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The demand for advanced nonlinear time‐history and seismic collapse simulations of old unreinforced masonry (URM) constructions to support informed risk evaluation and mitigation plans is rapidly increasing in the structural engineering profession. On one hand, offering cutting‐edge solutions based on the latest advances is challenging for practitioners, given the reduced timeframe usually available for projects and the specialized knowledge required. On the other hand, researchers frequently face difficulties in accessing old buildings and gathering key data required in complex numerical collapse analysis strategies. In this work, a pragmatic approach for evaluation of the earthquake collapse response of vulnerable old URM churches typical of the Northern Netherlands, now exposed to low‐magnitude induced seismicity due to gas extraction, is presented. To bridge the gap between academic and industry applications, an integrated framework is proposed that combines archival and onsite research, code‐based prescriptions, geometrical characterization and simplified discrete element modeling. Main outcomes include the identification of recurrent damage patterns for five old URM churches erected during the 11th, 13th, 14th, and 19th centuries, representative of key traditional multi‐leaf and cavity‐wall structural types, as well as relevant failure mechanisms and collapsed debris distributions for seismic signals of varying intensities. Produced results constitute a solid foundation of data on which to base the design of ad‐hoc retrofits and development of tailored risk assessment models. This study opens a new line of inquiry while discussing practical challenges and research questions which arose, to be of interest to both applied researchers and structural engineering professionals. [ABSTRACT FROM AUTHOR]

Two roof structures representing vintage unreinforced masonry (URM) building components were subjected to longitudinal pseudo‐static cyclic loading. The overall roof dimensions were 8.94 m (span) by 3.1 m (length), with each roof incorporating a pair of as‐built timber trusses that were retrieved from two demolished URM buildings. Both roofs were tested first with nailed connections representing original construction and then again with connections that included proprietary metal brackets and straps representing a remediation of the original construction. The loading was applied perpendicular to the trusses, hence parallel to the diaphragm purlins. Damage patterns and deformation profiles were used to interpret the mechanics governing the roof behaviour utilizing existing modelling techniques for timber floors. It was found that the roof behaviour was shear‐dominated, akin to the in‐plane response of timber floors. For the direction of applied loading, both roof stiffness and roof strength were governed by the strength of the connections between the trusses and the diaphragm purlin members and the purlin spacing. Consistent with these findings, a method was suggested to estimate the stiffness and strength of similar roof structures that may have different aspect ratios using the results from the tests. A comparison between the various test results showed that implementing upgrades that were focused on the connections significantly improved the roof stiffness and roof strength. [ABSTRACT FROM AUTHOR]

This paper presents the results of a numerical study aimed at assessing the effectiveness of an innovative steel modular retrofit system on improving the in‐plane lateral capacity of unreinforced masonry (URM) load‐bearing structures. The investigated retrofit solution consists of modular steel frames fastened to the external surface of masonry piers through chemical anchors. Distinct element models are built and calibrated against experimental data coming from a series of in‐plane quasi‐static tests performed on piers in both bare and retrofitted conditions. Two different masonry typologies are considered herein: one made up with solid clay bricks and lime mortar, assembled in a header bond pattern, and the other with typical Italian hollow clay units and cement‐lime mortar, arranged in a Flemish bond pattern. A simplified microscale approach, combined with a mesh‐refinement strategy, is adopted to decrease computational demand without losing numerical accuracy. All in‐plane failure mechanisms, such as mortar and unit tensile failures, as well as masonry crushing for high compressive stresses, are included in the developed numerical models. Moreover, a methodology to explicitly account for the contribution of the investigated retrofit in the distinct element method (DEM) framework is presented and discussed. The proposed modeling strategy yielded a good prediction in terms of lateral stiffness, lateral strength, hysteretic response, and crack pattern for unreinforced and strengthened specimens. A novel set of metrics is proposed to quantitatively assess the retrofit performance benefits. [ABSTRACT FROM AUTHOR]

