超大直径土压平衡盾构针对性设计及风险应对措施

Targeted Design and Risk Response of Super Large Diameter Earth Pressure Balance Shield Tunneling

针对超大直径土压平衡盾构在风化泥岩夹砂岩、圆砾土段和上软下硬地层施工难题,依托成渝中线蜀安隧道1标段工程,通过现场地质资料分析、工程类比以及专家研讨,总结归纳工程施工重难点,包括浅覆土超大直径管片上浮控制、隧道近接既有高风险源施工、大直径盾构刀盘结泥饼、长距离掘进刀具管理、盾构隧道穿越微瓦斯段地层等。依据研究结果分析复杂地层条件下超大直径土压平衡盾构选型并提出优化设计方案及风险控制措施,对超大直径盾构优化设计及施工具有重要参考价值和指导意义。

In response to the problem of crossing weathered mudstone with sandstone,round gravel soil section,and upper soft and lower hard strata with a super large diameter earth pressure balance shield,relying on the Chengdu Chongqing Middle Line Shu’an Tunnel Section 1 project,by analyzing on-site geological data,engineering analogies and expert discussions,the key and difficult points of engineering construction are summarized,including floating control of super large diameter pipe segments with shallow soil cover,construction of tunnels adjacent to existing high-risk sources,large diameter shield tunneling cutter coiled mud cake,long distance excavation tool management,shield tunneling passes through micro gas section strata,etc.Based on the research results,the selection of super large diameter earth pressure balance shield tunneling under complex geological conditions is analyzed,and the optimization design plans and risk control measures are proposed,which has guiding significance for the optimization design and construction of ultra large diameter shield tunneling.