Landslide tension crack development depth evaluation method, computer readable medium and equipment

Abstract

The invention discloses a landslide tension crack development depth evaluation method, a computer readable medium and equipment, and relates to the field of landslide tension crack development depth evaluation. Comprising the steps that vibration monitoring equipment is arranged in a landslide mass trailing edge crack area, and rock-soil mass vibration response data are collected in real time; extracting a first-order inherent frequency of the vibration signal based on a spectral analysis method, and determining a modal order; the first-order inherent frequency change rate is calculated, and the change of the modal order is calculated; and evaluating the development depth of the tension crack in combination with the first-order inherent frequency change rate and the modal order change. Compared with traditional drilling detection or indirect calculation through the crack opening degree, the method can directly invert the crack depth evolution law through the dynamic response characteristics of the vibration mode parameters, avoids secondary damage to a rock-soil structure, solves the limitation of traditional monitoring methods on hidden crack depth evaluation, and improves the detection accuracy. The accuracy and timeliness of landslide stability evaluation are remarkably improved, and the method is suitable for monitoring and early warning of traction-type progressive damage of the landslide.

Description

Technical Field

[0001] The present invention relates to the field of landslide stability assessment, and in particular to a method for assessing the development depth of tensile cracks in a landslide, and a computer-readable medium and device. Background Art

[0002] Traditional methods for assessing the depth of tensile cracks in landslides rely primarily on surface crack geometry measurement, borehole exploration, or geophysical exploration techniques, all of which have significant limitations. Surface monitoring (e.g., crack width and length measurements) can only indirectly infer shallow crack extension and exhibits a lag, failing to capture deeper damage. While borehole exploration (e.g., inclinometers and strain gauge deployment) can obtain localized deep data, its invasive nature easily damages the geotechnical structure, is costly, and hinders large-scale continuous monitoring. Geophysical exploration techniques (e.g., geological radar and resistivity imaging) are limited by insufficient resolution and environmental interference, resulting in low sensitivity to millimeter-scale cracks. Furthermore, they rely on periodic manual detection and lack dynamic tracking capabilities. Furthermore, vibration modal analysis, widely used in structural health monitoring, faces challenges in its applicability to landslides. For example, the correlation between vibration parameters and landslide stability remains unclear, and further research is needed to determine how to apply vibration parameters to landslide stability assessment.

[0003] To address these technical challenges, this paper proposes a non-invasive assessment method based on vibration modal analysis theory and rock and soil damage mechanics, combined with high-precision sensors and dynamic signal analysis algorithms. By collecting real-time landslide vibration response data, extracting the first-order natural frequency change rate and modal order change characteristics, and constructing a vibration parameter-based crack depth assessment method, this method achieves dynamic inversion of hidden crack depths, providing timely, high-precision quantitative data support for landslide stability warning and disaster prevention and control. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for evaluating the development depth of landslide tensile cracks and a computer-readable medium and device, so as to solve the problems of rock and soil structure damage, monitoring hysteresis and insufficient accuracy of hidden crack depth assessment caused by relying on drilling detection or surface parameter calculation in traditional methods.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: a method for evaluating the development depth of landslide tensile cracks, comprising the following steps:

[0006] S1, deploy vibration monitoring equipment in the crack area at the rear edge of the landslide to collect real-time vibration response data of the rock and soil;

[0007] S2, extract the first-order natural frequency of the vibration signal based on the spectrum analysis method and determine the modal order;

[0008] S3, calculate the rate of change of the first-order natural frequency and the change of the modal order;

[0009] S4, the development depth of tension cracks is evaluated by combining the first-order natural frequency change rate and modal order change.

[0010] Preferably, the S1 is specifically:

[0011] A vibration pickup was placed 1 to 2 m away from the slope foot, corresponding to the point where the tensile cracks in the landslide body had the maximum opening and closing degree, to collect vibration time history curves. The collection frequency was 200 Hz, and each collection lasted 10 min.

