以南京地铁3、10号线过长江隧道为背景，针对其距离长、风险高、施工难度大等特点，在国内地铁行业首次提出采用单洞双线大直径盾构隧道的断面形式。分别从设计与施工难点及采取的措施出发，通过工程类比、仿真计算、现场试验等研究手段，确立了11.2 m外径的单管双线三层内部结构的地铁过江大直径盾构隧道横断面，解决了地铁大直径盾构隧道衬砌环分块形式，提出了利用隧道顶部富裕空间的纵向通风模式。实践证明，在直径为10～12 m类大直径盾构隧道的常压换刀的应用中是可行的、安全的。研究成果可为城市大断面越江地铁盾构隧道工程提供借鉴。

The scheme of largediameter shield tunnel, which is characterized by singletube doubleline, was proposed for the construction of Yangtze Rivercrossing tunnels on Line No. 3 and Line No. 10 of Nanjing Metro for the first time in China. The design, construction and related countermeasures during tunneling of Nanjing Metro are proposed. The horizontal crosssection of largediameter rivercrossing shield tunnel constitutes a singletube with doubleline, which is a triplefloor structure. The circular lining ring of largediameter shield tunnel is accordingly proposed, and the longitudinal ventilation is set in the top margin space of tunnel crosssection. The construction practices illustrate that the drill bit replacement under the atmospheric condition is suitable for largediameter shield tunnel (diameter 10～12 m). The experiences accumulated in this project can provide reference for similar rivercrossing Metro shield tunnels with largediameter in the future.