Structural analysis of Monforte de Lemos masonry arch bridge considering the influence of the geometry of the arches and fill material on the collapse load estimation

• Limit analysis and non-linear FE analysis of masonry bridges.
• NDT geometric characterization using terrestrial laser scanning.
• The effect of geometry on the load capacity of masonry arches.
• Influence of backfill on the load capacity of masonry arches.

In this paper the structural assessment of an in-service mediaeval masonry arch bridge is presented. The geometry used to perform the structural computations is based on a precise terrestrial laser scanning survey. Considering these real data, the influence of geometry on the collapse load estimation of the four masonry arches comprising the bridge is addressed. With this purpose, several assumptions regarding different geometric representations are developed and examined on the basis of both rigid block limit analysis and nonlinear finite element models. The impact of precise and simplified geometric representations for both approaches is analyzed and discussed. In addition, other relevant features such as geometric nonlinear effects are also investigated. Finally, the influence of explicitly consider the contribution of the fill material in the structural analysis procedure is assessed. Nonlinear finite element models including arch-fill interaction effects and limit analysis models are used to that aim.