Damage identification method for tied arch bridge suspender based on quasi-static displacement influence line

Abstract

Preventive measures must be implemented to preclude severe damage to bridge structures and thus avoid catastrophic accidents. A potential method for bridge damage identification is the characterization of structures through influence lines. However, influence line detection studies related to arch bridge damage are not sufficiently comprehensive. In this paper, a displacement difference influence line damage detection method for tied-arch bridge hangers is proposed. First, based on the structural characteristics of the arch bridge hanger, an elastic support beam model assumption is developed. Then, the relationship between local damage and extent of damage (DE) to the arch bridge hanger based on the displacement influence line is established through analytical derivation. Subsequently, the influence of hanger damage location and DE was analyzed using the MIDAS software finite element model. A reasonable vehicle loading test scheme is also proposed. The influence of factors, such as load spacing, loading path, measurement location, axle load mode and noise error, on identifying the damage to arch bridge hangers is examined by controlling a single variable and conducting a comparative study. Finally, the sensitivity of arch bridge component damage to hanger damage is investigated through finite element verification and gray correlation analysis. Hence, the proposed detection method is found capable of identifying local structural damage to arch bridge hangers.