粉细砂地层盾构施工风险分析与应对措施

通过南京地铁河西粉细砂地层盾构施工实例，针对粉细砂地层盾构施工难点，分析施工过程中存在的主要风险，并根据风险的发生条件、施工中防止隐患或处理隐患的方法，归纳施工应对措施，特别是对该地层施工中可能遇到的涌水、涌砂及地表沉降失控、建构筑物变形过大等施工风险进行总结分析,最终有效地控制了险情，避免了许多施工风险，特别是在盾构穿越无基础砖切厂房所采取的应对技术措施对类似地层的风险控制及应对有一定的参考作用。

Analysis and Countermeasures for Risks in Shield Boring in Fine Silty Sand Ground

Taking the shield boring of Nanjing Metro in fine silty sand ground as an example, the author analyzes the main risks in tunnel boring and summarizes the construction countermeasures, particularly in aspect of water inflow, sand inflow, ground surface settlement and building/structure deformation. In the end, the risks have been brought under effective control. The countermeasures presented in the paper, especially those for shield boring under brick masonry workshops without foundations, can provide reference for similar projects in the future.