Rock slope kinematics analysis method based on unmanned aerial vehicle digital rock field model

Abstract

The invention provides a rock slope kinematics analysis method based on an unmanned aerial vehicle digital rock field model, which combines manual extraction of discontinuous data from the digital rock field model and kinematics analysis performed by using an automatic algorithm, and the algorithm upgrades and updates a traditional Markland test. In complex geological environments, manual mapping provides more statistically robust and geologically reliable discontinuity direction measurements, which are verified by the user's professional skills. According to the new algorithm, the 3D space relation between the discontinuous network and the rock slope is combined, so that kinematics characterization can be carried out on the rock cliff more accurately and specifically, and the key plane and the potential rock mass damage volume are emphasized through 3D visualization. The new method significantly reduces the time, workload and cost of an engineering project, allowing quantitative definition of potential unstable regions by rapid analysis.

Description

Technical Field

[0001] The present invention belongs to the field of geotechnical engineering, relates to rock slope motion analysis, and specifically relates to a rock slope kinematic analysis method based on an unmanned aerial vehicle digital rock field model. Background Art

[0002] Affected by various internal and external dynamics such as geological causes, tectonic background, mineral characteristics, and climatic conditions, the rock slopes have developed internal joints and fissures, and the rock mass presents a "brick-like" feature of intricate cutting. Most of them are in an unstable state. High-level broken and dangerous rock collapse disasters occur frequently in the area, seriously threatening the safety of tourists' lives and property. Existing studies have shown that structural surfaces are the main cause of frequent rock slope disasters. Therefore, recognizing the geological background and identifying the spatial distribution characteristics of structural surfaces have become the primary prerequisites for winning the battle of disaster prevention and mitigation.

[0003] The use of engineering measures to transform the geological environment can effectively achieve the organic combination of engineering and environment. For the dual considerations of personnel safety and accurate survey results, more and more technical means are being used in actual projects. UAV aerial survey has outstanding advantages, and with the continuous innovation of aerial photography technology, it is becoming more and more popular among geologists. This paper proposes a kinematic analysis of rock slopes based on UAV digital rock field models and a horizontal close-flying UAV aerial survey method. On the basis of reasonable route planning, a high-precision surface digital model can be quickly obtained through powerful post-processing software, and a three-dimensional model of the spatial structural surface for rock slope stability analysis can be established through post-interpretation and classification statistics. It is expected to provide a reference for the survey work of such geological structure slope emergency rescue projects. Summary of the invention

[0004] The present invention provides a kinematic analysis method for rock slopes based on an unmanned aerial vehicle (UAV) digital rock field model. This analysis method targets the characteristics of large, high and steep rock slopes and adopts a fast, convenient, high-precision and widely applicable method for acquiring spatial information of slope surface structural surfaces based on UAV technology.

[0005] In order to realize the above technical features, the object of the present invention is achieved as follows: a rock slope kinematic analysis method based on an unmanned aerial vehicle digital rock field model, comprising: Photogrammetry using drones to obtain information about distance, overlap, number of images acquired and area covered on rock slopes; Using image data acquired from drone photogrammetry, high-resolution 3D point clouds and digital surface models are generated through software processing; A method for performing three-dimensional discontinuity mapping on a digital rock field model, including using software for visual analysis and data collection to obtain a three-dimensional discontinuity map; Manually identify and draw discontinuities on the digital rockfield model, and collect information on the orientation, size, and location of discontinuities by manual methods; Verify the accuracy and reliability of data extracted from the digital rockfield model by comparing it with site-based scanline measurements; Upgrading the traditional Markland test using the ROKA algorithm to perform kinematic analysis by taking into account the actual geometry of the rock slope and the spatial distribution of discontinuities; Quantitative analysis of potential failure modes of rock slopes using the ROKA algorithm and identification of possible critical discontinuities and potential unstable areas; The analysis results are presented through 3D visualization techniques, including the identification of potential unstable areas and the location of critical discontinuities.

[0006] The UAV photogrammetry information includes the image of the construction area and the latitude and longitude, elevation, and shooting posture of the UAV; the UAV photogrammetry information is combined with the auxiliary positioning information to generate an absolute coordinate system and the slope surface feature points located in the absolute coordinate system; the construction area image obtained by aerial photography is registered, segmented, and reconstructed to generate the three-dimensional model of the slope in the absolute coordinate system.

[0007] The three-dimensional slope model is a model established along certain time nodes. For the problems that may arise during the movement of the rock slope, probability calculation is performed through the information management platform to predict the probability of possible geological disasters, obtain predicted disaster information, and view the predicted disaster information through the user terminal.

