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With a view to providing general Storey Loss Functions (SLFs) for existing reinforced concrete (RC) residential buildings in Italy, this paper layouts the procedure and the development of SLFs for different residential building typologies, using post-earthquake observational damage data of the 2009 L'Aquila earthquake. To do so, the addressed building typologies and the cost ratios, with respect to the total construction cost, for structural and non-structural elements were defined according to the Italian price bulletin of building typologies, using the current average construction cost per square meter. Fragility models available in the literature, which had been specifically calibrated for structural and non-structural elements commonly found in Italian and Mediterranean RC buildings, were employed and the assumed repair costs were the ones incurred for repairing the buildings damaged during the 2009 L'Aquila earthquake. The proposed SLFs were then employed to perform loss assessment on a representative portfolio of Italian existing masonry-infilled RC residential buildings, showing the consistency of the results with respect to available research studies. The outcomes therefore denote how the proposed SLFs can be a useful tool as an alternative to the simplified conservative loss assessment guidelines currently employed in Italy, with a view to planning risk mitigation measurements both at a regional and single-building level. [ABSTRACT FROM AUTHOR]

The study reported in this paper concerns the temporal variation in the b-value of the Gutenberg–Richter frequency–magnitude law, applied to the earthquakes that struck Italy from 2009 to 2016 in the geographical areas of L'Aquila, the Emilia Region, and Amatrice–Norcia. Generally, the b-value varies from one region to another dependent on earthquake incidences. Higher values of this parameter are correlated to the occurrence of low-magnitude events spread over a wide geographical area. Conversely, a lower b-value may lead to the prediction of a major earthquake localized along a fault. In addition, it is observed that each seismic event has a different "occurrence time", which is a key point in the statistical study of earthquakes. In particular, its results are absolutely different for each specific event, and may vary from years to months or even just a few hours. Hence, both short- and long-term precursor phenomena have to be examined. Accordingly, the b-value analysis has to be performed by choosing the best time windows to study the foreshock and aftershock activities. [ABSTRACT FROM AUTHOR]

Analytical expressions for the floor spectra evaluation play a key role in the correct definition of the seismic input induced to non-structural elements or local mechanisms in existing buildings. They have to be able properly assessing the possible amplification phenomena, but also correctly describing the effects of nonlinearities due to structural damage. Due to the complexity of such phenomena, data on existing structures hit by earthquakes constitute a precious source for a better understanding of the topic and the validation of analytical expressions. In this framework, the paper aim is twofold. On one hand, it evaluates the entity of seismic amplification through experimental evidences from in-situ measurements on two existing monitored unreinforced structures. On the other hand, it presents the application on them of an analytical expression for the floor spectra already developed by the Authors. The case-studies are the former courthouse of Fabriano (Ancona, Italy) and the Pizzoli's town hall (L'Aquila, Italy). They were both hit by the 2016/2017 earthquake in Central Italy and are permanently monitored by the Italian seismic monitoring system of the Italian Department of Civil Protection. With the aim of validating the above-mentioned expression, the paper shows the comparison between experimental and analytical floor spectra for various minor events and mainshocks of the Central Italy earthquake. Since the two case-studies exhibited different damage levels (from slight to moderate, respectively), the comparison allowed us to verify the reliability of the expression both in the pseudo-elastic and moderate nonlinear fields. [ABSTRACT FROM AUTHOR]

Structural Health Monitoring (SHM) represents a very powerful tool to assess the health condition of buildings. In recent years, the growing availability of high-resolution SAR satellite images has made possible the application of multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) techniques for structural monitoring purposes, with high precision, low costs, timesaving, and the possibility to investigate wide areas. However, a comprehensive validation of the effectiveness of MT-InSAR in this application field has not been achieved yet. For this reason, in this paper a comparison between interferometric data and on-site measurement of displacements is proposed. The application case study is the Civic Tower of the city of L'Aquila (Abruzzo Region, Italy). After the seismic events that affected the area in 2009, an on-site monitoring system was installed on the tower to detect any changes in the damage pattern in the period 2010–2013. Furthermore, images acquired by COSMO-SkyMed constellation in Stripmap mode (~3 m resolution) during the same period were processed by the Permanent Scatterer-InSAR (PSI) technique to estimate the deformation of the structure and the surrounding area. The obtained results indicate that both methods are consistent in the measurement of displacement trends of the building and a slight rotation/displacement of the tower was detected. Such evidence highlights both the huge potential and the limitations of using InSAR techniques for SHM. [ABSTRACT FROM AUTHOR]

