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扩底楔形桩具有单位材料利用率高、竖向桩侧摩阻力和桩端阻力较常规等截面桩高的技术优点。然而,针对该桩型竖向及水平向承载力的定量模型试验研究相对较少。基于模型试验方法,开展砂性土中竖向、水平向荷载以及地面堆载等不同形工况荷载作用下扩底楔形桩的承载特性试验,测得不同荷载等级下桩侧摩阻力、桩端阻力、侧向土压力、桩顶下拽位移以及桩身下拽力等分布规律;同时,开展等混凝土用量常规等直径桩的承载特性试验作为对比分析,初步探讨了两种桩型的受力机制与异同点。研究结果表明,试验条件下,扩底楔形桩的单桩竖向承载力约为等直径圆桩的2.33倍,表现出侧阻力和端阻力都优于圆形桩的特点;水平承载力约为等直径圆桩的1.48倍,上部直径较大和扩大头的存在提高了其水平承载性能;与等直径圆桩相比,楔形角的存在可有效降低桩顶下拽位移,可见把传统桩型转变成扩底楔形桩是降低负摩阻力对桩基影响的有效方法之一。
Bottom wedge-shaped pile with high unit material utilization, vertical pile side friction and pile tip resistance than conventional cross-section pile high technical merits. However, the quantitative model tests for vertical and horizontal bearing capacity of the pile are relatively few. Based on the model test method, the bearing behavior of wedged piles under vertical and horizontal loads and under different load conditions such as ground loading were investigated. The frictional resistance of pile under different load classes, Resistance, lateral earth pressure, displacement under the top of the pile, and the drag force of the pile. At the same time, carrying out the test of bearing capacity of conventional equal-diameter piles with constant amount of concrete as the comparative analysis, Mechanism and similarities and differences. The results show that under the test conditions, the vertical bearing capacity of single wedged piles with wedged piles is about 2.33 times that of circular piles of equal diameter, which shows that both lateral resistance and end resistance are superior to circular piles. The horizontal bearing capacity is about Compared with the equivalent diameter circular piles, the presence of wedge angle can effectively reduce the displacement of the top of the piles, which shows that the traditional pile type transformation One of the effective methods to reduce the influence of negative skin friction on the pile foundation is to form a wedged piling with a bottom.