Seismic Risk Assessment

The seismic risk mitigation from the perspective of the old buildings stock is truly essential in Algerian urban areas, particularly those located in seismic prone regions, such as Annaba city, and which the old buildings present high levels of degradation associated with no seismic strengthening and/or rehabilitation concerns. In this sense, the present paper approaches the issue of the seismic vulnerability assessment of old masonry building stocks through the adaptation of a simplified methodology developed for a European context area similar to that of Annaba city, Algeria. Therefore, this method is used for the first level of seismic vulnerability assessment of the masonry buildings stock of the old city center of Annaba. This methodology is based on a vulnerability index that is suitable for the evaluation of damage and for the creation of large-scale loss scenarios. Over 380 buildings were evaluated in accordance with the referred methodology and the results obtained were then integrated into a Geographical Information System (GIS) tool. Such results can be used by the Annaba city council for supporting management decisions, based on a global view of the site under analysis, which led to more accurate and faster decisions for the risk mitigation strategies and rehabilitation plans.

The authors consider the gravitational precursors of Mega Ear thquakes in Asia and Southeast Asia: Sichuan earthquake, M7.9, May 12, 2008; Andaman Islands earthquake, M7.5, August 10, 2009; Samoa Islands earthquake, M8.1, September 29, 2009; Northern Sumatra earthquake, M7.8, April 06,2010; Tohoku earthquake, M9, March 11, 2011.
All gravitational precursors were recorded using of ATROPATENA earthquake prediction stations. The creation of an international earthquake prediction system based on the results obtained is proposed. To monitor spatio-temporal variations of the gravitational
field, special detectors named ATROPATENA stations have been developed and made.
The detectors continuously measure the value of the gravitational constant G in mutually perpendicular directions and relative values of gravity Δg. Before and after the Mega Earthquakes in Asia and Southeast Asia, variations of the Earth’s gravitational field were
registered at large distances from the epicenter (near 8000 km); they were measured with the ATROPATENA stations in the following location: Baku (Azerbaijan) and Yogyakarta (Indonesia). Indications of the Cavendish balance when measuring the gravitational constant
G are influenced by spatio-temporal changes in external gravitational fields of geological origin, which alter over time indications of the true values of G. Measuring the true value of the gravitational constant G on the Earth’s surface with accuracy greater than the second digit after the decimal point is not possible due to the spatio-temporal variations of the gravitational field as a result of the impact of geodynamic processes.
For the first time, the true cause of variations of the recorded values of the gravitational constant G has been identified. These variations were the subject of scientific dispute throughout the last century.

Existing Reinforced Concrete buildings, even when designed according to former technical standards for construction in seismic areas, have been shown not to have the characteristics of structural ductility necessary to ensure a sufficient level of performance for the occurrence of earthquakes of even moderate intensity. The occurrence of sudden collapse of modern buildings emphasizes the urgency of a thorough examination of existing buildings in areas characterized by intense seismic activity.
In other countries where the phenomenon is of similar proportions so-called intervention programs have been processed. These programs consist of an examination of existing buildings in regions of high seismic activity and subsequent identification of cases where there is no guarantee of an acceptable
degree of safety. The development of the whole process of identification of unsafe buildings, is made to depend from a preliminary stage of evaluation of the fragility. This can be pursued through two different methodologies: rapid assessment and detailed assessment. In the Rapid Assessment process the membership of a building to a class of vulnerability is assessed through the use of scores to be completed by visual inspection. The Detailed Assessment will define the properties of generalized resistance of the building.
The data derived from the Rapid Assessment may be used in analysis scenarios, in which the damage level of a building is evaluated in correspondence of the occurrence of a seismic event of a predetermined intensity. Trough the examination of scenarios of entire areas, buildings are identified on which the Detailed Assessment procedure is to be performed, the buildings for seismic risk highlighted by this analysis are then, within a specified time frame, subject to the work of reinforcement.
Because often Reinforced Concrete buildings have features that make it impractical to apply a simplified evaluation criteria, the present study focuses on in-depth evaluation methods for detailed assessment of the fragility, with the aim to illustrate the degree of applicability to real cases.
The deepening of these methods will attempt to highlight conceptual differences and the different degree of approximation, application of different methods on a real case is presented to provide the possibility of a direct comparison of the results obtained.

