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The Swiss code SIA 269/8 for the seismic evaluation of existing structures is risk-based. It relies on the compliance factor αeff, defined as the ratio of the seismic capacity of an existing structure to the required seismic capacity of a hypothetical identical new structure, to indirectly evaluate the casualty risk posed by the existing structure. While it is convenient to have a direct relationship between the casualty risk and the degree of code compliance of the existing structure, it is debatable if the contributions of the seismic hazard, structural performance and occupancy to the casualty risk should be merged into a single quantity, conflicting with the multi-component nature of seismic risk. This paper presents a graphical framework to evaluate the seismic fatality risk for existing buildings. The framework is based on the PEER Center performance-based earthquake engineering methodology to provide a transparent view of the contributions of different sources of hazard and risk. Starting from a seismic hazard model, probabilistic seismic demand, damage and loss models are introduced, taking the uncertainty into account at each step. The final product of the proposed framework, a loss curve representing the (annual) exceedance rate of fatality counts, enables engineers and building owners to make better, risk-based decisions. The proposed framework is demonstrated for an existing building in Switzerland. Notably, in addition to the SIA 269/8 evaluation method, this demonstration compares eight hybrid approaches differentiated by the utilized structural assessment techniques (nonlinear static pushover vs. incremental dynamic analysis), uncertainty propagation in the demand model (record variability only vs. record variability and epistemic uncertainty) and solution strategies (closed-form vs. numerical) to find a practical compromise between the accuracy and the computational effort. A comparison of the obtained results shows that the SIA 269/8 evaluation method underestimates the fatality risk for the presented building and identifies a practical alternative based on the proposed graphical framework., Bulletin of Earthquake Engineering, 22 (2), ISSN:1570-761X, ISSN:1573-1456

This paper introduces actual considerations on the progressive disuse of residential space in the Alpine territory, considering possible actions. Nowadays, the building complexes built around the 60s and 70s (symbol of the mass tourism) fell to be suffering and searching of a new identity: the generation of owners, who bought them, has aged and the propensities of the new generations for holiday in those places have changed, which, moreover, now offer fewer opportunities for leisure, particularly in winter. Due to the great attention (and seeming opportunities) of current incentive policies towards the energy improvement of the existing stock, authors investigate the private conveniences of transformations through the refurbishment of these buildings. Starting from the study of the territory and the dynamics of local population, the research analyses a possible set of energy works, based on the 110% Superbonus tax incentive, introduced by L.D. 34/2020. A large part of the insights is focused on technical and economic feasibility study of the possible actions, following a process based on the evolution of the legislation. The work carried out is based on a specific case study, located in a small municipality in Piedmont mountain area, consisting of three apartment blocks of mostly second homes. The adopted methodology lends itself as a guide for the feasibility study of the Superbonus and, used as a tool for policy evaluation, leads to interesting results from the point of view of both private and public convenience.

The effect on seismic demand of the soil-foundation compliance is investigated for a reinforced concrete frame building representative of Italian constructions from the 1970s. Design accounts for regulations, materials, preferred structure and foundation layouts and analysis methods of the period. Inelastic response history analysis for multiple motions at three intensities is carried out. For the compliant-base case, each foundation is replaced with a nonlinear inertial macro-element. Results suggest that the effect of interaction is minor, lower than expected from similar analysis on a new building, due to the larger degree of conservatism associated with foundation design in the considered period and the corresponding lower strength and stiffness of the superstructure.

A combination of systematic and bibliometric literature review is applied. For bibliometric analysis a citation network analysis, keyword cluster analysis, burst detection analysis and the total citation score are evaluated. So far, literature mainly deals with creation of digital building models. However, in the operational phase of a building, updating digital building models is essential in order to use the digital building models for applications like maintenance, facility management and conversion planning. In this paper approaches and methods to update digital building data are examined systematically to reflect the current state of scientific knowledge. This will identify and compare update approaches for digital building models. Nine interrelated research areas can be identified that deal with updating digital building information. Based on the body of knowledge on the topic "Updating of digital building models", research gaps and poorly represented research areas are identified. One gap in research is the use of photogrammetry to update individual buildings during their operational phase. In addition to strong research areas such as geoscience, which has produced update approaches over the years, areas like factory planning have been identified which hardly consider approaches to updating as-built data. Only the most important and largest research areas involved have been considered. A more detailed examination would be possible, but would go beyond the scope of this paper. This paper is the first to analyse updating approaches in a detailed, systematic, and bibliographic manner. The holistic view of the topic of updating approaches of digital building models helps to get an overview of existing approaches. Especially because in building operation up-to-date digital plan documents of the building are increasingly needed, this overview is necessary.

https://link.springer.com/chapter/10.1007/978-3-031-21187-4_85

The National Research Council Canada recently developed a multi-criteria and multi-level framework for seismic risk management of existing buildings in Canada. One of the key criteria in this framework is benchmark NBC edition, which refers to the applicable edition of National Building Code of Canada (NBC) in which significantly improved seismic requirements were adopted and enforced. Since post-benchmark buildings are expected to demonstrate satisfactory seismic performance, they may be exempt from structural seismic risk assessment. This paper identifies benchmark NBC editions for 17 model building types in Canada. The identification starts by tracking major seismic improvements in the United States benchmark codes and standards. These improvements are then mapped to applicable NBC editions and relevant design standards. Provincial building code editions corresponding to benchmark NBC editions are also identified. The benchmark NBC editions and corresponding provincial building code editions help building owners quickly identify and exempt post-benchmark buildings with acceptable seismic risks and thus allocate resources to the buildings with potentially unacceptable seismic risks.

