Reusability diagnosis method for demolished bridge girders based on topological evolution of load paths

Abstract

In this study, a reusability diagnosis method for demolished bridge girders is proposed by evaluating their damage state and future reuse environment. A modified strut-and-tie model (STM) is first established by considering the topological evolution of load paths. Limit failure criteria of the modified STM are given to predict the bearing capacity of demolished bridge girders. Subsequently, classification criteria for damage state and reuse environment are developed based on the bearing capacity and exposure levels during reuse, forming a decision matrix for diagnosing reusability. Finally, the applicability and effectiveness of the reusability diagnosis method are demonstrated through case studies of demolished structures. Results show that the configurations of load paths vary with the increase of shear span-depth ratios. The modified STM can accurately evaluate the bearing capacity, improving the accuracy of damage state assessments and reducing subjectivity in diagnosing reusability.