Comparison of bridge topology before and after repair using attributed graph comparisons towards population based SHM

Population-Based Structural Health Monitoring (PBSHM) is a novel approach to overcoming the issue of limited data sets. Data-based SHM approaches have shown great promise in the ability to detect damage in structures; however, for bridges, there is often inadequate healthy and damaged state data for these methods to be applied. The PBSHM approach aims to assess similarity of structures in an effort to strengthen the data sets of individual structures within a population. This paper presents the first implementation of PBSHM to a suspension bridge, namely the Bosphorus Bridge. Refurbishment works of the bridge, completed in 2015, included the replacement of inclined hangers with vertical hangers. Two Irreducible Element Models are created for the bridge, before and after the repair works, and converted to Attributed Graphs before they are compared. The results of the comparisons are interrogated from an engineering perspective to check that they make sense, and accurately capture the changes, as well similarities, in the topologies of two states of the bridge.