Within the 2019–2021 research agreement between the Civil Protection Department (DPC) and the Network of University Laboratories for Earthquake Engineering (ReLUIS), the work package WP4 “Seismic Risk Maps—MARS” is specifically devoted to update the 2018 release of the Italian National Seismic Risk Assessment. To this end, the previously considered models of hazard, exposure and vulnerability will be critically reviewed and updated by taking advantage also from the results deriving from other WPs of the DPC-ReLUIS research project. In the present paper some of the most relevant aspects that are being introduced in the development of the new Italian risk maps have been described and shortly analysed. First, a significant upgrade of the vulnerability model implemented in the new version of the platform used for risk calculation (IRMA) is proposed, where reference to the six EMS-98 classes is made also considering regional vulnerability features. Further, empirical data from observed real damage are integrated with results from numerical simulations (mechanical approach), in particular for reinforced concrete buildings. Finally, some special construction types such as schools, churches and bridges are included in order to provide a more comprehensive view of the national risk.

The seismic vulnerability of existing RC framed buildings in seismic-prone areas requires affordable and practice-oriented solutions for their retrofitting. In this paper, the authors present a retrofitting solution for RC buildings based on the combined use of cross-laminated timber (CLT) panels and asymmetric friction connections (AFCs). The AFC connection is activated when the force level reaches the design threshold. The energy dissipation of the AFC increases the structural dissipation capacity and reduces the displacement demand. This research presents the outcomes of an experimental campaign on selected prototypes of these AFC connectors. The authors assess their dissipative capacity from cyclic load tests in four different connector arrangements and examine the contribution of aluminum shim layers. The first results highlight the significant dissipation potential of the AFC, although they also provide evidence of the notable sensitivity on the design and constructive details. The authors present a modeling approach to simulate the experimental results.

Concrete cores extracted from the same structural element may show variations in strength resulting from a lack of homogeneity and variations in the grade of compactness. This paper, while accounting for such variability, introduces a new formulation to assess both in situ and the potential characteristic strength of concrete. The first part addresses the Concrete Society report 11 on formulations and the formulation introduced by the author that considers new coefficients that take into account the addition of water to the cement mixer and the influence of excess voidage. The second part describes a case study in that the procedures were applied to an experimental campaign carried out on two series of cores. The visual means method proposed by report 11 is applied for excess voidage assessment to the first series of cores, while a computed axial tomography (CAT) scan allowing a direct estimate of the percentage of voids in different sections is applied to the cores of the second series. Results show noticeable variations in the percentage of voids within the same drilling. Moreover, the proposed formulation can estimate the actual value of both the in situ and potential characteristic strengths of concrete with a reasonable degree of approximation. Finally, a computed axial tomography (CAT) scan leads to extremely precise results, making it possible to evaluate the percentage of voids in different sections of the same core.

Most existing masonry buildings were built without following code regulations for seismic criteria. Hence, their performance compared to the demands of the current codes, for both seismic and static actions, could be very low. In engineering practice, strengthening interventions can be pursued at different levels, based on qualitative assessments of masonry structures. Firstly, the structures are evaluated through in situ inspections. Then, based on the structural system of the building a strengthening design is proposed. The design can be targeted at guaranteeing a box behavior of structures acting through macro-elements, or at strengthening the in-plane capacity of piers and spandrels. However, lower cognitive levels may drive inaccurate impressions about the capacity of structures, leading to unreliable strengthening solutions. While in some cases the confidence factor could underestimate the effects of the reinforcements, in other cases lower knowledge levels could lead to incorrect reinforcements that do not provide helpful solutions. In this paper, the issues concerning the strengthening design of masonry structures are presented and discussed with regard to an existing building. The construction is a 20th century masonry building used as a nursing home for elderly persons. The study follows a knowledge-based procedure where, after achievement of the highest knowledge level and the proposal of compatible and effective strengthening interventions, the analysis of the potential effects of achieving lower knowledge levels is discussed both in terms of vulnerability computations and in terms of strengthening effectiveness. Regarding vulnerability assessment, a lower knowledge level leads to non-conservative results, with an increase in the estimated capacity of around 80%. Critical evaluation of the different configurations for the case study makes it clear that for the considered masonry building the mortar investigation represented the most important parameter to be investigated. The proposal of strengthening interventions before assessment of this parameter may lead to ineffective improvements resulting in index values lower than 0.60. The study represents the opportunity to assess comparisons in the setting of different investigation strategies and their effect on the definition of the strengthening solutions.

H-BIM paradigms are constituted by 3-D informative contents documenting the current and past state of existing structures. Although the transversal vision and the multidisciplinary interpretation have been attributed to BIM models, in the field of monumental structures, these databases can be organized in different ways depending on the adopted protocol and classifications for the required output of the work. In this manuscript, an H-BIM approach targeted at collecting and providing useful information to execute seismic vulnerability analyses of monumental structures is presented. The BIM modeling followed a protocol based on the following steps: geometrical acquisitions, scan-to-BIM modeling, and informative data collection. The methodology has been applied to the oldest part of Palazzo Vecchio in Florence (IT), an important monumental masonry structure representing the political headquarter of the city since the Middle Ages. The parametric modeling was realized classifying the information according to structural perspectives based on the cognitive steps for the investigation of the existing structures. Finally, a seismic assessment has been realized through a simplified procedure developed for cultural heritage buildings. The outcomes of the evaluation are still part of the collected information of the H-BIM model, as an example of continuous improvement of the available contents of the database.

The need to improve the performance of Nigeria’s office buildings is due to, energy challenges, increasing population, changing user needs, and climate change. With the expansion of several Nigerian cities, existing buildings constitute a significant portion of the building stock, and improving their environmental performance could be more cost-effective than reconstruction. The use of simulation packages to assess alternative retrofitting enhancement scenarios is a straightforward approach. However, in Nigeria it is often challenging to get appropriate information to facilitate this type of evaluation; many buildings were not built to their original specifications, and when available, the records are often in a poor state due to deterioration. Studies that aimed at enhancing a building’s performance hardly stated the acquisition of the required building information. This paper investigates current practices and future possibilities of improvement measures and data capturing of existing buildings using a questionnaire survey of 133 building professionals in Benin City. The inter-relationship between energy efficiency, the environment, and building design with a high potential for meaningful retrofit to mitigate energy inefficiencies is known but not fully utilized. The collected thought on current practices signifies the need for developing a more economical and reliable methodology for data capturing and evaluation.

