成层土中长桩竖向承载激发规律研究

针对成层土中长桩承载问题，结合试桩数据建立了成层土中长桩-土相互作用特性分析模型，基于分析模型研究了上砂下黏和上黏下砂中砂-黏占比对长桩竖向荷载-位移曲线的影响，分析了成层土中长桩侧阻和端阻承载分担比，揭示了达到极限承载力时成层土中桩基侧阻、端阻激发规律，即黏土层侧阻可完全激发、砂土层侧阻未完全激发，桩底端阻完全激发，为实际工程中长桩承载力计算选取合理参数提供依据。

Research on Vertical Bearing Excitation Law of Long Piles in Layered Soil

A model for analyzing the interaction characteristics between long piles and soil in layered soil is established based on test pile data to address the bearing problem of long piles in layered soil. Based on the analysis model, the influence of sand to clay ratio on the vertical load displacement curve of long piles is studied. The lateral and end resistance bearing ratios of long piles in layered soil are analyzed, and the excitation laws of lateral and end resistance of pile foundations in layered soil are revealed when the ultimate bearing capacity is reached. It is shown that the lateral resistance of the clay layer can be fully excited, the lateral resistance of the sand layer is not fully excited, and the resistance at the bottom of the pile is fully excited. The results provide a basis for selecting reasonable parameters for calculating the bearing capacity of long piles in practical engineering.