按单桩极限承载力设计复合桩基方法的可靠度分析

Reliability analysis of design method of composite pile foundation according to ultimate bearing capacity of single pile

从按单桩极限承载力设计复合桩基的总安全度方法出发,运用可靠度理论,结合工程实例,建立了用该法确定的承载力极限状态方程,进行了可靠度分析与验证。对抗力及各基本变量的敏感性、设计参数不同组合时的安全系数与可靠度指标的关系进行了全面的分析,研究了天然地基承载力满足率ψ 的合理取值范围,证实了天然地基满足率ψ ≥0.5 的必要性。

Based on the design method of composite pile foundation according to the ultimate bearing capacity of single pile, and combined with a real project, reliability theory is used to analyse reliability of composite pile foundation. The further research is carried out from the aspects such as sensitivity of basic variables, the relationship between index of reliability and safety factor aiming at combination of different coefficients, the contribution to reliability with the change of each coefficient, and so on. This article also suggests the reasonable range of ψ the satisfying rate of bearing capacity of nature foundation, and proves that ψ≥0.5 is necessary.