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Despite significant progress in research and development of aluminum shear panels in recent decades, their implementation for seismic retrofit of existing reinforced concrete (RC) buildings can still be significantly extended. Their application is limited by the general lack of relatively simple and effective design criteria and proper guidelines. This paper develops a design method for the seismic retrofit of reinforced concrete buildings using aluminum multi-stiffened shear panels as dampers. Both the nonlinearity in the structure and the dampers-structure interaction are considered to give an optimal distribution of the shear panels over the height of the building. The analytical laws refer to dissipative aluminum shear panels recently tested and analyzed by the authors. The proposed procedure has been described in detail. Its applicability has been demonstrated by analyzing two typical RC buildings having drift capacity-to-demand ratios ranging from 0.505 to 0.624. The design value of the panel-to-frame stiffness ratio has been found to range from 0.594 to 1.432 as a function of the lateral stiffness of the existing building. The verification of the proposed procedure has been carried out by checking the validity of the design assumptions. The first one (i.e., the mode shapes remain the same before and after retrofit) has been checked using the modal assurance criterion that gives values ranging from 0.992 to 0.998. The second one (i.e., uniform yield drift distribution over the building height) has been checked by comparing the yield drifts with their average value giving a standard deviation ranging from about 11 to 15%. The effectiveness of the design method has been finally validated through nonlinear time-history analysis for different seismic accelerograms and hysteresis models. The results show that the seismic retrofit design procedure is effective in significantly reducing inter-story drift (maximum inter-story drift ratio demands ranging from 1.04 to 2.07%) thus satisfying the acceptance criteria of the building, and avoiding drift concentration and consequential weak story collapse.

Seismic retrofit of an existing steel-reinforced concrete hospital building that features innovative use of a continuous energy-dissipative steel column (CEDC) system is presented in this paper. The special system has been adopted to provide an efficient solution taking into account the difficulties of applying traditional intervention techniques to minimize the impact on architectural functionality and avoid the loss of building function and evacuation during the retrofit implementation. The lateral stiffness and strength of the CEDC system were defined based on the geometric and mechanical properties of the steel strip dampers. The hysteretic behavior under cyclic loadings was defined using a simplified numerical model. Its effectiveness was validated by comparing the results of full-scale experimental data available from the literature. All the main design considerations of the retrofitting plan are described in detail. The effectiveness of the proposed retrofitting system was demonstrated by nonlinear time-history analyses under different sets of earthquake-strong ground motions. The analysis results show that the CEDC system is effective in controlling the deformation pattern and significantly reducing damage to the existing structure during major earthquakes.

The present study deals with numerical modelling of multi-span masonry arch bridges under seismic loading. Based on the evidence coming from an experimental program reported in the literature, a reference 3D nonlinear Finite Element model is calibrated. The numerical model is realized in Abaqus software by adopting a macro-modelling strategy for simulating the masonry behavior. To this purpose the Concrete Damage Plasticity material model is used. The backfill material follows a Drucker-Prager behavior, while the interaction between the two materials is simulated by means of an appropriate contact constitutive law. After calibration, the response of the bridge under longitudinal seismic loads is thus investigated. In particular, a mass proportional load distribution is adopted. Then, the effects of the mechanical parameters of the backfill material on the global response of the bridge are investigated by means of a parametric analysis, which is carried out by varying: i. elastic modulus, ii. cohesion, iii. backfill-masonry contact law, and iv. backfill friction angle. The obtained results provide preliminary indications about reliable retrofitting techniques for cases similar to the one under consideration.

In this paper, an experimental investigation addressed at the characterization of compressive strength of a weak units-strong mortar masonry is presented. This masonry, made with natural units of calcarenite improperly named “tufo”, is massively recurrent in the historic center of Matera, an UNESCO site since 1993. The tufo masonry was used for building ordinary and historical constructions, such as ancient churches and palaces, and nowadays it is extensively applied for restoration interventions in order to preserve the historic site and its surrounding area. At first, the research focuses on the evaluation of compressive strength of masonry components, by examining tufo cubic units and lime mortar prisms, and to propose relationships between non-destructive (sonic) and destructive (compression) tests statistically validated. Then, some formulations for estimating the masonry compressive strength by combining those of the basic masonry components are examined. Comparisons with results obtained with prism specimens (doublets and triplets) confirm that in this type of masonry compressive behavior (failure mode and compressive strength) is strictly dependent on tufo units. Finally, a probabilistic study of strength distribution highlights the importance of taking into account the compressive strength dispersion of each component, especially the one related to tufo units.

