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This paper presents an experimental program in which 16 full-scale clay brick unreinforced masonry walls were constructed and tested under in-plane cyclic shear loading. These walls have been divided into four sets of nominally identical specimens constructed with the same masonry units from the same mortar composition by the same mason and cured for a consistent period of time. The repeatability of these tests allows for the variability of the peak in-plane shear capacities of these wall configurations to be investigated. Furthermore, these tests were supplemented with material characterization tests, examining the tensile, shear, compressive, and elastic properties of the masonry utilized in this study. In addition, assessments of the accuracy of the current Australian standard for masonry design, as well as that of other expressions found in the literature, have been made. The findings of this analysis indicate that the Australian standard maintains significant limitations in its ability to correctly determine the shear capacity and failure mechanism of masonry shear walls. This error is reduced, but not wholly mitigated through the application of the deterministic equations present in the other design guides. [ABSTRACT FROM AUTHOR]

Unreinforced masonry buildings are highly vulnerable to earthquake damage due to their limited ability to withstand lateral loads, compared to other structures. Therefore, a detailed assessment of the seismic response and resultant damage associated with such buildings becomes necessary. The present study employs machine learning models to effectively predict the seismic response and classify the damage level for a benchmark unreinforced masonry building. In this regard, eight regression-based models, namely, Linear Regression (LR), Stepwise Linear Regression (SLR), Ridge Regression (RR), Support Vector Machine (SVM), Gaussian Process Regression (GPR), Decision Tree (DT), Random Forest (RF), and Neural Networks (NN), were used to predict the building's responses. Additionally, eight classification-based models, namely, Naïve Bayes (NB), Discriminant Analysis (DA), K-Nearest Neighbours (KNN), Adaptive Boosting (AB), DT, RF, SVM, and NN, were explored for the purpose of categorizing the damage states of the building. The material properties of the masonry and the earthquake intensity were considered as the input parameters. The results from the regression models indicate that the GPR model efficiently predicts the seismic response with larger coefficients of determination and smaller root mean square error values than other models. Among the classification-based models, the RF, AB, and NN models effectively classify the damage states with accuracy levels of 92.9%, 91.1%, and 92.6%, respectively. In conclusion, the overall performance of the non-parametric models, such as GPR, NN, and RF, was found to be better than that of the parametric models. [ABSTRACT FROM AUTHOR]

Masonry structures, particularly those used in developing countries and in historic buildings, typically consist of unreinforced masonry (URM) walls connected by timber or reinforced concrete elements. This study proposes enhancements to the existing two-dimensional (2D) deformable frame model (DFM) to enhance its ability in simulating masonry walls with a specific focus on accurately predicting the transient dynamic response of three-dimensional (3D) masonry structures while maintaining a minimal number of degrees of freedom (DOF). For the modeling of URM walls, the DFM framework employs elastic beams and diagonal struts with nonlinear constitutive behavior. Structural elements, such as reinforced concrete or timber reinforcements, are represented using conventional beam finite elements. This paper first reviewed the current DFM configuration, which primarily addresses the in-plane (IP) behavior of URM structures. It then introduced modifications tailored for 3D structural analysis. The reliability of the enhanced model was validated through two approaches. First, a modal analysis compared the results from the updated DFM with those from a reference 3D model based on cubic finite elements. Second, a shaking table experiment conducted on a half-scale masonry house was simulated. The findings demonstrate that, despite its limited number of DOF, the updated DFM effectively captures the main natural vibration modes. Furthermore, it shows the model's ability to predict the nonlinear transient dynamic response of 3D masonry structures with accuracy and limited computational time. [ABSTRACT FROM AUTHOR]

The assessment of unreinforced brick masonry structures and infrastructure is a worldwide challenge for the development of resilient urban areas and preservation of historical assets. Among other factors, the estimation of mechanical performance of masonry in existing construction is of importance. However, the characterisation effort does not always satisfy the requirements from structural analyses point of view, i.e. need of elastic, strength and toughness properties, and/or from technical point of view, i.e. use of conventional technical expertise and limited invasiveness. In this respect, the new RILEM Technical Committee CTM aims at promoting the use of tests on masonry cores for the evaluation of compression and shear properties of unreinforced masonry with regular units. Upon a state-of-the-art review, a database of previous experimental test series will be created to identify influencing factors (e.g., core’s geometry, boundary conditions). Selected testing procedures will be compared at various international institutes for a variety of masonry types typically used in existing structures and infrastructure. By comparing results with standardise tests, correction factors will be identified. Eventually, testing guidelines to characterise masonry with core specimens will be defined and shared within the research and engineering community.

Unreinforced masonry buildings are highly vulnerable to earthquake damage due to their limited ability to withstand lateral loads, compared to other structures. Therefore, a detailed assessment of the seismic response and resultant damage associated with such buildings becomes necessary. The present study employs machine learning models to effectively predict the seismic response and classify the damage level for a benchmark unreinforced masonry building. In this regard, eight regression-based models, namely, Linear Regression (LR), Stepwise Linear Regression (SLR), Ridge Regression (RR), Support Vector Machine (SVM), Gaussian Process Regression (GPR), Decision Tree (DT), Random Forest (RF), and Neural Networks (NN), were used to predict the building’s responses. Additionally, eight classification-based models, namely, Naïve Bayes (NB), Discriminant Analysis (DA), K-Nearest Neighbours (KNN), Adaptive Boosting (AB), DT, RF, SVM, and NN, were explored for the purpose of categorizing the damage states of the building. The material properties of the masonry and the earthquake intensity were considered as the input parameters. The results from the regression models indicate that the GPR model efficiently predicts the seismic response with larger coefficients of determination and smaller root mean square error values than other models. Among the classification-based models, the RF, AB, and NN models effectively classify the damage states with accuracy levels of 92.9%, 91.1%, and 92.6%, respectively. In conclusion, the overall performance of the non-parametric models, such as GPR, NN, and RF, was found to be better than that of the parametric models.

