Abstract The out-of-plane (OOP) dynamic behavior of unreinforced masonry (URM) gable walls was investigated in this paper using a high-fidelity block-based numerical modeling approach, building on the participation of the authors in the ERIES SUPREME blind prediction competition. In this paper, the numerical models developed for the competition were updated based on the experimental data published after the competition to further improve accuracy. The improvement was obtained by slight recalibration of mortar joint tensile strength and friction between the walls and the loading set-up. The updated models were also adopted to simulate a third wall originally excluded from the competition. The models were then used to complement the experimental campaign with additional configurations in a parametric study. Specifically, the influence of roof-wall connections and pre-existing damage on the performance of the gable walls were examined to address gaps identified in both experimental and numerical studies of the past. Stronger roof-wall connections, while improving global stability and increasing wall OOP strength in the static regime by up to 140%, led to collapse at dynamic loading intensities reduced by an average of 28% and up to a maximum of 57%. This early collapse resulted from the transfer of larger dynamic demands to the gable walls. This higher demand transfer also caused earlier damage initiation and considerable changes in collapse mechanisms, effects not captured by static analysis, highlighting the uncertainties governing dynamic behavior and the need for robust methodologies to address them. Finally, light pre-damage, modelled in this study as a crack at the base of the walls, had only a minor influence on failure mechanisms and OOP resistance.
Ghezelbash et al. (Wed,) studied this question.