Post-earthquake reconstruction activities need tools for assessing the vulnerability of structures, based on visual inspection and quick survey. So far, the public administrations in charge of granting the funds and monitoring reconstruction have adopted different methods taken from scientific literature or developed ad hoc for specific events. The time is ripe for a standard method to be developed, treasuring from the lessons learned in the field. This paper proposes an expeditious tool based on visual survey for the assessment of the seismic vulnerability of unreinforced masonry buildings, starting from available methods, whose parameters were reassessed and recalibrated, and scientific evidence from recent literature. The influence of the main structural features was considered to calculate a vulnerability index in the 0–100 range. The effects of materials and arrangement of masonry were quantitatively evaluated through the masonry quality index, which represents an advancement with respect to current practice. The method was validated on a sample of 50 masonry aggregates and nearly 200 structural units of L'Aquila, Italy, where reconstruction is underway after a destructive earthquake in 2009. The sample is representative of the built heritage of other earthquake prone areas in Italy and many European Countries and the proposed method is a step forward the development of a standard tool to be used in future post-earthquake reconstruction scenarios. [ABSTRACT FROM AUTHOR]

This paper presents an insight on the seismic response and seismic risk of base-isolated structures performed within the RINTC project, considering different configurations of rubber-based isolation systems. This represents an in-depth revision of past works due to the adoption of more robust and accurate isolator model. Four archetype 6-storeys RC frame buildings are examined, representing both new designed isolated buildings and existing buildings retrofitted with seismic isolation, differing in age of construction and location (the cities of L'Aquila (central Italy) and Naples (southern Italy)). All the isolation systems are designed in accordance with the current Italian Seismic Code. Seismic performance assessment is performed by multi-stripe nonlinear time history analysis. The annual failure rates for two different performance levels, namely Global Collapse and Usability Preventing Damage, are computed. The results point out that all isolation systems work effectively in limiting damage while they show a quite low margin with respect to collapse, regardless of the dominant failure mode, which is governed by the more fragile component among isolation system and superstructure. The annual failure rates derived for base-isolated buildings are critically reviewed and then compared with those obtained for similar new designed fixed-base RC buildings. [ABSTRACT FROM AUTHOR]

The Department of Civil Protection (DPC), in compliance with the EU decision 1313/2013 and at the request of the Sendai Framework for Disaster Risk Reduction 2015–2030 to update the disaster risk assessments by various countries, released the latest National Risk Assessment for Italy at the end of 2018. Specifically, as regards the seismic risk assessment, six research units belonging to two centres of competence of the DPC collaborated under its guidance to update the risk maps of the Italian residential heritage. This extensive collaboration complied with the recent Italian code for Civil Protection, which requires a broad scientific consensus for risk assessment. During this research activity, six fragility models were developed, according to some common criteria (four for masonry buildings and two for RC buildings). These models were then implemented by the DPC for the definition of the national seismic risk. Within this context, the aim of this paper is to evaluate the risk results provided by these models, compare their features, and assess and validate their prediction capabilities. In particular, this paper shows the comparison of predicted and observed damage scenarios and consequences on building stock and the population of two seismic events, i.e. L'Aquila 2009 and Amatrice 2016. Furthermore, the paper provides some interesting damage and risk predictions at a national level. Overall, the forecasts and comparisons made in this study demonstrate the validity of the approach adopted by the DPC for the assessment of national seismic risk. [ABSTRACT FROM AUTHOR]

This paper presents a novel hybrid-based methodology devoted to develop urban fragility curves and damage probability matrices to predict likelihood seismic damage scenarios for small and medium Italian urban centres, considering URM buildings only. The concept of urban fragility curve consists of a single curve mean-representative of the seismic fragility of an entire area accounting for the combinations of building classes and their percentage, then they differ from those typological. The methodology has been developed with reference to Rocca di Mezzo, a small Italian urban centre located in the central Apennine area, Italy. Based on CarTiS inventory, building classes have been firstly recognized and urban fragility curves, representative for damage scenarios at Ultimate Limit State, developed. To predict damage scenarios from low to high-intensity earthquakes, an approach to define multi-damage urban fragility curves and damage probability matrices has been also presented. To this aim, a damage scale suffered by building classes has been defined by converting the final outcomes of the AeDES form (used in Italy for post-earthquake surveys) in the damage levels provided by the European Macroseismic Scale (EMS98). Data coming from urban fragility curves have been compared with the actual damage scenario recorded in Rocca di Mezzo after the 2009 L'Aquila's earthquake, in terms of both peak-ground acceleration and Mecalli-Cancani-Sieberg scale. The achieved results showed a good accordance between theoretical predictions and actual damage scenarios, coherent also with the damage scenarios occurred in other Italian historical centres hit by severe earthquakes over the years. Thus, the methodology can provide a first important indicator to support the development of emergently plans devoted to identify priority of interventions in such areas particularly vulnerable with respect to others. [ABSTRACT FROM AUTHOR]

