粉质黏土中缩径单桩静压沉桩阻力数值模拟研究

NUMERICAL RESEARCH ON STATIC SEDIMENTATION FOR REDUCED DIANETER MOMOPILE FOUNDATION IN SILTY CLAY

室内缩尺试验较难真实还原其沉桩特性,原型试验又较为耗时,基于耦合的欧拉-拉格朗日(CEL)数值分析方法可实现原比尺模型静压沉放过程模拟,且可直观获得桩-土相互作用过程。通过室内试验进行沉桩阻力的有限元方法验证,并将有限元法用于工程体型沉桩过程模拟与阻力计算;数值模拟结果表明,缩径段的体型设计使沉桩阻力增加,EVF云图可看出进入桩内土体的体积减少,使桩内出现泥面降低的情况;最后,研究不同缩径段尺寸对于沉桩阻力的影响。

Reduced diameter monopile,as an emerging type of supporting structure for offshore wind turbines,it is very significant for engineering applications to calculate the sinking resistance of this stage.The laboratory scale test is difficult to truly restore the sinking characteristics,and the prototype test is time-consuming and labor-intensive.The Coupled Eulerian-Lagrangian(CEL)numerical analysis method can realize the static sedimentation process simulation of the original scale foundation.Based on the experiment results,the CEL numerical method is validated and applied to a simulation of an engineering prototype.The numerical simulation results show that the reduced diameter design increases the pile sinking resistance,and the EVF cloud image shows that the volume of soil entering the pile decreases,resulting in the reduction of the mud surface inside the pile.Finally,the influence of different sizes of reduced diameter monopiles on pile sinking resistance is studied.