摘要
建立了成层土中超长桩考虑桩土相互作用的三维非线性有限元数值模型,选取摩尔库伦准则为土体本构模型,通过对计算域、地应力平衡、边界条件等设定,使结构能反映实际工作情况,并与试验结果进行对比,验证了模型的准确性。模拟计算了单桩在地基预压工况下的竖向受力模型,地基预压后,桩侧摩阻力会因桩周土体应力增加而得到明显强化,所以桩基承载力有所提高,但预压对桩侧摩阻力的增大效果受到土体性质的影响,且预压荷载对土体的影响一般随着深度的加大而减弱。在单桩模型的基础上模拟计算了3×3群桩在地基预压工况下的竖向受力模型。通过改变预压地基的范围和预压荷载大小研究超长群桩在竖向荷载作用下承载力、桩顶Q-S曲线、桩侧摩阻力的变化。
A 3D nonlinear finite element model is built for super-long pile driven into stratified soil under the interaction of soil and pile.The criterion of Mohr-Coulomb is selected as the constitutive model of soil mass.Furthermore,the model can reflect the actual working state by setting the calculation domain,geostress equilibrium and boundary conditions.The model is verified accurate by comparing with the experimental results.The vertical load of mono-pile is calculated under the condition of preloading subgrade.Pile lateral friction obviously increases with the increment of soil stress around the pile after preloading subgrade,thus the pile bearing capacity increases.But the increase of pile lateral friction by preloading is limited by soil properties,and the pre-load generally weakens with the increased depth.A vertical load of 3×3 pile cluster is simulated under the condition of preloading subgrade based on mono-pile model.The area and load of the preloading subgrade can be changed to study such properties of super-long pile cluster as the bearing capacity,Q-S curve of pile top and pile lateral friction under vertical load.
作者
蔡晨雨
苏俊剑
Cai Chenyu;Su Junjian(Shanghai Waterway Engineering Design and Consulting Co.,Ltd.,Shanghai 200120,China)
出处
《港口航道与近海工程》
2024年第1期80-86,共7页
Port,Waterway and Offshore Engineering
关键词
桩
地基预压
承载性状
桩侧摩阻力
数值模拟
piles
preloading subgrade
bearing behavior
pile lateral friction
numerical simulation
