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This work aims estimating seismic losses in residential-reinforced concrete buildings, highlighting the influence of infills and services. First, the mechanical-based “POST”-method is used to perform simplified (nonlinear static) structural analyses, in the “shear-type” building hypothesis. Then, drift-based fragility curves and repair cost analysis, specific for infills and services, are used to obtain expected damage and losses. Lastly, the whole proposed loss assessment methodology is applied to a wide building stock struck by L’Aquila (Italy) 2009-earthquake and damaged to infills. The numerical-versus-observed comparison of damage scenario and seismic losses allows a promising validation of the procedure.

Funder: Maratona da Saúde, Funder: Royal Society Wolfson, Funder: Wellcome; Id: http://dx.doi.org/10.13039/100010269, Since the discovery of lysosomes more than 70 years ago, much has been learned about the functions of these organelles. Lysosomes were regarded as exclusively degradative organelles, but more recent research has shown that they play essential roles in several other cellular functions, such as nutrient sensing, intracellular signalling and metabolism. Methodological advances played a key part in generating our current knowledge about the biology of this multifaceted organelle. In this review, we cover current methods used to analyze lysosome morphology, positioning, motility and function. We highlight the principles behind these methods, the methodological strategies and their advantages and limitations. To extract accurate information and avoid misinterpretations, we discuss the best strategies to identify lysosomes and assess their characteristics and functions. With this review, we aim to stimulate an increase in the quantity and quality of research on lysosomes and further ground-breaking discoveries on an organelle that continues to surprise and excite cell biologists.

Lysosomal storage disorders characterized by altered metabolism of heparan sulfate, including Mucopolysaccharidosis (MPS) III and MPS-II, exhibit lysosomal dysfunctions leading to neurodegeneration and dementia in children. In lysosomal storage disorders, dementia is preceded by severe and therapy-resistant autistic-like symptoms of unknown cause. Using mouse and cellular models of MPS-IIIA, we discovered that autistic-like behaviours are due to increased proliferation of mesencephalic dopamine neurons originating during embryogenesis, which is not due to lysosomal dysfunction, but to altered HS function. Hyperdopaminergia and autistic-like behaviours are corrected by the dopamine D1-like receptor antagonist SCH-23390, providing a potential alternative strategy to the D2-like antagonist haloperidol that has only minimal therapeutic effects in MPS-IIIA. These findings identify embryonic dopaminergic neurodevelopmental defects due to altered function of HS leading to autistic-like behaviours in MPS-II and MPS-IIIA and support evidence showing that altered HS-related gene function is causative of autism., Lysosomal storage disorders, characterized by altered metabolism of heparan sulfate, cause autistic symptoms followed by dementia in children. Here, the authors show that embryonic dopaminergic neurodevelopmental defects due to altered function of heparan sulfate cause autistic behaviours in mice.

The analysis of the behaviour of masonry infills under out-of-plane (OOP) and in-plane (IP) loading is paramount to correctly assess the seismic performance of reinforced concrete (RC) frames. A very important issue about this topic is certainly the IP/OOP interaction, namely the analysis of how the IP damage, which affects infills during earthquakes, can influence their OOP behaviour (and vice-versa). Some studies about this topic were developed in the last years; nevertheless, only a dozen of tests currently exists in the literature to experimentally explore this key issue. This work first presents an experimental campaign carried out on square infill walls in RC frames to investigate about the OOP behaviour of the masonry infills, and about the IP/OOP interaction. On the whole, four specimens have been tested under OOP monotonic loading. Three of them have been first damaged under cyclic IP actions, with different extent; the remaining one, used as a reference, was tested under OOP loading only. The experimental campaign is described in detail in terms of specimens’ characteristics, material properties, adopted setup and instrumentation layout. The experimental results are analysed in terms of IP and OOP force-displacement responses, vertical arch strength contribution evolutions, and damage state evolutions, and compared with prediction proposals from the literature. Then, the influence of the infill aspect ratio (width (w)-to-height (h) ratio) on the IP/OOP interaction is investigated by means of the comparison between data presented herein (collected on infills with w/h = 1) and a companion experimental campaign previously performed on nominally identical infills except that for the aspect ratio of the specimens (in that case, higher than the unit). It has been observed that under given IP drift levels, square infills presented lower IP damage levels with respect to rectangular infills (with w/h > 1), thus generally producing a less pronounced detrimental effect of the IP imposed drift on the OOP strength. Nevertheless, none of the predictions from literature takes into account the role of the aspect ratio on the IP/OOP interaction, generally resulting in conservative predictions, to be improved in future works.

