A novel method of estimating earthquake durations for the analysis of floor vibrations of nuclear power plants
Notice bibliographique
Résumé
• A new method is developed to estimate the duration of ground motions. • It is suitable for floor vibration analyses of nuclear facilities on hard rock. • Duration is driven by the linear part of energy accumulation. • For rupture distances <100 km duration seems to be insensitive of moment magnitude. • The method predicts shorter durations than 5%-75% accumulation of Arias intensity. Many low-seismicity countries such as Finland have adopted IAEA requirements and recommendations for seismic design of new and existing nuclear power plants (NPPs). In low seismic regions, the structural seismic design is associated with floor vibration of NPPs. The floor vibration analysis is usually conducted in the time domain for which maximum amplitudes are retrieved from design spectra while the duration of ground motion is estimated as an interval between 5% and 75% of accumulation of the Arias intensity. As this method was developed for active seismic regions, it often overestimates the duration for the regions with low seismicity. The present article introduces a new twofold method for estimating the duration. First, the Arias intensity is calculated for a complete and consecutively reduced accelerograms resulting in a deviation curve. Second, this curve is simplified by a piecewise linear regression fitting. The simplified deviation curve has a linear time frame that includes the most significant part of the Arias intensity. The length of the time frame defines the effective duration of a specific ground motion. This implies that the effective duration depends directly on the ground motion instead of predefined percentiles of the Aries intensity. In this study, the method was applied to a set of ground accelerations adopted from eastern Canada, which is geologically similar to the Fennoscandian Shield where appropriate recordings are absent. The results showed that the durations depend on distance, but they were insensitive of magnitude for short rupture distances. This indicates that smaller events can also be useful for estimating the durations even though they do not meet the requirement of design basis earthquake in terms of the peak ground acceleration. The durations obtained with the proposed method were typically shorter than those based on the 5%–75% criterion. The durations received can be used to generate the acceleration time histories compliant with the design response spectra. We also propose durations with different rupture distances for the seismic design of the structures, systems, and components of nuclear facilities in Finland. In a feasibility study, we calculated floor vibrations of a generic reactor building using 3D finite element analysis. The results show that floor accelerations are very similar, when the base accelerogram is complete or shortened to the length proposed in this study.
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 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
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 ».