通过模拟计算大型泥水盾构2次穿越已建成地铁隧道过程，得出大直径隧道掘进施工时既有地铁隧道的纵向位移、抗浮及隧道衬砌结构影响数据，并通过计算分析结果提出减小对已建隧道影响程度的加固措施，以达到对地铁隧道的保护目的。

The influence of the boring of largediameter shield machines on the longitudinal displacement, antifloating performance and lining structure of the existing Metro running tunnel is obtained by means of simulation of the twice passing of the large slurry shield machines underneath the existing Metro running tunnel. Consolidation measures are proposed on basis of the calculation and analysis results to minimize the influence on the existing Metro running tunnel so as to protect the Metro running tunnel from being damaged.