Unreinforced masonry (URM) buildings in historic urban areas of European countries are generally clustered in an aggregate configuration and are often characterized by façade walls mutually interconnected with adjacent ones. As a result, the seismic performance of buildings in an aggregate configuration can be affected by the mutual interaction between the adjacent units. This interaction, often called the aggregate effect, could significantly influence the level of the seismic vulnerability of URM buildings in aggregate configuration toward in-plane and out-of-plane mechanisms, the latter being the object of the present paper. Traditional methods for assessing the seismic vulnerability of URM buildings neglect the interactions between adjacent buildings, potentially underestimating the actual vulnerability. This study aims to derive fragility curves specific for UMR buildings in aggregate configuration and proposes an innovative methodology that introduces the aggregate effect into an analytical approach, previously developed by the authors for isolated URM buildings. The aggregate effect is modeled by accounting for the friction forces arising among adjacent facades during the development of out-of-plane overturning mechanisms by considering different scenarios, based on how façade walls interact with neighboring structures (e.g., whether they are connected to transverse and/or lateral coplanar ones). The proposed approach is applied to a real case study of an Italian historical center. The obtained results demonstrate that the aggregate effect significantly influences the fragility curves of URM buildings arranged in aggregate configurations. This highlights the importance of considering this effect and the usefulness of the proposed approach for large-scale assessments of seismic vulnerability in historic urban areas, contributing to sustainable disaster risk prevention. [ABSTRACT FROM AUTHOR]

The evaluation of the structural behaviour of a masonry Venetian church with a pointed barrel vault is presented in this paper through an analysis following the necessary steps of a monument study. With a detailed geometric model and material estimation, the finite-element method is used to investigate the influence of specific structural parts of the structure, like masonry buttresses and wall connections, on the structural behaviour. The operational modal analysis is used to identify the structure dynamically. The comparison of the eigenfrequencies, which are estimated by in situ measurements and finite-element modal analysis, is used to perform a model identification. The response spectrum analysis, the static analysis after the subsistence of some parts following strengthening proposals, and the transient analysis of specific seismic excitations are used for the evaluation of the structural behaviour. The purpose of the work is to highlight the need for an interdisciplinary approach to the study of a monumental complex structure, regardless of its scale. The coexistence of structural elements of different stiffnesses, such as vaults, elongated walls, buttresses, transverse walls with pediment and belfry, as well as the concha, affects the mechanical behaviour and the pathology of the structure, which is difficult to study with simplifying models. From the analysis, it is concluded that subsidence problems, combined with seismic actions, lead to the cracking of the masonry, while the existence of buttresses limits the extension of the damage and contributes to the stabilization of the structure. [ABSTRACT FROM AUTHOR]

Unreinforced masonry (URM) structure consisting of bricks and mortar suffers severe damage under impact loading, owing to its poor ductility and brittle failure modes. However, natural nacre with a similar structure to that of masonry exhibits superior mechanical properties through the well-designed assembly process. Therefore, a nacre-inspired design method, which hierarchically assembled bricks and engineered cementitious composites (ECC) into novel masonry walls at the macro-scale, was proposed in present study. The variations of the bionic measurements were experimentally explored. Test results demonstrated that the ductility and toughness of the novel masonry structure were dramatically improved by replacing mortar with ECC as horizontal joint and setting artificial local separations. The energy absorption of masonry wall and masonry beam were improved 5.66 times and 8.05 times, respectively. A theoretical frame model for hierarchically-assembled masonry was established, which considered the randomness of masonry and simulated the crack propagation. Finally, a numerical verification was conducted based on the frame model. This study lays the groundwork for applying the nacre-inspired design method in masonry structure to improve its shear properties in terms of ductility and toughness.

Seismic damage shows that the out-of-plane collapse of unreinforced masonry walls is very common. Especially in the teaching buildings, the out-of-plane collapse of the longitudinal load-bearing walls leads to the disproportionate collapse of the building, which results in serious loss of life and property. It is assumed that the in-plane stiffness of the unreinforced masonry floor system is infinite, and the effect of the integral bending of building on the story drift is ignored. The load-displacement relationship for out-of-plane of unreinforced wall under vertical dead load and horizontal seismic load was deduced with the bilinear constitutive relationship of masonry under compression, the second-order effect of vertical load on deformation being considered. The influence of axial compression ratio and the height-thickness ratio of the wall on the failure model and the load-displacement characteristics in the elastic state, ultimate state and collapse state were also studied. A theoretical method for the collapse mechanism and the aseismic design of the unreinforced masonry structure based on displacement was provided. This study has significant implications for the seismic performance design, post earthquake structural reinforcement, and seismic grade evaluation of unreinforced masonry structures.

Masonry structures, particularly those used in developing countries and in historic buildings, typically consist of unreinforced masonry (URM) walls connected by timber or reinforced concrete elements. This study proposes enhancements to the existing two-dimensional (2D) deformable frame model (DFM) to enhance its ability in simulating masonry walls with a specific focus on accurately predicting the transient dynamic response of three-dimensional (3D) masonry structures while maintaining a minimal number of degrees of freedom (DOF). For the modeling of URM walls, the DFM framework employs elastic beams and diagonal struts with nonlinear constitutive behavior. Structural elements, such as reinforced concrete or timber reinforcements, are represented using conventional beam finite elements. This paper first reviewed the current DFM configuration, which primarily addresses the in-plane (IP) behavior of URM structures. It then introduced modifications tailored for 3D structural analysis. The reliability of the enhanced model was validated through two approaches. First, a modal analysis compared the results from the updated DFM with those from a reference 3D model based on cubic finite elements. Second, a shaking table experiment conducted on a half-scale masonry house was simulated. The findings demonstrate that, despite its limited number of DOF, the updated DFM effectively captures the main natural vibration modes. Furthermore, it shows the model’s ability to predict the nonlinear transient dynamic response of 3D masonry structures with accuracy and limited computational time.

A new macro model for the finite element modeling of unreinforced masonry (URM) exhibiting in-plane nonlinear cyclic behavior is proposed. The ultimate objective is to predict the seismic response of multi-story URM buildings. The macro model enables the modeling of URM shear walls with a limited number of degrees of freedom (DOF) at low computation times. The macro model consists of a deformable elastic frame supported by diagonal struts with nonlinear behavior aiming to capture all dissipative phenomena occurring during seismic events. The nonlinear constitutive behavior of diagonal struts is inspired by models documented in the literature, ensuring a robust foundation for the proposed approach. This paper first provides a comprehensive review of the principal models currently available for URM analysis. It then articulates the rationale behind the development of this new numerical model, aiming to address the limitations encountered in existing methodologies and to offer a simple and fast tool for predicting the seismic behavior of URM buildings. Afterward, the new model is presented and tested with the simulations of two experimental campaigns performed on different URM walls. The comparison between experimental and numerical results shows that with a limited number of DOF and parameters, it is possible to obtain a prediction of the experimental results with satisfying accuracy. [ABSTRACT FROM AUTHOR]

