TY - JOUR A1 - Derras, Boumediene A1 - Bard, Pierre-Yves A1 - Cotton, Fabrice Pierre T1 - V-S30, slope, H-800 and f(0): performance of various site-condition proxies in reducing ground-motion aleatory variability and predicting nonlinear site response JF - Earth, planets and space N2 - The aim of this paper is to investigate the ability of various site-condition proxies (SCPs) to reduce ground-motion aleatory variability and evaluate how SCPs capture nonlinearity site effects. The SCPs used here are time-averaged shear-wave velocity in the top 30 m (V-S30), the topographical slope (slope), the fundamental resonance frequency (f(0)) and the depth beyond which V-s exceeds 800 m/s (H800). We considered first the performance of each SCP taken alone and then the combined performance of the 6 SCP pairs [V-S30-f(0)], [V-S30-H-800], [f(0)-slope], [H-800-slope], [V-S30-slope] and [f(0)-H-800]. This analysis is performed using a neural network approach including a random effect applied on a KiK-net subset for derivation of ground-motion prediction equations setting the relationship between various ground-motion parameters such as peak ground acceleration, peak ground velocity and pseudo-spectral acceleration PSA (T), and Mw, RJB, focal depth and SCPs. While the choice of SCP is found to have almost no impact on the median groundmotion prediction, it does impact the level of aleatory uncertainty. VS30 is found to perform the best of single proxies at short periods (T < 0.6 s), while f(0) and H-800 perform better at longer periods; considering SCP pairs leads to significant improvements, with particular emphasis on [V-S30-H-800] and [f(0)-slope] pairs. The results also indicate significant nonlinearity on the site terms for soft sites and that the most relevant loading parameter for characterising nonlinear site response is the "stiff" spectral ordinate at the considered period. KW - Aleatory variability KW - Site-condition proxies KW - KiK-net KW - Neural networks KW - GMPE KW - Nonlinear site response Y1 - 2017 U6 - https://doi.org/10.1186/s40623-017-0718-z SN - 1880-5981 VL - 69 SP - 1623 EP - 1629 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Bommer, Julian J. A1 - Abrahamson, Norman A. A1 - Strasser, F. O. A1 - Pecker, Alain A1 - Bard, Pierre-Yves A1 - Bungum, Hilmar A1 - Cotton, Fabrice Pierre A1 - Fäh, Donat A1 - Sabetta, F. A1 - Scherbaum, Frank A1 - Studer, Jost T1 - The challenge of defining upper bounds on earthquake ground motions Y1 - 2004 SN - 0895-0695 ER - TY - GEN A1 - Derras, Boumédiène A1 - Bard, Pierre-Yves A1 - Cotton, Fabrice Pierre T1 - VS30, slope, H800 and f0 BT - performance of various site-condition proxies in reducing ground-motion aleatory variability and predicting nonlinear site response T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - The aim of this paper is to investigate the ability of various site-condition proxies (SCPs) to reduce ground-motion aleatory variability and evaluate how SCPs capture nonlinearity site effects. The SCPs used here are time-averaged shear-wave velocity in the top 30 m (VS30), the topographical slope (slope), the fundamental resonance frequency (f0) and the depth beyond which Vs exceeds 800 m/s (H800). We considered first the performance of each SCP taken alone and then the combined performance of the 6 SCP pairs [VS30–f0], [VS30–H800], [f0–slope], [H800–slope], [VS30–slope] and [f0–H800]. This analysis is performed using a neural network approach including a random effect applied on a KiK-net subset for derivation of ground-motion prediction equations setting the relationship between various ground-motion parameters such as peak ground acceleration, peak ground velocity and pseudo-spectral acceleration PSA (T), and Mw, RJB, focal depth and SCPs. While the choice of SCP is found to have almost no impact on the median groundmotion prediction, it does impact the level of aleatory uncertainty. VS30 is found to perform the best of single proxies at short periods (T < 0.6 s), while f0 and H800 perform better at longer periods; considering SCP pairs leads to significant improvements, with particular emphasis on [VS30–H800] and [f0–slope] pairs. The results also indicate significant nonlinearity on the site terms for soft sites and that the most relevant loading parameter for characterising nonlinear site response is the “stiff” spectral ordinate at the considered period. