Systematic review of georisk in underground hard rock mines

Abstract

Deep mining, driven by the increasing need of the sustainable use of mineral resources yields a possibility to fully extract the untapped deposits. Nevertheless, large depths remain challenging and complex environment. Rockbursts and induced seismicity, considered as georisks, are one of the most relevant risks identified in the field, which threat both safety and economics. Risk management tools and guidelines are essential to maintain safe and economically feasible extraction, but they still need improvements. One such opportunity identified here is the development of on-line georisk management systems, and going even further, a creation of a risk management concept covering the entire mine. This master’s thesis is a part of the On-line Risk Management in Deep Mines (ORMID) project, funded by the Academy of Finland, running under the Mineral Resources and Material Substitution programme.

Systematic review of the literature was conducted to enable addressing the thesis goals: identification of the gaps in research concerning on-line georisk management in underground hard rock mines, establishment of the state-of-the-art of the developments in that topic, and providing recommendations for future research. Three databases were used for the search: Scopus, ScienceDirect, and IEEEXplore. To search the databases 12 keywords and phrases were formulated. The search was conducted in three phases: out of 13 767 studies identified, 98 were taken into manual investigation, and 50 of them were finally included in this master’s thesis.

The gap identified in this study is the lack of research that examines the methods of rockmass stress calculation and forecasting based on the strain measurements. Only two examples of them were obtained in the study. Another issue that comes out is a need of deeper understanding of rockburst phenomenon. Moreover, a very low number of systems capable of on-line georisk management was identified. Dynamic Intelligent Ground Monitoring (Digmine), Mine Seismicity Risk Analysis Program (MS-RAP) and one standard architecture (AziSA) of the on-line georisk management were recognized as the state-of-the-art. To manage the georisks the state-of-the-art method represents an immediate rockburst warning method based on microseismicity analysis, already utilised in Digmine. BurstSupport software aiming to assist the geotechnical engineers in evaluating different rockburst support options in a burst-prone ground was considered as the state-of-the-art georisk mitigation method identified in the study. Identification of these developments resulted from rigorous inclusion and exclusion criteria, selected keywords and databases. Different choice of these would yield dissimilar results, what indicates that not all of the research about the topic of interest was identified. Recommendations and a roadmap addressing upcoming assignments in the ORMID project are presented in this thesis.