Grant: Discovery Grants Program - Individual

Despite the current financial turmoil, the mining sector is growing, likely with a long cycle period, creating a unique economic opportunity for Canada to expand its mineral production. Finding a new ore body, however, takes years and getting a new mine permitted and operational typically takes 8 to 15 yrs. Hence, it is most attractive to expand the mine life by going deeper. Unfortunately, mining at depth is more costly and investors are only willing to commit capital if a project can be executed at low risk to workers, investors, society and the environment. This research focuses on the first two aspects. The stakeholders, as recipients of research, have identified 3 geomechanics aspects needing fundamental and applied research: (1) Rock and rock mass strength for engineering at depth; (2) Assessment and mitigation of risk when mining in structurally complex ore bodies; and (3) Engineering design for optimal constructability to achieve high rates of advance. The proposed research deals with challenges identified through recent experiences from deep underground construction and mines. Based on field observations, 3 key deficiencies in current rock engineering are identified: (1) Rock and Rock mass failure criteria - standard approaches for strength determination and respective constitutive models are flawed for brittle rock; (2) Strength at depth - based on field experience, the hypothesis is advanced that the rock mass strength at depth is underestimated; potentially leading to uneconomic designs; (3) Design for constructability - at depth, failure processes are more pervasive and raveling / stand-up time issues dominate design; leading to delays and cost overruns. The research, involving fundamental studies, field monitoring and observations, and back-analyses, will develop means to properly characterize the rock at depth, to obtaining appropriate numerical modeling and design parameters, and to develop ground control means and risk mitigation measures for mining and construction in highly stressed rock.