Prior to implementing retrofitting measures for seismic action, it is necessary to evaluate the global capacity of unreinforced masonry (URM) buildings. Even with simplified assumptions, equivalent frame (EF) modeling adequately captures global responses and failure mechanisms in existing buildings, making it a popular modeling strategy among structural engineers. However, macro‐elements employed in the EF modeling of URM walls consider in‐plane (IP) and out‐of‐plane (OP) behaviors separately by decoupling their interaction and require independent verification for OP failure involving limit analysis. Such decoupling of interaction is justifiable if proper wall‐wall/wall‐floor connections and rigid‐diaphragm action of slabs are ensured; however, OP failure is likely a result of inadequate connections. Multiple components of ground motion excitation and plan eccentricity in buildings can activate bidirectional interaction in such circumstances. Due to OP damage, the interaction reduces the full IP strength of a URM wall, resulting in overestimating its lateral capacity. This paper proposes a frame‐like 3D macro‐element incorporating the effect of OP action on the IP shear response of URM piers under static and monotonic lateral loads. Only two parameters modifying IP shear stiffness and capacity are required to account for the interaction. Analytical expressions for the interaction parameters are proposed from a detailed micro‐modeling study. The paper also demonstrates, within the EF modeling, the applicability of the proposed macro‐element for seismic analysis of regular URM shear walls with openings. [ABSTRACT FROM AUTHOR]

Understanding the out‐of‐plane behavior of unreinforced masonry walls is crucial in seismic assessment of existing buildings. Here, the dynamic response of a vertical spanning strip wall, connected to a flexible diaphragm at the top, is investigated. Despite the simplicity of the model, two rocking rigid bodies elastically restrained at the top, the dynamic response is highly nonlinear. This behavior is due to different phenomena: when in motion the system may assume different configurations, with the transition between them due either to impacts or crack opening caused by ground acceleration. An analytical model capable to capture the complex dynamic response of the system is implemented. The equations of motion are first derived, using variational methods, then the events that the system can undergo during motion are studied. Finally, in order to show the potential of the model, some numerical exemplifications are presented applying an earthquake record and a sine pulse to the system. [ABSTRACT FROM AUTHOR]

Plane‐stress and shell macromodels are often preferred to analyze masonry structures because of their numerical efficiency. However, they often misestimate the hysteretic behavior of the structures. Additionally, due to the nature of smeared cracks, the cracks may be diffused. This article proposes a new orthotropic model, which focuses on the cyclic, nonlinear behavior of brick masonry structures. The model adopts a total‐strain based rotating crack approach. It describes tensile and compressive failure in the rotating principal directions, while including indirectly shear failure through an internal iterative algorithm. Two distinctions are made regarding the tensile postpeak and unloading/reloading behavior based on the crack orientation at crack initiation: a steep softening branch and secant unloading are adopted when the crack angle corresponds to in‐plane flexural failure, and a softening branch and bilinear unloading are adopted when the crack angle corresponds to diagonal shear failure. Bilinear unloading/reloading is adopted in compression, resulting in a cyclic behavior resembling shear. The constitutive model was implemented in a finite element software and validated against experimental results. The numerical simulations reproduced well the experimental outcomes in terms of envelope load‐displacement curve and hysteretic behavior, while simultaneously they resulted in localized damage, representative of the experimental crack patterns. [ABSTRACT FROM AUTHOR]

It is well established that unreinforced masonry (URM) buildings develop damage‐forming collapse mechanisms during high‐intensity earthquakes, with these mechanisms exhibiting large rocking displacements before collapsing. The Discrete Element Method (DEM) of analysis can realistically capture phenomena that involve large movements of elements, resulting in the technique being ideal for simulating the collapse of URM building elements. Consequently, extensive research using DEM to analyse the seismic response of URM buildings and building components has recently been published. However, the variety of reported damping approaches that have apparently led to DEM results that successfully replicate physical observations underscores the need for consistent guidance related to the assignment of damping factors. The Rayleigh damping distribution model implemented in the DEM software 3DEC was used to study the differences between mass proportional (MP) and stiffness proportional (SP) damping configurations. After reviewing phenomena that need to be damped and previous works where damping was implemented, the capabilities and drawbacks of the time‐efficient MP damping configuration were studied and the results compared to simulations with SP damping. When considering numerical simulations that incorporated MP damping and led to results that were seemingly well‐matched to experimental tests, it was found that the apparent robustness of decisions pertaining to the adopted input parameters was deceptive in most cases. Consequently, SP damping was recommended for all DEM rocking simulations, even though MP damping could be used with satisfactory accuracy in certain situations discussed herein. A pragmatic relationship between both damping strategies was proposed. [ABSTRACT FROM AUTHOR]