[0008] After each measurement, analysis and processing using drone photography, the rock slope movement process report is generated, viewed and downloaded through the user terminal.

[0009] Small drones are used to acquire data, combined with Pix4dmapper image information processing software to assist in modeling, and high-precision three-dimensional digital models are used to interpret the slope structural surface information, including: occurrence, trace length, and density.

[0010] It includes the following core links: ① Setting the flight path and taking a two-dimensional image of the research object; ② Obtaining the projection matrix through camera calibration, feature point extraction, and Sift matching algorithm and epipolar geometry principle; ③ Combining the correspondence between the two-dimensional image spatial information and the real three-dimensional space of the research object, the feature points in the two-dimensional image that meet the matching rules are mapped to the three-dimensional space coordinate system to form a three-dimensional point cloud; ④ Performing adjustment and denoising to improve the restoration of the three-dimensional model.

[0011] It includes: a measurement system, an information management platform, and a user terminal; the measurement system includes a remote sensing satellite, a drone, and an auxiliary positioning device; the information management platform includes a ROKA algorithm and 3D visualization technology.

[0012] The unmanned aerial vehicle comprises a high-definition camera, a positioning system, a first information transceiver module, a sensor module, and a flight control system; the user terminal comprises a third information transceiver module, a display module, and a second storage module.

[0013] The UAV operator terminal is used to remotely control the UAV.

[0014] A kinematic analysis method for rock slope based on UAV digital rock field model specifically includes the following steps: Step 1: Prepare photogrammetry equipment, use a small drone to acquire data, and use Pix4dmapper image information processing software to assist in modeling, to obtain the distance, overlap, number of acquired images, and coverage area of ​​the rock slope; Step 2: Route layout. According to the structural characteristics of the slope, and to ensure that the resolution and matching number of the structural unit pixel points at the cavity meet the accuracy requirements, a new horizontal approach flight route layout scheme based on high-precision modeling is adopted; during the shooting process, the route is parallel to the slope direction, with a straight route. For engineering slopes with significant mountain space differences, a partition or arc flight method is adopted; Step 3: Establish a digital rock field model. After taking aerial photos according to the scheme described in the previous section, the obtained aerial photos can be reasonably screened and the Pix4dmapper algorithm program can be used to perform pixel matching operations and convert two-dimensional pixels into point clouds with three-dimensional spatial information characteristics. Further adjustment and denoising can be performed to obtain a refined three-dimensional digital point cloud model that can be directly used for joint statistical interpretation. Step 4: Further analysis, using the ROKA algorithm and 3D visualization technology, collects the orientation, size and location information of the rock slope discontinuities and identifies possible critical discontinuities and potential unstable areas; Step 5: Geological disaster prediction: For the problems that may arise during the movement of rock slopes, probability calculations are performed through the information management platform to predict the probability of possible geological disasters and obtain predicted disaster information.

[0015] Beneficial effects of the present invention: 1. The present invention uses digital rock field modeling technology to extract the spatial distribution and orientation of discontinuities (such as cracks, faults, and bedding) from UAV photogrammetry data.

[0016] 2. The present invention applies the ROKA algorithm to perform a more detailed kinematic analysis of the rock slope, taking into account the actual geometric shape of the rock slope and the spatial distribution of discontinuities, and presents the analysis results of the ROKA algorithm, including quantitative data of possible critical discontinuities and potential unstable areas in the rock slope.

[0017] 3. The present invention uses 3D visualization technology to display the stability analysis results of rock slopes, including the spatial distribution of key discontinuities and potential unstable volumes.

[0018] 4. The present invention improves the efficiency and accuracy of data processing through algorithm optimization and software tools.

[0019] 5. The new method adopted by this invention significantly reduces the time, workload and cost of engineering projects, combining traditional geological survey methods with modern technologies (such as UAV photogrammetry and 3D modeling) to achieve a more comprehensive rock slope stability assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 Flow chart for rock slope photography.

[0022] Figure 2 Information management platform operation flow chart.

