中文摘要：

同时考虑桩侧土抗力、桩侧摩阻力和桩身自重的影响,通过选择合适的桩身挠曲变形函数及桩侧土弹性抗力模式,基于最小势能原理,应用瑞利-里兹法求解超长桩的临界荷载,给出了超长桩屈曲荷载和计算长度的解析表达,最后分析了桩侧土抗力、桩侧摩阻力和桩身自重对超长桩屈曲荷载和计算长度的影响.研究结果表明：桩侧土抗力是影响超长桩屈曲荷载的主要因素,而桩侧摩阻力对超长桩屈曲荷载的影响甚微.当桩身埋置率较低时,桩身自重对超长桩屈曲荷载的影响不容忽视,但是随着埋置率的增加,桩身自重对超长桩屈曲荷载的影响逐渐降低.

英文摘要：

Considering the effects of lateral resistance of soil,frictional resistance between pile and soil and self-weight of pile,and choosing proper deflection function of pile and elastic resistance model of lateral soil,the analytical solutions of buckling load and the calculation length of super-long pile were obtained by the method of Rayleigh-Ritz and the theory of minimum potential energy. The effects of lateral resistance of soil,frictional resistance between pile and soil and self-weight of pile on buckling load and calculation length of super-long pile were also analyzed. The results show that the buckling load of super-long pile is mainly influenced by lateral resistance of soil,while the frictional resistance between pile and soil has slight effect on buckling load of super-long pile. When the ratio of depth to length of pile is small,the influence of pile self-weight on buckling load should be considered. The influence of selfweight of pile is gradually decreased with the increasing of the ratio.