The seismic assessment and retrofit of non-conforming Reinforced Concrete (RC) buildings still represent a challenge for researchers and practitioners worldwide due to several aspects. On one hand, low standards RC buildings typically present some failure typologies very different from newly designed buildings, and such failure modes should be properly modelled for a reliable seismic performance assessment. On the other hand, retrofitting strategies should be chosen carefully looking both at safety at collapse and at seismic capacity at less severe performance levels, considering nonstructural components as well. Masonry infills, typically defined as non-structural components despite their structural role, significantly affect the seismic behavior of existing RC buildings, especially at low-medium intensity measures. Therefore, when the seismic performance of as-built or retrofitted RC buildings is assessed, their contribution should be considered. In this work, a preliminary analysis of two 4-storey low-standard RC buildings, different for design typology, is presented, based on static nonlinear analyses. First, case-study buildings, representative of Italian pre-70 residential buildings, have been assessed in their “bare” configuration (without infills), as common in design practice, in a code-based approach (according to Italian code). Based on the asbuilt assessment outcomes, their retrofit has been designed by means of two main strategies: (1) the complete resolution of all the shear failures (in columns or joints), if any; (2) the reduction of the displacement demand by means of RC column jacketing, when necessary, along with the resolution of shear failures (as for the previous strategy). Then, both the as-built and retrofitted building configurations have been modelled and analysed explicitly considering the presence of infills and shear-critical elements. Fragility curves have been obtained at different Damage States according to European Macroseismic Scale EMS-98, considering record-to-record variability, and compared to each other. Remarks about the choice among strengthening strategies are carried out, based on these outcomes and on a preliminary estimation of the expected mean annual losses for the investigated buildings.

In this study a dedicated framework for seismic losses estimation in Reinforced Concrete buildings is presented, taking advantage of a simplified analytical structural analysis, a dedicated drift-based fragility curves and a specific repair cost analysis. To this aim, the mechanically based “Pushover on Shear Type model” (POST)-method, already know in the literature [1] for simplified structural analysis, has been integrated herein to obtain expected losses due to earthquakes for infilled RC buildings. On the other hand, the thoroughly cost analysis dedicated to only masonry infill panels and services (electric and plumbing system, sanitary equipment, floors, etc.) restoration presented in [2] has been used to develop an integrated formulation for loss estimation in Reinforced Concrete buildings. The application to a wide dataset of buildings struck by L’Aquila (Italy) 2009-earthquake is used as testbed for large-scale applications. In fact, the comparison with actual damage distribution and repair cost provides a useful validation of the whole framework, from structural analysis to loss prediction.

Worldwide, substandard Reinforced Concrete (RC) buildings with unreinforced beam-column joints are widespread also in seismic prone areas. In this work, the performed experimental campaign related to cyclic tests on exterior unreinforced joints is presented. The main investigated parameters are related to the joint aspect ratio, the design typology for the beam-column sub-assembly, the beam longitudinal reinforcement amount, and the longitudinal reinforcement typology (plain or deformed bars). The effect of such parameters on the seismic response is investigated. Furthermore, a modelling proposal for exterior unrein-forced joints is proposed, depending on the reinforcement typology. The model is numerically efficient for extensive nonlinear analyses, based on experimental tests, easily implementable in common software platforms, and compatible with whatever modelling strategies adopted for the other RC members. The validation of such model is also performed through numerical-versus-experimental comparisons at the scale of the beam-column sub-assembly and at the scale of a whole frame. / Edifici esi-stenti in c.a. caratterizzati dalla presenza di nodi trave-colonna non staffati sono estremamente diffusi in tutto il mondo, anche in zone altamente sismiche. In questo articolo, si presenta la compagna sperimentale relativa a nodi non staffati esterni sotto azione ciclica realizzata dagli autori per analizzare l’effetto sulla risposta di nodo di parametri come il rapporto di forma del pannello nodale, la tipologia di progettazione, il quantitativo di armatura longitudinale nella trave, la tipologia di armature (barre lisce o nervate). Inoltre, si presenta una proposta di modellazione di nodo, dipendente dalla tipologia di armatura, che sia numericamente efficiente per analisi non lineari, basato su dati sperimentali, facilmente implementabile in comuni software e compatibile con ogni scelta di modellazione per gli elementi in c.a. adiacenti. Il modello è infine validato con confronti con dati sperimentali sia a livello di sub-assemblaggio che di intero telaio.

Experimental works in literature have paid proper attention to the seismic response of hollow circular piers only quite recently, despite their widespread use in existing bridges. Herein, experimental cyclic tests on two scaled reinforced concrete piers with hollow circular cross-section, representative of typical existing Italian bridges, are carried out. Design criteria, adopted setup, experimental response, and damage evolution are discussed. A focus on shear–critical piers is performed, collecting an experimental database of tests from literature. The more specific existing shear strength models are compared with the collected data. Model by Ranzo and Priestley [2001] has finally shown promising results.

