Mitigation of an open shaft at a legacy mine site in British Columbia, Canada using polyurethane foam
Notice bibliographique
Résumé
Legacy underground mining sites may include the presence of unsecured openings to surface, such as shafts, vent raises, and portals that pose a risk to public and animal safety. This paper presents a case study of the design methodology and use of a polyurethane foam (PUF) plug for the mitigation of an open shaft at a legacy mine site in British Columbia, Canada. Common methods of securing openings to surface include the design and construction of concrete caps or plugs, installation of steel grates, and/or placement of backfill. The method chosen depends on the remediation objectives, desired lifespan, and project setting. Openings in remote locations may require special considerations to optimise cost and reduce impacts on the environment due to the increased difficulty in transporting equipment and materials to the project site. The shaft that is the subject of this paper had previously been backfilled several times with rockfill by the site Owner, but the backfill had either migrated and/or settled over time, eventually resulting in an expression of surface subsidence. The shaft location is within steep terrain and only accessible from an unsanctioned foot and bike trail which limits access with mobile equipment. The use of PUF was advantageous in this situation due to its portability and ability to be hand-mixed and hand-poured into the opening, reducing the need to transport equipment to the project site which would have impacted the surrounding forest terrain. The PUF plug was constructed to prevent further subsidence and seal off access to the shaft to provide a long-term mitigative solution. The plug was required to have sufficient density, strength, and thickness to resist anticipated natural loads, and was designed to incorporate cementitious grout and backfill layers to provide ultraviolet (UV) and fire protection, respectively. An inspection port was also included in the design to facilitate long-term performance monitoring. Technical specifications and a work methodology for mitigating the open shaft with PUF were developed to meet the design basis. A quality assurance program consisting of on-site observations and monitoring of site conditions, as well as sampling of the PUF material for third-party density and strength testing was also carried out. A post-construction monitoring program will be implemented beginning in summer 2023, following snow melt, and will consist of visual monitoring at surface and at depth through the installed inspection port.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
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 tête enseignante, 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 ».