Documents disponibles écrits par cet auteur

Examination and reevalaution of SPT-based liquefaction triggering case histories / Ross W. Boulanger in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 8 (Août 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 8 (Août 2012) . - pp. 898–909 Titre : Examination and reevalaution of SPT-based liquefaction triggering case histories Type de document : texte imprimé Auteurs : Ross W. Boulanger, Auteur ; Daniel W. Wilson, Auteur ; I.M. Idriss, Auteur Année de publication : 2012 Article en page(s) : pp. 898–909 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Liquefaction  Earthquakes  Cyclic  loads  Standard  penetration  test Résumé : A standard penetration test (SPT)-based liquefaction case history database for liquefaction triggering criteria is reexamined and reevaluated. The updated database incorporates a number of additional case histories, replaces prior estimates of earthquake magnitudes with current estimates of their moment magnitudes, uses improved estimates of peak ground accelerations when available, and includes a reexamination of the selection and computation of representative SPT (N1)60 values for most case histories. The approach used to select and compute representative SPT (N1)60cs values is illustrated using select case histories. The distribution of the case history data relative to the Idriss-Boulanger triggering correlation is examined for any bias with respect to various parameters and to identify the conditions that are, and are not, well covered by available case history data. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000668 [article] Examination and reevalaution of SPT-based liquefaction triggering case histories [texte imprimé] / Ross W. Boulanger, Auteur ; Daniel W. Wilson, Auteur ; I.M. Idriss, Auteur . - 2012 . - pp. 898–909. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 8 (Août 2012) . - pp. 898–909 Mots-clés : Liquefaction  Earthquakes  Cyclic  loads  Standard  penetration  test Résumé : A standard penetration test (SPT)-based liquefaction case history database for liquefaction triggering criteria is reexamined and reevaluated. The updated database incorporates a number of additional case histories, replaces prior estimates of earthquake magnitudes with current estimates of their moment magnitudes, uses improved estimates of peak ground accelerations when available, and includes a reexamination of the selection and computation of representative SPT (N1)60 values for most case histories. The approach used to select and compute representative SPT (N1)60cs values is illustrated using select case histories. The distribution of the case history data relative to the Idriss-Boulanger triggering correlation is examined for any bias with respect to various parameters and to identify the conditions that are, and are not, well covered by available case history data. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000668

Fast stacking and phase corrections of shear wave signals in a noisy environment / Scott J. Brandenberg in Journal of geotechnical and geoenvironmental engineering, Vol. 134 n°8 (Août 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 n°8 (Août 2008) . - pp. 1154–1165 Titre : Fast stacking and phase corrections of shear wave signals in a noisy environment Type de document : texte imprimé Auteurs : Scott J. Brandenberg, Auteur ; Kutter, Bruce L., Auteur ; Daniel W. Wilson, Auteur Année de publication : 2008 Article en page(s) : pp. 1154–1165 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Wave  velocity  Shear  waves  Soil  modulus  Soil-structure  interaction  Centrifuge  Piezoelectricity Résumé : Hardware, software, and analysis of transient response of sources and receivers are presented for a piezoelectric bender element system designed to measure shear wave velocities in noisy environments. Signal-to-noise ratio is improved by signal stacking, wherein data vectors from many pulses are summed. A new fast-stacking algorithm enables signal quality to be improved much more rapidly than conventional stacking. Conventional stacking is accomplished by repeatedly sending an excitation pulse to a source, waiting for the signal and secondary reflections to pass the receiver and then introducing a subsequent excitation pulse. Using conventional stacking, it is important to wait for the signal and secondary reflections to die out before exciting subsequent pulses. In the new fast-stacking algorithm, a varied interval between consecutive pulses is used so that high quality signals can be obtained even if consecutive pulses are excited in rapid succession. Transient behavior of soil–bender interaction was characterized using closed-form analytical solutions of single-degree-of-freedom oscillators, numerical solutions using a beam-on-springs method, and measurements from an array of bender elements in a sand model. The time delay caused by soil–bender interaction was calculated to be half of the natural period of the bender element, and this theoretical time delay was supported by experimental data. This system makes it feasible to rapidly collect accurate shear wave velocity information so that transient changes in shear wave velocity can be monitored even if background noise is large. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A8%2811 [...] [article] Fast stacking and phase corrections of shear wave signals in a noisy environment [texte imprimé] / Scott J. Brandenberg, Auteur ; Kutter, Bruce L., Auteur ; Daniel W. Wilson, Auteur . - 2008 . - pp. 1154–1165. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 n°8 (Août 2008) . - pp. 1154–1165 Mots-clés : Wave  velocity  Shear  waves  Soil  modulus  Soil-structure  interaction  Centrifuge  Piezoelectricity Résumé : Hardware, software, and analysis of transient response of sources and receivers are presented for a piezoelectric bender element system designed to measure shear wave velocities in noisy environments. Signal-to-noise ratio is improved by signal stacking, wherein data vectors from many pulses are summed. A new fast-stacking algorithm enables signal quality to be improved much more rapidly than conventional stacking. Conventional stacking is accomplished by repeatedly sending an excitation pulse to a source, waiting for the signal and secondary reflections to pass the receiver and then introducing a subsequent excitation pulse. Using conventional stacking, it is important to wait for the signal and secondary reflections to die out before exciting subsequent pulses. In the new fast-stacking algorithm, a varied interval between consecutive pulses is used so that high quality signals can be obtained even if consecutive pulses are excited in rapid succession. Transient behavior of soil–bender interaction was characterized using closed-form analytical solutions of single-degree-of-freedom oscillators, numerical solutions using a beam-on-springs method, and measurements from an array of bender elements in a sand model. The time delay caused by soil–bender interaction was calculated to be half of the natural period of the bender element, and this theoretical time delay was supported by experimental data. This system makes it feasible to rapidly collect accurate shear wave velocity information so that transient changes in shear wave velocity can be monitored even if background noise is large. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A8%2811 [...]

