中文摘要：

提出地质体渐进破坏的多尺度计算框架,确定不同尺度的计算条件和物理参数的选取方法。将工程地质模型分为3级尺度:(1)工程地质模型的实际尺度,从百米到千米量级;(2)满足计算精度的数学网格,即等应力应变单元的尺度,通常为米量级;(3)描述地质体破坏的特征尺度,可以选为实验室试样尺度,通常分米量级。在该多尺度计算框架下,地质体材料的破坏可以采用实验室测得强度参数进行描述。提出适用于多尺度计算的一种基于剪应变强度分布的新的强度准则,该准则以应变作为强度指标,定义剪应变强度在材料中服从某种分布,未达到强度部分保持线弹性,超过强度的部分用库仑摩擦描述。该强度准则可以表述材料的非线性屈服和软化现象,得到材料的渐进破坏过程。当应变强度区间变化时可以自然得到脆断模型、软化模型以及理想弹塑性模型。通过离散元的算例计算表明,该模型中将材料的内部细观状态表述为弹性微元面和破裂微元面,并用线弹性和库仑摩擦参数分别表达是合理的。

英文摘要：

Multiscale computational framework is proposed to describe progressive failure of geological body. Calculation condition and determination method of physical parameters in multiscale are established. Engineering geological model is divided into three computational scales,which include size of actual model from hundreds to thousands meters,size of mathematical mesh with meter scale and characteristic size of fracture corresponding to experimental sample scale. Strength parameters from lab can be used to describe failure in this multiscale computational framework. A new strength criterion based on distribution of shear strain strength on shear plane is introduced,in which strain is used as the strength index and shear strain strength complies with a certain distribution law. Area where shear strain is below the shear strain strength keeps linear elastic,while the rest turns into Coulomb′s friction. Nonlinear behavior of material such as yielding and strain softening can be described. Elasto-brittle model,strain softening model and ideal elasto-plastic model can be naturally obtained through the variation of the interval of upper limit and lower limit of strain strength. Numerical result of discrete element method shows that it is reasonable to describe the internal microscopic damage with elastic microplane and fracture microplane which are expressed with linear elastic and Coulomb′s friction parameters,respectively.