A case history of modeling and monitoring of ground movements adjacent to an oil sands mine pit slope

Andrew Bidwell, Rod Kostaschuk, Tim Eaton

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: Mining and Rock Mechanics

ABSTRACT: Project was performed in order to predict the extent and magnitude of mining-induced ground movements. The location of new plant facilities close to the pit crest and sensitive to foundation movements created the need for detailed attention to predicting and monitoring pit slope performance. The hypothesized ground movement mechanism was the development of a progressive failure along a weak layer or layers in the McMurray Formation deposits exposed in the pit slope upon stress relief during mining. The deformation modeling was performed using the finite difference software FLAC, with the model geometry based on the planned pit slope excavation sequence and profile. The soil/rock properties for the model were based on the available geological and geotechnical information, case histories of other large excavations into the McMurray Formation and estimated in-situ horizontal stresses. The actual ground movements adjacent to the pit slope were monitored during the initial years of mining and the pre-mining numerical analysis was revised and calibrated prior the construction of new plant facilities even closer to the pit slope. The revised analyses showed that additional movements would occur during the remainder of mining, the timing of which would overlap with the construction of the new plant facilities. Therefore, an expanded monitoring program was undertaken to help manage the risk of ground movement to the plant facilities. The further monitoring showed that additional ground movement did occur, but with magnitudes and extents that were less than predicted by the revised model.

RÉSUMÉ: Une modélisation des déformations ar les aux mouvements de terrain ont exigés de porter une attention particulière à la prédiction et au suivi du comportement de la psoumis à un déchargement de sols et du rocher utilisées pour la modélisacontraintes in-situ horizontales estimées. Les mouvements réels du terrain au sommet du talus ont été suivis dans les premières années suivant le début de pré-exploitation et ce, avant la constminières futures, incluant pendant la construction des nouvelles installations. En conséquence, un programme de suivi étendu a été mis en place afin de mieux gérer les risques associés aux mouvements de terrain. Les résultats de ce suivi ont démontré que des mouvements de terrain se sont en effets produits, ma

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Cite this article:
Andrew Bidwell; Rod Kostaschuk; Tim Eaton (2011) A case history of modeling and monitoring of ground movements adjacent to an oil sands mine pit slope in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper800,author = Andrew Bidwell; Rod Kostaschuk; Tim Eaton ,title = A case history of modeling and monitoring of ground movements adjacent to an oil sands mine pit slope,year = 2011}