Earthquakes that have occurred in the last twenty years in the Mediterranean area have had significant economic and social impacts. Most of the economic losses of reinforced concrete (RC) frames was due to nonstructural component damage, particularly masonry infills and partitions. Therefore, the seismic behaviour of masonry infills should be reliably characterized. The main goals of this study for a more reliable loss estimation for infilled RC frames are: (i) the analysis of the inter-story drift ratio (IDR) capacity at given damage states (DSs) with the aim to define drift-based fragility functions and (ii) analyse direct losses due to infill damage following seismic events. First, a database of experimental tests performed on 1-bay, 1-story scaled RC frames infilled with clay bricks or concrete blocks is collected. Drift-based fragility curves are obtained, which depend on the infill brick materials and properties. Then, the drift capacity threshold at each DS is correlated to the in-plane response of the infill panel to directly quantify the relationship that exists among them. The influence of openings on drift capacities is also evaluated. Then, seismic losses related to infills are computed, providing expected monetary losses depending on the infill typology. The required reparation activities and their costs are also listed. The bearing of each activity and cost at each DS is explicitly evaluated. Additionally, loss functions that directly depend on IDR demand are provided, thus fusing together the damage analysis and loss analysis. Finally, a simplified formulation for loss functions is proposed for a simple, practice-oriented loss calculation.

Most of the existing Reinforced Concrete (RC) bridges were designed before the recent advancements in earthquake engineering and seismic codes. The performance assessment of these bridges is, therefore, a crucial issue for seismic safety of bridge infrastructures and estimation of losses due to seismic events. Despite the seismic assessment of columns with solid cross-section in ordinary buildings may be considered as quite comprehensive, a similar conclusion cannot be drawn for shear-critical hollow core piers, widespread in existing bridge structures. The present work aims at contributing to the investigation about the response of RC piers with hollow rectangular cross-section under cyclic loading. The main goal of the study is the definition of a comprehensive and practice-oriented modelling approach for the assessment of seismic response of RC hollow rectangular piers, able to account for all the deformability contributions, and, particularly, able to reliably predict drift-capacity at shear failure and subsequent degrading stiffness. A three-component model, accounting for flexural flexibility, shear flexibility and slippage of rebars is adopted. The shear capacity assessment is dealt with more in details. A proper experimental database is collected, made up of cyclic tests on hollow rectangular piers failing in shear, with or without yielding of longitudinal reinforcing bars. A new empirical formulation for the assessment of the displacement capacity at shear failure, specifically for the investigated structural elements, is calibrated. The degrading stiffness also is empirically calibrated to completely define the degrading shear response. Finally, the proposed numerical model is validated through the comparison with the experimental results carried out by the Authors (also in terms of local deformability contributions) and with test results collected from literature, proving that it can be a simple and reliable tool for the seismic assessment of existing shear-critical bridge piers.

The seismic performance of existing Reinforced Concrete (RC) frames is significantly influenced by the behaviour of beam-column intersections, especially in non-conforming buildings with poor structural details and completely unreinforced joints. In literature, a very limited number of studies deals with specimens reinforced with plain hook-ended longitudinal bars, widespread in Italian and Mediterranean building stock, or with the analysis of local aspects, such as the experimental evaluation of joint shear strains. The almost totality of the models proposed in literature for simulating the cyclic behaviour of RC joints was developed and calibrated by means of tests performed on elements with deformed bars, and, thus, these models may be not adequate for elements with hook-ended plain bars, especially due to the peculiarities in terms of failure mode and interaction mechanisms between concrete and steel. This study analyses the experimental cyclic behaviour of four full-scale exterior unreinforced RC beam-column joints with plain reinforcing bars in beams and columns, which differ for joint aspect ratio and beam longitudinal reinforcement ratio. First, experimental global and local responses of such tests – including energy dissipation capacity and observed damage evolution – are analysed. The main deformation mechanisms ascribable to the joint – namely rotation at the interface between beam/columns and joint, and shear deformation of the joint panel – are experimentally evaluated to provide a realistic support for the numerical modelling of this typology of beam-column joints. Then main joint shear strength models existing in codes and literature are compared with the experimental results. Finally, the numerical modelling of the specimens is carried out under monotonic loading to reproduce the envelope of the experimental responses. The joint panel constitutive parameters are defined to reproduce the experimental joint shear stress-strain relationships. Additionally, modelling of bond-slip is particularly taken into account due to the poor quality of steel-concrete interaction in the specific case of plain reinforcing bars.

O colapso para fora-do-plano das paredes de alvenaria de enchimento em edifícios existentes de betão armado devido a sismos representa um assunto de extrema importância no que toca à salvaguarda de vidas e estimativa de perdas económicas. Este trabalho apresenta os resultados de uma campanha experimental relativa à avaliação de soluções de reforço desenhadas para mitigar ou evitar o seu colapso. As técnicas de reforço investigadas basearam-se na aplicação de uma camada muito fina de uma argamassa de elevada ductilidade e rede de armação em fibra de vidro com diferentes tipos de ancoragem ao pórtico de betão armado envolvente. As propriedades mecânicas dos materiais adotados, o setup experimental e o procedimento de ensaio serão apresentados ao longo do artigo. Detalhes relativos à eficiência de cada solução de reforço são fornecidos e comparados por forma a dar suporte para a seleção da melhor estratégia para investigações mais detalhadas e futuras aplicações. Out-of-plane (OOP) collapse of infill masonry walls in existing reinforced concrete (RC) buildings due to earthquakes represents a paramount issue for life safety and seismic economic loss estimation. Few studies from literature deal with this topic, particularly regarding possible strengthening strategies to prevent the infills' OOP collapse. This work presents the first results of a proper experimental campaign about the assessment of different strengthening solutions designed to mitigate or avoid the out-of-plane collapse of masonry infills in existing RC buildings. The investigated strengthening techniques were based on the application of a very thin high-ductility mortar plaster and glass fibre-reinforced polymer nets with different types of anchorage to the surrounding RC frame. Each specimen was built with horizontal hollow clay bricks and was tested through the application of a semi-cyclic OOP displacement pattern by means of uniformly distributed small pneumatic jacks. Mechanical properties of the adopted materials, test setup and procedure are described herein. Tests results are presented and commented in terms of OOP force-displacement responses and damage evolution during the test. Details about the effectiveness of each retrofitting solution are provided and compared to support the selection of the best strategy for further investigations and future applications.

