基于稳定分析法的碎石桩复合地基承载力的可靠度

Reliability of bearing capacity of composite foundation based on stabilization analysis

采用圆弧滑动稳定分析方法 ,按实用的优化方法计算碎石桩复合地基承载力的可靠度指标 ,并讨论了建立在可靠度基础上的复合地基置换率的设计问题 .所用的可靠度计算公式直接在基本变量空间中求解 ,避免了繁琐的求偏导数和正交变换工作 .并且在分析中考虑了模型不确定性的影响 .由于在稳定分析时 ,最危险滑弧事先并不知道 ,所以用优化方法求可靠度指标有巨大的优越性 .本文利用 Microsoft Excel97中的“规划求解器”来求解安全系数和可靠度指标 .

An arc slip analysis model to calculate the bearing capacity of gravel pile composite foundation is being put forward,a practical optimal method is used for reliabiliy analysis, and the reliability based replacement ratio design is also considered. The formula of reliability index is calculated in the origin space directly, so derivation and orthogonal transformation are avoided. Model uncertainty is take into account in this paper. Because the searching of critical slip arc is needed in the limit equilibrium analysis, using the optimal method to obtain the reliability index has immense advantages. The Microsoft Excel 97[KG-4]s Solver is used for calculating the safety factor and the reliability index. In the end, an example is used to illuminate the analysis process.