基坑混凝土支撑轴力监测数据异常情况分析与探讨

Analysis and Discussion of Monitoring Data Anomaly of Axial Force for Concrete Support of Foundation Pit

为研究混凝土支撑轴力监测数据中出现的异常情况,探讨其解决方法,依托正处于主体结构开挖阶段的武汉市轨道交通8号线徐家棚站,深入分析施工过程中发生的一次混凝土支撑轴力监测数据报警事件,研究监测报警数据的合理性,结合其他监测项目并与类似工程案例对比,得到:1)建议选取混凝土浇筑并养护完毕、基坑开挖之前的轴力值作为初始应力值;2)温度对轴力有较大影响,应结合其他监测项目协同分析;3)目前采用钢筋计进行混凝土支撑轴力监测的方法在准确度上还有所欠缺。结合分析,给出了应对措施和建议。

The analysis and discussion are made on monitoring data anomaly of axial force for concrete support of Xujiapeng Station on Line No.8 of Wuhan Railway Transit.The rationality of monitoring data alarming is studied;comparison among similar projects is made;and some countermeasures are discussed.Some conclusions are drawn as follows：1）The axial force of concrete support measured after concrete casting and curing and before foundation pit excavation should be taken as initial value.2）The temperature affects the axial force obviously.3）The precision of reinforced bar gauge used for concrete support axial force monitoring is not good.Finally,some countermeasures and suggestions are given.