为了研究大锚片螺旋锚在粉质黏土中竖向受压荷载下的受力性能，基于螺旋锚现场静载试验，讨论了确定其极限承载力方法的差异；考虑螺旋锚对周边土的挤压效应，建立了精细化有限元模型，并将数值分析结果与试验结果进行对比，验证了有限元模型的合理性；基于验证的有限元模型，分析不同荷载等级下沿基础深度范围内的锚杆内力和侧摩阻力的变化规律，以及侧阻和锚片端阻承担荷载的比例关系。研究结果表明：用lgP-s方法确定大锚片螺旋锚基础极限受压承载力较合适；螺旋锚与土之间的摩阻力随下压位移的增加而增大，锚片附近区域的摩阻力由于锚片变形而发生较大的波动；螺旋锚锚片分担荷载的比例占据螺旋锚基础受荷的75%以上，各锚片间分担荷载比例最大差异约为6%，锚杆端阻可忽略不计。

In order to study the mechanical performance of screw anchor under vertical compression load in silty clay area, firstly, based on the static load test of screw anchor, the differences of methods for determining its ultimate bearing capacity at home and abroad are discussed respectively; secondly, a refined finite element model is established for screw anchor, in which the compression effect of screw anchor on surrounding soil is considered, and the numerical analysis results and test results are compared; finally, based on the verified finite element model, the change rule of anchor internal force and side friction resistance along the range of foundation depth under different load levels is analyzed, as well as the proportion relationship between side resistance and anchor end resistance bearing load. The results show that the lgP-s method is suitable to determine the ultimate bearing capacity of the screw anchor foundation with large anchor pieces; the friction between the screw anchor and the soil increases with the increase of the down-force displacement, and the friction near the anchor plate fluctuates greatly due to the deformation of the anchor plate; the proportion of load shared by anchor pieces accounts for more than 75% of the load of the screw anchor foundation, the maximum difference of load shared by each anchor piece is about 6%, and the end resistance of screw anchor foundation can be negligible.

TU476

国家电网有限公司科学技术项目（SGHAJG00AJJS1900148）；河南省高等学校重点科研项目（20A560007）