3D numerical simulation on double-arch tunnel's construction process

With three-dimensional model, this paper simulates the spatial effect of double-arch tunnel's construction, analyzes the transaction between the left tunnel and the right tunnel, and studies the deformation and stability of mid-partition. The region of the left tunnel affected by the excavation of the right tunnel is 3 B (B is the excavation span of right tunnel, B = 12 m) in front of and at the back of excavating face. During the construction of the right tunnel, the mid-partition behind the excavating face deflects to the left as a whole, the middle part of the mid-partition bulges to the left and the right toe rises. The backfill on the left of mid-partition prevents it from deforming effectively, so the quality of it should be guaranteed during construction process. Distance between the two excavating faces should be less than 2.5 B - 3.0 B to control the deformation of mid-partition.