Exploring the impact of high-frequency/low-energy earthquakes on old stone masonry structures

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This project will initiate a new strategic international collaboration between McGill University (Montreal, Canada) and the University of Minho (Guimaraes, Portugal) that aims to investigate the unexplored impact of high-frequency/low-energy earthquakes on the out-of-plane (OOP) response of old stone masonry structures, predominant in many populous urban centers of Canada, Portugal and abroad. The high-frequency components of seismic waves are usually disregarded as a source of structural damage for modern constructions, being too high to resonate with their natural frequencies and having small energy content. However, in old stone masonry buildings, high-frequency vibrations can result in irreversible dislocation of masonry units, delamination and rubble core liquefaction, leading to sudden collapses. Although these failure modes are often detected in post-earthquake surveys, this phenomenon remains poorly understood, undermining public safety. The innovative objective of this collaborative project is to quantify the damage extent, strength and displacement capacities of old stone masonry structures under high-frequency/low-energy OOP seismic waves. To open this new line of inquiry at both McGill and UMinho, a multiscale approach is adopted that combines reduced-scale experimental shake-table tests and advanced Discrete Element stochastic simulations of rubble stone masonry sub-structures typical of Canadian regions (but also present in Portuguese construction tradition). Expected outcomes, including the identification of recurrent OOP collapse mechanisms and key seismic performance indexes of representative assemblies, will constitute a unique baseline data on which to inform subsequent research - crucial for devising ad-hoc mitigation strategies and investigating the effect of additional variables. This exploratory study in partnership with UMinho - a world-leading institution in masonry research - will provide participating students enriched training experiences while advancing Canada's position in a deeply under-researched yet extremely relevant area, in line with national priorities (Canada Net-Zero 2050) and commitments (Sendai Framework for Disaster Risk Reduction) for preserving the built environment.