Weighted residual numerical differentiation algorithm applied to experimental bending moment data / Scott J. Brandenberg in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 6 (Juin 2010) . - pp. 854-863 Titre : Weighted residual numerical differentiation algorithm applied to experimental bending moment data Type de document : texte imprimé Auteurs : Scott J. Brandenberg, Auteur ; Daniel W. Wilson, Auteur ; Mark M. Rashid, Auteur Année de publication : 2010 Article en page(s) : pp. 854-863 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Differential  equations  Bending  moments  Centrifuge  model  Soil  liquefaction  Pile  foundations Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A weighted-residual approach for differentiating one-dimensional discrete data is presented and applied to an experimental program in which distributions of bending moment were measured along a model pile foundation in a centrifuge test. The weighted-residual approach is validated by first differentiating a sinusoidal bending moment distribution, and errors in first and second derivatives associated with various ratios of wavelength to sampling interval are computed. A bending moment distribution from a finite-element simulation of a pile foundation is differentiated using the weighted-residual technique, by fitting cubic splines, and by polynomial regression, and second derivatives are compared with the recorded subgrade reaction distributions. The influence of adding noise to the sampled bending moment distribution prior to differentiation is explored and is found to be most influential when sampling intervals are small. Bending moment data recorded during the centrifuge experiment are double differentiated and uncertainty in strain gauge calibration factors and position are incorporated using a Monte Carlo simulation to assess potential errors in the computed second derivatives. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i6/p854_s1?isAuthorized=no [article] Weighted residual numerical differentiation algorithm applied to experimental bending moment data [texte imprimé] / Scott J. Brandenberg, Auteur ; Daniel W. Wilson, Auteur ; Mark M. Rashid, Auteur . - 2010 . - pp. 854-863. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 6 (Juin 2010) . - pp. 854-863 Mots-clés : Differential  equations  Bending  moments  Centrifuge  model  Soil  liquefaction  Pile  foundations Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A weighted-residual approach for differentiating one-dimensional discrete data is presented and applied to an experimental program in which distributions of bending moment were measured along a model pile foundation in a centrifuge test. The weighted-residual approach is validated by first differentiating a sinusoidal bending moment distribution, and errors in first and second derivatives associated with various ratios of wavelength to sampling interval are computed. A bending moment distribution from a finite-element simulation of a pile foundation is differentiated using the weighted-residual technique, by fitting cubic splines, and by polynomial regression, and second derivatives are compared with the recorded subgrade reaction distributions. The influence of adding noise to the sampled bending moment distribution prior to differentiation is explored and is found to be most influential when sampling intervals are small. Bending moment data recorded during the centrifuge experiment are double differentiated and uncertainty in strain gauge calibration factors and position are incorporated using a Monte Carlo simulation to assess potential errors in the computed second derivatives. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i6/p854_s1?isAuthorized=no