The estimation of direct and indirect losses due to earthquakes is a key issue in the Performance Based Earthquake Engineering framework. In commonly adopted loss computation tools, no specific data related to masonry infill panels, widespread in moment-resisting-frame residential buildings, are available to perform a probabilistic assessment of losses. To fill this gap, specific fragility and loss functions have been recently proposed in the last years. To assess their validity and estimate the relevance of the repair costs due to infills after earthquakes with respect to the total reconstruction process, the present work analyses the Reinforced Concrete residential buildings with masonry infills struck by the 2009 L’Aquila (Italy) earthquake, focusing on the dataset of “lightly„ damaged buildings, where only damage to masonry infills occurred. Based on available data related to these buildings, the observed damage scenario after L’Aquila earthquake is first obtained. The repair costs for infills are estimated given this damage scenario. The resulting estimated repair costs are then compared with the actual repair costs presented in the available literature. The percentage influence of infills on the total repair costs due to earthquakes for residential buildings is lastly computed, resulting on average equal to the fifty percent.

The response of unreinforced beam-column joints represents a key issue in seismic vulnerability and fragility assessment of existing Reinforced Concrete (RC) buildings. Within this framework, a great attention is focused on the investigation of the experimental response of unreinforced joints strengthened with different technologies, based on traditional or innovative materials, and with different complexity/cost. In this study, an experimental investigation of the response of external RC beam-column joints is presented. Four specimens are tested, namely one as-built, unreinforced (without stirrups in the joint panel region) specimen, one reinforced with a codecompliant amount of transverse reinforcement (stirrups) in the joint panel – for reference and comparison purposes, and two specimens strengthened with the application of prestressed steel strips as external transverse reinforcement, using the CAM® technology with two different layouts characterized by a different complexity of installation. The response of the unreinforced specimen was controlled by joint panel failure following beam yielding, whereas the specimen reinforced with code-compliant joint stirrups showed a ductile behaviour, controlled by beam flexural failure. The response of the strengthened specimens demonstrated the effectiveness of the adopted technology, that led to a ductile response – as for the specimen reinforced with stirrups – or to a joint panel failure following beam yielding – as for the as-built unreinforced specimen, but with a higher global ductility. The experimental results are reported and discussed, in terms of global response of the sub-assemblage and of observed damage evolution, and in terms of local response, such as shear distortion of the joint panel and measured strain of strengthening steel strips. The effectiveness of the tested strengthening solutions is evaluated through a comparison with the response of the reference (as-built unreinforced and reinforced with code-compliant joint stirrups) specimens.

Out-of-plane (OOP) collapse of masonry infill panels in existing reinforced concrete (RC) buildings due to seismic events is a key issue for life safety and seismic economic loss estimation. Few studies in the literature deal with this topic and, above all, with possible strengthening strategies against the OOP collapse. This work presents the main results of an experimental campaign about different strengthening solutions to mitigate the OOP collapse of masonry infills in RC buildings. The investigated strengthening techniques were based on the application of a thin mortar plaster and fiber-reinforced polymer nets with different connection typologies with the surrounding RC frame. The specimens were realized with traditional horizontal hollow clay bricks and were tested through the application of a semi-cyclic OOP displacement pattern by means of uniformly distributed small pneumatic jacks. Tests data and results are presented and commented in terms of OOP force-displacement responses and damage evolution. Details about the effectiveness of each retrofitting solution are provided and compared to support the selection of the best strategy for future applications.

