Knowledge, preservation principles and intervention, in the architectural-archaeological restoration of My Son.

The 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.