This paper proposes an effective approach to realise circular construction with concrete, and shows Unreinforced Masonry as a foundational building block for it. The paper outlines the importance of circularity in building structures. It specifically focuses on the impact of circular construction with concrete on improving the sustainability of the built environment in a rapidly urbanising world economy. Subsequently, the relevance of principles of structural design and construction of unreinforced masonry to achieve circularity is articulated. Furthermore, the paper presents and summarises recent developments in the field of Unreinforced Concrete Masonry (URCM) including digital design tools to synthesise structurally efficient shapes, and low-waste digital fabrication techniques using lower-embodied-emission materials to realise the designed shapes. The paper exemplifies these using two physically realised, full-scale URCM footbridge prototypes and a commercially available, mass-customisable building floor element, called the Rippmann Floor System (RFS). The paper also outlines the benefits of mainstream, industrial-scale adoption of the design and construction technologies for URCM, including accelerating the pathway to decarbonise the concrete industry. In summary, the paper argues that URCM provides a solution to significantly mitigate the carbon emissions associated with concrete and reduce the use of virgin resources whilst retaining its benefits such as widespread and cheap availability, endurance, fire safety, low maintenance requirements and recyclability. [ABSTRACT FROM AUTHOR]

Unreinforced masonry (URM) walls are common load-bearing structural elements in most existing buildings, consisting of masonry units (bricks) and mortar joints. They indicate a highly nonlinear and complex behaviour when subjected to combined compression–shear loading influenced by different factors, such as pre-compression load and boundary conditions, among many others, which makes predicting their structural response challenging. To this end, the present study offers a discontinuum-based modelling strategy based on the discrete element method (DEM) to investigate the in-plane cyclic response of URM panels under different vertical pressures with and without a damp-proof course (DPC) membrane. The adopted modelling strategy represents URM walls as a group of discrete rigid block systems interacting along their boundaries through the contact points. A novel contact constitutive model addressing the elasto-softening stress–displacement behaviour of unit–mortar interfaces and the associated stiffness degradation in tension–compression regimes is adopted within the implemented discontinuum-based modelling framework. The proposed modelling strategy is validated by comparing a recent experimental campaign where the essential data regarding geometrical features, material properties and loading histories are obtained. The results show that while the proposed computational modelling strategy can accurately capture the hysteric response of URM walls without a DPC membrane, it may underestimate the load-carrying capacity of URM walls with a DPC membrane. [ABSTRACT FROM AUTHOR]

This study investigates the effectiveness of a range of timber-based solutions for the seismic and energy retrofitting of existing masonry buildings. These solutions are designed not only to prevent structural collapse during earthquakes but also to create integrated interventions that enhance thermo-physical performance and reduce emissions in existing buildings. Various case scenarios were considered and both mechanical and energetic behaviour post-intervention were evaluated. Timber-engineered products serve as foundational components for the retrofit approach, encompassing one-dimensional vertical elements (strong-backs) and various types of panels (cross-laminated timber panels, laminated veneer lumber panels, and oriented strand board panels). The analyzed retrofit techniques share a common principle involving the attachment of these timber-based elements to the building's wall surfaces through mechanical point-to-point connections. The proposed solutions integrate strong-backs and timber panels with membranes and insulation layers, yielding cohesive, and highly effective interventions. Finite element modeling was employed to analyze the mechanical and thermal responses of the retrofitted walls. A comprehensive comparative analysis of various techniques was conducted to determine the most effective solution for each specific scenario. [ABSTRACT FROM AUTHOR]

Carbon fibre-reinforced polymer (CFRP) emerges as a viable solution for reinforcing unreinforced masonry (URM) walls subjected to shear loads. While masonry structures are straightforward to construct, the complexity of the construction materials, especially in terms of their mechanical properties, poses challenges for numerical studies of their structural behaviour. Walls, being fundamental components in masonry construction, play a crucial role in transferring both horizontal and vertical lateral forces. This study investigates the enhancement of masonry wall behaviour through the reinforcement of CFRP. CFRP reinforcement increases ductility and strength, reducing the risk of failure under shear conditions. Additionally, CFRP composites present a practical solution to strengthening masonry structures compared to traditional reinforcement. However, brick, mortar, and CFRP have not been thoroughly investigated. Experimental tests on the bond behaviour of different configurations of CFRP-retrofitted masonry triplets have not been performed before and are therefore presented in this paper. Triplet specimens, comprising three bricks and two mortar joints, both with and without CFRP strengthening, were subjected to bond testing. The study affirms that masonry triplets strengthened with CFRP under shear loads exhibit strength levels at least four to six times greater than those without CFRP. The experimental work was carried out with eight different CFRP configurations on triplet masonry, and each test was repeated four times. Further, the bond stress-slip relationship in the case of masonry triplets with and without CFRP was predicted with new mathematical equations based on the conducted test results. These equations were included in the commercial finite element software ANSYS and used to conduct simulations of CFRP-reinforced masonry triplets. The numerical results indicate good agreement between the finite element model and the test results. The outcome of this research improves the current knowledge on the use of CFRP to reinforce masonry walls with brick and mortar, which will contribute to the understanding of the effect of CFRP on masonry structures. [ABSTRACT FROM AUTHOR]

Unreinforced masonry (URM) is a construction of brick or concrete block unit that is joined together using mortar, without steel reinforcement. Because of the heterogeneous nature and difference in mechanical properties of the masonry elements, analyzing and capturing the structural behaviour of URM walls under various loading conditions is therefore complex. In recent decades, research efforts have been focused on addressing and understanding the compressive behaviour of URM walls from the experimental viewpoint. However, from the existing experimental literature, there is a significant degree of variation in the mechanical and geometric properties of URM walls, especially the comprehensive comparison of apparently equivalent test parameters, which has yet to be examined. It is therefore necessary to highlight and critically examine major results derived from the experimental literature to better understand the performance of URM walls under compressive loads. This review paper presents the assessment performance with regard to axial compressive tests on URM walls, along with comprehensive comparisons among the experimental literature findings on the basis of masonry construction methods and various influencing parameters. Emphasis in the literature has been placed chiefly on the masonry elements, design provisions, axial load, slenderness ratio, openings, and stress–strain response. Based on observations from the study, experimental development trends have been highlighted to identify and outline potential directions for future studies. [ABSTRACT FROM AUTHOR]

An evaluation of the seismic behavior of a massive masonry monument with vaults, namely, the Neoria complex at the old port of Chania, is presented here. The usage of modal response analysis requires the combination of many eigenmodes in order to capture the required amount of vibration energy. Alternatively, a number of earthquakes can be used within a time domain response analysis in order to evaluate the response and, subsequently, the strength of the structure. Results of linear analysis are compared here, since this is what is required from current seismic codes. A nonlinear analysis with adequate material models will also be presented in order to demonstrate a comparison with linear analysis and a prediction of damage appearance under ultimate conditions. From the present investigation, it is shown that the results of the modal analysis and the linear time-step analysis are comparable. Therefore, some confidence is gained towards using the results for the design of strengthening and rehabilitation studies. Nonlinear models are very sensitive with respect to design earthquakes and material models. Therefore, at this stage, their results are used for the identification of areas where interventions must be performed very carefully. [ABSTRACT FROM AUTHOR]

