上跨地铁隧道深基坑开挖控制措施及实测分析

Excavation control measures and measurement analysis of deep foundation pit above metro tunnel

依托郑州市某道路快速化改造工程,采用数值模拟方法研究了深基坑开挖对下方运营地铁盾构隧道的影响,结果表明,基坑分隔墙能有效减小两侧基坑开挖对地铁的影响,单次开挖卸载量与地铁隧道上浮量正相关,通过将上跨地铁深基坑化大为小,并合理设置基坑开挖顺序,结合“门”式地基加固等措施,可以有效控制地铁隧道的上浮,保证地铁运营安全。经与现场实测数据对比分析,验证了数值模拟结果的可靠性,说明设计方案所采取的工程措施是合理有效的,供类似工程参考。

Based on a rapid transformation project in Zhengzhou,the numerical simulation method was used to study the impact of deep excavation on the operating metro shield tunnel below.The results showed that the partition walls of the foundation pit can effectively reduce the impact of adjacent excavation on the metro tunnel.The unloading volume of a single excavation is positively correlated with the floating amount of the metro tunnel.By minimizing the size of the deep foundation pit crossing the metro tunnel and reasonably setting the excavation sequence,combined with portal-type foundation reinforcement,the floating of the metro tunnel can be effectively controlled to ensure the safe operation of the metro.By comparing the simulation results with the field measured data,the reliability of the numerical simulation was verified.It also proved that the engineering measures adopted in the design scheme are reasonable and effective,and can serve as a reference for similar projects.