Drawing on socio-psychology and economics literature contributions, this paper provides an original conceptual framework examining whether and how natural disasters exert any influence on nuptiality. Scholars suggest that disasters remind people about the transience of life and mortality. This feature triggers shifting towards intrinsic meaningful goals — such as commitment to relationships; at the same time, it fosters people's proximity and support-seeking from their security providing attachment figures and leads to accelerate life transition choices. In this view, disasters are expected to positively impact on people's intentions to marry. Such an effect is evident in case of natural hazards determining slight damage to physical capital (buildings, productive locations, etc.) which have limited economic consequences that do not hamper marriage intentions. Meanwhile, in the case of highly disruptive disasters, these positive psychological pushes are counterbalanced or even exceeded by the negative economic consequences of the disaster, which inhibit marriage intentions. These predictions are supported by an empirical analysis that relies on a difference-in-differences investigation of municipality-level nuptiality data collected in the Abruzzo region of Italy before and after the major 2009 L'Aquila earthquake. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to critically examine the "knowledge city" spatial socio-economic imaginary used in the post-earthquake city of L'Aquila, Italy, to promote its socio-economic redevelopment. Design/methodology/approach: The paper counters primary and secondary data with the expected qualities of a knowledge city. The analysis is supported by the literature review on knowledge-cities and post-disaster redevelopment, local and national documentation review, on-site observations and an inquiry of the case of the Gran Sasso Science Institute, the leading project towards the implementation of the knowledge-city agenda through interviews with key actors and a survey among its researchers. Findings: Post-disaster realities and path-dependency leave little room for a positive path-shaping redevelopment trajectory related to a knowledge-city urban archetype. This vision promotes materialism and intellectualism from local, national and international stakeholders; however, the city lacks specific urban qualities to attract and maintain highly skilled labour and investments, while negative socio-economic trends still continue a decade after the earthquake. Research limitations/implications: The city's post-disaster recovery and redevelopment contain certain degrees of inertia. The early stage of it, the lack of certain secondary data, and the focus of the paper on specific indicators limit the opportunity for stronger reasoning. Originality/value: The analysis reveals that the redevelopment vision of the knowledge city was hastily adopted. The mismatch between reality and expectations highlights the need for post-disaster territories to avoid overestimation of their capabilities and adjusts their redevelopment strategies to local characteristics adopting modest future projections. [ABSTRACT FROM AUTHOR]

This paper reflects on what materialised during recovery operations following the earthquake in L'Aquila, Italy, on 6 April 2009. Previous critiques have focused on the actions of the Government of Italy and the Department of Civil Protection (Protezione Civile), with little attention paid to the role of local authorities. This analysis sheds light on how the latter used emergency powers, the command‐and‐control approach, and top‐down planning to manage the disaster context, especially in terms of removal of rubble, implementing safety measures, and allocating temporary accommodation. It discusses how these arrangements constituted the mechanism via which 'disaster capitalism' took hold at the local and national level, and how it violated human rights, produced environmental and social impacts, hindered local communities from learning, transforming, and building resilience, and facilitated disaster capitalism and corruption. To make the disaster risk reduction and resilience paradigm more effective, a shift from centralised civil protection to decentralised, inclusive community empowerment systems is needed. [ABSTRACT FROM AUTHOR]

In this paper, empirical fragility curves for reinforced concrete buildings are derived, based on post-earthquake damage data collected in the aftermath of earthquakes occurred in Italy in the period 1976–2012. These data, made available through an online platform called Da.D.O., provide information on building position, building characteristics and damage detected on different structural components. A critical review of this huge amount of data is carried out to guarantee the consistency among all the considered databases. Then, an in-depth analysis of the degree of completeness of the survey campaign is made, aiming at the identification of the Municipalities subjected to a partial survey campaign, which are discarded from fragility analysis. At the end of this stage, only the Irpinia 1980 and L'Aquila 2009 databases are considered for further elaborations, as fully complying with these criteria. The resulting database is then integrated with non-inspected buildings sited in less affected areas (assumed undamaged), to account for the negative evidence of damage. The PGA evaluated from the shakemaps of the Italian National Institute of Geophysics and Volcanology (INGV) and a metric based on six damage levels according to EMS-98 are used for fragility analysis. The damage levels are obtained from observed damage collected during post-earthquake inspections through existing conversion rules, considering damage to vertical structures and infills/partitions. The maximum damage level observed on vertical structures and infills/partitions is then associated to the whole building. Fragility curves for two vulnerability classes, C2 and D, further subdivided into three classes of building height, are obtained from those derived for specific structural typologies (identified based on building height and type of design), using their frequency of occurrence at national level as weights. [ABSTRACT FROM AUTHOR]

Seismic risk assessment at the territorial level is now widely recognised as essential for countries with intense seismic activity, such as Italy. Academia is called to give its contribution in order to synergically deepen the knowledge about the various components of this risk, starting from the complex evaluation of vulnerability of the built heritage. In line with this, a mechanics-based seismic fragility model for Italian residential masonry buildings was developed and presented in this paper. This model is based on the classification of the building stock in macro-typologies, defined by age of construction and number of storeys, which being information available at national level, allow simulating damage scenarios and carrying out risk analyses on a territorial scale. The model is developed on the fragility of over 500 buildings, sampled according to national representativeness criteria and analysed through the Vulnus_4.0 software. The calculated fragility functions were extended on the basis of a reference model available in the literature, which provides generic fragilities for the EMS98 vulnerability classes, thus obtaining a fragility model defined on the five EMS98 damage states. Lastly, to assess the reliability of the proposed model, this was used to simulate damage scenarios due to the 2009 L'Aquila earthquake. Overall, the comparison between model results and observed damage showed a good fit, proving the model effectiveness. [ABSTRACT FROM AUTHOR]

