摘要
自然形成的岩石节理面的表面形状具有分形特性,利用分形理论来描述岩石节理的粗糙特性,并确立与岩石节理面的剪切力学特性间的关系对于指导岩体工程设计、施工和管理具有重要意义。本研究利用开发设计的三维激光测距仪在精确测定岩石节理面的表面形状的基础上,依据变量图法建立了新的岩石节理面的分形几何模型,模型中的两个分形参数(振幅B和分形维数D)分别定量表述了岩石节理面表面形状的两个几何特性(一级倾斜度和高级次起伏度),在此基础上,进一步提出了由这两个分形参数组合得出的代表岩石节理面表面粗糙特性的平均粗糙角U的概念和计算方法。其次,在岩石节理面剪切强度实验基础上,应用新的分形模型,建立了剪切强度和分形参数及平均粗糙角U的定量关系。
There are the properties of fractals for the naturally developed rock fracture surfaces. It has important significance for guiding the design, construction and management of rock engineering to describe the roughness of rock discontinuous surfaces with fractal geometric theory and to understand the roughness of rock discontinuous surfaces in relation to the shear mechanical properties in loading. Based on the measurement of the fracture surfaces with three dimensional laser scanning instrument, the new fractal geometry model of rough fracture surfaces of rocks are developed and analyzed according to the variogram method. Trie geometric properties of rock fracture surfaces (the basic slope and high grading waviness) can be described quantitatively by the two fractal parameters (amplitude B and fractal dimension D) of the model separately. On the basis of this, the conception and calculated method of average roughness angle U(h) is put forward which represents the roughness property of rock discon-linuouns surfaces. The shear tests on rock discontinuous surfaces show a combined effect of the fractal parameters (average roughness angle U(h)) on the shear mechnical properties. The quantitative relation of shear strength and the fractal parameters (or average roughness angle U(h)) has been obtained based on the shear tests by using the new fractal model. Furthermore, the shear strength rock discon-imuous surfaces is predicted. The results show that the predicted values is in consonance with the tested values.
出处
《上海力学》
CSCD
1997年第1期10-21,共12页
Chinese Quarterly Mechanics
关键词
岩石节理
粗糙面
分形几何模型
剪切强度
natural rock joints, fractal geometry, roughness surfaces, average roughness angle, shear strength.