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 817 KW - aleatory variability KW - site-condition proxies KW - KiK-net KW - neural networks KW - GMPE KW - nonlinear site response Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427071 SN - 1866-8372 IS - 817 ER - TY - JOUR A1 - Di Giulio, Giuseppe A1 - Savvaidis, Alexandros A1 - Ohrnberger, Matthias A1 - Wathelet, Marc A1 - Cornou, Cecile A1 - Knapmeyer-Endrun, Brigitte A1 - Renalier, Florence A1 - Theodoulidis, Nikos A1 - Bard, Pierre-Yves T1 - Exploring the model space and ranking a best class of models in surface-wave dispersion inversion application at European strong-motion sites JF - Geophysics N2 - The inversion of surface-wave dispersion curve to derive shear-wave velocity profile is a very delicate process dealing with a nonunique problem, which is strongly dependent on the model space parameterization. When independent and reliable information is not available, the selection of most representative models within the ensemble produced. by the inversion is often difficult. We implemented a strategy in the inversion of dispersion curves able to investigate the influence of the parameterization of the model space and to select a "best" class of models. We analyzed surface-wave dispersion curves measured at 14 European strong..-motion sites within the NERIES EC-Project. We focused on the inversion task exploring the model space by means of four distinct pararneterization classes composed of layers progressively added over a half-space. The classes differ in the definition of the shear-wave velocity profile; we considered models with uniform velocity as well as models with increasing velocity with depth. At each site and for each model parameterization, we performed an extensive surface-wave inversion (200,100 models for five seeds) using the conditional neighborhood algorithm. We addressed the model evaluation following the corrected Akaike's information criterion (AlCc) that combines the concept of misfit to the number of degrees of freedom of the system. The misfit was computed as least-squares estimation between theoretical and observed dispersion curve. The model complexity was accounted in a penalty term by AlCc. By applying such inversion strategy on 14 strong-motion sites, we found that the best parameterization of the model space is mostly three to four layers over a half-space: where the shear-wave velocity of the uppermost layers can follow uniform or power-law dependence with depth. The shear-wave velocity profiles derived by inversion agree with shear-wave velocity profiles provided by borehole surveys at approximately 80% of the sites. Y1 - 2012 U6 - https://doi.org/10.1190/GEO2011-0116.1 SN - 0016-8033 VL - 77 IS - 3 SP - B147 EP - B166 PB - Society of Exploration Geophysicists CY - Tulsa ER - TY - JOUR A1 - Douglas, John A1 - Akkar, Sinan A1 - Ameri, Gabriele A1 - Bard, Pierre-Yves A1 - Bindi, Dino A1 - Bommer, Julian J. A1 - Bora, Sanjay Singh A1 - Cotton, Fabrice Pierre A1 - Derras, Boumediene A1 - Hermkes, Marcel A1 - Kuehn, Nicolas Martin A1 - Luzi, Lucia A1 - Massa, Marco A1 - Pacor, Francesca A1 - Riggelsen, Carsten A1 - Sandikkaya, M. Abdullah A1 - Scherbaum, Frank A1 - Stafford, Peter J. A1 - Traversa, Paola T1 - Comparisons among the five ground-motion models developed using RESORCE for the prediction of response spectral accelerations due to earthquakes in Europe and the Middle East JF - Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering N2 - This article presents comparisons among the five ground-motion models described in other articles within this special issue, in terms of data selection criteria, characteristics of the models and predicted peak ground and response spectral accelerations. Comparisons are also made with predictions from the Next Generation Attenuation (NGA) models to which the models presented here have similarities (e.g. a common master database has been used) but also differences (e.g. some models in this issue are nonparametric). As a result of the differing data selection criteria and derivation techniques the predicted median ground motions show considerable differences (up to a factor of two for certain scenarios), particularly for magnitudes and distances close to or beyond the range of the available observations. The predicted influence of style-of-faulting shows much variation among models whereas site amplification factors are more similar, with peak amplification