被动桩—土相互作用的简化分析

首先简要地分析了地面堆载作用下处于被动状态下的桩及桩侧土的反应,基于桩和土的变形协调条件,确定了桩侧土压力表达式。在此基础上,建立了桩身挠曲的控制微分方程,并联合采用非线性p y关系曲线与有限差分法进行求解。通过算例分析,验证了所建议分析方法的合理性和实用性。最后对影响被动桩—土相互作用体系工作性能的各种因素进行了系统的对比计算与分析。

A Simplified Analysis of Interaction of Soils and Pile in Passive State

Study on interaction of soil and pile in passive state has been increasingly carried out for several years. The majority of piles are designed to support "active" loadings, however, in some cases the piles have to withstand "passive" loading, such as loads induced by lateral movement of soils surrounding the piles under ground surcharge or building construction. In this paper, reaction behaviors of passive pile and surrounding soils under surcharge applied at the ground surface are investigated respectively. Based on the compatibility condition of deformation of pile and surrounding soils, the formulae of lateral earth pressure on pile is presented. And then the partial differential equation governing deflection of pile is established and is numerically solved by combining non-linear p-y relationship curve of pile and finite difference procedure. Through an example analysis, the reasonableness and applicability of the proposed method are verified. It is shown that this simplified method will be useful in evaluating the interaction behavior of pile and soils in passive state. Comparative computations are made for different combinations of various related parameters to examine the effects of these factors on the performance of passive pile under surcharge.