Reliability-based assessment of masonry arch bridges

The paper presents a methodology for the probabilistic assessment of masonry arches at the serviceability and Ultimate Limit States. First, it explains the definition of the different failure modes and corresponding limit state functions that may occur depending on the type of masonry construction (single-ring and multi-ring). The most reported modes of failure are the four-hinge mechanism, the ring separation in multi-ring arches and the slippage at the foundations. Because of the lack of reliable material data (in the statistic sense) or available response models, only those more prone to be analyzed using reliability-based methods are shown in this paper: four-hinge mechanism and ring separation.The possibility of fatigue failure of masonry arch bridges under service loads and the proposal of reliability-based assessment methods at the ultimate level of the four-hinge mechanism are also analyzed. Finally, the proposed methodology is applied to an existing bridge.