基于三维点云建模的矿山边坡稳定性分析

基于无人机摄影测量技术建立矿山边坡精细模型和C++编程实现岩体质量指标空间点云分布,预测边坡岩体稳定性。首先借助三维点云处理软件对模型裁切、去噪、平滑等处理,其次利用Rhinoceros曲面实体建模功能将地质体曲面模型实体化,然后结合Rhinoceros插件Griddle对三维地质体模型网格体划分,最后以FLAC3D软件可识别的*.f3grid文件导出。以绍兴越城区某矿山边坡为例,将模型导入FLAC3D软件计算。结果显示:该矿山岩体受节理影响最大位移位于两矿之间形似"鱼鳍"形状附近,最大位移3.15cm;"鱼鳍"形状附近岩体变形模量为1GPa,质量分数BQ为172.2～263.6,为Ⅴ～Ⅳ级的岩体质量,该区域岩体最大破环概率达到了43%,稳定性系数低于1.0,该计算结果与现场调查结论相吻合,预测了边坡潜在威胁区域,为相关调查研究提供参考依据。

Stability analysis of mine slope based on point cloud modeling

The stability evaluation of mine slope has always been a hot topic in the field of geotechnical engineering. Based on UAV photogrammetry technology, the complex rock mass is described in detail. The 3D point cloud model is established by using sfm-vms algorithm. The 3D point cloud processing software is used to cut, denoise and smooth the 3D point cloud. The powerful surface entity modeling function of rhinoceros is used to transform the geological curve The surface model is materialized, and then combined with rhinoceros plug-in griddle developed by Itasca company, the 3D geological body model mesh is divided. Finally, it is exported to the *. f3grid file recognized by FLAC_^3D. Taking a mine slope in Shaoxing Yuecheng district as an example, the model is imported into FLAC_^3D for calculation. The results show that the maximum displacement of rock mass affected by joints is located near the "fish fin" shape between the two mines, which is close to 3.2 cm. The rock slope surface mainly bears tensile stress, and the rock mass on the slope surface is mainly tensile shear failure. Through the secondary development of the constitutive model by C + + programming, the spatial point cloud distribution calculation of rock mass quality index is realized, and the results show that the rock mass deformation near the "fish fin" shape The shape modulus is 1MPa, and the mass fraction BQ is 172.2 ~ 263.6, which is equivalent to the rock mass quality of grade V ~ IV; the maximum failure probability of rock mass in this area reaches 43%, and the stability coefficient is below 1.0. The calculation results are basically consistent with the field survey conclusion, and the potential threat area of slope is predicted, which provides reference for local relevant departments.