非线性土中单桩P—Δ效应有限元法计算分析

基于地基土线性假定的单桩P-Δ效应分析研究较多，但基于地基土非线性假定的单桩P-Δ效应分析研究极少。为此，提出等效多段折线弹簧模拟非线性地基土的P-γ曲线，应用有限元法进行非线性地基土中单桩P-Δ效应分析。同时对等效多段折线弹簧模拟非线性地基土P-γ曲线的具体细节进行了总结，以确保计算精度。最后，应用MidasCivil程序建立了有限元模型进行了算例分析。结果表明，等效多段折线弹簧模拟P-γ曲线后应用商业程序计算基桩P-Δ效应是非常便捷的方法，具有工程实际意义。

Analysis of P-A Effect of Pile in Nonlinear Soil by Finite Element Method

Many methods have been developed and applied to analysis of P-Δ effect of piles in soils with linear property, while few have been developed and applied to analysis of P-Δ effect of piles in soils with nonlinear property. Therefore equivalent springs are applied to simulate p-y figure of nonlinear clay, and then the P-Δ effect of pile is analyzed by finite element method. The steps of how to simulate p-y figure of nonlinear clay is presented in the paper. Case analysis is done for displacement and stress calculation of pile in nonlinear clay with P-Δ effect well considered by finite element method. Fi- nally conclusions are drawn as follows： （i） finite element method can well done in software, and is proved to be a effective method for P-Δ effect analysis of pile foundation in nonlinear clay; （ii） finite el- ement method will be popularized in engineering for analysis of P-Δ effect analysis of pile foundation in nonlinear clay.