This research performs a parametric study based on Equivalent Single Degree of Freedom (ESDOF) models for simplified seismic analysis of unreinforced masonry (URM) structures. This is a necessary action due to the fact that it is not affordable to model and analyze populations of masonry buildings by using detailed continuum-based models during regional seismic damage and loss estimation studies. Hence, this study focuses on the sensitivity of major structural parameters of a selected idealized hysteretic model for URM buildings. The numerical models are subjected to region-specific simulated ground motion time histories generated using validated seismological parameters. The variations in dynamic analysis results are evaluated using statistical tools for major structural and seismological parameters. The results reveal that the strength factor is the most influential structural parameter, whereas magnitude and distance have a significant impact on the response of idealized URM models as seismological parameters. Furthermore, the specific seismic performance exhibiting limited ductility capacity and the narrow margin of safety between the initial state of inelastic behavior and the ultimate (collapse) state for URM buildings is verified by the statistical approaches employed in this study. [ABSTRACT FROM AUTHOR]

The seismic performance assessment of heritage architecture presents many challenges due to the restrictions set forth by the conservation principles to protect the associated social and cultural values. These buildings are typically characterized by unreinforced masonry walls connected by tie-rods, vaults, and wooden floors. The era of construction dates to the time when seismic design regulations were largely unknown, making heritage structures potentially vulnerable to earthquake damage. This study presents the seismic performance assessment of the Jesuit College located in the southern part of the Old City of Dubrovnik. A series of field surveys were conducted to qualitatively examine the material composition and obtain geometrical details in part of the Croatian Science Foundation research project IP-2020-02-3531 entitled "Seismic Risk Assessment of Cultural Heritage in Croatia—SeisRICHerCRO". The structural response is thoroughly investigated by means of a complex finite element model calibrated using the frequencies determined from ambient vibration measurements and material characteristics obtained from the literature review of representative cultural heritage buildings. The seismic performance is evaluated using linear static and response spectrum analysis in accordance with Eurocode 8 guidelines for the demand seismic action level. The numerical analysis indicates several structural components in the building exhibiting high shear stress concentration and exceeding the elastic tensile limit under the demand ground acceleration level. The assessment further reveals substantial out-of-plane bending of vulnerable wall components (identified by local mode shapes) at low peak ground acceleration levels. The stress concentration in numerous structural components leads to the identification of vulnerable zones where retrofitting measures are essentially required. [ABSTRACT FROM AUTHOR]

This paper focuses on a structural reliability-based assessment of clay brick unreinforced masonry (URM) walls subjected to uniformly distributed out-of-plane loads in one-way vertical bending. Stochastic models combining finite element analysis (FEA) and Monte Carlo simulations (MCS) are used to account for spatial variability of the flexural tensile bond strength when estimating the wall failure loads. The strength of URM walls is known to be influenced by the flexural tensile bond strength, which is subject to high spatial variability as batching, workmanship, and environmental exposure alter the strength of this bond. For this assessment, single skin walls have been considered with bond strength statistics seen in typical construction. The model error statistics available for similar walls are combined with the results of the spatial stochastic FEA and probabilistic load models to determine the reliability index corresponding to the Australian Standard for Masonry Structures AS 3700 design of members in vertical bending. It was found that existing levels of reliability exceed target reliabilities, and the capacity reduction factor can be increased from 0.60 to 0.65 for URM walls in one-way vertical bending while still providing an acceptable level of reliability. A sensitivity analysis showed this finding to be robust. [ABSTRACT FROM AUTHOR]

The evaluation of the structural behaviour of a masonry Venetian church with a pointed barrel vault is presented in this paper through an analysis following the necessary steps of a monument study. With a detailed geometric model and material estimation, the finite-element method is used to investigate the influence of specific structural parts of the structure, like masonry buttresses and wall connections, on the structural behaviour. The operational modal analysis is used to identify the structure dynamically. The comparison of the eigenfrequencies, which are estimated by in situ measurements and finite-element modal analysis, is used to perform a model identification. The response spectrum analysis, the static analysis after the subsistence of some parts following strengthening proposals, and the transient analysis of specific seismic excitations are used for the evaluation of the structural behaviour. The purpose of the work is to highlight the need for an interdisciplinary approach to the study of a monumental complex structure, regardless of its scale. The coexistence of structural elements of different stiffnesses, such as vaults, elongated walls, buttresses, transverse walls with pediment and belfry, as well as the concha, affects the mechanical behaviour and the pathology of the structure, which is difficult to study with simplifying models. From the analysis, it is concluded that subsidence problems, combined with seismic actions, lead to the cracking of the masonry, while the existence of buttresses limits the extension of the damage and contributes to the stabilization of the structure.

Unreinforced masonry (URM) made with soft bricks comprises a large percentage of the building stock in developing countries. However, the poor performance of URM piers during earthquakes has led to renewed interest in understanding their behavior under lateral loads. Little experimental data is available on the seismic response, analysis, and design of URMs made of soft bricks. In this study, the micro-modeling technique is used to simulate the in-plane behavior of load-bearing, soft-brick URM piers. The parameters required in the constitutive models are obtained from material tests and used to develop a calibrated numerical model of the URM piers. Piers with various aspect ratios subjected to various axial stresses are numerically modeled to obtain monotonic and cyclic responses, and their critical displacement limit states are identified. Changes in the failure modes of masonry piers with variations in the aspect ratio and axial stress are established. Load-bearing piers exhibit three distinct failure modes: bed sliding, diagonal shear cracking, and flexure, depending on the aspect ratio and axial stress. The seismic fragility of each pier failure type is examined using nonlinear time history analyses. The results show that bed-sliding piers collapse at extremely low PGA levels. Piers failing through diagonal shear cracking also fail at low PGA levels. Flexural piers can resist seismic forces up to a slightly higher PGA level and thus are the last to collapse. The results also indicate that the effect of uncertainty in ground motions is more significant than the effect of variability in the masonry pier capacities.

