In this article the recently proposed approach known as 'risk-targeting' for the development of national seismic design maps is investigated for mainland France. Risktargeting leads to ground-motion maps that, if used for design purposes, would lead to a uniform level of risk nationally. The Eurocode 8 design loads currently in force for France are used as the basis of this study. Because risk-targeting requires various choices on, for example, the level of acceptable risk to be made a priori and these choices are not solely engineering decisions but involve input from decision makers we undertake sensitivity tests to study their influence. It is found that, in contrast to applications of this methodology for US cities, risk-targeting does not lead to large modifications with respect to the national seismic hazard map nor to changes in the relative ranking of cities with respect to their design ground motions. This is because the hazard curves for French cities are almost parallel. In addition, we find that using a target annual collapse probability of about 10 −5 for seismically-designed buildings and a probability of collapse when subjected to the design PGA of 10 −5 leads to reasonable results. This is again in contrast to US studies that have adopted much higher values for both these probabilities.

38The focus of this study is an analysis of building vulnerability through investigating impacts 45This study assesses the aspects of building design and site specific environmental hazard proxy in areas where more detailed hydrodynamic modeling data is not available. 50Building design and site-specific environmental conditions determine the physical vulnerability. 51The mathematical approach considers both physical vulnerability and hazard related 52 parameters and helps to reduce uncertainty in the determination of descriptive parameters, 53parameter interdependency and respective contributions to damage. This study aims to (1) 54 enable the estimation of damage probability for a certain hazard intensity, and (2) obtain data 67show that 90% of these tests have a success rate of more than 67%. Probabilities (at building 882011; Thouret et al., 2013Thouret et al., , 2014, and apparent locally high vulnerability of buildings and 89 critical infrastructure in Arequipa, are major motivations for this study. 90Risk in the context of disaster risk management is commonly defined as a potential loss for a 91 given probability function (Crichton, 1999; Kaplan and Garrick, 1981). In the standard 92 conceptual framework, risk is the product of hazard, vulnerability and exposure (Cardona, 93 2004; Carreno et al., 2006). While the hazard is generally described by its severity, e.g. 94inundation height for a given return return period, exposure relates to the number and value of 95 elements potentially affected (Hiete and Merz, 2009). Many different definitions, concepts and 96 methods to systemize vulnerability exist in the current literature (Birkmann, 2006; Cutter, 2003; 97 Wisner et al., 2004; Thywissen, 2006; IPCC, 2007; Bründl et al., 2009). In this study we follow 98 the definition for physical vulnerability proposed by Glade (2003) and Villagran de Leon (2006) 99 as the predisposition of an element or system to be affected or susceptible to damage as the 100 result of the natural hazard's impact. Vulnerability assessment for hydro-geomorphic hazards conducted to study and record structural damage following a hazard event, these data are then 112 generally correlated to the process intensity, frequently derived from deposition height or 113 inundation height, in order to develop empirical fragility curves (Fuchs et al., 2007a,b; Holub 114 and Fuchs, 2008 133Flash floods are common in semi-arid areas, such as Arequipa, and can, despite their 134 infrequent nature, have a devastating effect in both geomorphological and human terms 135 (Gaume et al., 2009; Jonkman and Vrijling, 2008;Martínez Ibarra, 2012). The occurrence of 136 flash floods is highly variable, both spatially and temporally, most occurring as the result of 137 localized intense storms (Graf, 1988;Reid and Frostick, 1992; Hooke and Mant, 2000 , 2007a,b; Holub and Fuchs, 2008). 160Several recent studies (Martelli, 2011;Santoni, 2011; Ettinger et al., 2014a,b; Thouret et al., 161 2013 Thouret et al., 161 , 2014 192On 8...

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Seismic design using maps based on "risk-targeting" would lead to an annual probability of attaining or exceeding a certain damage state that is uniform over an entire territory. These maps are based on convolving seismic hazard curves from a standard probabilistic analysis with the derivative of fragility curves expressing the chance for a code-designed structure to attain or exceed a certain damage state given a level of input motion, e.g. peak ground acceleration (PGA). There are few published fragility curves for structures respecting the Eurocodes (ECs, principally EC8 for seismic design) that can be used for the development of risk-targeted design maps for Europe. In this article a set of fragility curves for a regular three-storey reinforced-concrete building designed using EC2 and EC8 for medium ductility and increasing levels of design acceleration (ag) is developed. These curves show that structures designed using EC8 against PGAs up to about 1 m/s2 have similar fragilities to those that respect only EC2 (although this conclusion may not hold for irregular buildings, other geometries or materials). From these curves, the probability of yielding for a structure subjected to a PGA equal to ag varies between 0.14 (ag =0.7m/s2) and 0.85 (ag=3m/s2 whereas the probability of collapse for a structure subjected to a PGA equal to ag varies between 1.7×10-7(ag=0.7 m/s2) and 1.0 × 10-5 (ag=3m/s2)

