Experience in Australia with the application of the Mathews method for open stope design
Bibliographic record
Abstract
A significant open stope stability data base was developed for an Australian mine which is similar in size to the North American data base used to develop the Mathews' stability graph method. Sufficient case histories were developed to test the validity of using the two extant versions of the Mathews' method for predicting the stability of stope walls at the case study mine. Both gave similar predictions, despite different stability zonings and some differences in the way that the stability numbers are calculated. In general, the stope surfaces that were observed as unstable plotted well on both stability graphs. However, a significant percentage of stable stopes were predicted to be unstable and this percentage was much greater than that for the North American data base, indicating that the method gave more conservative predictions for this particular case study. The study indicated that the two versions of the Mathews' method may give reasonable first approximations to stope dimensions where local experience is lacking or has not been documented. Nevertheless, the development of site specific zones of stability improved the predictive capability of the technique. Case histories documented by the authors, which included stope surfaces with a hydraulic radius up to 55 m, were combined with the Canadian data base and a modified general Mathews' stability graph presented.A significant open stope stability data base was developed for an Australian mine which is similar in size to the North American data base used to develop the Mathews' stability graph method. Sufficient case histories were developed to test the validity of using the two extant versions of the Mathews' method for predicting the stability of stope walls at the case study mine. Both gave similar predictions, despite different stability zonings and some differences in the way that the stability numbers are calculated. In general, the stope surfaces that were observed as unstable plotted well on both stability graphs. However, a significant percentage of stable stopes were predicted to be unstable and this percentage was much greater than that for the North American data base, indicating that the method gave more conservative predictions for this particular case study. The study indicated that the two versions of the Mathews' method may give reasonable first approximations to stope dimensions where local experience is lacking or has not been documented. Nevertheless, the development of site specific zones of stability improved the predictive capability of the technique. Case histories documented by the authors, which included stope surfaces with a hydraulic radius up to 55 m, were combined with the Canadian data base and a modified general Mathews' stability graph presented.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.011 | 0.019 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".