盾构隧道上浮的力学机理研究

已有工程监测资料充分反映了盾构法隧道、尤以大直径的盾构法隧道,在施工完成后的相当长时间内,均会产生上浮。本文将从隧道施工过程中,初始地层应力状态被破坏、洞周应力被部分释放、形成＂下大上小的不均匀＂应力状态着手,研究隧道衬砌（其重量远小于被开挖土体重量）上浮的必然性和力学机理。

Mechanical Mechanism Study of Shield Tunnel Floating Up

The collected existing monitoring data of shield tunnels illustrate that shield tunnels,especially those with large diameter would float up in a long period after construction.In this paper,it studies the inevitability and mechanical mechanism of floating up of tunnel(its weight is far less than the excavated soil’s) with the recognition that the initial stress state of soil layer is broken during tunnel shield driving and the stress around tunnel is partly released so as to form a kind of "unbalanced"(the upper stress is less than lower stress) stress state.