The estimation of direct and indirect losses due to earthquakes is a key issue in the Performance Based Earthquake Engineering framework. The analysis of damage data in literature highlights the key role played by damage to nonstructural components on the resulting losses, namely, infills and partitions, in Reinforced Concrete (RC) Moment Resisting Frames (MRF). Therefore, the use of simplified methods leading to the definition of repair costs, fatalities, and repair time due to earthquake, reproducing the influence of infills on the global behaviour of RC frames, is very attractive for insurance and risk management strategies. In commonly adopted loss computation tools, no specific data related to masonry infill panels, widespread in moment-resisting-frame residential buildings, are available to perform a probabilistic assessment of losses. To fill this gap, specific fragility and loss functions have been recently proposed in the literature. To assess their validity and estimate the relevance of the repair costs due to infills after earthquakes with respect to the total reconstruction process, the present work analyses a subset of Reinforced Concrete residential buildings with masonry infills struck by the 2009 L’Aquila (Italy) earthquake, focusing on “lightly” damaged buildings, where only damage to masonry infills occurred. In such a way, the evaluation of repair costs can be made by neglecting the contribution due to repair activity to other structural components (namely vertical structures, horizontal structures, stairs, roofs). Based on available data related to these buildings, the observed damage scenario after L’Aquila earthquake is first obtained. Then, a simplified mechanical method – PushOver on Shear Type models (POST) – for seismic vulnerability assessment of infilled RC buildings is used to obtain a predicted damage scenario to be compared with the observed one. The repair costs for infills are estimated given the observed and the predicted damage scenarios, by means of the cost functions at given damage states (DSs) reported in the most recent literature for infill panels. Additionally, the resulting estimated repair costs are compared with the actual repair costs presented in the available literature for the investigated subset of buildings, and the percentage influence of infills on the total repair costs due to earthquakes for residential buildings is lastly computed.

The presence of masonry infills in Reinforced Concrete (RC) frames leads to the increase in their lateral strength and stiffness. Nevertheless, post-earthquake observed damage showed that infills can also cause potential brittle failures due to the local interaction with structural elements, thus producing a limitation of deformation capacity of the surrounding frame. A proper numerical model both for infills and RC members is necessary to reliably detect the shear failure of columns due to the local interaction with the masonry infill. Several researches dealt with this topic, by using the equivalent strut model or more complex models like the double- and triple-strut models or FEMapproaches. Nevertheless, the choice of the proper modelling strategies and degrading shear strength model is still a frontier issue for the most recent research works. This paper presents a preliminary numerical investigation on column shear failure due to the local interaction with masonry infills, starting from the results of some experimental tests on infilled frames presented in the literature, which exhibited this kind of failure. Different shear strength models and different strategies of macro-modeling for infills are applied to numerically reproduce the column shear failure and the global response. The modeling strategies are lastly compared with the experimental results to provide a support towards the choice of the most reliable numerical approach.

Experimental tests on four full-scale exterior unreinforced reinforced concrete (RC) beam-column joints, representative of the existing non-conforming RC frame buildings, are carried out. The specimens have different longitudinal reinforcements (plain or deformed) and they are designed in order to be representative of two typical design practices (for gravity loads only or according to an obsolete seismic code). Different failure modes are observed, namely joint failure with or without beam yielding. The local response of the joint panel is analyzed. The different joint deformation mechanisms and their contribution to the deformability and to the energy dissipation capacity of the sub-assemblages are evaluated.

Lysosomal storage disorders (LSDs) are inherited diseases characterized by lysosomal dysfunction and often showing a neurodegenerative course. There is no cure to treat the central nervous system in LSDs. Moreover, the mechanisms driving neuronal degeneration in these pathological conditions remain largely unknown. By studying mouse models of LSDs, we found that neurodegeneration develops progressively with profound alterations in presynaptic structure and function. In these models, impaired lysosomal activity causes massive perikaryal accumulation of insoluble α‐synuclein and increased proteasomal degradation of cysteine string protein α (CSPα). As a result, the availability of both α‐synuclein and CSPα at nerve terminals strongly decreases, thus inhibiting soluble NSF attachment receptor (SNARE) complex assembly and synaptic vesicle recycling. Aberrant presynaptic SNARE phenotype is recapitulated in mice with genetic ablation of one allele of both CSPα and α‐synuclein. The overexpression of CSPα in the brain of a mouse model of mucopolysaccharidosis type IIIA, a severe form of LSD, efficiently re‐established SNARE complex assembly, thereby ameliorating presynaptic function, attenuating neurodegenerative signs, and prolonging survival. Our data show that neurodegenerative processes associated with lysosomal dysfunction may be presynaptically initiated by a concomitant reduction in α‐synuclein and CSPα levels at nerve terminals. They also demonstrate that neurodegeneration in LSDs can be slowed down by re‐establishing presynaptic functions, thus identifying synapse maintenance as a novel potentially druggable target for brain treatment in LSDs.

The influence of masonry infills on the seismic behaviour of reinforced concrete buildings has been widely studied in terms of their strength and stiffness contribution in the in-plane direction while less studies have been carried out on their response in their out-of-plane (OOP) direction. OOP collapses were observed on recent earthquakes motivating experimental efforts to characterize this behaviour combined and not with previous damage due to in plane loading demands. The present paper pretends to compare the test findings of two different experimental campaigns carried out on full-scale and scaled infill masonry panels under out-of-plane load. The main results of both experimental campaigns will be detailed and discussed to evaluate the key parameters that governed the infill panels OOP behaviour. The results will be presented in terms of force-displacement envelopes, energy dissipation and failure modes. Besides that, the second main goal of the manuscript is to present the comparison of the experimental results with the analytical models available in the literature.