Earthquake is a calamity that causes sudden shaking of the ground due to the release of stress within the rocks along the faults or by the volcanic activity. Earthquake may cause massive damage to structures that is not properly designed to withstand it or that is damaged over the long run of its lifeline. Philippines is one the places near the Pacific Ring of fire which is an area in the Pacific Ocean with large number of volcanic activity present. With earthquake's unpredictable occurrence, it possesses the greatest threat to structures and is often the concern in the design of buildings and bridges. Failure to study the effect of an earthquake to a structure may cause not only property lost but also lives of many, due to this matter Seismic assessment is done to prevent or at least reduce the damage. Seismic assessment started long ago during the Spain colonization in the Philippines, observation of the effects to the structure after an earthquake by naked eye and documentation of each recorded effects has now evolved to different methods that analyses the performance of a building using calculations and software. The researchers will get the structural plan of the Plaridel Bridge from the DPWH and get the ground motion data. Next is the researchers will model the Plaridel Bridge using SAP2000 then evaluate the Nonlinear Static Analysis and Nonlinear Dynamic Analysis. And after the simulations, the researchers will gain the Seismic Fragility Curves. The research study will tackle the Non-linear Static Analysis or the Pushover Analysis, the Non-linear Dynamic Analysis or the Time History Analysis, the Ductility Factors and then gaining the Fragility curves. After the methods done to get the fragility curves, the results will show that Y direction is the stronger axis as it can withstand a larger shear force that the X direction can withstand. The results will also display that the damage rank As has the most number count but occurred mostly at higher peak

Reconnaissance studies following recent significant earthquakes have revealed the seismic vulnerability of curved bridges. Curved steel bridges are widely utilized as important components of transportation networks across the United States especially when geometry and curve alignment of a highway requires a curved structure. However, there are a few studies regarding the seismic vulnerability of horizontally curved steel girder bridges as one of the most critical components of transportation networks.
Comprehensive and rational evaluation of seismic vulnerability of transportation networks can be achieved through methodological Seismic Risk Assessment (SRA). Fragility curves which express the conditional probability of reaching or exceeding a predefined damage state are essential as input to any SRA tools such as HAZUS and REDARS for the seismic vulnerability evaluation. This study aims to fill in the gap on
the current state-of-the-knowledge in the seismic response and fragilities of horizontally curved bridges with steel I-girders.

This article introduces a generic modeling approach that is suitable for static and dynamic analysis,
and response assessment of highway bridges with varying levels of irregularities. The proposed
approach and modeling recommendations are based on grillage modeling rules that allows explicit
representation of various types of details and components. The validity and accuracy of the proposed
approach is demonstrated against three-dimensional finite element models as well as experimentally
recorded response various benchmark bridges. While achieving remarkable accuracy, the
required analysis time was also reduced up to 80%, making the proposed approach suitable for
computationally intensive studies.

Abstract. Rapid loss estimation after potentially damaging earthquakes is critical for effective emergency response
and public information. A methodology and software package,
ELER-Earthquake Loss Estimation Routine, for rapid
estimation of earthquake shaking and losses throughout the
Euro-Mediterranean region was developed under the Joint
Research Activity-3 (JRA3) of the EC FP6 Project entitled
“Network of Research Infrastructures for European
Seismology-NERIES”. Recently, a new version (v2.0) of
ELER software has been released. The multi-level methodology
developed is capable of incorporating regional variability
and uncertainty originating from ground motion predictions,
fault finiteness, site modifications, inventory of physical
and social elements subjected to earthquake hazard and
the associated vulnerability relationships. Although primarily
intended for quasi real-time estimation of earthquake
shaking and losses, the routine is also equally capable of incorporating
scenario-based earthquake loss assessments.
This paper introduces the urban earthquake loss assessment
module (Level 2) of the ELER software which makes
use of the most detailed inventory databases of physical and
social elements at risk in combination with the analytical vulnerability
relationships and building damage-related casualty
vulnerability models for the estimation of building damage
and casualty distributions, respectively. Spectral capacitybased
loss assessment methodology and its vital components
are presented. The analysis methods of the Level 2 module,
i.e. Capacity Spectrum Method (ATC-40, 1996), Modified
Acceleration-Displacement Response Spectrum Method
(FEMA 440, 2005), Reduction Factor Method (Fajfar, 2000)
and Coefficient Method (ASCE 41-06, 2006), are applied to
the selected building types for validation and verification purposes. The damage estimates are compared to the results
obtained from the other studies available in the literature,
i.e. SELENA v4.0 (Molina et al., 2008) and ATC-55 (Yang,
2005). An urban loss assessment exercise for a scenario
earthquake for the city of Istanbul is conducted and physical
and social losses are presented. Damage to the urban
environment is compared to the results obtained from similar
software, i.e. KOERILoss (KOERI, 2002) and DBELA
(Crowley et al., 2004). The European rapid loss estimation
tool is expected to help enable effective emergency response,
on both local and global level, as well as public information

