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Identifying damage in a bridge by analysing rotation response to a moving load

2019-11-04, Hester, David, Brownjohn, J. M. W., Huseynov, Farhad, O'Brien, Eugene J., González, Arturo, Casero, Miguel

This article proposes a bridge damage detection method using direct rotation measurements. Initially, numerical analyses are carried out on a one-dimensional (1D) simply supported beam model loaded with a single moving point load to investigate the sensitivity of rotation as a main parameter for damage identification. As a result of this study, the difference in rotation measurements due to a single moving point load obtained for healthy and damaged states is proposed as a damage indicator. A relatively simple laboratory experiment is conducted on a 3-m long simply supported beam structure to validate the results obtained from the numerical analysis. The case of multi-axle vehicles is investigated through numerical analyses of a 1D bridge model and a theoretical basis for damage detection is presented. Finally, a sophisticated 3D dynamic finite element model of a 20-m long simply supported bridge structure is developed by an independent team of researchers and used to test the robustness of the proposed damage detection methodology in a series of blind tests. Rotations from an extensive range of damage scenarios were provided to the main team who applied their methods without prior knowledge of the extent or location of the damage. Results from the blind test simulations demonstrate that the proposed methodology provides a reasonable indication of the bridge condition for all test scenarios.

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Publication

Analysis of Load Test on Composite I-Girder Bridge

2016-05-27, Huseynov, Farhad, Brownjohn, J. M. W., O'Brien, Eugene J., Hester, David

This paper showcases the importance of field testing in efforts to deal with the deteriorating infrastructure. It demonstrates a load test performed on a healthy but aging composite reinforced concrete bridges in Exeter, UK. The bridge girders were instrumented with strain transducers and static strains were recorded while a four-axle, 32 tonne lorry remained stationary in a single lane. The results obtained from the field test were used to calculate transverse load distribution factors (DFs) of the deck structure for each loading case. Additionally, a 3-D finite element model of the bridge was developed and calibrated based on field test data. Similar loading cases were simulated on the analytical model and behaviour of the structure under static loading was studied. It was concluded that the bridge support conditions had changed throughout its service life, which affected the superstructure load distribution characteristics. Finally, DFs obtained from analysis were compared with factors provided in Design Manual for Roads and Bridges Standard Specification for similar type of bridges.