Earthquakes occurred in the last twenty years in Mediterranean area had a significant impact at economic and social level. A significant part of economic losses for RC frames was due to damage to non-structural components, particularly to masonry infills and partitions. Therefore, the seismic behaviour of masonry infills should be reliably characterized through a correct definition of their displacement capacity at different damage states (DSs), and of the required repair activities after an earthquake with their relative costs, to improve the seismic damage assessment and loss evaluation for infilled RC frames. Therefore, the main goals of this study for a more reliable loss estimation are: (i) the analysis of the displacement capacity at given DSs aiming at the definition of drift-based fragility functions; and (ii) the analysis of direct losses due to damage to infills after seismic events. First, an extensive database of experimental tests on RC frames infilled with clay bricks or concrete blocks is collected. By means of the collected experimental results, drift-based fragility curves are defined, explicitly depending on infill brick materials. The influence of openings on displacement capacities is also evaluated. Finally, seismic losses related to infills are computed, providing expected monetary loss, also in this case depending on the infill typology. All the required repairing activities are listed and their cost are computed. Loss functions directly depending on IDR demand are finally provided for all the investigated infill typologies, thus fusing together damage and loss analysis for a simpler practice-oriented loss calculation.

Reinforced Concrete (RC) buildings with clay masonry infills are a very common structural typology worldwide for civil, strategic or productive use. Damage to infills may cause danger for human lives and strongly affects economic losses, as shown during past earthquakes. Despite their role is crucial in terms of global and local response of RC buildings in the event of an earthquake, in current practice, infills are considered as partition elements without any structural function. The behaviour of infills under seismic actions has to be reliably characterized, starting from the analysis of their displacement capacity at different performance levels due to in-plane actions, and a proper complete numerical modelling, able to reproduce their influence on the global behaviour of RC frames under seismic actions. Some models have been already proposed in literature, but their reliability should be yet proved on the basis of an as wide as possible experimental database. Therefore, in this paper, a homogenous extensive database of experimental tests on RC frames infilled with hollow clay-masonry infills – typical of Italian and Mediterranean RC building stock – is collected and presented. The experimental responses of the infills under lateral loads are obtained and the main related numerical models existing in literature are investigated and compared with the experimental results. A new modelling proposal is carried out to obtain a simple practice-oriented force-displacement envelope to significantly reduce the errors in the prediction of the infill in-plane behaviour under lateral loads. The experimental evolutions of damage under increasing displacement demand are also analysed, and the displacement capacity at given performance levels are identified and correlated to the in-plane behaviour of the infill panels. The analysis of the damage evolution to the infills during the experimental tests finally allows the definition of drift-based fragility functions for these components, representing a key point for a more reliable estimation of losses due to earthquakes.

Reinforced Concrete (RC) framed buildings with clay masonry infills represent a very common structural typology worldwide for civil, strategic or productive use. Nevertheless damage to infills may cause danger for human lives and strongly affected economic losses due to past earthquakes, in current practice, infills are considered as partition elements without any structural function. However, their role is crucial in terms of global and local response of RC buildings in the event of earthquake. Their behaviour under seismic actions should be reliably characterized, starting from the analysis of their displacement capacity at different performance levels due to in-plane actions, and a proper numerical modelling, able to reproduce the influence of infills on the global behavior of RC frames under seismic actions. Some models have been already proposed in literature, but their reliability should be yet proved on the basis of an as huge as possible experimental database. In this paper, a homogenous extensive database of experimental tests on RC frames infilled with hollow claymasonry infills – typical of Mediterranean RC building stock – is collected and presented. The experimental responses of masonry infills under lateral loads are obtained. The main numerical models existing in literature for infills are investigated and compared with the experimental results in order to select the model that minimize the prediction error or to propose a new simplified model for the envelope of the infill response. The evolutions of damage under increasing displacement demand are also analyzed, and the displacement capacity at given performance levels are identified and correlated to the in-plane response of the infill panels. The analysis of the damage evolution to the infills during the experimental tests finally allows the definition of drift-based fragility functions for these non-structural components, representing a key point for a reliable estimation of losses due to earthquakes.

Reinforced Concrete (RC) framed buildings with clay masonry infills represent a very common structural typology worldwide. Infills are commonly considered as partition elements without any structural function nevertheless their role is crucial in terms of global and local response of RC buildings in the event of earthquake, and, therefore, their behaviour under seismic actions should be reliably characterized. One of the first issues to face with is related to a proper numerical modelling to reproduce the influence of infills on the global behaviour of RC frames under seismic actions. Some models have been already proposed in literature, but their reliability should be yet proved on the basis of an as huge as possible experimental database. Therefore, in this paper, a homogenous extensive database of experimental tests on RC frames infilled with hollow clay-masonry infills – typical of Italian RC building stock – is collected and presented. The experimental response of masonry infills under lateral loads is obtained. The main numerical models existing in literature for infills are investigated and compared with the experimental results in order to select the model that minimize the prediction error or propose a modification of the existing models.