This work aims to provide an effective structural solution, minimizing the discomfort during the works’ execution, for how to retrofit the Day-Hospital building of the National Cancer Institute “G. Pascale Foundation” in Naples. The structural vulnerability has been preliminarily evaluated for this scope, using linear static and dynamic analyses according to code provisions. The performance index in terms of peak ground acceleration (PGA), both for the life safety (SLV) limit state and the operational (SLO) limit state, has been evaluated. A seismic assessment has been performed by finite element (FE) analyses using the SAP2000 computer program, post-processor VIS15 and plugin SPF. Two main solutions have been proposed to improve the structural performance of the existing building. The first one is based on increasing the thickness of the existing reinforced concrete (RC) cores. The second solution is characterized by strengthening the RC cores using steel plates, steel strips and angles. A comparison of the proposed interventions is provided herein from the technological and financial standpoints.

Prediction of interior room layout from observations on the exterior boundaries of a unit is sometimes needed in cases of emergencies when unit entry is denied. Seeing that 3D laser scanners are becoming smaller, lighter, and easier to carry around, this paper attempts to offer a fast method that can automatically reconstruct a room model relying merely on the 3D point cloud of the unit boundaries. The method first partitions the building floor space to generate the so-called “room seeds” from the intersections of lines that are extended from the detected wall segments. Then, the grammar approach compares different possible room configurations through a trial-and-error process to find the most possible one. The proposed method is tested on a real residential building case for validation. The proposed method may be useful in emergent cases when exact floor plans are not available. The method can be extended to other Manhattan-type buildings as long as the grammar rules are settled. Published version This work was supported by the Fundamental Research Funds for the Central Universities, funding number 22120220205 (Tongji University).

The paper describes a novel Adriseismic method for expeditious assessment of seismic risk associated with unreinforced masonry buildings. The methodology was developed for the Adriseismic project of the Interreg ADRION programme, with the aim to develop and share tools for increasing cooperation and reducing seismic risk for six participating countries within the region surrounding the Adriatic and the Ionian Seas. The method is applicable to unreinforced masonry buildings characterised by three main seismic failure mechanisms, namely masonry disintegration, out-of-plane failure, and in-plane damage/failure. Depending on the input parameters for a specific structure, the assessment yields a qualitative output that consists of the masonry quality index, the index of structural response, the level of seismic risk, and the most probable collapse mechanism. Both input and output of the method are applied in the spreadsheet form. The method has so far been applied in urban areas of participating countries in the project, including Mirandola, Italy; Kaštela, Croatia; Belgrade, Serbia. In parallel, the methodology has been validated by performing a detailed seismic assessment of more than 25 buildings, and the results have been compared with the results of the proposed expeditious method. The results show a good correlation between the two methods, for example, the structural response index obtained from the expeditious method and the capacity/demand ratio obtained from the conventional assessment method.

Energy efficiency in the building sector is a priority of the EU Commission to achieve carbon neutrality by 2050. Renovation of the existing buildings, which are currently responsible for approximately 40% of EU energy consumption and 36% of the greenhouse gas emissions can lead to significant energy savings. This paper presents the EEnvest calculation method for evaluating the financial impacts of technical risks related to energy-efficient renovation of commercial office buildings. The evaluation method aims to increase investors’ confidence and boost investments in the renovation of the existing building. Through a series of Key Performance Indicators (KPI), the technical and financial risks impact is evaluated. The results are strictly connected to building features, climatic conditions, solution sets and mitigation measures specific to the building energy efficiency project.

This article addresses seismic vulnerability assessment at an urban scale using mechanical methods, more specifically potential improvements by involving typological curves instead of standard capa...

Green retrofitting of existing buildings (GREB) represents one of the best opportunities to reduce global energy consumption and carbon emissions, as well as improve people’s health, well-being, and quality of life. It has thus received significant attention from researchers and practitioners over the years, with the proliferation of research works and publications. However, no study has attempted to comprehensively investigate the cumulative theoretical and practical value of this body of knowledge. This study aims to analyze the existing global research on GREB through the lens of a scientometric review technique and to provide pathways for future research. The scientometric mapping technique was utilized to systematically and quantitatively analyze 5,288 related bibliographic records retrieved from Scopus. Results showed that “energy efficiency” retrofitting has become the utmost research priority, while “occupant behaviour” and “indoor environmental quality” (comfort, satisfaction, air quality, etc.) are declining in importance in the current framework of GREB. Moreover, other concepts such as intelligent buildings, circular economy, and nearly Zero Energy Building (nZEB) are infusing into GREB. Based on the status-quo of practice, a holistic GREB framework involving two potential pathways – technology/approach-centred and human/physical-centred pathways – was proposed. The findings of this study not only contribute to the knowledge domain, but also act as a catalyst to spur the practice by revealing the research needs in this field.

The existing building stock is largely made up of reinforced concrete (RC) buildings, constructed between the post-World War II period and 1981, and mostly consists of buildings constructed very quickly to meet the great housing demand of this period, and buildings that do not adhere to anti-seismic and energy regulations. Today, after more than fifty years, these buildings have reached the end of their useful life cycle and their maintenance is not sustainable, presenting a series of structural, energy and architectural problems and criticalities. The myriad of possible retrofit interventions currently available for these RC structures drastically reduces when the main requirement for interventions is to avoid operational interruptions to buildings. In this case, an additive structure, operating exclusively from the outside as an exoskeleton, is typically used for achieving appropriate retrofit. In this paper, two solutions are proposed and addressed for the retrofit of an existing RC building in Italy, one through the application of a steel exoskeleton and the other through the application of an RC exoskeleton system. A set of push-over (PO) analyses is carried out to define the performance point of both the original and combined systems. The comparative results of these solutions are then discussed.

