Abstract:Forked line 2# of Da—Ke running tunnel of Shenzhen metro is a complicated multi-tunneling system,with bad geological condition and strict envirionment restriction around it. In this paper,the optimized analysis on construction is done and complex 3D FEM model is set up. The ground subsidence and stability of surrounding rocks during construction are analyzed with 3D elasto-plastic FEM. From FEM computation,the maximum ground subsidence is less than 30 mm during excavation,and the failure zones of surrounding rocks and internal forces and deformation of tunnel support are also analyzed in detail. The analysis results have been proved by the real engineering that has been very successfully built.