Introduction: A large portion of the Italian built heritage is characterized by a significant seismic vulnerability since many structures were designed with outdated criteria, i.e., without accounting for seismic actions. This aspect is particularly relevant for strategic structures and infrastructures, whose functionalities are crucial in case of seismic events. Objective: The main aim of the present paper is to share the key findings related to the seismic vulnerability assessment of the National Institute for the Study and Treatment of Cancer (IRCCS) “Giovanni Pascale Foundation” in Naples. In particular, the main evidences could be easily extended to existing hospitals realized in the last century, with the main reference to: construction techniques, quality of constructional material, overt and convert seismic vulnerabilities and possible intervention strategies for risk mitigation. Methods: In the present paper, the assessment methodologies adopted for such a strategic hospital complex are provided, focusing in particular on: i. preliminary research of original design documents and on-site investigation for determining constructional details; ii. material tests on structural elements; iii. vulnerability seismic assessment by means of non-linear FE analyses (push-over and capacity spectrum method); iv. recommendations on retrofitting measures and cost estimations. Results: The conducted study puts into clear evidence the inadequacy of the investigated buildings to face the design seismic actions provided by the current Italian code and thus showed the significant seismic vulnerabilities affecting the Institute “G. Pascale Foundation” of Naples. Among these, particular attention has also been focused on the so-called intrinsic vulnerabilities, namely the ones not measurable explicitly and interesting non-structural elements (e.g., connection of shelves, stained glass windows, facilities, etc.). Conclusion: The presented case study highlights the strong seismic vulnerability affecting structures realized in the past century, despite their strategic functions. On the whole, the examined structures can be considered as representative of this building typology, and the adopted calculation criteria, as well as the assumptions of the assessment process, could be easily extended to similar case studies.

Curved structures (i.e. arches and vaults) are recognized as distinctive elements of the masonry built heritage, and in particular of churches. If on the one hand they represent structural and architectural elements of signifi-cant values, on the other they can experience important damage in case of seismic actions, being characterized by significant vulnerability. The structural assessment of masonry curved structures can be based on several simplified geometrical representations and performed at different detail levels, including limit analysis (with a kinematic or static approach) and finite or discrete element modelling. Therefore, the present paper focuses on the seismic response of curved structures in historical masonry, investigated by means of different approaches. In particular, a comparative assessment of these approaches is carried out considering multiple configurations including i. stand-alone arches; ii. arches supported by lateral piers; iii. triumphal arches (diaphragm arches). Strengths and limits of each method are compared, highlighting possible differences in the collapse predic-tions. Also, by means of parametric analyses, the main sources of vulnerability and failure modes of curved structures are investigated and critically assessed.

The present paper focuses on traffic load definition for road bridge design according to past Italian codes. In particular, starting from the first code of ’33 up to the current Technical Standard for Constructions (NTC2018), several different approaches have been assumed by the codes. Hence, a historical review is firstly proposed and each code is analyzed together with the proposed load schemes. Such a review has allowed the definition of a parametric investigation on typical Italian r.c. decks. In particular, bending moments due to the traffic loads for which the bridges were conceived are investigated, and thus a preliminary estimation of past-to-current design bending moment ratios is carried out with reference to continuous beams.

Seismic performance and dynamic characteristics of bridge structures are highly influenced by their geometric properties. This paper aims at studying the impact of substructure irregularity on the seismic vulnerability of multicolumn-bent short-span bridges by estimating the capacity of bridge components. For this purpose, incremental dynamic analyses have been performed on two five-span bridge configurations, chosen according to a real case study. The studied bridges present supported on seat-type abutments and differ according to pier heights: regular and irregular substructures with equal and different heights, respectively, have been considered. Pounding of the bridge superstructure portion and nonlinear backfill soil behavior are accounted for in nonlinear time history analyses. Spectral acceleration of the first fundamental period and peak ground velocity are considered as intensity measures, while failure criteria consisted on maximum columns drift ratio and deck unseating at abutments. The performed analyses revealed a response of the irregular bridge significantly worser than the regular one. Besides, the two failure criteria affect the seismic vulnerability of the regular bridge almost equally and for the irregular bridge, column damage is always recognized to be the main reason of the structural collapse.

