上海地铁9号线盾构上穿越已建隧道施工技术

Construction Technology of Shield Construction Up-crossing Built Tunnel in Shanghai Metro Line 9

上海地铁9号线西出入段盾构施工上穿越已建成的主线隧道,掘进时采用控制掘进速度、设置抗浮板、地基加固、已建隧道和地表堆载压重、设置预偏量、注浆加固等关键施工技术,成功解决了盾构近距离上穿越、小半径曲线推进、浅覆土推进等技术难题。隧道轴线偏差控制在±50mm以内,立交段最大隆起值在10mm以内,已建隧道最大隆起值在1.2mm以内,隧道收敛值-2.7-1.2mm,达到了工程技术要求,有效保护了已建隧道及周边环境安全。

West in-out segment in Shanghai Metro Line 9 up-cressing main line of built turn,el. Some key construction technologies are adopted during excavation, such as controlling driving speed of shield machine, designing anti-float plate, pre-loading on built tunnel and ground surface, setting pre-deflection as well as grouting to reinforce tunnel. Technique difficulties are solved by the technologies, such as shield up-crossing built tunnel closely, driving shield machine with small radius and curves as well as shallow buried soil. As a result, tunnel axis deflection is controlled in ± 50mm, the largest uplift at crossing section in 10mm and built tunnel in 1.2mm, and convergence value of tunnel in - 2.7 - 1.2mm. All the mentioned paraneters can match requirements of engineering and technology. Safety of built tunnel and surrounding environment is protected efficiently.