水下盾构隧道渗流场应力场耦合效应研究

Research on coupling seepage field and stress field analyses of underwater shield tunnel

在高水压条件下施工水下盾构隧道,渗流场对于结构及围岩应力场有很大影响。结合重庆主排水过江盾构隧道的修建,针对不同水压情况下的盾构隧道,采用有限元法对围岩及结构的渗流场和应力场进行耦合分析,获得施工期管片应力、位移及孔隙水压力分布。重点研究了管片的水压力分布规律,并与现场试验进行相互验证。结果表明:耦合效应下隧道管片需要承担更大的拉力,在设计中应按更不利工况进行配筋。所得结论为类似工程的设计施工提供有了益参考及依据。

Seepage field has a great influence on stress field of shield tunnel structure during construction under high water pressure. The FEM has been used to analyze the coupling seepage field and stress field under different water pressures based on the drainage tunnel project crossing the Yangtze River at the downtown of Chongqing city. The segment＇s stress distribution, displacements and pore pressure distributions are calculated. Water pressure distributing rule has been studied emphatically; and the results are verified by the in-situ data. The calculation show that segments need to take more tensile force under coupling effect. The achieved results offer helpful reference and basis for design and construction of this project.