Study of Construction Method on Sole-Hole Double Deck Tunnel

2D elasto-plastic finite element method was adopted to analyze the forced state of the surrounding rock and the tunnel lining in every step of the construction project for Fulongping double-decked tunnel. In the analysis,Mohr-Coulombs yield criterion was employed incoporating associated flow law to account for the elasto-plastic characteristics of materials. The tangent stiffness method was adopted to solve the equation of equilibrium, and the stresses which exceeded yielded point were adjusted.