Electromagnetic emissions in thermal infrared bands are an important research topic on pre-earthquake studies. Satellite thermal data have been investigated by many independent research groups looking for their anomalous behaviour before main earthquake's occurrences. Among them, geosynchronous satellite data are reported as less prone to artefacts during data processing. In this work, the Night Thermal Gradient (NTG) algorithm is presented, which has been specifically proposed for geostationary thermal infrared data processing. NTG method relies on the exploitation of high temporal resolution data to find coherent low frequency components of a hypothetical precursory signal of seismic activity. In this paper, the method is presented by giving details about the applied procedures, steps, theoretical assumptions and results obtained during the studies of L'Aquila 2009 earthquake and the seismic activity of Central Italy and Sardinia. [ABSTRACT FROM AUTHOR]

Extreme natural events require effective emergency procedures to minimize adverse effects on a region's population and economy. Such procedures typically involve the effort of several different teams of first responders (e.g., fire fighters, public administrations, police departments, utility companies), hence coordination is fundamental to the effectiveness of the response to the emergency that must be supported with adequate infrastructures. Nonetheless, first responders often rely on manual processes, in the life cycle of extreme events, which do not change consistently with the type of shock or affected population. The aim of this paper is to present a technology transfer process to improve both the emergency alert process and the knowledge of disaster-type safety procedures through the implementation of a proposed platform. We also highlight a pilot application on a post-disaster case study—the province of L'Aquila (Abruzzi) in Italy. [ABSTRACT FROM AUTHOR]

This paper deals with the structural behaviour and the damage assessment of Italian "modern" masonry buildings during seismic events. "Modern" masonry buildings are characterized by a box-like structural behaviour, due to the presence of effective connections between horizontal floors and vertical load-bearing walls, which prevents local mechanisms such as the overturning of external façades during earthquakes. "Modern" masonry buildings were built in Italy since the first decades of XX century in those regions classified as seismic zone and since 1937 in the whole country, following the Italian code prescriptions that implicitly interdicted the erection of "ancient" masonry buildings. Starting from an in deep historical analysis of the Italian seismic codes' prescriptions for the design of "modern" masonry buildings, the typical characteristics of the most frequent structural typologies of unreinforced masonry buildings are outlined. Then, the typical damage mechanisms observed in "modern" masonry buildings damaged after the L'Aquila earthquake (2009) are reported in relation with both the global and local behaviour of the whole building and its structural elements. The analysis demonstrated that "modern" masonry buildings experienced a good box-like seismic performance, which avoided global or local collapses, but shown severe damage to piers and spandrels related to their reduced in-plane shear capacity. Given the lack of data on such kind of structural typology, this study is fundamental for understanding and modelling the seismic behaviour of "modern" masonry buildings designed before '80s according to different seismic design prescriptions and for defining effective strengthening solutions for reducing their seismic vulnerability. [ABSTRACT FROM AUTHOR]

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

This work is based on the retrospective analysis of several geophysical observations to search for possible lithosphere-atmosphere-ionosphere coupling effects in the preparatory phase of the Central Italy seismic sequence 2016–2017. The major seismic events occurred on 24 August 2016 (Mw 6.0 Amatrice earthquake), 30 October 2016 (Norcia mainshock, Mw 6.5) and on 18 January 2017 (four M5+ events close to Campotosto-Montereale). The work consists of a multi parametric approach over different observables from ground and space: the geomagnetic field (from satellites and observatories), atmospheric chemical/physical composition, with the comparison with other already published results from chemistry of groundwater and seismicity. In particular, we investigated the vector magnetic data from INGV ground L'Aquila and Duronia magnetic Observatories and ESA Swarm three-satellite constellation. In addition, we searched for anomalies in physical/chemical composition of the atmosphere using MERRA-2 climatological dataset over Central Italy before the start of the seismic sequence. Two anomalous conditions anticipating the seismic sequence by about 275 and 85 days from geomagnetic Observatories and by about 240 days from satellite have been found. Furthermore, two highly perturbed periods in atmosphere chemical/physical composition that precede by 200 and 150 days the start of seismic sequence have been discovered. A comparison with also other published papers' results to validate and integrate our findings is finally presented. We find a chain of some quasi synchronous anomalies and propose a global point of view demonstrating that the earthquake preparation phase affects the equilibrium of the Earth system producing anomalies from around a year in lithosphere, atmosphere and ionosphere. • Ground, atmospheric and ionospheric data are analysed before strong earthquakes. • Pre-earthquake effects are seen as a chain of processes. • We propose a global point of view of the earthquake preparation phase. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to offer a critical examination of the aftermath of the L'Aquila earthquake of 6 April 2009. It considers the elements of the recovery process that are unique or exceptional and endeavours to explain them. Design/methodology/approach: The analysis is based on a survey and synthesis of the abundant literature on the disaster, coupled with observations from the author's many visits to L'Aquila and personal involvement in the debates on the questions raised during the aftermath. Findings: Several aspects of the disaster are unique. These include the use of large, well-appointed buildings as temporary accommodation and the efforts to use legal processes to obtain justice for alleged mismanagement of both the early emergency situation and faults in the recovery process. Research limitations/implications: Politics, history, economics and geography have conspired to make the L'Aquila disaster and its aftermath a multi-layered event that poses considerable challenges of interpretation. Practical implications: The L'Aquila case teaches first that moderate seismic events can entail a long and difficult process of recovery if the initial vulnerability is high. Second, for processes of recovery to be rational, they need to be safeguarded against the effects of political expediency and bureaucratic delay. Social implications: Many survivors of the L'Aquila disaster have been hostages to fortune, victims as much of broader political and socio-economic forces than of the earthquake itself. Originality/value: Although there are now many published analyses of the L'Aquila disaster, as the better part of a decade has elapsed since the event, there is value in taking stock and making a critical assessment of developments. The context of this disaster is dynamic and extraordinarily sophisticated, and it provides the key to interpretation of developments that otherwise would probably seem illogical. [ABSTRACT FROM AUTHOR]

