变截面桩的屈曲分析

以锥形桩为例，用能量法对变截面桩的屈曲问题进行了深入研究．首先建立了锥形桩的力学分析模型，并通过选取适合于边界条件的桩的合理挠曲位移函数，导出了系统总势能的表达式；然后利用最小势能原理推导了锥形桩屈曲临界荷载的计算公式．大量计算表明，在其他条件相同的情形下，变截面桩较普通等截面桩稳定性好，且锥形变截面桩存在一最不利桩长，在设计桩长时，应避开此最不利值．

Buckling Analysis of the Variable Section Piles

With the example of taped pile, the buckling problem of variable section piles was analyzed with the energy method. Firstly, the mechanical model of the taped pile was established, proper pile deflection function satisfying the boundary condition was chosen to deduce the total static energy of the system; and the formula of the buckling load was derived with the minimum potential energy principle. Numerical calculations indicated that the stability of the variable section pile was better than that of the constant section pile under similar conditions, and there existed a most disadvantageous pile length of taped pile. This value should not be selected in designing.