In the seismic analysis of unreinforced masonry (URM) structures, the modeling of out‐of‐plane (OOP) modes and their mechanical interaction with in‐plane (IP) loaded components are typically neglected when using simplified numerical methods. Although this may result in unconservative predictions, the high computational expense entailed by more refined approaches is often prohibitive for applied researchers and practitioners. To overcome these limitations, the demonstrated capabilities of a recently developed low‐cost Macro‐Distinct Element Model (M‐DEM) to simulate IP and OOP modes are extended in this work towards the modeling of IP/OOP interaction and combined failure mechanisms of URM assemblies. In the M‐DEM framework, shear and flexural damage are accounted for by zero‐thickness interface spring layers, whose layout is determined a priori as a function of the masonry texture, while crushing failure is modeled through homogenized finite element macro‐blocks. To adapt and validate this M‐DEM scheme to model IP/OOP interaction, past experiments on full‐scale C‐, U‐, and I‐shaped URM specimens tested under quasi‐static loading were simulated. The shake‐table response of a full‐scale C‐shaped URM assembly with openings was also numerically simulated up to collapse, representing a major improvement over previous macro‐element methods. After the comparison with experimental tests, a parametric investigation of the response of reference URM walls under combined IP/OOP actions was conducted, and the influence of previous IP damage on one‐ and two‐way OOP bending capacity is quantified. This aspect, despite being widely identified as of relevant interest, has only been marginally investigated in previous research, both experimentally and numerically. [ABSTRACT FROM AUTHOR]

Cyclic shear tests on walls made of clay block masonry Cyclic shear tests are a common method to assess the load‐bearing capacity and the deformation behaviour of walls under dynamic loads in the horizontal direction, such as those that occur during earthquakes. In the presented work, cyclic shear tests on 36 walls made of different types of masonry are described, the test results are shown and compared with calculated resistances according to Eurocode 6. After a list of the building materials used, the materials used and their dimensions are given for all examined walls. This is followed by a description of the experimental setups used at the institutes UTCB in Bucharest and ZAG in Ljubljana. The main part is the presentation of the measured values regarding achievable loads and drift values, as well as the determination of a bilinear approximation for each test. The envelope curves of the hysteresis loops of all experiments are then shown and compared. Finally, a comparison of the test results to calculated resistances according to Eurocode 6 is shown. With these investigations it could be shown that walls made of masonry have large drift capacities and that the assessment with the models of the Eurocode 6 delivers very realistic results. Furthermore, it could be shown, that conservative results are achieved when the resistance of masonry from concrete‐filled blocks is calculated with a composite stone strength, especially for walls with a higher degree of reinforcement. [ABSTRACT FROM AUTHOR]

Summary: The results of an investigation of the probability of earthquake damage to nonstructural unreinforced masonry (URM) components are presented. The components include parapets, chimneys, and out‐of‐plane loaded facades typical of low‐rise pre‐1940 construction in Australia and New Zealand. The study is based on a street survey of component geometry, in situ data on material strength, and simplified mechanical models. Uncertainties in capacity and demand were quantified based on, respectively, stochastic and deterministic approaches. The damage probabilities were compared with relevant guidelines and empirical damage data from three earthquakes. The study established a link between the qualitative damage states reported in existing guidelines and the quantitative URM component damage states. While some median damage state thresholds correlated well with the data from the guidelines, a larger dispersion value was found in the current study due to the large variations in component properties. Comparisons with empirical data suggest that the developed fragility data provide a realistic estimate of nonstructural component damage that occurred in similar buildings, with a reasonable level of conservatism. The outcome is useful in rapid assessment of the seismic risks due to nonstructural component collapse in URM precincts. [ABSTRACT FROM AUTHOR]

Summary: For seismic analysis of unreinforced masonry (URM) buildings characterized by a box‐like behavior, a widely accepted model is based on the equivalent frame idealization of walls. The equivalent frame model uses 1D elements to represent the vertical piers and horizontal spandrels which are connected by rigid nodes. The mechanical characterization of the elements is one of the crucial aspects to predict reasonably the building seismic behavior. Through the comparison with pseudo‐static and dynamic experimental tests performed on two‐story full‐scale buildings, this paper validates the frame modeling in the OpenSees framework, which includes a fiber‐section force‐based beam element for the axial‐flexural behavior, coupled with a cyclic shear‐deformation phenomenological law. [ABSTRACT FROM AUTHOR]

