Numerical Analysis of a Shallow-Buried Portal in Expressway Tunnel with Weak Rockmass

摘要: Aiming at the problems in construction for a shallow-buried and unsymmetrical loading portal Banzhulin Tunnel Yu-Xiang expressway, finite element simulation were carried on to study behavior bench excavation method. Main results of numerical analysis as follows:the displacement surrounding rock right tunnel(as AR)at horizontal direction is large may larger than that left AL) vertical direction,and largest deformation 22.63mm,occuring key point DL. Compared with data monitoring measurement, correctness this was proved.The stress mountain tunnels basically mastered,and rockmass factor tunnelling.