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The S. Nicolo l’Arena Exedra in Catania was built up in 1722 in front of the homonymous Monastery. The facade is composed by natural and artificial stones: Syracuse stone for portals and windows frames, lava stone for the basement and a reddish plaster for plane surfaces, typical materials of the Catania historic buildings. Its color is due to the introduction of the so-called “ghiara” in the finishing mixture. A multi-technique study is here presented: after the obtainment of a detailed surveying of the building surface through the integration of 3D laser scanner and digital photogrammetry techniques, FTIR-ATR, Raman and XRD analysis were carried out to characterize structures, materials and their alteration products.

The seismic assessment of archaeological heritages is studied by means of 2D numerical analysis with Discrete Element Method (DEM). The proposed approach is based on a refined discretization that reproduces the effective block masonry pattern and on a routine for carrying out seismic analysis according to either quasi-static or dynamic approaches. The applicability of the DEM for the analysis of archaeological heritages is discussed referring to the case studies of the south-east edge of the external wall of the Colosseum that was restored by Stern in 1807, and the arcades of the Claudio Aqueduct in Rome. The analyses based on DEM provide a reliable estimate of the seismic capacity and a refined representation of the expected failure mode, while also contributing to the design of appropriate strengthening measures. The approach is finally validated through comparison between the outcome of the numerical simulation and the survey of the existing crack pattern of the monuments.

Recent Italian earthquakes (L’Aquila 2009, Emilia 2012, Central Italy 2016–2017) have shown the high vulnerability of existing and historical masonry constructions to seismic actions. This ...

The nonlinear methods of analysis are the most indicated ones to carry out the vulnerability assessment of existing Reinforced Concrete (RC) buildings. Notwithstanding nonlinear approaches strongly depends by the knowledge level of building, they allow to obtain the effective response of structure, due to the combined effect of both dead and seismic loads. However, these methods are based on conventional choices that, in some cases, can modify the results that are affected of a significant uncertainty level. Concerning to nonlinear static method, one of the fixed point at the base of analysis is the choice of control node (point in which the displacement of the structure under horizontal load is monitored) coincident with the centre of mass of last storey of building. This assumption is significant when, in order to verify the structural capacity with N2 method, an equivalent Single Degree of Freedom (SDoF) system is considered, neglecting the real variability of centre of mass position, provided by the accidental loads. In the present work, it will be shown as the structural capacity (in terms of displacement at Life Safety Limit State) with reference to several cases of existing RC buildings can be strongly affected by the choice of the control node position. In particular, 28 existing RC buildings were analysed. These are part of a large sample of example cases made according to geometric and mechanics features of real existing buildings. The peculiarity of the “ideal” buildings consist in an irregular in-plan shape but with dynamic properties such as to allow the applicability of pushover analysis and, consecutively, the application of N2 method. In order to optimize the procedure of choice of control node, a parametric formulation is proposed, depending by dimensionless geometric features, able to estimate the variability of capacity curve at variation of control node position. This approach is mainly finalized to expeditious estimate of structural behavior for RC buildings of urban aggregate and it is a base for formulation ad hoc to evaluate the structural response of dynamic irregular buildings.

The article presents the results of an experimental and numerical investigation on Azzone Visconti bridge, a 14th century arch bridge in Lecco (northern Italy). Starting from the historical data an...

The wind is the most destructive natural phenomenon. Its actions are thus crucial for the safety and cost of construction. Their evaluation is a cornerstone of civil engineering and a societal need for safety and economy. Wind Engineering is best defined as “the rational treatment of interactions between wind in the atmospheric boundary layer and man and his works on the surface of Earth”. The International Association for Wind Engineering promotes international co-operation among scientists, engineers and other professionals for the advancement of knowledge in the broad field of Wind Engineering. The study of the wind loading of structures is a main topic of Wind Engineering and even more the subject around which Wind Engineering was born and evolved. This paper provides a general framework, even if necessarily not exhaustive, of the main phenomena to which structures are exposed due to wind actions and the most appropriate analytical, experimental and numerical tools to evaluate and mitigate their consequences in order to make them safe, serviceable, sustainable and cost-efficient. This discussion is herein developed keeping in mind, as a reference point, the code provisions. The conclusions provide a synthetic overview of the emerging issues on which the research on wind loading is in progress worldwide.

The seismic vulnerability of city centers is commonly assessed by extending the study methods applied to single buildings to urban aggregations. This approach is not always applicable at territorial scale, as it is uneconomical in terms of time and costs. An innovative method provides reasonable large-scale a priori estimation of parameters not directly evaluable from the exterior of buildings by elaborating values which can be measured from the outside. Those parameters are treated as continuous variables, by assigning them a suitable probability density function. The Bayesian approach is adopted, which allows the update of initial hypotheses by using new data gathered during on-site surveys. In this regard, a rapid survey form for the on-site data collection is proposed. An example of its application to a facade of a building structural unit in Santo Stefano di Sessanio in L’Aquila province (Italy) is proposed, showing promising preliminary results for buildings belonging to Italian historical c...

