基桩竖向荷载传递模型及承载力研究

Study on the Load Transfer Model and the Bearing Capacity of Vertically Loaded Piles

通过对桩侧荷载传递机理的分析,建立出一种改正的能综合考虑实际工程中桩周土体加工软化和加工硬化等不同性状、桩侧阻的深度效应、不同桩侧土类以及不同成桩工艺等因素影响的桩侧阻、桩端阻荷载传递模型.以荷载传递解析法为基础,分别考虑桩顶沉降处于弹性、弹塑性或塑性等状态,导出了以桩顶沉降量控制基桩竖向承载力的一系列公式,并开发出相应的计算程序,由此可通过控制桩顶沉降量来确定基桩的桩顶竖向承载力.将该计算方法用于某工程现场静载荷试桩对比分析,理论与实测结果吻合良好.

Based on the analysis of the load transfer mechanism of shaft resistance, an improved load transfer model of shaft resistance and tip resistance was put forward.This model could take into account quite a few factors, such as the softening or hardening behavior of the soil, the depth effect of shaft resistance, the influence of various types of soils and different construction techniques of pile. Then through the use of the improved model with consideration of different status of the pile top settlement (i.e. elastic, elastic-plastic and plastic), a series of formula were deduced to determine the vertical bearing capacity of pile according to the settlement of pile top. Corresponding calculating programs were also worked out. Lastly, the present method was applied to analyze the measured data from a field-loading test on an instrumented pile, and the theory agreed with the calculated results.