The article characterizes the seismic hazard and risk to which the territory of the Republic of Moldova is exposed. There are also addressed the existing problems which concern the monitoring of seismic events, zoning and seismic microzonation, as well as the seismic risk on the territory of the Republic of Moldova. In order to face the challenges conditioned by the future earthquakes, it is necessary to develop and apply a wide spectrum of scientific, political
and administrative measures.

Il saggio affronta il tema della conoscenza delle torri campanarie storiche nell’areale etneo, notoriamente esposto a rischio sismico e vulcanico. Sono proposti un censimento e una classificazione tipologica di questo importante e poco conosciuto patrimonio architettonico, per poi analizzare alcuni casi di studio emblematici. Vengono quindi individuati i caratteri formali e tecnico–costruttivi più ricorrenti e alcune labilità intrinseche, veri e propri “indicatori di vulnerabilità”. Il tutto rappresenta un quadro conoscitivo preliminare per qualsiasi intervento di restauro tale da garantire la sopravvivenza di queste emergenze architettoniche simbolo del paesaggio dei nostri centri storici.
https://www.aracne-editrice.it/index.php/pubblicazione.html?item=9788825535716

Response-history nonlinear dynamic analysis is an analytical tool that often sees use in risk-oriented earthquake engineering applications. In the context of performance-based earthquake engineering, dynamic analysis serves to obtain a probabilistic description of seismic structural vulnerability. This typically involves subjecting a nonlinear numerical computer model to a set of ground-motions that represent a sample of possible realizations of base acceleration at the site of interest. The analysis results are then used to calibrate a stochastic model that describes structural response as a function of shaking intensity. The sample size of the ground-motion record set is nowadays usually governed by computation-demand constraints, yet it directly affects the uncertainty in estimation of seismic response. The present study uses analytical and numerical means to investigate the record sample size, n, required to achieve quantifiable levels of mean relative estimation error on seismic risk metrics. Regression-based cloud analysis in the context of Cornell's reliability method and incremen-tal dynamic analysis using various intensity measures were employed to derive a relation of the form Δ= ffiffiffi n p , where Δ is a parameter that depends on both the dispersion of structural responses and the shape of the hazard curve at the site. For the cases examined, n can be kept in the 40 to 100 range and achieve 10% mean relative error. The study can contribute to guide engineers towards an informed a-priori assessment of the number of records needed to achieve a desired value for the coefficient of variation of the estimator of structural seismic risk.

Mbeya city situated in southwest Tanzania is under potential for seismic hazard because of its vicinity toward the western and eastern intersection of The East Africa Rift Valley System (EARS). The EARS is viewed as a standout amongst the most seismically active areas in the African continent. This study attempt to investigate the state of seismic risk of a case-study building located in the city of Mbeya. The existing local seismic guideline namely BRU Technical Guideline was reviewed and analyzed, and its deficiency and inefficiency have been clearly described. Physical survey and inspection were also conducted. Modeling and analysis of the case study building were performed through numerical simulation. The model was then evaluated, and the most significant seismic deficiencies were identified. The case-study building is found to be earthquake-prone for values of peak ground acceleration (PGA) greater than 0.02g. The recommendations are then proposed to minimize the effect of future damaging earthquakes in the city.

In seismic risk mitigation policies, fragility functions of existing buildings play a fundamental role. In this paper, a procedure to develop analytical fragility curves for Moment Resisting Frame Reinforced Concrete buildings is presented. The design of the selected building typologies was performed according to the codes at the time of construction using force-based methods and the state of the practice at the time of construction. A total of 216 building classes were defined, considering different ages, number of storeys, infill panels, plan dimensions, beam stiffness, and concrete strength. The investigated buildings can be considered low-engineered buildings, using no seismic codes or old seismic codes. The seismic capacity of the selected models representing the existing RC buildings has been evaluated through non-linear dynamic simulations. Seismic response has been analyzed, considering various peak and integral intensity measures and various response parameters, such as ductility demands and Interstorey Drift Ratio (IDR). A new relationship among structural performance, damage levels and interstorey drift ratios for each studied type is introduced, which is calibrated using the damage levels described in EMS98. It is important to highlight that in this study, different thresholds of IDR have been associated with different typologies, considering their different ductility member levels after their different structural responses. Fragility Curves (FCs) for the studied structural types are set up, developed and discussed.

