Research on the influence laws of traffic and temperature loads on the strain responses of urban girder bridges

• Discussing the distribution characteristics of the temperature field in urban beam bridge structures. • Investiagating the influence laws of traffic and temperature loads on the strain responses of urban girder bridges. • Defining the concept of strain ratio angle and discussing the influence laws of traffic and temperature loads on this parameter. Accurately determining the influence laws of traffic and environmental temperature loads on bridge structural responses has long been a challenge in bridge health monitoring. To address this issue, a three-span continuous girder bridge located in an urban area was selected as the study object. By utilizing strain monitoring data affected solely by environmental temperature and strain monitoring data influenced by both traffic loads and environmental temperature, the influence laws of traffic and temperature loads on the strain response of urban girder bridges were investigated. First, the distribution and variation laws of the temperature field of the bridge were analyzed, and then the variation laws of the strain monitoring data under the influence of traffic and temperature loads were studied. Concurrently, the changes in the strain ratio angle under the influence of traffic and temperature loads were investigated via correlation analysis. Through the aforementioned research and analysis, the results provide insights and references for further studying the influence laws of traffic and temperature loads on other responses of urban girder bridges, as well as for developing bridge condition diagnosis methods, excluding the interference of environmental factors and traffic loads.