(广东省建筑设计研究院，广州510010)
［提要］广州地铁五号线大坦沙站工程处于石灰岩地区，岩溶发育、连通，岩面以上全为软土层，地下工程施工风险极大。设计采用灵活布置的深层搅拌桩，既加固了基坑被动区，又降低了坑底突水的风险，同时提高了地基承载力。并提出了防止止水帷幕薄弱处渗流的措施和桩基穿越溶洞的方法，实施效果好。考虑水土压力的地下结构整体模型的有限元分析，较为真实地反映了实际受力状态。屋面采用由三角桁架与弧形刚架组成的钢结构屋面，轻巧、美观。
［关键词］基坑支护；地基加固；溶洞处理；整体计算；钢桁架
Structural Design of Datansha Station of Guangzhou No.5 Metro Line/Zhou Peihuan, Chen Yingrong(The Architectural Design and Research Institute of Gangdong Province, Guangzhou 510010， China)
Abstract:The project is located in limestone area where karst is developed and intercommunicated, and the soil above the rock are all mollisol, so the construction risk is extremely high. The design adopted flexible layout of deep-mixing piles is introduced, which could strengthen the passive zone, reduce the risk of seepage and piping in the pit and increase the bearing capacity of the foundation. The measures to avoid seepage in unsubstantial zone of seepproof screen and the treatment for piles penetrating caves are mentioned. The analysis of integral underground model in which the water and soil pressures are both involved, which can accurately reflect the practical mechanical behaviors, the design of steel roof consisting of triangle truss and arc frame are also introduced.
Keywords: supporting; foundation strengthen; karst cave treatment; integral analysis; steel sunshade