Over the years, historic unreinforced masonry vaults have been proved to be particularly vulnerable to dynamic actions and large displacements. This paper focuses on the investigation of the structural behaviour of a pavilion vault on spreading supports by means of experimental tests on a 3D–printed scale model made of discrete blocks. Both the collapse mechanisms and the ultimate displacement capacity are analysed. The reliability of this method for investigating the collapse of vaulted structures is validated by drawing analogies with crack patterns of real vaults. The experimental data are compared with the results obtained by thrust line analysis. A good prediction is obtained by making specific assumptions that take into account three-dimensional effects, which demonstrates the importance of thrust line analysis also for 3D collapse.

The recent work by Mark Wilson Jones addresses a fundamental topic: the explanation of the reasons of classical architecture, its legacy, its everlasting success in Western architecture, the reflections of its archetypes in contemporary culture (and not only in architecture).

This article investigates the influence of natural organic materials on the properties of traditional mortars. Mortar specimens produced with two binders (natural hydraulic lime and aged lime putty) with the same sand and three different organic additives (linseed oil, brown sugar, and cow's milk, with different percentages) were created. The color variations (colorimetry), waterproofing behavior (water capillarity test), permeability (water vapor permeability test), mechanical properties (maximum resistance to compression test), mineralogical composition (X-ray diffraction), and optical properties of mortars (transmitted light microscopy, UV fluorescence microscopy), and carbonation using a phenolphthalein indicator, were evaluated after 28days, 3, 6, and 12months.In this article, we highlighted a series of transformations induced by the additives: a strong modification of colorimetric parameters, a general hydrophobic effect of milk and oil not linked to a total occlusion of porosity, a decrease of mechanical parameters in the specimens prepared with hydraulic lime with respect to the specimen without additives, a different distribution and shape of macropores, a different level of carbonation.This article also describes the role of the preparation methods in the influence of natural organic materials on the properties of traditional mortars.

Purpose The aim of this research is to give to construction industry stakeholders some Key Performance Indicators (KPIs) able to help them making the best decisions when acquiring, operating, maintaining and repairing a building. These KPIs are intended to be included inside a Building Condition Assessment procedure developed by the authors. Approach This work is mainly based on two types of KPIs: one, here called Technical index, to assess building degradation and maintenance, so to have a measure of how the asset is getting older; and another, here called Documents index, to measure the quality and quantity of available building documents and thus to know if the building fulfils its legal requirements. Findings The proposed KPIs give a picture of the asset current condition, a measure of how it is maintained, the list of its pathologies and also an indication of missing documents. Research limitations The KPIs developed are meant to help survey an asset with only visual inspections. In case one or more serious problem are detected, a specific analysis may be required, no matter the final value of the KPIs. Practical implications The knowledge about built assets given by these KPIs will help stakeholders in making the best decision when operating or deciding to buy an asset. Originality KPIs and Building Condition Assessment procedure are the outcome of an original research that had the purpose of developing instruments for a reliable but quick evaluation of assets condition, to be performed before acquiring them or making major decisions about their refurbishment.

Despite the high vulnerability of historic structures to earthquakes, the approaches for evaluating seismic demand and capacity still appear inadequate and there is little consensus on the most appropriate assessment methods to use. To develop an improved knowledge on the seismic behavior of masonry structures and the reliability of analysis tools, two real-scale specimens were tested on a shake table, and several experts were invited to foresee failure mechanism and seismic capacity within a blind prediction test. Once unveiled, experimental results were simulated using multi-block dynamics, finite elements, or discrete elements. This article gathers the lessons learned and identifies issues requiring further attention. A combination of engineering judgment and numerical models may help to identify the collapse mechanism, which is as essential as it is challenging for the seismic assessment. To this purpose, discrete modeling approaches may lead to more reliable results than continuous ones. Even when the correct mechanism is identified, estimating the seismic capacity remains difficult, due to the complexity and randomness of the seismic response, and to the sensitivity of numerical tools to input variables. Simplified approaches based on rigid body dynamics, despite the considerable experience and engineering judgment required, provide as good results as do advanced simulations., info:eu-repo/semantics/publishedVersion

We report on a historical study and on the evaluation of the structural performance of an innovative vaulting system developed in the 17th and 18th centuries. This peculiar construction tec...

Purpose Several countries have carried out air quality monitoring in professional workplaces where chemicals are used. Health-care spaces have been less investigated. This paper aims to define a protocol, as developed by a research group, for inpatient rooms to understand the state of the art and to suggest design and management strategies for improving process quality. Design/methodology/approach Starting from the ISO-16000 standard and guidelines for monitoring activities, a protocol is defined for a one year investigation, with passive samplers. Through data analysis of the investigations and analysis of the cleaning and finishing products, heating, ventilation and air conditioning and maintenance activities, etc., it is possible to highlight the potential influences of chemical pollution. Findings A methodology is defined for understanding the chemical pollution and the possible factors related to construction materials, cleaning products and maintenance activities. Research limitations/implications The paper analyzes only a limited number of case studies because the monitoring activity is still in progress. Practical implications The investigation offers a starting point for a wide tool for the definition of design, maintenance and management strategies in health-care facilities. Social implications The research project, aimed at improving the knowledge of indoor air quality (IAQ) in inpatient rooms, is a starting point for a supporting tool for future regulations concerning health-care facilities. Originality/value IAQ is an issue on which many governments are focusing. Several health-care researchers have reported studies that aim at improving users’ health. Most investigations are about biological and physical risks, but chemical risks have been less studied. The paper suggests some design and management strategies for inpatient room.

