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Premature shear failure in reinforced concrete (RC) beam–column joints (BCJs) or at the top of columns can significantly compromise a building's seismic response, leading to major damage or global collapse, as observed in the aftermath of recent seismic events. Local strengthening solutions based on the employment of fiber-reinforced polymers (FRPs) are effective at increasing shear strength and preventing the failure of BCJs, and are also quick and easy to apply. This has led to their increased use in recent postearthquake reconstruction processes. However, large-scale plans to mitigate seismic risk require strengthening solutions that produce a minimum level of disruption and do not prevent the use of buildings. This can be achieved only by conducting work from a structure's exterior. This paper, therefore, proposes a novel FRP strengthening layout for exterior RC BCJs that combines the use of quadriaxial fabric and mechanical FRP spike anchors. In order to validate the proposed solution and quantify the effects of the number of layers and anchors, four full-scale BCJs are tested under a constant axial load and reversed cyclic displacement. The results are presented and discussed in relation to: global subassembly and local joint-panel response, energy dissipation, and the strain demand on the FRP fibers. A comparison with current available design formulations for anchored-FRP fabrics is made to produce preliminary design criteria. [ABSTRACT FROM AUTHOR]

AbstractThe peak roof drift ratio is one of the most important engineering parameters to describe the expected seismic damage in a building. A predictive model of the drift ratio was developed using a machine learning approach (Gaussian process regression model) on a dataset of approximately 11,800 records from 34 monitored buildings in Japan. Four predictors for ground motion and three predictors for building vulnerability are used in the machine-learning modelling. The residual analysis shows a reduction of 50% compared to the state of the art. The Gaussian process regression model is applied in a second analysis on an original dataset of approximately 4,500 records for 127 monitored buildings in Italy. A satisfactory comparison emerges by comparing the drift ratio prediction map with the observed damage pattern produced by satellite imagery for a test site in central Italy after the 2009 earthquake. The drift ratio map plays an important role in the simulation of an earthquake scenario at regional scale, which is needed by Civil Protection for emergency planning and management activities.

As one of the most earthquake-prone regions in the world, China faces extremely serious earthquake threats, especially for those heavily populated urban areas located near large fault zones. To improve the ability to prevent and minimize earthquake disaster risks, and to reduce earthquake disaster losses, China is currently building a nationwide earthquake early warning system (EEWS) with the largest seismic network in the world. In this paper, we present the newest progress of this project through describing the overall architecture of the national EEWS and evaluating the system performance during the 2022 Lushan M6.1 earthquake. The accuracy of the source characterization for the Lushan earthquake is discussed by comparing the continually estimated location and magnitude with the catalogs obtained from the China Earthquake Networks Center. For this earthquake, the EEWS generated a total of five alerts, and an initial alert was created 5.7 s after its occurrence, with excellent epicentral location and origin time estimation. The final alert was issued 16.5 s after origin time with a magnitude estimate of M6.1, the same as the catalog value. However, from the point view of alerting performance, the radius of the real blind zone without warning time was about 30 km and much larger than the theoretical result, mainly caused by the releasing system not considering the epicenter distance of each terminal when issuing the alerts. Although the earthquake exposed some limitations that need to be addressed in future upgrades, the results showed that most aspects of the EEWS presented a robust performance, with continuous, reliable event detections and early-warning information releasing. [ABSTRACT FROM AUTHOR]

This paper contains an investigation on the potential decrease of seismic vulnerability related to building replacements for the cities of Sion and Martigny in Switzerland. Those two cities were identified for the present research based on the accuracy of the corresponding available information. Seismic assessment at urban scale was recently achieved for both cities and new buildings are systematically indexed according to the construction regulation of the canton of Wallis (Valais). Sion and Martigny belong to the largest cities of the canton of Wallis and this region is characterized by the highest seismicity within Switzerland. The investigation focuses on a 4-year period between 2016 and 2019. Cases for which an existing building is demolished and replaced by a new one were identified and checked. Those cases do not represent general practice. The majority of new buildings are built on free land. Consequently, the building replacement rate is too low to lead to a significant decrease of the seismic vulnerability at urban scale. In addition to the systematic appropriate seismic design of new buildings, retrofitting of existing buildings therefore remains the adequate strategy for seismic vulnerability mitigation. In case of replacement, low-rise buildings are generally replaced by mid-rise buildings. Moreover, unreinforced masonry buildings are usually replaced by reinforced concrete shear-wall buildings. This slightly impacts the building stock distributions but the seismic vulnerability is not significantly changed, since the demolished buildings are not the most vulnerable ones. Nevertheless, few obvious isolated vulnerability decreases occurred with respect to the demolition of soft-story buildings for instance. By contrast, seismic vulnerability may also be increased in the case where a new building is built against an existing one with a different story level and without an adequate seismic separation joint.