Among the buildings with strategic role for civil protection purposes part of them were built before the introduction of modern seismic codes. Aiming to guarantee their operability in case of seismic events, they have to be assessed and, hopefully, seismically upgraded. This aspect arises the necessity of reliable low computational demanding numerical models and probabilistic strategies that can be easily adopted in case of the assessment of conspicuous building stock. Part of the authors proposed and validated, in previous works, a low-demanding seismic model calibrated on ambient vibrations (SMAV) that is engaged in this paper for calculating fragility curves. On the base of dynamic and geometric properties, the SMAV model simulates the dynamic response of buildings. The herein proposed procedure adopts the SMAV model and takes into account the direction of seismic input in a probabilistic manner. The use of the ASI scale as an Intensity Measure parameter is discussed and the results are compared to those obtained with others IM scales. Although SMAV implements an equivalent linear procedure the results are compared with those obtained by more sophisticated FEM models and nonlinear dynamic analyses with a satisfactory agreement. Finally, two real case studies are presented. The fragility curves for both the case studies are calculated and discussed. The results encourage the authors to the use of fragility curves based on SMAV model. Additionally, the fragility curves can be easily implemented in seismic risk assessment procedures at urban or territorial scale and, consequently, the proposed procedure may represent a key aspect in the reduction of seismic risk and rationalization of investments for the seismic upgrading of strategic buildings.

The built environment puts the greatest pressure on the natural environment out of all human activities, so it has a fundamental obligation to be environmentally sustainable. Carbon dioxide (CO2) or carbon emissions is a significant greenhouse gas that is inevitably associated with energy use when energy is produced via the combustion of fuels. Total life cycle energy, embodied and operational energy over a building's lifetime, creates significant environmental impacts through the production of CO2. By keeping and reusing existing and historic buildings rather than discarding them and building new, the embodied energy, or the energy that is locked up, can help to mitigate future damage. These buildings already exist, which indicates that the energy consumed to build them has been applied and the carbon associated with their construction has been released. The greenest buildings are ones that are already built. They are inherently more sustainable than any new buildings even with green and zero net energy systems and can be retrofitted to become more energy efficient. To demonstrate this thesis specifically, a design project engages with an abandoned late nineteenth-century bank building in Philadelphia and transforms it into a high-performance building that is prepared for long-term use. For the immediate next use, the project creates a work environment and a new vertical expansion of residential units. The preservation field always confronts the challenge of bridging the gap between embodied energy and operational energy. In the abandoned bank, there are some aspects of this building that are near permanent and define its character, such as brick walls with masonry ornament, two bank vaults, Wissahickon Schist foundation wall, and ceiling trusses. This thesis explores new approaches to leverage the embodied energy of the permanent parts of the abandoned bank and transform it into a high-performance building. A lot of energy of the abandoned bank, the building's material, and thermal mass is still actively performing. The building's envelope, the thick masonry wall, provides a moderately good insulating effect that will temper the indoor air that also preserves its historical character both inside and outside. The embodied energy of the building's envelope is leveraged by pairing it with localized heating and cooling using a radiation and conduction system. Other approaches that increase energy performance in the existing building, include the use of phase-change material for cooling the process water, solar hot water, creating drinking water via a solar still in the skylight, and distilled water from radiant cooling surfaces. In the new construction, a thermal switch facade and double-skin facade for the residential units are proposed, along with providing flexible space with thick mobile interior wall units. Master of Architecture Global warming as a problem of the twenty-first-century increase concentrations of greenhouse gases in the atmosphere due to human actions like burning fossil fuels. The built environment puts the greatest pressure on the natural environment of all industrial parts, and it has a fundamental role to manage the environment sustainably. Total life cycle energy, embodied and operational energy over the lifetime of the buildings, creates significant environmental impacts through the production of CO2. Embodied energy is the whole amount of energy applied to extract the raw materials, manufacture, transport, install, and use the product across its life cycle. Assessments of the embodied energy of historic and existing buildings are helping to mitigate future damage to resources. These buildings already exist, which indicates that the energy consumed to build them has been applied and the carbon associated with their construction has been released. The greenest buildings are ones that are already built. They are inherently sustainable and can be retrofitted to become more energy efficient. Specifically, this design engages with an abandoned late nineteenth-century bank building in Philadelphia and transforms it into a high-performance building that is prepared for long-term use. For the immediate next use, the project creates a work environment and in a new vertical expansion, residential units. In the abandoned bank, there are some aspects of this building that are near-permanent and define its characters, such as brick walls with masonry ornament, two bank vaults, Wissahickon Schist wall, and ceiling trusses. This thesis explores the new approaches to leverage the embodied energy of the permanent parts of the abandoned bank and transform it into a high-performance building. This is achieved through various means such as providing localized heating and cooling by using a radiation and conduction system, the use of phase-change material for cooling the process water, solar hot water, creating drinking water via a solar still in the skylight and distilled water from radiant cooling surfaces. In the new construction, a thermal switch facade and double-skin facade for the residential units are proposed, along with providing flexible space with thick mobile interior wall units.