at around 1s. These differences are greater than those among predictions from the NGA models. The models for aleatory variability (sigma), however, are similar and suggest that ground-motion variability from this region is slightly higher than that predicted by the NGA models, based primarily on data from California and Taiwan. KW - Strong-motion data KW - Ground-motion models KW - Ground-motion prediction equations KW - Style of faulting KW - Site amplification KW - Aleatory variability KW - Epistemic uncertainty KW - Europe KW - Middle East Y1 - 2014 U6 - https://doi.org/10.1007/s10518-013-9522-8 SN - 1570-761X SN - 1573-1456 VL - 12 IS - 1 SP - 341 EP - 358 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Hobiger, M. A1 - Cornou, C. A1 - Wathelet, M. A1 - Di Giulio, G. A1 - Knapmeyer-Endrun, B. A1 - Renalier, F. A1 - Bard, Pierre-Yves A1 - Savvaidis, Alexandros A1 - Hailemikael, S. A1 - Le Bihan, N. A1 - Ohrnberger, Matthias A1 - Theodoulidis, N. T1 - Ground structure imaging by inversions of Rayleigh wave ellipticity sensitivity analysis and application to European strong-motion sites JF - Geophysical journal international N2 - The knowledge of the local soil structure is important for the assessment of seismic hazards. A widespread, but time-consuming technique to retrieve the parameters of the local underground is the drilling of boreholes. Another way to obtain the shear wave velocity profile at a given location is the inversion of surface wave dispersion curves. To ensure a good resolution for both superficial and deeper layers, the used dispersion curves need to cover a wide frequency range. This wide frequency range can be obtained using several arrays of seismic sensors or a single array comprising a large number of sensors. Consequently, these measurements are time-consuming. A simpler alternative is provided by the use of the ellipticity of Rayleigh waves. The frequency dependence of the ellipticity is tightly linked to the shear wave velocity profile. Furthermore, it can be measured using a single seismic sensor. As soil structures obtained by scaling of a given model exhibit the same ellipticity curve, any inversion of the ellipticity curve alone will be ambiguous. Therefore, additional measurements which fix the absolute value of the shear wave velocity profile at some points have to be included in the inversion process. Small-scale spatial autocorrelation measurements or MASW measurements can provide the needed data. Using a theoretical soil structure, we show which parts of the ellipticity curve have to be included in the inversion process to get a reliable result and which parts can be omitted. Furthermore, the use of autocorrelation or high-frequency dispersion curves will be highlighted. The resulting guidelines for inversions including ellipticity data are then applied to real data measurements collected at 14 different sites during the European NERIES project. It is found that the results are in good agreement with dispersion curve measurements. Furthermore, the method can help in identifying the mode of Rayleigh waves in dispersion curve measurements. KW - Inverse theory KW - Surface waves and free oscillations KW - Site effects KW - Computational seismology KW - Wave propagation Y1 - 2013 U6 - https://doi.org/10.1093/gji/ggs005 SN - 0956-540X VL - 192 IS - 1 SP - 207 EP - 229 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Garofalo, F. A1 - Foti, S. A1 - Hollender, F. A1 - Bard, Pierre-Yves A1 - Cornou, C. A1 - Cox, B. R. A1 - Ohrnberger, Matthias A1 - Sicilia, D. A1 - Asten, M. A1 - Di Giulio, G. A1 - Forbriger, T. A1 - Guillier, B. A1 - Hayashi, K. A1 - Martin, A. A1 - Matsushima, Satoru A1 - Mercerat, D. A1 - Poggi, V. A1 - Yamanaka, H. T1 - InterPACIFIC project: Comparison of invasive and non-invasive methods for seismic site characterization. Part I: Intra-comparison of surface wave methods JF - Soil Dynamics and Earthquake Engineering N2 - The main scope of the InterPACIFIC (Intercomparison of methods for site parameter and velocity profile characterization) project is to assess the reliability of in-hole and surface-wave methods, used for estimating shear wave velocity. Three test-sites with different subsurface conditions were chosen: a soft soil, a stiff soil and a rock outcrop. This paper reports the surface-wave methods results. Specifically 14 teams of expert users analysed the same experimental surface-wave