High Voltage Engineering has developed a high-current, light-ion 3.5 MV single-ended accelerator system to meet the stringent requirements on beam intensity and stability of the LUNA-MV project at Laboratori Nazionali del Gran Sasso (LNGS), L'Aquila, Italy. The accelerator has an all permanent magnet, 10 GHz ECR ion source to deliver intense beams of H (∼1 mA), He and C. The machine ensures energy stability below 10−5, terminal voltage ripple of 1.5 × 10−5 and uninterrupted operations time greater than 24 h as requested by LNGS. Various changes to the standard in-line Singletron accelerator were needed to satisfy these requirements. In this paper, we highlight design details about the accelerator and ECR source and present early performance results. [ABSTRACT FROM AUTHOR]

The number of seismic isolated buildings has increased in recent years in Italy. In particular, in the city of L'Aquila, mostly affected by the 2009 earthquake, many new seismic isolated buildings were built and seismic isolation systems were also incorporated into many existing buildings. The frequencies range in which these buildings operate is substantially different from that of classical buildings. In particular, the seismic isolation, allowing the periods of the first modes of vibration to be generally moved beyond 2 s, in the absence of local amplifications, drastically reduces the stresses on the structure due to seismic events. On the other hand, special conditions relating to the morphology and stratigraphy of soils can produce amplifications, even considerable, in the operating frequencies typical of such buildings. This appears to be the case for L'Aquila. The historical centre of the town, indeed, was founded on a terrace rising about 50 m above the Aterno riverbed and is formed by alluvial Quaternary breccias consisting of limestone clasts in a marly matrix over imposed to 200 m thick lacustrine sediments which lie over a 300-400 m deep calcareous bedrock. This geological context deeply affects the dynamic behaviour of the formations and the local seismic response on the surface. The microzoning studies outlined a large presence of low frequency amplification (about 0.4-0.6 Hz) in the historical centre. The paper focus on the proper assessment of the seismic action to adopt in low frequency amplification sites with reference to the current Italian seismic regulations, also in perspective to the design of seismic isolated buildings, and evaluate the effectiveness of 1D and 2D local seismic response methods to predict surface amplification effects. [ABSTRACT FROM AUTHOR]

This paper examines the problems of the seismic design of precast concrete structures as indicated by the effects of the L'Aquila earthquake of 2009. The behaviour of such structures on that occasion is analysed on the basis of detailed surveys performed on site on a relevant number of buildings just after the earthquake. Following this analysis, which points out the inadequacy of the cladding panel connections, the paper presents a systematic definition of the problem, examining the behaviour of the whole system of structure + panels. Proposals are made for the typology of one-storey buildings for industrial uses, some possible alternative solutions that ensure the stability of all the construction elements. Specific calculations for a typical precast building give the order of magnitude of the forces and/or displacements for which the connections are to be designed. [ABSTRACT FROM AUTHOR]

L'Aquila earthquake, which occurred on April 6, 2009, proved the high vulnerability of cultural heritage, with particular reference to churches. Damage assessment in the emergency was carried out on more than 700 churches with a methodology aimed at recognizing the collapse mechanisms in the different architectonic elements of the church. The method was developed after the earthquake in Umbria and the Marches (1997) and has been widely used in the last decade; this approach is also very useful for seismic prevention, as it allows one to single out the most vulnerable structures. Some examples are presented in this paper, representative of recurrent damage in the main elements of the church: the façade, the roof, the apse and the belfry. It emerges that, for a correct interpretation of damage and vulnerability, it is necessary a deep knowledge of local construction techniques and of the historic transformation sequence. Moreover, the bad behaviour of churches strengthened by modern techniques, such as the substitution of original timber roofs with stiff and heavy r.c. slabs, was observed. Starting from the observation of some case studies, the paper achieves some worth results, which may be useful for correctly driving future strengthening interventions. [ABSTRACT FROM AUTHOR]