In the scientific community there is an increasing attention to existing bridges. They usually suffer a marked structural deterioration due to a lack of maintenance although they belong to infrastructures serving an important amount of traffic. Therefore, there is the need of quickly evaluating the current state of these structures with the aim of promptly expressing a judgment about their usability. In this paper, the results of a fast appraisal method applied to a territorial case study are illustrated and commented in order to define a list of priority and the related additional investigations, including in situ tests and numerical analyses with more refined models. The paper concludes highlighting the importance of applying this decision tool in order to manage huge and important road infrastructures in conjunction with the interested traffic, and to plan more refined investigations within a multi-level evaluation framework.

In fase di modellazione risulta fondamentale effettuare un’adeguata previsione delle prestazioni di giunti metallici, per evitare possibili errori nella valutazione della resistenza e della deformabilità delle strutture cui appartengono. Ciononostante, la progettazione dei giunti predilige ancora modelli semplificati, quali il “modello cerniera” per i telai pendolari e il “modello incastro” per i telai a nodi rigidi, ignorando la possibilità di avere giunti semi-rigidi e telai semi-continui. Il presente lavoro ha lo scopo di valutare l’influenza di giunti semi-rigidi e a parziale ripristino di resistenza sulle prestazioni sismiche di edifici in acciaio monopiano in cui i nodi trave-colonna e colonna-fondazione sono stati progettati come continui. A tal uopo, è considerato un campione di edifici esistenti. Viene applicato dapprima il Metodo delle Componenti per stabilire se i giunti, nella realtà, hanno le caratteristiche di rigidezza e resistenza attese. Ciascuna struttura è poi riprodotta attraverso modelli ad elementi finiti, sui quali sono condotte analisi lineari e non lineari per confrontare l’influenza di differenti tipologie di vincolo sul comportamento globale. Tale confronto è implementato in termini di curve di fragilità, finalizzate anche a stabilire l’eventuale necessità di interventi di rinforzo dei giunti.

The protection and conservation of historical monumental assets is a priority for contemporary societies. As it is widely recognized, historical masonry buildings (and in particular masonry churches) are unable to adequately withstand horizontal actions and generally suffer heavy damage if struck by a seismic event. Although a correct evaluation of their seismic capacity is necessary in order to preventively plan retrofitting interventions, the complexity of the constructions and the uncertainties in material modelling make it difficult to fully understand the behaviour of masonry churches. In this context, the macro-element approach is largely applied and confirmed by the partial collapses observed after the last seismic events. In this paper, a simplified procedure based on the limit analysis is introduced to evaluate the seismic capacity of triumphal arches, considered as part of the most vulnerable macro-elements in masonry churches. Triumphal arches from churches affected by the L’Aquila (2009) and Central-Italy (2016–17) earthquakes have been investigated by means of a linear kinematic approach, defining the possible positions of the non-dissipative hinges through step-by-step numerical analyses. The obtained results, finally, have been compared with the damage scenario observed in the considered triumphal arches, aimed at evaluating the effectiveness of the proposed procedure.

Masonry bell towers often represent a distinctive element of the Italian landscape. Their different typological, constructive, and structural peculiarities, along with the great exposure given by their relevant artistic value, make them both structurally and seismically vulnerable. Since the conservation of masonry bell towers requires a multidisciplinary approach, the PREVENT project (Integrated PRocedure for assEssing and improVing the resiliENce of existing masonry bell Towers on a territorial scale) aims at defining a two-level procedure for assessment and enhancement, at both a territorial and architectural scale. In this paper, the preliminary results that emerged from the first census carried out on a surveyed population of 56 masonry bell towers in the city of Naples (Italy), are presented. A classification has been made from a geometric-typological point of view, in order to frame their structural peculiarities. Also, preliminary assessments of the dynamic behaviour of a sub-sample of 40 masonry tower bell towers (i.e. excluding the bell-gables and double tower types) have been carried out. Further analyses will allow the elaboration of “resilience” indexes, as synthetic indicators of the architectural, historic, and cultural value, as well as of the structural safety, of the considered bell towers.

The paper deals with the preservation of Italian bridge assets, which may suffer structural deficiencies mainly due to the state of conservation, as well as to outdated adopted design criteria. A systematic procedure aimed at assessing the structural risk affecting existing bridges has been recently introduced by the “Italian Guidelines for classifying, managing the risk, assessing the structural safety and monitoring existing bridges”. The procedure at issue entails the assessment of hazard, vulnerability and exposure based on typological data, which are combined in order to obtain an attention class in order to define the future measures to be adopted. In this paper, the application of such a procedure on a sample of 75 bridges of Caserta, Italy, is presented and the main results are shown. In the whole, the study confirms the necessity to adopt far-sighting and smart policies by handling bodies. On the other hand, some critical aspects in relation to possible missing data in existing censuses are addressed and possible solutions and alternative methods are discussed.

