Precast buildings are widely adopted as industrial long-span structures, and their behaviour under seismic actions is still nowadays subject of research and investigations. In the last few years, critical behaviour of structural connections were observed during recent seismic events, due to wrong conception, design or application, causing as a consequence the loss of support of horizontal members and/or the collapse of the panels. The following thesis work investigates explicit retrofit interventions related to the connection systems, trying to mitigate the seismic risk associated to large industrial buildings. In particular, five different models of a representative large industrial cladded frame structure designed for soil type C for the site of L'Aquila are implemented. The first intervention concerns the post-installation of metallic brackets connecting the peripheral panel support columns with the frame elements. The second intervention introduces strengthening of roof-to-beam dowel connections, through metallic brackets fastened at the interface. The third intervention involves strengthening of the existing cladding panel connections by the alternative installation of folded plate devices (FPDs) or sliding connections. The modelling accuracy and structural reliability were assessed through gravitational analysis, while modal analysis was employed to define the dynamic structural behaviour and vibrational characteristics. Furthermore, non-linear static analyses were developed for both the initial model and the models with seismic retrofit measures based upon sophisticated non-linear modelling of connections and structural members. The results allow to quantify the efficiency of the different retrofit interventions and their combination in terms of strength and displacement capacity, highlighting the failure chain of each case. The work has been carried out as a part of the national research project RINTC (Implicit Risk of structures designed according to the NTC), commissioned and funded by the Italian Civil Protection Department, within the ReLUIS (the Italian Network of Earthquake Engineering University Labs) research programme and consortium.
Gli edifici prefabbricati sono ampiamente adottati come strutture industriali a lunga campata e il loro comportamento sotto azioni sismiche è ancora oggi oggetto di ricerche e indagini. Negli ultimi anni si è osservato un comportamento critico delle connessioni strutturali durante i recenti eventi sismici, a causa di errate concezioni, progettazioni o applicazioni, causando di conseguenza la perdita del supporto degli elementi orizzontali e/o il collasso dei pannelli. Il seguente lavoro di tesi indaga espliciti interventi di adeguamento relativi ai sistemi di connessione, cercando di mitigare il rischio sismico associato ai grandi edifici industriali. In particolare, vengono implementati cinque diversi modelli sulla base di una grande struttura portante industriale rivestita con pannelli e progettata per il suolo di tipo C per il sito dell'Aquila. Il primo intervento riguarda la post-installazione di staffe metalliche che collegano le colonne perimetrali di supporto dei pannelli con gli elementi del telaio. Il secondo intervento introduce il rafforzamento dei collegamenti spinottati tra il tetto e la trave, attraverso staffe metalliche fissate all'interfaccia. Il terzo intervento prevede il rafforzamento dei collegamenti dei pannelli di rivestimento esistenti mediante l'installazione alternativa di dispositivi a piastre piegate (FPD) o collegamenti scorrevoli. L'accuratezza della modellazione e l'affidabilità strutturale sono state valutate attraverso l'analisi gravitazionale, mentre l'analisi modale è stata utilizzata per definire il comportamento strutturale dinamico e le caratteristiche vibrazionali. Inoltre, sono state sviluppate analisi statiche non lineari sia per il modello iniziale che per i modelli con interventi di adeguamento sismico basate su sofisticati modelli non lineari di connessioni e componenti strutturali. I risultati consentono di quantificare l'efficienza dei diversi interventi di adeguamento e la loro combinazione in termini di resistenza e capacità di spostamento, evidenziando la catena di guasto di ciascun caso. Il lavoro è stato realizzato nell'ambito del progetto di ricerca nazionale RINTC (Rischio Implicito delle Norme Tecniche per le Costruzioni Italiane), commissionato e finanziato dal Dipartimento della Protezione Civile Italiano, all'interno del programma di ricerca e consorzio ReLUIS (Rete dei Laboratori Universitari di Ingegneria Sismica).
Assessment of seismic retrofit interventions on a long-span precast industrial building by pushover analysis
Fadel Zaki Sous, Manuel
2022/2023
Abstract
Precast buildings are widely adopted as industrial long-span structures, and their behaviour under seismic actions is still nowadays subject of research and investigations. In the last few years, critical behaviour of structural connections were observed during recent seismic events, due to wrong conception, design or application, causing as a consequence the loss of support of horizontal members and/or the collapse of the panels. The following thesis work investigates explicit retrofit interventions related to the connection systems, trying to mitigate the seismic risk associated to large industrial buildings. In particular, five different models of a representative large industrial cladded frame structure designed for soil type C for the site of L'Aquila are implemented. The first intervention concerns the post-installation of metallic brackets connecting the peripheral panel support columns with the frame elements. The second intervention introduces strengthening of roof-to-beam dowel connections, through metallic brackets fastened at the interface. The third intervention involves strengthening of the existing cladding panel connections by the alternative installation of folded plate devices (FPDs) or sliding connections. The modelling accuracy and structural reliability were assessed through gravitational analysis, while modal analysis was employed to define the dynamic structural behaviour and vibrational characteristics. Furthermore, non-linear static analyses were developed for both the initial model and the models with seismic retrofit measures based upon sophisticated non-linear modelling of connections and structural members. The results allow to quantify the efficiency of the different retrofit interventions and their combination in terms of strength and displacement capacity, highlighting the failure chain of each case. The work has been carried out as a part of the national research project RINTC (Implicit Risk of structures designed according to the NTC), commissioned and funded by the Italian Civil Protection Department, within the ReLUIS (the Italian Network of Earthquake Engineering University Labs) research programme and consortium.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/214080