Abstract: The University of L’Aquila plays a central role in the life of the city of L’Aquila from both cultural and economic perspectives. The buildings of the University, located mainly in three zones of the town, constitute a significant sampling of the different architecture typologies coexisting in the area, including examples of traditional masonry buildings together with modern constructions of architectural value. Ranging from the historical buildings Palazzo Carli, Palazzo Camponeschi and Palazzo Porcinari, located in the old town center, to the reinforced concrete buildings dating from the mid-90s, the buildings exhibit many different structural properties resulting from a variety of construction techniques, materials, and erection dates. The present paper focuses its attention on understanding the behavior of these buildings during the earthquake events that repeatedly struck the region of L’Aquila during the seismic sequence of April 2009. The purpose of the paper is to identify the probable causes of structural failure, paying particular attention to the recurrent collapse mechanisms associated with the different structural types. The paper contains a report of visual inspections conducted for the detection and assessment of damage, and presents an overview of the activities conducted by the Unità Operativa di Ingegneria Sismica, a work group within the Dipartimento di Ingegneria delle Strutture, delle Acque e del Terreno (DISAT-UOIS) of the University of L’Aquila. Preliminary numerical results concerning the seismic behavior of a few selected buildings are also presented, as obtained from three-dimensional finite element models simulating their structural response to different accelerograms registered in the area. [Copyright &y& Elsevier]

Most damaging earthquakes come as complex sequences characterized by strong aftershocks, sometimes by foreshocks and often by multiple mainshocks. Complex earthquake sequences have enormous seismic hazard, engineering and societal implications as their impact on buildings and infrastructures may be much more severe at the end of the sequence than just after the mainshock. In this paper we examine whether historical sources can help characterizing the rare earthquake sequences of pre-instrumental times in full, including fore-, main- and aftershocks. Thanks to the its huge documentary heritage, Italy relies on one of the richest parametric earthquake catalogues worldwide. Unfortunately most current methods for assessing seismic hazard require that earthquake catalogues be declustered by removing all shocks that bear some dependency with those identified as mainshocks. We maintain that this requirement has led most modem historical seismologists to focus mainly on mainshocks rather than also on the fore- and aftershocks. To shed light onto major earthquake sequences of the past, rather than onto individual mainshocks, we investigated 10 damaging earthquake sequences (Mw 4.7-7.0) that hit the L'Aquila area and central Abruzzo from the 14th to the 20th century. We find that most of the results of historical research are important for modem seismology, yet their rendering by the current parametric catalogues causes most information to be lost or not easily transferred to the potential users. For this reason we advocate a change in current strategies and the creation of a more flexible standard for storing and using all the information made available by historical seismology. [ABSTRACT FROM AUTHOR]

The aim of Sustainable Development Goal 7 is to ensure access to affordable, reliable, sustainable and modern energy for all. Increased energy efficiency is particularly important in the construction industry because urban agglomerations currently consume up to 80% of global energy, 40% of which is attributable to buildings. In countries like Italy however, where historical buildings constitute a significant part of the building patrimony, improving energy efficiency is not always straightforward as interventions must take into account the historical materials used as well as the context of the construction. Therefore, the aim of this research was to establish a methodology that would identify the most effective means of achieving energy efficiency taking into account the historical aspects of a building and its cultural context. The methodology proposed and described in this paper involves: preliminary analyses to identify the elements of value and the level of transformability of facades; the selection of different insulating materials; dynamic simulations of building behaviour; analyses of intervention costs in relation to each type of insulation and finally the preparation of a multi-criteria matrix to identify the most effective method of improving energy efficiency of a historical wall with differing degrees of transformability. Each insulating material was analysed in relation to heating and cooling requirements and material cost impact. The methodology was applied to a case study in the Province of L'Aquila, Italy. In the paper a multicriteria framework, for the improvements in the thermal efficiency of a building, it is presented. Specifically the attention is focused on heating requirements, cooling requirements and cost impact. The results indicate that, with respect to historical building, it is possible to adopt strategies finalyzed to improve the energy efficiency of these buidings, contributing in this way, also toward the SDG7. Specifically, the best performance for a wall with a high level of transformability can be obtained using calcium silicate, extruded polystyrene, kenaf and hemp, whilst, in the case of a wall with a low level of transformability, the best materials are calcium silicate, polyurethane and linen fiber. Finally, in the case in which external constraints prevent the application of a thick coat and internally there is limited space, the use of calcium silicate was found to be the best energy efficient measure. [ABSTRACT FROM AUTHOR]

Italy is an earthquake-prone country and its disaster emergency response experiences over the past few decades have varied greatly, with some being much more successful than others. Overall, however, its reconstruction efforts have been criticised for being ad hoc, delayed, ineffective, and untargeted. In addition, while the emergency relief response to the L'Aquila earthquake of 6 April 2009-the primary case study in this evaluation-seems to have been successful, the reconstruction initiative got off to a very problematic start. To explore the root causes of this phenomenon, the paper argues that, owing to the way in which Italian Prime Minister Silvio Berlusconi has politicised the process, the L'Aquila reconstruction endeavour is likely to suffer problems with local ownership, national/regional/municipal coordination, and corruption. It concludes with a set of recommendations aimed at addressing the pitfalls that may confront the L'Aquila reconstruction process over the next few years. [ABSTRACT FROM AUTHOR]

