花岗岩残积土地基钻（冲）孔灌注桩竖向承载力研究

通过对花岗岩残积土地基的特殊性及其钻（冲）孔灌注桩单桩竖向承载力试验研究的综合分析，剖析了花岗岩残积土地基桩端阻力和桩侧阻力特性和现有计算方法存在的问题。通过分析砾、砂、黏质花岗岩残积土天然地基承载力基于标准贯入击数相关性的修正系数，提出了桩端阻力、桩侧阻力与按标准贯入击数修正的桩基规范液性指数法计算结果的经验关系，可供按JGJ 94-2008《建筑桩基技术规范》中经验公式计算花岗岩残积土地基钻（冲）孔灌注桩单桩竖向承载力时修正参考。与工程试桩的实测数据对比结果表明，文中建议的计算方法稍偏于安全，且比JGJ 94-2008《建筑桩基技术规范》中方法更接近实测值。

Pile vertical bearing capacity of bored pile in granite residual soil

Single pile bearing capacity in granite residual soil was studied considering the particularity of the granite residual soil and in-situ test results of bored piles in granite residual soil. Based on the analysis of characteristic of end resistance and shaft resistance of bored piles in granite residual soil, the existing problems in current calculation method of end resistance and shaft resistance of bored piles in granite residual soil were discussed respectively. Through analysis of positive correlation correction coefficient of natural foundation bearing capacity of gravally, sandy and clayey granite residual soil, where the standard penetration number considered, the empirical relationship between the blow of standard penetration test and end resistance and shaft resistance of bored piles in granite residual soil is put forward, whose correction has been made under current Chinese standard JGJ 94—2008 ‘Technical code for building pile foundation’ of pile foundations that only considers the liquidity index. Through the comparison with the test data, it is shown that the calculated value from the suggested method in this paper is on the safe side and closer to the measured values than method in standard JGJ 94—2008.