大直径单桩水平循环弱化有限元分析

处于复杂海洋环境下的大直径单桩基础需要承受波流等长期水平循环荷载作用,建立能反映其循环弱化特性的有限元分析方法尤为重要。为此,采用非线性运动硬化准则和饱和软黏土循环弱化模型描述土体循环加载时的滞回特性和强度弱化,并建议了模型参数的选取方法。为验证该本构模型在分析桩土循环弱化时的有效性,先将大直径单桩循环加载有限元模拟结果与离心试验结果进行对比。并进一步研究了循环位移幅值、弱化参数对于大直径单桩基础桩顶反力弱化的影响。

Finite Element Modelling on Degradation of a Monopile Subjected to Cyclic Lateral Loads

monopile foundation under complex marine environment is always subjected to long-term cyclic loads such as wave and currents. Therefore, it is necessary to establish a corresponding finite element analysis method. In this study, a nonlinear kinematic hardening criterion with cyclic degradation characteristic is employed to describe the cyclic hysteresis and softening characteristics of undrained soft clay. A method of determining the model parameters is recommended. By comparing the results from the centrifuge test of a cyclic lateral monopile with those from the finite element simulation, the effectiveness of the model is verified. Finally, parametric studies on the effect of the displacement cyclic amplitude and the softening parameter on the lateral resistance of the monopile are conducted.