In the present paper the structural efficiency of high-rise steel buildings is investigated. Five different structural typologies widely adopted in the European and many other world areas are considered, namely: Moment Resisting Frame [MRF], Concentrically Braced Frame [CBF], Braced Tube [BT], Diagrid Structure [DGR] and Outrigger Structure [OTR]. The structural efficiency is evaluated in terms of total structural weight with respect to slenderness (i.e. height-to-base dimension) ratio. For each typology, the height of a building with a squared plan (21 m x 21 m) is increased and the dimension of steel elements necessary for attaining a predefined level of structural safety are evaluated. Common assumptions are considered with reference to section types of structural elements and external actions. Then, FEM models are employed, and the dimensions of structural steel elements are varied for each structural typology and height to satisfy structural checks. At this purpose, a trial-and-error procedure is followed to optimize the structural configuration. The analyses allowed for defining qualitative "efficiency curves", relating, for each structural typology, the amount of steel weight necessary to ensure the minimum required structural safety.

The present paper deals with new management policies adopted for the smart handling of the statal road bridge asset in the Campania region, Italy. The research group of the University of Campania “Luigi Vanvitelli”, as member of the FABRE consortium, provided a scientific support to the handling body for applying to a number of current bridges the multi-level approach proposed in the recently enacted Italian “Guidelines for classifying and managing the risk, assessing the safety and monitoring existing bridges”. In the present study, the main outcomes obtained in the first phase of this activity are presented with reference to about 20 bridges. Hence, a characterization of the entire sample of interest (80 bridges) is firstly proposed and then the preliminary outcome obtained during the visual surveys are presented and discussed. The main causes of deterioration and damage phenomena, as well as the general conservation state of existing bridges, can be identified based on the presented results.

Masonry buildings constitute a significant portion of the architectural heritage all over the world, also in regions affected by a high seismic hazard. Since this constructional material is character-ized by lack of tensile strength, as well as small deformation capacity, masonry structures could result hugely damaged if shaken by seismic forces. In order to avoid collapses and reduce struc-tural damage, innovative retrofitting interventions are necessary to improve the seismic behavior of masonry structures. In this context, steel-based techniques could be considered among the most suitable solutions. In fact, by using such a high-performant material, additional strength and ductility may be conferred to existing masonry structures. Based on these premises, the present paper focuses on a numerical investigation of two different retrofitting techniques: the CAM© sys-tem and the application of steel grids on both faces of a masonry wall. In particular, on the base of an experimental test carried out within the research project In.CAM.M.I.N.O. on an unreinforced masonry wall tested in condition of constant vertical force and horizontal loads, a reference FE Model has been calibrated in Abaqus by using a macro-modelling approach with a damage-plas-ticity material model for the masonry. Then, based on the reference model, the efficiency of the two systems has been investigated and compared by means of numerical analyses, in order to eval-uate the strength and ductility increases obtainable by the application of the two retrofitting tech-niques.

The paper focuses on masonry arch bridges, which represent a significant portion of the entire infrastructural asset of both road and railway networks, despite their ancientness. The study is part of a wider activity that the Province of Caserta and the Department of Architecture and Industrial Design of the University of Campania “Luigi Vanvitelli” are jointly carrying on. Such a collaboration is aimed at defining and applying methodologies for a correct and smart handling of road bridges spread on the territory of the Caserta district, whose infrastructural heritage counts about 900 bridges. Within this activity, preliminary data concerning the typological characteristics of about 100 masonry arch bridges were collected. These data allowed to recognize typical features distinguishing masonry arch bridges of this area, which can be considered representative also at a national level. Then, evidence from some in-situ inspections performed on 50 bridges are also presented. In particular, the main structural issues have been surveyed and a statistical analysis of the observed defects has been carried out. The study highlighted the main structural issues typically affecting existing masonry arch bridges, as well as the need to adopt far-sighting managing policies for administrative bodies called to handle wide infrastructural heritages.