Newly emerging relationships between form and function reveal the increasingly complex nature of metropolitan regions. The present study investigates spatial diversification in settlement forms and socioeconomic functions in metropolitan Attica (the administrative region including Athens, the capital of Greece), with the aim of implementing a holistic framework assessing urban complexity in contemporary cities. Taken as key components of urban complexity, morphological and functional diversity have been analysed using multi-domain indicators that describe settlement characteristics (land-use, soil sealing, building use, vertical profile of buildings, building age, construction materials) and socioeconomic functions (economic base, working classes, education levels, population age structure, composition of non-native population by citizenship, distribution of personal incomes), thus providing a comprehensive description of local-scale diversification in urban structures. A correlation analysis was used to verify the spatial coherency between individual dimensions of urban diversification. Analysis of global Moran’s spatial autocorrelation index reveals specific gradients of urban diversification that discriminate morphological attributes from socioeconomic functions. Municipalities were profiled on the basis of Pielou’s evenness indexes for each urban dimension: a factor analysis indicates latent patterns characterizing areas with high and low diversification in metropolitan functions. Urban and rural municipalities were, respectively, characterized as the most and least diversified in the study area, with peri-urban municipalities ranking in-between, evidencing a diversification gradient correlated with the distance from downtown Athens. A multidimensional analysis of the most relevant dimensions of metropolitan complexity has proved to be a promising tool for monitoring urban gradients, polycentric development and (latent) socioeconomic transformations in contemporary cities.

The international scientific community believes unequivocally that, at the origin of the climate change, there are anthropic factors mainly linked to the construction sector and to the disproportionate use of fossil energy sources. The selection of building materials plays a key role in the reduction of energy consumption, especially in the Mediterranean area, where the internal overeating risk is high if the solar radiation is not controlled and the free supply of internal heat is poorly managed. Traditionally, in the Italian context, the slab-on-ground floor is made in concrete or more rarely in stone. However, it is usually recommended to minimize the use of concrete as it has a strong environmental impact, reinforced concrete is still the most recommended solution for foundations, both for regulatory and practical reasons. The present study proposes a methodology for the design of high efficiency slab-on-ground floor for warm climate through optimization code performed with the software modeFRONTIER. Starting from the traditional floor structures, the multi-objective methodology stands as an advanced step for the identification of new configurations, favoring the management of many variables, such as thermal, environmental and economic aspects. The results are characterized by high presence of local and eco-friendly materials and reduced costs. At the end, this work demonstrates that it is possible to obtain high performance solutions with also very few numbers of layers.

The hygrothermal behaviour of the opaque building envelope (facades and roofs) is a topic worthy of investigation for the scientific community, especially in consideration of changes in construction techniques and lifestyle habits. For the presence of waterproofing layers, placed in the outer part of a structure, hygrothermal behaviour of flat roofs is of particular interest. In this paper, an original analytical model for evaluation of the hygrothermal behaviour of ventilated flat roofs is proposed. In particular, the authors provide a method for assessing the ventilation air flow rates necessary to avoid interstitial condensation in flat roofs. Dependency of the necessary ventilation air flow rates on geometrical, thermophysical, and climate parameters is investigated and discussed. After a simplified analytical treatment applicable to any type of ventilated flat roof, some examples are shown, referred to study cases of flat roofs that are very widespread in Italy. The results obtained by the authors and discussed in the paper can be useful for architects and building engineers during the early design stage of buildings.

Open-plan offices have lower construction costs, allowing for significant savings in space and, according to designers, facilitate communication between workers, thus, improving collaboration, as well as the exchange of ideas. For these reasons, this type of office has become widespread, while highlighting numerous limitations and various problems. These include the control of anthropic and electromechanical noise. In this study, measurements of the noise emitted by a heating, ventilation, and air conditioning (HVAC) system were carried out in an open-plan office. The average spectral levels in a 1/3 octave band were compared through correlation analysis, to identify any redundant data. A model was then adapted to evaluate the importance of the variables, in order to classify the characteristics, by importance. To reduce the number of predictor variables, a selection analysis of the characteristics was carried out. A subset of predictors was extracted to be used to produce an accurate prediction model. Finally, a model based on recursive partitioning, to detect the operating conditions of an HVAC system, was developed and applied, so as to provide insights into the development and application of this technique, in these contexts. The high accuracy of the model (Accuracy = 0.9981) suggests the adoption of this tool for several applications.

