A novel attached-spring model for damage quantification and degradation evaluation of short/mid-span bridges

Short/mid-span bridges are the most commonly used infrastructure in highways, railways, and other transportation projects. With service time increasing, local damage and performance degradation of short/mid-span bridges are inevitable. Therefore, the assessment of the bridge condition is essential to ensure its safe operation. However, the existing methods mostly assume the damage region of the bridge as a uniform reduction in stiffness, which is not consistent with the actual bridge. Consequently, those methods can hardly achieve the evaluation of the damage. To address this issue, this paper proposes a novel attached-spring model for damage quantification and degradation evaluation of short/mid-span bridges. By assuming the damage region as a spring, an attached-spring model is proposed to describe the nonuniform local damage of the bridge. Then, the deflection influence line is used to identify the stiffness and position of the attached-spring, which achieves the damage detection and evaluation. This approach provides a general model to describe various bridge damage and evaluate the effect of the damage. Numerical simulation and experimental tests are used to verify the feasibility and accuracy of the proposed method. By comparing the results identified from the moving load test and those measured from the static test, the performance of the method is assessed.