摘要
利用3D激光扫描系统精确测量膏溶角砾岩单轴压缩破坏下岩石断口表面的粗糙形态,结合地理信息系统(GIS)技术,实现岩石断口表面的三维可视化。然后对岩石断口三维几何特性参数进行统计分析,根据频率直方图的分布趋势研究各几何特性参数的分布规律及其随含水率增加的变化规律。最后,研究膏溶角砾岩断口在不同含水率条件下的分形特征,得出岩石断口在不同加载方向上的分维值随含水率增加的变化规律。试验结果表明,断口粗糙高度和坡度的分布近似于正态分布,断口粗糙高度的平均值随着含水率的增加呈线性上升趋势,而断口坡度的平均值随着含水率的增加呈线性下降趋势。通过岩石断口激光扫描试验分析发现,岩石断口的几何特征及分维值与岩石的初始含水状态密切相关,分维可以作为岩石断口几何形态定量描述的参数之一,从而为进一步分析膏溶角砾岩损伤演化过程及其破坏机制提供可靠的试验依据。
By employing 3D laser scanning system, precise measurements of topography on fracture appearance in gypsum breccia under uniaxial compression are taken from which the fracture surface is visualized by using GIS technique. 3D parameters of the geometrical properties, such as asperity height and slope of rough surface are analyzed. The distribution of geometrical properties and its variation with increase of water content are analyzed according to frequency distribution of the histogram. At last, the fractal characteristics of fracture appearance under different water contents are studied. Therefore, the fracture dimensions of appearance under different loading directions and the variation with the increase of water contents are deduced. The test results show that the distributions of asperity height and slope match the normal distribution approximately, and the average of asperity height increases with the increase of water content linearly while the average of slope decreases with the increase of water content linearly. The fractal dimensions of appearance under different loading directions are correlative with water content; as a result, fractal dimension can be one of the important parameters to describe fracture appearance quantitatively. Based on the testing analysis of laser scanning of fracture appearance in gypsum breccia, there are close connections between fractal dimensions of the geometrical properties of fracture appearance and water content under uniaxial compression. The process and mechanics of fracture appearance under uniaxial compression are given as reliable testing basis to further analyze the process of damage evolution and failure mechanism of gypsum breccia.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第A02期3541-3546,共6页
Chinese Journal of Rock Mechanics and Engineering
关键词
岩石力学
地理信息系统
膏溶角砾岩
破裂断口
表面几何特性
分形
分维
rock mechanics
geographic information system（GIS）
gypsum breccia
fracture appearance
geometrical properties
fractal
fractal dimension
