近距离上穿运营地铁隧道的基坑明挖施工控制技术

结合上海东西通道跨越地铁二号线工程研究了地铁上方基坑明挖的施工控制技术。研究提出了基于时空效应和充分利用隧道抗弯刚度的弹钢琴式开挖方法,采用SMW工法施工基坑围护墙和分隔墙将基坑分为若干个小基坑,小基坑采用跳仓和分层开挖方式。结合大面积搅拌桩地基加固以及地铁隧道的隔离桩和抗拔桩等工程措施,完成了大型基坑明挖施工中对下方运营地铁的保护。测试结果表明,地铁隧道的隆起量完全控制在安全范围之内。

Construction technology of deep open excavation above running metro tunnels

Critical construction techniques used in the deep excavation for West-East Transport System(WETS) are presented.Protecting the Shanghai Metro line 2 traverse by WETS in complex geological condition is of great concern.The construction scheme is established according to the principle of time-space effect and stiffness of tunnel.Deep soil mixing method is used to construct retaining walls which divide the excavation area into several little pits.Excavation sequence of the pits are jumping and single pit is ex...