岩体节理产状极点分布的分形维

40多年来人们一直关注岩体节理产状分布的研究,但由于岩体节理产状呈现出双变量参数的复杂分布,因此准确地描述节理产状的特征及在实际岩石工程中的应用都很不成熟。据此,采用传统的下半球Schmidt等面积投影网与分形几何知识及计算机编程技能结合的方法,研究岩体节理产状空间分布的几何特征,给出岩体节理极点在下半球Schmidt等面积投影网中的分形维,总结出岩体节理极点分形维分布的基本规律,即节理极点较多的优势组其分形维值一般也较高。但节理极点产状的分形维还与该组节理产状分布的范围有关,产状分布范围越大,分散性越高,其所对应的分形维也越高。提出了节理产状在分布上存在分散度的概念,认为岩体节理极点分布分形维可表示与产状分布分散度的特征,并通过一个实例来讨论和分析上述研究成果。

FRACTAL DIMENSION OF ORIENTATION POLE DISTRIBUTION FOR ROCK MASS JOINTS

Orientation distribution of rock mass joints has been studied by scholars for about four decades,but the features of joint orientation distribution are still not easy to be described,because the orientation is distributed in the bivariate manner;and it is difficult to be used in the rock engineering.The method to combine the idea of box-counting method by Benoit Mandelbrot with the skill of lower hemisphere Schmidt equal area polar plot and the dynamic box-counting method by a computer program is employed to study the features of joint orientation distribution for each cluster.Then the fractal dimension of discontinuities pole on the lower hemisphere Schmidt equal area polar plot is calculated;and the basic regulations of orientation distribution and the relation between the fractal dimension and orientation dispersivity are put forward.The basic regulations of the fractal dimension of the joint orientation pole are that the more poles of the orientation clusters are,the higher value of the fractal dimension is.However,the results are not always the cases;and the fractal dimension values will be different when the values of the orientation ranges are different,even for the same amounts of poles of the cluster orientation.It shows that the higher fractal dimension of the orientation cluster is,the wider range of the orientation value for the cluster is,i.e.the more dispersivity is shown for the cluster orientation.