大直径灌注桩水平承载特性数值模拟分析

Numerical simulation of lateral bearing capacity behavior of cast-in-place pile with large diameter

由于水平荷载作用下桩土相互作用的复杂性，准确分析桩基水平承载力特性往往较为困难。基于某水平桩现场静载试验，采用有限元软件ABAQUS对试验区单桩进行数值模拟，采用弥散开裂模型模拟混凝土受力性状，用埋入单元模拟混凝土中的钢筋，计算得到位移曲线和桩身弯矩分布曲线并与试验值比较，结果表明：有限元计算PS曲线与实测P-S曲线表现出较好的吻合性，在临界荷载之前有限元计算结果较实测值偏大；有限元计算与实测弯矩沿桩身分布较为吻合，最大弯矩点位置位于泥面以下1/5桩长范围内，反弯点大致位于深度8~12m处。

It is difficult to analyze the lateral bearing capacity behavior of pile foundation accurately, for the interactive mechanism of pile-soil system is quite complex under the lateral bearing capacity. Based on field test of a lateral loaded pile,we carried out the numerical simulation on single pile with finite element software ABAQUS. Constitutive model of concrete smeared cracking was adopted to simulate concrete of pile, and the embedded element was used to simulate rebars in concrete.Calculated bending moment of the pile on different height and the deformation results were compared with experimental results.Simulation results show that: the numerical P-S curve has some difference with the experimental P-S curve, but the change rule meets well with the experimental result, the major difference occur at the stage before the critical load; the numerical bending moment meet well with the experimental results. The position of maximum bending moment is located about 1/5 of the pile length below mud line, and the inflection point is located at the depth about 8~12 m.