基桩的临界屈曲模态跃迁

考虑桩侧土摩阻力和水平抗力,建立基桩在轴向压力作用下的平衡方程.通过假设桩侧土阻力沿桩长均匀分布,水平抗力为弹性地基模型,采用级数法对基桩的屈曲问题进行求解.通过数值算例,分析水平抗力沿桩长分别为均匀分布和线性分布的情形下,两端铰支基桩的稳定性问题,重点讨论基桩在桩侧土抗力和摩阻力作用下的临界模态跃迁的现象.结果表明,由于桩侧土水平抗力的存在,使得基桩的临界屈曲荷载不一定是一阶屈曲模态所对应的屈曲荷载值.

Critical buckling mode transition of piles

The equilibrium equations of a pile under the action of axial force was established by taking into account the friction of pile side-soil and soil horizontal resistance.Assuming that the axial distribution of frictional force of pile side-soil was uniform and the soil horizontal resistance conformable to elastic foundation model,the pile buckling problem was solved by using series method.In the case of either uniform or linear axial distribution of horizontal soil resistance,the stability problem of the pile with hinged supports on the two ends of the pile was analyzed.The phenomena of critical buckling mode transition of the pile subject to the action of side-soil resistance and frictional resistance was emphatically discussed.The result showed that due to the existence of the horizontal soil resistance,the critical buckling load of the piles was not necessarily the buckling load corresponding to the first-order buckling mode.