A new experimental apparatus for performing impact tests is presented, to analyse the wave propagation phenomenon in pure sand and in composite sand-polyurethane specimens, with the final aim to explore the seismic mitigation given by a polyurethane inserted into a real soil under existing structures. Polyurethane layers at three different thicknesses are considered. Experimental results show that composite specimens provide acceleration reductions increasing with the increase of polyurethane thickness. Result interpretation in the light of the elastic wave propagation theory is presented, pointing out the experimental set-up limitations, mainly due to the lack of sufficient specimen confinement. [ABSTRACT FROM AUTHOR]

The fundamental objective of earthquake engineering is to protect lives and livelihoods through the reduction of seismic risk. Directly or indirectly, this generally requires quantification of the risk, for which quantification of the seismic hazard is required as a basic input. Over the last several decades, the practice of seismic hazard analysis has evolved enormously, firstly with the introduction of a rational framework for handling the apparent randomness in earthquake processes, which also enabled risk assessments to consider both the severity and likelihood of earthquake effects. The next major evolutionary step was the identification of epistemic uncertainties related to incomplete knowledge, and the formulation of frameworks for both their quantification and their incorporation into hazard assessments. Despite these advances in the practice of seismic hazard analysis, it is not uncommon for the acceptance of seismic hazard estimates to be hindered by invalid comparisons, resistance to new information that challenges prevailing views, and attachment to previous estimates of the hazard. The challenge of achieving impartial acceptance of seismic hazard and risk estimates becomes even more acute in the case of earthquakes attributed to human activities. A more rational evaluation of seismic hazard and risk due to induced earthquakes may be facilitated by adopting, with appropriate adaptations, the advances in risk quantification and risk mitigation developed for natural seismicity. While such practices may provide an impartial starting point for decision making regarding risk mitigation measures, the most promising avenue to achieve broad societal acceptance of the risks associated with induced earthquakes is through effective regulation, which needs to be transparent, independent, and informed by risk considerations based on both sound seismological science and reliable earthquake engineering. [ABSTRACT FROM AUTHOR]

In recent years, the preservation strategies of cultural heritage have become an element of considerable importance. Unfortunately, research has often been conducted in an excessively mono-sectoral or disaggregated manner. Moreover, there is a significant number of reinforce concrete (RC) buildings and engineering works that are of historical interest and play a key role during the earthquakes. An urban center, its historical structures and infrastructures or single buildings, if well managed, preserved, protected, recovered and enhanced can represent an excellent source of income and induce a considerable economic development in the neighboring areas. On the other hand, a lack of value appreciation and/or incorrect management represent a significant economic loss in the long-term, but an immediate loss after earthquakes. In this work, the historical and cultural value of these RC structures and infrastructures is discussed and the main critical issues are identified, outlining the fundamental requirements for conservation. [ABSTRACT FROM AUTHOR]

We analyze the performance of a prototype earthquake early warning system deployed at the National Seismological Network of Costa Rica in collaboration with the Swiss Seismological Service by presenting the real-time performance during six earthquakes (Mw 5.1-6.4) that took place during 2018 and 2019. We observe that, despite only limited efforts to optimize the existing network of 158 stations, for EEW purposes, the network density allows fast determination of source parameters using both the Virtual Seismologist and the Finite Fault Rupture Detector algorithms. Shallow earthquakes on or near-shore are routinely identified within 11–20 s of their occurrence. The warning times for the capital city of San Jose are of 43 s for epicenters located at 220 km, like for the Mw 6.4 Armuelles earthquake. On the other hand, during the time analyzed, the EEW system did not provide positive warning times for earthquakes at distances less than 40 km from San Jose. Even though large (Mw > 7) distant historical earthquakes have not caused heavy damage in San Jose, there is potential for developing an EEW system for Costa Rica, especially for the purposes of rapid earthquake notifications, disaster response management, and seismic risk mitigation.

This paper deals with the seismic vulnerability assessment of dwellings in the historic centre of Cusco (Peru), one of the most important UNESCO sites in the world. This activity is framed within a cooperation agreement between the University of Chieti-Pescara (Italy), the Andina University del Cusco (Peru), the Pontifical Catholic University of Peru and the Cusco Municipality (Peru) whose main focus is the seismic risk evaluation of the whole historic centre. Following a discussion on the development of the historic centre and the main construction typologies, the paper presents the main outcomes of an extensive in-situ survey for collecting structural information on the buildings. Statistics regarding the data are given and shown in a GIS environment. The collected data are then used to implement an empirical model for the seismic vulnerability assessment of a significant part of the historic centre. The model is derived using a methodology already proposed by the authors for Italian historic centres. The original model is adapted to the peculiarities of the structural typologies found in Cusco. Finally, fragility curves are derived and used in order to assess the potential seismic vulnerability reduction achieved by applying proper retrofitting interventions at the large scale. [ABSTRACT FROM AUTHOR]

