The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods ...The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.展开更多
为提高岩体结构面信息获取精度,基于结构面三维点云数据,改进DBSCAN(density-based spatial clustering of applications with noise)密度聚类算法。利用k近邻算法与基于密度比S的评价准则划分出不同密度点云区域以自适应设置参数ε并...为提高岩体结构面信息获取精度,基于结构面三维点云数据,改进DBSCAN(density-based spatial clustering of applications with noise)密度聚类算法。利用k近邻算法与基于密度比S的评价准则划分出不同密度点云区域以自适应设置参数ε并分析点云法向量,引入法向量夹角阈值T判断属于同组结构面的点集并用相同颜色显示。本研究讨论了参数最优化组合对识别结果的影响,实现优势结构面与产状赤平投影的快速分析。研究结果能够为结构面信息的智能化高效测量提供一种可靠的应用方法。展开更多
基金This work was supported by the National Nature Science Foundation of China(Grant Nos.42177139 and 41941017)the Natural Science Foundation Project of Jilin Province,China(Grant No.20230101088JC).The authors would like to thank the anonymous reviewers for their comments and suggestions.
文摘The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.
文摘为提高岩体结构面信息获取精度,基于结构面三维点云数据,改进DBSCAN(density-based spatial clustering of applications with noise)密度聚类算法。利用k近邻算法与基于密度比S的评价准则划分出不同密度点云区域以自适应设置参数ε并分析点云法向量,引入法向量夹角阈值T判断属于同组结构面的点集并用相同颜色显示。本研究讨论了参数最优化组合对识别结果的影响,实现优势结构面与产状赤平投影的快速分析。研究结果能够为结构面信息的智能化高效测量提供一种可靠的应用方法。
