厚填土区成桩质量对竖向荷载传递性状的影响  

Influence of quality of pile construction on load transfer properties in deep sandstone filling soil area

作　　者：黄挺[1,2] 陈喜强 崔伟[1] 欧孝夺[1] 

机构地区：[1]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004 [2]南宁市城市建设投资发展总公司,广西南宁530031 [3]中港四航局第一工程公司,广东广州510500

出　　处：《广西大学学报（自然科学版）》2009年第5期587-593,共7页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(40772190);工程防灾与结构安全教育部重点实验室主任基金资助课题(2009TMZR005)

摘　　要：结合广西钦州港大型炼油项目装置区桩基试验工程,开展砂岩厚填土区单桩竖向静载试验及桩身内力试验研究,通过对2根冲孔灌注桩的孔径曲线、Q-s曲线及桩身内力分布曲线的研究,探讨了桩径变化对于砂岩厚填土区嵌砂岩短桩的承载力性状及荷载传递规律的影响。结果表明,对于砂岩厚填土区后压浆嵌岩桩,其变形特征为缓变型,其极限承载力的确定以位移控制,桩身轴力与桩径的变化密切相关,孔径随深度呈逐渐增大的"正八字形"的孔径变化不利于桩侧摩阻力的发挥,而"倒八字形"的孔径变化则有利于桩身荷载向桩周土中传递,60%以上的桩顶荷载由桩侧摩阻力承担,最后对2根试桩的桩侧摩阻力发挥程度进行了差异性分析。研究对类似地区桩基设计与施工具有参考价值。The vertical static loading and internal force tests of the piles used in the pile foundation experiment in the area of the giant refinery project in Guangxi Qinzhou Port were carried out. By researching the curves of pile diameter, Q-s curves and the internal force curves of two impact-cone concrete piles, the influence of varying pile diameter on the bearing capacity and load transfer mechanism of the rock embedded short pile with post-grouting technology in deep sandstone filling soil area were discussed in the paper. The results showed that for the pile, there is no obvious failure feature and its ultimate bearing capacity is determined by the displacement. The axial force of the pile changes with the pile diameter closely. When pile diameter was gradually increased with depth, looking like a ＂splayed configuration＂, it is not conducive to the lateral friction of piles, while a reversed ＂splayed configuration＂ change of the pile diameter benefits the transmission of pile loading in the soil. It is easy to cause negative friction near pile tip, and 60% of the load on pile top was endured by pile side friction resistance. The test results can be used in design and construction of the piles in similar place.

关 键 词：砂岩厚填土 冲孔灌注桩 嵌岩桩 桩径变化 荷载传递性状 

分 类 号：TU473.11[建筑科学—结构工程]