Aswan area is characterized by complex tectonic and structural settings. It has very important strategic and archeological sites. The high density of population in this moderate active seismic area makes it important to study in detail its seismicity, seismotectonics, focal mechanism, stress field, types, and orientations of faults. A catalogue of 2685 earthquakes recorded by the Egyptian national seismological network from 2010 to 2019 was analyzed and revealed different seismic b-values which reflect that the Aswan area is subjected to different stresses. These events were relocated using the relative relocation technique to preciously determine the hypocenter locations. The relocated events refined the image of its seismicity and subsurface faults. The focal mechanisms of some relocated events were studied using the first polarities of P-waves and showed that the Kalabsha fault is affected by a right lateral strike-slip movement with normal dip slip component, while Khour El-Ramla, Kurkur, Abu Dirwa, and Gazelle faults are affected by a left lateral strike-slip movement with normal dip slip component. In addition, the stress field was studied from the inversion of focal mechanisms to define the principal fault plane parameters, principal stress axes, frictions, and shape ratios in Aswan area. It showed that the eastern part of Kalabsha fault is the most active segment in Aswan area. The results of this study can be a very useful basis in seismic hazard assessment and seismic risk mitigation. [ABSTRACT FROM AUTHOR]

The current seismic prevention strategy is based on a unitary approach aimed at a risk mitigation, also at territorial level. The Italian guidelines for the assessment and mitigation of seismic risk of cultural heritage provides indications for the seismic analysis of protected cultural heritage, with the aim of specifying a path of knowledge, assessing the level of safety and planning possible improvements. The Italian building heritage is very vast and heterogeneous and was devastated by earthquakes due to its high vulnerability; therefore, the seismic risk mitigation also requires the availability of simple and handy analysis tools. The aim of this paper is the illustration of an easy, although approximate, procedure for the evaluation of the seismic safety index and the optimization of strengthening interventions. The procedure is applied to buildings located in the province of Caserta. The analyses are performed with reference to two types of buildings that are particularly recurrent and representative of the building heritage of this area and placed in areas with different seismic hazard.

The notion of seismic risk is employed to describe the effects of earthquakes on social, economic and environmental aspects over a certain period of time and can be defined as the interaction of three parameters: seismic hazard, exposure time and structure vulnerability. A high seismic risk does not involve a high seismic hazard and vice versa. Disaster risk management is quantified by the application of appropriate policies and strategies necessary to prevent and reduce the risk, manage residual risk, thereby enhancing the resilience of the system. There are two strategic ways to reduce seismic risk: the improvement of emergency response and the adequate design of structures. Prevention is the most cost-effective solution and can play even the role of a driver for economic growth, and it is granted more attention in the disaster management cycle. Performance based seismic design involves the development of safety criteria in which the hazard is determined probabilistically as a function of the potential consequences of failure. Even if earthquakes cannot be accurately predicted, the disastrous consequences produced by human loss, economic and social damage can be minimized. In this paper, models of seismic risk mitigation programs for Turkey, Greece and Romania are presented.

Urban renewal projects typically involve redevelopments of under-utilized old buildings and revitalizing precious land resources. Due to architectural and social-economic reasons, historical façades are sometimes retained, and new constructions are built behind them. This allows the historical façade, typically the street elevation, to remain while new real estate can be redeveloped. In the profession of architecture, this is called façadism. In many cases, these historical façades are constructed with unreinforced masonry (URM). When these facades are retained and the remaining of the building is demolished, they become free-standing walls. Temporary supports are required throughout construction works and the retained façades must be designed to prevent excessive movements, allowed for differential movements and to resist wind forces. These historical façades were made of brittle materials and were constructed many decades ago before modern design standards and materials are available. They possess very little ductility and become vulnerable when subjected to ground shaking. The present study suggests a structural system that attempts to mitigate seismic risk of façadism constructions effectively. The structural system divides the new construction, which can be a reinforced concrete structure or a steel frame structure, into two separate frames. A seismic gap is introduced between them and produces two systems of different vibrational characteristics. Supplemental energy dissipating devices such as viscous fluid or friction dampers are placed in-between adjacent floors. The proposed structural system utilizes the different vibrational responses of two frames to facilitate energy dissipation in dampers. In this article, governing equations are presented, followed by numerical simulations using historical earthquake acceleration histories. Results demonstrate that the suggested structural system is an effective methodology to suppress seismic responses of the façade and the new construction. It is concluded that damage on the retained façades can be prevented, and at the same time seismic responses to the newly constructed structure can be controlled.