[0012] Preferably, the vibration pickup is a piezoelectric vibration pickup, a piezoresistive vibration pickup, a capacitive vibration pickup, an electromagnetic vibration pickup, a fiber optic vibration pickup or a laser Doppler vibrometer.

[0013] Preferably, the S2 is specifically:

[0014] S21. Divide the 10-minute vibration data into 60 segments by time, with each segment lasting 10 seconds, and calculate the average value of each segment. Average value of 10-minute vibration data Compare the average value of each vibration data segment The mean of the entire data segment Deviation value And calculate the deviation rate when When , the data segment is considered as abnormal data, the abnormal data is removed, and the remaining data is combined into the new data x';

[0015] S22. Using the newly synthesized data x', the Welch method is used to calculate the spectrum. The parameters of the Welch method are set to 10 seconds for each vibration data segment, 2 seconds for the number of overlapping samples, and a Hanning window function. The power spectrum is calculated and squared to obtain the spectrum. The frequency corresponding to the first peak in the spectrum is selected as the first-order natural frequency.

[0016] S23. Continue to check the other peaks in the spectrum graph, which correspond to other orders of natural frequencies. The number of peaks in the spectrum graph corresponds to the number of modal orders.

[0017] Preferably, the S3 is specifically:

[0018] S31. The first stable first-order natural frequency after the equipment is installed is taken as the initial first-order natural frequency f0. The first-order natural frequency calculated each time during monitoring is f t , then the first-order natural frequency change value Δf=|f t -f0|, the rate of change of the first-order natural frequency

[0019] S32. The number of peaks at the first stable state after the equipment is installed is taken as the initial modal order n0, and the modal order during monitoring is n t , if n t -n0≠0 means that the modal order n has changed.

[0020] Preferably, the S4 is specifically:

[0021] The development of tensile cracks will eventually split the landslide body, causing changes in the structure and boundary conditions of the landslide system, thereby causing changes in the first-order natural frequency and modal order. The development depth of the tensile cracks is evaluated based on the change rate of the first-order natural frequency and the modal order.

[0022] For soil landslides:

[0023] Then the development depth of tension cracks accounts for less than 40%;

[0024] Then 40%≤tensile crack development depth ratio<60%;

[0025] Then 60%≤tensile crack development depth ratio<80%;

[0026] Or if the modal order n changes, the development depth of the tension crack accounts for ≥80%;

[0027] For rock slides:

[0028] Then the development depth of tension cracks accounts for less than 40%;

[0029] Then 40%≤tensile crack development depth ratio<60%;

[0030] Then 60%≤tensile crack development depth ratio<80%;

[0031] Or if the modal order n changes, the development depth of tension cracks accounts for ≥80%.

[0032] Preferably, the computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the above method.

[0033] Preferably, the computer device includes a memory, a processor, and a program stored and executable on the memory, and the program implements the steps of the above method when executed by the processor.

[0034] The beneficial effects of the present invention include: real-time acquisition of rock and soil response data through non-invasive vibration monitoring, extraction of first-order natural frequency change rate and modal order change characteristics through spectrum analysis, and construction of a dynamic inversion model for crack depth, thus overcoming the destructive limitations of traditional borehole detection and the hysteresis bottleneck of surface monitoring; innovative fusion of dual-parameter indicators (first-order natural frequency change rate to sensitively capture damage, modal order jump to identify critical states) to achieve accurate assessment of hidden crack depth; segmented screening and Welch spectrum optimization algorithm to suppress noise, and differentiated adaptation of soil / rock landslide assessment thresholds, significantly improving monitoring reliability in complex environments and providing highly efficient and low-cost technical support for early warning of progressive landslide damage. The system can be widely used to assess the degree of crack development and stability of slopes in water conservancy and hydropower projects, high and steep slopes, and highway and railway slopes. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 1 is a schematic diagram of the execution flow of a method for evaluating the development depth of tensile cracks in landslides provided by an embodiment of the present invention;