Smart building applications require a large-scale deployment of sensors distributed across the environment. Recent innovations in smart environments are driven by wireless networked sensors as they are easy to deploy. However, replacing these batteries at scale is a non-trivial, labor-intensive task. Energy harvesting has emerged as a potential solution to avoid battery replacement but requires compromises such as application specific design, simplified communication protocol or reduced quality of service. We explore the design space of battery-free sensor nodes using commercial off the shelf components, and present Pible: a Perpetual Indoor BLE sensor node that leverages ambient light and can support numerous smart building applications. We analyze node-lifetime, quality of service and light availability trade-offs and present a predictive algorithm that adapts to changing lighting conditions to maximize node lifetime and application quality of service. Using a 20 node, 15-day deployment in a real building under varying lighting conditions, we show feasible applications that can be implemented using Pible and the boundary conditions under which they can fail., 4 pages, 4 figures, BuildSys '18: Conference on Systems for Built Environments, November 7--8, 2018, Shenzen, China

The fortress of Arnara is a small castle in a high seismic hazard zone in Latium, Italy, which represents a landmark for the local population. It was chosen as a case study, being a perfect example of Middle Age fortress, well preserved during the centuries despite some strong earthquakes damaged it in the past. The project presented here is a significant example of how the interest of a community to regenerate an ancient structure for its re-use can pave the way to a complete structural strengthening, which includes anti-seismic concepts aiming at retrofitting the ancient fortress walls. The overall project joins architectural and structural solutions. The architectural solution aims at a functional reconfiguration of the spaces, so to attract the locals to reuse it, while at the same time highlighting some valuable architectural features of the fortress. The structural solution aims at improving the seismic resistance of the masonry walls with a structural intervention that is respectful and int...

Unreinforced masonry (URM) cavity-wall construction is a form of masonry where two leaves of clay brick masonry are separated by a continuous air cavity and are interconnected using some form of tie system. A brief historical introduction is followed by details of a survey undertaken to determine the prevalence of URM cavity-wall buildings in New Zealand. Following the 2010/2011 Canterbury earthquakes it was observed that URM cavity-walls generally suffered irreparable damage due to a lack of effective wall restraint and deficient cavity-tie connections, combined with weak mortar strength. It was found that the original cavity-ties were typically corroded due to moisture ingress, resulting in decreased lateral loadbearing capacity of the cavity-walls. Using photographic data pertaining to Christchurch URM buildings that were obtained during post-earthquake reconnaissance, 252 cavity-walls were identified and utilised to study typical construction details and seismic performance. The majority (72%, 182) of the observed damage to URM cavity-wall construction was a result of out-of-plane type wall failures. Three types of out-of-plane wall failure were recognised: (1) overturning response, (2) one-way bending, and (3) two-way bending. In-plane damage was less widely observed (28%) and commonly included diagonal shear cracking through mortar bed joints or bricks. The collected data was used to develop an overview of the most commonly-encountered construction details and to identify typical deficiencies in earthquake response that can be addressed via the selection and implementation of appropriate mitigation interventions.

A number of constitutive models are nowadays implemented in numerical codes which simulate the stress–strain behaviour of soil from very small to large strain. In this paper, the mechanical behaviour of Leighton Buzzard sand (grade E), used worldwide for physical modelling, has been thoroughly characterized by laboratory testing along several stress paths. Tests were aimed at calibrating a constitutive model, that allows considering stiffness nonlinearities in a wide range of strains, in the framework of isotropically hardening plasticity. As a validation, the results of dynamic centrifuge tests on a layer of the same sand were compared with finite element predictions.

Zero-energy and zero-carbon buildings would be a huge opportunity for contrasting the climatic changes and, more in general, the deterioration of the microclimate inside and around cities. About it, a question appears compulsory: are zero-energy and zero-carbon concepts applicable at urban scale? This paper tries to answer to this question, by discussing the possible effects of the application of appropriate city planning techniques when a new settlement is designed. An integrated approach to urban planning is applied to a case study, for promoting the design of buildings with very low (or zero) energy needs, characterized by high indoor comfort conditions, by taking into consideration whole city areas, with different kinds of services. Passive heating, cooling and daylighting techniques have been combined, as well as the integration of renewable sources, in order to minimize the energy demand and environmental impact, for having a sustainable ‘urban balance’ and, in general, a sustainable urban growth. As real case study, the design of the holiday village ‘Olympiad’ is presented; it should be built in an unstructured seaside area in Greece. Several indexes are introduced to evaluate the global sustainability of the settlement, through the application of the definition of ‘on-grid ZEB’, with reference to each building as well as for the entire village. This kind of research could help city planners for a growth inspired to general goals of urban sustainability.

Persian architecture is characterised by shapes and patterns, which can be analysed through mathematical models. Beside 2D patterns, many of the traditional geometric ornaments are realised on 3D surfaces such as domes or vaults. Literature mainly addresses the 3D problem by means of a 2D scheme, which is an important and synthetic representation but is not exhaustive and lacks of clarity. This paper proposes a framework based on the integration of 2D drawings, as in the traditional approach, and a photogrammetric 3D model based on a sample of standard resolution images (tourist pictures). The framework is tested on a muqarnas, a characteristic Persian ornament, in order to study and analyse its modular design and hierarchy of elements. As a case study, the entrance iwan of the Shah Mosque in Isfahan, Iran, is considered. The result is a link between the 3D patterns and the geometry of architectural elements, which completes and overcomes their schematic 2D representation.

