复合地基在沉管隧道基础设计中的应用探讨

在对沉管隧道地基处理中两端陆域边界条件、纵横向荷载分布、地层受力特点、差异沉降控制及施工偏差等主要影响因素分析的基础上,对散体材料桩复合地基、柔性桩复合地基、刚性桩复合地基在沉管隧道地基处理中的适用性进行了多项目对比分析;总结给出了各种复合地基处理方法的适用条件,并提出了沉管隧道采用复合地基方案时,设计计算中应引起高度重视的几个关键问题;最后引用国内外已建或在建的沉管隧道工程复合地基应用的典型实例,进一步说明复合地基在沉管隧道地基处理中将会有较为广阔的应用前景。

Discussion on Application of Composite Foundation in Foundation Design of Immersed Tunnel

The major influences of ground improvement for immersed tunnel have been analyzed,such as boundary conditions of land area,load distribution in longitudinal and transversal directions,soil layer characteristics,differential settlements control and construction deviation.Based on the analysis,the comparison study for applicability of immersed tunnel foundation has been conducted between granular material composite foundation,flexible columns composite foundation and rigid piles composite foundation.Applicable scope of kinds of composite foundations for immersed tunnel has been summarized and several key issues have been paid high attention to during design calculation being proposed for composite foundation of immersed tunnel.Through finished and on-going projects of immersed tunnels adopting composite foundations,the application of composite foundations will have wide range of application in immersed tunnels.