Earthquake risk can be quantified in terms of the estimated numbers of human casualties and of damaged buildings as well as the monetary losses. The information required for the assessment of earthquake risk in a given region includes the expected level of ground shaking intensity (i.e., the seismic hazard), inventory data for building stock at risk, identification of predominant building typologies and of their vulnerability characteristics , and spatial distribution of number of inhabitants. This study presents an indicative assessment of earthquake risk associated with the building stock in Muscat, the capital city of the Sultanate of Oman. For this purpose, building inventory and demographic data for the city are compiled in GIS environment. The buildings are classified to identify their damageability/vulnerability characteristics, and predominant building typologies are determined. For the estimation of casualties, Muscat population data are further analyzed to calculate number of occupants in the exposed building stock. Spectral acceleration– displacement based damage estimation methodology is implemented for risk calculations. Site-specific ground motions in terms spectral accelerations obtained from the probabilistic seismic hazard assessment for 475-and 2475-year return periods are considered for the representation of earthquake demand in damage analyses. Assessment of damage to buildings and estimation of casualties are obtained using analytical fragility relationships and building damage related casualty–vulnerability models, respectively. Earthquake risk maps illustrating the spatial distribution of number of damaged buildings at different damage states are presented for the considered levels of seismic hazard.

Exposure to seismic hazard in mines is controlled through various evacuation, exclusion and re-entry procedures. The aim of exposure management procedures is to tactically reduce the safety risk by removing personnel from work areas during periods of elevated seismic hazard. Given that risk assessment is based on exposure, the design of exposure management procedures must also be risk-based. In practice, the decision to re-enter a workplace after an exclusion is generally only made based on an assessment of the seismic hazard, often using previously defined levels of tolerable seismic activity rates. The definition of tolerable seismic hazard, in the context of re-entry, is seldom quantitatively assessed based on risk. In order to move towards a comprehensive seismic risk management strategy, design methodologies must be able to quantify the impact of different exclusion and re-entry practices on risk. The appropriate re-entry practice can then be selected given the defined risk-based design acceptance criteria. There is still a long way to go before the risk-based design framework for exposure management procedures is complete. This paper reviews the current state of design of exposure management controls in the context of risk and discusses several important areas for further research.

Gemsa has been chosen as the site for one of a new generation of power stations along the southwestern margin of the Gulf of Suez. This site has been affected by a number of destructive earthquakes (M w > 5), in addition to large number of earthquakes with magnitudes of less than 5. In this study seismic activities in the region were collected and re-evaluated, and the main earthquake prone zones were identified. It is indicated that this site is affected by the southern Gulf of Suez, northern Red Sea and Gulf of Aqaba source zones. The southern Gulf of Suez source zone is the nearest to the proposed site. The stochastic simulation method has been applied to estimate the Peak Ground Acceleration at the site of the proposed Gemsa power plant. It was noticed that the pseudo-spectral acceleration (PSA) reaches 175 cm/sec 2 resulting from the southern Gulf of Suez seismic source. In addition, the response spectrum was conducted with a damping value of 5% of the critical damping, and the predominant period reached 0.1sec at the site. These results should be taken into consideration by civil engineers and decision-makers for designing earthquake resistant structures.

Under the current landscape of digitalization of the main information services commonly used in our country in case of a serious emergency, the work exposes the
logical architecture of a particular digital information system for rescue external or internal areas to any kind of human settlement. Under the current western
procedures of risk management, since almost twenty years similar systems are now indispensable tools for decision support and making. The purpose of the proposed
system is to provide documentary evidence of the damage to architectural and industrial goods, in particular due to seismic disasters, and, in the meantime, to
provide an essential documentary basis relating to the temporary works of functional safety measures.