[0036] Figure 2 is a partial vibration acceleration time history graph collected by an embodiment of the present invention;

[0037] Figure 3 is an initial spectrum diagram of an embodiment of the present invention;

[0038] Figure 4 This is a daily monitoring spectrum diagram of an embodiment of the present invention;

[0039] Figure 5 4 is a first-order natural frequency change curve diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] Example 1

[0042] This embodiment provides a method for evaluating the depth of landslide tensile crack development. The execution process of the method is as follows: Figure 1 As shown, the following steps are included:

[0043] S1, deploy vibration monitoring equipment in the crack area at the rear edge of the landslide to collect real-time vibration response data of the rock and soil;

[0044] Specifically, in this embodiment, the above S1 implementation process is as follows:

[0045] S11, a vibration pickup is placed 1 to 2 meters away from the slope foot side, corresponding to the point where the tension and closure degree of the tensile cracks in the landslide body is the largest. The vibration pickups are piezoelectric vibration pickups, piezoresistive vibration pickups, capacitive vibration pickups, electromagnetic vibration pickups, fiber optic vibration pickups, and laser Doppler vibrometers.

[0046] S12, collect vibration time history curves, with a collection frequency of 200 Hz and each collection time of 10 minutes.

[0047] S2, extract the first-order natural frequency of the vibration signal based on the spectrum analysis method and determine the modal order;

[0048] Specifically, in this embodiment, the above S2 implementation process is as follows:

[0049] S21, divide the 10-minute vibration data into 60 segments according to time, each segment is 10 seconds, and calculate the average value of each segment Average value of 10-minute vibration data Compare the average value of each vibration data segment The mean of the entire data segment Deviation value And calculate the deviation rate when When , the data segment is considered as abnormal data. Remove the abnormal data and combine the remaining data into the new data x'.

[0050] S22, use the synthesized new data x' to calculate the spectrum diagram using the Welch method. The parameters of the Welch method are set to 10s for each small segment of vibration data, 2s for the number of overlapping samples, and the Hanning window function. The power spectrum is calculated and squared to obtain the spectrum diagram. The frequency corresponding to the first peak in the spectrum diagram is selected as the first-order natural frequency.

[0051] S23, continue to check other peaks in the spectrum graph, which correspond to other orders of natural frequencies. The number of peaks in the spectrum graph corresponds to the number of modal orders.

[0052] S3, calculate the rate of change of the first-order natural frequency and the change of the modal order;

[0053] Specifically, in this embodiment, the above S3 implementation process is as follows:

[0054] S31, the first stable first-order natural frequency after the equipment is installed is taken as the initial first-order natural frequency f0, and the first-order natural frequency calculated each time during monitoring is f t , then the first-order natural frequency change value Δf=|f t -f0|, the rate of change of the first-order natural frequency

[0055] S32, the number of peaks that are stable for the first time after the equipment is installed is taken as the initial modal order n0, and the modal order during monitoring is n t , if n t -n0≠0 means that the modal order n has changed.

[0056] S4, evaluates the development depth of tension cracks by combining the first-order natural frequency change rate and modal order change;

[0057] Specifically, in this embodiment, the development depth of the tensile crack is evaluated based on the change rate of the first-order natural frequency and the change of the modal order:

[0058] For soil landslides:

[0059] Then the development depth of tension cracks accounts for less than 40%;

[0060] Then 40%≤tensile crack development depth ratio<60%;

[0061] Then 60%≤tensile crack development depth ratio<80%;

[0062] Or if the modal order n changes, the development depth of tension cracks accounts for ≥80%.

[0063] For rock slides:

[0064] Then the development depth of tension cracks accounts for less than 40%;

[0065] Then 40%≤tensile crack development depth ratio<60%;

[0066] Then 60%≤tensile crack development depth ratio<80%;

[0067] Or if the modal order n changes, the development depth of tension cracks accounts for ≥80%.

