考虑渗流的盾构隧道开挖面稳定性分析  

Stability analysis of shield tunnel excavation face with the consideration of seepage

作　　者：乔金丽[1] 张义同[1] 许春彦[1] 

机构地区：[1]天津大学机械工程学院,天津300072

出　　处：《水文地质工程地质》2009年第1期80-85,共6页Hydrogeology & Engineering Geology

基　　金：国家重点基础研究发展计划(973计划)(2007CB714001)

摘　　要：通过工程实例,应用VB6.0与FLAC3D软件集成可视化系统,考虑水的渗流效应和不考虑水的渗流效应两种情况,对盾构隧道开挖面的稳定性进行分析。根据稳定性理论,确定开挖面支护压力在进行微小变化时,中心点水平位移发生突变时的支护压力为极限支护压力,得到了两种情况下开挖面的极限支护压力、应力场、位移场和塑性区的变化。结果表明:开挖面失稳的极限支护压力等于作用于开挖面有效支护压力和渗透力的总和,考虑渗流的开挖面极限支护压力大于不考虑渗流的极限支护压力,渗流力构成了总支护力的主要部分;由于孔隙水压力的影响,考虑渗流效应的隧道开挖面应力小于不考虑渗流效应时的应力,其位移和塑性区却大于不考虑渗流作用的位移和塑性区;考虑渗流情况下开挖面的稳定性比不考虑渗流情况要差。同时与实测资料比较,验证了软件系统的合理和有效性,为设计和施工时开挖面支护压力的施加提供了一定的指导依据。Through engineering example and using the software integration system of VB6.0 and FLAC3D, shield tunnel excavation face stability is analyzed with and without the consideration of seepage effect of water. According to the stability theory, the limit face pressure is that when face pressure is changed very small, displacement of the center at tunnel face increases large suddenly. And the changes of the support pressure, the stress field, the displacement field and the plastic zone are obtained under two kinds of conditions. The results show that the limit support pressure of face is equal to the total of the effective pressure and seepage force, the support pressure is larger with the consideration of seepage effect than without the consideration of seepage effect, the seepage force is the main of the limit support pressure; because of the pore water pressure, the stress of the tunnel face when considering the seepage effect is lower than without the consideration of seepage effect, the displacement and the plastic zones when considering the seepage effect is much bigger than that without the consideration of the seepage effect ; and the stability of the face when considering the seepage effect is worse than without the consideration of the seepage effect. Comparison between the simulated results and the observed ones shows the software system is rational and valid and can provide useful reference to the setting of tunnel face support pressure in design and construction.

关 键 词：渗流 开挖面稳定 极限支护压力 软件集成 盾构隧道 

分 类 号：U455[建筑科学—桥梁与隧道工程]