Abstract:

It is of great importance to master the deformation rules of the surrounding rock mass during construction so as to control the large deformation occurring during the construction of tunnels located in high ground stress regions. Furthermore, mastering the deformation rules of the surrounding rock mass is also the technical basis for the selection of the excavation methods, reinforcement types, reinforcement parameters and reinforcement opportunity. In the paper, numerical analysis is made on the deformation rules of the surrounding rock mass occurring during the "top heading and bench" excavation of tunnels with high ground stress and large deformation by means of finite element numerical simulations. Investigation is also made on the influence of the core soil length on the deformation. Proper bench lengths and core soil lengths are proposed in the paper, which can provide guidance for the design and construction of tunnels with high ground stress and large deformation in the future.

Key words: high ground stress  large deformation numerical simulation “top heading and bench&rdquo, method