Abstract This work intends to provide seismic vulnerability analysis for a building stock in Al Khalifa District, Fatimid Cairo while focusing on the historic buildings in the area. The work represents part of an interdisciplinary study targeting the management and conservation of a UNESCO World Heritage Site. The project inspects several aspects including behavior of masonry walls, structural health monitoring of selected structures, conservation studies, in addition to influence of rising ground water. In the current study, seismicity of Egypt generally and Cairo specifically is reviewed. Afterwards, large-scale seismic vulnerability is adopted to calculate the vulnerability index for buildings within the study area. Data are collected through extensive on-site surveys for more than one hundred buildings. Observed typologies are listed alongside possible mechanisms of failure. Egypt has moderate seismic hazard; however, many buildings are prone to damage due to inadequate seismic design. This leads to retrofitting requirements to reduce seismic vulnerability and adhere to imposed seismic requirements in design codes. The study is intended to understand seismic risk of buildings within study area as part of a comprehensive study. Developed vulnerability map show that many buildings are prone to damage during seismic events. Article Highlights Seismic vulnerability of building samples in a study area within Old Cairo is assessed and presented in the form of a vulnerability map. Structural characteristics of buildings are detailed and investigated. Signs of deterioration are analyzed, and mechanisms of failure are featured.

Unreinforced masonry has been for centuries one of the most widespread constructive techniques for both massive structures and civil buildings (e.g., palaces, hospitals, houses), for the most still standing nowadays. Their future conservation relies on (i) their protection from main natural threats (e.g., earthquakes) and (ii) updating to current functionality and hygrothermal standards. In the former framework, existing masonry buildings proved to have some intrinsic vulnerabilities, depending on composition (units and binder) and structural typologies. Based on experience gathered from seismic events, various retrofitting techniques have been proposed. In such a context, the use of cross-laminated timber (CLT) components is a very promising solution, in terms of compatibility with built heritage and integration of seismic and hygrothermal performances. This paper aims at improving the knowledge of the structural performances of compound timber–masonry interventions by numerical simulations carried out at (i) pier scale and (ii) building full scale via finite element modeling and nonlinear static analyses (pushover). First, a coupled timber–masonry wall was simulated and underwent sensitivity analyses with the properties of both components varying; then, the optimized solution was applied to a case study to assess the intervention benefits, and the results were also cross-checked with those of more traditional interventions (e.g., grout injections).

Unreinforced masonry structures are vulnerable to seismic actions and frequently exhibit partial or global out-of-plane wall collapse when subjected to large intensity earthquake shaking. The installation of timber strong-backs connected to the masonry surface with mechanical fasteners is a reversible and effective strengthening solution that considerably improves the out-of-plane response of masonry walls. An analytical formulation is presented that enables the out-of-plane behaviour of unreinforced masonry walls seismically retrofitted with timber strong-backs to be described, with limit analysis theorems being utilised to establish the lateral capacity curve and the demands on the masonry wall, on the timber strong-backs, and on the fastener components of the retrofitted walls, thereby enabling the design of retrofit interventions. These analytical predictions were validated using experimentally derived data from five full-scale masonry wall tests and were also compared with simulations obtained from a numerical model developed using the software SAP2000 and adopting a simplified micro-modelling approach. Analytically derived load actions were consistent with experimental values (errors < 5 %) and were compatible with the numerical deformation results (errors < 10 %). The expected performance of various retrofitted wall configurations is then reported as support for general considerations regarding the retrofit solution. • A new method for predicting the OOP behaviour of URM walls strengthened timber strong-backs is proposed. • The design method is validated on FE simulations and experimental testing. • The analytical approach allows the optimization of the timber retrofit. • The calculations predict the response of the tested retrofitted walls adequately. [ABSTRACT FROM AUTHOR]

A new macro model for the finite element modeling of unreinforced masonry (URM) exhibiting in-plane nonlinear cyclic behavior is proposed. The ultimate objective is to predict the seismic response of multi-story URM buildings. The macro model enables the modeling of URM shear walls with a limited number of degrees of freedom (DOF) at low computation times. The macro model consists of a deformable elastic frame supported by diagonal struts with nonlinear behavior aiming to capture all dissipative phenomena occurring during seismic events. The nonlinear constitutive behavior of diagonal struts is inspired by models documented in the literature, ensuring a robust foundation for the proposed approach. This paper first provides a comprehensive review of the principal models currently available for URM analysis. It then articulates the rationale behind the development of this new numerical model, aiming to address the limitations encountered in existing methodologies and to offer a simple and fast tool for predicting the seismic behavior of URM buildings. Afterward, the new model is presented and tested with the simulations of two experimental campaigns performed on different URM walls. The comparison between experimental and numerical results shows that with a limited number of DOF and parameters, it is possible to obtain a prediction of the experimental results with satisfying accuracy.

Unreinforced masonry (URM) walls are common load-bearing structural elements in most existing buildings, consisting of masonry units (bricks) and mortar joints. They indicate a highly nonlinear and complex behaviour when subjected to combined compression–shear loading influenced by different factors, such as pre-compression load and boundary conditions, among many others, which makes predicting their structural response challenging. To this end, the present study offers a discontinuum-based modelling strategy based on the discrete element method (DEM) to investigate the in-plane cyclic response of URM panels under different vertical pressures with and without a damp-proof course (DPC) membrane. The adopted modelling strategy represents URM walls as a group of discrete rigid block systems interacting along their boundaries through the contact points. A novel contact constitutive model addressing the elasto-softening stress–displacement behaviour of unit–mortar interfaces and the associated stiffness degradation in tension–compression regimes is adopted within the implemented discontinuum-based modelling framework. The proposed modelling strategy is validated by comparing a recent experimental campaign where the essential data regarding geometrical features, material properties and loading histories are obtained. The results show that while the proposed computational modelling strategy can accurately capture the hysteric response of URM walls without a DPC membrane, it may underestimate the load-carrying capacity of URM walls with a DPC membrane.

Carbon fibre-reinforced polymer (CFRP) emerges as a viable solution for reinforcing unreinforced masonry (URM) walls subjected to shear loads. While masonry structures are straightforward to construct, the complexity of the construction materials, especially in terms of their mechanical properties, poses challenges for numerical studies of their structural behaviour. Walls, being fundamental components in masonry construction, play a crucial role in transferring both horizontal and vertical lateral forces. This study investigates the enhancement of masonry wall behaviour through the reinforcement of CFRP. CFRP reinforcement increases ductility and strength, reducing the risk of failure under shear conditions. Additionally, CFRP composites present a practical solution to strengthening masonry structures compared to traditional reinforcement. However, brick, mortar, and CFRP have not been thoroughly investigated. Experimental tests on the bond behaviour of different configurations of CFRP-retrofitted masonry triplets have not been performed before and are therefore presented in this paper. Triplet specimens, comprising three bricks and two mortar joints, both with and without CFRP strengthening, were subjected to bond testing. The study affirms that masonry triplets strengthened with CFRP under shear loads exhibit strength levels at least four to six times greater than those without CFRP. The experimental work was carried out with eight different CFRP configurations on triplet masonry, and each test was repeated four times. Further, the bond stress-slip relationship in the case of masonry triplets with and without CFRP was predicted with new mathematical equations based on the conducted test results. These equations were included in the commercial finite element software ANSYS and used to conduct simulations of CFRP-reinforced masonry triplets. The numerical results indicate good agreement between the finite element model and the test results. The outcome of this research improves the current knowledge on the use of CFRP to reinforce masonry walls with brick and mortar, which will contribute to the understanding of the effect of CFRP on masonry structures.

