MONOLITHIC CONNECTION OF THE DECK SLAB TO THE ABUTMENTS FOR THE IMPROVEMENT OF EARTHQUAKE RESISTANCE IN MULTI-SPAN CONCRETE BRIDGES

The locally separated deck slab continuity concept as presented here helps to avoid complicated construction and earthquake design and may even result in some savings below conventional jointed construction due to simplifications in detailing and drainage arrangements at these locations. The design of the continuous concrete deck slab, which is monolithically connected to both abutments and undergoes alternate thermal actions, is generally such that the tensile stresses will induce cracking which should comply with Code requirements. It therefore follows that should restraint advantage from the connecting slab be desired to be considered in the global analysis of the main deck, cracked and untracked stiffness should be used in the model of thermal actions effect. The thickness and reinforcing of connecting of two abutments continuous slab will normally depend on temperature differences, structural configuration, live loads, stiffness of bearing, skew and method of articulating the bridge. Fatigue in reinforcement due to stress reversals should also be designed by compliance with Code requirements, as for the rest of the deck slab. Finally, preliminary calculations indicate that a theoretically unlimited number of spans could be made continuous using this approach. This paper deals with the design of composite reinforced/pre-stressed concrete bridges with continuous deck slab, which is integrally connected to the abutments. The implementation of the continuity technique is investigated in order to improve the earthquake resistance and robustness of the structure (bridge).