Dynamic Identification of the Collapse Mechanisms of a Masonry Arch

The preservation, the safeguard and the valorization of the existing architectural heritage requires the development of theoretical and experimental approaches that can effectively identify any damage of the structures that could lead to their collapse. In the case of masonry constructions, the methodology becomes complex both due to the uncertainties deriving from the mechanical behavior of the masonry material, and due to the necessity to use contactless experimental approaches, which do not lead to the damage of the structure and can also be performed during the service life phase. In this article, we propose a damage identification method for masonry arches and vaults, based on the analysis of the dynamic tests results. In particular, our approach is able to identify the collapse mechanism of masonry curved structures in terms of position of hinges and depths of cracks. The case study consists of a clay-brick masonry arch subjected to an eccentric load on extrados. The experimental values of frequencies were used to calibrate a numerical model of the undamaged arch. A comparison between numerical and experimental frequencies values related to damaged and undamaged configuration was allowed to develop an effective approach to identify the collapse mechanism of arch.