Experimental investigation of a masonry arch subjected to an asymmetric concentrated vertical load and validation via static and kinematic limit analysis

This paper presents an experimental study on the structural response of a 1500-mm span masonry arch subjected to self-weigh and an asymmetric concentrated vertical load increased up to failure. The arch is tested under controlled conditions, with steel plates installed at the springing to prevent parasitic sliding and ensure realistic boundary constraints. Displacement transducers (LVDTs) are strategically positioned to monitor vertical and horizontal displacements at selected points. The experiment allows for a direct observation of the evolution of the failure mechanism up to collapse, characterized classically by the formation of four plastic hinges. A simplified numerical validation is conducted using both static and kinematic limit analysis approaches, each based on Heyman’s no-tension assumptions. The static analysis relies on the construction of a funicular polygon, while the kinematic one is developed according to the principle of virtual work pre-assigning the position of the four hinges. The analytical results, while not introducing novel methodologies, served to verify the consistency of the observed failure mechanism and the collapse load predicted experimentally. The study contributes to a better understanding of the experimental behavior of masonry arches under the application of non-symmetric point loading, providing a benchmark dataset to support future strengthening interventions with innovative reinforcement techniques and to validate numerical models for the structural assessment of heritage masonry.