This paper reports on the results of an ongoing Research Project aimed at computing the risk of collapse in code-conforming new Italian buildings. A companion paper describe the overall Research Project ([11]), funded by the Italian Civil Protection Department (DPC), its different areas of application (reinforced concrete, masonry, steel buildings, etc), the overall seismic risk calculation procedure and the ground motion selection process for the recorded ground motions used for the multi-stripe analyses. This paper deals with different classes of reinforced concrete buildings (namely 3-, 6- and 9- story high moment resisting frame) designed in cities with increasing seismic hazard. For the sake of brevity, only the results of 6-story buildings are reported. First, the paper describes the geometry, material characteristics and main design properties of the buildings, including their elastic dynamic properties. Three different configurations are considered: Bare Frame (BF), Infill Frame (IF) and Pilotis Frame (PF, that is a building with infills at all levels except for the ground level). Design of the first two configurations is identical, while the PF requires an increase in the design forces at the ground level. Second, the paper introduces the nonlinear models used for the nonlinear analyses: lumped plasticity models for beams and columns, strut and tie models for the infills. Since the buildings are designed according to capacity design principles, the nonlinear behaviors of beams and columns in shear and of beam-column joints are not considered. Pushover analyses are used to estimate the EDP (top floor displacement) value used for the definition of the collapse limit state. Finally, the results of the multi-stripe analyses are presented for ten different ground motion intensities.

Reinforced Concrete (RC) framed buildings with clay masonry infills are a very common structural typology worldwide for civil, strategic or productive use. Nevertheless damage to infills may cause danger for human lives and strongly affected economic losses due to past earthquakes, in current practice, infills are considered as partition elements without any structural function. However, their role is crucial in terms of global and local response of RC buildings in the event of earthquake, and, therefore, their behaviour under seismic actions should be reliably characterized, starting from the analysis of their displacement capacity at different performance levels due to in-plane actions. In this paper, a homogenous extensive database of experimental tests on clay-masonry infilled RC frames is collected and presented. Displacement capacity at given performance levels are identified and correlated to the in-plane behaviour of the infill panels. The analysis of the damage evolution to the infills during the experimental tests finally allows the definition of fragility functions for these non-structural components, representing a key point for a reliable estimation of losses due to earthquakes.

Reinforced concrete buildings designed according to obsolete seismic codes or for gravity loads only are widespread in Italian and Mediterranean building stock. Past earthquakes showed that, for these buildings, shear failure in beam–column joints can lead to structural collapse mainly due to the inadequate joint confinement. The construction details used in these structural elements are commonly recognized as the likely cause of non-ductile structural failure modes under seismic actions, due to the lack of capacity design principles. A significant amount of research on seismic performance of unreinforced beam–column joints has been carried out in last years, but a very few portion of them handled with specimens unreinforced in the joint region and with plain hook-ended longitudinal bars. A higher number of tests is needed to deeper understand joint seismic response in order to validate the (few) existing models or calibrate new ones. This study aims at improving the understanding of seismic performance of exterior non-conforming joints in existing RC buildings. Two experimental tests on joints without transverse reinforcement are designed and carried out. The specimens are different for beam longitudinal reinforcement ratio and they are both reinforced with plain longitudinal bars. Two different kinds of joint failure are expected, with or without yielding of the adjacent beam. Design criteria, adopted setup and main experimental results are described. Strain gauges located on beam bars and displacement transducers on the joint panel allow the complete definition of both the deformability contributions of fixed-end-rotation and shear strain of joint panel. Finally, a comparison between joint shear strength models existing in literature or codes and experimental results (considering a wider experimental database) is carried out.

In the assessment of the performance of typical existing buildings, seismic collapse safety might be significantly affected by the non-linear behaviour of the joints that are involved in the failure mechanisms, especially if they are characterized by poor structural detaili ng, such as the lack of an adequate transverse reinforcement in the joint panel. Many retrofit strategies for ex isting joints are available, but commonly accepted tools to assess existing joint capac ity – which is the starting point for retrofit – are not available. Few reliable approaches for modelling all sources of nonlinearity are proposed in literature for poorly designed beam-column joints because of relatively poor informa tion from experimental tests. The current study aims to improve the understanding of exterior joint seismic performance without transverse reinforcement in existing RC buildings through experimental tests. Two full-scale exterior unreinfor ced beam-column joint sub-assemblages are tested under cyclic loading. Two different kinds of joint failure are expected, with or without the yielding of the adjacent beam, basically depending on the beam longitudinal reinforcement ratio. Stra in gauges located on beam bars and LVDTs on the joint panel allow the complete definition of the deformability contributions. Design criteria, adopted setup and main experimental results are described.