The paper presents a methodology of extraction, integration and elaboration of data from different sources using the geographic information system (GIS), to realize a georeferenced building database (GBD) useful for the seismic vulnerability assessment of existing buildings on a large scale. Three levels of GIS entities have been defined and equipped with the related information: census section (CS), urban block (UB), and individual building (IB), depending on the level of detail of dataset. Additional information about the typological and structural features has been extracted by CARTIS catalogue, to refine the data associated with each building. The data have been validated using detailed information gathered on a proper sample of buildings, which have been filed and analyzed one-by-one. The alphanumeric format of data allows for the automatic implementation of different methods available in the literature, which provide a qualitative seismic vulnerability index at different scales (whole urban district, an urban block, and a single building). Finally, the 3D representation of data and results have been elaborated, providing a tool easily searchable and constantly implementable. An application has been developed for a case study in Puglia, Italy: Bisceglie, for which 3726 IB have been assessed. The work addresses the issue of the lack of information typical of large-scale applications, exploiting all the available data sources to achieve nearly complete knowledge of existing building stock finalized to a rapid but extensive evaluation of the seismic vulnerability on an urban scale with very low computational efforts and the use of limited resources in terms of time and cost.

Latest European Union programs related to energy efficiency underline the need for retrofitting existing buildings, which are responsible for 40% of EU total energy consumption. Accounting for almost 45% of the existing building stock, the architecture of the second half of the twentieth century represents one of the main targets, becoming a vulnerable category despite its heritage value. This consciousness clarifies the urgent need of developing a new Methodology for Energy Retrofitting of Modern Architecture (MERMA), capable of integrating thermal improvement with architectural preservation. This paper aims to demonstrate the legitimacy of both issues, which share, essentially, the same concerns: supporting a sustainable development by preserving non-replaceable resources, natural or cultural as they are. The MERMA is a cohesive general methodology, based on an interdisciplinary approach. It starts from the architectural and technological inquiry, includes the energy analysis and different project proposition, and uses evaluation matrices to outline the most suitable intervention strategy. As an applicative case study, the first Olivetti office building (1963), by the architects Bernasconi, Fiocchi, and Nizzoli, is chosen. It is located in the industrial site in Ivrea, recently registered in the UNESCO World Heritage List and protected by the Italian law on heritage monument DL 42/2004. By means of the MERMA application, a reduction of 55% of the building's energy demand is assured, ensuring the fulfilment of all regulations' standards, avoiding any derogation, and preserving its heritage value. For high-quality or recognized II post-war building stock, combined energy-saving and heritage preservation is justified and proposed, instead of the sole energy retrofitting commonly applied today.

Prior to the enforcement of seismic details, older-type fully encased steel-reinforced concrete composite (SCR) columns were utilized in many buildings and bridges constructed in active seismic regions worldwide. However, there is serious lack of knowledge in the literature about the seismic behavior of older buildings’ SRC composite columns with non-seismic details. Shear strength expressions, stiffness, backbone curves, nonlinear modeling parameters, and acceptance criteria for these columns are not available. A recent testing campaign (led by the first author) provided more test data to characterize the cyclic performance of SRC columns with non-seismic details. The current study has three primary objectives (1) suggesting some test-based nonlinear modeling parameters for SRC columns; (2) developing fragility, vulnerability and resilience functions for an older-type building with non-seismic details SRC columns; and (3) assessing ASCE 41-17 SRC column modeling recommendations by comparing prototype building performance, fragility, vulnerability and resilience functions obtained using test-based backbone curves and proposed nonlinear modeling parameters with those obtained using ASCE 41-17 SRC column criteria. The methodology used to establish economic vulnerability functions accounts for uncertainties in ground motion, structural response, damages and losses by means of Monte Carlo simulation techniques. The vulnerability functions for the structural, non-structural and content components of the prototype building are established. The results of this study demonstrate that the ASCE 41-17 criteria significantly underestimates the structural capacity and resilience and overestimates the seismic fragility and vulnerability of the system; however, this may not be surprising considering the implicit conservatism included in structural engineering standards. The study shows that the ASCE 41-17 modeling criteria overestimates collapse probability by 30–50% for moderate ground shaking and by 5–15% for intense ground shaking.

The space heating of buildings represents one of the most important causes of energy consumption in Europe. The necessity to increase the share of renewable energy within the sector is hindered by the difficulty to renew and refurbish the existing building stock. In this context, heat pumps can have an important role in helping increase the renewable share of thermal energy production for the civil sector, in particular in those countries in which the electricity generation mix has large contributions from renewable energy sources. The paper presents a real-data analysis and a numerical simulation to evaluate the opportunity to substitute traditional heat generation systems (natural gas boilers) with air-source heat pumps or hybrid solutions. Three buildings located in Turin (Italy) are taken as case-study, and the hourly profiles of outdoor temperature, water supply temperature and absorbed thermal power are used to simulate four heat generation scenarios, that are compared in terms of primary energy consumption. Results show that (1) the substitution of the traditional natural gas boiler with a heat pump (with backup electric resistance) is always favorable (18% to 32% of primary energy reduction); (2) the influence of water supply temperature of each building on the overall primary energy saving is very high; (3) the adoption of a hybrid system (heat pump and natural gas boiler working alternatively) provides advantages in terms of reduced primary energy consumption only if the required supply water temperature is high. Further studies will investigate the economic aspects and will introduce comparisons with condensation natural gas boilers.

In order to mitigate Urban Heat Island Effect and global warming, both governments and scientific community are working to reduce energy consumptions. In particular, the construction sector has a high potential in reducing energy demand, by means of both active and passive solutions. The European building stock is mainly composed by existing buildings as well as historical ones, which happens to be the less energy efficient ones. Moreover, retrofit operations are more complex on historical buildings, due to strict regulations for the preservation of such historical and cultural heritage. Considering this challenge, in this work we described and in lab analyzed possible passive solutions specifically designed for historical and existing buildings. In particular, we developed innovative cool colored mortars and tested them in lab, as well as investigated cool colored mortars, cool clay tiles and cool natural gravels performance when applied as envelope and roof elements, by means of dynamic simulation.

