Identification Of Discontinuities And 3D Numerical Analysis Of Openpit Mine Slope Based On UAV Photography

One of the important research topics in the fields of engineering geology and geological disasters is the stability evaluation of high and steep slopes in large open-pit mines.The structural plane of the rock mass plays an important control role in the deformation and failure mode and strength characteristics of the rock mass under certain load conditions.Therefore,engineering geologists need to quickly,comprehensively and accurately obtain structural plane information data,which is of great significance to the stability evaluation of high and steep open-pit mine slopes.Nowadays,today's society has become the information age.With the rapid development of Internet technology,intelligent,digital,and humanized facility technologies continue to appear and improve.In order to further realize the intelligence and digitization of geological surveys,reduce the intensity of traditional geological surveys,simplify the survey workflow while improving Safety,this article proposes a quick,safe and accurate survey method based on drone photography.In this process,this article first starts with drone photography and uses drones to obtain slope point cloud data;then,a set of point cloud data-based discontinuities intelligent recognition and interpretation methods are proposed to obtain slope rock Information about the occurrence,trace length,and spacing of the discontinuities;secondly,the 3D point cloud model can be easily imported into 3DEC through the combined method of surface reconstruction and "Rhino-Griddle-3DEC" to establish the slope Combining the aforementioned statistical information of discontinuities to construct a discrete fracture network cutting slope model for numerical calculation and analysis;finally,this technical process is applied to the Dexing Yinshan Copper Mine in Jiangxi Province for analysis.In a word,The paper draws the following conclusions:(1)According to the basic theories of computer vision,including commonly used coordinate systems and their mutual conversion relations,epipolar geometry,etc.,combined with the standardized UAV photography process,the UAV image is processed by the 3D reconstruction method based on the Sf M method It summarizes and summarizes the point cloud data.The drone photography process mainly includes:the selection of drones;site survey of the flight site before aerial photography,finding safe landing points and reasonable planning of flight routes;to ensure accuracy,choose3?5 control points on the ground;Locally small areas,obstructed by obstacles,or almost vertical areas where the impact of aerial photography is difficult to obtain,manual operation is used for on-site operations;finally,the aerial photos are checked for data.Taking the slopes of Zone II and Zone III-B as examples,the 3D reconstruction method based on the Sf M method is adopted to process the aerial photos with the help of Context Capture software to obtain their respective slope 3D point cloud data.(2)Propose a set of point cloud-based intelligent identification of discontinuities and information geometry interpretation process: After obtaining the point cloud,identify the same group of discontinuities and their occurrence by calculating the normal vector of each point,which is the dominant occurrence;Clustering segmentation,identifying a single discontinuities and calculating the geometric parameters of the discontinuities such as the occurrence and position,trace length and spacing of the single discontinuities.Taking the slopes of Zone II and Zone III-B as examples,the discontinuities information of each zone is identified and interpreted for statistical analysis.Finally,take the ?-B area as an example to compare the interpretation results of the discontinuities with the manual measurement results.The comparison results show that the error is small,which proves that this method is reliable.(3)Propose a set of 3D numerical modeling methods based on point clouds,and use the joint method of commercial software Geomagic Studio and "Rhino – Griddle-3DEC" to import 3D point cloud models into 3DEC to construct 3D numerical models of slopes,and then use The discontinuities statistics information establishes a discrete fracture network and cuts the slope model,and finally performs numerical calculation and analysis.Apply this method to ?-B area,construct a three-dimensional numerical model of the slope for calculation and analysis.The results show that the slope in zone?-B(the high slope at the 120 m platform in the east)has poor stability under natural conditions when only its own weight is considered,and the displacement is large,up to2.385 m.The main displacement of the slope is The vertical subsidence and sliding to the empty surface are dominant.The calculation results are basically consistent with the field survey results,which demonstrates that the numerical simulation method has high accuracy.