以中铁西安中心超高层建筑为工程背景，采用后压浆钻孔灌注桩技术对该工程进行地基处理。工程中测试钻孔灌注桩压浆前、后单桩竖向抗压静载试验及桩身内力。采用建筑桩基技术规范、侧阻、端阻分项增强系数法、基于极限承载力增强系数法和只考虑桩端改善承载力5种方法进行了后压浆桩的桩基极限承载力计算。结果表明，后压浆后桩基极限承载力提高了24%，侧阻、端阻分项增强系数法和基于极限承载力增强系数法与现场实测最接近；建筑桩基技术规范与只考虑桩端承载力改善与现场实测结果相差较大，其计算值偏于安全保守。

Based on the engineering background of a tall building at the center of Xi’an, the project uses the technology of post grouting bored pile foundation treatment. In construction, the vertical compressive static load with and without bored grouting pile; and pile body internal force are tested. This paper calculated the post-grouting pile's ultimate bearing capacity of pile foundation based on five methods, including the building pile foundation technical specification, lateral resistance and end resistance coefficient method, the ultimate bearing capacity enhancement coefficient method and improvement of the bearing capacity of pile. The results show that the ultimate bearing capacity of pile foundation increased by 24% with the methods of post-grouting pile; lateral resistance and end resistance coefficient method, and the ultimate bearing capacity enhancement coefficient method is closed to field measurement. Building pile foundation technical specification and the method of only considering the improvement of pile’s bearing capacity are largely different from the measured results, and the calculated value is conservative.