滇西山区大直径灌注桩承载性能试验研究

【作者】 仇玉良；

【导师】 谢永利；

【作者基本信息】 长安大学 ， 岩土工程， 2002， 硕士

【摘要】 本文针对滇西山区大直径灌注桩竖向承载力确定存在的问题，进行了5根试桩的静载荷试验，分析了区域地质条件下土的物理、力学性质的变化对桥梁桩基承载力的影响程度；地下水对桩承载力的影响程度；各种外部因素影响下，桩的施工工艺对桩承载力的影响程度；通过在桩体周围土中注浆对桩承载力的影响程度。得出一些有价值的结论：人工挖孔灌注桩的极限承载力明显高于钻孔灌注桩的极限承载力；地下水位对桩基承载力有显著影响；利用桩侧注浆可有效提高桩的承载力；桩侧摩阻力所占总荷载的比例远大于桩底压力，桩侧土的摩阻强度平均值为30～50KPa。论文建议滇西山区沟谷地段桩基竖向承载力设计使用采用分项安全系数的经验公式，并初步给出了各参数的取值范围。更多还原

【Abstract】 Directed against the problem on confirming vertical bearing capacity of large diameter cast-in-place pile in the west of coteau area of Yunnan province, the paper, analyses the influence degree of the variety of soil physics and mechanics property in area geology condition on bearing capacity of pile foundation, through 5 piles’ loading test; the influence degree of construction technics on bearing capacity of pile foundation under the influence of every exterior factors; the influence degree of grouting injection around the pile shaft on bearing capacity of pile foundation. The paper draws some valuable conclusions: the limited bearing capacity of manual excavation filling pile is much higher than the limited bearing capacity of machine drilled filling pile; Through grouting injection around the pile shaft, the pile bearing capacity can be effectively improved; Proportion of resistance force around the pile side in total load is much larger than that of pressure on the pile tip, and the intensity of resistance force around the pile side is 30-50KPa on average. The paper also advise that the design of pile vertical bearing capacity in the west of coteau area of Yunnan province taking advantage of the experience formula which adopt subentry safety factors, and come up with the value range of the parameters preliminarily.更多还原