[0023] Figure 3 Flowchart of rock slope motion analysis based on drone photography. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0025] Embodiment 1: like Figure 1-3 As shown, a rock slope kinematic analysis method based on an unmanned aerial vehicle digital rock field model is characterized by comprising the following steps: Unmanned aerial vehicle (UAV) photogrammetry, using drones to obtain information about distance, overlap, number of images acquired and area covered on rock slopes; Using image data acquired from UAV photogrammetry, processed by Agisoft Metashape software, high-resolution three-dimensional (3D) point clouds and digital surface (DOM) models are generated; A method for performing three-dimensional discontinuity mapping on a digital rock field model, including using CloudCompare software for visual analysis and data collection to obtain a 3D discontinuity map; The process of manually identifying and mapping discontinuities (e.g., fractures, faults, bedding) on ​​digital rockfield models, and how to collect information on the orientation, size, and location of discontinuities through manual methods; Verify the accuracy and reliability of data extracted from the digital rockfield model by comparing it with site-based scanline measurements; Working principle of the ROKA (ROck slope Kinematic Analysis) algorithm, an automated algorithm that upgrades the traditional Markland test to perform kinematic analysis by taking into account the actual geometry of the rock slope and the spatial distribution of discontinuities; Quantitatively analyze potential failure modes of rock slopes (such as plane sliding, buckling and wedge sliding) using the ROKA algorithm and identify possible critical discontinuities and potential unstable areas; 3D visualization technology is used to present the analysis results, including the identification of potential unstable areas and the location of critical discontinuities.

[0026] Furthermore, the aerial photography information includes an image of the construction area and the latitude and longitude, elevation, and shooting posture of the drone. The aerial photography information is combined with the auxiliary positioning information to generate an absolute coordinate system and slope surface feature points located in the absolute coordinate system; the construction area image acquired by aerial photography is registered, segmented, and reconstructed to generate a three-dimensional model of the slope in the absolute coordinate system.

[0027] Furthermore, the three-dimensional slope model is a model established along certain time nodes. For problems that may arise during the movement of the rock slope, probability calculations are performed through the information management platform to predict the probability of possible geological disasters, obtain predicted disaster information, and view the predicted disaster information through the user terminal.

[0028] Furthermore, after each UAV photogrammetry, analysis and processing, the rock slope movement process report is generated, viewed and downloaded through the user terminal.

[0029] Furthermore, 4Pro small UAV was used for data acquisition, combined with Pix4dmapper image information processing software to assist modeling, and the slope structural surface information (such as occurrence, trace length, density, etc.) was interpreted through a high-precision three-dimensional digital model.

[0030] Furthermore, it includes the following core links: ① setting the flight path and taking a two-dimensional image of the research object; ② obtaining the projection matrix through camera calibration, feature point extraction and based on the Sift matching algorithm and epipolar geometry principle; ③ combining the correspondence between the two-dimensional image spatial information and the real three-dimensional space of the research object, mapping the feature points in the two-dimensional image that meet the matching rules into the three-dimensional space coordinate system to form a three-dimensional point cloud; ④ performing adjustment and denoising to improve the restoration of the three-dimensional model.

[0031] Furthermore, it includes a measurement system, an information management platform, and a user terminal; the measurement system includes a remote sensing satellite, an unmanned aerial vehicle, and an auxiliary positioning device; the information management platform includes a ROKA algorithm and 3D visualization technology.

[0032] Furthermore, the drone includes a high-definition camera, a positioning system, a first information transceiver module, a sensor module, and a flight control system; the user terminal includes a third information transceiver module, a display module, and a second storage module.

[0033] Embodiment 2: A kinematic analysis method for rock slope based on UAV digital rock field model specifically includes the following steps: Step 1: Prepare photogrammetry equipment, use a small drone to acquire data, and use Pix4dmapper image information processing software to assist in modeling, to obtain the distance, overlap, number of acquired images, and coverage area of ​​the rock slope; Step 2: Route layout. According to the structural characteristics of the slope, and to ensure that the resolution and matching number of the structural unit pixel points at the cavity meet the accuracy requirements, a new horizontal approach flight route layout scheme based on high-precision modeling is adopted; during the shooting process, the route is parallel to the slope direction, with a straight route. For engineering slopes with significant mountain space differences, a partition or arc flight method is adopted; Step 3: Establish a digital rock field model. After taking aerial photos according to the scheme described in the previous section, the obtained aerial photos can be reasonably screened and the Pix4dmapper algorithm program can be used to perform pixel matching operations and convert two-dimensional pixels into point clouds with three-dimensional spatial information characteristics. Further adjustment and denoising can be performed to obtain a refined three-dimensional digital point cloud model that can be directly used for joint statistical interpretation. Step 4: Further analysis, using the ROKA algorithm and 3D visualization technology, collects the orientation, size and location information of the rock slope discontinuities and identifies possible critical discontinuities and potential unstable areas; Step 5: Geological disaster prediction: For the problems that may arise during the movement of rock slopes, probability calculations are performed through the information management platform to predict the probability of possible geological disasters and obtain predicted disaster information.

