Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Thermal effects in concrete bridges are loads that are capable of producing values of stresses that can be significant. Consequently, having good models to determine the results of these effects is of great importance. The presented thesis attempts to explain how temperature effects influence arch bridges. The objective is also to show a way of performing temperature compensation in these kinds of structures.
Traneberg Bridge is a concrete arch bridge built in 1934 that was submitted to a retrofitting procedure in which the original arch was kept. While the process was taking place, the structure was monitored with fibre optic sensors. Traneberg Bridge monitoring data is analysed and used as an example of how thermal compensation can be done.
A numerical model was used to determine the effects of temperature changes in an arch. The loads resulting from the retrofitting process were calculated, as well as the correspondent effect of referred loads in the structure. These effects were calculated using the influence lines of the arch. A finite element model was at the same time developed with the purpose of controlling the results, using the calculation software SAP2000.
Thermal compensation of the strains obtained by monitoring is made, and subsequent results are analysed and discussed. The presented thesis achieved results that can be considered satisfactory, when thinking about simplicity of the models used. Some stress variations measured could not be completely explained though, especially during the summer months.