Effects of Temperature on the Static Response of Bridges: A Case Study

To ensure the long-term safety, durability, and performance of bridges, it is critical to account for the effects of thermal variations on structural behavior. Temperature changes induce volumetric expansions and contractions, which—when restrained—generate mechanical stresses that may compromise structural integrity. Accurately understanding and quantifying these thermal effects is especially important in the context of Structural Health Monitoring (SHM), where temperature-induced responses must be distinguished from other structural signals to avoid misinterpretation of the bridge's condition. Modern SHM systems incorporate advanced sensing technologies, such as thermocouples, fiber-optic sensors, and infrared imaging, to acquire real-time temperature data. These systems facilitate the analysis of thermal gradients, long-term temperature trends, and their relationship to mechanical responses. This study presents the design and initial findings of a static monitoring system implemented on an operational roadway bridge selected as a case study. The monitoring system provides continuous data on temperature-related structural behavior, supporting the identification of trends and potential anomalies. The bridge is instrumented with strain gauges, thermocouples, inclinometers, and displacement transducers. Based on the case study, the paper also explores different methodologies for monitoring and interpreting thermal effects by integrating temperature measurements with structural response data to evaluate their correlation.