Large Scale Experimental Storm Impact on Nourished Beach Using Cobble-Gravel-Sand Mix
Notice bibliographique
Résumé
We have investigated beach stability against storm waves. The studies are done in relation to eroded beaches. We are testing a cobble-sand-gravel mixture as a means of using a soft method for coastal protection on nourished beaches. A physical model of an existing beach was built at scale 1:3. The cobble/sand grain size is in 1:3 scale while the gravel is 1:1.5 scale. The large scale experimental flume tests have been set-up in the new outdoor 120 m long flume in Québec city, Canada. The tests were conducted over two test seasons (2013–14). While we in the first test season studied impact on the beach due to incoming regular plunging breakers, the last season contained tests with incoming irregular plunging breakers on the beach with/without tidal variation. Herein, we primarily report on the wave impact due to irregular plunging breakers on constant and tidal varying water depths. The wave-tide interactions were conducted with a tidal range of 1 m in relation to beaches with steep beach slopes (1:10, 1:5, 1:1). The model inlet significant wave height was 1.1–1.5 m corresponding to equivalent prototype waves in the range of max. wave heights of 6–8.5 m with dominant periods of 12 s in water depth of about 15 m and tidal range of 3 m. In general, the Equilibrium Beach Profile (EBP) was reached after exposure to about 10,000 plunging breakers or the equivalent of five storms assuming each lasting 3 hours. A cobble berm was formed rapidly on the top of the beach, protecting the backshore against wave action and flooding while finer sediment was transported “offshore”. Beach width reduction was observed when the initial slope of the beach fill material exceeded the equilibrium beach slope. Sediment grain size sorting along the beach profile is discussed and compared to existing beach models, and EBP was compared to several EBP equations. From a coastal management perspective, in terms of durability, the mixed cobble-sand-gravel material is showing promise as a material to use for coastal protection. It is highly absorbent and the beach tends to maintain its shape over long time when exposed to several storms. However, storm surges in the combination with high tides can results in excessive run-up and potential flood risks. The stabilized beach typically had slopes of 1:7–1:9 independent of the initial slope. We found that irregular seas result in a less pronounced trough in the beach profile in the swash zone than incoming regular plunging breakers. The tidal interaction was further advantageous, naturally shifting the material back and forth. However, other materials and other sensitivity studies are necessary in order to provide firm conclusions about the usage of the cobble-gravel-sand mixture for coastal protection.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| 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) | 0,002 | 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 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 ».