论文部分内容阅读
大直径单桩是用于海上风力机的一种典型基础形式.波浪与海流引起的桩基冲刷会削弱桩基的承载能力而危及结构安全.本文建立了模拟桩基与土体相互作用的三维有限元数值模型,并用试验结果对模型进行了验证.基于数值计算结果获得了一系列典型砂土及桩基参数下的桩土相互作用p-y曲线,拟合得到适用于砂土的大直径单桩基础p-y曲线参数化表达式.冲刷所致的桩基埋深变化可导致桩基变形向刚性桩模式转变.数值分析结果表明,刚性桩变形模式下桩基底面和桩基侧壁切向的土阻力对桩基承载力产生重要影响,而目前仅考虑桩土间水平作用力的p-y曲线法所预测的桩基变形偏大.对于距冲刷后泥面同一深度处的土体,p-y曲线的斜率随着局部冲刷深度的增加而逐渐增大,变化规律与基于离心机实验结果一致.随着冲刷坡角的减小,局部冲刷坑周围土体对桩基的约束逐渐弱化,p-y曲线修正方法中参数f的取值也逐渐减小.
Large-diameter single pile is a typical foundation for offshore wind turbines. The pile foundation scouring caused by wave and current can weaken the bearing capacity of the pile and endanger the safety of the structure.This paper establishes three-dimensional The finite element numerical model is established, and the model is validated with the test results.A series of py curves of pile-soil interaction under typical sand and pile parameters are obtained based on the numerical calculation results, and the large diameter single pile The parametric expression of the basic py curve, the change of pile depth caused by erosion can lead to the change of the pile deformation to the rigid pile mode.The numerical analysis shows that the deformation of the pile foundation and the side wall of the pile Resistance has a significant influence on the bearing capacity of the pile, but at present, the deformation of the pile foundation, which is only predicted by the py curve method considering the horizontal force between pile and soil, is too large.For the soil at the same depth from the mud surface after scouring, the slope of the py curve With the increase of local scour depth and gradually increased, the variation rule is consistent with the experimental results based on centrifuge.With the reduction of scouring slope angle, the soil around the local scouring pits constrained by the pile Weakening, p-y curve correction process parameter values f gradually decreases.