characteristic points at the center of the strain localization zone of the structural surface; and calculating the strain localization coefficient of the structural surface using the maximum principal strain and shear strain at the four characteristic points. J i .

4. An electronic device, characterized in that, include: A memory and a processor, wherein the processor is used to execute a computer management program stored in the memory to implement the jointed rock mass damage quantification method based on acoustic emission and DIC data as described in any one of claims 1 to 3 above.

5. A computer-readable storage medium storing computer management programs thereon, characterized in that: When the computer management program is executed by the processor, it implements the jointed rock mass damage quantification method based on acoustic emission and DIC data as described in any one of claims 1 to 3.

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