基于单元劈裂法的岩体黏结型结构面数值模拟  

Numerical simulation of cohesive discontinuities in jointed rockmass based on element partition method

作　　者：陈亚雄[1] 张振南[1] 

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《岩土力学》2013年第S2期443-447,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金资助(No.11172172);国家重点基础研究发展计划(973)项目资助(No.2011CB013505)

摘　　要：节理岩体中富含结构面等不连续体,其中很多结构面之间具有一定黏结强度,在冲击荷载作用下会发生脱结(debond)行为,从而消耗岩体应变能。在该结构面之间的黏结性质在很大程度上决定着岩体的破坏行为,发生脱结后,结构面之间不再具有黏结强度,岩体的力学性能发生弱化。为了对该类结构面进行模拟,在改进的Xu-Needleman势函数基础上推导出结构面单元,并将其嵌入到单元劈裂法中,模拟结构面的开裂过程,当结构面完全脱结后结构面单元就转化为一般节理单元。相应地,在数值实现过程中只是将结构面单元替换为一般节理单元即可。该结构面单元与单元劈裂法相结合,能够有效地模拟节理岩体的破坏过程。Jointed rockmass contains numerous discontinuities. Many of them are not distinctly separated and have certain cohesive strength. The bonded interfaces enable the jointed rockmass to have a high strength. When subjected to the dynamic load, these discontinuities will debond, dissipating the strain energy accumulated in rockmass. The cohesive properties of the discontinuities govern the fracture energy of rockmass to great extent. The debonded interfaces significantly weaken the rockmass. The improved Xu-Needleman potential function can well describe the cohesive properties of cohesive discontinuities. Based on the improved Xu-Needleman potential function, the paper derives the cohesive discontinuities element. To simulate the cohesive discontinuities in a jointed rockmass, the cohesive discontinuity element is embedded into the element partition method, which allows an intact element to accommodate a discontinuity without introduction of external degrees of freedom. When the cohesive discontinuity element is identified to debond;it will be automatically replaced by a usual joint element to reflect the contact and the friction effect between the debonded discontinuities. The simulation example suggests the discontinuity element in conjunction with the element partition method is an efficient method to simulate the discontinuity debond and growth in the jointed rockmass. The perspective of the present method should be highly inspiring in simulating the failure behaviors of the jointed rockmass subjected to dynamic load.

关 键 词：黏结型结构面 节理岩体 界面单元 单元劈裂法 数值模拟 

分 类 号：TU452[建筑科学—岩土工程]