岩石中锚杆拔出试验的数值模拟  

Numerical simulation of the pullout of anchor in rock

作　　者：杨强[1] 任继承[1] 张浩[1] 

机构地区：[1]清华大学水利系,北京100084

出　　处：《水利学报》2002年第12期68-73,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金资助项目(59879005)

摘　　要：采用二维格构模型分析了岩石中锚杆拔出试验。格构模型将材料在细观尺度上离散为由梁单元组成的格构系统。单元采用简单的本构关系和破坏准则,假定单元的抗拉强度服从正态分布,以引入岩石的非均质性。在外载作用下对整体网格进行线弹性分析,计算出格构中各单元的局部应力,超过断裂阈值的单元将破坏,材料的开裂过程通过单元的依次破坏来模拟。研究中考察了材料非均质程度、约束条件对开裂机理的影响。数值结果表明,非均匀性导致了开裂形态的非对称性,而增加水平约束后,试件的荷载-位移反应由脆性变为柔性。The pullout behavior of steel anchor embedded in rock is analyzed using lattice model.In the model the continuum is regarded as a connected lattice with elasticbristle beam elements.Fracture is simulated by performing a linear elastic analysis of the lattice under loading and removing an element from the lattice that exceeds a certain breaking threshold.The breaking threshold is chosen randomly from normal distribution to incorporate material heterogeneities.The influence of heterogeneity and boundary conditions on final cracking patterns and loaddisplacement curves are investigated.It is concluded that the crack patterns and associated loaddisplacement response are significantly governed by the heterogeneity,load patterns and boundary conditions.

关 键 词：岩石 锚杆 试验 数值模拟 格构模型 脆性材料 非均质 开裂 

分 类 号：TV223.1[水利工程—水工结构工程]