Three-Dimensional Face Stability Assessments of Seismic Tunnels in Weak Rock Masses

다국어 초록 (Multilingual Abstract)

The face stability assessments of seismic tunnels have been complicated and crucial problems. To solve this issue, an advanced three-dimensional (3D) rotational failure mechanism with considering seismic effects is developed to assess the seismic face stability of shield tunnels in weak rock masses. The Hoek-Brown (HB) failure criteria is employed to characterize rock masses with weak strength. The corresponding Mohr-Coulomb (MC) parameters are determined using the tangential line method. The modified pseudo-dynamic (MPD) approach is utilized to accurately involve damping property of geomaterials, realistic surface boundary conditions and dynamic properties of seismic waves in face stability assessments. The upper limit analysis approach is utilized for the determination of critical face pressures of seismic tunnels. Comparisons against numerical and analytical solutions demonstrate the efficacy of proposed approach for evaluating the seismic face stability. Subsequently, the impacts of seismic actions and weak rock parameters on face stability are analyzed and a design table is provided for practical use. Finally, the proposed approach is tested by conducting seismic face stability assessments of the JinXiu tunnel with actual seismic response.