This study investigates the load transfer mechanism that includes the effect of helix bending deflection on end-bearing capacity, distribution of ground pressure under the helix and soil deformation around the screw pile. The helix to shaft diameter ratio of 2.5 and 2.8 with a strong helix and a weak helix were used. The model ground was prepared with fine sand at 80% of relative density. To investigate the load transfer mechanism, the experimental tests were modelled in a 3D finite element code. A good agreement between the experimental and numerical approaches was found. The numerical analyses showed that large influence zone exists under screw pile with strong helix, which resulted in higher mobilized soil shear strength that contributed to higher end-bearing capacity. In the case of strong helix, uniform pattern of pressure distribution was observed under the central shaft and the helix. Similar pattern of pressure distribution under the central shaft was observed in weak helix case but the pattern of pressure distribution under the helix changed from uniform to triangular to trapezoidal at various stages during the load test. The normalized end-bearing capacity decreased linearly with the increase in normalized helix bending deflection in both approaches, i.e. experimental and numerical.

本研究研究了荷载传递机制，包括螺旋弯曲挠度对端部承载力的影响、螺旋下地压分布和螺旋桩周围土壤变形。使用了具有强螺旋和弱螺旋的 2.5 和 2.8 的螺旋与轴直径比。模型地基用80%相对密度的细砂制备。为了研究载荷传递机制，实验测试在 3D 有限元代码中建模。发现实验方法和数值方法之间有很好的一致性。数值分析表明，强螺旋螺旋桩下存在较大的影响区，导致较高的动土抗剪强度，有助于提高端部承载力。在强螺旋的情况下，在中心轴和螺旋线下观察到均匀的压力分布模式。在弱螺旋情况下观察到中心轴下方的压力分布模式类似，但在负载测试期间的各个阶段，螺旋下方的压力分布模式从均匀变为三角形到梯形。在两种方法中，即实验和数值方法中，归一化端承载能力随着归一化螺旋弯曲挠度的增加而线性下降。