Summary: The in‐plane capacity of unreinforced masonry (URM) elements may vary considerably depending on several factors, including boundary conditions, aspect ratio, vertical overburden, and masonry texture. Since the overall system resistance mainly relies on the in‐plane lateral capacity of URM components when out‐of‐plane modes are adequately prevented, the structural assessment of URM structures could benefit from advanced numerical approaches able to account for these factors simultaneously. This paper aims at enhancing and optimising the employment of the distinct element method, currently confined to the analysis of local mechanisms of reduced‐scale dry‐joint blocky assemblies, with a view to simulate the experimentally observed responses of a series of URM full‐scale specimens with mortared joints subjected to quasi‐static in‐plane cyclic loading. To this end, a mesoscale modelling approach is proposed that employs a simplified microscale modelling approach to effectively capture macroscale behaviour. Dynamic relaxation schemes are employed, in combination with time, size, and mass‐scaling procedures, to decrease computational demand. A new methodology for numerically describing both unit, mortar and hybrid failure modes, also including masonry crushing due to high‐compression stresses, is proposed. Empirical and homogenisation formulae for inferring the elastic properties of interface between elements are also verified, enabling the proposed approach to be applied more broadly. Using this modelling strategy, the interaction between stiffness degradation and energy dissipation rate was accounted for numerically. Although the models marginally underestimate the energy dissipation in the case of slender piers, a good agreement was obtained in terms of lateral strength, hysteretic response, and crack pattern. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the design of basement walls subjected to lateral earth pressure. The current simplified calculation method according to DIN EN 1996‐3/NA only covers active earth pressure, which is the lower limiting value of the earth pressure. Designing according to DIN EN 1996‐1‐1/NA, higher coefficients of earth pressure (like earth pressure at rest) can be considered, with an additional verification of the shear resistance being necessary. This paper presents a theoretical model, which forms the basis for an analytical derivation of the loadbearing capacity, and explains the required minimum values of the acting normal force to ensure sufficient resistance to cover bending and shear. Based on these results, a simplified equation is proposed for the determination of the required minimum normal force, based on the design according to DIN EN 1996‐3/NA and providing identical values in case of an earth pressure coefficient of 1/3. The required minimum load resulting from this approach fulfils the described requirement to cover bending and shear. The presented solution is verified and the conditions for application are defined. Finally, the minimum required normal forces are evaluated and tabulated for common cases relevant to building practice. [ABSTRACT FROM AUTHOR]

Summary: The response of calcium silicate unreinforced masonry construction to horizontal cyclic loading has recently become the focus of experimental and numerical research, given its extensive use in some areas of the world that are now exposed to induced earthquakes (eg, north of the Netherlands). To assess the seismic behaviour of such construction, a relatively wide range of modelling methodologies are available, amongst which the discrete elements approach, which takes into account the intrinsic heterogeneity of a brick‐mortar assembly, can probably be deemed as the most appropriate computational procedure. On the other hand, however, since discrete elements numerical methods are based on a discontinuum domain, often they are not able to model every stage of the structural response adequately, and because of the high computational burden required, the analysis scale should be chosen carefully. The applied element method is a relatively recent addition to the discrete elements family, with a high potential for overcoming the aforementioned limitations or difficulties. Initially conceived to model blast events and concrete structures, its use in the earthquake engineering field is, of late, increasing noticeably. In this paper, the use of the applied element method to model the in‐plane cyclic response of calcium silicate masonry walls is discussed and scrutinised, also through the comparison with experimental results of in‐plane cyclic shear‐compression tests on unreinforced masonry walls. [ABSTRACT FROM AUTHOR]

The structural stability of unreinforced masonry (URM) walls has to be guaranteed not only under static (permanent and live) loads but also under earthquake loads. Loads transverse to the plane (out-of-plane) often have a decisive influence on the load-bearing capacity. In practical applications, simplified methods from codes, guidelines and literature are often used to analyse and evaluate the out-of-plane capacity of load-bearing and non-load-bearing URM walls. The results of these simplified methods can be significantly conservative and inaccurate since essential influencing effects are neglected. For many existing buildings, the simplified methods underestimate the capacity, which leads to cost-intensive retrofitting and strengthening measures or complete replacement by other wall systems. In order to realistically estimate the out-of-plane capacity, parameters such as wall geometry, boundary conditions, vertical loads and especially dynamic effects (e.g. inertia forces) have to be taken into account. In this paper, non-linear time history simulations are presented to investigate the influence of these effects. The numerically determined maximum acceptable earthquake acceleration is compared with results from simplified analysis models. The comparison shows that the out-of-plane capacity is significantly higher than the values predicted by simplified models. Finally, several initial experimental seismic tests conducted on the shaking table of the TU Kaiserslautern are presented, together with the planned extensive experimental test program on the out-of-plane capacity of masonry walls. [ABSTRACT FROM AUTHOR]