Unreinforced masonry (URM) is considered one of the most cost-effective structural typologies for low-rise buildings in seismic regions. Near-field (NF) ground motions are sometimes characterized by high-velocity pulses that are typically more destructive than far-field (FF) seismic events. Therefore, a seismic fragility analysis of low-rise URM building typologies subjected to NF and FF seismic events was performed. Four URM walls were chosen, and nonlinear models of the walls were developed based on the double-modified, multiple vertical line element model (DM-MVLEM). The zero-moment coefficient was used to determine the effective uncracked section length of a pier. This parameter must be calculated for each pier of a perforated URM wall to derive the maximum shear strength of the piers used in a nonlinear model development process. A simplified analytical method was proposed to obtain the zero-moment coefficient factor of piers by performing linear static analysis on nine perforated walls and regression analyses of the results. Subsequently, nonlinear pushover analysis was performed to derive the capacity curves, and the damage limit states were defined for each model according to the Eurocode 8 standard. Subsequently, incremental dynamic analysis (IDA) was performed for each case study by applying FF and NF ground motions. Finally, fragility curves were developed based on the IDA results for each damage limit state. The susceptibilities of one- and two-story URM walls subjected to FF and NF seismic events were investigated by examining the derived fragility curves.

Historical quay walls constructed in unreinforced masonry are integral elements of many cities. Originally designed as gravity retaining walls, they are nowadays often subjected to the action of traffic loads as a result of vehicles travelling on roads constructed on their backfill. This paper presents a numerical analysis procedure for carrying out the structural assessment of quay walls under traffic loads. The procedure simulates the non-linear dynamic response of the quay wall under the effect of the passage of a vehicle. Non-linear dynamic calculations are performed not only to be representative of the actual nature of loading but also to produce realistic estimations of structural safety, load redistribution capacities and displacements. Adopting a tier-based approach, the computational burden typically associated with such simulations is significantly reduced. This is obtained by adopting simplifications which allow for the modelling the 3D soil block comprising the backfill of the quay wall only in the first tier of the procedure. To demonstrate the implementation of the procedure, a detailed application to an existing quay wall in Amsterdam, the Netherlands, is presented. Different foundation damage scenarios are also considered. Though the procedure is presented in this paper for a specific typology of quay walls, it has conceptual and methodological value. With appropriate modifications it can be used for the structural assessment of other earth retaining structures as well, under the effect of vehicular traffic on their backfills.

The research focuses on shared built heritage, which forms one of the most vulnerable parts of the building stock in historic centres. To prevent severe damage to this building category and to aid decision-making, the paper presents a rapid seismic vulnerability assessment procedure based on an engineering approach to safety assessment. The construction of fragility curves is developed on a probabilistic framework on the computed set of Safety Factors over a range of considered Peak-Ground-Accelerations. Input data necessary for the computations are extracted from CARTIS database. The methodology is implemented in a spreadsheet combined with a script in Visual Basic for Applications. Two case studies are used to demonstrate the applicability to a single building and at the territorial scale. Results show that the proposed methodology allows for a rapid testing of loss of structural performance given various scenarios, as well as contributing by prioritizing interventions in probabilistic terms.

Masonry is the oldest building material, yet it is also the least understood due to the non-linear and composite nature of masonry, which consists of brick units, mortar, and unit-mortar contact. In this paper, the response of a two-dimensional masonry wall with a window opening subjected to an in-plane lateral pushover loading is simulated by varying the interface properties of brick such as crushing, elastic, cracking, and shear properties. The simplified micro-modeling technique with the Engineering Masonry model for bricks and linear stiffness properties for the interfaces in the bed and head joints is employed to investigate the geometric nonlinear behavior of the masonry wall. The pushover curves obtained from the numerical simulations indicate that there is a significant influence on the lateral load response of the wall due to elastic, crushing, and shear parameters while the cracking parameters have less impact on the ductile capacity of the structure. Moreover, the study is also extended to examine the effect of bond patterns such as English, stretcher, Flemish, and header bonds with varied aspect ratios of 1, 1.5, and 0.75. In all four bond patterns, it was observed that the walls with lower aspect ratios exhibited higher strength. Further, in comparison to the other bond patterns, walls with the Flemish bond pattern demonstrated higher strengths at both lower and higher aspect ratios. [ABSTRACT FROM AUTHOR]

Masonry buildings are generally vulnerable to seismic action, as evidenced extensively in past earthquakes. In order to improve their seismic performance, several modifications have been introduced, such as reinforcing or confining the masonry. This paper presents a seismic analysis and fragility assessment procedure for non-engineered masonry building typologies, employing the applied element method (AEM). Compared to buildings with stiff diaphragms, the conventional pushover-based procedure is challenging for the seismic assessment of masonry buildings with flexible diaphragms, due to the lack of a global box-like behaviour. This study first presents a novel and validated method for nonlinear pushover analysis, independent of the type of diaphragm action on the building, by applying incremental ground acceleration and by considering suitable engineering demand parameters for the assessment of lateral capacity. Based on the failure mechanisms, a seismic performance assessment and fragility evaluation approach is then proposed, for reliable accounting of both the in-plane and out-of-plane failure modes. Finally, the proposed methodology is applied to a number of unreinforced and confined masonry school buildings with different seismic detailing levels, as often found in the Himalayan belt and beyond. [ABSTRACT FROM AUTHOR]

The authors developed two types of block systems consisting only of main block and key block without joint mortar in consideration of seismic performance and workability. Two types of block systems have different key block shapes: One is the peanuts shape and the other is the dumbbell shape. In this study, the proposed two types of block walls as well as a typical block wall were experimentally investigated to evaluate the seismic performance. In the tests, full-scale, single-story specimens were tested under static cyclic in-plane loading, and failure patterns and cracks were carefully observed. In this paper, the loading bearing capacity, energy dissipation capacity and reuse ratio of block walls are discussed in detail. As a result, the deformability, energy absorption capacity and reuse ratio of the proposed block systems were considerably higher than those of typical block system.