The study deals with an existing RC bridge in Province of Caserta, Italy, realized between ’50s and ’60s of the last century, the so-called Agnena bridge. The bridge, whose functionality is strategic for the local road network, in the recent past has been affected by relevant geological issues, which provoked a significant crack pattern in the deck elements and abutments. Nevertheless, the social and economic issues related to the closure of such a strategic infrastructure, has led the competent administration (Province of Caserta) to carry out additional assessments with the aim to guarantee, even in a reduced condition, its functionality pending the realization of a final intervention (i.e. demolition and reconstruction). At this aim, the recently enacted Italian Guidelines for existing bridges have been taken as reference for the traffic load definition. Hence, an analytical assessment has been carried out by adopting a numerical FE Model. Then, it has been verified that a limited transitibility could be permitted on the structure, thanks to a provisional intervention and a monitoring system. On the whole, the proposed interpretation of the main Italian legislative documents could be profitably adopted for similar cases needing a reduced operatively for limited periods.

The present manuscript deals with the seismic vulnerability assessment of existing masonry churches, which is a fundamental process for risk and consequent prioritization analyses, as well as application of effective retrofitting strategies. In the past, different approaches with various levels of accuracy and application ranges have been developed to assess the vulnerability to damage of such structures in case of seismic events. Based on the classification provided in the Italian Guidelines for the Cultural Heritage, in this paper a review of seismic vulnerability assessment methodologies for existing masonry churches is presented. The main goal of the current study is to provide a critical comparative overview about these procedures, highlighting the main issues related to the application of each detail level. Moreover, particular attention is focused on the applications present in literature, allowing for the definition of a potential systematic procedure for smart management policy aimed at preserving cultural, architectural and historical heritage.

The safeguard of historical heritage cannot disregard a rational assessment of the seismic vulnerability of the assets, especially in areas as Italy where high exposure and hazard may lead to significant risk. In this context, while established empirical methods based on observed damage after earthquakes are available for some constructional typologies as churches and palaces, large-scale approaches for masonry bell towers aimed at defining a vulnerability ranking for prioritisation of intervention are still missing or not sufficiently validated. In this paper, a novel simplified vulnerability model is formulated through sensitivity-informed parameter reduction of a more detailed mechanics-based assessment methodology. The framework is based on (a) a parametric representation of the bell tower, (b) a mechanical model providing a measure of collapse, (c) a vulnerability definition based on the measure of collapse. The variation ranges of the input parameters are calibrated against the results of the surveys carried out in the historical centre of Naples. A global sensitivity analysis is then used to identify the most important parameters governing the vulnerability of the structure and remove the least influential parameters. Vulnerability models based on different amount of input data are finally proposed, and their accuracy is assessed comparatively with the original mechanical model. The results show that good accuracy can be obtained by using six geometrical and typological parameters, while further increase in the quality of the prediction may be achieved with the introduction of additional information regarding materials and constructional features, which can only be acquired by means of more detailed surveys on-site.

Seismic events that struck Italy in the last years had a dramatic impact on historical and cultural heritage. Damage occurred on existing masonry buildings, in particular on churches, stressed out the need to better understand the seismic behaviour of this type of constructions as well as to define more appropriate mitigation strategies to be applied at large scale. This study deals with a predictive methodology for vulnerability assessment of churches in large territorial areas. Focusing the attention on three naves churches of Abruzzi, the paper proposes modifications and integrations of an existing methodology taken by literature. These modifications are defined through a calibration procedure based on damage observation of 64 three naves churches located at different distances from the epicentre of the 2009 earthquake. The proposed model is employed to predict damage level distribution for different earthquake intensities, allowing fragility curves to be plotted and therefore potential damage scenarios to be represented.

Masonry churches represent the major part of the Italian architectural heritage. Recent earthquakes stressed the high vulnerability of these constructions, provoking heavy structural damage and val...

