Numerical analysis on redundancy of continuous twin I-girder steel concrete composite bridges

Redundancy is one of the most important factors to evaluate the safety of a bridge as it shows the possibility of the bridge to survive after an incident that can cause partial or full damage on the critical member of the bridge. The purpose of the present study is to evaluate redundancy level of three span continuous twin I-girder composite bridges, which is widely used in current highway bridges. Bridge models were studied and analyzed by using the finite element method with the aid of DIANA Software. Firstly, experimental results were used to verify the validity the present numerical model. Thereafter, fracture of one mid-span girder was assumed in order to determine the redundancy level of damaged bridge models. This study also shows the importance of secondary members in transferring and redistributing the load after the fracture at the mid-span of one main girder of the bridge.