[0068] Second embodiment

[0069] The implementation process and implementation effect of the method of the present invention are described in detail below in conjunction with a practical application example of the technical solution of the present invention. Specifically, the implementation process of the method includes the following steps:

[0070] S1, deploy vibration monitoring equipment in the crack area at the rear edge of the landslide to collect real-time vibration response data of the rock and soil;

[0071] Specifically, in this embodiment, the above S1 implementation process is as follows:

[0072] S11, a piezoelectric vibration pickup was placed 1.2 m away from the slope foot, corresponding to the point where the tensile crack of the landslide body has the largest tension and closure degree.

[0073] S12, collect vibration time history curves, the collection frequency is 200 Hz, and each collection time is 10 minutes. Figure 2 shown.

[0074] S2, extract the first-order natural frequency of the vibration signal based on the spectrum analysis method and determine the modal order;

[0075] Specifically, in this embodiment, the above S2 implementation process is as follows:

[0076] S21, divide the 10-minute vibration data into 60 segments according to time, each segment is 10 seconds, and calculate the average value of each segment Average value of 10-minute vibration data Compare the average value of each vibration data segment The mean of the entire data segment Deviation value And calculate the deviation rate when When , the data segment is considered as abnormal data. Remove the abnormal data and combine the remaining data into the new data x'.

[0077] S22, use the synthesized new data x' to calculate the spectrum diagram using the Welch method. The parameters of the Welch method are set to 10s for each small segment of vibration data, 2s for the number of overlapping samples, and the Hanning window function. The power spectrum is calculated and squared to obtain the spectrum diagram. The frequency corresponding to the first peak in the spectrum diagram is selected as the first-order natural frequency.

[0078] S23, continue to check other peaks in the spectrum graph, which correspond to other orders of natural frequencies. The number of peaks in the spectrum graph corresponds to the number of modal orders.

[0079] S3, calculate the rate of change of the first-order natural frequency and the change of the modal order;

[0080] Specifically, in this embodiment, the above S3 implementation process is as follows:

[0081] S31, the first stable first-order natural frequency after the equipment is installed is taken as the initial first-order natural frequency f0, such as Figure 3 As shown, the first-order natural frequency calculated each time during monitoring is f t ,like Figure 4 As shown, the first-order natural frequency change curve within a period of time is as follows Figure 5 As shown, the first-order natural frequency change value Δf=|f t-f0|, the rate of change of the first-order natural frequency

[0082] S32, the number of peaks that are stable for the first time after the equipment is installed is taken as the initial modal order n0, and the modal order during monitoring is n t , if n t -n0≠0 means that the modal order n has changed.

[0083] S4, evaluates the development depth of tension cracks by combining the first-order natural frequency change rate and modal order change;

[0084] Specifically, in this embodiment, the landslide is a soil landslide, and the development depth of the tensile crack is evaluated based on the first-order natural frequency change rate and the modal order change:

[0085] Then the development depth of tension cracks accounts for less than 40%;

[0086] Then 40%≤tensile crack development depth ratio<60%;

[0087] Then 60%≤tensile crack development depth ratio<80%;

[0088] Or if the modal order n changes, the development depth of tension cracks accounts for ≥80%.

[0089] according to Figure 5 As well as the evaluation rule, the first-order natural frequency change rate is Right now The modal order n has not changed, so it can be judged that the development depth of the tensile cracks is between 60% and 80%. The tensile cracks have developed to a certain extent, and the landslide may be in a weakly stable state.

[0090] By adopting the above-mentioned technical solution disclosed in the present invention, secondary damage to the landslide structure caused by drilling is avoided, and non-destructive monitoring is achieved; noise is suppressed by segmented data screening and Welch method spectrum optimization to improve data reliability; the depth of hidden cracks is inverted by multi-parameter fusion (natural frequency and modal order), solving the indirect limitations of surface parameter estimation; it is compatible with the differentiated model of soil / rock landslides and adapts to long-term stable monitoring in complex environments, providing a highly timely and high-precision scientific basis for landslide stability warning and engineering decision-making.

