Author(s): Fathi, Ahmad ; Karimzadeh, Shaghayegh ; Lourenço, Paulo B.
Date: 2025
Persistent ID: https://hdl.handle.net/1822/98340
Origin: RepositóriUM - Universidade do Minho
Subject(s): Arge-Tabriz; Ancient masonry; Cultural heritage buildings; Fragility curves; Stochastic finite-fault simulations; Simulated records; Rupture uncertainties
A comprehensive investigation of the seismic behaviour of the Arge-Tabriz monument, located in a region with very high seismicity in northwest Iran, is presented in this study, making use of simulated ground motions. In seismically active regions characterised by scarcity of large-magnitude events owing to a seismic gap, ground motion simulations provide an effective tool to assess potential scenario earthquakes. In this study, simulations based on the stochastic finite-fault simulation method, incorporating the dynamic corner frequency concept, are employed for scenarios with varying magnitudes. These simulations account for the rupture uncertainties of the North Tabriz Fault in northwest Iran, a region known for its large seismic hazard. The earthquake records are systematically chosen from an extensive dataset covering a broad range of peak ground accelerations. The structure is modelled using the finite element method in ABAQUS. After calibration of the numerical model in terms of the building’s natural frequencies, based on experimental measurements, a non-linear static analysis is performed. Subsequently, the capacity curve of the building is drawn from the pushover analysis using the N2 method, followed by dynamic time history analyses using the simulated ground motion records. Finally, fragility curves are derived based on the drift and Park-Ang damage indices. Thresholds of the Park-Ang damage index for different performance limit states are adopted for masonry. Crack patterns of the structure resulting from numerical modelling are in good agreement with the current situation of the building. The fragility curves, together with the crack patterns, confirm that the monument is able to withstand significant seismic events. The results show that the monument exhibits an extremely high probability of exceeding the damage limitation state, close to 100 %, at a PGA of 0.35 g. For the significant damage limit state, this probability is about 20 % at 0.35 g and increases to 40 % at 0.6 g. Notably, the near collapse limit state was not induced even under the maximum considered PGA of 0.6 g, suggesting a robust ultimate capacity. The findings of this study illustrate the power of using simulated ground motions for exceptional buildings and will guide future conservation efforts for this monument.
