针对北京地下直径线大直径泥水盾构在施工过程中遇到的地质条件复杂、盾构独头长距离掘进、变形控制标准严格、多工法交接施工、施工场地狭小和环保要求高等重难点，从刀盘刀具与地质适应性、高压环境下盾构刀盘刀具检修、环保型泥水系统、城市核心区地表建筑物变形控制等方面介绍了泥水盾构施工关键技术。这些技术的研究及应用，表明气垫式泥水平衡盾构具有施工安全性高、富水地层适应性好、地层沉降小、可控且对环境影响小等特点，可以向全地层、大埋深、长距离、复杂环境条件推广应用。

Based on the research of large diameter slurry shield tunneling practice in Beijing railway underground diameter line project, this paper analyses and summarizes the key technologies of slurry shield tunneling, including cutting tools and geological adaptability of cutting tools, maintenance and repair of cutter head under hyperbaric condition, environmental protection of slurry treatment system, control of settlement of buildings and environmental impact in CBD, etc. The research and application of above technologies demonstrate that air cushion slurry shields have such advantages as high safety, good adaptability to water rich strata, small ground subsidence, controllable ground subsidence and low impact on the environment, etc. and that they can be used in long deep tunnels in complex geological conditions. 