Seismic risk mitigation levels for an existing building are a balance between the reduction of risk and the cost of rehabilitation. Evidently, the more that is paid the more risk is reduced; however, due to limited public budgets a practical approach is needed to manage the risk reduction program when a portfolio of buildings is concerned. Basically, decision makers face a challenge when there are a large number of vulnerable buildings and there is no plan for how to allocate the appointed budget. This study develops a technological platform that implements a decision-making procedure to establish how to optimally distribute the budget in order to achieve the maximum possible portfolio risk reduction. Decisions are made based on various presumed intervention strategies dependent on building's level of risk. The technological platform provides an interactive, user-friendly tool, available online, that supports stakeholders and decision makers in understanding what the best economic resource allocation will be after selecting the available budget for a specific portfolio of buildings. In addition, the ease of use enables the user to analyze the extent of risk reduction achievable for different budget levels. Therefore, the web platform represents a powerful tool to accomplish two challenging tasks, namely optimal budget selection and optimal budget allocation to gain territorial seismic risk mitigation. [ABSTRACT FROM AUTHOR]

Every year, natural hazards affect millions of people around the world, causing significant economic and life losses. The rapid progress of technology and advances in understanding of the highly complex physical phenomena related to various natural hazards have promoted the development of new disaster-mitigation tools, such as earthquake early warning (EEW) systems. However, there is a general lack of integration between the multi- and cross-disciplinary elements of EEW, limiting its effectiveness and applications for end users. This paper reviews the current state-of-the-art in EEW, exploring both the technical components (i.e., seismological and engineering) as well as the socio-organizational components (i.e., social science, policy, and management) of EEW systems. This includes a discussion of specific evidence from case studies of Italy, United States’ West Coast, Japan, and Mexico, where EEW systems have reached varying levels of maturity. Our aim is to highlight necessary improvements for increasing the effectiveness of the technical aspects of EEW in terms of their implications on operational, political/legal, social, behavioral, and organizational drivers. Our analysis suggests open areas for research, associated with: 1) the information that needs to be included in EEW alerts to implement successful mitigation actions at both individual and organizational levels; 2) the need for response training to the community by official bodies, such as civil protection; 3) existing gaps in the attribution of accountability and development of liability policies involving EEW implementation; 4) the potential for EEW to increase seismic resilience of critical infrastructure and lifelines; 5) the need for strong organizational links with first responders and official EEW bodies; and 6) the lack of engineering-related (i.e., risk and resilience) metrics currently used to support decision making related to the triggering of alerts by various end users.

In recent years, the preservation strategies of cultural heritage have become an element of considerable importance. Unfortunately, research has often been conducted in an excessively mono-sectoral or disaggregated manner. Moreover, there is a significant number of reinforce concrete (RC) buildings and engineering works that are of historical interest and play a key role during the earthquakes. An urban center, its historical structures and infrastructures or single buildings, if well managed, preserved, protected, recovered and enhanced can represent an excellent source of income and induce a considerable economic development in the neighboring areas. On the other hand, a lack of value appreciation and/or incorrect management represent a significant economic loss in the long-term, but an immediate loss after earthquakes. In this work, the historical and cultural value of these RC structures and infrastructures is discussed and the main critical issues are identified, outlining the fundamental requirements for conservation.

Identifying optimal seismic mitigation strategies (i.e., groups of bridges to retrofit) for effective risk mitigation of transportation networks entails significant computational challenges due to the large number of bridge combinations and the seismic risk evaluation of network for each mitigation strategy, especially for large-scale network. An efficient sample-based approach is proposed to address these challenges. It uses only one set of simulations of the network model to generate samples to estimate a probabilistic sensitivity measure that provides importance ranking of bridges associated with the seismic risk. Three selection approaches using the importance ranking are proposed to guide an effective search of mitigation strategies. The same set of simulations are also used to efficiently evaluate the updated seismic risk for any given mitigation strategy. The efficiency and effectiveness of the proposed approach are validated through its application to seismic risk mitigation of the transportation network of Los Angeles and Orange counties. [ABSTRACT FROM AUTHOR]

Masonry churches represent the major part of the Italian architectural heritage. Recent earthquakes stressed the high vulnerability of these constructions, provoking heavy structural damage and valuable losses. Different approaches have been developed to assess seismic vulnerability of churches. In particular, the complexity related to more detailed models has induced to define simplified methods, which can be used at territorial scale for a preliminary assessment of structural capabilities of homogeneous assets aiming at providing possible post-earthquake damage scenarios and suggesting general interventions strategies. Therefore, the vulnerability assessment of churches is carried out by subdividing the buildings into separate macro-elements, accounting for different possible collapse mechanisms. In this article, a simplified procedure (M.I.T. 2011) has been applied with reference to churches located in Caserta District, particularly those of the Alife-Caiazzo Diocese, by using the MaChro form compilation, previously developed by the authors. The aim of the study is the application of the above procedure in order to verify the possibility to suggest suitable strategies of intervention for structural retrofitting and seismic risk reduction of the churches located in the area under investigation. [ABSTRACT FROM AUTHOR]