An analytical structural study of helicoidal masonry stairs made of monolithic steps, built in torsionally at their external boundary, and supported on an inner rib, is presented. The results of the analysis are applied in particular to the case study of the triple helical stair of San Domingos de Bonaval. The analysis is based on the assumption that the material of the rib is unilateral, namely a no-tension material in the sense of Heyman; in particular the safe theorem of Limit Analysis is employed. In the spirit of the safe theorem the structure is stable if a statically admissible stress field can be constructed. For the unilateral material employed here, singular stress fields, that is stress concentrated on lines (arches) are allowed. The statically admissible stress fields here constructed, combining concentrated stresses and 2D diffuse uniaxial stresses, are purely compressive and balance the transverse loads.

The construction of the Baptistry of Saint John has a debated and uncertain history; the hypothesis on its main construction phases may span from the Roman period to the 13th century, according to different authors. This uncertainty is mainly due to the lack of primary sources and certain dating issues. By combining dendrochronological analysis and radiocarbon dating, some light was shed on the building’s history. Open at least from 897, in 1059 Pope Nicholas II re-consecrated the baptistry after several renovations. Around that period, the octagonal dome was probably built by using chestnut beams to tie the structure together. The dendrochronological analysis dated the silver fir element to 1268. This element possibly represents a replacement coincident with the period, between 1270 and 1300, when a substantial part of the mosaics of the dome was positioned.

Composite steel–concrete beams represent an efficient form of construction for building and bridge applications. In this structural arrangement, the composite action is provided by means of a shear connection placed at the interface between the steel beam and the concrete slab, and this is commonly specified in the form of shear connectors. In this system, the structural rigidity is dependent on the deformability of the shear connection and this kinematic condition is usually referred to as partial shear interaction. In this context, this paper presents a theoretical model to study the partial shear interaction behaviour of composite steel–concrete beams in the framework of GBT. The effects of longitudinal slip between the concrete slab and steel beam are accounted for by taking into account the deformability of shear connectors during the evaluation of the warping components of the deformation modes. The proposed approach falls within a category of cross-sectional analyses available in the literature for which a suitable set of deformation modes, including conventional, extension and shear modes, is chosen from dynamic analyses. This method is applicable to open, closed and partially-closed cross-sections with one or more shear connections. A numerical example of a composite bridge is presented, with the results validated against those obtained from a shell finite element model developed in ABAQUS/Standard. The effect of different finite elements used in the GBT cross-sectional analysis is considered, in particularly highlighting how they influence the stress distributions induced in the composite section.

Resilience is defined as the capacity of a system to cope with impacts by minimising their effects (through adaptation and mitigation). In practice, upstream measures on the causes, in terms of reducing the emissions or using resource more efficiently, should constitute the main action strategy for reducing the environmental impacts. The article describes the results of a research aiming at quantifing the average environmental impacts associated with the current housing stock in Europe through the construction of statistically-based representative models and the application of the Life Cycle Assessment (LCA) method. Knowledge of the characteristics and the environmental performances of the building stock – particularly the residential building stock – is of fundamental importance to establish effective policies and priority actions for the prevention of impacts and the strengthening of the resilience., TECHNE - Journal of Technology for Architecture and Environment, TECHNE 15 (2018): Architectural resilience

New perspectives and frontiers were highlighted in a Special Issue on "Real Estate Economics, Finance and Investments". The twenty-eight papers that were selected and published emanated from scholars from universities all over the world with the aim to represent more recent advances in building management, mass appraisal methods, real estate risk management, economic evaluation of real estate investment projects, real estate market, property, social housing, real estate economics, real estate finance, building transformation and economic effects on environment. These papers helped to determine a unique and valuable opportunity to experiment with multiple approaches to these ever more crucial topics. This note proposes a brief review of the twenty-eight papers, concluding with some reflections about policy, practice and research on real estate issues.

This article looks at a knowledge-based approach to emergency situations caused by earthquakes or other natural disasters, and illustrates how a multidisciplinary approach enables the integration of technical requirements with those of a historical and cultural nature. The case study presented is the recovery of the ex-city hospital of L’Aquila, in Italy, which was hit by an earthquake in 2009. The integrated use of varying investigation methodologies allowed us to establish the effectiveness of a knowledge-based approach, and generated new ideas for the development of the structure and its strategic role within the city.

This paper presents a different point of view on the conservation of the built heritage, adding ionizing radiation to the most well-known digital documentation dataset. Igneous building materials characterize most of the built heritage in the Campania region, and in a large part of southern Italy. The ionizing radiations proceeding from these materials can produce stochastic biological effects on the exposed living beings. The research team designed and tested a technical-scientific protocol to survey and analyse this natural phenomenon in association with the use of geological material for building purposes. Geographical Information Systems (GISs), City Information Modelling (CIM), and Building Information Modelling (BIM) are the digital tools used to manage the construction entities and their characteristics, and then to represent the thematic data as false-colour images. The emission spectra of fair-faced or plastered materials as a fingerprint of their nature is proposed as a non-invasive method. Due to both the huge presence of historical buildings and an intense touristic flow, the main square of Pompei has been selected as a study area.