This paper makes the case for natural disaster emergency planning to be incorporated into sustainable tourism strategies, using seismic risk scenario planning as a technique, and
the Southern Alps of the South island of New Zealand as an example. The Alpine Fault is a 450-km-long geological structure running the length of the Southern Alps in New Zealand. Paleoseismic evidence suggests that a significant earthquake of magnitude (M)∼ 7.8–8.0 is overdue. Coincident with this area of high seismic potential is a growing tourism industry, capitalising on the region’s international reputation for nature-based
tourism experiences. The scenario planning approach uses an isoseismal modelling methodology to describe a range of specific vulnerabilities in the tourism sector and highlight the physical outcomes and consequences for tourism-related infrastructure, transport, food supply, rescue, and survival likely to result from a future M8 earthquake on the Alpine Fault. Interviews with hazard management agencies investigated how tourism is considered in the context of current hazard management policies, and the urgent need to bring industry policies into partnership with other planning agencies and policies. Risk management is shown to be essential to address the triple bottom line of sustainable tourism management.

Buried water pipelines are subjected to corrosion deterioration and are vulnerable to extreme events (e.g. earthquakes). Corroded metallic buried pipelines have experienced severe damage during past earthquakes resulting in the service disruption of Water Distribution System (WDS). Also, continuous and adequate water supply is imperative for fighting fires caused by the earthquakes. Therefore, evaluation of the functionality of WDS and its service restoration after an earthquake is very important for the water service provider as well as the communities.  This paper presents a framework to evaluate both component-level and system-level seismic risk and resilience of WDSs considering time-variant corrosion of pipelines. The vulnerability of individual pipelines is modelled by modifying the American Lifelines Alliance (ALA) pipeline vulnerability functions to explicitly account for the strength deterioration due to corrosion. Resilience is modelled using a functionality curve that relates system failure probability and repair activities over time. Probabilistic Functionality Fragility Surface (FFS) is developed for both components and system, by integrating the fragility curves and the restoration functions. The use of the proposed framework is demonstrated on two hypothetical water networks (i.e., one small scale and one medium scale).  The results of the two case studies show that the restoration process has a significant influence on the shape of the FFS.  Time to repair a break, number of breaks, network topology, the level of corrosion, and the available resources of utility companies are key parameters that determine the shape of the FFS. It is also observed that larger and older WDS networks experience a significantly higher number of breaks, which compromises their resilience. The proposed framework provides a useful planning tool for asset management of WDSs subjected to seismic hazards.

The aim of this paper is to develop a seismic risk assessment study of urban infrastructural systems relying on state-of-the-art tools for the prediction of earthquake ground motion as well as the assessment of vulnerability. The proposed approach makes use, on one hand, of 3D physics-based numerical simulations of source-to-site wave propagation problems to provide an accurate description of spatial variability of ground shaking and, on the other hand, of systemic approaches for the evaluation of the vulnerability of complex, interconnected urban systems. The city of Thessaloniki, in Northern Greece, is taken as case study and the physical damage and loss of performance for the main water supply system are estimated based on connectivity based performance indicators. A couple of rupture scenarios with magnitude MW equal to 6.5 and 7.0, breaking two major hazardous faults around the city are used. The results indicated that 3D simulations can efficiently and accurately account for near-source conditions, geological and site conditions at local scale as well as for spatial and cross-correlation of ground motion. The risk estimates are compared with the ones obtained using a standard approach based on Ground Motion Prediction Equations (GMPEs), accounting for the spatial variability of ground motion. It was concluded that the GMPEs based approach can be used for a preliminary and faster seismic loss
estimation. However, the results shed light on the main advantages of a full 3D numerical modeling for seismic risk assessment in large urban environments and spatially distributed systems. A major advantage is the more accurate estimation of spatial correlation of ground motion, which is location- and earthquake- specific.

