混凝土支撑在深基坑支护系统中应用十分广泛，在基坑施工监测中常综合支撑轴力变化情况判断基坑稳定性，但诸多原因导致了支撑实测轴力和设计轴力存在较大的差异。根据苏州轨道交通一号线广济路站基坑混凝土支撑轴力监测数据，综合基坑的围护形式、开挖形式和实时工况，对混凝土支撑轴力监测计算结果进行了详细的分析，总结了影响实测轴力变化较大的主要因素，提出了混凝土支撑轴力计算的优化建议。

Concrete bracing is widely used in the support system of deep foundation pits. During the construction monitoring of foundation pits, the change of the axial force of the bracing is usually used to evaluate the stability of the foundation pits. However, there are many factors that cause differences between the measured axial force and the designed axial force. On basis of the monitoring of the axial force of the concrete bracing of the foundation pit of Guangji station on No. 1 Line of Suzhou Metro, the retaining structure excavation method and insitu construction situations, the author analyzes the monitoring results of the axial force of the concrete bracing in detail, summarizes the main factors that cause dramatic changes of the measured values and makes suggestions on the optimizing of the calculation of the axial force of the concrete bracing.