In the paper is presented a research study on floor system behavior in existing Reinforce Concrete (RC) buildings under horizontal actions. Generally, vulnerability analysis consists in the study of effective structural behavior of buildings, in order to carry out the assessment, comparing seismic demand and structural capacity. To this purpose, the hypotheses at the base of Finite Element (FE) numerical model, as rigid floor assumption, assume a primary role for the accurateness of seismic analysis results. In the study, after carrying out a preliminary assessment on significant parameters, which influence the floor stiffness, a new numerical simplified procedure has been proposed. Starting by micro-models, made with solid elements, on several simple applications, the behavior of floor system in elastic field has been analyzed in terms of in-plane displacements and a thickness of an equivalent shell of orthotropic material has been defined, usable in macro-model of frame-shell elements. Subsequently, using the procedure proposed, a real case of existing RC buildings has been investigated. The results of linear analysis have been evaluated through their comparison with those obtained by a model where the flexibility of slab is simulated with a more consolidate method like “strut model”. The numerical analyses carried out have enabled to give interesting indications about both the accuracy of rigid floor assumption and assessment of slab elements.

Torsional effects may significantly modify the seismic response of a building and the distribution of damage throughout the structure. In this paper, the torsional response of a case study Reinforced Concrete (RC) wall-frame building built between 1960 and 1980 is presented. The building was constructed without considering appropriate seismic design criteria and without taking into account the forces induced by torsional vibrations. A numerical investigation on the seismic behaviour of the case-study building is carried out by means of nonlinear static pushover analyses performed on a 3-D numerical model of the building; the Extended N2 method is adopted to take into account the influence of higher mode effects in plan and in elevation. The results are then compared with the ones obtained from nonlinear Time-History (TH) analysis. It is concluded that the shear demand evaluated according to the Extended N2 method provides a conservative estimate in comparison to TH analysis. Thus, an improved procedure is proposed for the application of the Extended N2 method in the evaluation of shear demand.

This paper concerns the investigation of the behaviour of sandwich beams previously tested in four point bending through analytical and numerical models. Modelling is a fundamental resource to predict the mechanical response of the element and to investigate the mechanisms that act during the evolution of the test. The sandwich beams here taken into account are characterised by external textile reinforced concrete (TRC) layers and an insulation material (expanded polystyrene, EPS) able to transfer shear stresses. Bond between the layers is obtained during production thanks to an in-pressure casting technique, and no particular device is used in order to transfer shear stresses between the layers. Two beam slenderness values are taken into account. An analytical and a numerical approach have been used in order to predict the experimental behaviour: concerning the analytical approach, a model based on the Stamm and Witte sandwich theory has been developed including material non-linearity ; concerning the numerical analysis, a finite element (FE) model has been built in ABAQUS including material and geometry non-linearity. The assumption of perfect bond is used in both cases. The non-linear analytical and finite element models have been validated, as a good agreement with experimental results has been achieved. The experimental identification of material parameters - TRC in tension, mortar in compression and EPS in tension, compression and shear - is crucial for the definition of proper constitutive laws for the models and is here presented and discussed. For both approaches, the assumptions of modelling TRC in bending as homogeneous and assuming perfect bond between TRC and EPS (even when behaviour becomes highly non-linear) have been proved to be reliable. Analytical and FEM results show that EPS non-linear behaviour and TRC membrane and bending behaviour govern the response. The FE analysis also highlights the mechanisms involved in specimen failure .

An experimental campaign and a numerical analysis devoted to the investigation of the out-of-plane behavior of masonry walls reinforced with Fiber Reinforced Cementitious Matrix (FRCM) are presented here. The main goal of this study is to analyze and evaluate the effectiveness of the strengthening system, by discussing failure modes and capacity of strengthened masonry walls, in order to assess their behavior under out-of-plane horizontal actions, such as, for example, seismic actions. A purposely designed experimental set-up, able to separately and independently apply an axial force and out-of-plane horizontal actions on masonry walls, was used. Experimental results are discussed and compared with the outcomes of nonlinear analyses performed on simplified finite element models of the walls. A proper evaluation of the flexural capacity of FRCM strengthened walls is the first step of the ongoing process of drawing reliable code guidelines leading to a safe design of strengthened masonry structures.

It is well-known that the degree of saturation is a soil state condition able to represent the hydrological response of a shallow soil to weather conditions. One of the oldest models that referred on the degree of saturation to carry out the slope stability analysis at different scales, was the Shallow Landslide Instability (SLIP) Model. This paper shows how the SLIP model can be used to derive a simplified method to estimate multiple seasonal cycles of the mean degree of saturation of soil and to carry out the time-varying stability analysis of a test site slope. The simplified method to assess the degree of saturation uses easily available climatic data, such as air temperature and rainfall depth, and is validated through the comparison with long-term field measurements on a slope in Canneto Pavese, northern Italy. The SLIP model is also applied to obtain the safety factor of the slope, that was subjected to a rainfall-induced shallow landslide during the field monitoring period. Comparisons between field measurements and model outputs are used to validate the capability of the model of predicting both the mean degree of saturation of the topsoil and the observed unstable condition.

