This paper presents a modeling approach for high-fidelity blind-prediction of dynamic responses of 3D-printed masonry-like structures, as part of a contest organized by Pacific Earthquake Research Center (PEER) for simulating shake table tests on 29 identical ⨅-shaped 1:15-scaled sand-based 3D-printed specimens, each subjected to a different earthquake. The contest challenged participants to predict experimental outcomes without access to test results. Leveraging their modeling approach originally developed for regular masonry, the authors proposed an innovative methodology to simulate these structures, implementing extensions to overcome challenges such as representing their continuum nature within a discrete block-and-joint framework and simulating their small-scale response via 1:1-scale counterparts. The numerical model blind-predicted the experimental outcomes with highest accuracy among participants. Parametric studies, before and after access to modal characteristics, showed the importance of such information for simulation accuracy, and the ability of the approach to investigate variability of dynamic responses in complement to physical tests.

The seismic vulnerability of historical masonry structures has been extensively studied, with efforts primarily focused on assessing their earthquake resistance. However, such studies often consider these structures in isolation, disregarding their urban context. In densely built environments, the collapse of adjacent buildings during an earthquake can have a devastating impact on nearby heritage structures, even if they are inherently capable of withstanding seismic loads. On February 6, 2023, two major earthquakes, with magnitudes of Mw 7.7 and Mw 7.6, occurred nine hours apart, affecting the southeastern region of Türkiye. Post-earthquake site investigations revealed that the collapse of the historical Adıyaman Grand Mosque was likely triggered by the failure of a substandard reinforced concrete building in close proximity. This paper aims to investigate the failure mechanism of the Adıyaman Grand Mosque in a broader context. Preliminary study highlights the importance of conducting an extended analysis for heritage structures in urban environments, for reasons such as: (i) the complex interactions between buildings in densely populated areas during earthquakes, (ii) the detrimental effect of the failure of a nearby building on heritage structures, and (iii) the development of more effective mitigation strategies to protect and preserve heritage structures in such environments.

Unreinforced masonry structures are a significant percentage of the global building stock and are often vulnerable to seismic events due to their inherent structural weaknesses and limited deformation capacity. Although seismic codes promote regularity in structural design, achieving this in unreinforced masonry buildings is often a challenging task. Despite extensive research using shake table tests, quasi-static testing of unreinforced masonry buildings remains limited, particularly in the presence of plan irregularity and rigid diaphragm. The present study addresses this research gap by investigating the seismic response of a half-scale, two-story, unreinforced masonry building with plan irregularity through cyclic quasi-static testing. The experimental campaign presented here shows the findings from two tests, including dynamic identification. The first test indicated torsional amplification and rocking-induced wall detachment during the pre-peak response. These results prompted modifications to the experimental setup, including the addition of extra weight to prevent overall rocking and the repairing of the boundary interface to re-establish structural integrity for subsequent testing. The initial results highlight the influence of plan irregularity within the pre-peak behaviour and provide a basis for further exploration in the seismic assessment of irregular, unreinforced masonry buildings.

Masonry buildings of historical centres are usually organized within aggregates, whose structural performance against seismic actions is challenging to predict and constitutes still an open issue. The SERA—AIMS (Seismic Testing of Adjacent Interacting Masonry Structures) project was developed to provide additional experimental data by testing a half-scale, two-unit stone masonry aggregate subjected to two horizontal components of dynamic excitation. In this context, this paper investigates the reliability of the modelling approach and the assumptions adopted to generate a three-dimensional continuum finite element model. The work involves two stages, namely a blind pre-diction and a post-diction phase, and proposes a series of simulation analyses including a strategy to shorten the actual records and save computation costs. The study was performed to investigate the extent of uncertainty in modelling for such masonry aggregates in relation to the experimental outcomes. Pre-diction results were proven to be not accurate in terms of predicted displacements and damage patterns. The upgrades introduced for the post-diction analyses, including the calibration of the elastic modulus and the introduction of a non-linear interface between the two units, allowed to improve the outcomes, with reasonable results in terms of predicted base shear force, displacements along Y-direction and damage pattern for the non-linear stage. The overall approach showed to be appropriate for the structural analysis of existing masonry aggregates, but the accurate modelling of this type of structure remains challenging due to the high level of uncertainties.

Drift-based performance assessment has been a practical tool among the research and engineering community. However, several studies showed that there are several critical issues such as seismic damage definitions and their quantifications related to the displacement-based approach when it is applied not only to modern masonry structures but also to historical ones. The main reason is due to (i) failure mode dependency, (ii) geometry, loading and boundary conditions, (iii) inadequate prediction of the failure modes based on in-plane capacity formulations given in the codes. The present article discusses the reliability of drift limit values proposed by different codes and guidelines by comparing drift values derived in two datasets of masonry piers through considering an application to a real case study. It is observed that performance-based assessment is mainly based on the failure mode of the masonry structure, while the Guideline for Earthquake Risk Management of Historical Structures in Turkey, which is widely used in practice, proposes drift limits that are independent of the masonry behavior. Without consideration of the behavior mode can lead to incorrect assumptions and hence unconservative performance assessment outcomes for the architectural heritage.