The importance of classification for carbonates and mudrocks in engineering

Matthew A. Perras, Mark S. Diederichs

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: Mining and Rock Mechanics

ABSTRACT: Geological classification systems for carbonates and mudrocks were developed to more accurately describe these sedimentary rock types. There appears to be a correlation between the mechanical properties examined in this paper and the geological classification system of Dunham. It was found that the Modulus Ratio of mudrocks is lower than packstones, which is lower than Dolomite. Grains weaker in tension, than the matrix, begin to control the failure process at around 35-40% total volume of the sample, in 2-dimensions. This volume will be lower for real samples. Many characteristics affect fracture initiation and propagation in carbonates and mudrocks. Fractures initiate around grains or pore spaces and propagate through matrix and grains. They can also propagate easily along bedding planes, although the argillaceous content, in carbonates, may arrest propagation. The micro-mechanical behaviour of these materials is a key research focus for storage of nuclear waste in sedimentary rocks.

RÉSUMÉ: Systèmes de classification géologique de carbonates et de pélites ont été élaborés pour décrire plus précisément ces types de roches sédimentaires. Il semble y avoir une corrélation entre les propriétés mécaniques examinées dans le présent document et le système de classification géologique de Dunham. Il a été constaté que le rapport des modules d'argilites est inférieur packstones, ce qui est inférieur Dolomites. Grains plus faible de la tension, que la matrice, de commencer à contrôler le processus de rupture à environ 35-40% du volume total de l'échantillon, en 2-dimensions. Ce volume sera plus faible pour les échantillons réels. Caractéristiques ont une influence sur l'initiation et la propagation de fracture dans les carbonates et pélites. Fractures ouvrir autour des grains ou des pores et se propagent à travers la matrice et des céréales. Ils peuvent également propager facilement le long des plans de stratification, bien que la teneur argileuse, dans les carbonates, peut arrêter la propagation. Le comportement de micro-mécanique de ces matériaux est un domaine de recherche clé pour l'entreposage des déchets nucléaires dans les roches sédimentaires.

Access this article:
Canadian Geotechnical Society members can access to this article, along with all other Canadian Geotechnical Conference proceedings, in the Member Area. Conference proceedings are also available in many libraries.

Cite this article:
Matthew A. Perras; Mark S. Diederichs (2011) The importance of classification for carbonates and mudrocks in engineering in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper492,author = Matthew A. Perras; Mark S. Diederichs ,title = The importance of classification for carbonates and mudrocks in engineering,year = 2011}