Mechanical Property Evolution and Load Monitoring Method of Laminated Elastomeric Bridge Bearings Under Temperature Effects

The mechanical behavior of laminated elastomeric bearings in service is highly sensitive to ambient temperature, whereas conventional monitoring approaches often fail to accurately capture their temperature-dependent load response. To address this issue, this study proposes a multi-temperature framework for identification and load monitoring of bridge elastomeric bearings. Using a high-precision laser displacement measurement system, six temperature levels were defined from −20 to 30 °C at 10 °C intervals. Room-temperature load–displacement calibration tests, compressive elastic modulus tests under different temperature conditions, and monitoring accuracy validation tests were then systematically conducted. Based on these experiments, the effects of temperature on the mechanical properties and compressive deformation response of the bearing were quantified, and an inverse load-identification model was developed. The results show that the compressive elastic modulus increases markedly with decreasing temperature, reaching a 32.11% increase at −20 °C relative to that at 30 °C. Under the same applied load, the vertical compressive deformation decreases significantly as temperature decreases, with a 27.76% reduction at −20 °C compared with that at 30 °C, indicating a pronounced low-temperature stiffening effect. The proposed inverse load-identification model achieves a maximum relative error of 4.83% over the full temperature range, demonstrating good accuracy and applicability. The proposed methodology provides a practical basis for mechanical-performance evaluation and high-precision monitoring of bridge bearings under complex thermal environments.