- 责任者：Wang Xuebin (Department of Mechanics and Engineering Sciences ; Liaoning Technical University ; Fuxin 123000 ; China) ; Pan Yishan
- 刊名：The Chinese Journal of Geological Hazard and Control
- 出版年：2009
- 卷期：20(4)
- 关键词：隧道 ; tunnels ; 剪应变 ; shear strain
- 页码：p.101-108
- 图表：2 illus., 19 refs.
- 分类号：1702
- issnNo：ISSN1003-8035
- isbnNo：CN11-2825/P
///Shear strain localization processes of two circular tunnels with different diameters are modeled by use of FLAC. To model excavation, a FISH function is written and used to delete elements in tunnels. Rock elements exhibit linear strainsoftening behavior beyond the occurrence of failure and then the ideal plastic behavior. A composite Mohr-Coulomb criterion with tension cut-off is used. The present calculation is divided into three steps. Firstly, a hydrostatic pressure is applied to the plane strain model until a static equilibrium state is reached. Secondly, a tunnel is excavated using the written FISH function. Thirdly, the calculation renews to achieve a new equilibrium state for the small tunnel or a plastic flow state for the big tunnel. Results show that dog-ear or V-shaped notches are generated in the vicinity of the small hole and finally the surrounding rock reaches an equilibrium state. The result is consistent with the experimental result by Lu and Wang (1994) and many observations in situ.