换乘通道上跨地铁隧道受力分析及技术措施

THE STRESS ANALYSIS AND TECHNICAL MEASURES THAT THE UNDERGROUND TRANSFER LINE CROSSING OPERATED THE SHIELD TUNNEL

为了使得明挖换乘通道上跨已运营地铁隧道设计方案达到安全可靠,本文采用有限差分数值分析法对此进行了模拟分析。结果表明,在已建隧道近距离卸载,会引起下方盾构隧道周围土体产生应力重分布及竖向变形(隆起),当基坑开挖至设计标高底面时,隧道的竖向变形达到最大,最大值为约15.7mm,不满足规范要求;有限差分数值分析结果表明设计中应采取措施减小竖向位移,结合既有工程经验,本文介绍了明挖换乘通道上跨已运营地铁区间隧道的技术措施,以供类似明挖通道上跨已运营地铁隧道处理措施参考。

In order to make the design scheme of underground subway tunnel to operate safely and reliably, the finite difference numerical analysis method is used to simulate this project. The results show that the excavation unloading will cause stress redistribution and vertical deformation of the surrounding soils of the existed shield tunnel. Furthermore, when the foundation pit was excavated to the bottom,the vertical deformation of the tunnel is biggest. The maximum value is about 157 mm,which did not satisfice the specification requirements; technical measures should be taken to reduce the vertical deformation in the design. Take the existed engineering experience for reference. This article introduces the technical measures for tunneling across the already operated metro tunnels on the open cut interchange channel for reference to the handling measures for cross-operated subway tunnels on similar open-cut tunnels.