Interaction between Longitudinal Bending Moment and Transverse Shear Strength in RC Deck Slabs of Hollow Box Bridges

Due to the introduction of novel code provisions, the safety verification of existing structures and infrastructures has become a great issue. Analytical formulations based on sectional analysis are sometimes too conservative to optimize a strategy for intervention on existing structures, therefore non-linear finite element analyses are used to exploit the maximum overall capacity of the members under investigation. For example, membrane actions developing in continuous slabs or bridge decks can be considered by using finite element analyses able to take into account for mechanical and geometrical nonlinearity. In particular, this work deals with the interaction between longitudinal bending moment and transverse shear strength of a reinforced concrete (RC) existing hollow-box bridge built in Switzerland. In the perspective of Level of Approximation Approach proposed by the Model Code 2010, the shear strengths of a bridge deck have been calculated by adopting Model Code 2010 formulations, Critical Shear Crack Theory (CSCT) and Non-Linear finite element analyses. NLFEA have been carried out with the "PARC CL2.0 crack model" implemented in the ABAQUS program at the University of Parma, using a multi-layered shell modeling in order to predict global and local failures. This numerical investigation highlights that, even for design purposes, the interaction between longitudinal hogging moment and transverse shear strength may be significant in the assessment of the shear resistance leading sometimes to non-conservative predictions.