WOS: 000422648600015, The majority of existing buildings are not safe against earthquakes in most of the developing countries. Existing building stocks should be assessed with a seismic safety assessment method before a devastating earthquake. Cheaper and quicker rapid seismic safety assessment methods can be used instead of code-based assessment methods to determine the seismic performance of existing buildings. In this study, an approach was introduced to determine the seismic performance of existing mid-rise reinforced concrete buildings with fewer parameters and process steps than code-based detailed assessment procedures. Calibration and regulation of the introduced method were conducted on the 39 collapsed buildings' projects in 1999 Kocaeli, Turkey, earthquake. Finally, 55 existing buildings located in Eskisehir, Turkey, assessed with this calibrated method and the results were compared with the results of a code-based detailed assessment method; the results showed a very good agreement of about 83%. This study shows that the proposed method can be applied for the determination of the seismic performance of existing mid-rise reinforced concrete buildings quickly and without compromising reliability., Anadolu University Scientific Research Projects Commission [0802040], This paper was supported by Anadolu University Scientific Research Projects Commission under Grant No. 0802040. The authors would like to thank the anonymous reviewers for their valuable comments and suggestions to improve the quality of the paper.

This paper presents a state-of-the-art on seismic isolation in Italy and the most important applications. Those to new strategic and public buildings are shown, as well as to new residential buildings, pointing out the very good behavior shown by the seismically isolated structures during real seismic events. Then, attention is focused on the retrofit of existing buildings, which represents the real challenge for the future. The most interesting applications to existing reinforced concrete, masonry and historic structures are shown, pointing out the specific challenges for each case. Finally, recordings obtained during the seismic sequence that struck Central Italy since August 24th, 2016, are presented and discussed. These are useful for analyzing the behavior of base isolation systems and their effectiveness under low energy earthquakes. The application of seismic isolation for new buildings is quite easy and almost always possible. It is also economically convenient, at least in medium and high seismicity areas both for reinforced concrete buildings and masonry buildings. Actually, the real challenge of seismic isolation is protection of existing buildings, especially in countries where maintenance of old structures is an important issue. It is worth reminding that, when using base isolation, the period of vibration can be chosen so as to allow input of low spectral amplitude, while the superstructure remains substantially in the elastic range. This possibility also allows for limiting or even avoiding the conventional retrofit intervention in the superstructure. In this paper the design issues for the application of base isolation in the retrofit of existing buildings are first discussed for the two cases of reinforced concrete and masonry buildings. These refer to the positioning of the isolation devices in plan and elevation and the transferring of the vertical actions during the building phases. Then the most relevant applications in Italy for existing reinforced concrete and masonry buildings are also shown. Finally, an isolation system is presented, which was set up for cultural heritage structures but is very suitable also for industrial plants.

In reinforced concrete (RC) structures, the compressive strength of concrete can play a crucial role in seismic performance and is usually difficult to estimate. Major seismic codes prescribe that concrete strength must be determined essentially from in situ and laboratory tests. Mean values obtained from such tests are the reference design values when assessing existing structures under seismic actions. The variability of concrete strength can also play an important role, generally requiring that various homogeneous domains are identified in a single structure, in each of which a specific mean value should be assumed as representative. This study analyzes the inter- and intra-variability of the concrete strength of existing buildings using a very large database made up of approximately 1600 core tests extracted from RC buildings located in the Basilicata region (Southern Italy). The analysis highlighted that concrete strength variability was dependent on the structures&rsquo, dimensions as well as on the number of storeys. Moreover, the concrete strength of cores extracted from columns was found to be, on average, lower than that from beams, thus justifying the usual practice to extract cores mainly from columns, which results in a conservative approach as well as a more feasible one. Finally, some case studies were analyzed, specifically focusing on the effects of the within-storey variability. Conservative strength values, to be used especially in the case of vertical members subjected to high axial loads, are suggested.

Public residential buildings make a large portion of the European existing stock and they quite often require deep renovation interventions. A methodology for setting priorities and targeting regeneration investments should be defined relying on the increasing use of building information modelling (BIM) tools even for managing existing buildings. The aim of this paper is to integrate the evaluation process into BIM Revit software developing a specific plug-in, a Decision support system (DSS) that will help to identify the most appropriate flats to be transformed. It is based on measuring three indicators: Usability, Fragmentation, and Constructive Modifiability. Through their weighted average it is possible to obtain a final transformability score. The proposed approach has been tested on a case study chosen within the 1st P.E.E.P. (1st public plan for council and affordable housing) that has been approved in Rome in 1964. The results demonstrate that the transformability of apartments is related mainly to the Constructive Modifiability indicator and buildings with reinforced concrete frames show higher scores. A widespread application of such a methodology on large real estate portfolio may lead stakeholders involved in housing management investments in clear choices related to maintenance of buildings.

Stainless steel offers excellent mechanical properties as well as corrosion resistance and performs better in a fire compared to carbon steel in that it retains its strength and stiffness for a longer duration. The current paper is focussed on the post-fire condition, which has received limited attention to date from the research community. The motivation for the work is to show that stainless steel elements that have been exposed to fire can be re-instated with minimal additional costs in a short time frame. The paper proceeds with a description of recent material tests into the residual properties of grade 1.4301 austenitic stainless steel, following exposure to elevated temperature. Two different types of test were conducted and these are described. Firstly, a series of tensile tests were completed on coupons taken from a loaded stainless steel beam previously examined under fire conditions. Secondly, a set of virgin coupons (i.e. which have not been previously heated or tested) were exposed to different levels of elevated temperature and cooling procedures. This is with a view to understanding the ability of structural elements made from this material to survive a fire and continue in service. The results are employed along with other data obtained from the literature to conduct a detailed study into the design considerations. The collected data includes information on the proof and ultimate strengths, ultimate strain and Young's modulus and the extent to which these are affected following the occurrence of a fire. The study is done for ferritic, austenitic and duplex stainless steel. By focusing on the effect of a fire on the mechanical properties after cooling using a statistical approach, safety factors are proposed together with a reduced reliability index based on economic and social considerations. acceptedVersion

