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1.
Christophe Martin Gabriele Ameri David Baumont David Carbon Gloria Senfaute Jean-Michel Thiry Ezio Faccioli Jean Savy 《Bulletin of Earthquake Engineering》2018,16(6):2477-2511
The accurate evaluation and appropriate treatment of uncertainties is of primary importance in modern probabilistic seismic hazard assessment (PSHA). One of the objectives of the SIGMA project was to establish a framework to improve knowledge and data on two target regions characterized by low-to-moderate seismic activity. In this paper, for South-Eastern France, we present the final PSHA performed within the SIGMA project. A new earthquake catalogue for France covering instrumental and historical periods was used for the calculation of the magnitude-frequency distributions. The hazard model incorporates area sources, smoothed seismicity and a 3D faults model. A set of recently developed ground motion prediction equations (GMPEs) from global and regional data, evaluated as adequately representing the ground motion characteristics in the region, was used to calculate the hazard. The magnitude-frequency distributions, maximum magnitude, faults slip rate and style-of-faulting are considered as additional source of epistemic uncertainties. The hazard results for generic rock condition (Vs30 = 800 m/s) are displayed for 20 sites in terms of uniform hazard spectra at two return periods (475 years and 10,000 years). The contributions of the epistemic uncertainties in the ground motion characterizations and in the seismic source characterization to the total hazard uncertainties are analyzed. Finally, we compare the results with existing models developed at national scale in the framework of the first generation of models supporting the Eurocode 8 enforcement, (MEDD 2002 and AFPS06) and at the European scale (within the SHARE project), highlighting significant discrepancies at short return periods. 相似文献
2.
A temporary accelerometer network has been installed in Tarcento (Friuli, NE Italy), a small town heavily hit by the 1976–1977
Friuli earthquake sequence, as a part of an ongoing research project aimed at ground motion simulation and generation of shakemaps
in the near-field of an earthquake. The network operated from October 2008 to April 2010 and consisted of three K2 accelerographs
with internal Episensor, distributed over a linear array of about 1.5 km length. Tarcento town had been chosen, at the end
of the 1970s, as the ideal site for a pilot microzonation study, the first of this kind in Italy, in which a substantial number
of field (and laboratory) tests were carried out in order to assess the mechanical properties of local alluvium deposits and
their complex (3D) geometrical configuration. The data from the temporary network, illustrated herein, allow for proper verification
and review of some of the quantitative predictions formulated in the 1980 study. As argued in the discussion section, we also
believe that the data are apt to provide valuable information of more general interest on the complex seismic response of
alluvium-filled valleys, and we show therein how the observations can be interpreted in the light of presently available parametric
simulation studies and simplified criteria for handling basin amplification effects. 相似文献
3.
Ezio Caroli Natalia Auricchio Lorenzo Amati Yuriy Bezsmolnyy Carl Budtz-JøRgensen Rui M. Curado da Silva Filippo Frontera Alessandro Pisa Stefano Del Sordo John B. Stephen Giulio Ventura 《Experimental Astronomy》2005,20(1-3):341-351
The energy range above 60 keV is important for the study of many open problems in high energy astrophysics such as the role of Inverse Compton with respect to synchrotron or thermal processes in GRBs, non thermal mechanisms in SNR, the study of the high energy cut-offs in AGN spectra, and the detection of nuclear and annihilation lines. Recently the development of high energy Laue lenses with broad energy bandpasses from 60 to 600keV have been proposed for a Hard X ray focusing Telescope (HAXTEL) in order to study the X-ray continuum of celestial sources. The required focal plane detector should have high detection efficiency over the entire operative range, a spatial resolution of about 1mm, an energy resolution of a few keV at 500keV and a sensitivity to linear polarization. We describe a possible configuration of the focal plane detector based on several CdTe/CZT pixelated layers stacked together to achieve the required detection efficiency at high energy.
Each layer can operate both as a separate position sensitive detector and polarimeter or work with other layers to increase the overall photopeak efficiency. Each layer has a hexagonal shape in order to minimize the detector surface required to cover the lens field of view. The pixels would have the same geometry so as to provide the best coupling with the lens point spread function and to increase the symmetry for polarimetric studies. 相似文献
4.
B. Borzi G. M. Calvi A. S. Elnashai E. Faccioli J. J. Bommer 《Soil Dynamics and Earthquake Engineering》2001,21(1):103
In recognition of the emergence of displacement-based seismic design as a potentially more rational approach than force-based techniques, this paper addresses derivation of inelastic displacement spectra and associated topics. A well-constrained earthquake strong-motion dataset is used to derive inelastic displacement spectra, displacement reduction factors and ductility–damping relationships. These are in a format amenable for use in design and assessment of structures with a wide range of response characteristics. 相似文献
5.
Ezio Faccioli 《Bulletin of Earthquake Engineering》2006,4(4):341-364
The main features of the Risk-UE project approach to assessing the ground-shaking (and related hazards) distribution within urban areas are described, as a basis for developing seismic damage scenarios for European cities. Emphasis was placed in the project on adoption of homogeneous criteria in the quantitative treatment of seismicity and in constructing the ground-shaking scenarios, despite wide differences in amount and quality of data available for the cities involved. The initial steps of the approach include treatment of the regional seismotectonic setting and the geotechnical zonation of the urban area, while the hazard assessment itself takes the form of both a deterministic analysis, and of a probabilistic, constant-hazard spectra analysis. Systematic 1D site response analyses were used, mostly in the softer soil zones, to modify (when needed) the obtained ground motion maps. Earthquake induced hazard effects, such as liquefaction and landsliding, are also briefly dealt with at the end. 相似文献
6.
