Attenuator systems — an old method to deviate rocks but a new testing method for developing a design concept
Notice bibliographique
Résumé
Rockfall attenuator systems, also known as hybrid rockfall barriers or hanging nets, are a widely applied rockfall mitigation method. Although they are conceptually a straight forward design, to–date, a definitive design guide remains elusive. Among some of the first testing of these systems e.g. Glover et al. 2012, a boarder understanding of the key mechanics, with which they function, has been attained. For example, the process of deflecting rocks to increased ground contact and catching and tangling of the rocks in the attenuator systems has been observed. Nonetheless, these observations remain to be quantified in detail, so they could be developed into a design guide. Addressing this need, a joint testing program is being carried out by Wyllie & Norrish Rock Engineers Ltd. and Geobrugg North America, to measure and validate the performance of rockfall attenuator systems. The preliminary stages of full-scale testing have been conducted at the Nicolum Quarry in Hope, British Columbia, Canada. Tests were conducted using natural rocks of different sizes, <0.5 m³, and steel reinforced concrete cubes, with dimensions of 0.42 and 1.0 m³, dropped into a slope, with a height potential of 60 m, leading to impact with the attenuator netting. The preliminary tests were documented with high speed cameras and load cells measuring the forces in the support ropes. The videos were analysed to determine changes in the rock’s kinetic energy, and the deflection of the attenuator net. The objectives of the tests were to find how to optimise system designs to minimise the impact energy absorbed by the netting and support structure. The maximum impact energy achieved during the preliminary test series was in the order of 600 kJ. Following these initial tests, a second test series was performed in January 2016. Additional to the high speed video and load cell measurements, some experiments involved a novel rock motion logger integrated into the blocks centre of mass. The rock motion logger permitted the rocks accelerations and rotations to be captured during contact with the netting. For the first time, measurements of this kind have been made for attenuators and offer detailed insights into the mechanics of the attenuation process. Further work, in the development of rockfall attenuator systems, is to analyse existing systems, which have been impacted by natural rocks, gaining an estimate of their performance. Alongside these observations, the experimental data is being analysed in detail to refine a new design concept of attenuator barriers. Further results will be given in this paper.
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 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 | 0,004 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,003 |
| Communication savante | 0,002 | 0,003 |
| Science ouverte | 0,002 | 0,002 |
| Intégrité de la recherche | 0,001 | 0,003 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,010 | 0,003 |
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 ».