Inelastic behavior of sand-lime mortar joint masonry arches

The response of masonry arch bridges to moving wheel loads was simulated in the laboratory by hanging steel weights from the center of gravity of selected voussoirs of four arches. Elastic and plastic deformations occur in the sand-lime mortar joints, where significant plastic behavior occurs under the first few cycles of loading, then an elastic response follows when the magnitude of load and the load cycles increase. The results from the ultimate load testing show that the collapse load depends significantly on the load history of the arch and that a sliding failure can override a four-hinge mechanism. A model of the arch ring using ADINA and the Drucker-Prager material model indicates that plastic accumulations do not occur after the first load cycle; however, it is believed that sliding occurs between the voussoirs and the mortar, producing small inelastic deformations under moving loads.