基于目前国内外理论计算方法及其存在的问题，结合湿陷性黄土的特点，对柱锤冲扩桩法的加固机制进行进一步的分析。首先运用弹塑性力学和圆孔扩张理论，对柱锤冲扩桩法复合地基承载力进行推导；然后结合具体现场工程实例，采用静载荷试验测得复合地基承载力，动力触探检验加固效果和加固深度； 最后将推导结果与规范、实测数据进行对比，证明该公式的计算结果与静载荷试验的实测值较为接近，地基承载力和加固深度能够满足设计要求。

In the paper, the mechanisms of the consolidation of collapsible loess by means of column hammer pile method are analyzed on basis of the calculation methods at home and abroad. First, the loadbearing capacity of the composite ground consolidated by column hammer pile method is derived by means of elasticplastic mechanics and cylindrical cavity expansion theory; Then, the loadbearing capacity of the composite ground consolidated by column hammer pile method is measured by means of static load test and the consolidation effect and consolidation depth are verified by means of dynamic penetration test, with a case history as background; Finally, the calculation results are compared to the values specified in relevant standards and the values measured, which shows that the calculation results agree well with the results measured by static load test and that the loadbearing capacity and the consolidation depth of the composite ground can meet the design requirements. The paper can provide reference for the application of column hammer pile method in collapse loess in the future. 