Claims

1. A rock slope kinematic analysis method based on an unmanned aerial vehicle digital rock field model, characterized in that: include: Photogrammetry using drones to obtain information about distance, overlap, number of images acquired and area covered on rock slopes; Using image data acquired from drone photogrammetry, high-resolution 3D point clouds and digital surface models are generated through software processing; A method for performing three-dimensional discontinuity mapping on a digital rock field model, including using software for visual analysis and data collection to obtain a three-dimensional discontinuity map; Manually identify and draw discontinuities on the digital rockfield model, and collect information on the orientation, size, and location of discontinuities by manual methods; Verify the accuracy and reliability of data extracted from the digital rockfield model by comparing it with site-based scanline measurements; Upgrading the traditional Markland test using the ROKA algorithm to perform kinematic analysis by taking into account the actual geometry of the rock slope and the spatial distribution of discontinuities; Quantitative analysis of potential failure modes of rock slopes using the ROKA algorithm and identification of possible critical discontinuities and potential unstable areas; 3D visualization is used to present analysis results, including the identification of potential unstable areas and the location of critical discontinuities.

2. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized in that: The UAV photogrammetry information includes the image of the construction area and the latitude and longitude, elevation, and shooting posture of the UAV; the UAV photogrammetry information is combined with the auxiliary positioning information to generate an absolute coordinate system and the slope surface feature points located in the absolute coordinate system; the construction area image obtained by aerial photography is registered, segmented, and reconstructed to generate the three-dimensional model of the slope in the absolute coordinate system.

3. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized in that: The three-dimensional slope model is a model established along certain time nodes. For the problems that may arise during the movement of the rock slope, probability calculation is performed through the information management platform to predict the probability of possible geological disasters, obtain predicted disaster information, and view the predicted disaster information through the user terminal.

4. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized in that: After each measurement, analysis and processing using drone photography, the rock slope movement process report is generated, viewed and downloaded through the user terminal.

5. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized by: Small drones are used to acquire data, combined with Pix4dmapper image information processing software to assist in modeling, and high-precision three-dimensional digital models are used to interpret the slope structural surface information, including: occurrence, trace length, and density.

6. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized in that: It includes the following core links: ① Setting the flight path and taking a two-dimensional image of the research object; ② Obtaining the projection matrix through camera calibration, feature point extraction, and Sift matching algorithm and epipolar geometry principle; ③ Combining the correspondence between the two-dimensional image spatial information and the real three-dimensional space of the research object, the feature points in the two-dimensional image that meet the matching rules are mapped to the three-dimensional space coordinate system to form a three-dimensional point cloud; ④ Performing adjustment and denoising to improve the restoration of the three-dimensional model.

7. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized in that: include: Measurement system, information management platform, user terminal; the measurement system includes remote sensing satellite, unmanned aerial vehicle, auxiliary positioning device; The information management platform includes ROKA algorithm and 3D visualization technology.

8. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 7 is characterized by: The unmanned aerial vehicle comprises a high-definition camera, a positioning system, a first information transceiver module, a sensor module, and a flight control system; the user terminal comprises a third information transceiver module, a display module, and a second storage module.

9. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 7 is characterized by: The UAV operator terminal is used to remotely control the UAV.

10. The rock slope kinematic analysis method based on the UAV digital rock field model according to claim 1 is characterized in that: The specific steps include: Step 1: Prepare photogrammetry equipment, use a small drone to acquire data, and use Pix4dmapper image information processing software to assist in modeling, to obtain the distance, overlap, number of acquired images, and coverage area of ​​the rock slope; Step 2: Route layout. According to the structural characteristics of the slope, and to ensure that the resolution and matching number of the structural unit pixel points at the cavity meet the accuracy requirements, a new horizontal approach flight route layout scheme based on high-precision modeling is adopted; during the shooting process, the route is parallel to the slope direction, with a straight route. For engineering slopes with significant mountain space differences, a partition or arc flight method is adopted; Step 3: Establish a digital rock field model. After taking aerial photos according to the scheme described in the previous section, the obtained aerial photos can be reasonably screened and the Pix4dmapper algorithm program can be used to perform pixel matching operations and convert two-dimensional pixels into point clouds with three-dimensional spatial information characteristics. Further adjustment and denoising can be performed to obtain a refined three-dimensional digital point cloud model that can be directly used for joint statistical interpretation. Step 4: Further analysis, using the ROKA algorithm and 3D visualization technology, collects the orientation, size and location information of the rock slope discontinuities and identifies possible critical discontinuities and potential unstable areas; Step 5: Geological disaster prediction: For the problems that may arise during the movement of rock slopes, probability calculations are performed through the information management platform to predict the probability of possible geological disasters and obtain predicted disaster information.

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