PSI - Issue 64

Pavel Ryjáček et al. / Procedia Structural Integrity 64 (2024) 228 – 237 Pavel Ryjacek / Structural Integrity Procedia 00 (2019) 000 – 000

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This paper focuses purely on the dynamic behaviour of the bridge and its results, with the respect to the possible damage detection. The paper is not covering all diagnostics works done on the bridge, that were showing symptoms of the future problems.

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Fig. 1. Footbridge cross section, after the partial renovation (a) and collapsed bridge (b)

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Fig. 2. The segment 36 and 37, location of the bridge failure, significant corrosion – many cables were totally corroded (a) and caverns between the cables (b) 2. Analysis of the documents and the remains of the footbridge In the first phase, a detailed analysis of the bridge documents was carried out with regard to geometric and material properties, but also with regard to the condition of the footbridge and the development of damages. The results of the geodetic survey, the results of long-term monitoring and static and dynamic measurements were analysed. In order to specify the fundamental input, the modulus of elasticity of the concrete, a test was done - the average value was E=32.7 GPa, standard deviation was 5,1 GPa. Based on the analysis, a list of possible defects further was analysed by numerical models. These are: • caverns in the Alfa cables overlay, see Fig. 2b • corrosion of the Alfa cables, see Fig. 2a • ungrouted Beta cable ducts and corrosion of Beta cables, • the change in the temperature of the structure, the effect of the railing stiffness, • the change of bearing stiffness and their blocking, or bridge getting to the contact with bearings, • the effect of uneven settlement of the pillars.