COMPARISON OF MINING-INDUCED SEISMICITY WITHIN A FOOTWALL FAULT BETWEEN OVERHAND AND UNDERHAND STOPING METHODS

Atsushi Sainoki, Hani Mitri

In the proceedings of: GeoQuébec 2015: 68th Canadian Geotechnical Conference & 7th Canadian Permafrost Conference

Session: Rock Mechanics and Engineering Geology II / Mécanique des roches et ingénierie géologique II

ABSTRACT: The behaviour of faults in underground mines has been attracting much attention from rock mechanics specialists. In this study, a comparison between overhand and underhand sublevel stoping methods is made whilst focusing on the static and dynamic behaviour of a footwall fault intersecting with a steeply dipping orebody. A mine-wide numerical model representing the geological features is constructed. Using the model, static analyses are performed to extract stopes in the orebody. It is found from the result that the stope extraction with the underhand mining method produces more seismically active conditions on the fault, compared to the overhand method. Then, fault-slip is simulated with an instantaneous change of the friction law from static to dynamic. The analysis indicates that there is no significant difference in the intensity of near-field ground motion between fault-slips induced by the stope extraction with the two mining methods.

RÉSUMÉ: Le comportement des failles dans les mines sous-terraines attire actuellement l™attention des spécialistes en mécanique des roches. Dans cette étude, l™extraction descendante d™un gisement à fort pendage par l™abattage de chantiers remblayés est comparée à l™extraction ascendante du même gisement. Le comportement statique et dynamique d™une faille dans l™éponte inférieure est étudié. Un modèle numérique de la mine représentant les structures géologiques a été construit. Des analyses statiques ont été conduites avec le modèle pour abattre les chantiers. Il est observé que l™extraction descendante du gisement génère des conditions plus sismiquement actives dans la faille que l™extraction ascendante. Ensuite, le glissement de la faille est simulé en changeant instantanément son coefficient de friction de statique à dynamique. L™analyse indique qu™il n™y a pas de différence significative entre l™intensité des mouvements de sol en champ proche entre les glissements de faille induits par les 2 méthodes d™extraction.

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Cite this article:
Atsushi Sainoki; Hani Mitri (2015) COMPARISON OF MINING-INDUCED SEISMICITY WITHIN A FOOTWALL FAULT BETWEEN OVERHAND AND UNDERHAND STOPING METHODS in GEO2015. Ottawa, Ontario: Canadian Geotechnical Society.

@article{060,author = Atsushi Sainoki; Hani Mitri,title = COMPARISON OF MINING-INDUCED SEISMICITY WITHIN A FOOTWALL FAULT BETWEEN OVERHAND AND UNDERHAND STOPING METHODS,year = 2015}