[0091] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in whole or in part in the form of a computer program product, the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL) or wireless (e.g., infrared, wireless, microwave, etc.)) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape) or an optical medium.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the development depth of landslide tensile cracks, characterized in that: The following steps are involved: S1. Deploy vibration monitoring equipment in the crack area at the rear edge of the landslide to collect real-time vibration response data of the rock and soil; S2. Extract the first-order natural frequency of the vibration signal based on spectrum analysis and determine the modal order; S3. Calculate the rate of change of the first-order natural frequency and the change of the modal order; S4. Evaluate the development depth of tensile cracks by combining the first-order natural frequency change rate and modal order change.

2. The method for evaluating the development depth of landslide tensile cracks according to claim 1, characterized in that: Said S1 is: placing a vibration pickup 1 to 2 m away from the slope foot side corresponding to the point where the tension crack of the landslide body has the maximum opening and closing degree to collect vibration time history curves, with a collection frequency of 200 Hz and a collection time of 10 minutes each time.

3. The method for evaluating the development depth of landslide tensile cracks according to claim 2, characterized in that: The vibration pickup is a piezoelectric vibration pickup, a piezoresistive vibration pickup, a capacitive vibration pickup, an electromagnetic vibration pickup, an optical fiber vibration pickup or a laser Doppler vibrometer.

4. The method for evaluating the development depth of landslide tensile cracks according to claim 1, characterized in that: The S2 includes: S21. Divide the 10-minute vibration data into 60 segments by time, with each segment lasting 10 seconds, and calculate the average value of each segment. Average value of 10-minute vibration data Compare the average value of each vibration data segment The mean of the entire data segment Deviation value And calculate the deviation rate when When , the data segment is considered as abnormal data, the abnormal data is removed, and the remaining data is combined into the new data x'; S22. Using the newly synthesized data x', the Welch method is used to calculate the spectrum. The parameters of the Welch method are set to 10 seconds for each vibration data segment, 2 seconds for the number of overlapping samples, and a Hanning window function. The power spectrum is calculated and squared to obtain the spectrum. The frequency corresponding to the first peak in the spectrum is selected as the first-order natural frequency. S23. Continue to check the other peaks in the spectrum graph, which correspond to other orders of natural frequencies. The number of peaks in the spectrum graph corresponds to the number of modal orders.

5. The method for evaluating the development depth of landslide tensile cracks according to claim 1, wherein: The S3 includes: S31. The first stable first-order natural frequency after the equipment is installed is taken as the initial first-order natural frequency f0. The first-order natural frequency calculated each time during monitoring is f t , then the first-order natural frequency change value Δf=|f t -f0|, the rate of change of the first-order natural frequency S32. The number of peaks at the first stable state after the equipment is installed is taken as the initial modal order n0, and the modal order during monitoring is n t , if n t -n0≠0 means that the modal order n has changed.

6. The method for evaluating the development depth of landslide tensile cracks according to claim 1, characterized in that: The S4 includes: the development of the tensile crack will eventually split the landslide body, causing changes in the structure and boundary conditions of the landslide system, thereby causing changes in the first-order natural frequency and modal order, and evaluating the development depth of the tensile crack based on the change rate of the first-order natural frequency and the modal order; For soil landslides: Then the development depth of tension cracks accounts for less than 40%; Then 40%≤tensile crack development depth ratio<60%; Then 60%≤tensile crack development depth ratio<80%; Or if the modal order n changes, the development depth of the tension crack accounts for ≥80%; For rock slides: Then the development depth of tension cracks accounts for less than 40%; Then 40%≤tensile crack development depth ratio<60%; Then 60%≤tensile crack development depth ratio<80%; Or if the modal order n changes, the development depth of tension cracks accounts for ≥80%.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 6.

8. A computer device, characterized in that: The computer device includes a memory, a processor, and a program stored and executable on the memory, and when the program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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