Masonry Structure is one of the oldest and most widely used structural systems for building construction around the world. Past earthquakes around the globe proved the vulnerability of this structural system against the earthquake. Hence many researchers have been working and revealing new techniques to improve the seismic resistance of masonry structures. For this reason, by inspecting all feasible retrofitting techniques could find that still there are some gaps in techniques that are used to improve the in-plane behavior and out-of-plane behavior of masonry walls. For the improvement of In-Plane behavior, the reinforced plaster is the most common one but there are limited advanced and sufficient studies on the behavior of this methodology, especially on the effects of plaster thickness and the anchoring system for attachment of reinforced plaster to the masonry wall. Furthermore, to improve the out-of-plane resistance of a masonry wall, and obtain the box behavior, a new retrofitting technique(helicoidal bar) was considered because of its low invasivity and good compatibility with existing masonry. This study focus on the experimental and numerical analysis to obtain a better insight into the performance of those techniques. Hence, for the in-plane improvement, 14 specimens were made and tested under diagonal cyclic loading. Additionally, in order to have a clear vision of the helicoidal bar, first, several tests were performed on a single anchor considering different geometrical parameters, then the global behavior of the t-wall and u-wall retrofitted by Helicoidal bar and Injected anchors were examined. Several Parametric studies were conducted to assess all possible phenomena and structural behavior of the aforementioned techniques through FEM modeling. The numerical modeling was performed by utilizing ABAQUS software. Outcomes revealed the effectiveness of reinforced plaster and the novel anchoring systems on the seismic performance of masonry structures.
La struttura in muratura è uno dei sistemi strutturali più antichi e ampiamente utilizzati per la costruzione di edifici in tutto il mondo. I terremoti passati in tutto il globo hanno dimostrato la vulnerabilità di questo sistema strutturale contro i terremoti. Pertanto, molti ricercatori hanno lavorato per rivelare nuove tecniche al fine di migliorare la resistenza sismica delle strutture in muratura. Tuttavia, ispezionando tutte le tecniche di retrofitting fattibili, si è scoperto che ci sono ancora alcune lacune nelle tecniche utilizzate per migliorare il comportamento in piano e fuori piano delle pareti in muratura. Per quanto riguarda il miglioramento del comportamento in piano, l’uso di intonaco rinforzato è il più comune, ma ci sono studi limitati e avanzati sul comportamento di questa metodologia, soprattutto sugli effetti dello spessore dell’intonaco e del sistema di ancoraggio per il fissaggio dell’intonaco rinforzato alla parete in muratura. Inoltre, per migliorare la resistenza fuori piano di una parete in muratura e ottenere un comportamento a “scatola”, è stata considerata una nuova tecnica di retrofitting (barra elicoidale) a causa della sua bassa invasività e della buona compatibilità con la muratura esistente. Questo studio si concentra sull’analisi sperimentale e numerica per ottenere una migliore comprensione delle prestazioni di queste tecniche. Per il miglioramento in piano, sono stati realizzati 14 campioni e testati sotto carico ciclico diagonale. Inoltre, per avere una visione chiara della barra elicoidale, sono stati eseguiti diversi test su un singolo ancoraggio considerando diversi parametri geometrici. Successivamente, è stato esaminato il comportamento globale delle pareti “t” e “u” rinforzate con barra elicoidale e ancoraggi iniettati. Sono stati condotti diversi studi parametrici per valutare tutti i possibili fenomeni e il comportamento strutturale delle tecniche sopra menzionate attraverso la modellazione agli elementi finiti (FEM). La modellazione numerica è stata eseguita utilizzando il software ABAQUS. I risultati hanno dimostrato l’efficacia dell’intonaco rinforzato e dei nuovi sistemi di ancoraggio per la resistenza sismica.
Seismic retrofitting of masonry structures with post-installed systems
VAFA, NAVID
2023/2024
Abstract
Masonry Structure is one of the oldest and most widely used structural systems for building construction around the world. Past earthquakes around the globe proved the vulnerability of this structural system against the earthquake. Hence many researchers have been working and revealing new techniques to improve the seismic resistance of masonry structures. For this reason, by inspecting all feasible retrofitting techniques could find that still there are some gaps in techniques that are used to improve the in-plane behavior and out-of-plane behavior of masonry walls. For the improvement of In-Plane behavior, the reinforced plaster is the most common one but there are limited advanced and sufficient studies on the behavior of this methodology, especially on the effects of plaster thickness and the anchoring system for attachment of reinforced plaster to the masonry wall. Furthermore, to improve the out-of-plane resistance of a masonry wall, and obtain the box behavior, a new retrofitting technique(helicoidal bar) was considered because of its low invasivity and good compatibility with existing masonry. This study focus on the experimental and numerical analysis to obtain a better insight into the performance of those techniques. Hence, for the in-plane improvement, 14 specimens were made and tested under diagonal cyclic loading. Additionally, in order to have a clear vision of the helicoidal bar, first, several tests were performed on a single anchor considering different geometrical parameters, then the global behavior of the t-wall and u-wall retrofitted by Helicoidal bar and Injected anchors were examined. Several Parametric studies were conducted to assess all possible phenomena and structural behavior of the aforementioned techniques through FEM modeling. The numerical modeling was performed by utilizing ABAQUS software. Outcomes revealed the effectiveness of reinforced plaster and the novel anchoring systems on the seismic performance of masonry structures.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/220152