Accounting for intrablock structures at rockmass and laboratory specimen scales

Jennifer J. Day, Matthew D. Clark

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

Session: Rock Mechanics

ABSTRACT: For deep excavations in heterogeneous complex rockmasses that contain hydrothermal veins and other types of intrablock structures, conventional field characterization and laboratory measurement protocols that were developed for numerical geotechnical design of homogeneous rockmasses are no longer adequate. In this paper, rockmass characterization methodologies in the field and laboratory for complex rockmasses are discussed, with particular emphasis on the importance of mineralogical investigation for both the matrix and vein materials. The opportunities for continuum and discontinuum numerical modelling are also discussed based on the availability of different field or laboratory data. Finally, a case study of unconfined compressive strength laboratory tests on three lithological units from the Legacy skarn deposit is presented to demonstrate both weakening and strengthening influences that intrablock structures can have on stiffness and peak strength properties.

RÉSUMÉ: Les protocoles classiques de caractérisation de terrain et de mesure en laboratoire développés pour la conception géotechnique numérique des massifs rocheux homogènes ne sont plus adéquats pour les excavations profondes dans e structures intrablocs. Dans cet article, les méthodologies de caractérisation de terrain et en laboratoire pour les massifs rocheux complexes sont discutées, avec que tant pour les matériaux de la matrice et de la veine. Les possibilités de modélisation numérique en continu et discontinu sont également discutées en fonction de la disponibilité de différentes données de terrain ou de laboratoire. Enfin, une étude e laboratoire de résistance à la compression non confinée sur trois unités lithologiques du gisement de intrablocs peuvent avoir sur les propriétés de rigidité et de résistance maximale.

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Cite this article:
Jennifer J. Day; Matthew D. Clark (2019) Accounting for intrablock structures at rockmass and laboratory specimen scales in GEO2019. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Geo2019Paper548,author = Jennifer J. Day; Matthew D. Clark,title = Accounting for intrablock structures at rockmass and laboratory specimen scales ,year = 2019}