2D-FEM was applied to simulate and analyze several construction schemes, of which shield method was adopted in left tunnel with small inner section and double-heading construction method or cross diaphragm method for right tunnel with large inner section. The results show that compared with the construction scheme that the tunnel with small inner section is firstly excavated, the one that tunnel with large inner section is first accomplished can evidendy reduce the disturbance effect on surrounding rock, decrease the setdements of ground. Compared with CRD method, Double-heading construction method has advantages in utilizing the self-supporting ability of surrounding rock and supporting ability of preliminary lining, and also improving safety margin of the second lining.
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