Information on the seismic response of chemical containers located in storage racks is very limited. Unfortunately, no clearly established data and statistics exist related to potential damage of chemical racking systems during earthquakes. Hence, this work presents an approach for developing fragility curves for chemical racking systems in the cross-aisle direction through dynamic non-linear analysis. It aims to simulate the structural behaviour of various racking systems in the cross-aisle direction for the worst-case scenario, in order to quantify the vulnerability of chemical racks in seismic areas and to better understand the associated natech risk. Analytical fragility curves and a fault tree model were derived and used to evaluate the probabilities of chemical containers falling from racks. The damage state limits were considered as four levels of intensity of loss of containment. Three damage modes (overturning, sliding, and buckling), 2 types of chemical containers (205 l metal drums and 1000 l IBCs), 3 types of rack base anchoring (unanchored, anchored-brittle, and anchored-plastic), and four rack heights (3, 4.5, 6, 7.5, 9 m) were considered in the analysis. Overall, 24 fragility curves were developed based on 26 strong motion records from the PEER Strong Motion database. However, the analytical method employed in this study can also be used for deriving fragility curves for other merchandise types of racking structures. In order to assess the natech risk of a chemical rack containing a flammable substance, to test the developed fragility curves, and to illustrate the natech risk assessment and mapping capabilities of RAPID-N, a case study based on the 1786 Olivieri earthquake scenario was conducted. The findings demonstrate that chemical racks loaded with IBCs are more vulnerable than those loaded with drums and although a very robust anchorage reduces the probability of collapse of the rack, it increases the probability of chemical containers falling.

The paper discusses how to approach the problem of the social mitigation of seismic risk, in order to reduce damage and grief consequent to earthquakes. An alert protocol, intended as a working hypothesis, is proposed based on the experience gained from analysis of the be- haviour and social response to the threat before and after the great disaster of the L’Aquila earth- quake on 6th April 2009. Authors propose a protocol addressing four levels of increasing alert based on signs of earthquake preparation and social concerns. In this sense, it works as an intensity scale and does not strictly relate to earthquake size (magnitude) or seismic hazard. The proposed alert protocol provides sensible measures for reducing vulnerability, which is the only factor that can be more or less efficiently controlled, based on structural and behavioural adjustments. Factors indicating the difficult re- lationship between politicians, scientific com- munity and citizens are considered: 1) a serious gap between researchers and citizens; 2) meas- ures adopted by local administrators and the National Civil Protection Service not agreed by the population; 3) misunderstanding originated from a lack of clarity of communication about scientific terminology; and 4) the lack of an alert procedure protocol. In the current situation, all these problems are crucial and contribute to the unpreparedness to face a seismic event, and thus greatly increase the risk. The adoption and implementation of an alert procedure protocol requires a preliminary assessment of the con- text and should be adapted to the local sensibil- ity and culture. The application of a protocol may reduce the contrasts between preventive measures and individual responsibilities, mak-
ing mitigation measures more feasible and so- cially acceptable. In this paper, risk evaluation is not strictly related to probabilistic or determi- nistic predictions. In fact, this is a result of a project that comes from the general analysis of risk and is not intended to give an alternative hazard estimate method. This paper proposes an alert protocol addressing four levels of in- creasing alert based on signs of earthquake generating preparation and social concerns. Finally, there is a suggestion on how to gradu- ally communicate the threat and get citizens in- volved in the risk mitigation process.

Poster for the "Construire face au risque naturel dansles sociétés anciennes" Conference, Naples, 6-7 September 2019, Centre Jean Bérard Italian Abstract: Il 62 d.C. è l’anno che segna l’inizio di un periodo caratterizzato da una serie di terremoti che si manifestarono, con continuità, fino alla completa distruzione di Pompei causata dall’eruzione del Vesuvio del 79 d.C. Gli effetti della suddetta sequenza sismica e, successivamente, dei flussi piroclastici prodotti dall’eruzione, ancora oggi leggibili sui manufatti, costituiscono un repertorio di dati essenziali per ripercorrere la storia degli eventi che hanno caratterizzato l’edificato dell’antica città campana. La ricerca proposta si fonda proprio su queste evidenze, tentando di ricostruire da un lato la sequenza degli eventi sismici e la dinamica eruttiva, dall’altro l’intensità delle azioni esercitate sulle costruzioni da questi ultimi e le misure attuate dagli antichi pompeiani per rinforzare e mettere in sicurezza l’edificato danneggiato. L’approccio utilizzato è di tipo olistico, includendo nell’analisi, oltre alle tradizionali scienze storiche, elementi di meccanica dei materiali e di meccanica delle strutture. Presentato attraverso tre casi studio paradigmatici, le Terme Stabiane (VII, 1, 8), la Torre di Mercurio (torre XI) della cinta muraria nord e il colonnato del Foro civile, il contributo proposto si compone di una prima fase di reperimento dei dati archeologici esistenti in letteratura, di un dettagliato rilievo dei tagli, deformazioni e dislocazioni caratterizzanti tuttora i manufatti, seguita da annotazioni inerenti all’organizzazione dell’apparecchio murario e delle caratteristiche di forma. Tali dati, supportati dai risultati ottenuti attraverso codici di calcolo, alcuni dei quali sviluppati ad hoc per l’analisi di casi specifici, hanno consentito, in maniera poco usuale rispetto ai modelli predittivi di impiego comune nell’analisi delle strutture, di ripercorrere passo dopo passo il comportamento manifestato dai manufatti analizzati in occasione degli eventi sismici e durante l’eruzione di I secolo.

