考虑压实度的填土场基桩负摩阻力试验

填土场地会因处理手段和时间的差异呈现出不同的压实度，填土压实度的差异往往导致不同程度的沉降，并引起不同程度的基桩负摩阻力。针对不同压实度填土场开展基桩承载性状模型试验，研究不同压实度填土对基桩负摩阻力的影响；分析了不同填土压实度的加卸载与基桩沉降、桩端阻力之间的关系；研究了基桩轴力、桩侧摩阻力沿深度的分布情况以及随时间的变化关系，桩周土体随固结时间的沉降变化情况。试验结果表明：填土场基桩负摩阻力的发展演化存在明显的时间效应，与填土沉降先快后慢的趋势一致；随填土层压实度增加基桩负摩阻力减少，中性点位置上移。

Model tests on pile negative skin friction considering different filling compaction degree

Due to different ground treatment methods and consolidation time, the filling field has different foundation compaction that brings different settlements and various negative skin friction to piles. Based on the different filling compaction degree of landfill field, an experimental study on bearing capacity of foundation piles was carried out to study the influence of compaction degree on skin friction of foundation pile, including the relationships of compaction degree to pile top load, pile settlement, pile end resistance. The relations of pile axial force, pile side frictional resistance with depth and their time-varing characteristics were researched, and pile-adjacent soil settlement with consolidation time was obtained. The results showed that there was a significant time effect on the negative frictional resistance of the piles, and the change trend is consistent with the settlement of the filling,i.e, the fast in earlier period and slower in late period. With increase of compactness of the fill, the negative friction of the pile decrease, and the neutral point moves upward.