Reliability of prestressed concrete girders design: Comparison between NBR and Eurocode codes

This work evaluates the reliability index of prestressed girders beams of highway bridges designed according to Brazilian and European codes concerning the bending ultimate limit state. A model was used to verify the resistant capacity of the beams in the bending ultimate limit state and to evaluate the live load models proposed by the regulations studied. The bridge studied spans 27.4 meters, and four T section prestressed concrete girders support it. To obtain the reliability index ????, the First Order Reliability Method (FORM) was used, which proved to be very fast and efficient. The values collected by the analytical method are validated using the Monte Carlo simulation method. For all cases, the reliability index value was higher than 5.5, showing that the two normative recommendations for the design of girders beams guarantee a very conservative level of safety.