Se presenta una metodología de Análisis Beneficio Costo (ABC) en la mitigación del riesgo sísmico, con el objetivo de analizar la factibilidad de la ejecución de los proyectos. La metodología de ABC consiste en estimar los costos del refuerzo sismorresistente o remplazo de la edificación y los beneficios como pérdidas evitadas, a partir de caracterizar: 1) la amenaza sísmica como la probabilidad anual de excedencia de sismos; 2) la vulnerabilidad de cada edificación en términos de la pérdida media esperada dada la ocurrencia de un sismo; 3) el riesgo expresado en términos de pérdida anual esperada (PAE) desde el punto de vista económico debida a todos los sismos que pudiesen ocurrir en el sitio, y 4) la relación Beneficio/Costo dada por la diferencia entre la PAE en la edificación existente y la PAE luego de los obras de mitigación, dividida entre el costo de la obra y la tasa de descuento. Adicionalmente se determinan los beneficios sociales en término de vidas salvadas y víctimas evitadas dado el evento sísmico. Se aplica esta metodología a 10 edificaciones en Venezuela. El ABC indica que los beneficios obtenidos superan ampliamente los costos de la inversión requerida, con la excepción de un edificio. Adicionalmente la implementación de las medidas de mitigación logra proteger a las 8.098 personas expuestas y evitar pérdidas de vidas. PALABRAS CLAVE: análisis beneficio costo; mitigación del riesgo, refuerzo sismorresistente; vulnerabilidad estructural; pérdida anual esperada.

One of the key objectives of the new EU civil protection mechanism is an enhanced understanding of risks the EU is facing. Developing a European perspective may create significant opportunities of successfully combining resources for the common objective of preventing and mitigating shared risks. Risk assessments and mapping represent the first step in these preventive efforts. The EU is facing an increasing number of natural disasters. Among them earthquakes are the second deadliest after extreme temperatures. A better-shared understanding of where seismic risk lies in the EU is useful to identify which regions are most at risk and where more detailed seismic risk assessments are needed. In that scope, seismic risk assessment models at a pan-European level have a great potential in obtaining an overview of the expected human and economic losses using a homogeneous quantitative approach and harmonized datasets. This study strives to demonstrate the feasibility of performing a seismic risk assessment at a pan-European level with an open access methodology and using open datasets available across the EU. It also aims at highlighting the challenges and needs in datasets and the information gaps for a consistent assessment of seismic risk at the pan-European level. Results are expressed as expected casualties and economic losses for a return period of 475-year. The study constitutes a ''proof of concept'' that can complement the information provided by Member States in their National Risk Assessments. Its main contribution lies in pooling open-access data from different sources in a homogeneous format, which could serve as baseline data for performing more in depth risk assessments in Europe.

Over the years new coating design and technology for structures have received much attention mainly due to the demand for longer life span and durability. Conventional coating general consists of few homogeneous layers being deposited on the parent material or substrate. These layers are very vulnerable to cracking followed by de-bonding due to mismatch thermo-mechanical property. To avoid such coating failures, functionally graded material (FGM) is proposed in the coating design. Hence, this study analyzes FGM plates subjected to transverse load with clamped edges. Three configurations were considered. The first involves a two-layer plate in which a homogeneous coating layer was coated on a homogeneous substrate. The second involves a two layer system with the first layer as a FGM coating followed by the homogeneous substrate and the final configuration was a three layer system. The top and bottom layers are homogenous coating and substrates respectively, and the interlayer is composed of FGM. The Young's modulus of FGM plates is assumed to vary in the thickness direction based on the sigmoid functions and the Poisson's ratio remain constant throughout the FGM plate. The analysis was carried out in the context of two-dimensional elasticity theory and the method of superposition was used to find a series solution. The deflections, strains, and stresses were evaluated and the differences between the elastic behaviors of all three design configurations were investigated.

http://ac.els-cdn.com/S1359836812005975/1-s2.0-S1359836812005975-main.pdf?_tid=bdc4d316-e777-11e2-bed9-00000aab0f02&acdnat=1373251404_aef28c551293c961249fa40e35625a42

