坝陵河大桥深嵌岩桩竖向承载力试验

摘要

Based on the piled foundation testing of 2 deep rock-socked piles from Baling River Bridge of Guizhou Province and self-balanced testing technique, the vertical bearing capacity of piled foundation was tested and the testing results were discussed. The exertion of frictional resistance of pile side and resistance of pile tip of piled foundation of deep rock-socked pile, and the influential factors of them were analyzed. The study results indicate that load-displacement curve of large diameter and deep rock-socketed pile in this area becomes slowly declining. From the view of frictional resistance of pile side of rock, the value of ultimate side resistance which is provided by exploration report is less than the true one; with the point distribution of frictional resistance of pile side and tip resistance, the size which pile has embedded in sock has greater impact on the bearing capacity in the soft rock area, the rock-socketed ratio is greater, the corresponding bearing capacity is greater, and the deformation is smaller.%以贵州坝陵河大桥2根深嵌岩桩基为研究对象,利用自平衡测试技术检测了桩基的竖向承载力,对测试结果进行了讨论；分析了深嵌岩桩基的桩侧摩阻力、桩端阻力的发挥程度及其影响因素.研究结果表明:该地区大直径深嵌岩桩桩顶的荷载-位移曲线主要是以缓变型为主；从桩侧岩层摩阻力来看,勘探报告所提供的岩层极限侧摩阻力数值偏小；从桩侧摩阻力、桩端阻力分布来看,在软岩地区嵌岩深度大小对承载力影响较大,嵌岩比越大,则相应的承载力越大,变形越小.