Experimental and numerical investigation on the effect of pre-existing damage in the seismic capacity of masonry arches

Masonry arches are vital elements of architectural heritage. The curved geometry and the compressive strength of masonry provide the capacity to withstand well vertical loading in case movement of the supports is prevented. However, masonry arches are vulnerable to lateral loading, such as those arising from seismic activity. The knowledge of the seismic capacity of masonry arches is thus paramount for safety assessment and effective strengthening. The complexity, cost, and labour involved led to limited seismic studies focused on masonry arches. The tilting table test offers a cost-effective option for seismic capacity assessment through a quasi-static rotation until collapse. The present study investigates the seismic capacity of pre-damaged mortared masonry arches through tilting table tests, complemented by Finite Element (FE)-based nonlinear numerical simulations. Three semi-circular unreinforced masonry arches are tested to identify collapse mechanisms and seismic capacity. The calibrated FE model allows a parametric study to assess the effect of local damage on the seismic capacity. The study reveals that local damage may reduce the arches' capacity by up to 60 % but, more importantly, that such a reduction in the capacity is highly dependent on the location of the damage.