Le città rappresentano oggi il fulcro delle trasformazioni umane, sistemi estremamente complessi e sofisticati, ma al contempo vulnerabili. Oggi, infatti, eventi estremi, di origine naturale od antropica, minacciano più che mai le città, laddove elevatissima è l’esposizione della società contemporanea. Il governo delle città e del territorio, ovunque nel mondo, passa attraverso la mitigazione e la gestione dei rischi, agendo attraverso il governo sia dell’ambiente fisico che sociale delle città. La città infatti può essere interpretata come un sistema complesso di relazioni dinamiche tra il suo ambiente fisico costituito dalle infrastrutture, dagli spazi, dalle reti (comunicazione, trasporto, energia) dalla natura esterna, ed il suo ambiente sociale, costituito dalle comunità e dalle relazioni sociali che le governano. La gestione dei rischi e dei disastri è quindi un passaggio obbligato nell’attuale concezione del governo del territorio, che muove proprio dal sistema fisico e dal sistema sociale delle città.

The 2010–2011 Canterbury earthquake sequence provided extensive evidence of the significant seismic vulnerability of New Zealand unreinforced masonry (URM) churches. Given the high seismicity of th...

The study of the buckling behavior of large shell structures through full-size tests can be complex and expensive. Therefore, scaled structures are often preferred to investigate the buckling behavior efficiently. However, it can be difficult to design scaled structures that are representative of the full-scale structures. Herein, an analytical scaling methodology for compression-loaded sandwich composite cylinders based on the nondimensionalization of the buckling equations is presented. The methodology is used to develop scaled configurations that show a similar buckling response. Both the baseline and the scaled configurations are verified by finite-element analysis. Limitations of the methodology are discussed and are a result of neglecting the flexural anisotropy and the transverse shear compliance.

Radiative heat exchanges inside buildings remarkably affect the thermal balance of the human body in confined spaces and the related thermal comfort sensations of people. The mean radiant temperature is an important component of this balance. Unfortunately, it is usually computed by means of too simplified relationships, which significantly influence the comfort evaluations. Such simplified approaches are also accountable for a less effective design of HVAC systems which, in turn, could result in high energy consumption in the climatization of buildings. However, an accurate evaluation of the mean radiant temperature, especially when high intensity sources are present in a given internal space, depends on the angle factors between human subjects and surrounding surfaces of the enclosure. Angle factors, in turn, are direct functions of the projected area factors of the human body. Presently, there is still a certain lack in the availability of simple and reliable methods for computing angle factors of people in assigned postures, particularly in case of complex geometry and presence of heat high intensity sources, like sun. A comprehensive method is here introduced for evaluating the thermal comfort conditions of indoor spaces, avoiding the difficult singling out of several algorithms, dispersed in an inorganic way in the literature. A further contribution consists in the possibility of evaluating geometrically complex enclosures also in presence of direct solar radiation entering the room. Moreover, an analytical method for computing the projected area factors, based on experimental results, obtained by means of a photographic apparatus on purpose designed, is included in the methodology. An application of the method to a typical building situation in presence of direct solar radiation is also proposed.

In structural design the bending strength of heat-treated glass is in general calculated as the simple sum of the characteristic values of the strength of annealed glass and of the thermally-induced prestress, considered as the 5% quantiles of the corresponding statistical distributions. However, the probability that two stochastic variables attain small values simultaneously is quite low; therefore, it is expected that the 5% quantile of the heat-treated glass strength is higher than the simple sum of the 5% quantiles of the two constituent distributions. Here, we theoretically confirm this result by assuming a two-parameter Weibull distribution for the population of annealed glass strengths and a Gaussian distribution for the thermal stresses. Although recent studies have confirmed that the two-parameter Weibull distribution cannot properly interpret the left-hand-side-tail of the annealed-glass strength population, it is here shown that the statistical competition with the surface prestress lowers the importance of a very precise interpretation of the left-hand-side tail. Remarkably, since glass strength is governed by the opening of surface cracks in mode I, the expected statistical interference is strongly affected by the type of stress state. If the stress state induced by external actions is equibiaxial, all cracks have the same opening stress, but if it is uniaxial, many cracks will remain closed under the sole effect of the prestress, which is in general uniform and equibiaxial. The higher the surface compression is and the closer to the uniaxiality the stress state is, the higher the number of “not-active” cracks will be. We believe that this study will promote and guide the design of ad hoc experimental campaigns for experimental validation.

In this paper the problem of seismic vulnerability of masonry churches is analysed with reference to the Nativity of Blessed Virgin Mary ecclesiastic complex in Stellata of Bondeno (Italy). This religious construction is composed of a church, two bell towers, a cloister and the Saint Domenico´s oratory. The church, made of masonry brick stones, is characterized by a single hall with chapels, which is divided into three parts by arches, and has an apse elevated by a few steps with reference to the hall. The study herein presented is carried out according to the Italian Standards and Guidelines on Cultural Heritage. In a first step, the seismic risk coefficients both at Damage Limit State (α DLS) and Ultimate Limit State (αULS ) are evaluated by using the 3Muri calculation software for masonry structures . These coefficients indicate the ratio between the ground acceleration leading towards attainment of the two mentioned limit states and the PGAs of the site referred to a given reference return period. Afterwards, the variability of such coefficients is examined by changing both the masonry type and the seismic zone in order to detect the worst situations on the Italian land. In a second analysis step a comparison among the seismic risk coefficients αULS and the damage index calculated through a fast method provided in a suitable form by the Italian Civil Protection Department is proposed. Moreover, overturning mechanisms of facades are checked by using the 3Muri software with the ultimate goal to compare the predictive theoretical results with the real damages detected after the 2012 Emilia Romagna earthquake. Finally, in order to obtain a more precise assessment of the seismic behaviour of the church under study, linear and non-linear dynamic analyses are performed on a 3D FEM model setup through the ABAQUS software package.

