This thesis addresses the issue of seismic retrofitting of existing reinforced concrete buildings through the use of advanced seismic protection techniques. The work is based on the analysis of a real-world case study: the ‘Collegio Universitario Fazzini’ in Camerino (MC), a building dating from the early 1970s that was severely damaged by the 2016 Central Italy earthquake sequence. The first phase of the work focused on the structural assessment of the building (achieving Knowledge Level LC3) and the subsequent three-dimensional finite element modelling using SAP2000 software. Particular attention was paid to the interaction between the structural frame and the cladding, modelling the wall panels as equivalent struts in accordance with the rigorous guidelines of the recent draft of the new Eurocode 8 (FprEN 1998-1-2:2025). This approach highlighted the significant influence of non-structural elements on the lateral stiffness and dynamic characteristics of the building. Subsequently, the study focused on the design and technical comparison of two different retrofitting strategies: a hybrid base isolation system (comprising HDRB elastomeric isolators and sliding pads) and a system of external dissipative bracing fitted with viscous dampers. The final comparison highlighted that base isolation offers an extremely robust design solution that is largely unaffected by the inevitable uncertainties associated with modelling existing buildings. By contrast, the design of external energy-dissipating bracing – investigated using both simplified approaches and advanced Three-Element Models – was found to be heavily dependent on the precise estimation of the initial stiffness of the infill frame and the actual flexibility of the external bracing structure, making the design process significantly more complex.
La presente tesi affronta il tema dell’adeguamento sismico di edifici esistenti in calcestruzzo armato mediante l’impiego di tecniche di protezione sismica avanzata. Il lavoro si sviluppa attraverso l’analisi di un caso studio reale: il "Collegio Universitario Fazzini" di Camerino (MC), un edificio risalente ai primi anni '70 gravemente danneggiato dalla sequenza sismica del Centro Italia del 2016. La prima fase del lavoro si è concentrata sul percorso conoscitivo della struttura (raggiungendo un Livello di Conoscenza LC3) e sulla successiva modellazione tridimensionale agli elementi finiti tramite il software SAP2000. Particolare attenzione è stata dedicata all'interazione telaio-tamponatura, modellando i pannelli murari come puntoni equivalenti secondo le rigorose direttive della recente bozza del nuovo Eurocodice 8 (FprEN 1998-1-2:2025). Tale approccio ha evidenziato la significativa influenza degli elementi non strutturali sulla rigidezza laterale e sulle caratteristiche dinamiche del fabbricato. Successivamente, lo studio si è focalizzato sulla progettazione e sul confronto tecnico di due differenti strategie di adeguamento: un sistema di isolamento sismico ibrido alla base (composto da isolatori elastomerici HDRB e slitte a scorrimento) e un sistema di controventi dissipativi esterni dotati di smorzatori viscosi. Il confronto finale ha evidenziato come l’isolamento alla base offra una soluzione progettuale estremamente robusta e poco sensibile alle inevitabili incertezze legate alla modellazione degli edifici esistenti. Al contrario, la progettazione dei controventi dissipativi esterni – indagata sia con approcci semplificati che con modelli avanzati a tre elementi (Three-Element Model) – è risultata fortemente condizionata dall'esatta stima della rigidezza iniziale del telaio tamponato e dalla reale flessibilità della struttura esterna di contrasto, rendendo il suo iter progettuale significativamente più complesso.
Soluzioni innovative a confronto per l'adeguamento di edifici esistenti in c.a.
MARCACCIO, FRANCESCO
2025/2026
Abstract
This thesis addresses the issue of seismic retrofitting of existing reinforced concrete buildings through the use of advanced seismic protection techniques. The work is based on the analysis of a real-world case study: the ‘Collegio Universitario Fazzini’ in Camerino (MC), a building dating from the early 1970s that was severely damaged by the 2016 Central Italy earthquake sequence. The first phase of the work focused on the structural assessment of the building (achieving Knowledge Level LC3) and the subsequent three-dimensional finite element modelling using SAP2000 software. Particular attention was paid to the interaction between the structural frame and the cladding, modelling the wall panels as equivalent struts in accordance with the rigorous guidelines of the recent draft of the new Eurocode 8 (FprEN 1998-1-2:2025). This approach highlighted the significant influence of non-structural elements on the lateral stiffness and dynamic characteristics of the building. Subsequently, the study focused on the design and technical comparison of two different retrofitting strategies: a hybrid base isolation system (comprising HDRB elastomeric isolators and sliding pads) and a system of external dissipative bracing fitted with viscous dampers. The final comparison highlighted that base isolation offers an extremely robust design solution that is largely unaffected by the inevitable uncertainties associated with modelling existing buildings. By contrast, the design of external energy-dissipating bracing – investigated using both simplified approaches and advanced Three-Element Models – was found to be heavily dependent on the precise estimation of the initial stiffness of the infill frame and the actual flexibility of the external bracing structure, making the design process significantly more complex.| File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12075/27729