PSI - Issue 78

Ciro Canditone et al. / Procedia Structural Integrity 78 (2026) 379–386

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Further analyses were run for the most severe scenarios (that is, those involving 33% and 100% of L x and L y ) to assess the role played by the inclusion of pre-existing damage within the models. In both cases, the collapse sequence was not significantly affected by presence of pre-existing cracks. Nevertheless, some minor differences can be observed with regards to the volumes involved in the final collapse mechanism, with more severe damage being observable in pre-damaged model. Small differences were also observed with regards to the failure planes within the Loggia’s side walls, which were conditioned by the presence of preferential slip planes within the pre-damaged model, as expected. It should be noted, though, that the undamaged models are observed to develop, when subjected to gravity loads, an initial crack pattern similar to that observed on site and implemented in the pre-damaged model. This confirms the observed crack pattern to be closely associated with vertical loading conditions and the accuracy of the numerical model in capturing salient features of Loggia’s structural behaviour and load paths. 5. Conclusions The structural performance and vulnerability of URM buildings, particularly heritage buildings, to geotechnical hazards is significantly less explored than those to other hazards such as earthquakes. By contrast, previous works on URM buildings’ response to geotechnical hazards mainly focused on static or quasi-static loading cases, such as slow moving landslides and subsidence or excavation-induced soil settlements. This has left unaddressed a significant research gap on the performance to be expected under sudden foundation-level failures associated with, for instance, bedrock failure. In this paper, advanced numerical analyses based on a highly detailed, discontinuous numerical model of a real URM heritage building ― the Consoli Palace Loggia located in Gubbio, Italy ―have been presented . A simplified micro-modelling approach was adopted to incorporate the effects of masonry bond pattern and pre-existing damage conditions in the analysis. Multiple bedrock failure scenarios were implicitly simulated by removing base restraints, capturing load redistribution and inertial effects via nonlinear dynamic analyses. Complex progressive collapse sequences were simulated, highlighting a lack of structural robustness to sudden foundation-level failures. A significant vulnerability source is found in the presence of vaulted systems, which may increase displacement demand onto adjacent loadbearing walls due to gradual loss of lateral support and resulting changes in their geometrical configuration, hence triggering cascading effects that include the projection of structural debris onto adjacent structures. A comparison is also drawn with regards to the initial stress and displacement states, progressive collapse sequences and final damaged configurations of undamaged models. Analysis results highlight that pre-existing cracks mainly affect the position of potential failure planes, rather than initial stress and displacement states, collapse mechanisms and sequences. Therefore, this study highlights the potential for AEM-based detailed numerical modelling to be used in structural analysis of both undamaged and pre-damaged URM structures subjected to abnormal loading conditions, particularly in near-collapse and collapse stages. Further developments might deal with the analysis of retrofitted structural configurations, for instance by considering the presence of tie rods and other strengthening systems, such as textile reinforced mortars, and the development of full-scale models of Consoli Palace, to assess safety conditions and structural robustness to abnormal loading conditions. Acknowledgements The study was developed within FAIL-SAFE project ("near-real-time perFormance Assessment of exIsting buiLdings Subjected to initAl Failure through multi-scalE simulation and structural health monitoring", Grant No. P2022X7N2S_002, CUP N. E53D23003350006), which was funded by European Union through Next-GenerationEU programme – National Recovery and Resilience Plan (PNRR) – Mission 4, Component 2, Investment 1.1, PRIN 2022 programme of the Italian Ministry of University and Research (D.D. 02/02/2022, n.104). The first author would also like to acknowledge the technical support by Applied Science International, LLC, on the use of the AEM-based “Extreme Loading for Structures” software employed within this study. References Atmaca, E.E; Genç, A.F.; Altunisik, A.C.; Günaydin, M; Sevim, B. 2023. Numerical Simulation of Severe Damage to a Historical Masonry Building by Soil Settlement. Buildings, 13(8). https://doi.org/10.3390/buildings13081973. Calò, M., Malomo, D., Gabbianelli, G. & Pinho, R., 2021. Shake-table response simulation of a URM building specimen using discrete micro-models with varying degrees of detail. Bulletin of Earthquake Engineering, 19:5953-5976.