【摘要】 现有的钻孔灌注桩设计方法未考虑施工效应和桩端沉渣对侧阻力的影响。依托黄河下游地区某铁路桥梁工程的2根大直径组合压浆灌注桩自平衡静载试验，研究了组合压浆前后施工效应和桩端沉渣对大直径钻孔灌注桩侧阻力弱化效应的影响。现场试验结果表明：施工效应和桩端沉渣会造成大直径钻孔灌注桩侧阻力弱化，桩端沉渣越厚则侧阻力弱化效应越严重，而组合压浆可以减弱这类侧阻力弱化效应并提升侧阻力的调动速度，改善大直径桩的端阻力和承载力。研究成果为合理修正传统桩基承载力计算方法，优化桩基设计和提升桩基承载力提供一定参考。更多还原

【Abstract】 The existing design method of bored pile does not consider the construction effect and the influence of pile tip sediment on lateral resistance. Based on the self balanced static load test of two large-diameter composite grouting piles for a railway bridge project in the lower reaches of the Yellow River, the construction effect before and after composite grouting and the influence of pile tip sediment on the side resistance weakening effect of large-diameter bored piles were studied. The field test results showed that the construction effect and pile-end sediment weakened the shaft resistance of large-diameter bored piles. The thicker the pile-end sediment was, the more serious the weakening effect of shaft resistance was. The combined grouting weakened the weakening effect of shaft resistance and increase the mobilization speed of shaft resistance, improving the end resistance and bearing capacity of large-diameter piles.更多还原