Retrofitting the existing building stock is needed since it can cause significant losses as in case of a damaging earthquake, particularly in structures used for public services, such as schools. Effective and optimal seismic retrofitting measures applied to existing masonry constructions should arise from a strong understanding of the vulnerabilities associated with each structural typology and construction practice. Using representative structural configurations of the masonry buildings used in the education sector from Romania, the paper aims to evaluate the seismic risk associated to the existing buildings and to support informed decision-making for seismic retrofitting measures. Starting from a broad database of school masonry buildings, potential losses were evaluated considering two seismic hazard scenarios. For an earthquake having a 63% exceedance probability in 50 years, losses estimated for the education sector comprising masonry structures reached almost 240 mil. € and 2,500 potential casualties. For highlighting that investments in retrofitting masonry structures from the education sector lead to significant reductions of potential losses, prioritization criteria were proposed and cost–benefit analysis was carried out for about 15,000 buildings. Results are presented through graphs and maps that illustrate the distribution of annual failure probabilities at the national level. Therefore, the methodology proposed and the results presented in this paper can represent a valuable tool for substantiating public policies aiming at reducing the seismic risk, in particular for existing masonry structures.

Unreinforced masonry (URM) is a construction of brick or concrete block unit that is joined together using mortar, without steel reinforcement. Because of the heterogeneous nature and difference in mechanical properties of the masonry elements, analyzing and capturing the structural behaviour of URM walls under various loading conditions is therefore complex. In recent decades, research efforts have been focused on addressing and understanding the compressive behaviour of URM walls from the experimental viewpoint. However, from the existing experimental literature, there is a significant degree of variation in the mechanical and geometric properties of URM walls, especially the comprehensive comparison of apparently equivalent test parameters, which has yet to be examined. It is therefore necessary to highlight and critically examine major results derived from the experimental literature to better understand the performance of URM walls under compressive loads. This review paper presents the assessment performance with regard to axial compressive tests on URM walls, along with comprehensive comparisons among the experimental literature findings on the basis of masonry construction methods and various influencing parameters. Emphasis in the literature has been placed chiefly on the masonry elements, design provisions, axial load, slenderness ratio, openings, and stress–strain response. Based on observations from the study, experimental development trends have been highlighted to identify and outline potential directions for future studies.

Many conventional rapid visual screening (RVS) methods for the seismic assessment of existing structures have been designed over the past three decades, tailored to site-specific building features. The objective of implementing RVS is to identify the buildings most susceptible to earthquake-induced damage. RVS methods are utilized to classify buildings according to their risk level to prioritize the buildings at high seismic risk. The conventional RVS methods are employed to determine the damage after an earthquake or to make safety assessments in order to predict the damage that may occur in a building before an impending earthquake. Due to the subjectivity of the screener based on visual examination, previous research has shown that these conventional methods can lead to vagueness and uncertainty. Additionally, because RVS methods were found to be conservative and to be partially accurate, as well as the fact that some expert opinion based developed RVS techniques do not have the capability of further enhancement, it was recommended that RVS methods be developed. Therefore, this paper discusses a fuzzy logic based RVS method development to produce an accurate building features responsive examination method for unreinforced masonry (URM) structures, as well as a way of revising existing RVS methods. In this context, RVS parameters are used in a fuzzy-inference system hierarchical computational pattern to develop the RVS method. The fuzzy inference system based RVS method was developed considering post-earthquake building screening data of 40 URM structures located in Albania following the earthquake in 2019 as a case study. In addition, FEMA P-154, a conventional RVS method, was employed to screen considered buildings to comparatively demonstrate the efficiency of the developed RVS method in this study. The findings of the study revealed that the proposed method with an accuracy of 67.5% strongly outperformed the conventional RVS method by 42.5%. [ABSTRACT FROM AUTHOR]

Seismic vulnerability assessment of historical unreinforced masonry (URM) buildings is crucial for the authorities due to the high susceptibility of historical URM buildings to earthquakes. Open system for earthquake engineering simulation (OpenSees) is a well-known, powerful, and versatile seismic analysis platform. In a lack of a free graphical user interface (GUI) for seismic analysis of URM buildings, Hyperomet was designed to bridge the gap between nonlinear analysis of URM buildings and OpenSees platform. The Hyperomet GUI includes an accurate enough macroelement representing the nonlinear behavior of URM components. The structures can be modeled based on the double-modified multiple vertical line element model (DM-MVLEM) and the Unified method (UM) using the GUI. Calculators for deriving the mechanical properties are provided to minimize the modeling time. Furthermore, the ability to perform various analysis types including incremental dynamic analysis (IDA) is facilitated.

An evaluation of the seismic behavior of a massive masonry monument with vaults, namely, the Neoria complex at the old port of Chania, is presented here. The usage of modal response analysis requires the combination of many eigenmodes in order to capture the required amount of vibration energy. Alternatively, a number of earthquakes can be used within a time domain response analysis in order to evaluate the response and, subsequently, the strength of the structure. Results of linear analysis are compared here, since this is what is required from current seismic codes. A nonlinear analysis with adequate material models will also be presented in order to demonstrate a comparison with linear analysis and a prediction of damage appearance under ultimate conditions. From the present investigation, it is shown that the results of the modal analysis and the linear time-step analysis are comparable. Therefore, some confidence is gained towards using the results for the design of strengthening and rehabilitation studies. Nonlinear models are very sensitive with respect to design earthquakes and material models. Therefore, at this stage, their results are used for the identification of areas where interventions must be performed very carefully.

This research performs a parametric study based on Equivalent Single Degree of Freedom (ESDOF) models for simplified seismic analysis of unreinforced masonry (URM) structures. This is a necessary action due to the fact that it is not affordable to model and analyze populations of masonry buildings by using detailed continuum-based models during regional seismic damage and loss estimation studies. Hence, this study focuses on the sensitivity of major structural parameters of a selected idealized hysteretic model for URM buildings. The numerical models are subjected to region-specific simulated ground motion time histories generated using validated seismological parameters. The variations in dynamic analysis results are evaluated using statistical tools for major structural and seismological parameters. The results reveal that the strength factor is the most influential structural parameter, whereas magnitude and distance have a significant impact on the response of idealized URM models as seismological parameters. Furthermore, the specific seismic performance exhibiting limited ductility capacity and the narrow margin of safety between the initial state of inelastic behavior and the ultimate (collapse) state for URM buildings is verified by the statistical approaches employed in this study.

