Strain-temperature correlation analysis of a tied arch bridge using monitoring data

For the reliable assessment of bridge health and safety conditions, it is important to distinguish the abnormal changes of bridge structural responses caused by structural damage from the normal changes due to environmental fluctuations. This paper addresses the modeling of separating temperature effect from structural strain responses of a tied arch bridge in China. The bridge has been instrumented with a long-term structural health monitoring system since 2007. One-year measurement data obtained from the strain and temperature sensors are used for this study. The correlation analysis technique is applied to quantify the effect of temperature on the strain responses. The results show that the linear regression model exhibits good capabilities for mapping the strain responses with temperature. Using this model, the temperature effect can be separated from the overall responses. The variation of the model parameters (variation rate and intercept) and the residual responses after removing the temperature effect can be used for novelty detection and overload alarming.