An experimental investigation was conducted to assess the performance of a new buckling-restrained brace (BRB) system for retrofitting seismically deficient reinforced concrete frames. The BRB consists of a ductile inner steel core bar designed to yield in tension and compression without buckling while controlling the response to seismic forces. The core bar is contained within a tubular steel section, which in turn is housed in a larger tubular steel section infilled with mortar, providing lateral restraint against buckling. Self-consolidating mortar is used as filler material between the two tubular sections to increase the buckling resistance. The inner core bar is connected to innovative end units that allow extension and contraction during tension-compression cycles while providing lateral restraint against buckling. The new BRB system has been verified experimentally using two large-scale reinforced concrete frames, one of which was tested as a reference nonretrofitted frame and then repaired and retested three more times after BRB retrofits, while the other was retrofitted and tested, forming the fourth retrofitted frame test. Tests demonstrated substantial increases in the lateral load and energy dissipation capacities of retrofitted frames with satisfactory drift control. Three different types of steel bars with different strength and elongation characteristics were considered. Among the three, stainless steel provided the best strength, stiffness, and ductility enhancements. [ABSTRACT FROM AUTHOR]

The main goal of an Earthquake Early Warning System (EEWS) is to alert before the arrival of damaging waves using the first seismic arrival as a proxy, thus becoming an important operational tool for real-time seismic risk management on a short timescale. EEWSs are based on the use of scaling relations between parameters measured on the initial portion of the seismic signal after the arrival of the first wave. To explore the plausibility of EEWSs around the Eastern Gulf of Corinth and Western Attica, amplitude and frequency-based parameters, such as peak displacement (Pd), the integral of squared velocity (IV 2) and the characteristic period (τc), were analyzed. All parameters were estimated directly from the initial 3 s, 4 s, and 5 s signal windows (tw) after the P arrival. While further study is required on the behavior of the proxy quantities, we propose that the IV 2 parameter and the peak amplitudes of the first seconds of the P waves present significant stability and introduce the possibility of a future on-site EEWS for areas affected by earthquakes located in the Eastern Gulf of Corinth and Western Attica. Parameters related to regional-based EEWS need to be further evaluated.

Seismic risk mitigation levels for an existing building are a balance between the reduction of risk and the cost of rehabilitation. Evidently, the more that is paid the more risk is reduced; however, due to limited public budgets a practical approach is needed to manage the risk reduction program when a portfolio of buildings is concerned. Basically, decision makers face a challenge when there are a large number of vulnerable buildings and there is no plan for how to allocate the appointed budget. This study develops a technological platform that implements a decision-making procedure to establish how to optimally distribute the budget in order to achieve the maximum possible portfolio risk reduction. Decisions are made based on various presumed intervention strategies dependent on building’s level of risk. The technological platform provides an interactive, user-friendly tool, available online, that supports stakeholders and decision makers in understanding what the best economic resource allocation will be after selecting the available budget for a specific portfolio of buildings. In addition, the ease of use enables the user to analyze the extent of risk reduction achievable for different budget levels. Therefore, the web platform represents a powerful tool to accomplish two challenging tasks, namely optimal budget selection and optimal budget allocation to gain territorial seismic risk mitigation.

The current seismic prevention strategy is based on a unitary approach aimed at a risk mitigation, also at territorial level. The Italian guidelines for the assessment and mitigation of seismic risk of cultural heritage provides indications for the seismic analysis of protected cultural heritage, with the aim of specifying a path of knowledge, assessing the level of safety and planning possible improvements. The Italian building heritage is very vast and heterogeneous and was devastated by earthquakes due to its high vulnerability; therefore, the seismic risk mitigation also requires the availability of simple and handy analysis tools. The aim of this paper is the illustration of an easy, although approximate, procedure for the evaluation of the seismic safety index and the optimization of strengthening interventions. The procedure is applied to buildings located in the province of Caserta. The analyses are performed with reference to two types of buildings that are particularly recurrent and representative of the building heritage of this area and placed in areas with different seismic hazard. [ABSTRACT FROM AUTHOR]

The resilience of communities is given by the ideal convolution of the resilience of all their single parts. Strategic buildings require high levels of performance during and after a seismic sequence. Consequently, the seismic retrofitting of old strategic buildings is a central issue in prevention and mitigation strategies. The core of the study is a resilience approach to the seismic retrofitting of existing strategic buildings. Different performance levels are considered and four different retrofitting techniques are compared according to their fragility, and their post-earthquake cost and time recovery analyses. Lastly, the retrofitting techniques are compared based on the considered resilience index, which in turn is related to the estimated reduction of the seismic losses owing to the different retrofitting techniques, but especially to the effectiveness of the intervention based on the relevant cost and recovery times. In other words, these aspects take into account the key role of a building’s characteristics, and its public and strategic role during and after an earthquake. The intervention is selected not only (as is currently done) to reduce its construction times and costs, but to limit the service interruption after earthquakes. The results of this study could be operatively used as support tools in the seismic retrofitting of strategic buildings, either individually or on a large territorial scale.

