ABSTRACT
The paper focuses on the numerical analysis of strengthening solutions dedicated to masonry arch bridges. It concentrates on the longitudinal behaviour of the arch of single-span bridges. The analysed methods are related to the addition of specific structural components on both sides of the arch – extrados and intrados. Two basic solutions are studied based on a rigid or flexible layer corresponding to the most common techniques being applied to these bridges around the world. A comparison of the selected strengthening techniques is given considering their impact on the bridge’s structural behaviour under incremental static loadings. Particular attention is paid to the analysis of the progressive failure being developed along with the increasing load. For this purpose, an advanced nonlinear Finite Element models using a meso-modelling technique are presented and selected results showing the mechanical performance of the structure before and after strengthening are provided. The interpretation of the bridge model response is based on the analysis of the evolution of the structural failure modes up to the maximum load capacity of the bridges, namely in terms of the interaction of internal forces M-N in representative arch cross-sections determined also analytically. Conclusions are formulated to identify optimum reinforcement solutions regarding both the sectional as well as the global performance of the structures.
