Empirical stope design at the Ruttan Mine, Sherritt Gordon Mines Ltd.
Notice bibliographique
Résumé
This thesis evaluates the factors that influence the stability of large, open stopes for an existing mining operation. The Ruttan mine, a 6000 tpd base metal operation has mined by open stoping methods since 1979. This has resulted in a large data base of information which includes forty-three (43) stopes at various stages of extraction, thereby yielding 133 observations of: Rock Mass Rating (footwall, hanging wall, ore) Stope Dimensions (height, width, length) Observed Dilution Excavation Rates Stope Configuration (isolated, rib, echelon) Mining Sequence/Method In addition, the observations were supplemented with in-situ measurements, structural mapping, stress and deformation monitoring and historical observation. It was concluded through numerical modelling, observation and measurement that the hanging wall and footwall of the individual stopes are in a state of relaxation, thereby enabling structural blocks to be released. This would generally be the case for most stope geometries whose major in-situ stress direction lies perpendicular to the long dimension of the opening. Consequently the critical parameters were quantified in terms of their effect on dilution by employing multivariate analysis. The relationships derived were entirely confined to the Ruttan operation as they were empirically delineated and quantified. The Ruttan operation is a multi-lensed ocebody with individual stopes dipping at 70°. The following empirically derived relationships were found to correlate strongly with the observed dilution: [See Thesis for Diagrams] where: DIL(%) - refers to predicted stope dilution (tons waste/tons reserves) RMR(%) - Rock Mass Rating of the critical wall contact, generally the hanging wall Exp. Rate('1000m²/mth) - refers to the rate at which the hanging wall is exposed (excavation rate/stope width) Area(m²) - refers to the exposed surface area of the hanging wall r , s – Refers to the correlation coefficient and the unbiased standard error of estimate respectively. The empirical relationships were related to stopes mined subsequent to the study and yielded errors of estimate (ŝ) of predicted dilution to within 2 - 4% of the observed dilution. The blast induced dilution was subsequently added to the predicted dilution. This value is difficult to estimate and is presently recorded as the dilution that is observed as the slot (initial cut) is being excavated. The design equations were based on a relatively large data base, considering, that the works of Bieniawski (1973) and Barton (1974) were based on 49 and 200 case histories respectively. It is suggested that the empirical methods of design outlined in this thesis be attempted at other operations where structural failure is the main factor contributing to stope dilution. This would augment the data base and extend its applicability. Parameters unique to Ruttan that were employed in establishing the data base are as follows: hanging wall and footwall of all stopes are In relaxation groundwater is not a factor mean stope inclination = 68° ± 9° mean stope dilution = 10% ± 6% mean RMR = 56% ± 20% mean exposure rate = 0 . 18m² ± .09m² (x 1000)/mth mean excavation rate = 2700m³ ± 1300m³/mth mean span = 31m ± 13m mean stope width = 15m ± 8m mean stope height = 68m ± 20m mean exposed surface area = 2250m² ± 1120m² mean stope depth = 360m ± 48m below surface mean blast correction factor = 3% ± 6%
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,003 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».