Documents disponibles écrits par cet auteur

An exercise on slope stability and perfect elastoplasticity / C. Di Prisco in Géotechnique, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 11 (Novembre 2010) . - pp. 923-934 Titre : An exercise on slope stability and perfect elastoplasticity Type de document : texte imprimé Auteurs : C. Di Prisco, Auteur ; F. Pisano, Auteur Année de publication : 2011 Article en page(s) : pp. 923-934 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Strain  localisation  Theoretical  analysis  Slopes  Liquefaction  Plasticity  Failure Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : In this paper the stability of an infinitely long granular slope is addressed in the framework of small-strain perfect elastoplasticity. The problem is approached by discussing the condition of strain localisation and, through a reinterpretation of the concept of ‘angle of natural repose', a modified strategy for evaluating the slope safety factor is introduced. The angle of natural repose is demonstrated to differ substantially from the material internal friction angle (as this can be determined from standard triaxial tests). The role of non-associativeness is critically discussed and simple shear stress paths are numerically simulated: pseudo-hardening and pseudo-softening regimes are described. The influence of the loading history on the overall ductility/brittleness of the system mechanical response is analysed. To stress the dependency of the angle of natural repose on the material ductility/brittleness, additional simple shear numerical results are illustrated for the case of a strain-softening constitutive relationship. Finally, the stability of the stratum under undrained conditions is critically tackled with reference to the phenomenon of static liquefaction of loose sands. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.p.040 [article] An exercise on slope stability and perfect elastoplasticity [texte imprimé] / C. Di Prisco, Auteur ; F. Pisano, Auteur . - 2011 . - pp. 923-934. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 11 (Novembre 2010) . - pp. 923-934 Mots-clés : Strain  localisation  Theoretical  analysis  Slopes  Liquefaction  Plasticity  Failure Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : In this paper the stability of an infinitely long granular slope is addressed in the framework of small-strain perfect elastoplasticity. The problem is approached by discussing the condition of strain localisation and, through a reinterpretation of the concept of ‘angle of natural repose', a modified strategy for evaluating the slope safety factor is introduced. The angle of natural repose is demonstrated to differ substantially from the material internal friction angle (as this can be determined from standard triaxial tests). The role of non-associativeness is critically discussed and simple shear stress paths are numerically simulated: pseudo-hardening and pseudo-softening regimes are described. The influence of the loading history on the overall ductility/brittleness of the system mechanical response is analysed. To stress the dependency of the angle of natural repose on the material ductility/brittleness, additional simple shear numerical results are illustrated for the case of a strain-softening constitutive relationship. Finally, the stability of the stratum under undrained conditions is critically tackled with reference to the phenomenon of static liquefaction of loose sands. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.p.040

Rockfall impacts on sheltering tunnels / F. Calvetti in Géotechnique, Vol. 62 N° 10 (Octobre 2012) 

Public ISBD [article]  in Géotechnique > Vol. 62 N° 10 (Octobre 2012) . - pp. 865 –876 Titre : Rockfall impacts on sheltering tunnels : Real-scale experiments Type de document : texte imprimé Auteurs : F. Calvetti, Auteur ; C. Di Prisco, Auteur Année de publication : 2012 Article en page(s) : pp. 865 –876 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Full-scale  tests  Soil/structure  interaction  Landslides  Design  Tunnels Résumé : In this paper the results of a series of rockfall impact tests on a sheltering tunnel are discussed. A reinforced-concrete (RC) sphere (mass 850 kg, diameter 0·9 m) was dropped (falling height ranging between 5 m and 45 m) on a tunnel along a road in the Dolomites. This experimental programme represents the extension of a previous one, performed at Politecnico di Milano (Campus Bovisa), when the same RC sphere was dropped on a circular pool filled with a loose sand stratum. The new programme is characterised by larger falling heights and the monitoring of the mechanical response of the shelter. A series of instruments have been employed to measure impact forces, stress propagation within the absorbing soil stratum on top of the shelter, and its deflection. The results, which are in good agreement with available literature data, are presented with the aim of highlighting the features of the complex impact event and discussing the engineering factors to be considered for conceiving a realistic and reliable design approach. The main conclusion is that the impact force is unaffected by the presence of the plate, and that the stress increment on the structure is slightly reduced by the structure deflection, which can be neglected for design purposes without unreasonable levels of conservatism being introduced. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.P.036 [article] Rockfall impacts on sheltering tunnels : Real-scale experiments [texte imprimé] / F. Calvetti, Auteur ; C. Di Prisco, Auteur . - 2012 . - pp. 865 –876. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 62 N° 10 (Octobre 2012) . - pp. 865 –876 Mots-clés : Full-scale  tests  Soil/structure  interaction  Landslides  Design  Tunnels Résumé : In this paper the results of a series of rockfall impact tests on a sheltering tunnel are discussed. A reinforced-concrete (RC) sphere (mass 850 kg, diameter 0·9 m) was dropped (falling height ranging between 5 m and 45 m) on a tunnel along a road in the Dolomites. This experimental programme represents the extension of a previous one, performed at Politecnico di Milano (Campus Bovisa), when the same RC sphere was dropped on a circular pool filled with a loose sand stratum. The new programme is characterised by larger falling heights and the monitoring of the mechanical response of the shelter. A series of instruments have been employed to measure impact forces, stress propagation within the absorbing soil stratum on top of the shelter, and its deflection. The results, which are in good agreement with available literature data, are presented with the aim of highlighting the features of the complex impact event and discussing the engineering factors to be considered for conceiving a realistic and reliable design approach. The main conclusion is that the impact force is unaffected by the presence of the plate, and that the stress increment on the structure is slightly reduced by the structure deflection, which can be neglected for design purposes without unreasonable levels of conservatism being introduced. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.P.036