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Gosselin Jeremy M. Dosso Stan E. Askan Aysegul Wathelet Marc Savvaidis Alexandros Cassidy John F. 《Journal of Seismology》2022,26(4):781-821
Journal of Seismology - Seismic site characterization attempts to quantify seismic wave behavior at a specific location based on near-surface geophysical properties, for the purpose of mitigating... 相似文献
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Morphology,structure and kinematics of a rainfall controlled slow‐moving Andean landslide,Peru 下载免费PDF全文
Swann Zerathe Pascal Lacroix Denis Jongmans Jersy Marino Edu Taipe Marc Wathelet Walter Pari Lionel Fidel Smoll Edmundo Norabuena Bertrand Guillier Lucile Tatard 《地球表面变化过程与地形》2016,41(11):1477-1493
The large slow‐moving landslide of Maca is located in the upper Colca valley (southern Peru), a region characterized by a well pronounced rainy period, and intense and recurrent sustained seismicity. The landslide, developed in deep lacustrine deposits, has recently accelerated, threatening the Maca village. This work aims at understanding the rupture mechanism and the causes of the recent landslide reactivation/acceleration. We present a multidisciplinary characterization of the Maca landslide that includes: (i) geological and morphological mapping in the field; (ii) remote sensing analysis using an historical aerial photograph of 1955 and the Pléiades satellite images (2013); (iii) global positioning system (GPS) including time‐series of surveys over 13 years, and continuous measurements over 14 months; (iv) a geophysical campaign with deep electrical resistivity tomography profiles acquired across the landslide mass. Our study shows that this 60 Mm3 landslide, which can be classified as a clay/silt compound landslide, moved by 15 m between 2001 and 2014 with a large inter‐annual velocity variation (up to a factor of 500) depending on the rainfall intensity. We suggest that these dramatic changes in velocity are the result of the combination of a threshold mechanism and the short intense rainy season in Peru. This study reveals three main driving factors acting at different timescales: (i) over several decades, the river course has significantly changed, causing the Maca landslide reactivation in the 1980s due to the erosion of its toe; (ii) at the year scale, a minimum amount of rainfall is required to trigger the motion and this amount controls the landslide velocity; (iii) transient changes in slide velocity may occur anytime due to earthquakes. This study particularly highlights the non‐linear behaviour of the motion with rainfall. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Fiolleau Sylvain Jongmans Denis Bièvre Gregory Chambon Guillaume Lacroix Pascal Helmstetter Agnès Wathelet Marc Demierre Michel 《Landslides》2021,18(6):1981-2000
Landslides - The mass transfer mechanisms in landslides are complex to monitor because of their suddenness and spatial coverage. The active clayey Harmalière landslide, located 30 km south of... 相似文献
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Asten Michael W. Yong Alan Foti Sebastiano Hayashi Koichi Martin Antony J. Stephenson William J. Cassidy John F. Coleman Jacie Nigbor Robert Castellaro Silvia Chimoto Kosuke Cornou Cécile Cho Ikuo Hayashida Takumi Hobiger Manuel Kuo Chun-Hsiang Macau Albert Mercerat E. Diego Molnar Sheri Pananont Passakorn Pilz Marco Poovarodom Nakhorn Sáez Esteban Wathelet Marc Yamanaka Hiroaki Yokoi Toshiaki Zhao Don 《Journal of Seismology》2022,26(4):757-780
Journal of Seismology - Site response is a critical consideration when assessing earthquake hazards. Site characterization is key to understanding site effects as influenced by seismic site... 相似文献
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Fabrice Hollender Cécile Cornou Aline Dechamp Kaveh Oghalaei Florence Renalier Emeline Maufroy Clément Burnouf Sylvette Thomassin Marc Wathelet Pierre-Yves Bard Vincent Boutin Clément Desbordes Isabelle Douste-Bacqué Laetitia Foundotos Cédric Guyonnet-Benaize Vincent Perron Julie Régnier Agathe Roullé Mickael Langlais Deborah Sicilia 《Bulletin of Earthquake Engineering》2018,16(6):2337-2365
Data provided by accelerometric networks are important for seismic hazard assessment. The correct use of accelerometric signals is conditioned by the station site metadata quality (i.e., soil class, VS30, velocity profiles, and other relevant information that can help to quantify site effects). In France, the permanent accelerometric network consists of about 150 stations. Thirty-three of these stations in the southern half of France have been characterized, using surface-wave-based methods that allow derivation of velocity profiles from dispersion curves of surface waves. The computation of dispersion curves and their subsequent inversion in terms of shear-wave velocity profiles has allowed estimation of VS30 values and designation of soil classes, which include the corresponding uncertainties. From a methodological point of view, this survey leads to the following recommendations: (1) perform both active (multi-analysis surface waves) and passive (ambient vibration arrays) measurements to derive dispersion curves in a broadband frequency range; (2) perform active acquisitions for both vertical (Rayleigh wave) and horizontal (Love wave) polarities. Even when the logistic contexts are sometimes difficult, the use of surface-wave-based methods is suitable for station-site characterization, even on rock sites. In comparison with previous studies that have mainly estimated VS30 indirectly, the new values here are globally lower, but the EC8-A class sites remain numerous. However, even on rock sites, high frequency amplifications may affect accelerometric records, due to the shallow relatively softer layers. 相似文献
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Marc Wathelet Denis Jongmans Matthias Ohrnberger Sylvette Bonnefoy-Claudet 《Journal of Seismology》2008,12(1):1-19
Valuable information about one-dimensional soil structures can be obtained by recording ambient vibrations at the surface,
in which the energy contribution of surface waves predominates over the one of other types of waves. The dispersion characteristics
of surface waves allow the retrieval of the shear-wave velocity as a function of depth. Microtremor studies are usually divided
in two stages: deriving the dispersion (or auto-correlation) curve from the recorded signals and inverting it to obtain the
site velocity profile. The possibility to determine the dispersion curve over the adequate frequency range at one site depends
on the array aperture and on the wavefield spectra amplitude that can be altered by filtering effects due to the ground structure.
Microtremors are usually recorded with several arrays of various apertures to get the spectral curves over a wide frequency
band, and different methods also exist for processing the raw signals. With the objective of defining a strategy to achieve
reliable results for microtremor on a shallow structure, we analyse synthetic ambient vibrations (vertical component) simulated
with 333 broadband sources for a 25-m deep soil layer overlying a bedrock. The first part of our study is focused on the determination
of the reliable frequency range of the spectral curves (dispersion or auto-correlation) for a given array geometry. We find
that the wavenumber limits deduced from the theoretical array re sponse are good estimates of the valid spectral curve range.
In the second part, the spectral curves are calculated with the three most popular noise-processing techniques (frequency–wavenumber,
high-resolution frequency–wavenumber and spa tial auto-correlation methods) and inverted indi vidually in each case. The inversions are
performed with a tool based on the neighbour hood algorithm that offers a better estimation of the global uncertainties than
classical linearised methods, especially if the solution is not unique. Several array apertures are necessary to construct
the dispersion (auto-correlation) curves in the appropriate frequency range. Considering the final velocity profiles, the
three tested methods are almost equivalent, and no significant advantage was found for one particular method. With the chosen
model, all methods exhibit a penetration limited to the bedrock depth, as a consequence of the filtering effect of the ground
structure on the vertical component, which was observed in numerous shallow sites. 相似文献
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