"In the immediate aftermath of the Haiti earthquake of 12 January 2010, a joint study for the estimation of damage to the building stock based on aerial images was carried out by UNITAR-UNOSAT, the EC-JRC, and the World Bank/ImageCAT in support of the PDNA. A targeted field campaign was led to the areas affected by the disaster in collaboration with the CNIGS with the purpose of validating the remote sensing based damage assessment. These two methodologies for collecting data resulted in two data sets of the damaged buildings categorized according to the EMS-98 damage grades. In the present study, fragility functions for different urban zones of Haiti, that is, low-, medium-, and high-density built-up and shanty zones, are developed from the remote sensing damage assessment data. Structural fragilities for buildings grouped with respect to material type and number of stories are derived on the basis of field damage data.
[DOI: 10.1193/1.4000189]"

This paper focuses on the evaluation of the effect of masonry-infilled walls on the seismic response of a four-storey RC school building. Numerical simulation is presented with respect to the building with and without masonry-infilled walls. The simulation employed force-based fibre elements for beams and columns, and a single equivalent diagonal strut to represent the masonry infill. The numerical model was verified through comparison with shake table test results. It was found that the presence of masonry-infilled walls has significant influence on the global response of the structure. Although the displacement of the structure with infilled wall is reduced in the in-plane direction, it was increased in both in-plane and out-of-plane directions when the infilled walls experienced loss in serviceability.

Link to Full-Text Articles :
http://link.springer.com/article/10.1007/s11069-015-1706-x

Seismic vulnerability assessment of masonry buildings is a fundamental issue even for moderate to low seismic hazard regions. This fact is even more important when dealing with old structures such as those located in Annaba city (Algeria), which the majority date back to the French colonial era from 1830. This category of buildings is in high risk due to their highly degradation state, heterogeneous materials and intrusive modifications to structural and non-structural elements. Furthermore, they are usually shelter a dense population, which is exposed to such risk. In order to undertake a suitable seismic risk mitigation strategies and reinforcement process for such structures, it is essential to estimate their seismic resistance capacity at a large scale. In this sense, two seismic vulnerability index methods and damage estimation have been adapted and applied to a pilot-scale building area located in the moderate seismic hazard region of Annaba city:  the first one based on the EMS-98 building typologies, and the second one derived from the Italian GNDT approach. To perform this task, the authors took the advantage of an existing data survey previously performed for other purposes. The results obtained from the application of the two methods were integrated and compared using a geographic information system tool (GIS), suggesting that the seismic vulnerability of buildings surveyed at Annaba city is high and therefore risk mitigation strategies should be implemented to minimize it.

Experimental observations on 11 RC columns tested at Nanyang Technological University and existing experimental data of 79 shear-critical RC columns are presented. Significant arch action is found in columns with a small shear span-to-depth ratio and high axialload ratio under shear force. Using the sectional method for shear strength of these types of columns, which does not consider arch action, would give a more conservative prediction. On the basis of the truss-arch model, an expression to predict the shear strength of shear-critical RC columns is presented, which considers both the contributions of concrete and transverse reinforcement to shear strength in the truss model, as well as the contribution of arch action through compatibility of deformation. The proposed model is compared with other shear strength models using the available column test data consisting of 90 shear-critical RC columns, and the results show that the proposed model can improve the accuracy of shear strength predictions for shear-critical RC columns.

The paper discusses the seismic assessment of Mallorca cathedral in Spain. This cathedral is an audacious Gothic structure built on the island of Mallorca during 14th-16th centuries, characterized by its large dimensions and slender structural members. For that purpose, different analysis methods were used. A 3D Finite Element (FE) model of the cathedral was created and then updated based on in-situ dynamic identification tests. Nonlinear static (pushover) analysis was firstly carried out applying the seismic loads in the longitudinal and transversal directions of the cathedral considering both positive and negative signs. The pushover results were compared with the results of the kinematic limit analysis as a way to cross check the seismic safety assessment. Although for such a large historical structure, the nonlinear time-history (dynamic) analysis requires a very high computer effort, an attempt to perform this type of advanced analysis was carried out. KEYWORDS: Seismic assessment, Mallorca cathedral, pushover analysis, non-linear dynamic analysis, limit analysis 42 A. ELYAMANI et al.