Over recent years, many studies devoted to large-scale seismic risk analyses have been carried out in different regions and by various research teams. A wide variety of software is available to perform these analyses: they are more or less flexible and use different levels of precision to model ground motion and vulnerability of the built environment. All are based on risk calculation through the convolution of hazard and vulnerability. This paper presents a seismic risk analysis tool, Armagedom, implemented over the past five years on a variety of urban seismic contexts: Bouzareah (Algeria), four provinces in Iran, the French Departments lying along the French/Spanish border and Overseas Departments in the French Antilles. The objectives and requirements of these studies differed with respect to the level of precision that was sought and the surface areas examined. In 2 O. Sedan, C. Negulescu, M. Terrier, A. Roullé, Th. Winter, D. Bertil order to meet differing project targets, three levels of seismic risk assessment were defined based on the macroseismic and mechanical approaches for vulnerability and damage estimation presenting different levels of precision: Level N0 estimates seismic risk on a regional territorial scale based on the macroseismic approach and existing statistical data; Level N1 yields the seismic risk at a district level based on the macroseismic approach and on visual evaluation of the vulnerability of structures over an itinerary in the area to be analyzed; and Level N2 also establishes the seismic risk at a district level, but the hazard description is represented by a spectrum and vulnerability is estimated based on mechanical models. The software, with a modular design, was developed in order to optimize computation time and to automate execution of the three levels of analysis. In this paper, the software modules are illustrated by maps derived from the seismic risk analyses performed. We further use the available event information to test, validate and update the methods and the software presented in this paper.

Abstract. The aim of this paper is to propose a simplified methodology to evaluate the mechanical performances of buildings exposed to landslide hazard, by using procedures inspired from the seismic risk analysis, such as the Capacity Spectrum Method (ATC 40, 1996). Landslide hazard involves so many aspects, that quantitative vulnerability assessment requires to consider one basic scenario at a time, i.e. one typology for the landslide hazard and one for the structural element considered. In this paper, we propose to assess vulnerability for simple one bay-one storey reinforced concrete (RC) frame structures subjected to differential settlements, using 2-D parametric nonlinear static time-history analyses. After a short review of methods used in practice to estimate building deformations induced by ground movements (e.g. differential settlements), we present the parametric studies carried out to identify the most relevant parameters, in order to predict the structural damage, as well as the methodology to develop analytical fragility curves, that can be used to quantitatively evaluate the structural vulnerability in landslide risk analyses. Different types of parameters that could influence structural behaviour have been examined in this analysis: foundation type (i.e. different combinations of links), cross-section geometry, section reinforcement degree, displacement magnitudes and displacement inclination angles. We show that the magnitude and inclination angle of displacements can be used as two relevant parameters for this type of landslide scenario. Based on these results, some simulations are conducted using the software SeismoStruct (SeismoSoft, 2003), and the proposed structural damage levels consider the local strain limits of steel and concrete constitutive materials. Some preliminary fragility curves are proposed with respect to the magnitude of differential ground displacement. It can be seen that the curves correspondCorrespondence to: C. Negulescu (c.negulescu@brgm.fr) ing to limit states LS2 (moderate damage) and LS4 (complete damage) in the present study, correspond respectively to the "tolerable settlements" "observed intolerable settlements" curves proposed by Zhang and Ng (2005).

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This article studies the effects of the soil data and exposure data of residential building inventories, as well as their spatial resolution, on seismic damage and loss estimates for a given earthquake scenario. Our aim is to investigate how beneficial it would be to acquire higher resolution inventories at the cost of additional effort and resources. Seismic damage computations are used to evaluate the relative influence of varying spatial resolution on a given damage model, where other parameters were held constant. We use soil characterization maps and building exposure inventories, provided at different scales from different sources: the European database, a national dataset at the municipality scale, and local field investigations. Soil characteristics are used to evaluate site effects and to assign amplification factors to the strong motion applied to the exposed areas. Exposure datasets are used to assign vulnerability indices to sets of buildings, from which a damage distribution is produced (based on the applied seismic intensity). The different spatial resolutions are benchmarked in a case-study area which is subject to moderate-to-average seismicity levels (Luchon valley in the Pyrénées, France). It was found that the proportion of heavily damaged buildings is underestimated when using the European soil map and the European building database, while the more refined databases (national/regional vs. local maps) result in similar estimates for moderate earthquake scenarios. Finally, we highlight the importance of pooling open access data from different sources, but caution the challenges of combining different datasets, especially depending on the type of application that is pursued (e.g., for risk mitigation or rapid response tools).