Studies on Design Parameter and Fatigue Performance of a New Type of Orthotropic Steel Bridge Deck

Abstract

The rib-to-deck and the rib-to-diaphragm details are the weak position of fatigue problem of conventional orthotropic steel bridge decks (OBDs). To improve the fatigue performance at such fatigue details, a new type of OBDs structure with semi-open longitudinal ribs was proposed. This new structure can not only realize full penetration welding between the deck and longitudinal rib, but also reduce the stiffness difference between the longitudinal rib and the diaphragm. The structural parameters of the new structure were analyzed, and the reasonable values of each structural detail of the new bridge deck were given. The lateral and longitudinal stress influence lines of different structural details in the new and conventional steel bridge deck were comparatively studied. And the results show that the stress on the deck of the rib-to-deck in this new type of OBDs is larger, but full penetration welding can effectively improve the welding quality of the rib-to-deck joint, thus ameliorate the eccentric force of the single fillet welds. The change in longitudinal ribs weakened the stress concentration at the rib-to-deck, and improved its fatigue properties.