Study on Damage of Jointed Rock Tunnel by Stochastic Fractures

Based on damage mechanics, rock mechanics and finite element method, finite element program of damage additional displacement is compiled. A set of stochastic fractures is chosen, its dip is NW30°. The damage effect of jointed rock tunnel is discussion under different dip angle, density (damage factor) and filling condition (tension & pressure shear stress transfer coefficient). The analysis shows that damage additional displacement absolute value of tunnel vault and bottom increase with damage factor increasing. And their relationship is nonlinear. The tunnel damage effect is unrelated with tension shear stress transfer coefficient when dip angel of stochastic is 0° and 90°. Damage effect of key point on vault and bottom is basically contrary under the same dip angel. The smaller is dip angel, the greater is damage effect of vault settlement and bottom hump. The damage effect of tension shear stress transfer coefficient is larger than that of pressure shear stress transfer coefficient. But the damage effect of variation of tension shear stress transfer coefficient is less than that of pressure shear stress transfer coefficient.