Seismic Performance of the Old Industrial Masonry Chimneys Within the Dickson Incinerator Complex (Montreal, QC)

The earthquake response of slender monumental unreinforced masonry (URM) structures in Eastern Canada — characterised by unique low-to-moderate seismicity and high-frequency ground motions — is still largely unexplored. This paper investigates this research gap through the multi-level seismic evaluation of the 45-m-tall (1950s) clay brick URM chimneys of the Dickson Incinerator complex, considered heritage landmarks in Montreal (QC), Canada. Following a brief historical overview, key geometrical and mechanical properties are derived, and site-specific seismic input records are generated. The proposed assessment in an unprecedented way combines simplified static procedures with classical rocking dynamics, complemented by established continuum Finite Element Method (FEM) simulations, and by novel procedures for URM chimneys, such as the analytical rocking-cylinder model and discontinuum Distinct Element Method (DEM) simulations. Overall, static displacement-based procedures proved effective for fast assessment, providing results consistent with rocking analyses (peak tilts of approximately 10% of the critical threshold) and with the continuum and discontinuum capacity curves. Rocking-block peak tilts are consistent with the rocking-cylinder results only when both horizontal input components are considered, highlighting the importance of accounting for three-dimensional dynamic effects. Dynamic FEM simulations indicate damage concentrating near the chimney top due to higher-mode effects, highlighting the limitations of rigid-body idealisations.