The main objective of this thesis work is to research new approaches to the structural analysis of dry-stone false dome constructions, which are widespread in the Mediterranean area. In particular, in the "Valle d'Itria" region of central Apulia, it manifests itself in the form of trulli. This structural typology has ancient origins deriving from the Tholos tombs of Mycenae, built during the Late Bronze Age (c. 1200 - 500 B.C.), and has been handed down to the present day thanks to the marked construction wisdom of the so-called "mastri casellari". Despite their widespread use in the area, they are still little studied from the point of view of structural safety; there are a few works in the literature dealing with the statics of such constructions subjected only to gravitational loads, but approaches inherent to the seismic analysis of such structures are almost completely absent. Therefore, in the present thesis, we set out to investigate the seismic behavior of these constructions until collapse. To this end, a series of nonlinear static (push-over) analyses were conducted using a discrete element code (DEM) called 3DEC. This refined representation of the model made it possible to derive a series of useful information on the collapse modes of the false dome under study, useful in order to identify some of the possible collapse mechanisms manifested by constructions of this type. This made it possible to treat this type of construction by means of the simplified approaches typical of ordinary masonry construction (kinematic analysis). The results of the analyses turn out to be more consistent with the real collapse modes of such structures, as well as less conservative from the verification point of view, than those provided by the other approaches in the literature. Despite the complexity of the problem, they are shown to be encouraging for further development in the future.
Il presente lavoro di tesi si pone come principale obiettivo la ricerca di nuovi approcci all’analisi strutturale delle costruzioni a falsa cupola in pietra a secco, molto diffuse nell’area mediterranea. In particolare, nella regione della Valle d’Itria in Puglia centrale, si manifesta sottoforma di trulli. Tale tipologia strutturale ha antiche origini derivanti dalle tombe a Tholos di Micene, costruite durante la tarda età del bronzo (1200 – 500 a.C. circa) e si è tramandata sino ad oggi grazie alla spiccata sapienza costruttiva dei cosiddetti “mastri casellari”. Nonostante la vasta diffusione sul territorio, essi risultano essere tuttora poco studiati dal punto di vista della sicurezza strutturale; in letteratura sono presenti alcuni lavori che trattano la statica di tali costruzioni soggette ai soli carichi gravitazionali, ma sono quasi del tutto assenti approcci inerenti all’analisi sismica di tali strutture. Pertanto, nel presente lavoro di tesi, ci si è posti il problema di indagare il comportamento sismico di queste costruzioni fino al collasso. A tale scopo si sono condotte una serie di analisi statiche non lineari (push-over) utilizzando un codice agli elementi distinti (DEM) denominato 3DEC. Tale rappresentazione raffinata del modello ha consentito di ricavare una serie di informazioni utili sulle modalità di collasso della falsa cupola oggetto di studio, utili al fine di individuare alcuni tra i possibili meccanismi di collasso manifestabili da costruzioni di tale tipologia costruttiva. Questo ha permesso di trattare questa tipologia di costruzioni per mezzo degli approcci semplificati tipici delle costruzioni in muratura ordinaria (analisi cinematica). I risultati delle analisi risultano essere più coerenti con le reali modalità di collasso di tali strutture, oltre che meno conservativi dal punto di vista delle verifiche, rispetto a quelli forniti dagli altri approcci presenti in letteratura. Nonostante la complessità del problema, essi si mostrano incoraggianti per ulteriori sviluppi futuri.
NUOVI APPROCCI ALL'ANALISI STRUTTURALE DELLE COSTRUZIONI A TRULLO
LEOGRANDE, MASSIMO
2022/2023
Abstract
The main objective of this thesis work is to research new approaches to the structural analysis of dry-stone false dome constructions, which are widespread in the Mediterranean area. In particular, in the "Valle d'Itria" region of central Apulia, it manifests itself in the form of trulli. This structural typology has ancient origins deriving from the Tholos tombs of Mycenae, built during the Late Bronze Age (c. 1200 - 500 B.C.), and has been handed down to the present day thanks to the marked construction wisdom of the so-called "mastri casellari". Despite their widespread use in the area, they are still little studied from the point of view of structural safety; there are a few works in the literature dealing with the statics of such constructions subjected only to gravitational loads, but approaches inherent to the seismic analysis of such structures are almost completely absent. Therefore, in the present thesis, we set out to investigate the seismic behavior of these constructions until collapse. To this end, a series of nonlinear static (push-over) analyses were conducted using a discrete element code (DEM) called 3DEC. This refined representation of the model made it possible to derive a series of useful information on the collapse modes of the false dome under study, useful in order to identify some of the possible collapse mechanisms manifested by constructions of this type. This made it possible to treat this type of construction by means of the simplified approaches typical of ordinary masonry construction (kinematic analysis). The results of the analyses turn out to be more consistent with the real collapse modes of such structures, as well as less conservative from the verification point of view, than those provided by the other approaches in the literature. Despite the complexity of the problem, they are shown to be encouraging for further development in the future.I documenti in UNITESI sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/20.500.14253/83391