Abstract

Thorough knowledge of brittle phenomena around underground excavations is of paramount importance for predicting the extension and shape of the failed zone and assisting in assessing adequate support and reinforcement systems. This behaviour is difficult to capture in conventional continuum modelling approaches, requiring the development of advanced constitutive models. A continuum constitutive approach based on the Hoek-Brown failure criterion and enhanced by introducing a softening rule to replicate the brittle behaviour of rock masses and associated failure due to dilatating sharing has been recently proposed. In this paper, this new Hoek-Brown with Softening model is adopted to predict the progressive brittle failure of the Lac du Bonnet granite at the Underground Research Laboratory Mine-by test tunnel. The results confirm the capability of the constitutive approach to replicate the brittle behaviour associated with strain localization. 

This paper was presented at the 15th ISRM Congress, Salzburg, Austria, October 2023, and is available here:
Modelling brittle rock mass behaviour in deep underground excavations - Cammarata, et al. (2023); https://eposter.at/ISRM2023/data/PDF/1209.pdf