扩底楔形桩沉桩施工过程数值模拟分析

发布时间：2018-03-19 21:11

本文选题：扩底楔形桩　切入点：沉桩效应　出处：《铁道科学与工程学报》2014年06期 　论文类型：期刊论文

【摘要】：扩底楔形桩是一种可以有效发挥桩侧摩阻力和桩端阻力、降低负摩阻力影响的新型纵向变截面桩;然而针对其沉桩施工过程中的挤土效应、沉桩阻力等研究则相对较少。基于PFC数值分析软件,建立扩底楔形桩和等体积混凝土用量的常规等截面桩的沉桩施工过程模拟数值模型;通过与等截面桩沉桩模型试验和圆孔扩张理论计算结果的对比分析,验证了本文所建立的数值分析模型的准确性和可靠性;对比分析扩底楔形桩和等截面桩沉桩过程中桩周土体位移场、应力场以及沉桩阻力等变化规律。研究结果表明:沉桩过程中桩端阻力值的大小,不仅与横截面面积有关,而且与桩侧界面形式有关;本文数值模型情况下,扩底楔形桩静压沉桩施工桩端阻力、桩侧摩阻力和整体沉桩阻力分别是等截面桩的1.8,1.1和1.5倍。
[Abstract]:The wedge pile with enlarged bottom is a new type of longitudinal variable section pile which can effectively exert the side friction and the pile tip resistance and reduce the negative friction, however, in view of the soil squeezing effect during the construction of the pile, Based on the software of PFC numerical analysis, the numerical simulation model of pile driving process of conventional pile with equal volume concrete and wedge pile with same volume is established. The accuracy and reliability of the numerical analysis model established in this paper are verified by comparing the results with the model test and the calculation results of circular hole expansion theory. The variation rules of soil displacement field, stress field and pile resistance around piles in the process of driving pile with enlarged wedge pile and equal section pile are compared and analyzed. The results show that the value of resistance at the end of pile is not only related to the cross-section area, but also to the value of pile tip resistance in the process of pile sinking. In the case of numerical model, the pile end resistance, pile side friction and integral pile sinking resistance are 1.81.1 and 1.5 times as much as that of the equal-section pile respectively in the case of the numerical model in this paper.
【作者单位】：河海大学岩土力学与堤坝工程教育部重点实验室;河海大学土木与交通学院;
【基金】：国家自然科学基金资助项目(51278170)
【分类号】：TU753.3

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