The increasing scale of losses from earthquake disasters has reinforced the need for property owners to become proactive in seismic risk reduction programs. However, despite advancement in seismic design methods and legislative frameworks, building owners are found unwilling or lack motivation to adopt adequate mitigation measures that will reduce their vulnerability to earthquake disasters. Various theories and empirical findings have been used to explain the adoption of protective behaviours including seismic mitigation decisions, but their application has been inadequate to enhance building owners’ protective decisions. A holistic framework that incorporates the motivational orientations of decision-making, coupled with the social, cultural, economic, regulatory, institutional and political realms of earthquake risk mitigation to enhance building owners’ decisions to voluntarily implement adequate mitigation measures, is proposed. This framework attempts to address any multi-disciplinary barriers that exist in earthquake disaster management, by ensuring that stakeholders involved in seismic mitigation decisions work together to foster seismic rehabilitation of EPBs, as well as illuminate strategies that will initiate, promote and sustain the adoption of long-term earthquake mitigation. .

.The notion of seismic risk is employed to describe the effects of earthquakes on social, economic and environmental aspects over a certain period of time and can be defined as the interaction of three parameters: seismic hazard, exposure time and structure vulnerability. A high seismic risk does not involve a high seismic hazard and vice versa. Disaster risk management is quantified by the application of appropriate policies and strategies necessary to prevent and reduce the risk, manage residual risk, thereby enhancing the resilience of the system. There are two strategic ways to reduce seismic risk: the improvement of emergency response and the adequate design of structures. Prevention is the most cost-effective solution and can play even the role of a driver for economic growth, and it is granted more attention in the disaster management cycle. Performance based seismic design involves the development of safety criteria in which the hazard is determined probabilistically as a function of the potential consequences of failure. Even if earthquakes cannot be accurately predicted, the disastrous consequences produced by human loss, economic and social damage can be minimized. In this paper, models of seismic risk mitigation programs for Turkey, Greece and Romania are presented. [ABSTRACT FROM AUTHOR]

In this article, a predictive model for the seismic vulnerability assessment of old Italian historic centers is presented through its direct application to a meaningful case study, the historic center of Scanno, in Abruzzi, Italy. The proposed method is calibrated on the basis of the observations carried out on similar historic centers hit by the 2009 L’Aquila earthquake and is applied in order to provide likely damage scenarios by means of fragility curves. The method is based on the evaluation of a limited number of structural and typological parameters that can be obtained by simple and rapid inspections on buildings. In addition, it is conceived in order to provide useful information on the most effective anti-seismic strategies to be implemented on urban scale for pursuing a global mitigation of the seismic risk and for the application of suitable risk reduction policies. The final aim of the article is to give an applicative vision of the method, by providing instructions on how to judge the features of the buildings that are influential on their seismic behavior, as well as by showing the potentiality of the method itself in providing likely damage scenarios, also with the support of GIS-based representations. [ABSTRACT FROM AUTHOR]

Oamaru, Winton, and Invercargill feature some of New Zealand’s most intact heritage precincts that are confronted by ongoing threats of seismic activity. The 2010/2011 Canterbury earthquake sequence and Canterbury Earthquakes Royal Commission of 2012, identified a nationwide trend through the proportion of deaths that occurred in public places as a result of the prevalent historic unreinforced masonry (URM) building stock. The reported study was undertaken to address urban safety and seismic risk mitigation through the lens of heritage conservation. The range of classically designed public buildings and industrial warehouses in the South Island of New Zealand were often produced by singular architectural practices, using locally sourced materials and construction techniques. It is vital to incorporate an examination of unique architectural qualities within urban seismic risk assessment and mitigation. Historic urban layout, architectural deployment of masonry, and extent of retrofits were recorded through onsite visual surveys via Geographical Information Systems and three-dimensional representation technologies. Extending the scope of information collected for engineering seismic risk assessment by focusing on the historical architectural context informs the selection of future mitigation measures. Oamaru, Winton, and Invercargill present intriguing case studies for multidisciplinary analysis, prior to testing urban-scale survey approaches within comparable historic centers across New Zealand. [ABSTRACT FROM AUTHOR]

The first real-time digital strong-motion network in Central Asia has been installed in the Kyrgyz Republic since 2014. Although this network consists of only 19 strong-motion stations, they are located in near-optimal locations for earthquake early warning and rapid response purposes. In fact, it is expected that this network, which utilizes the GFZ-Sentry software, allowing decentralized event assessment calculations, not only will provide useful strong motion data useful for improving future seismic hazard and risk assessment, but will serve as the backbone for regional and on-site earthquake early warning operations. Based on the location of these stations, and travel-time estimates for P- and S-waves, we have determined potential lead times for several major urban areas in Kyrgyzstan (i.e., Bishkek, Osh, and Karakol) and Kazakhstan (Almaty), where we find the implementation of an efficient earthquake early warning system would provide lead times outside the blind zone ranging from several seconds up to several tens of seconds. This was confirmed by the simulation of the possible shaking (and intensity) that would arise considering a series of scenarios based on historical and expected events, and how they affect the major urban centers. Such lead times would allow the instigation of automatic mitigation procedures, while the system as a whole would support prompt and efficient actions to be undertaken over large areas.

