Documents disponibles écrits par cet auteur

Analysis of climatic influences on slope microseismic activity and rockfalls / Cristina Occhiena 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. 1012–1021 Titre : Analysis of climatic influences on slope microseismic activity and rockfalls : Case study of the matterhorn peak (Northwestern Alps) Type de document : texte imprimé Auteurs : Cristina Occhiena, Auteur ; Marina Pirulli, Auteur Année de publication : 2012 Article en page(s) : pp. 1012–1021 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Slope  stability  Monitoring  Temperature  effects  Microseismic  waves Résumé : Rock instability and rockfalls are commonly preceded by the initiation and propagation of cracks. This process is accompanied by the release of microseismic energy, which can be detected by means of an appropriate monitoring system. Because an increase in rockfall events have been observed in the Matterhorn Peak area since 2003, in 2007 a microseismic monitoring system and a thermometric monitoring system were installed on the Italian side of the Matterhorn peak, close to the J. A. Carrel hut, as part of the Interreg IIIA Alcotra “PERMAdataROC” project. The objective of the installation was to determine whether this instability increase was connected to climatic fluctuations. Detailed analysis of the recorded microseismic data shows a spatial concentration of microseismic activity on the western side of the investigated slope, and a correlation of these data with thermal information shows that the temporal concentration of the microseismic activity could be traced back to the transitions from warm to cold periods. Cold periods, characterized by a continuous and rapid temperature decrease in time, incurred a higher average daily number of microseismic events. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000662 [article] Analysis of climatic influences on slope microseismic activity and rockfalls : Case study of the matterhorn peak (Northwestern Alps) [texte imprimé] / Cristina Occhiena, Auteur ; Marina Pirulli, Auteur . - 2012 . - pp. 1012–1021. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 8 (Août 2012) . - pp. 1012–1021 Mots-clés : Slope  stability  Monitoring  Temperature  effects  Microseismic  waves Résumé : Rock instability and rockfalls are commonly preceded by the initiation and propagation of cracks. This process is accompanied by the release of microseismic energy, which can be detected by means of an appropriate monitoring system. Because an increase in rockfall events have been observed in the Matterhorn Peak area since 2003, in 2007 a microseismic monitoring system and a thermometric monitoring system were installed on the Italian side of the Matterhorn peak, close to the J. A. Carrel hut, as part of the Interreg IIIA Alcotra “PERMAdataROC” project. The objective of the installation was to determine whether this instability increase was connected to climatic fluctuations. Detailed analysis of the recorded microseismic data shows a spatial concentration of microseismic activity on the western side of the investigated slope, and a correlation of these data with thermal information shows that the temporal concentration of the microseismic activity could be traced back to the transitions from warm to cold periods. Cold periods, characterized by a continuous and rapid temperature decrease in time, incurred a higher average daily number of microseismic events. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000662

Morphology and substrate control on the dynamics of flowlike landslides / Marina Pirulli in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 2 (Fevrier 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 2 (Fevrier 2010) . - pp. 376-388 Titre : Morphology and substrate control on the dynamics of flowlike landslides Type de document : texte imprimé Auteurs : Marina Pirulli, Auteur Article en page(s) : pp. 376-388 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Landslides  Numerical  analysis  Dynamic  models  Rheology Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A numerical model set up to simulate rapid flowlike landslide motion across three-dimensional terrain has been used to investigate the capability of various constitutive relationships to model the dynamics of complex events characterized by a changing type of substrate and morphology (e.g., glacier, bends). The numerical procedure is based on a continuum mechanics approach and on depth-averaged St. Venant equations for shallow flows. The developed RASH3D code includes the possibility of using several rheological laws, whose parameter values can vary along the runout path. Two rock avalanche cases, with some morphological peculiarities along the propagation path, have been numerically back-analyzed with both a frictional and a Voellmy rheology. Of the two considered rheologies, the Voellmy model produces the most consistent results in terms of runout area as well as velocity values. The main drawbacks of the frictional model are the tendency to predict excessive spreading of the mass and to overestimate the velocities. The results show that, when a complex problem of runout of rapid flowlike landslides has to be analyzed, it is necessary to have detailed knowledge of the geological and morphological features and to resort to increasingly complex rheologies DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...] [article] Morphology and substrate control on the dynamics of flowlike landslides [texte imprimé] / Marina Pirulli, Auteur . - pp. 376-388. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 2 (Fevrier 2010) . - pp. 376-388 Mots-clés : Landslides  Numerical  analysis  Dynamic  models  Rheology Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A numerical model set up to simulate rapid flowlike landslide motion across three-dimensional terrain has been used to investigate the capability of various constitutive relationships to model the dynamics of complex events characterized by a changing type of substrate and morphology (e.g., glacier, bends). The numerical procedure is based on a continuum mechanics approach and on depth-averaged St. Venant equations for shallow flows. The developed RASH3D code includes the possibility of using several rheological laws, whose parameter values can vary along the runout path. Two rock avalanche cases, with some morphological peculiarities along the propagation path, have been numerically back-analyzed with both a frictional and a Voellmy rheology. Of the two considered rheologies, the Voellmy model produces the most consistent results in terms of runout area as well as velocity values. The main drawbacks of the frictional model are the tendency to predict excessive spreading of the mass and to overestimate the velocities. The results show that, when a complex problem of runout of rapid flowlike landslides has to be analyzed, it is necessary to have detailed knowledge of the geological and morphological features and to resort to increasingly complex rheologies DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...]