Dr. Jennifer Day gave a virtual research presentation for the American Rock Mechanics Association (ARMA) on Friday, March 22. The presentation is part of a series called, ARMA Future Leader Webinar Series.
The presentation is titled, "Impacts of hydrothermal veins on geomechanics from mineral grain to excavation scales".
The recording can be viewed on YouTube: https://www.youtube.com/watch?v=ZkwwLEQA6uk
Abstract: Hydrothermal veins are a geological complexity often associated with base metal ore deposits, such as porphyries and skarns, and have been found to influence geomechanical rock properties of laboratory specimens as well as rockmass stability around deep excavations. Vein characteristics that control behaviour include mineralogy, mineral grain configuration, vein and vein network geometries, and relationship to host rock lithology. My research team has developed methods to include hydrothermal veins in field rockmass characterization through the Composite Geological Strength Index, drill core logging and laboratory sample selection protocols, and brittle overbreak prediction. At the laboratory testing scale, our work highlights the importance of including veined specimens in test programs to capture representative rock properties (stiffness, brittle damage thresholds, and strength), illustrates differing strength influence of strengthening or weakening veins, and explores the influences of vein orientation and thickness on emergent specimen strength. Vein microstructure is also an important control on emergent specimen strength where, for example, unconfined compressive strength specimens with antitaxial veins induce weaker specimen strength compared to those with syntaxial veins. This work involves development of calibrated numerical simulations to supplement the physical laboratory research activities. This presentation will provide multi-scale insight to hydrothermal vein geomechanics and recommendations for including hydrothermal veins in modern rock engineering design