3D simulation of masonry bridges under earthquake loading using an enhanced macroscale masonry model with embedded discontinuities

This paper investigates the 3D response of masonry arch bridges under earthquake loading, focusing on the interaction between the masonry components and the backfill under static and dynamic loading up to collapse. An advanced 3D modelling strategy is employed, in which masonry arches, piers, and spandrel walls are represented by an efficient continuum macroscale model that accurately captures masonry anisotropy through practical calibration of material parameters. Furthermore, zero-thickness plastic-damage interface elements are employed to simulate the interaction between masonry and backfill, which is modelled as a continuum elastoplastic frictional-cohesive material. Two realistic single and multi-span brick-masonry multi-ring arch bridges are investigated. Numerical predictions obtained by the proposed macroscale strategy are compared with detailed, yet more computationally expensive, mesoscale simulations. The results shed light on the complex response of masonry bridges under earthquake loading, confirming the accuracy of the developed macroscale modelling approach, which significantly reduces the computational cost while enabling detailed 3D nonlinear static and dynamic analysis of realistic bridges.