节理岩体宏观力学参数尺寸效应的数值试验

基于Mont-Carlo法，建立了节理岩体的结构面网络，采用RFPA2D-DIP数值模拟软件把生成的网络图转化为有限元网格，从而建立能反映材料细观结构的数值模型.对其中6个不同尺寸的节理岩体试件进行单轴受压数值模拟试验，分析了不同尺寸节理岩体应力与应变之间的关系，以及抗压强度和变形模量的尺寸效应，并对岩体的破坏过程进行了研究，描述了1500mm×1500mm岩体的破坏过程.结果表明，随着岩体尺寸的增大其抗压强度和变形模量均减小，但变化幅度却越来越小，抗压强度随尺寸增大趋于稳定的速度更快，并得出了指数衰减的拟合关系式，不同尺寸岩体的破坏过程大致相同.该研究方法为节理岩体宏观力学参数的研究提供了一种新方法.

Numerical Test on Size Effect of Macro-mechanical Parameters of Jointed Rockmass

Based on the Mont Carlo method， the structural plane network of jointed rockmass was generated， and it was used to build the finite element model of rockmass through numerical code RFPA2D DIP， where the microstructure of rockmass was considered. Numerical tests on six rockmass samples with different size of rocks were carried out under uniaxial compression loading， the stress strain relationship of jointed rockmass was studied， and the size effect of compressive strength and deformation modulus were analyzed. After the failure process of jointed rocks with different scale were examined， the failure process of 1500mm×1500mm rockmass was described. The results showed that compressive strength and deformation modulus declines with the increasing size of jointed rockmass， but the variable range became narow gradually， the compressive strength tends to stabilize faster with the increasing size， and the fitting relation about exponential decay was obtained. The failure processes of jointed rockmass with different scale was similar. The method can offer a new tool to research macro mechanical parameters of jointed rockmass.