竖向荷载作用下复杂群桩的变形及荷载分布

以厦深(厦门—深圳)客运专线韩江特大桥潮安县段桩基选型工程为研究背景,通过有限元软件ABAQUS进行数值仿真模拟,分析低承台超长桩在非均质土条件下承受竖向荷载时竖直桩基的荷载-沉降(Q-S)曲线、基桩荷载分担、桩体侧向受荷、承台偏移、基桩竖向变形等工作性状。结果表明:超长群桩的Q-S曲线呈缓变特征,未出现显著的转折点和陡降;在承台顶逐级施加荷载作用下在同一深度范围内桩身轴力中桩、边桩、角桩依次增大;角桩和边桩的竖向变形相似,中桩差别较大;桩身的压缩变形随桩体深度依次递减;中桩侧摩阻力与周围基桩相比较小,变化更加缓慢。

Deformation and Load Distribution of Complex Pile Group Under Vertical Load

Taking the pile foundation selection project of Chaoan county section of Hanjiang super bridge in Xiamen-Shenzhen passenger dedicated line as the research background,the working characters including load-settlement ( Q-S ) curve of vertical pile foundation,load sharing of foundation pile,lateral load of pile body,cushion cap offset and vertical deformation of foundation pile were analyzed when the low cushion cap super-long pile was subjected to vertical load in heterogeneous soil conditions through numerical simulation with f inite element software ABA Q US.The results show that the Q-S curve of the super-long pile group shows a slowly varying characteristic and there is no signif icant turning point and steep drop,under the loading action of the cushion cap top step by step,the axial force of the middle pile,side pile and corner pile increases successively in the same depth range.Vertical deformations of corner pile and side pile are similar,but are significantly different from that of middle pile.The compression deformation of pile body decreases with the depth of pile body.The side friction of the middle pile is smaller than that of the surrounding foundation pile,the change of which is more slow.