datasets, consisting of both passive and active data. Each team adopted their own strategy to retrieve the dispersion curve and the shear-wave velocity profile at each site. Despite different approaches, the dispersion curves are quite in agreement with each other. Conversely, the shear-wave velocity profiles show a certain variability that increases in correspondence of major stratigraphic interfaces. This larger variability is mainly due to non-uniqueness of the solution and lateral variability. As expected, the observed variability in V-s,V-30 estimatesis small, as solution non-uniqueness plays a limited role. (C) 2015 Elsevier Ltd. All rights reserved. KW - Surface-wave methods KW - Dispersion curve KW - Inversion KW - V-s,V-30 KW - Site characterization KW - MASW KW - Microtremors KW - Rayleigh waves KW - Geophysical methods Y1 - 2016 U6 - https://doi.org/10.1016/j.soildyn.2015.12.010 SN - 0267-7261 SN - 1879-341X VL - 82 SP - 222 EP - 240 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Derras, Boumediene A1 - Bard, Pierre-Yves A1 - Cotton, Fabrice Pierre T1 - Site-Condition Proxies, Ground Motion Variability, and Data-Driven GMPEs: Insights from the NGA-West2 and RESORCE Data Sets JF - Earthquake spectra : the professional journal of the Earthquake Engineering Research Institute N2 - We compare the ability of various site-condition proxies (SCPs) to reduce the aleatory variability of ground motion prediction equations (GMPEs). Three SCPs (measured V-S30, inferred V-S30, local topographic slope) and two accelerometric databases (RESORCE and NGA-West2) are considered. An artificial neural network (ANN) approach including a random-effect procedure is used to derive GMPEs setting the relationship between peak ground acceleration (PGA), peak ground velocity (PGV), pseudo-spectral acceleration [PSA(T)], and explanatory variables (M-w, R-JB, and V-S30 or Slope). The analysis is performed using both discrete site classes and continuous proxy values. All "non-measured" SCPs exhibit a rather poor performance in reducing aleatory variability, compared to the better performance of measured V-S30. A new, fully data-driven GMPE based on the NGA-West2 is then derived, with an aleatory variability value depending on the quality of the SCP. It proves very consistent with previous GMPEs built on the same data set. Measuring V-S30 allows for benefit from an aleatory variability reduction up to 15%. Y1 - 2016 U6 - https://doi.org/10.1193/060215EQS082M SN - 8755-2930 SN - 1944-8201 VL - 32 SP - 2027 EP - 2056 PB - Earthquake Engineering Research Institute CY - Oakland ER - TY - JOUR A1 - Foti, Sebastiano A1 - Hollender, Fabrice A1 - Garofalo, Flora A1 - Albarello, Dario A1 - Asten, Michael A1 - Bard, Pierre-Yves A1 - Comina, Cesare A1 - Cornou, Cecile A1 - Cox, Brady A1 - Di Giulio, Giuseppe A1 - Forbriger, Thomas A1 - Hayashi, Koichi A1 - Lunedei, Enrico A1 - Martin, Antony A1 - Mercerat, Diego A1 - Ohrnberger, Matthias A1 - Poggi, Valerio A1 - Renalier, Florence A1 - Sicilia, Deborah A1 - Socco, Valentina T1 - Guidelines for the good practice of surface wave analysis BT - a product of the InterPACIFIC project JF - Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering N2 - Surface wave methods gained in the past decades a primary role in many seismic projects. Specifically, they are often used to retrieve a 1D shear wave velocity model or to estimate the V-s,V-30 at a site. The complexity of the interpretation process and the variety of possible approaches to surface wave analysis make it very hard to set a fixed standard to assure quality and reliability of the results. The present guidelines provide practical information on the acquisition and analysis of surface wave data by giving some basic principles and specific suggestions related to the most common situations. They are primarily targeted to non-expert users approaching surface wave testing, but can be useful to specialists in the field as a general reference. The guidelines are based on the experience gained within the InterPACIFIC project and on the expertise of the participants in acquisition and analysis of surface wave data. KW - Rayleigh waves KW - MASW KW - Ambient vibration analysis KW - Site characterization KW - Shear wave velocity KW - V-S,V-30 Y1 - 2017 U6 - https://doi.org/10.1007/s10518-017-0206-7 SN - 1570-761X SN - 1573-1456 VL - 16 IS - 6 SP - 2367 EP - 2420 PB - Springer CY - Dordrecht ER -