模拟岩体失效全过程的连续-非连续变形体离散元方法及应用

CONTINUOUS-DISCONTINUOUS DEFORMABLE DISCRETE ELEMENT METHOD TO SIMULATE THE WHOLE FAILURE PROCESS OF ROCK MASSES AND APPLICATION

岩石、混凝土等材料,由于存在细观构造的非均匀性,其损伤-破碎发展过程及破损特征与材料中含有的微裂隙分布相关。基于有限-离散耦合分析的思路,在变形体离散元法的基础上引入基于弹塑性断裂力学的黏聚力模型,在细观单元之间插入界面单元,并对界面单元的刚度等参数进行推导,通过界面单元的起裂、扩展和失效,实现岩体开裂扩展的数值模拟。以岩石单轴压缩、单个颗粒破碎以及边坡失稳3个算例对该方法进行验证,结果表明:所提出的方法能较好地模拟计算裂纹的开裂萌生与扩展,反映岩石介质从小变形到大变形再到破坏的全过程。

Rocks,concrete and other materials,due to the existence of inhomogeneity of mesoscopic structure,their fracture-broken development process and damage characteristics are associated with the distribution of micro cracks contained in the materials.Based on the idea of finite-discrete coupling analysis,a cohesive zone model based on elastoplastic fracture mechanics is employed to simulate the fracture of rock.In this model,the cohesive interface elements are inserted into the region of coarse aggregates and the parameters such as stiffness of the interface are deduced.If the interface cracks and failures,fracture will happen.Using uniaxial compression,a single particle breakage and slope instability simulation,the method is verified.The results show that this method can simulate the crack initiation and propagation effectively and reflect the whole process from small deformation to large deformation and failure.