REAL-TIME SEPERATION OF TEMPERATURE EFFECT ON DYNAMIC STRAIN MONITORING AND MOVING LOAD IDENTIFICATION OF BRIDGE STRUCTURE

Strain monitoring is an important content of health monitoring and condition assessment for a bridge structure. However, in practical engineering application, the value of strain monitoring is usually affected greatly by temperature, so that it is not able to distinguish the strain monitoring value caused by a moving load from the total measured strain, which lead to the loss of efficacy of a pre-established early-warning index. Based on the monitoring results of strain and temperature of a cable-stayed bridge in Hefei, an engineering method for the real-time separating temperature effect from strain monitoring is derived. First, the temperature distribution in the girder of the bridge has been analyzed, and a suggestion for temperature sensors distribution is put forward. Then, according to the analysis of the monitoring value of strain, the temperature effect value is obtained by the time-varying average value method. The simple and efficient method can be applied to the real-time temperature correction of monitoring data and the setting of dynamic early-warning index in an online bridge structure health monitoring system. The residual strains of different locations can be used to identify the moving load of a bridge structure.