This paper is focused on the illustration of on site works developed on some historical centres struck by L'Aquila earthquake of April 6, 2009 starting from the first emergency phase. The large number of minor historical centres damaged and the highly differentiated level of damage occurred implied the need of different procedures to study them. The common goal of all these studies is to illustrate the variability of the seismic response of historical masonry buildings trying to identify both the causes that have increased the damage (vulnerabilities) and the factors that have limited or prevented it (strengths). The preliminary results allow to formulate a first evaluation in view of drawing up reconstruction plans. [ABSTRACT FROM AUTHOR]

The ability to predict earthquakes is one of the greatest challenges for Earth Sciences. Radon has been suggested as one possible precursor, and its groundwater anomalies associated with earthquakes and water-rock interactions were proposed in several seismogenic areas worldwide as due to possible transport of radon through microfractures, or due to crustal gas fluxes along active faults. However, the use of radon as a possible earthquake's precursor is not clearly linked to crustal deformation. It is shown in this paper that uranium groundwater anomalies, which were observed in cataclastic rocks crossing the underground Gran Sasso National Laboratory, can be used as a possible strain meter in domains where continental lithosphere is subducted. Measurements evidence clear, sharp anomalies from July, 2008 to the end of March, 2009, related to a preparation phase of the seismic swarm, which occurred near L'Aquila, Italy, from October, 2008 to April, 2009. On April 6th, 2009 an earthquake (M = 6.3) occurred at 01:33 UT in the same area, with normal faulting on a NW-SE oriented structure about 15 km long, dipping toward SW. In the framework of the geophysical and geochemical models of the area, these measurements indicate that uranium may be used as a possible strain meter in extensional tectonic settings similar to those where the L'Aquila earthquake occurred. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we demonstrate that the seismic sequence of foreshocks culminating with the recent M w =6.3 main shock on April 6, 2009 in L''Aquila (Central Italy) evolved as a chaotic process. To do this, we apply a nonlinear retrospective prediction to this seismic sequence and look at the temporal behaviour of the error between predicted and actual occurrence of the main shock when gradually increasing parts of the sequence are considered. This is a generalisation of the typical nonlinear approach which is quite powerful to detect chaos in relatively short time series. The method of prediction is based on the Accelerated Strain Release (ASR) analysis in time and on the nonlinear forecasting approach in a reconstructed phase space. We find that i) the temporal decay of the prediction error is consistent with an exponential function with a time constant τ of about 10days and ii) at around 6days before the main shock, ASR analysis is quite powerful for anticipating the time of occurrence with an uncertainty of about a day. Due to its retrospective characteristics, the latter result could be affected by changes on some a-priori parameters used in the application of the ASR technique. However, we consider these findings, together with those obtained from the phase-space analysis, to be strong evidence that the studied sequence of foreshocks was produced by a physical process dominated by a significant chaotic component characterised by a K-entropy=1/τ of about 0.1day−1. This result could have important implications for the predictability of the possible main shock for those seismic sequences showing analogous nonlinear chaotic properties. [Copyright &y& Elsevier]

An earthquake sequence struck the province of L'Aquila (central Italy) leaving 305 dead, about 1,500 injured, and 29,000 homeless. Hundreds of low-intensity events occurred between January and March, 2009. The mainshock took place on April 6, 2009, and its epicenter was located at about 6 km southwest of L'Aquila town; three stronger aftershocks happened on April 7 and 9, 2009. This paper focuses on actual performance of older and more recently constructed building structures during the earthquake sequence. After the main seismological characteristics of the sequence are described, the most significant observed damages are analyzed and associated with theoretical failure modes for both reinforced concrete and unreinforced masonry buildings. Since older masonry structures were more seriously damaged, the effects of the earthquake are described with more emphasis to ordinary masonry and cultural heritage buildings (churches, palaces, and castles). In conclusion, a number of lessons may be learned from the L'Aquila earthquake sequence. Several features are highlighted and some proposals are given to upgrade the current methods of structural analysis, as well as the existing codes. [ABSTRACT FROM AUTHOR]

This paper aims to describe the seismic-driven multi-hazard scenario of the Lake Campotosto artificial basin (Abruzzo Region, Central Italy), and it can represent a preparatory study for a quantitative multi-hazard analysis. A comprehensive multi-hazard scenario considers all the effects that can occur following the base ground shaking, providing a holistic approach to assessing the real hazard potential and helping to improve management of disaster mitigation. The study area might be affected by a complex earthquake-induced chain of geologic hazards, such as the seismic shaking, the surface faulting of the Gorzano Mt. Fault, which is very close to one of the three dams that form the Lake Campotosto, and by the earthquake-triggered landslides of different sizes and typologies. These hazards were individually and qualitatively analyzed, using data from an engineering-geological survey and a geomechanical classification of the rock mass. With regard to the seismic shaking, a quantitative evaluation of the seismic response of the Poggio Cancelli valley, in the northern part of Lake Campotosto, was performed, highlighting different seismic amplification phenomena due to morphologic and stratigraphic features. Some insights about the possible multi-hazard approaches are also discussed. [ABSTRACT FROM AUTHOR]