Seismic isolators are passive control devices that reduce the energy transferred from an earthquake to the superstructure, this avoiding damage to building elements. Seismic isolators are classified according to their connection to the structure; for example, unbonded isolators lack mechanical connections with the building. Unbonded fiber-reinforced elastomeric isolators (U-FREIs) are formed of intercalated layers of bidirectional polyester mesh used as reinforcement and agglomerated ground rubber from end-of-life tires (ELTs) as an elastomeric matrix. This paper presents the mechanical behavior of U-FREIs built at a reduced scale to provide an affordable alternative for the mitigation of seismic forces that affect low-rise buildings. The isolators were designed for a low-rise residential frame structure located in an area of high seismic hazard and were subjected to shear and compression tests to characterize their mechanical behavior. The experimental results show good behavior of the prototypes with respect to standards and design requirements. • Efficient solution for earthquake-risk mitigation in low-rise buildings. • Isolators are lighter and easier to assemble. • Deformations like those of natural rubber prototypes with the same reinforcement. [ABSTRACT FROM AUTHOR]

We present the results of a feasibility study of an earthquake early warning system (EEWS) for the Campania region (southern Italy) using schools as specific targets. The study considered the seismogenic zones as sources of potential earthquakes for the area, the Italian accelerometric network as the recording network for seismic event occurrence, and the performances of the software platform PRESTo for data analysis and processing. We analyze the distribution of lead-times for all possible threatening seismic sources for each municipality in the region under study by extracting the lead-time value corresponding to the 5th, 10th and 25th percentiles of the distributions. We discuss the results for the 5th percentile in order to analyze the worst-case scenario: in the case of a single site, the lead-time is expected to be larger than this value in the 95 % of the cases. Since the population distribution in Campania is uneven and most of the people live nearby the coast, whilst the most destructive earthquakes occur along the Apennine chain, we can conclude that an efficient EEWS can allow most of the schools in the area to undertake some mitigating actions. The testing of the EEWS was carried out in the high school ITIS 'E. Majorana', located at Somma Vesuviana, about 80 km from the seismogenic Irpinia region. For this purpose, the Sentinel, an actuator made up of low-cost hardware (i.e., Arduino), was developed in close cooperation with students and teachers of the school to receive alert messages from the PRESTo platform and warn the school users in case of a seismic event. The EEWS and the Sentinel were successfully tested during some blind drills performed during normal school activities. [ABSTRACT FROM AUTHOR]

The evolution of the expected earthquake losses in different Portuguese regions was studied in order to determine whether the natural regeneration of buildings could contribute to the mitigation of seismic risk, although the building exposure has increased over time in most analysed regions. To achieve this goal, five inter-related risk indicators were estimated, based on the Portuguese censuses' surveys of residential buildings and inhabitants obtained in two different moments in time: 2001 and 2011. The FEMA () approach was used to estimate the risk indicators, i.e., the Annualized Economic and Human earthquake Losses, either in absolute terms or normalised by building and population exposure. This study offers a perspective of the seismic risk in the Portuguese mainland, provides a comparison of risk levels between different epochs, and analyses the obtained results in order to compare the risk among Portuguese regions. It is important to mention that the comparison of economic losses based on the building stocks surveyed in 2001 and in 2011 took into account the Portuguese inflation rate in that time interval. The main findings of the study show that the natural regeneration of the residential housing stock contributes to the reduction of the expected seismic economic losses in Portugal, at an average rate of 14 % per 10 years, and to the reduction of the expected annualized human losses to almost one half after 10 years. The results support the conclusion that the natural regeneration of the residential housing stock contributed to the mitigation of the seismic risk in mainland Portugal, in the 10 year period under analysis, even though there was an increase of the building exposure in the region. [ABSTRACT FROM AUTHOR]

"Io Non Rischio - Terremoto (INR-T)" ("I Do Not Take Risks - Earthquake") is an Italian communication campaign created and promoted by the Italian Department of Civil Protection (DPC), the National Association for Public Assistance (ANPAS), the Italian Institute of Geophysics and Volcanology (INGV), and the Network of the University Laboratories of Seismic Engineering (ReLUIS). The rationale behind the campaign is that preventing or at least reducing the dangers associated with earthquakes is everyone's interest and duty. Learning how to do so, through an effective diffusion of information on seismic risk, fosters collective and individual responsibility, while encouraging active participation on the part of citizens. The INR-T campaign aims to promote a culture of seismic risk prevention, starting by training volunteers involved in civil protection activities, so that they can effectively and continuously help and encourage the public to take a more active role in seismic risk reduction. This paper describes the INR-T campaign and the activities that have led to an increasing number of involved volunteers and members of the public reached since the first edition (2011), until the fourth edition (2014). [ABSTRACT FROM AUTHOR]

