群桩扭转非线性模型

Nonlinear analysis of pile groups subjected to torsion

建立了一个非线性数学模型来分析群桩扭转问题。该模型利用非线性荷载传递曲线来模拟桩的非线性响应,采用Mindlin解计算各桩水平力间的相互作用,用Randolph解析解分析得到各桩间扭矩对水平力的影响。在各单桩中引入经验性的耦合系数,分析桩身水平变形引起的土体反力对该桩扭转承载力的影响。对比计算结果与离心机模型试验数据,表明该模型能够模拟群桩扭转中主要的桩-土-桩相互作用和荷载耦合作用,较好地反映了实际情况。

A method is presented to analyze the nonlinear behavior of pile groups under torsion. In this method, the lateral and torsional responses of individual piles in a pile group are modeled by load transfer curves; the far-field interactions among the individual piles in the groups are predicted using classical elastic solutions; and the coupling effect of lateral resistance on torsional resistance of the individual piles is quantified using an empirical factor. The proposed approach is capable of capturing major pile-soil-pile interactions and the coupling effect in pile groups subjected to torsion. It is verified using results of centrifuge model tests.