Abstract The deformation and failure events that occurred in the Tongsheng tunnel resulted in longitudinal crack? ing in the crown and steel arch breaking at the spandrel. Considering the anisotropic characteristics of the Wudang group schist, the characteristics of the stress-strain curve and the failure pattern of samples of the Wudang group schist are analyzed based on the surrounding rock deformation properties, the numerical simulation, the wave velocity test, the uniaxial compression test and the triaxial compression test. A corresponding relationship between the elastic modulus, Poisson′s ratio and compressive strength versus the schistosity angle changing from 0° to 45° and 90° is established, the failure mode of the tunnel surrounding rock is presented and the deformation mechanism of the tunnel′s surrounding rock is summarized. The results show that the anisotropy of the Wudang group schist plays a controlling role in the process of deformation and failure of the tunnel′s surrounding rock; the asymmetric mode is the main failure mode of the tunnel′s surrounding rock; and when the spatial relationship between the maximum shear stress of the tunnel′ s surrounding rock and the schistosity is unfavorable, the surrounding rock will shear along the schistosity plane.
Abstract:
The deformation and failure events that occurred in the Tongsheng tunnel resulted in longitudinal crack? ing in the crown and steel arch breaking at the spandrel. Considering the anisotropic characteristics of the Wudang group schist, the characteristics of the stress-strain curve and the failure pattern of samples of the Wudang group schist are analyzed based on the surrounding rock deformation properties, the numerical simulation, the wave velocity test, the uniaxial compression test and the triaxial compression test. A corresponding relationship between the elastic modulus, Poisson′s ratio and compressive strength versus the schistosity angle changing from 0° to 45° and 90° is established, the failure mode of the tunnel surrounding rock is presented and the deformation mechanism of the tunnel′s surrounding rock is summarized. The results show that the anisotropy of the Wudang group schist plays a controlling role in the process of deformation and failure of the tunnel′s surrounding rock; the asymmetric mode is the main failure mode of the tunnel′s surrounding rock; and when the spatial relationship between the maximum shear stress of the tunnel′ s surrounding rock and the schistosity is unfavorable, the surrounding rock will shear along the schistosity plane.
.Deformation Mechanism of Tunnel Surrounding Rock Based on an Anisotropic Test of the Wudang Group Schist[J] MODERN TUNNELLING TECHNOLOGY, 2017,V54(5): 155-163