Seismic risk assessment is critical for ensuring the resilience and safety of structures in earthquake-prone regions. Traditional methods of seismic input often rely on recorded accelerograms, which may not fully capture the variability and complexity of earthquake ground motions. Physics-Based Simulations (PBS) offer a promising alternative, generating ground motion time series based on detailed physical models of earthquake processes. These simulations can provide more accurate and site-specific representations of seismic events, potentially leading to improved structural analysis and design. This thesis aims to validate the use of PBS for seismic ground motions by comparing their effectiveness with recorded signals through non-linear dynamic analysis, specifically focusing on the relationship between Interstory Drift Ratio (IDR) and various Intensity Measures (IMs). To achieve this goal, three types of reinforced concrete buildings—a 1-storey, 4-storey, and 8-storey structure—were analyzed using both recorded and simulated ground motions. The IMs considered included Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), Spectral Acceleration at the first-mode period (Sa(T1)), average spectral acceleration (Sa,avg), Housner Intensity (HI), and Arias Intensity (IA). The non-linear dynamic analyses (NLDAs) were performed to evaluate the IDR responses of the buildings under different seismic scenarios. The results indicate that PBS provide consistent and reliable predictions of IDR when compared to recorded ground motions, particularly for PGV, Sa(T1), Sa,avg, and HI. These IMs demonstrated similar slopes, intercepts, and standard deviations, suggesting that PBS can effectively replicate the structural response observed in recorded signals. In contrast, PGA and IA showed greater discrepancies, indicating that they may be less effective for use in seismic assessments when derived from simulated data. Overall, this research validates the application of PBS in seismic analysis, highlighting their potential to enhance the understanding and estimation of structural responses to earthquakes. By confirming the reliability of PBS-generated ground motions, this study supports the integration of advanced simulation techniques in performance-based earthquake engineering, contributing to the development of more resilient infrastructure and informed disaster risk reduction policies.
La valutazione del rischio sismico è fondamentale per garantire la resilienza e la sicurezza delle strutture nelle regioni soggette a terremoti. I metodi tradizionali di input sismico si basano spesso su accelerogrammi registrati, che possono non catturare completamente la variabilità e la complessità dei movimenti sismici del suolo. Le Simulazioni Basate sulla Fisica (PBS) offrono un'alternativa promettente, generando serie temporali dei movimenti sismici del suolo basate su modelli fisici dettagliati dei processi sismici. Queste simulazioni possono fornire rappresentazioni più accurate e specifiche degli eventi sismici, portando potenzialmente a un'analisi strutturale e a una progettazione migliorate. Questa tesi si propone di validare l'uso delle PBS per i movimenti sismici del suolo confrontando la loro efficacia con i segnali registrati attraverso l'analisi dinamica non lineare, concentrandosi specificamente sulla relazione tra l'Interstory Drift Ratio (IDR) e varie Misure di Intensità (IMs). Per raggiungere questo obiettivo, sono stati analizzati tre tipi di edifici in cemento armato—una struttura di 1 piano, 4 piani e 8 piani—utilizzando sia movimenti sismici registrati che simulati. Le IMs considerate includevano l'Accelerazione Massima del Suolo (PGA), la Velocità Massima del Suolo (PGV), l'Accelerazione Spettrale al periodo del primo modo (Sa(T1)), l'accelerazione spettrale media (Sa,avg), l'Intensità di Housner (HI) e l'Intensità di Arias (IA). Le analisi dinamiche non lineari (NLDAs) sono state eseguite per valutare le risposte IDR degli edifici in diversi scenari sismici. I risultati indicano che le PBS forniscono previsioni consistenti e affidabili dell'IDR rispetto ai movimenti sismici registrati, in particolare per PGV, Sa(T1), Sa,avg e HI. Queste IMs hanno dimostrato pendenze, intercette e deviazioni standard simili, suggerendo che le PBS possono replicare efficacemente la risposta strutturale osservata nei segnali registrati. Al contrario, PGA e IA hanno mostrato maggiori discrepanze, indicando che possono essere meno efficaci per l'uso nelle valutazioni sismiche quando derivate da dati simulati. In generale, questa ricerca valida l'applicazione delle PBS nell'analisi sismica, evidenziando il loro potenziale per migliorare la comprensione e la stima delle risposte strutturali ai terremoti. Confermando l'affidabilità dei movimenti sismici generati da PBS, questo studio supporta l'integrazione di tecniche di simulazione avanzate nell'ingegneria sismica basata sulle prestazioni, contribuendo allo sviluppo di infrastrutture più resilienti e a politiche di riduzione del rischio di disastri più informate
Engineering validation of physics-based simulated accelerograms for seismic non-linear dynamic analysis of structures
PAPA, ENIAS
2023/2024
Abstract
Seismic risk assessment is critical for ensuring the resilience and safety of structures in earthquake-prone regions. Traditional methods of seismic input often rely on recorded accelerograms, which may not fully capture the variability and complexity of earthquake ground motions. Physics-Based Simulations (PBS) offer a promising alternative, generating ground motion time series based on detailed physical models of earthquake processes. These simulations can provide more accurate and site-specific representations of seismic events, potentially leading to improved structural analysis and design. This thesis aims to validate the use of PBS for seismic ground motions by comparing their effectiveness with recorded signals through non-linear dynamic analysis, specifically focusing on the relationship between Interstory Drift Ratio (IDR) and various Intensity Measures (IMs). To achieve this goal, three types of reinforced concrete buildings—a 1-storey, 4-storey, and 8-storey structure—were analyzed using both recorded and simulated ground motions. The IMs considered included Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), Spectral Acceleration at the first-mode period (Sa(T1)), average spectral acceleration (Sa,avg), Housner Intensity (HI), and Arias Intensity (IA). The non-linear dynamic analyses (NLDAs) were performed to evaluate the IDR responses of the buildings under different seismic scenarios. The results indicate that PBS provide consistent and reliable predictions of IDR when compared to recorded ground motions, particularly for PGV, Sa(T1), Sa,avg, and HI. These IMs demonstrated similar slopes, intercepts, and standard deviations, suggesting that PBS can effectively replicate the structural response observed in recorded signals. In contrast, PGA and IA showed greater discrepancies, indicating that they may be less effective for use in seismic assessments when derived from simulated data. Overall, this research validates the application of PBS in seismic analysis, highlighting their potential to enhance the understanding and estimation of structural responses to earthquakes. By confirming the reliability of PBS-generated ground motions, this study supports the integration of advanced simulation techniques in performance-based earthquake engineering, contributing to the development of more resilient infrastructure and informed disaster risk reduction policies.| File | Dimensione | Formato | |
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Descrizione: Master Thesis on Engineering validation of physics-based simulated accelerograms, for seismic non-linear dynamic analyses of structures
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https://hdl.handle.net/10589/223493