Abstract: By analyzing and introducing the current situation and the problems in data analysis of bridge health monitoring， a null point identification method of live load for bridge structure based on the long-term monitoring data was proposed． The time from 2: 00 to 4: 00 in every morning was set as the data screening period，and the null points of live load were taken when the stress of the roof and floor were both minimum． By determining a null point of live load as the reference state daily， and the obtained point was taken as referential point to deal with the monitoring data daily． The proposed method greatly reduces the impact of the cumulative error and the uncertainty of temperature on the processing of monitoring data．

Key words: continuous rigid frame bridge, null point of live load, measured data, temperature

摘要： 通过分析介绍桥梁健康监测中数据分析的现状及存在的问题，提出了一种基于长期监测数据的桥梁结构“零 活载点”识别的原理及其方法，给出了具体的识别过程及判断条件。根据实桥桥梁监测数据的规律，设定每天凌晨 2:00—4:00作为“零活载点”识别的数据筛选时间段，取顶、底板应力同为最小时刻作为零活载点。通过每天确定 一个零活载点作为基准状态，以此为参照点来处理每天的监测数据，大大减少了系统累积误差及温度等不确定因素 对于监测数据处理的影响。

关键词: 连续刚构桥, 零活载点, 监测数据, 温度