基于 FLAC3D 数值分析软件，探讨了大直径长桩的数值模拟方法，分析了桩土间接触面参数对数值计算结果的影响。结果表明：桩侧接触面的内摩擦角和粘聚力对桩的承载性能影响较大，而剪切刚度的影响存在一临界值；水平荷载下，需考虑桩侧接触面参数对桩与桩侧土体之间摩阻力的影响；竖向荷载下，需考虑剪切刚度随深度的变化；倾斜荷载下，需考虑桩端土的剪切作用。

The numerical simulation method based on software FLAC^3D for the large-diameter long pile is discussed, and the influences of parameters of soil-pile interface on the numerical results are analyzed. The results show that the inner friction angle and cohesion on the pile side have great influences on the bearing behavior of the pile, while a critical value exists for the influence of shear stiffness. It is required in the calculation to consider: under a horizontal load,the influences of parameters of pile side interface on the friction between the pile and pile side soil ； under a vertical load,the changes of shear stiffness coefficient with depth ； and under a inclined load,the shearing effect of the soil on the pile end