Stability Analysis of Tunnel Surrounding Rock and Shotcrete Lining and Rock Bolts Based on Strength Reduction Finite Element Method

Based on the practical engineering ,by using the 3D-FEM of elastic-plasticity, a reasonable model for simulation of tunnel excavation and shotcrete lining and rock bolts builds up, surrounding rock using Mohr-Coulomb constitutive model of ABAQUS, lining using Concrete Damaged Plasticity constitutive model, and bolt using elastic-plasticity constitutive model. By using strength reduction finite element method, analysis for safety coefficient of stability of surrounding rock with primary shotcrete lining and rock bolts under the four limit state criteria. It is concluded that the appearance of divergence of the computation may precede by displacement of characteristic points, The safety coefficient of the running-through of the plastic zone of the surrounding rock and the running-through of the plastic zone of the shotcrete and a great amount of rock bolts yielding are less than the divergence of the computation and displacement of characteristic points.