All'interno delle mura. Progetti e strategie per la struttura urbana minima di Castelsantangelo sul Nera

This thesis looks at Castelsantangelo sul Nera, a fortified village located in the heart of the Sibillini Mountains, on the border between Marche and Umbria. The territory analysed is located in an area of high seismic risk and has been hit in cyclical phases by strong earthquakes that have marked its history. The village and the surrounding territories, already subject to the phenomenon of abandonment, were hit by the 2016 earthquake that caused extensive damage and led to the closure of several inhabited areas. The remaining population of Castelsantangelo has been living for five years in the Soluzioni Abitative in Emergenza (SAE, Emergency Housing Solutions) located near the uninhabitable urban settlements. The municipality is divided into 7 fractions, the main one of which is a fortified system; in the past, it was the place where the inhabitants of the surrounding lands took refuge in case of enemy incursion. In the coming years, the reconstruction project of the municipality presented in the August 2021 as Piano Attuativo (Construction Plan) will be realised. Starting from these premises and working alongside the Construction Plan, the thesis aims to develop the basis for a reconstruction project for the castle village capable of assimilating past experiences and withstanding future emergencies. The project presented starts from an in-depth study of Castelsantangelo sul Nera and the surrounding area. A series of analyses were carried out both of the territory, from a geographical and orographical point of view, and of the buildings present in the feactions through the study of historical land registers, traditional local construction techniques and the morphological conformation of each fraction. The thesis, which focuses on the wall system of the fraction of Capoluogo, is part of a more general strategy that takes into consideration all the fractions of the municipality and the economic-social relations between them and with the surrounding territory. What emerges from the analysis is the inability of these places to withstand the earthquake first of all in physical terms and consequently in socio-economic terms: 98% of the buildings have collapsed or are uninhabitable, the technological infrastructures are out of use and the accesses to the city walls are blocked as a result of the collapse of the gates and portions of the walls themselves. The forced abandonment of recent years has also led to an exponential increase in the degradation of the fortified village's architectural artefacts and the loss of a local memory and social identity. The project is therefore developed starting from the concept of Struttura Urbana Minima (SUM, Minimum Urban Structure), in order to constitute a fortified village capable of preserving its main organs that allow it to function and be accessible. In this way, a process of preservation of the settlement's essential productive, economic and social systems is triggered, and the village within the walls is guaranteed to be a place to live. The project, with these prerogatives, takes shape on several levels, first and foremost through a system of "intra moenia" accessibility that guarantees continuous walkability, escape routes and safe areas. The routes interpenetrate with the existing systems and with the city walls in a process that aims to preserve and enhance the existing state of the arts. The integration of functional structures capable of withstanding an earthquake and of being converted in the event of an emergency in such a way as to constitute a flexible system is also envisaged. The project also proposes the introduction of productive functions at an agricultural level in long-abandoned areas within the walls; this aims not only to create a new economic system, but also to make degraded areas of the Urban Walls visible and visitable by triggering a process of conservation of the historic walls.

La tesi pone lo sguardo su Castelsantangelo sul Nera, un borgo fortificato situato nel cuore dei Monti Sibillini, al confine tra Marche e Umbria. Il territorio si trova in un’area ad alto rischio sismico ed è stato colpito a fasi cicliche da forti terremoti che ne hanno segnato la storia. Il borgo e i territori circostanti, già sottoposti al fenomeno dell’abbandono, sono stati colpiti dal sisma del 2016 che ha causato ingenti danni e ha portato alla chiusura di diverse aree abitate. La popolazione di Castelsantangelo rimasta vive da 5 anni nelle Soluzioni Abitative in Emergenza (Sae) poste in prossimità degli insediamenti urbani inagibili. Il comune è diviso in 7 frazioni di cui la principale è un sistema fortificato; esso era il luogo in cui nel passato gli abitanti delle terre circostanti si rifugiavano in caso di incursione nemica. La tesi, che si focalizza sul sistema murario della frazione di Capoluogo, si innesta su una strategia più generale che tiene in considerazione tutte le frazioni del comune, le relazioni economico-sociali tra di esse e con il territorio circostante, e i piani di intervento pubblicati dal comune tra il 2020 e il 2021. Il progetto si sviluppa quindi partendo dal concetto di Struttura Urbana Minima, per costituire un borgo fortificato capace di conservare i propri organi principali che ne permettano il funzionamento e l’accessibilità. In questo modo si innesca un processo di conservazione dei sistemi produttivi, economici e sociali essenziali dell’insediamento e si garantisce agli abitanti il borgo all’interno delle mura come luogo dell’abitare. Il progetto, con queste prerogative, prende forma su più livelli, in primo luogo attraverso un sistema di accessibilità “intra moenia” che garantisce una percorribilità continua, vie di fuga e aree sicure. I percorsi si compenetrano con i sistemi attuali e con le Mura Urbiche in un processo che mira a conservare e valorizzare lo stato di fatto. Si prevede poi l’integrazione di strutture funzionali capaci di resistere al terremoto e di essere convertite in caso di emergenza in modo tale da costituire un sistema flessibile e, oltre a queste anche di funzioni produttive.