In Turkey, seismic risk reduction in urban areas has gained significance since 1999 Marmara Earthquakes. As the launched legislations could not be integrated into land-use planning in a comprehensive way, homeowners has made the prior responsible for risk reduction. However, the factors that influence or constraint their risk reduction behavior in a voluntary environment are not known. This study intended to search out these factors to envisage suitable policies. Regarding the self-protective theories and their implementation in the natural hazard filed, the research has assessed the factors influencing homeowners' decision process for adopting risk mitigation measures. A questionnaire survey is designed and implemented in Zeytinburnu district of Istanbul. Accordingly, taking necessary measures seemed to be affected by house maintenance expenditure, house value and perceived responsibility of central government directly, whereas perceived losses and having children were likely to increase the reluctance of respondents. Based on the findings, linking house maintenance credits with adoption of risk mitigation measures, increasing house value with certification of buildings for adopting measures and providing special credits to homeowners with children can motivate homeowners for taking these measures. Moreover, community based risk mitigation programs that increase perceived responsibility of central government and district municipality can reduce the fatalistic behavior and unwillingness. [ABSTRACT FROM AUTHOR]

Inter-story isolation, an effective strategy for mitigating the seismic risk of both new and existing buildings, has gained more and more interest in recent years as alternative to base isolation, whenever the latter results to be impractical, technically difficult or uneconomic. As suggested by the name, the technique consists in inserting flexible isolators at floor levels other than the base along the height of a multi-story building, thus realizing a non-conventional Tuned Mass Damper (TMD). Consistent with this, an optimal design methodology is developed in the present paper with the objective of achieving the global protection of both the structural portions separated by the inter-story isolation system, that is, the lower portion (below the isolation system) and the isolated upper portion (above the isolation system). The optimization procedure is formulated on the basis of an energy performance criterion that consists in maximizing the ratio between the energy dissipated in the isolation system and the input energy globally transferred to the entire structure. Numerical simulations, performed under natural accelerograms with different frequency content and considering increasing isolation levels along the height of a reference frame structure, are used to investigate the seismic performance of the optimized inter-story isolation systems. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This article presents a new methodology to implement the concept of equity in regional earthquake risk mitigation programs using an optimization framework. It presents a framework that could be used by decisionmakers (government and authorities) to structure budget allocation strategy toward different seismic risk mitigation measures, i.e., structural retrofitting for different building structural types in different locations and planning horizons. A twostage stochastic model is developed here to seek optimal mitigation measures based on minimizing mitigation expenditures, reconstruction expenditures, and especially large losses in highly seismically active countries. To consider fairness in the distribution of financial resources among different groups of people, the equity concept is incorporated using constraints in model formulation. These constraints limit inequity to the user-defined level to achieve the equity-efficiency tradeoff in the decision-making process. To present practical application of the proposed model, it is applied to a pilot area in Tehran, the capital city of Iran. Building stocks, structural vulnerability functions, and regional seismic hazard characteristics are incorporated to compile a probabilistic seismic risk model for the pilot area. Results illustrate the variation of mitigation expenditures by location and structural type for buildings. These expenditures are sensitive to the amount of available budget and equity consideration for the constant risk aversion. Most significantly, equity is more easily achieved if the budget is unlimited. Conversely, increasing equity where the budget is limited decreases the efficiency. The risk-return tradeoff, equity-reconstruction expenditures tradeoff, and variation of per-capita expected earthquake loss in different income classes are also presented. [ABSTRACT FROM AUTHOR]

Pakistan is an earthquake-prone region due to its tectonic setting resulting in high hazard with moderate-to-strong ground motions and vulnerability of structures and infrastructures, leading to the loss of lives and livelihood, property damage and economic losses. Earthquake-related disaster in Pakistan is a regular and serious threat to the community; however, the country lack tools for earthquake risk reduction through early warning (pre-earthquake planning), rapid response (prompt response at locations of high risk) and pre-financing earthquake risk (property insurance against disaster). This paper presents models for physical damageability assessment and socioeconomic loss estimation of structures in Pakistan for earthquake-induced ground motions, derived using state-of-the-art earthquake loss estimation methodologies. The methodologies are being calibrated with the site-specific materials and structures response, whereas the derived models are tested and validated against recent observed earthquakes in the region. The models can be used to develop damage scenario for earthquakes (assess damaged and collapsed structures, casualties and homeless) and estimate economic losses, i.e., cost of repair and reconstruction (for a single earthquake event as well as all possible earthquakes). The models can provide help on policy- and decision-making toward earthquake risk mitigation and disaster risk reduction in Pakistan. [ABSTRACT FROM AUTHOR]