Participatory Design has recently seen growing interest in developing critical forms of reflexivity able to disentangle the complexity of participatory ensembles. This article makes a methodological contribution to this endeavour. Drawing on socio-cognitive analyses of collaborative design, it proposes the frame of ‘interaction spaces’ as a scaffolding tool for conducting retrospective analyses of participatory design processes. The paper uses the ‘interaction spaces’ frame to analyse the three years of collaborative activities of the CIVIS Project. Through a longitudinal and multi-dimensional account of participatory dynamics involved in the designing, prototyping and testing of an IT platform for home energy management, the frame evidences how participatory configurations evolve over time; it makes clearer the characteristics of participation as partial and overtaken; and it identifies moments of cross-participation as potential basis for the boundary-spanning of design issues.

The objective of the work is to describe the design and the realization of a virtual simulator of a metropolitan railway cockpit, aimed at improving the perception of safety by means of tests made by users in Virtual Reality, analysed through statistical methodologies. The user lives the experience of a driver in an immersive and interactive Augmented Reality session, interacting with the train dashboard and all its control and signalling devices. In particular, the user is proposed to test different dashboards, different configurations of the controls and different signalling and safety devices in order to compare different concept and select the optimum in terms of perception of dangerous situation, reaction to an event and cognitive response in different situations of the rail vehicle driving. The simulator consists of a simulacrum integrating different technologies, physically composed of a dashboard of the cockpit of a metropolitan train and a real seat. The geometry of the dashboard has been acquired through Reverse Engineering techniques from a real train dashboard. The user’s immersion in the virtual environment during the simulation is guaranteed by the scene displayed on the Augmented Reality device, while, simultaneously, the stereoscopic projection on a screen above the dashboard makes available the experience even to users not directly involved, seeing the scene from the driver’s point of view. The immersive Augmented Reality is realized through a Head-Mounted Display (HMD) by which the user, protagonist of the driving experience, sees the configuration of the virtual control devices (CAD geometries) overlapped with the physical dashboard in order to naturally interact into the immersive environment. The interaction between user and simulator happens through the NUI (Natural User Interfaces) based on markerless tracking of parts of the user’s body.

Measuring and rating resilience of assets is a key enabler for asset and portfolio management. This paper presents a resilience rating system for buildings by utilising a Building Information Modelling approach. The assessment is carried out through a calculation following the Analytical Hierarchy Process. This methodology can be applied to different types of buildings, without a loss of precision or reliability. This resilience rating forms an integral part of more comprehensive array of Key Performance Indicators frameworks for asset and portfolio management, and therefore can significantly influence strategic investment choices for designers, engineers and building owners., TECHNE - Journal of Technology for Architecture and Environment, TECHNE 15 (2018): Architectural resilience

Historical centers are always composed of masonry building aggregates often designed without respecting seismic design criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behavior. For this reason, in this article the seismic response of structural units into masonry aggregates has been predicted through a simplified modeling approach. The implemented procedure has been calibrated on the results of a numerical model performed by using the Equivalent Frame Method (EFM), implemented within a Finite Element Method (FEM) calculation program, used to investigate a basic building compound representative of the constructive techniques developed in the past decades in the Southern Italy. First, the whole aggregate has been modeled and analyzed in the nonlinear static field in order to evaluate the seismic behavior of both intermediate and head structural units. Later on, the seismic response of these structural units, considered as isolated structures, has been assessed by considering in simplified way their position in the aggregate, as well as the influence of other constructions. Finally, the achieved results on the above single analysis cases have been compared with those deriving from the investigation of the whole building compound, allowing to confirm the effectiveness of the proposed novel analysis procedure.

The paper discusses a methodological approach for designing energy refurbishment measures basing on a deep energy diagnosis with in-situ measurements that allow the complete characterizations of building /HVAC system and the indoor conditions. Then, the Cost-Optimal approach is applied to compare several retrofit scenarios considering interventions both on the building envelope and on plant systems. The case study is a University building in heating dominated climate of South Italy. According to a macroeconomic perspective, with a discount rate of 3%, the package of energy efficiency measures that combines installation of heat recovery systems, regulation dispositive for HVAC and LED lamps with automatic control induces considerable energy saving and reduction of polluting emissions (−33%) as well as the largest reduction in the overall cost (−35%). Moreover, the importance to use validated models is examined exhaustively by proposing a sensitivity analysis on uncertainties due to modelling assumptions mainly referring to the adoption of stochastic schedules for occupant behaviour and equipment or lighting usage. First of all, this analysis shows that the calibration indexes are always dissatisfied; besides it is demonstrated that refurbishment design can appear more convenient, with wrong assumptions. For instance, one of proposed scenario brings to energy saving of −41% and reduction of global cost of around −36%.