边坡段水平受荷桩桩前土抗力折减效应的模型试验研究

Model Testing Study on Effect of Predicament Resistance Reduction on Lateral Loaded Pile near Slope

为解决由于边坡存在造成的土抗力折减问题,开展了黏性土中平地及不同边坡条件下的基桩水平加载室内模型对比试验.试验结果表明,两种工况下水平受荷桩的荷载变形曲线及内力变化规律基本一致,但位于坡体上的基桩的承载能力明显折减,而该折减效应与边坡角度及桩位于边坡的位置紧密相关.进一步量化分析了土抗力折减效应的影响因素,提出了折减效应与桩位于边坡的位置和边坡角度的定量关系.在此基础上,通过对坡体上极限土抗力和初始刚度的合理修正,建立了可考虑边坡处土抗力折减效应的水平受荷桩的p-y曲线计算公式.理论计算值与已有的试验结果的对比表明两者吻合较好.

In order to solve the problem of soil resistance reduction caused by the existence of slopes, this paper carried out a comparison test of the horizontal loading model on the foundation piles in the flat soil and different slope conditions of the clay soil. The test results show that the load deformation curve and internal force variation of the laterally loaded piles under two conditions are basically the same, but the bearing capacity of the piles located on the slope body is obviously reduced. However, the reduction effect is closely related to the slope angle and pile location in the slope. The influencing factors of the soil resistance reduction effect are further quantitatively analyzed,and the quantitative relationship between the reduction effect and the position and slope angle of the pile in the slope is proposed. On this basis, the p-y curve formula of lateral loaded piles that can consider the soil resistance reduction effect at the slope is established by reasonably correcting the ultimate soil resistance and initial stiffness of the slope. The comparison between the theoretically calculated value and the existing experimental results shows that these two agree well with each other.