基于统计概率分布的缺陷岩体建模与分析方法

Generation of Defects and Simulation of Damage Process in Rock Masses Based on Statistical Probability Distribution

依据岩石露头和岩芯采样获取岩体缺陷的统计信息,抽象出缺陷主轴长度、粒径、倾角等几何参数的概率分布特征.针对岩体中蕴含的颗粒、孔洞、裂隙、层理提出了缺陷的统一建模和自动生成方法,并开发了缺陷岩体参数化建模软件.结合有限元方法(FEM)和真实破坏分析方法(RFPA),对岩体的破裂行为进行了较为精细的分析计算.数值试验结果表明,即使是几何参数满足相同分布规律的正交节理岩体,其峰值强度最大相差15.7%,残余强度最大相差16.8%,依然表现出较高的随机性和离散性.有必要对多次生成的数字岩心重复压裂,用以获取宏观强度的分布区间.

Based on the statistical information of rock mass defects obtained from rock outcrops and rock cores, the probability distribution characteristics of the major axis length, grain size and dipping angle of rock mass defects are abstracted. A unified modelling and automatic generation method is proposed for defects with consideration of particles, pores, fissures and stratification in rock masses. A parameterized modelling program is developed for rock mass defects. Elaborate computation is per- formed for the fracturing behaviours of rock masses, by integrating the finite element method and the realistic failure process analysis （RFPA）. The numerical simulation results indicate that, even for the jointed rock mass with geometric parameters satisfying the same distribution law, its strength still ex- hibits a high degree of randomness and discreteness. The difference of ultimate strength is 15.7% and that of residual as to obtain the strength range of is 16.8%. Therefore, it is necessary to repeat uniaxial compression tests so macroscopic strength.