基于桩-土联合结构理论的摩擦桩承载力研究

Study on Bearing Capacity of Friction Pile Based on Theory of Pile-soil Joint Structure

钻孔灌注桩基础是目前应用最为广泛的基础形式,现行规范对其竖向承载力计算存在一些疏漏。以桩-土联合结构模型为基础,将桩-土相互作用形象概化为并联弹簧变形分析,确定了桩桩-土间传力模式;分析了桩侧极限摩阻力产生的原因及所谓极值的局限性,并初步验证了试桩中桩侧土软化现象。最后通过案例验证了运用本模型可以对桩径、桩长进行合理选择,避免超长桩的产生。

Bored pile is the foundation most widely used at present,however,there exist some omissions in respect of calculation of its vertical bearing capacity in current code.Herein based on the model of pile-soil joint structure,the pile-soil interaction was generalized into deformation of parallel springs visually to determine the pile-soil load transfer mode;the causes of utmost side resistance of pile and the limitation of the so-called extreme value were analyzed;and the softening of soil on pile side was verified initially in pile test.At last,the model was proved through case studies to make a reasonable choice of pile diameter and length and getting out of the occurrence of supper-long pile in the works.