Monitoring infrastructures is becoming an important and challenging issue. In Italy, the heritage consists of more than 60,000 bridges, which need to be inspected and detected in order to guarantee their strength and durability function during nominal lifespan. In this paper, a non-destructive survey methodology for study concrete bridges surface deterioration and viaducts is presented. Terrestrial and unmanned aerial vehicle (UAV) photogrammetry has been used for visual inspection of a standard concrete overpass in L'Aquila (Italy). The obtained orthomosaic has been processed by means of Object-Based Image Analysis (OBIA) to identify and classify deteriorated areas and decay forms. The results show a satisfactory identification and survey of deteriorated areas. It has also been possible to quantify metric information, such as width and length of cracks and extension of weathered areas. This allows to perform easy and fast periodic inspections over time in order to evaluate the evolution of deterioration and plan urgency of preservation or maintenance measures. [ABSTRACT FROM AUTHOR]

The great influence of site effects on damage patterns produced by seismic events of the past, stresses out the need to find proper relationships between the site local conditions and the potential damage that existing buildings may experience under earthquakes of different intensity. This issue proved to be relevant, especially for those masonry buildings in small historic centers, such as the ones belonging to the Apennine areas of Italy that suffered serious damage after the 2009 L'Aquila and the 2016–2017 Central Italy seismic sequences. Some of these centers showed a not regular damage distribution, suggesting that site effects influenced the seismic response of their buildings. In this perspective, this paper provides an attempt to correlate earthquake damage to site effects, focusing the attention on two historic centers of the Abruzzi region, Campotosto and Cortino, which were damaged by the 2016–2017 Central Italy seismic sequences and for which the amplification factors of the subsoil were carefully identified, resulting more influencing were higher damage was observed. First, the damage patterns observed after the 18 January 2017 seismic shock are represented in terms of Damage Probability Matrices and maps developed in GIS environment. Moreover, the data collected in terms of stats are interpreted through the application of the binomial probability distribution, in order to check its reliability in reproducing the gathered frequencies. Finally, in order to justify the damage of some specific buildings, the results of site response analyses are compared with the damage observed punctually on three damaged masonry buildings. • Damage Scenarios observed after the 2016 Central Italy Earthquakes on a Italian minor historic center have been put in relation with the results of a 3rd level Micro zonation study. • The binomial distribution proved to work well when buildings affected by site amplification effects are not included in the scenario; • The different damage levels observed after the earthquake have been justified according to the analysis of the average spectral acceleration measured for their esteemed frequencies and accounting for site amplification effects. [ABSTRACT FROM AUTHOR]

During the last 20 years (1997 to 2017), four seismic sequences with Mw ≥ 5.5 mainshocks nucleated along the Central and Northern Apennines chain (Italy), causing casualties and damage: the 1997 Colfiorito, the 2009 L'Aquila, the 2012 Emilia, and the most recent 2016–2017 Central Italy seismic sequences. In this work, we perform a novel joint analysis of seismological and remote-sensing data to achieve new insights into the faulting process evolution during the considered seismic sequences. To this aim, we study these seismic sequences by exploiting the available seismological data and by applying fractals theory to them. In particular, we characterize the different behavior of compressional and extensional seismic sequences by examining the temporal evolution of the fractal dimension values. In addition, we compare the Differential Synthetic Aperture Radar Interferometry (DInSAR) displacement maps relevant to the considered seismic events (already published in our past papers) and the performed spatial and temporal seismological analyses, in order to emphasize some significant aspects of the different faulting processes active during these Italian seismic sequences. The analysis of the fractal dimension values shows that over time extensional seismic sequences are spatially distributed within a volume, whereas compressional ones are aligned along a preferential surface. These spatio-temporal patterns are confirmed by: (1) the spatial distribution of hypocenters for the events that occurred between the mainshock and the post-seismic synthetic aperture radar (SAR) acquisition; (2) the spatial extension of coseismic DInSAR ground-deformation patterns. The proposed seismic and ground-deformation analyses can thus typify different geodynamic contexts in Italy, providing a distinct image of articulated faulting processes. [ABSTRACT FROM AUTHOR]

In this article, the authors reply to a discussion on their article "Introspection on improper seismic retrofit of Basilica Santa Maria di Collemaggio after 2009 Italian earthquake," which appeared in a previous issue of the journal. They inform that the information revealing the importance of the global effects of stiffening and strengthening produced by the retrofit interventions of the church Santa Maria di Paganica and Collemaggio Basilica L'Aquila, Italy are presented in the original paper. They also comment on the addition of horizontal truss to the structure of the church. strengthening and damping produced by the retrofit interventions of were presented in the original paper. They also asked the discusser to read the MCEER report for the scheme of correct position of reticular truss. They concludes that by adding horizontal truss to the structure of church, the seismic load has been shifted to facade and transept out of which facade supportes the additional load while the transept did not.