浅覆土大直径盾构穿越对河堤影响的有限元分析
Finite element analysis of impact of under-crossing of large shallow shield tunnel on riverbank
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摘要: 以江阴澄江西路隧道工程为背景,采用基于地层损失率的位移控制有限元法(DCM),在自编Gleaves有限元软件中建立了DCM子程序,分析了浅覆土大直径盾构隧道开挖对河堤的影响。分析结果表明,浅覆土条件下,不同地层损失率对河堤沉降影响区别很大;为了保证河堤安全,地层损失率应控制在1%以内;通过现场监测结果对比发现,河堤最大沉降量为12 mm,地层损失率完全控制在1%以内,达到了很好的控制效果,保证了河堤的安全。Abstract: Based on the tunnel project of Jiangyin West Chengjiang Road, the impact of undercrossing of large shallow shield tunnel on the riverbank is analyzed by using the Gleaves finite element software. The subroutine of displacement control of finite element method (DCM) is established in the software based on the ground loss ratio. The analysis results show that the settlement of riverbank varies largely with different ground loss ratios under small overburden. The ground loss ratio should be controlled within 1% for the safety of the riverbank. The in-situ monitoring results show that the largest settlement of riverbank is 12 mm after crossing of shield tunnel. Good control effect is achieved and the safety of the riverbank is ensured .