盾构隧道下穿含气地层江堤沉降控制分析

Analysis on Bank Settling Control of Shield Tunnel Passing under Gas Formations

针对杭州地铁某盾构隧道下穿富含沼气地层的防洪大堤工程,数值模拟分析盾构下穿防洪大堤过程中引起的大堤沉降和分层注浆加固对沼气释放引起的大堤沉降控制效果,借此提出合理的大堤沉降综合控制措施。研究表明,分层注浆加固对控制大堤沉降效果明显,最大沉降值减小幅度达31.9%;沼气释放对大堤的沉降影响较大,需要在推进过程中严格控制盾构土仓压力和推进速度。

For the project of Hangzhou metro shield tunnel passing under bank with layers rich in methane, the numerical simulation analysis shows that bank settlement is caused during shield tunnel passing under embankment and layered grouting and enforcement, having the control effect of bank subsidence caused by methane release. Therefore reasonable comprehensive measures are put forward. The study shows that effect of layered grouting for control bank settlement is obvious, the reduce of maximum settlement value is by 29%, Release of methane has a very big impact on settlement so it is very important to strictly control soil presstire and shield advance speed.