Design and development of a new rockbold load measuring device
Bibliographic record
Abstract
Cliquez ici pour la version française de ce rapport_x000D_ Une nouvelle technologie permettant de mesurer la charge axiale des boulons d'ancrage mécaniques et des « rebars » (boulons à la résine) dans les mines souterraines a été conçue et développée en laboratoire. Cette technologie repose sur un système désigné du nom de SAFEBOLT (Stress And Force Evaluator in BOLTs), qui réunit trois composantes : 1) le mesureur de charge SAFEBOLT installé dans la tête des boulons, 2) un module d'affichage et 3) un câble de raccordement. Un banc d'essai adapté a été construit en laboratoire afin d'assurer le calibrage et la vérification des boulons instrumentés avant qu'ils ne soient envoyés dans les mines pour y être utilisés._x000D_ Trois mines souterraines ont pris part au projet, soit les mines Doyon, Bousquet et Niobec. Aussi bien des boulons à ancrage mécanique que des boulons à la résine ont été instrumentés et installés sur le terrain. Nous avons fabriqué et monté avec succès les instruments SAFEBOLT sur des boulons d'ancrage et des « rebars » d'une longueur de 5 pi (1,5 m) à 7 pi (2,1 m). Les leçons tirées des premiers essais sur le terrain ont permis d'améliorer la conception du dispositif monté sur la tête des boulons de telle sorte qu'ils résistent à la manutention brutale dont ils font l'objet en cours d'installation, de même qu'aux effets subséquents des dynamitages survenant dans les parages._x000D_ Les installations effectuées sur le terrain démontrent que la technologie SAFEBOLT promet de devenir un excellent outil de suivi de la charge des boulons, dans la mesure où elle est simple à utiliser, où elle s'est révélée fiable et où elle bénéficie désormais d'une construction robuste. Le présent rapport souligne les caractéristiques et les limites de la technologie SAFEBOLT. Un guide d'utilisation a également été joint en annexe._x000D_ Abstract_x000D_ A new technology for the measurement of axial load on rockbolts and rebars in underground mines has been designed and developed in the laboratory. The technology is known as SAFEBOLT (Stress And Force Evaluator in BOLTS). The SAFEBOLT system consists of three components: 1) the SAFEBOLT device installed in the bolt head, 2) a readout unit, and 3) a connecting cable. A special test rig was constructed in the laboratory to enable the calibration and verification of the instrumented bolt before they are sent to the mines for installation._x000D_ Three underground mines have participated in the project, namely Doyon, Bousquet and Niobec. Both mechanically anchored rockbolts and rebars were instrumented and installed in the field. The SAFEBOLT instruments were successfully fabricated and installed on rockbolts and rebars of 5 to 7 foot-long. The lessons learned from the first field trials helped to improve the design of the instrument connector on the bolt head to sustain the severe handling during the installation, and subsequent effects due to nearby blasting._x000D_ Field installations show that SAFEBOLT technology has the potential to become an excellent tool for monitoring the load on bolts, as it is simple to use, reliable and has now a rugged construction. The report highlights the features and limitations of SAFEBOLT technology. A user’s manual is presented at the end of the report.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.013 | 0.006 |
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".