The current research focuses on a numerical and analytical study aimed at investigating the efficiency of a steel-based reinforcement system suitable for existing masonry walls. The application of such a retrofitting technique, which consists of glued thin steel grids applied on both faces of a masonry panel, is reversible, cheap and easy to be executed and appears to be suitable especially for buildings with concrete slab or inter-stories beams to which the steel elements could be anchored. The study is based on a reference experimental test carried out at the “Politehnica” University of Timisoara (Romania), within the European FP6 project PROHITECH. The reference test provided the application of a constant ver-tical compression and cyclic horizontal displacements to an unreinforced brick-cement mortar wall in full-scale (1500 × 1500 × 250mm), to which was conferred a double-fixed constraint condition. Based on the experimental evidences, a reference numerical model has been implemented in ABAQUS, by adopting a plastic-damage material and a macro-element approach for the masonry modelling. Hence, in order to determine a design crite-rion of the studied system, a comparison with the analytical formulations available in the current Italian and European codes for the unreinforced configuration is presented in this study. Then, a wide parametric study on the investigated retrofitting technique has been carried out by varying thickness and spacing of steel grid elements, as well as the geo-metrical ratio of the panel (height/length). On the basis of the numerical results, a capac-ity formulation has been proposed, which takes into account the steel distribution in the masonry panel. The obtained outcomes revealed that the strength increase achievable by adopting the studied reinforcement system could be compared to the efficiency of a rein-forced masonry wall of new construction and it is strongly influenced by the geometrical ratio of the wall, as well as the steel distribution.

A novel typology of steel shear panel based on a web plate perforated according to Rectangular-Shaped Links (RSL) with internal links is proposed, to act as an energy dissipation element and improving the progressive overstrain behavior of typical shear plates. Preliminary experimental tests were carried out to investigate the behavior of the proposed system and to determine the influence of the main design parameters on the hysteretic response of tested specimens. The obtained outcomes evidenced that the shear strength, the stiffness and energy dissipation capacity of proposed shear panels are consistently influenced by overstrain in bending around the rectangular-shaped links, due to the slenderness of internal links. In particular, two different buckling modes were identified, namely global shear buckling of the plate, which is partially dissipative, and lateral-torsion buckling of individual rectangular-shaped links and internal links, which may result fully dissipative. Then, a FEM model has been implemented and validated according to the experimental results. Therefore, a parametric analysis has been carried out, considering the main parameters affecting the cyclic response of the specimen. The obtained outcomes allowed to conclude that the polar moment of inertia of links could be used together with the plate thickness to control the hysteretic performance of RSL specimens. In particular, the increasing of the width of internal links could allow the activation of global buckling of the plate, which generally causes significant pinching of hysteretic cycles. Based on the conducted parametric analyses, optimum web plate slenderness ratio and polar moment of inertia of links have been identified, providing useful suggestions for design of the proposed shear panel typology. In addition, an equation to predict the yielding shear strength of these kinds of shear panels has been suggested.

Introduction: The conservation and preservation of existing buildings, in particular public infrastructures, is currently a significant issue in Italy and Europe, considering their strategic role and the risk represented by human losses, management issues and also economic disruption in case of collapse. In this context, the interest in conservation is not restricted to monumental or artistical buildings but also includes the several buildings composing the Italian infrastructural heritage, which in many cases are made of reinforced concrete and show signs of ageing after half a century and more from their construction. Methods: On the basis of these premises, in the present paper, a preliminary investigation on an infrastructural case study located in Naples port is presented. Such a study is part of a research activity aimed at defining critical structural issues of the central administrative building of the Central Tyrrhenian Sea Port System Authority. Results: A system of high-sensitivity and low-cost MEMS acceleration sensors were installed on the structure, with the aim of investigating its dynamic behaviour. A Finite Element model of the building was created, including information about material properties and cross-section details from prior experimental activities. A model updating procedure was carried out, based on the dynamic data collected by the monitoring system and post-processed to estimate the fundamental frequencies. Conclusion: This has allowed highlighting the main features of the dynamic response of the building, and the critical role played by deformability of infill panels and floors on the modal properties of the structure.

Simulating the mechanical behavior of masonry structures with reasonable approximation using numerical models is a complex issue, mainly due to the uncertainties affecting the selection of mechanical parameters. Since destructive testing is in some cases impossible, the Italian building code provides ranges for the parameters based on masonry type to be used in numerical and analytical estimations of the capacity curves of masonry panels, suggesting the Equivalent Frame Method approach for the numerical modelling. In this paper, the application of these ranges to three more sophisticated material descriptions to be used in 3D representations (i.e. Double Drucker Prager, Total strain crack and Concrete damage plasticitymodels) is investigated, with reference to a heterogeneous set of experimental tests performed in the past. In particular, numerical, analytical and experimental results are compared with the aim, on the one hand, of examining the suitability of such ranges when a macroscale approach is adopted, while, on the other, investigating their capability in predicting the real behavior of masonry structures. The comparisons are performed in terms of failure mode, initial stiffness, maximum horizontal load and ultimate drift. The results provide a critical appraisal of the predictive capability of the considered models. They also show that the application of material parameter ranges based on typological features to numerical models may be problematic and entails a limited improvement in the predictions compared to the analytical formulations.

