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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6. Effect of temperature on the deformation of the footbridge Since 2012, precise levelling has been carried out on the footbridge at regular intervals. During the levelling process, the air and the superstructure (average value from 6 locations) temperatures were measured. The deflections of the footbridge were recorded against the reference measurement from 9/2012. The differences in the temperature relative to September 2012 were modelled as non-linear combinations. The resulting bridge deformations are shown in the graph below, see Fig. 4, the extreme sensitivity to temperature and high deformations are evident. The difference between the measured values from the levelling and the calculated values on the undamaged model is shown in the graph below. The graph shows a slight regression relationship indicating a gradual increase in the deflection of the fields over time after temperature adjustment, which can be interpreted as the effect of corrosion and cable damage, however, affected by the uncertainty of the superstructure temperature measurement, see Fig. 5.

Fig. 4 Calculated deformations from the uniform temperature change of the footbridge structure at the time of the levelling

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Fig. 5 (a) Difference between measured and calculated deflection values of the spans, (b) irreversible deformation due to corrosion damage of the main and prestressing cables against the model without damage

As can be seen, the significant corrosion damage results in deformations of approximately 20-30 mm. However, it should also be noted that the deformation of the footbridge caused by corrosion of the prestressing cables is about 7 times smaller than the normal deformation due to temperature.