1,721,037 research outputs found
Understanding and modelling crack patterns in a masonry farmhouse
No full textThe stress analysis of a masonry farmhouse in Northern Italy is investigated, the oldest part of which dates back to the 17th century. The building has experienced severe structural problems, which are likely to be due to differential settlements. An extensive crack pattern, including vertical and inclined passing cracks, can be observed. A static monitoring system was installed to track the evolution of the major cracks for a duration of 18 months. An attempt at interpreting the crack pattern was carried out by developing a detailed finite element model, to which suitable boundary conditions were prescribed to model presumed ground settlements. The main cracks existing in the building were also included in the model, to assess the current conditions of the building. The tensile stresses in some parts of the building are found to be sufficiently high to induce further crack growth. Eventually, the vulnerability of the building to possible seismic actions was assessed. The numerical results are
used to propose a simple retrofitting strategy for the building
Indagini strutturali sulla Basilica di Santa Maria Novella
No full textThe present work describes the preliminary results of structural analyses carried out on a finite element model of the Basilica of Santa Maria Novella in Florence, aiming at assessing the current conditions of the Basilica and interpreting the surveyed crack pattern. The information gathered in a previous survey campaign (exact geometry of the vaults, crack pattern, and out-of-plumb of the columns and the walls) were employed to define a numerical model that matches the salient features of the real geometry of the Basilica, despite some simplifying assumptions. So far, linear elastic analyses taking only the self-weight of the structural elements into account, were carried out. Despite these limitations, the faults observed in the vaults of the lateral naves and in the perimeter of the transept could be explained. The agreement between numerical predictions and cracks detected in other parts of the Basilica, such as the vaults of the central nave and the transversal walls above this nave, is less satisfactory. Future analyses will include the effects of ground settlements and the out-of-plumb of the pillars of the central nave
IL RESTAURO DELLA CHIESA DI SAN NICOLA A MESOPOTAM: UN INTERVENTO IN CHIAROSCURO
No full textIn questo lavoro si discute l’efficacia degli interventi eseguiti sulla chiesa bizantina di S. Nicola a Mesopotam, in Albania, che avevano lo scopo di consolidare l’edificio riportandolo, al contempo, ad una presunta configurazione pre-settecentesca. Sono stati sviluppati due modelli ad elementi finiti della chiesa così com’era fino al 2009 e nelle sue attuali condizioni. I modelli cercano di riprodurre quanto più fedelmente possibile le principali caratteristiche geometriche dell’edificio, tenendo conto della natura macroscopicamente ortotropa dei materiali e delle principali fessure. I due modelli sono stati sottoposti ad analisi elastiche lineari, sotto l’azione del peso proprio e di carichi orizzontali equivalenti al sisma secondo la normativa italiana. I risultati numerici mostrano che, in presenza di sisma, le sollecitazioni nell’edificio crescerebbero notevolmente a causa dei discutibili interventi eseguiti. La rimozione di un contrafforte si rivela un’operazione, se non dannosa, quantomeno controversa
Knowledge, preservation principles and intervention, in the architectural-archaeological restoration of My Son.
No full textThe archaeological area of Mỹ Sơn is one of the most important architectural examples of the south East Asia. The site was discovered and cleaned from the jungle vegetation only at the end of the 19th cent, after centuries of complete abandonment.
The French were the only ones also as researchers, who took care of the Cham people who built Mỹ Sơn, through the work of Henry Parmentier, with archaeological excavations up to the half of the 20th cent.. The political and war events from the fifties to the sixties which continued in Vietnam did not allow the prosecution of the excavations.
The research was continued for a short period from 1982 to 1986 thanks to Vietnamese-Polish mission which restored some temples in Mỹ Sơn. This mission worked not only on the Mỹ Sơn site, but also in the most important Cham sites in the Vietnamese territory. From the nineties also Vietnamese researchers were interested on the Cham archaeology and architecture unfortunately their publication were in Vietnamese and their reports were difficult to be approached.
The Cham religious buildings were realised with brick masonry with very thin joints and at the end of the American/Vietnamese war most of them were reduced to ruins.
Vietnam country is now enjoying a very happy economical period with a large development of nearly all sectors; therefore the Vietnamese feel today a deep will of reconstruct their identity also through the valorisation of the cultural patrimony. Nevertheless the country is still rather weak from the point of view of history and theory of restoration, if compared to Europe.
In these last years the restoration of Cham buildings was carried out with new techniques and materials and reconstructions of missing parts according to the pre-existing style. The works were done following a way which belongs to the wishes of the Asiatic culture (e.g. it is enough to remember the reconstruction of the Japanese temples as a procedure adopted for centuries).
In several examples invasive techniques and inappropriate materials were adopted in Vietnam, which along the time have caused quick degradation of the new parts and amplification of the deterioration phenomena. Furthermore the peculiar construction technique with thin resin joints in the masonry does not allow the use of techniques familiar to the Europeans.
From 2003 thanks to a first convention (1999-2001) between UNESCO, Vietnam Ministry of Culture and the Fondazione Lerici a pilot project for excavation and conservation was started of a group of religious buildings partially at the state of ruins in Mỹ Sơn; they were classified by H. Parmentier with the letter G and were built between the 11th and 13th cent. he project developed up to now in Mỹ Sơn allows to answer to numerous open ions of historical and scientific character and to give the site a new value through the right conservation of some buildings
From 2000 the Dept of Structural Engineering (DIS) of the Politecnico of Milan thanks to Prof. L. Binda and her collaborators is actively involved in the characterisation of the original Cham materials, and the individuation of the original construction techniques, in the definition of the state of preservation and in the research and characterisation of compatible materials, in the proposal of a conservation project based on right methodologies and intervention techniques
Restoration of Hindu temples in Mỹ So’n, Viet Nam: experimental investigation, modelling and proposal for intervention
No full textThe archaeological site of Mỹ Sơn is located in central Vietnam and is characterized by the presence of several Hindu temples, many of which were heavily damaged during the Viet Nam war in the 1960s. The present work illustrates the results of experimental tests carried out on material samples taken from the temples, and describes the fundamental lines of the preservation project to be undertaken. Finite element models of some of the temples were set up, both at their presumable original state and at their current damaged conditions. The stress analyses of the original temples aimed to establish whether or not the self-weight alone might be the cause for the collapse of parts of the temples. Also, the damages induced by the bombs and the vegetation were taken into account, and the current stress conditions were determined. The FE models take the layered nature of masonry into account; different types of interactions between the masonry leaves were assumed in the analyses. Some conclusions on the safety of the temples in its past and current conditions are drawn; also, the influence of the models employed to describe the interaction between the different masonry layers is discussed
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