An analytical model describing the flexural response of vertically spanning out-of-plane loaded unreinforced masonry walls is presented in this paper. The model is based on the second-order Euler-Bernoulli beam theory and captures important characteristics of the out-of-plane response of masonry walls that have been observed in experimental tests and from numerical studies but for which an analytical solution was still lacking: the onset and the evolution of cracking, the peak strength of the out-of-plane loaded walls, and the softening of the response due to P−Δ effects. The model is validated against experimental results, and the comparison shows that the model captures both the prepeak and postpeak response of the walls. From the analytical model of the force-displacement curve, a formula for the maximum out-of-plane strength of the walls is derived, which can be directly applied in engineering practice. [ABSTRACT FROM AUTHOR]

Dedicated to University Prof. Dr.-Ing. Carl-Alexander Graubner for his 60th birthday The simplified calculation methods for unreinforced masonry structures given in DIN EN 1996-3/NA are an easily applicable design standard for an efficient and fast verification of the resistance of mainly vertically loaded masonry walls. However, the design rules are not based on mechanical models. Instead, they are empirical approaches for a simplified estimation of the load bearing capacity. For this reason, the range of application of DIN EN 1996-3/NA is limited by several conditions to ensure a sufficient safety of this design procedure. With regard to extending the conditions for application, extensive comparative calculations were carried out. Thereby, considering clearly defined boundary conditions, the load bearing capacity according to DIN EN 1996-3/NA was compared to that according to DIN EN 1996-1-1/NA. It was the aim of this comparison to identify load bearing reserves of the simplified calculation methods to point out potential for an extension regarding the maximum permissible clear wall height and the slab span. As a result, it can be stated, that an increase of the maximum wall height up to 6.0 m and the maximum slab span of 7.0 m is possible in certain cases. [ABSTRACT FROM AUTHOR]

Seismic safety verification can be performed by maintaining constructive rules or by calculation. Verification by calculation can be performed with a linear simplified or linear multi-modal response spectrum analysis. Alternatively, a non-linear quasi-static verification is also possible according to DIN EN 1998-1, which was not available in DIN 4149. In this article, the non-linear quasi-static earthquake verification according to DIN EN 1998-1 is presented in practice, using the example of a building in Mittenwald/Germany. The verification has been checked and accepted by an independent building supervision report. [ABSTRACT FROM AUTHOR]

Seismic assessment of existing unreinforced masonry buildings represents a current challenge in structural engineering. Many historical masonry buildings in earthquake regions were not designed to withstand seismic loading; thus, these structures often do not meet the basic safety requirements recommended by current seismic codes and need to be strengthened considering the results from realistic structural analysis. This paper presents an efficient modelling strategy for representing the nonlinear response of unreinforced masonry components under in-plane cyclic loading, which can be used for practical and accurate seismic assessment of masonry buildings. According to the proposed strategy, generic masonry perforated walls are modelled using an equivalent frame approach, where each masonry component is described utilising multi-spring nonlinear elements connected by rigid links. When modelling piers and spandrels, nonlinear springs are placed at the two ends of the masonry element for describing the flexural behaviour and in the middle for representing the response in shear. Specific hysteretic rules allowing for degradation of stiffness and strength are then used for modelling the member response under cyclic loading. The accuracy and the significant potential of the proposed modelling approach are shown in several numerical examples, including comparisons against experimental results and the nonlinear dynamic analysis of a building structure. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

For the structural analysis of the bending compression zone of masonry building elements, which are loaded under bending compression parallel to the bed joints, the longitudinal compressive strength of the masonry is required. According to the code, this value has until now been determined in laborious tests on masonry building elements or calculated analogously to the approach for the determination of the compressive strength perpendicular to the bed joints. In such a way, the actual failure mechanisms of masonry under compression loading parallel to the bed joints and relevant influential parameters for the longitudinal compressive strength however remain unconsidered. The article presents a proposal for the determination of minimum values of the longitudinal compressive strength of masonry in a simplified form for structural design purposes, which include consideration of both the relevant failure cases and also the significant influential parameters. [ABSTRACT FROM AUTHOR]

