双重孔隙-裂隙岩体中地下洞室稳定性的瞬弹-粘弹-粘塑性二维有限元分析  

2D transient elastic-viscoelastic-viscoplastic FEM analyses for stability of underground cavern located in dual-pore-fracture rock mass

作　　者：张玉军[1] 琚晓冬[2] 

机构地区：[1]中国科学院武汉岩土力学研究所,岩土力学与工程国家重点实验室,武汉430071 [2]河南理工大学土木工程学院,焦作454000

出　　处：《中国科学：技术科学》2016年第3期276-285,共10页Scientia Sinica(Technologica)

基　　金：国家自然科学基金(批准号:51379201);国家重点基础研究发展计划(批准号:2010CB732101)资助项目

摘　　要：用西原模型描述双重孔隙-裂隙介质的流变特性,但其中的瞬弹、粘弹及粘塑性元件由岩块和节理的成分构成,建立了该模型的平面有限元求解格式并引入已开发的计算程序中.针对一个矩形地下洞室围岩中无、有成组正交或斜交裂隙的四种计算方案,进行数值模拟,分析、对比了围岩中的位移、应力及塑性区.其结果显示:多组裂隙的作用一是降低了完整岩体的抗剪强度,二是改变了围岩中的应力分布及量值;与单一介质相比,双重介质围岩中位移的方向有所变化,其随时间发展的量值明显增大,并且应力场的分布也有相应的改观;随裂隙组倾角的改变,双重介质围岩中的塑性区范围可能比单一介质围岩中的大或小.The rheological characteristics of dual-pore-fracture media are described by using Nishihara model, but the transient elastic, viscoelastic and viscoplastic elements of the model are composed of rock blocks and joint components, so the relative solving format of plane finite element method is established and introduced into the computation code developed by the authors. Aiming at the four conditions of surrounding rock mass of a rectangular underground cavern, in which the first rock mass is a whole（single medium） and the latter three are fractured by two sets of joints with different intersection angles（dual media）, the numerical simulations are carried out, and the displacements, stresses and plastic zones in the surrounding rock masses are analyzed. The results show that the effects of multiple fracture sets may reduce the shear strength of intact rock mass, and change the distributions and values of stresses in the surrounding rock mass. Compared with the case of a single medium, the displacement directions of the surrounding rock mass of dual medium vary, the displacement values developing with time increase obviously, and there are also corresponding changes for the distributions of relative stress fields. With changes of the dip angles of fracture sets, the plastic zones in the surrounding rock mass of dual medium may be larger or smaller than that in the surrounding rock mass of single medium.

关 键 词：双重孔隙-裂隙岩体 瞬弹-粘弹-粘塑性模型 地下洞室 稳定性分析 有限元方法 

分 类 号：TU45[建筑科学—岩土工程]