李芳著  苏振明
    （泉州市建设工程质量监督站 362000）

[提要] 根据福建泉州市区12个工程桩基的静载试验资料，初步分析了桩基工程经常出现质量事故的原因；指出该区多层建筑人工挖孔桩基础宜选择残（坡）积砂质粘土作为桩端持力层；对于此类桩的单桩极限承载力主要取决于受施工扰动“软化”程度及清孔情况影响的极限桩端阻力值，而增大桩端扩头直径和嵌入持力层深度对提高单桩极限承载力不起显著作用。
[关键词] 人工挖孔桩 静载试验 桩基质量事故 单桩极限承载力 极限桩端阻力

This paper gives preliminary analysis on the causes of pile foundations with serious quality problems according to the survey information of pile static load test of 12 projects in Quanzhou urban district. It is illuminated that risidual sandy clay (or talus) is a suitable bearing course for hand drilled pile foundation of multistoried buildings in this area, and the limit bearing capacity of single pile is mainly depended on the limit pile-tip resisting capacity interfered by the results of softened bearing course and pile-bottom cleaning, enlarging the pile-tip diameter and increasing the depth of socketed bearing course make less effect on the limit bearing capacity of single pile.
Keywords: hand-excavated pile, quality accident; pile foundation; static load test; limit bearing capacity of single pile; limit pile-tip resisting capacity