The running tunnel of No. 16 Line of Shanghai Metro is a 10.4 mdiameter singletube shieldbored tunnel with separation wall. Separate design, i.e., some space being reserved between the top of the separation wall and the segment structure of the tunnel, should be adopted, so as to avoid the negative influence of the separation wall on the tunnel segment structure. In the paper, the deformation of the segment ring is calculated by means of elastic hinge ring method, elastic foundation beam method and continuous medium finite element method, considering tunnel segment dead load, ground load and ground consolidation settlement. Two cases, i.e., the rotation rigidity of the segment joints being 9 800 kN•m/rad and that being 19 600 kN•m/rad, are discussed. The calculation results show that the optimum space between the segment and the separation wall should be 10 cm to 15 cm.