Valentina?MontaldoEmail author Ezio?Faccioli Gaetano?Zonno Aybige?Akinci Luca?Malagnini 《Journal of Seismology》2005,9(3):295-316
In the framework of the 2004 reference seismic hazard map of Italy the amplitude of the strong-motion (expressed in terms
of Peak Horizontal Acceleration with 10% probability of non-exceedence in 50 years, referred to average hard ground conditions)
was computed using different predictive relationships. Equations derived in Italy and in Europe from strong-motion data, as
well as a set of weak and strong-motion based empirical predictive relationships were employed in a logic tree procedure,
in order to capture the epistemic uncertainty affecting ground-motion attenuation. This article describes the adjustments
and conversions required to eliminate the incompatibilities amongst the relations. Particularly significant are distance conversions
and style-of-faulting adjustments, as well as the problems related to the use of regional relations, such as the selection
of a reference depth, the quantification of random variability and the strong-motion prediction. Moreover, a regional attenuation
relationship specific for volcanic areas was also employed, allowing a more realistic evaluation of seismic hazard, as confirmed
by the attenuation of macroseismic intensities. 相似文献
7.
Complex site effects and building codes: Making the leap 总被引：1，自引：0，他引：1
The engineering community is aware of the importance of site effects, but it lags behind seismological studies when it comes to incorporating site effect considerations in design spectra for seismic norms. This lag is reflected in the conspicuous fact that current building codes make allowance for 1D site effects but ignore complex site effects. The purpose of this paper is to explore a way for including complex site effects in a building code environment. We take as example Eurocode 8, which is a modern code that exemplifies the current approach to site effect consideration. We examine the restrictions that we have imposed to make the problem of a feasible size and discuss the approach we have taken. We propose a strategy to incorporate a class of complex site effects in a design elastic spectrum. 相似文献
8.
A systematic analysis was conducted of the different variability components that affect the prediction of $\text{ log }_{10}(PSA)$ (i.e., Pseudo-Spectral Acceleration) ordinates on (mostly) deep sedimentary soil sites using a sizable set of strong motion data recorded in the strong earthquake sequences of 2010 and 2012 in the Canterbury region of New Zealand. Following recent, well established approaches of residual analysis of ground motion predictions, as well as recent GMPEs based on a global dataset, it was found that the event-corrected single-station standard deviation (“sigma”) is strongly decreased, for all selected stations, with respect to the uncorrected sigma. Likewise, the event-corrected intraevent sigma estimated for the entire dataset is significantly reduced compared to the standard deviation associated to ground motion prediction models, i.e. the “ergodic” sigma, for all spectral periods. The event-corrected sigma values for the present dataset are surprisingly consistent with those recently derived using KiK-Net strong motion data from Japan and those by Boore and Atkinson (Earthq Spectra 34(1):99–138, 2008) GMPE, and remain fairly constant with respect to the spectral period at about $0.15\sim 0.2$ . An interpretation was provided of the physical meaning of the site correction term ( ${\delta }S2S)_{s}$ indicating a plausible correlation with prevailing geological conditions in the site area. 相似文献
9.
Dynamic Characterization of Orthogneiss Rock Subjected to Intermediate and High Strain Rates in Tension 总被引：4，自引：3，他引：1
Ezio Cadoni 《Rock Mechanics and Rock Engineering》2010,43(6):667-676
The dynamic characterization of rocks under intermediate and high strain rates is fundamental to understand the material behavior in case of heavy earthquakes and dynamic events. The implementation of material constitutive laws is of capital importance for the numerical simulation of the dynamic processes as those caused by earthquakes. These data are necessary and require experimental techniques able to induce on the rock materials state of loading reproducing the actual dynamic condition. The dynamic characterization has been carried out by means of two special apparatus: the split Hopkinson tension bar and the hydro-pneumatic machine. These equipments are briefly described with a discussion on the results of dynamic tension tests at three different strain rates (0.1, 10, 100 strain/s) on Onsernone Orthogneiss for loading directions 0°, 45° and 90° with respect to the schistosity. Results of the tests show a significant strain rate sensitive behavior, exhibiting dynamic tensile strength increasing with strain rate, up to about two times with respect to the quasi-static conditions in the case of 0° and 45° orientation and more than three times in the case of 90° at high strain rates. Dynamic increase factors versus strain rate curves for tensile strength were also evaluated and discussed. 相似文献
10.
Eva Pacioni Marco Petitta Ezio Burri Maria Fanelli Piero Mazzeo Fabrizio Ruggieri 《Environmental Earth Sciences》2010,61(1):201-216
This paper analyses flow and transport of pesticides from the unsaturated zone to groundwater so as to predict concentration
of those contaminants in the Fucino Plain’s groundwater, by site investigations and numerical simulations. Pesticides were
detected in surface water (peaks of 13 μg L−1) and groundwater (peaks of 0.37 μg L−1). Modelling tools made it possible to identify that pattern of precipitation, organic matter content, and root thickness
are the key factors involved in vertical seepage of pesticides. Numerical simulations indicated that a significant fraction
of contaminants is leached from the most surficial soil layers through runoff, while only a secondary fraction is mobilised
towards groundwater. Likelihood of contaminating deep groundwater is fairly low, whereas surface waters show higher susceptibility.
Results of the proposed conceptual hydrogeological model show that pesticides are more likely to be entrained by mixing of
stream water with shallow groundwater in periods of high water exploitation from shallow wells. 相似文献