高水位条件下盾构隧道开挖面稳定性数值模拟

Numerical Simulation for Stability of Excavated Surface of Shield Tunnels under Water Level Condition

通过考虑渗流影响的三维有限元数值模拟,对高水压条件下盾构隧道开挖面稳定性进行研究,获得开挖面破坏模式和极限支护压力。研究结果表明:开挖面前方土体破坏面倾角随水位增高而逐趋平缓,总极限支护压力与水位高度呈非线性关系,且其斜率随水位增高而增大;在水位高度一定时,隧道埋深越小,渗流力对开挖面破坏模式和极限支护压力的影响越大。

In consideration of 3D finite element numerical simulation for seepage effects, this paper studies the stability of excavated surface of shielded tunnels under the condition of high water pressure to obtain failure modes of excavated surface and limit support pressure. The results of study show that the angle of inclination failure surface of soil mass in front of the excavated surface gradually is intended to flatten with increase of water level, overall limit support pressure has a non-linear relationship with height of water level, and its slope increases with water level ; at the fixed height of water level, the less the burial depth of tunnels, the more influences of seepage force on failure modes of the excavated surface and limit support.