某工程大直径刚性桩复合地基设计及沉降计算方法探讨

Design of Composite Foundation With Large Diameter Rigid Pile and Discuss for Settlement Calculation

深圳市龙岗区某高层公建项目,因塔楼范围跨越不同地质覆盖层,采用桩基础时因沉降差异较大,塔楼倾斜率大于规范要求,通过计算和研究后,采取了大直径刚性桩复合地基基础方案。为防止采用复合地基顶部褥垫层调节塔楼的差异沉降的做法"矫枉过正",需对大直径刚性桩复合地基基础在设计及计算时桩、土承载力分配、复合地基基床系数取值、桩沉降计算的相关参数取值、规范中沉降计算的方法进行分析,合理取值。结合工程实例,对上述问题做了一些分析和研究,得出一些做法和建议,为类似工程参考借鉴。

A high-rise building is located at Long Gang district in Shenzhen.Its tilt rate exceeds to the specification requirement with using pile foundation.The high settlement difference due to different kinds of foundation within the superstructure leads to the high tilt rate.Finally,after comparison,the composite foundation with large diameter rigid pile is adopted.In order to prevent hypercorrection on adjusting settlement differences,more analysis and calculation about the distribution of bearing capacity between pile and soil,coefficient of subgrade reaction,relevant parameters for pile settlement calculation and the calculation method about the settlement is necessary.Details based on this project will be described as follow.