Temperature effect on static and quasi-static bridge measurements

The performance of bridge damage assessment based on model updating ap-proaches relies on correctly identifying the structural responses in the undamaged state. However, environmental uncertainties, such as temperature changes, influence structural responses in the same order of magnitude as damages. Therefore, a prestressed concrete bridge beam is studied in this paper. Temperature influences on static experiments in 2 test periods are minimized with physical temperature compensation technique. Displacement fluctuations decrease at least 60% after temperature compensation, making the summer and winter measurements comparable. Next, temperature-compensated Influence Lines (ILs), static flexibility and stiffness matrices are ob-tained. Comparing the results reveal the importance of performing measurements only on cloudy days. This paper contributes to differentiating between temperature effects and damages, which is crucial for a successful damage assessment.