In the context of the structural safety evaluation of masonry arches under both gravitational and seismic loads, this study analyses the possibility to apply fast-assessment methodologies, aimed at defining intervention priorities through the proposal of typological abacuses. With this aim, two automatic VBA (Visual Basic for Application) procedures have been implemented and adopted to estimate the capacity of six configurations (from semi-circular to pointed) of stand-alone masonry arches to withstand vertical loads, and to calculate the horizontal load multiplier, related to the in-plane seismic capacity. The developed subroutines are based on the Uniqueness theorem of Limit Analysis, so that a static and a kinematic approach have been adopted, respectively, for the estimation of the maximum vertical load, compatible with the geometric features, and the evaluation of the horizontal capacity. Subsequently, both procedures have been applied to a wide range of arches by means of a parametric study. The results thus obtained allow the definition of typological abacuses for the preliminary safety assessment of the investigated structural types.

In the current paper, a study aimed at assessing the seismic vulnerability at a regional scale of existing masonry churches based on a typological methodology is proposed. In particular, the study refers to the Abruzzi, which is an Italian region affected by a significant seismic hazard. Firstly, an accurate historical and typological characterization aimed at identifying the most widespread church typologies in this area is proposed. Hence, six main church samples have been defined based on recurrent geometrical and constructive features, namely two Medieval and four post-Medieval church types. Then, by adopting common assumptions for the definition of both geometries and mechanical characteristics of the masonry, numerical analyses have been carried out. To this purpose, six FEM Models have been implemented in order to operate specific comparisons between the analysed churches. In particular, a mass-proportional distribution of forces has been adopted and the attainment of the Damage Limit State for Artistic Asset (SLA) has been assessed. Despite the simplified hypotheses, the analysis has provided a good correspondence with damage scenario observed in churches that experienced the recent seismic events occurred in this area (i.e. L’Aquila 2009 and Central-Italy 2016–17). Moreover, the conducted comparison lays the groundwork for predictive aims and confirms that Italian post-Medieval churches are generally characterized by a higher vulnerability than the Medieval ones.

The component method provided by Eurocode 3 for the evaluation of strength and stiffness of beam-to-column joints is considered a very laborious procedure that is often difficult to apply. This is owing to the large number of geometrical and mechanical parameters involved in the analytical formulations. Hence, the component method is only seldom used for practical applications, with the consequence that the real behaviour of joints in terms of strength and stiffness is not accounted for. The aim of this paper is to provide an automatic tool that allows an easy-to-use application of the component method for the evaluation of beam-to-column joints stiffness and strength, and also enables plotting of the moment–rotation curve describing the joints' behaviour. Moreover, the proposed tool is used to carry out parametric analyses for two bolt-rows in end-plate beam-to-column steel joints. This is addressed to the definition of design charts for the optimal selection of joints.

In order to prove the possibility to adopt effectively metal shear panels for practical applications and to define specific design methodology, a case study, related to the retrofitting of the hospital building of Scafati in Campania, is presented in this paper. Based on the results of previous full-scale tests on a real r.c. frame reinforced with pure aluminium shear panels, a design procedure has been implemented in order to define the optimal configuration of shear panels to be applied to improve the seismic performance of the building under consideration. Then, a parametrical study by means of dynamic analyses under different historical records has been developed taking into account different hypotheses of modeling for the RC structure. The obtained results allows to confirm the effectiveness of the proposed system, which is able to increase significantly the seismic performance of existing structure. In addition, the outcomes of the study provide interesting indications for design applications.

This paper proposes an analytical formulation for designing dissipative metal shear panels for the seismic protection of buildings. In particular, two types of dissipative shear panels are analyzed. The first is based on the adoption of a material characterized by a low yield strength with the application of transversal stiffeners. The latter is a steel shear plate that is properly weakened by perforations. Both the studied typologies are conceived in order to obtain a low shear elastic strength, so that their dissipative function is activated when the other members of the structure are still in the elastic field, even for high intensity earthquakes. Moreover, they are usually designed in order to postpone the trigger of potential buckling phenomena to the field of high shear inelastic demands. The proposed design formulations put in relation demanded shear stresses and strains. In particular, a unique expression, characterized by different coefficients for the two panel typologies, is given. The validity of the proposed expression is corroborated on the basis of the results of several numerical and experimental analysis.

