Numerical modelling of three-dimensional masonry arch bridge structures

Abstract

A substantial part of the underline bridges that belong to the asset collection of the main railway and roadway infrastructure operators in the UK and Europe have the structural shape of arches, typically constructed from brick/stone masonry. Current assessment methods, which consider two-dimensional descriptions, do not enable an accurate representation of the typical three-dimensional response, and often they do not provide realistic predictions of the development of damage in the various components including arches, piers and spandrel walls. In this paper, two alternative 3D finite-element modelling strategies offering different balance between sophistication and computational efficiency are presented. The first approach is based on a detailed mesoscale masonry model, where a distinction is made between constituents allowing for an accurate description of masonry under various bond conditions. The second approach is based on a macroscale representation, where a homogeneous description of masonry is assumed. In both approaches, the interactions between the spandrel walls and the backfill and arches, as well as between the backfill and the arches' extrados, are explicitly incorporated into the model. This interaction effect is investigated with the two approaches, and comparisons are made between the respective simulations to illustrate the relative benefits of mesoscale and macroscale modelling.