群桩效应有限元分析

Finite element analysis of effect of pile group

利用有限元方法,对竖向荷载作用下复合桩基的群桩效应进行了计算分析,讨论了桩长 L、桩距与桩径之比 Sa/d、桩数 n、土类等对群桩效应及群桩效应系数η的影响。结果表明:复合桩基中各个基桩的极限承载力 Qu及η随 L 增大而增大;当 Sa/d 小于某个数值时,Qu,η随 Sa/d 增大而增大;当 Sa/d 大于某个数值时,Qu,η随 Sa/d 增大而减小。群桩效应及η与土类有关;η存在极大值,随 n 增多而减小,但减幅不大。

Using the finite element method, the paper is mainly focused on the effect of pile group and its effect coefficient (η) of the composite pile foundation. Some influential factors, such as the pile length (L), the ratio of the pile spacing to the pile diameter (Sa/d), the pile number (n) density and soil type etc., are introduced and their effects on the effect of pile group and its effect coefficient, are analyzed, respectively. The results indicate that: the bearing capacity of the single pile (Qu) and the effect coefficient of pile group (η) both increase with the pile length (L), and decrease with pile number (n). While the ratio of the pile spacing to the pile diameter (Sa/d) is a fixed quantity, the Qu and the η will achieve maximum. The effect of pile group and its effect coefficient (η) of the composite pile foundation is correlated with the soil type.