This paper deals with the seismic response of dual steel frames with and without dissipative metal shear panels. The main goal is to define possible design criteria, for the seismic protection of new and existing buildings, accounting for the main behavioral peculiarities of metal shear panels.To this purpose, based on a large number of historical records that are selected in order to match the main interesting frequencies, Incremental Dynamic Analyses (IDAs) are carried out on two steel frames. These frames have been first designed in order to satisfy specific performances. Then, they have been improved by imposing stricter design goals that have been complied with the application of dissipative metal shear panels.The obtained outcomes highlight that metal shear panels allow to control properly the collapse mechanisms of the frames. Moreover, they can lead to significant increases of collapse accelerations and to a general reduction of both the permanent and the transient story drifts. The paper concludes with the evaluation of the equivalent q-behaviour factor of both the protected and the un-protected frames. As it could be expected, the most effective shear panels are able to produce stronger increase of behavior factors (up to 150%), due to the larger dissipative capacity of the whole structure.

The seismic events occurred in Central Italy in 2016 caused severe damage to the monumental heritage and in particular to churches. The current study examines the effects on 68 one-nave churches located in Marche, Umbria and Lazio, based on a large number of post-earthquake inspections, which have been carried out within the activity of the Italian Consortium ReLUIS. To define the damage level in post-earthquake status, a macro-element approach has been adopted. The collected data have been processed in order to obtain Damage Probability Matrices (DPMs) for two separate groups of churches, which have been defined according to different occurred levels of macro seismic intensity. Then, according to the methodology proposed by the Italian Guidelines on cultural heritage, a vulnerability index has been determined for each church, taking into account the presence of fragility indicators and antiseismic devices. Finally, the expected damage level has been evaluated using a first level predictive model, allowing a comparison with the observed damage, as it was detected after the earthquake. The obtained outcomes prove that the adopted predictive model is quite reliable for reproducing actual damage scenarios.

The extension of damage on churches observed after strong earthquakes stresses the need to define suitable speedy methods for the assessment of the main sources of structural fragility for these constructions. This paper presents a methodology for seismic vulnerability assessment of churches based on a damage reconnaissance activity carried out after the 2009 L'Aquila earthquake on a population of 64 churches. Firstly, the post-earthquake evaluation of damage is described aiming at identifying recurrent damage mechanisms. It has been observed that the occurred damage scenario, shown through damage probability matrixes, can be represented by a binomial distribution, which depends only on mean damage level. Then, a literature predictive model is applied for outlining fragility curves, which represent a useful tool for prediction of likely damage scenarios. Finally, some ongoing applications of the proposed analysis methodology to churches of different territorial areas are described.

The Italian cultural heritage is made of a large number of valuable historical masonry constructions characterized by several chronological, typological, constructive and structural peculiarities. Old masonry churches surely are the most important asset of this heritage. Lessons learnt from past earthquakes emphasize the necessity to establish effective methodologies for the seismic vulnerability assessment at large scale and for defining possible risk mitigation strategies. Based on this premise, this paper aims at calibrating a procedure for assessing a vulnerability index of churches. This procedure is based on the damage provoked by the 2009 L’Aquila Earthquake, with particular reference to three nave churches located in Sulmona-Valva and L’Aquila Dioceses in Abruzzi. In a first step, the damage scenario provoked by the considered event is presented in terms of Damage Probability Matrices. Then, a procedure for assessing the expected damage is properly calibrated in order to reproduce the real damage scenarios observed on the churches under investigation. After its calibration, the model is applied to define suitable fragility curves.

The current study focuses on the effects of the seismic events occurred in Central Italy on 2016, which caused in this area unacceptably losses of human life and severe damage to the building stock and monumental heritage. The main aims of this article are first to provide a qualitative picture of damage observed on 68 one-nave churches located in Marche, Umbria, and Lazio, and then to assess the possibility of using an approach based on Peak Ground Acceleration (PGA) for predictive purposes. Based on a large number of post-earthquake inspections, which have been carried out within the activity of the Italian consortium ReLUIS, Damage Probability Matrices have been obtained by adopting a macro-element approach. It has been applied to both single damage mechanism and for assessing the global damage of the examined churches. Finally, an expected damage level has been evaluated using a first-level predictive model as a function of vulnerability indexes, allowing a comparison with the actual damage revealed after the earthquake. The obtained outcomes prove that the predictive model is quite reliable for reproducing the damage scenario of churches spread over a large territory, provided that the PGA level is used as a measure of earthquake intensity.