ABSTRACT
The art of designing and building bridges has evolved gradually. In early bridges, a non-composite slab and beam system was frequently used where the slab provided the riding surface, and the beams supported dead and live loads transmitted from the slab. For this non-composite system, force responses in the slab and the beams are very simple and easy to calculate. Composite design followed once the interactions between various bridge components was sufficiently understood. The main advantage of the composite system is the increased load carrying capacity due to the load sharing mechanism developed from its composite action. However, in this case, the stress responses and their distributions and redistributions at ultimate limit state become much more complicated. With increasing complexity of geometry and combination of different materials in bridge construction, the analysis of such structures becomes a very complex undertaking. In this case simplified analytical methods, such as equivalent beam theory, are not adequate. A refined analysis method which is capable of representing all structural responses and deformations must be used.
