一种根据Q-S曲线辅助分析桩身极限摩阻的方法

A New Method of Assisted Analysis of the Ultimate Shaft Resistance of Pile According to the Q-S Curve

根据Q-S曲线特征确定桩身极限摩阻通常最准确的做法为应力测试法,但造价较高,难以在实践中推广应用。本文根据加荷过程中桩身的应力特征进行了等效理论分析,推导出了根据Q-S曲线数据分析桩身极限摩阻的公式,通过f-Q曲线最大值点可以定量给出桩身极限摩阻值和桩身等效单位摩阻值,另根据f-S曲线特征还可给出对应于极限摩阻的桩顶位移量,为摩擦型桩Q-S曲线承载力分析提供了一种新的辅助方法。

The common practice,which determines the ultimate shaft resistance of pile according to the Q-S curve,is geometric graphic solution.The graphic solution is simple,but the theory is not clear and the results vary from person to person,so it is difficult to promote application in practice.According to the stress characteristics around pile,the paper carries on theoretical analysis and derives a formula to analyse the ultimate shaft resistance of pile according to the Q-S curve.According to the maximum points of the f-Q curve,the formula can determine the ultimate shaft resistance of pile accurately,and obtain the equivalent unit of shaft resistance of pile corresponding with the ultimate shaft resistance of a single pile at the same time.