引言为了确定桩在相对较小的水平或竖向荷载作用下的动力反应,近年来已经研究出几种方法,在这里土壤可假定为线弹性材料。这些理论得到的结果十分类似,这说明现在对问题的主要特性已有很好的理解。然而早已认识到非线性效应,诸如土壤非线性性能、滑移和可能发生的裂隙等对桩在中等到大振幅的循环荷载作用下的反应起 INTRODUCTION In order to determine the dynamic response of a pile to a relatively small horizontal or vertical load, several methods have been developed in recent years, where the soil can be assumed to be a linear elastic material. The results obtained by these theories are very similar, which shows that the main features of the problem are now well understood. However, it has long been recognized that non-linear effects, such as the non-linear behaviour of the soil, slippage, and possible fractures, are responsible for the reaction of piles to cyclic loads of medium to large amplitude.