Over the last few decades, metropolitan areas have experienced a dramatic increase of exposure to earthquakes. Because of the still very low probability level at which short‐term earthquake forecasting is feasible, earthquake early warning systems (EEWS) currently represent an effective, pragmatic, and viable means for the implementation of protective measures to reduce the exposure of population to seismic risk. EEWS can be simply defined as systems that integrate seismic networks and software capable of performing real‐time data telemetry and analysis to provide alert messages to users within seconds of the beginning of an earthquake and certainly before that the S waves generated by the event reach the users. Worldwide, a number of EEWS capable of rapidly performing seismological analysis of ground motion during a strong earthquake are currently operative or are under real‐time testing (e.g., in Japan, Taiwan, Mexico, Italy, Turkey, California, etc.; Allen and Kanamori, 2003; Kanamori, 2005; Allen et al. , 2009). A tangible example of EEWS benefit is given by the experience of the OKI factory in the Miyagi prefecture in Japan that, after having experienced severe damages in 2003 due to two earthquakes, installed an EEWS, and at the following earthquakes experienced a significant reduction of losses (Allen et al. , 2009). Moreover, the Japan Meteorological Agency has shown the effectiveness of a combined on‐site and network‐based approach to rapidly broadcast the rapid warning after a potential damaging earthquake (Hoshiba, 2013). The key parameter of EEWS is the lead time, which is the time available for taking protective measures at distant targets once an earthquake has been promptly detected and …

The main features of the Reinforced Concrete (RC) building stock that was struck by the Emilia 2012 earthquake and damage observed after the event are analyzed. Building stock characteristics and historical seismic classification are employed for the definition of two benchmark structures, representative of the whole building stock. Seismic capacity of the two structures, at different damage states, is assessed through static push-over analyses, within the N2 spectral assessment framework. Infill panels׳ contribution in terms of strength and stiffness is explicitly taken into account in the analytical model. Damage States are defined according to a mechanical interpretation of EMS-98 scale. Fragility functions at each Damage State are obtained through the application of a Response Surface Method. Finally large-scale damage scenarios are obtained crossing the geo-referenced census data regarding the characteristics of the Emilia RC building stock and starting from the seismic input provided by the shake map of the event. The scenarios seem to be in reasonable agreement with the observed damage.

During last decades, post-earthquake damage (e.g., L'Aquila 2009, Lorca 2011) numerical and experimental studies showed that a growing attention should be addressed to the influence of infills on the seismic performance of Reinforced Concrete (RC) buildings. In this paper, a numerical investigation on the influence of infills on the seismic behavior of RC structures is carried out. Four different case study buildings are analyzed: four- and eightstorey buildings, designed for seismic loads and for gravity loads only. Seismic capacity at two Limit States (Damage Limitation and Near Collapse) is assessed through static push-over analyses, within the N2 spectral assessment framework, and different infill configurations are considered (Bare, Uniformly Infilled, Pilotis). A comparison between IN2 curves related to the different structures is carried out, in order to evaluate seismic response, depending on the number of storeys, the design typology and the infill configuration. Then, fragility curves at both Limit States are obtained, through the application of a Response Surface Method. Seismic performance is also expressed in terms of failure probability, given a reference time period. Moreover, a comparison between fragility analysis results and observed damage during L’Aquila earthquake is carried out, in particular at Damage Limitation Limit State.

The present study reports results of pseudo-static experimental tests on one-storey one-bay Reinforced Concrete (RC) frames with and without masonry infill walls. Four specimens were tested, two designed for Gravity Loads only according to Italian technical code provisions in force during 1970s-90 s (GLD), and two designed for Seismic Loads according to current code provisions (SLD). Specimens were built in 1:2 scale and tested with and without infill walls, made up of 80 mm thick hollow clay units typical of light non-structural masonry. Test setup was designed in order to reproduce the behaviour of the frames under seismic action, thus avoiding any direct interaction between setup elements used for imposing lateral displacement and beam-column joints. SLD frames, which were designed according to capacity design principles (i.e. strength hierarchy rule between elements and failure modes), showed a ductile behaviour, as expected. The presence of the infill wall led to a stiffness and strength increase in the global response of the frame, without affecting the response of RC elements. Brittle failure mechanisms played a key role in the response of GLD frames, due to local interaction between infill wall and RC elements and to beam-column joint behaviour, in specimen with and without infill wall respectively.

A growing attention has been addressed to the influence of infills on the seismic behavior of Reinforced Concrete buildings, also supported by numerical and experimental analyses, and by the observation of damage to infilled RC buildings after recent earthquakes (e.g. L'Aquila 2009, Lorca 2011, Emilia 2012). In this paper, the attention is focused on the Damage Limitation Limit State (DL LS), defined as dependent on displacement capacity limit directly related to the damage to infill panels. Although inelastic (post-cracking) displace- ment demand in RC members at this LS can be quite low, infill behavior can be already strongly non linear, if a diffuse state of cracking has begun to arise in infill panels. Thus, based on the results of several non linear dynamic analyses, a reduction factor of the initial elastic stiffness of infills is estimated, in order to obtain an effective stiffness of infill panels to be used in a linear analysis in order to obtain a displacement demand at DL LS (i.e., maxi- mum Interstorey Drift Ratio) which is approximately equal to the demand evaluated through non linear dynamic analysis on the same model. To this end, Incremental Dynamic Analyses (IDAs) are performed on four- and eight-storey infilled frames, designed for seismic loads according to the current Italian technical code and for gravity loads only according to an ob- solete technical code. Influence of number of storeys and design typology on the obtained ef- fective stiffness is also analyzed.