Stochastic Load-carrying Capacity Assessment of Brick Masonry Arch Bridges

Masonry arch bridges form an integral part of our infrastructure network, and their safety is important for the functioning of our society. Now, assessing the structural performance of ageing masonry infrastructure is a complex task. Existing ageing masonry arch bridges are characterized by inherent variability and may have stochastic material properties even in the same bridge. Hence, a realistic methodology for structural assessment of masonry arch bridges is crucial to protect the ageing masonry bridges and utilize these resources efficiently. In this study, stochastic assessment on the load-carrying capacity of masonry arch bridges has been performed, including material variabilities into a two-dimensional structural analysis model based on the Discrete Element Method (DEM). Over 100 probabilistic analyses have been developed to assess the ultimate load that a bridge can carry when subjected to monotonic loading at a quarter span. The bond properties of mortar joints, including cohesion, tensile strength, and friction angle, were considered as stochastic variables following a normal distribution. The computational results were compared against the experimental results obtained from the literature. From the results analysis, it was shown that the computational model considering the random variability of bond strength properties can better predict the load-carrying capacity of the masonry arch bridge than the deterministic one. The bond strength at the unit-to-mortar interface significantly affected the ultimate strength of the masonry arch bridge.