Developing earthquake scenarios for cities in areas with a moderate seismicity is a challenge due to the limited amount of available data, which is a source of large uncertainties. This concerns both the seismic hazard, for which only recordings for small earthquakes are available and the unknown earthquake resistance of the majority of structures not designed for seismic loading. The goal of the present study is to develop coherent probabilistic mechanics-based scenarios for a mid-size building stock including a comprehensive analysis of the uncertainties. As an application, a loss assessment for the school buildings of the city of Basel is performed for different scenarios of historical significance, such as the 1356 event, and from the deaggregation of the Swiss Probabilistic Seismic Hazard Model of 2015. The hazard part of the computations (i.e. ground motion estimation) is based on this model, a regional microzonation and recordings of small earthquakes on a dense strong motion network to compute site-amplification factors. The school buildings, which are mainly unreinforced masonry or reinforced concrete shear wall buildings, have been classified according to a specifically developed taxonomy. Fragility curves have been developed using non-linear static procedures and subsequently, vulnerability curves in terms of human and financial losses are proposed. The computations have been run with the OpenQuake engine, carefully propagating all the recognized uncertainties. Scenarios before and after retrofitting measures show their impact on the earthquake safety. A sensitivity analysis shows that the largest uncertainties come from the ground motion prediction although an improvement of all parts of the model is necessary to decrease the uncertainties. Although improved data and models are still necessary to be developed, probabilistic mechanics-based models outperform the capabilities of deterministic and/or empirical models for retrieving realistic earthquake loss distributions.

A practical and fast method for thermal characterization of walls based on complex Fourier analysis is proposed to determine the thermal capacitance (defined as the product of density and specific capacity) and the thermal conductivity for a building wall using the monitored inner/outer surface temperatures and outer heat flux. This method is useful for in-situ determination of walls’ thermal properties in stochastic regimes and therefore does not require any particular constraints in boundary condition. The minimum measurement duration was analyzed by determining the relative deviation between consecutive optimal values for R and C in order to reduce as much as possible the monitoring duration for energy auditors without losing accuracy.

The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the facade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.

Nowadays about 50% of global population lives in cities, responsible for about 70% of GHG emissions and by 2030 the urbanization rate will increase to over 75%. The paper discusses new emerging concept of “Post-Carbon” City, in which the “vision” consists in the opportunity of breaking the carbon-dependent system of urban areas. It provides inspiration to re-think urban re-development patterns. In this new vision buildings and occupant behaviour role and need for new comprehensive planning tools are investigated. The paper deals with a project that is undergoing study and represents a picture of the current situation related to “Post-Carbon” City topic.

This paper describes fundamental aspects of building facade retrofit practice using field-based research. A major challenge of sustainability is to require buildings to be resilient assets in a life cycle perspective. Building retrofit, a growing research area during the last decade, finds its fundament on the urgency of decreasing the harmful effect of buildings in the environment, and improving them as healthier places for occupants. For these reasons, facade retrofit is rapidly expanding as a research area. Historically, facades have been modified for numerous reasons, such as fixing failures or accommodating aesthetic trends. Currently, the central role of the facade in building energy efficiency is driving an assessment of the potential impact of widespread facade retrofit as a means to improve building sector energy performance. Two online surveys were performed between 2013 and 2014 among building facade professionals. The first survey was intended to identify predominant broad stroke facade retrofit practices. The second survey drilled down to a deeper level of design and construction, as well as motivations and goals. Respondents were highly linked to facade consultancies, facade contractors, and material suppliers. The results included a high percentage of buildings located in the United States. The information is presented in this paper using descriptive statistics to represent facade retrofit demographics, motivations and scopes, and techniques. This aim is to contribute qualified survey data for a better understanding of the fundamental aspects of current facade retrofits practices.

Energy Performance Certificates (EPCs) are issued for buildings constructed, sold or leased across the EU. Using a generalizable methodology this work exploits Ireland's EPC national dwelling stock database to determine the thermal refurbishment status of Ireland's housing stock. It is estimated in 2014 that; i) 58% of walls were insulated at a mean overall heat loss coefficient or U-value of 0.66 W/m2K, ii) 67% of roofs were insulated at a mean U-value 0.37 W/m2K, iii) 97% of windows were double-glazed, and iv) 53% of floors were insulated to a mean U-value of 0.59 W/m2K. The (i) extent of thermal refurbishments and (ii) high degree of energy-efficiency improvements in Ireland contribute significantly to household energy usage per square metre being 9% below the EU 27 average in 2010, and the average energy efficiency of Irish housing having improved by over 34% between 1995 and 2011 (2.5% per annum). The distinction between the thermal efficiency of pre-thermal building regulation and post-thermal building regulation dwellings, whilst still valid, is lessening. A strong association between dwelling age and energy efficiency often-made is diminishing as retrofits continue to be carried out. The long-held view that the majority of Irish dwellings are thermally sub-standard is no longer valid.

There is an increasing demand for the decarbonization of existing buildings. The development of standardized calculation methods has simplified calculation processes and enabled wider engagement with the topic. As the industry advances, optimization and accounting for regional differences will increase in importance. This paper reviews the key drivers in the field, both locally and internationally, and proposes a performance-based evaluation method specific to local construction in Egypt. The aim of the method is to assist in the renovation of existing buildings by guiding the decision-making process through the proposed evaluation framework. A local case study of an existing multi-story apartment building was used to create a baseline for typical local multi-story residential buildings and demonstrated the effectiveness of the proposed evaluation method. This framework provides the owners of buildings with a decision-making process by which carbon impacts associated with future renovations and operations of existing buildings can be minimized.

