Bridge deck analysis through the use of grillage models

The object of the paper is the study of the representativity of the grillage models with which different types of bridge decks are schematized. First, the theoretical principles on which this kind of modelling is based are recalled; the equivalent condition between bi-dimensional continuous elements and corresponding grillage models are imposed through the use of a kinematics and an energetic criterion. Secondly, the same technique is generalized to three-dimensional structures and specialized to the case of cellular decks. For this kind of deck, structural behaviours usually neglected by the current technical approaches, like shear lag, distortion and warping, are considered. The paper presents some methods introducing these effects in a grillage analysis; these methods provide a series of criteria with which it's possible to define the rigidities of the equivalent model. These criteria are applied and compared with finite element solutions. Finally, a series of applications are executed in order to verify the efficiency and the accuracy of this kind of approach.