The seismic performance assessment of heritage architecture presents many challenges due to the restrictions set forth by the conservation principles to protect the associated social and cultural values. These buildings are typically characterized by unreinforced masonry walls connected by tie-rods, vaults, and wooden floors. The era of construction dates to the time when seismic design regulations were largely unknown, making heritage structures potentially vulnerable to earthquake damage. This study presents the seismic performance assessment of the Jesuit College located in the southern part of the Old City of Dubrovnik. A series of field surveys were conducted to qualitatively examine the material composition and obtain geometrical details in part of the Croatian Science Foundation research project IP-2020-02-3531 entitled “Seismic Risk Assessment of Cultural Heritage in Croatia—SeisRICHerCRO”. The structural response is thoroughly investigated by means of a complex finite element model calibrated using the frequencies determined from ambient vibration measurements and material characteristics obtained from the literature review of representative cultural heritage buildings. The seismic performance is evaluated using linear static and response spectrum analysis in accordance with Eurocode 8 guidelines for the demand seismic action level. The numerical analysis indicates several structural components in the building exhibiting high shear stress concentration and exceeding the elastic tensile limit under the demand ground acceleration level. The assessment further reveals substantial out-of-plane bending of vulnerable wall components (identified by local mode shapes) at low peak ground acceleration levels. The stress concentration in numerous structural components leads to the identification of vulnerable zones where retrofitting measures are essentially required.

Unreinforced masonry has been for centuries one of the most widespread constructive techniques for both massive structures and civil buildings (e.g., palaces, hospitals, houses), for the most still standing nowadays. Their future conservation relies on (i) their protection from main natural threats (e.g., earthquakes) and (ii) updating to current functionality and hygrothermal standards. In the former framework, existing masonry buildings proved to have some intrinsic vulnerabilities, depending on composition (units and binder) and structural typologies. Based on experience gathered from seismic events, various retrofitting techniques have been proposed. In such a context, the use of cross-laminated timber (CLT) components is a very promising solution, in terms of compatibility with built heritage and integration of seismic and hygrothermal performances. This paper aims at improving the knowledge of the structural performances of compound timber–masonry interventions by numerical simulations carried out at (i) pier scale and (ii) building full scale via finite element modeling and nonlinear static analyses (pushover). First, a coupled timber–masonry wall was simulated and underwent sensitivity analyses with the properties of both components varying; then, the optimized solution was applied to a case study to assess the intervention benefits, and the results were also cross-checked with those of more traditional interventions (e.g., grout injections). [ABSTRACT FROM AUTHOR]

The paper presents a seismic safety assessment of unreinforced masonry (URM) building using two approaches. The first approach uses the 'Pier Analysis' method, based on the concept of equivalent lateral stiffness, where in-plane and out-of-plane actions are considered independently. The second approach is developed with the program SAP2000, where the linear response is evaluated using continuum 'finite element modelling' (FEM). Both methods are compared to evaluate the safety of wall piers and the differences in the outcomes under combined gravitational and lateral seismic forces. The analysis results showed that few wall elements are unsafe in in-plane and out-of-plane tension. It is also observed that the pier analysis method is conservative compared to FEM, but can be used as a simplified and quick tool in design offices for safety assessment, with reasonable accuracy. To safeguard the URM wall piers under lateral loads, a retrofitting technique is adopted by providing vertical and horizontal belts called splints and bandages, respectively, using welded wire mesh (WWM) reinforcement. The study using the 'Pier Analysis' shows that the lateral load capacity of unsafe URM piers can be enhanced up to 3.67 times and made safe using the applied retrofitting technique. Further, the retrofitting design methodology and recommendations for application procedures to on-site URM buildings are discussed in detail. [ABSTRACT FROM AUTHOR]

Abstract Historical buildings still existing in different parts of the world were constructed with unreinforced masonry and have an acceptable capacity to transmit vertical loading, but they are very vulnerable against horizontal loading induced by earthquakes. In order to protect these buildings belonging to the patrimony of the humanity from this hazard, we need to understand the construction materials, structural elements and loading transmission mechanism. Moreover, to rehabilitate or retrofit them, it is necessary to develop an understanding process of the structure though monitoring and in-situ/laboratory experimental tests to stablish a diagnosis. The structural monitoring campaigns are helpful to investigate the mechanical and dynamic properties of the building. The use of installed thermal cameras and micro-sensors at strategic parts of the historical buildings represent a very interesting and non-destructive option to measure different parameters constantly and for long periods of time. The present paper aims at briefly describing the different involved processes in the monitoring and structural diagnosis of historical buildings which is fundamental in order to preserve them against the effects of earthquakes by means of rehabilitation works and strengthening. Moreover, it is presented a future perspective about non-destructive and non-invasive experimental tests and diagnosis with the use of new technologies. Resumen Los edificios históricos que aún existen en diferentes partes del mundo fueron construidos con mampostería no reforzada y tienen capacidad aceptable para transmitir cargas verticales, pero son muy vulnerables ante cargas laterales inducidas por sismos. Para proteger de esta amenaza a estas edificaciones que forman parte del patrimonio de la humanidad, debemos de entender los materiales constructivos, elementos estructurales y su mecanismo de transmisión de cargas. Para decidir entre rehabilitar o reforzar, se debe de realizar un proceso de entendimiento de la estructura a través de un monitoreo y pruebas experimentales en sitio y en laboratorio que permitan generar un diagnóstico. Los monitoreos estructurales sirven para investigar sus propiedades mecánicas y dinámicas. El uso de cámaras térmicas y micro-sensores en puntos estratégicos de los edificios históricos representan una opción muy interesante y no destructiva para medir diferentes parámetros de forma constante y por largos periodos de tiempo. El presente artículo tiene como objetivo describir de forma puntual los diferentes procesos involucrados en el monitoreo y diagnóstico estructural de edificios históricos que resulta fundamental para poder conservarlos ante los efectos de los sismos por medio de trabajos de rehabilitación y refuerzo. Además, se presenta una perspectiva futura sobre pruebas experimentales y diagnósticos no destructivos ni invasivos con el uso de nuevas tecnologías.

After the Zagreb earthquakes in March 2020, around 25,000 buildings were estimated damaged, most of them being in the historic city center. This fact is not that surprising since most of the city center buildings are unreinforced masonry structures that have not been assessed in quite some time and usually no retrofitting methods were ever applied. The rapid post-disaster assessment began the same day after the first earthquake occurred. Through mostly visual assessment methods, the basic idea is to identify the safety and usability of buildings in general. This type of assessment was also conducted in one of the oldest Croatian cultural institutions, Matica Hrvatska. It is a building of great historical significance and cultural value, as is most of the city center. Accordingly, this building was constructed with no consideration given to seismic events and with the use of traditional materials and building techniques. In the scope of this paper, urgent actions that were taken are shown with problems and challenges that occurred. Furthermore, the decision-making process after an earthquake is elaborated. In addition, a numerical model is developed in 3Muri software for structural modeling. A non-linear static pushover analysis is performed, and possible failure mechanisms are examined. Furthermore, real-life damage is compared to the software results, and a conclusion process of the building's usability is explained. In the end, the results obtained are analyzed and conclusions regarding the efficiency of the used software are drawn. [ABSTRACT FROM AUTHOR]