The current building culture requires a more careful and sensitive attention to environmental problems and the necessity to reduce the building energy requirement using sustainable products and solutions (eg. re-use of agricultural by-products). This research concerns the study of insulating existing buildings with straw (internal and external insulation) realized in Europe and in New Mexico. The case studies are analyzed with a technological point of view through the dissection of the insulation build-up to understand the construction phases during its insulation. The analysis of each case regards three building parts: the upper enclosure, the vertical enclosure and the attachment between the vertical enclosure and the ground. The application of this working method allows the analysis and understanding of how different elements are connected to each other, the possible finishing solutions and the relationship between the straw insulation and the existing building. This research analyzes different examples in order to develop a possible improved solution through the critical analysis of different construction methods used in the buildings. It is possible to achieve a classification methods of straw insulation found in the study cases and analyze every single part in the insulation system.

Governments and private investors are increasingly becoming aware of the marketing power and the importance of seismic safety of old cores of their cities. Hereby the interest in preserving the original look and often even the original, but improved construction of the buildings becomes imperative and a demanding task for engineers and project managers. The main goal of project management is controlling the outcome of a project through control of elements like quality of the final product, costs and time, whereas practice shows that these types of projects very often overrun cost and time limits. Therefore these are the main research questions: Can construction projects on strengthening and preserving existing buildings be successfully governed with existing risk management tools? If not, how can we improve the existing risk management tools? In this paper development of a new risk breakdown structure for construction projects on existing and historical buildings is presented. The risk breakdown structure is developed based on previous project experiences and in collaboration with a series of experts.

Mini-sized steel pipe pile technology is more used to foundation reinforcement, underpinning and isolation under the condition of construction site or space is limited. This paper discusses the mechanism and construction technology of mini-sized steel pipe grouting pile foundation underpinning technology. This paper shows how to effectively solve the problems of existing buildings foundation reinforcement construction through the actual engineering examples. This paper also analysis of the feasibility and validity of the mini-sized steel pipe grouting pile foundation underpinning technology, the research results can provide a practical and feasible construction scheme for similar engineering.

This paper presents a simplified model for describing the response of a longitudinal bar embedded in concrete, taking into account the bond-slip phenomenon. The model is developed by assuming a linear bond-slip field along the bar anchorage length and provides a simplified stress-strain relationship to assign to the longitudinal reinforcement. The analytical approach adopted makes the proposed model very convenient from a computational standpoint because, unlike many other refined models, it does not require a multilevel iterative process. Moreover, the assumptions made are particularly appropriate for modeling bond-slip of smooth bars generally used in older reinforced concrete buildings. The implementation strategy of the proposed bond-slip model in general-purpose nonlinear structural analysis software and comparisons with experimental results are discussed in a companion paper.

A large number of research studies have been recently devoted to the modelling and analysis of infilled RC framed buildings under seismic actions, and the significant role that the infill plays in the overall structural performance is by now a well acknowledged result. In particular, the extension of N2 method to infilled frame allows the appraisal of this contribution within the framework of a non linear static analysis. The present paper reports the results of the non linear static assessment performed for two RC existing buildings located in a high seismic hazard area. Both building are characterized by regularity in plan and elevation, but while the first one is a low rise construction, the second one is relatively tall (7-storey). Thence, there is the possibility of considering two different and interesting situations. For the two case studies, moreover, a complete investigation protocol was previously carried out, providing a detailed experimental information about the materials (concrete, steel reinforcements, masonry infill). Numerical analyses were performed by using spatial models, both for the bare frames and for the infilled frames, in order to appraise the variation of the structural capacity because of the interaction of the infills with the RC elements.

[ES] La amplitud y diversidad de situaciones que se pueden plantear en estos trabajos de peritación, hacen que cualquier norma para regular su contenido omita casos que deben ser resueltos por el perito según su "leal saber y entender". Por la transcendencia y responsabilidad que se puede derivar de ellos, vamos a analizar algunos aspectos vinculados a su repercusión desde el punto de vista legal y profesional., [EN] The breadth and diversity of different situations that may arise in expert's surveys make any rules to regulate its content skip cases that must be solved by the surveyor/expert as its "best knowledge." On the importance and responsibility that can be derived from them, we will analyse some of the aspects related to its implications, in terms of legal and professional point of view.

Operational activities of gas pipelines are associated with potential hazards and risks that can potentially lead to pipeline failure, including failure of the gas distribution pipeline in existing buildings. Unfortunately, few studies on risk analysis of the gas distribution pipeline in existing buildings have been published. Therefore, this study was conducted to provide a reference for analyzing the risk of pipeline leakage caused by small-scale leakage, large-scale gas release, and gas pipeline rupture in existing buildings in Indonesia not designed for gas installation. The study was performed using the event tree analysis method. The methodology of this study was initiated by identifying the scenario of the case of small-scale leakage, large-scale gas release, or gas pipeline rupture. Then, pivotal events were identified, an event tree diagram was constructed, the event failure of each pivotal event was determined, and the probability value of the outcome risk was calculated. The risk was evaluated in terms of fire, casualties, and gas released. The results of this study showed the highest risk in each scenario which can result in fire, severe casualties, and light poisoning. The highest risk in the small-scale leak scenario had a probability value of 1.5 &times, 10&minus, 3. In the large-scale gas release scenario, the highest risk had a probability value to incur a fireball, severe casualties, and light gas poisoning of 6.0 &times, 4. In the gas pipeline rupture scenario, the highest risk had a probability value of fireball, severe casualties, and light poisoning of 7.0 &times, 4. The probability value of each risk was reduced by the installation of a gas detector and water sprinkler as a barrier.