  The structural response of masonry arches is strongly dominated by the arch
geometry, the stone block dimensions and the interaction with backfill material
or surrounding walls. Due to their intrinsic discontinuous nature, the
nonlinear structural response of these key historical structures can be
efficiently modelled in the context of discrete element approaches. Smeared
crack finite elements models, based on the assumption of homogenised media and
spread plasticity, fail to rigorously predict the actual collapse behaviour of
such structures, that are generally governed by rocking and sliding mechanisms
along mortar joints between stone blocks. In this paper a new Discrete
Macro-Element Method (DMEM) for predicting the nonlinear structural behaviour
of masonry arches is proposed. The method is based on a macro-element
discretization in which each plane element interacts with the adjacent elements
through zero-thickness interfaces and whose internal deformability is related
to a single degree of freedom only. Both experimental and numerical validations
show the capability of the proposed approach to be applied for the prediction
of the non-linear response of masonry arch structures under different loading
conditions.
