岩体裂隙多边形模拟算法研究

Study on the Simulation of Rock Fractures by Polygons

确定岩体内部裂隙面的几何特征是岩体力学的基本问题之一,不同于传统的裂隙圆盘模拟方法,本文采用多边形来模拟岩体裂隙面,首先对采用多边形模拟岩体裂隙面的形状、大小、位置和方向等几何特征进行深入的分析,然后运用空间坐标变换的方法,经过两次旋转变换和一次平移变换,把一个大小确定、方向水平,四条边分别平行于总体坐标系两个水平坐标轴的正方形,变换到岩体裂隙面的实际位置和方向,如果再加上结构面之间的距离因素,即可实现成组发育、具有一定统计分布特征的岩体裂隙面的计算机模拟,工程实例表明,采用多边形模拟岩体的裂隙面的算法效率较高,而且还为以后的岩石块体切割算法以及图形系统显示算法的数据结构奠定良好的基础。

Determination of the geometric characteristics of fractures inside the rock mass is one of the basic questions in rock mechanics. Different from the traditional simulation method by joint discs,the joint polygons are proposed. Firstly,Polygons are adopted to analyze the shape,size,location and orientation of rock fractures. After that,transformations of the space coordinates are conducted including two times of a rotation and one translation.Therefore,for a known square,the size is determined,and the direction is assumed to be horizontal. Four edges of the square is parallel to the X axis and Y axis of the global coordinate system. Thereafter,the square can be transformed to the actual location and real direction of the rock fractures with the above method. If the spacing of the joints is considered,simulation of the joint sets with different statistical distributions can be realized. The engineering examples show that,the efficiency of the algorithm with joint polygons is higher than the one of joint discs. This will lay a solid foundation for the further study on the algorithms of block cutting and displaying later.