Suction effects on the compressibility and creep of crushable sands

Rodrigo Osses, Carlos Ovalle, Jubert Pineda, Sandra Linero, Stephen Fityus

In the proceedings of GeoSt. John's 2019: 72nd Canadian Geotechnical Conference

Session: Dams and Embankments

ABSTRACT: An experimental laboratory study of the compressibility and creep of two crushable sands is presented, by means of oedometric compression tests in partially saturated samples. The material humidity is controlled by the vapor transfer technique, in order to cover a wide range of total suction up to 340 MPa. The results show that, as suction decreases (i.e. humidity increases), both compressibility and creep deformations increase. The deformation mechanism is characterized by an instantaneous strain that does not depend on suction, and by creep strains which strongly depends on suction. This phenomenon has applications in engineering designs of geotechnical structures, such as rockfill dams, mining rock waste dumps and railway ballast, where granular materials are subjected to significant changes in environmental conditions that could promote hydro-mechanical degradation at long-term.

RÉSUMÉ: Une étude expérimentale en laboratoire de la compressibilité et du fluage de deux sables est présentée à l'aide d'essais de compression uniaxiale sur des échantillons partiellement saturés. L'humidité du matériau est contrôlée par la technique de transfert de vapeur afin de couvrir une large plage de succion totale allant jusqu'à 340 MPa. Les résultats montrent que, lorsque la succion diminue (i.e. a compressibilité et le fluage augmentent, en raison dúne augmentation de la rupture des grains. Le mécanisme de déformation se caractérise par une déformation instantanée ne dépendant pas de la succion et, deuxièmement, par des déformations de fluage fortement dépendantes de la succion. Ce phénomène a des applications dans la conception des ouvrages géotechniques, tels que les barrages en enrochement, les halles de roches stériles minières et le ballast des chemins de fer, où les matériaux granulaires sont soumis à des modifications importantes des conditions environnementales susceptibles de favoriser la dégradation hydro-mécanique à long terme.

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Cite this article:
Rodrigo Osses; Carlos Ovalle; Jubert Pineda; Sandra Linero; Stephen Fityus (2019) Suction effects on the compressibility and creep of crushable sands in GEO2019. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Geo2019Paper151,author = Rodrigo Osses; Carlos Ovalle; Jubert Pineda; Sandra Linero; Stephen Fityus,title = Suction effects on the compressibility and creep of crushable sands ,year = 2019}