几种缺陷单桩竖向承载性状的现场模型试验研究

发布时间：2018-04-26 14:12

本文选题：灌注桩 + 缺陷桩　；参考：《岩土力学》2014年11期

【摘要】：为评价灌注桩在施工过程中因形成缩径、扩径、断桩、泥皮等缺陷导致单桩竖向极限承载力变化的程度,针对缺陷桩单桩开展了现场模型试验研究。进行正常桩和缺陷桩的竖向静载模型试验,测试单桩竖向极限承载力,对比缺陷桩和正常桩的单桩承载特性,分析了缩径、扩径、断桩、泥皮等缺陷对单桩承载性状的影响。对比正常桩和缺陷桩的荷载-沉降关系曲线,得出了基于文中缺陷桩设计方案的结论,缩径缺陷和泥皮缺陷均使单桩竖向极限承载力降低,降幅在正常桩极限承载力的15%范围内;扩径缺陷桩的荷载-沉降关系曲线无明显陡降点,桩顶沉降较正常桩递增缓慢;断桩缺陷影响荷载-沉降关系曲线中反弯点的出现位置,即反弯点出现时的桩顶位移与断桩缺陷距地表的距离有关。
[Abstract]:In order to evaluate the change degree of vertical ultimate bearing capacity of single pile caused by defects such as shrinkage, expansion, broken pile and mud skin in the construction process, field model test research was carried out for single pile with defect. The vertical static load model test of normal pile and defective pile was carried out, the ultimate bearing capacity of single pile was tested, the bearing characteristics of single pile with defect pile and normal pile were compared, and the influence of shrinkage, diameter expansion, broken pile and mud skin on the bearing behavior of single pile was analyzed. Compared with the load-settlement curves of normal pile and defective pile, the conclusion based on the design scheme of defective pile in this paper is that the vertical ultimate bearing capacity of single pile is reduced by shrinkage defect and mud skin defect. The decrease is in the range of 15% of the ultimate bearing capacity of normal pile, the curve of load-settlement relationship of expanded defect pile has no obvious and steep drop point, the settlement of pile top is increasing slowly than that of normal pile, and the defect of broken pile affects the position of reverse bending point in the curve of load-settlement relationship, That is, the displacement of pile top when the reverse bending point appears is related to the distance between the broken pile defect and the ground surface.
【作者单位】：天津大学建筑工程学院;
【基金】：国家自然科学基金(No.50978182)
【分类号】：TU473.11

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