Rheological properties of different stress levels in deep slate of high-speed railway tunnel

Cui Jiachong tunnel of Shanghai-Kunming high-speed railway in Zhijiang County of Huaihua was selected as the engineering background. Six groups of samples in deep slate were collected at the construction site of tunnel. By uniaxial creep tests under different stress conditions, we obtained six groups of rock rheological properties of axial strain with time. The experimental results showed that: the stress value of 18.37 MPa was the boundary in these six groups of rock samples. In the stress state of less than 18.37 MPa, the rheological properties of slate were linear viscoelastic. When in higher stress state of higher than 18.37 MPa, it was nonlinear viscoelastic plastic. On the basis of match analysis in this paper, we introduced the Burgers' rheological model and nonlinear viscoelastic plastic rheological model (VEPB) to further verify the rheological properties of slate with the use of numerical simulation. In this paper, the research results indicate that: in the design of high-speed railway tunnel, a detailed analysis should be based on the rheological properties of rock under different stress conditions in order to calculate and optimize the structure parameters of tunnel lining. The research conclusions can provide certain theoretical and practical guidance for the support design of high-speed railway tunnel. © 2014 ejge.