Valores frecuentes y característicos de la acción de tráfico sobre los puentes de carretera. Comparación con los valores de la IAP-98 y EC-1

Frequent and characteristic values of traffic action on spanish highway bridges. Comparison with Spanish (IAP-98) and European (EC-1) standards

The paper presents a comparison between the traffic action (characteristic and frequent values) in highway bridges as deduced from the Eurocode 1. Part 3 and the Spanish Code IMP-98, with the values coming from a model of traffic simulation and with two volumes of traffic representative of heavy (Average Daily Truck Traffic = 6000) and light (ADTT = 1500) traffic conditions. The study focuses on the bending moment bridges with two-lane in one direction. The analysis carried out takes into account the two dimensional behaviour of the deck using a grillage method. A total of 8 different bridge decks are analysed. They are fully representative of the new bridges in the existing Spanish network. Span length ranges from 22 up to 150 m and the longitudinal layout corresponds to simply supported and continuos bridges. The cross-section types cover I-girder prestressed beams, slabs and box-girder. As a conclusion of the results obtained several correction factors are proposed in order to obtain the best estimate of the longitudinal bending moments due to traffic (characteristic and frequent values) starting from the proposed values in Eurocode EC-l.