In modern unreinforced masonry buildings with stiff RC slabs, walls of the top floor are most susceptible to out-of-plane failure. The out-of-plane response depends not only on the acceleration demand and wall geometry but also on the static and kinematic boundary conditions of the walls. This paper discusses the influence of these boundary conditions on the out-of-plane response through evaluation of shake table test results and numerical modelling. As a novum, it shows that the in-plane response of flanking elements, which are orthogonal to the wall whose out-of-plane response is studied, has a significant influence on the vertical restraint at the top of the walls. The most critical configuration exists if the flanking elements are unreinforced masonry walls that rock. In this case, the floor slabs can uplift, and the out-of-plane load-bearing walls loose the vertical restraint at the top. Numerical modelling confirms this experimentally observed behaviour and shows that slab uplift and the difference in base and top excitation have a strong influence on the out-of-plane response of the walls analysed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The verification of safety against buckling of unreinforced masonry walls according to the accurate design procedure of EN 1996-1-1 Appendix G is based on semi-empirical approaches, which do not always realistically describe the load-bearing behaviour. This statement is also supported by an objection of the country Denmark concerning the load capacity function which is regulated in Appendix G. Using new findings about the effects of non-linear material behaviour in case of stability failure this article investigates fundamental questions about the buckling behaviour of masonry walls and transfers these into a simple practical structural design proposal. As a result, the load capacity function can be considerably simplified, the influence of creep can be integrated and the number of input parameters can be reduced. [ABSTRACT FROM AUTHOR]

This article presents a new mechanical model for the non-linear force-displacement response of unreinforced masonry (URM) walls developing a flexural rocking mode including their displacement capacity. The model is based on the plane-section hypothesis and a constitutive law for the masonry with zero tensile strength and linear elastic behaviour in compression. It is assumed that only the compressed part of the wall contributes to the stiffness of the wall and therefore the model accounts for a softening of the response due the reduction of the effective area. Stress conditions for limit states are proposed that characterise the flexural failure. The new model allows therefore linking local performance levels to global displacement capacities. The limit states criteria describe the behaviour of modern URM walls with cement mortar of normal thickness and clay bricks. The model is validated through comparison of local and global engineering demand parameters with experimental results. It provides good prediction of the effective stiffness, the force capacity and the displacement capacity of URM walls at different limit states. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Masonry walls constructed with lightweight AAC blocks and thinlayer mortar meet the increasingly strict requirements of energy efficiency and sustainability. In this sense, they represent an excellent solution for modern buildings, not only for external cladding but also as loadbearing elements. Despite the possible advantages of using lightweight AAC masonry, a specific assessment of its seismic performance is mandatory in order to set design recommendations allowing to reach safety levels consistent with those required for other masonry types complying with EN 1998 standard requirements. A comprehensive study on the seismic performance of unreinforced masonry buildings made of lightweight AAC was carried out in an integrated experimental-numerical approach. The experimental campaign provided the necessary information to setup a reliable numerical model to be extensively used to assess the seismic performance of a number of prototype AAC masonry buildings with different characteristics, by means of both linear and nonlinear static (pushover) analysis. The results of this systematic numerical assessment were eventually used to draft design recommendations, to set parameters (behaviour factors) to be used in linear analysis and to calibrate rules for simple buildings. [ABSTRACT FROM AUTHOR]

SUMMARY This paper presents the results on shaking table tests of half-scale brick walls performed to investigate the effectiveness of newly developed Cu-Al-Mn superelastic alloy (SEA) bars in retrofitting of historical masonry constructions. Problems associated with conventional steel reinforcing bars lie in degradation of stiffness and strength, or pinching phenomena, under cyclic loading, and presence of large residual cracks in structures during and after intense earthquakes. This paper attempts to resolve the problems by applying newly developed Cu-Al-Mn SEA bars, characterized by large recovery strain, low material cost, and high machinability, as partial replacements for steel bars. Sets of unreinforced, steel reinforced, and SEA-reinforced specimens are subjected to scaled earthquake excitations in out-of-plane direction. Whereas steel-reinforced specimens showed large residual inclinations, SEA-reinforced specimens resulted in stable rocking response with slight residual inclinations. Corresponding nonlinear finite element (FE) models are developed to simulate the experimental observations. The FE models are further used to examine the sensitivity of the response with respect to the variations in experimental conditions. Both the experimental and numerical results demonstrate the superiority of Cu-Al-Mn SEA bars to conventional steel reinforcing bars in avoiding pinching phenomena. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]