基于有限元对螺纹桩极限承载力影响因素的研究

Study on the Influence Factors of Ultimate Bearing Capacity of Screw Pile Based on Finite Element Method

为了研究螺纹桩结构参数对螺纹桩极限承载力的影响程度,基于池黄高铁施工路基工程,采用有限元的方法建立了等截面圆桩和螺纹桩以及所对应的桩周土模型,并对其进行有限元计算。结果表明:对比螺纹桩与等截面圆桩的极限承载力和与之对应的位移,螺纹桩的极限承载力为与其内、外径相同的等截面圆桩的2.92倍和1.70倍;在计算范围内,螺纹桩在最佳螺纹密度时的极限承载力是最低螺纹密度时的1.37倍,螺纹桩的桩长影响效果随其长度增长呈线性增加;在计算范围内,螺纹宽度与螺纹外侧厚度使极限承载力产生的最大比值分别是1.22和1.06,与其他因素产生的影响效果相比其值较小,因此在施工实践中,可根据技术水平选取合适的参数。

In order to study the influence degree of the structural parameters on the ultimate bearing capacity of the screw pile,based on the construction of subgrade project of the Chihuang High-speed Railway,the finite element method is used to establish the model of the round pile with equal section,the screw pile and the corresponding soil around the pile,and the finite element calculation is carried out.The results show that,by comparing the ultimate bearing capacity and the displacement,the ultimate bearing capacity of the screw pile is 2.92 times and 1.70 times that of the circular pile with the same inner and outer diameters.Within the calculation range,the ultimate bearing capacity of the screw pile at the optimal thread density is 1.37 times that at the lowest thread density,and the influence effect of pile length of the threaded pile increases linearly with the increase of its length.In the calculation range,the maximum ratio of the thread width and the thread outer thickness to the ultimate bearing capacity is 1.22 times and 1.06 times,respectively.Compared with the influence effect of other factors,the value is small,so appropriate parameters can be selected according to the technical level in construction practice.