关键词: 狭小空间, 大直径盾构, 异步协同调坡, 平移, 转体

Abstract: In the narrow working shaft space of overseas projects, problems always occur during the transition process of largediameter shield, including  tight construction schedule, lack of professional technical personnel, and largescale disassembly and assembly equipment. The construction technology of integral translation and Uturn of the largediameter shield in narrow space is studied by taking the tunnel under the Karnapuhli river in Bangladesh bored by a shield as an example. The results show that: by adopting a new type of steel ball base designed independently as the walking medium and supplemented by the laying of the bottom plate of the working shaft, the sliding friction between the steel sleeve integrated bracket and the bottom plate of the working well can be converted into rolling friction, greatly reducing the translation and rotation resistance. Furthermore, combined with the shield slope adjustment system design, the technology can achieve highprecision asynchronous coordinated slope adjustment, staged longdistance translation, and insitu 180° rotation of the largediameter shield in narrow working shaft space, providing reference and experience for similar projects in the future.

Key words: narrow space, large diameter shield, asynchronous cooperative slope adjustment, translation, rotation