螺纹桩负摩阻力计算方法

Calculation and Research on Negative Skin Friction Resistance of Screw Pile

螺纹桩特殊结构形式,使得其更容易产生较大的负摩阻力。对螺纹桩负摩阻力的研究具有重要的理论和工程实际意义。首先讨论了螺纹桩负摩阻力的产生机理及其主要影响因素。并利用佐藤悟双折线模型,通过荷载传递法建立出螺纹桩负摩阻力的基本微分方程。利用连续和边界条件解出桩土相对位移解析式,进而推导出桩身轴力、中性点位置及负摩阻力计算公式,为螺纹桩的进一步研究应用提供一定的理论支持。

Greater negative skin friction resistance exists more easily on screw pile because of its special struc- ture style when the soil around pile moves downward relative to the screw pile. So the research on negative skin friction resistance of screw pile is getting more and more important for its theoretical and practical significance of project. Through theoretical analysis, the generation mechanism and main factors of negative skin friction resistance of screw pile are discussed at first, Kezdi＇ s double-broken-line model and load transfer method are used to estab- lish the differential equation of negative skin friction resistance along screw pile. The boundary and continuous con- dition is used to work out the analytic formula of pile-soil relative displacement, and then, the formula of the posi- tion of neutral point , axel force and negative skin friction resistance. Theoretical support is provided for further study and application of screw pile.