用非连续变形分析方法模拟岩石裂纹扩展

SIMULATION OF ROCK CRACK PROPAGATION USING DISCONTINUOUS DEFORMATION ANALYSIS METHOD

提出一种用非连续变形分析方法模拟岩石裂纹扩展的方法。将计算区域自动剖分成三角形块体单元,块体边界分为真实的节理边界和虚拟节理边界。裂纹扩展沿虚拟节理进行,按照界面破裂准则进行裂纹扩展分析。该方法可以模拟裂纹萌生、扩展、贯通和岩体破碎全过程,适用于完整岩石、断续岩体乃至完全不连续岩体等任意情形。由于该方法基于离散颗粒数值模型,其计算过程不会遇到数学上的困难。根据所提算法,编制VC++程序模块,并计算几个算例。模拟结果与已有的物理、数值试验结果吻合得较好,表明所提算法是有效的。

An approach for modeling rock crack propagation using discontinuous deformation analysis（DDA） method is presented.In the proposed approach,the triangular block system is automatically generated in the area of interest by adopting the advanced front method.During this process,numerous artificial joint interfaces,compared to real joint interfaces,come into being.These artificial joint interfaces provide the paths along where cracks generate and propagate.The strength of the artificial joint takes the same value as that of the intact rock;and the failure of the artificial joint is controlled by the maximum tensile-stress criterion and Mohr-Coulomb criterion.In this wayt,he proposed method can easily simulate the generation,propagation and coalescence of rock crack;the whole process of rock fragmentation is thereafter reproduced.Moreover,with the introduction of the artificial joint concept into the discontinuum-based modelt,he proposed approach can be used to simulate the cases of continuum,semicontiuum as well as discontinuum without any mathematic difficulty.Based on the proposed algorithm,the corresponding VC＋＋ program module is developed.For verification,several numerical examples are computed to study the propagation and coalescence of the closed joints in rock mass under uniaxial compression.The simulated results are compared with the existing physical and numerical test ones.They show a favorable agreement,and the laws of the crack propagation are in accordance with the phenomena observed in the tests.These indicate that the proposed method for crack propagation analysis is correct and effective.