Structural Interpretation of "Armate travi" in N-E Italy through the Historical Treatises

The study aims to clarify the geometrical configuration and the behaviour of a particular typology of wooden beams. Historically double framework wooden floors have covered wide rooms or loggias; frequently the principal beams were made up of more wooden elements assembled together to reach considerable length. The technology of «trave armata» allows to cover large spaces – up to 12/16 meters – by using small, shaped assembled and vertical nailed elements in order to obtain a single beam. This technology spread over a large area in northern Italy between XV and XVI centuries. There are a lot of examples in buildings (palaces, castles, loggias) along the Adige's path, in Trento, Verona, Mantova and Ferrara (Badalini and Dandria 2009), but also in the large area among Emilia and Lombardia and other singular cases in Firenze. Others examples of composite beams were studied in Provence (Bouticourt 2008) and some indications suggest an extention of this technology further the entire alpine arch. In addition the european historical treatises confirm that this method was internationally known. In spite of they are quite common, this kind of structures hasn't been investigate in a specific way, except for the F.E.M. analisys applied in Ferrara for reconstructing the distribution of stress end strains (Fabbri 2005), and it hasn't been elaborated an appropriate calculation procedure to verify the structure. The aim of this study is to connect together the geometrical and dimensional data come from the detailed surveys of most significant floors with the informations derived from treatises in order to comprehend the assembling procedure, the role of geometrical and static characteristics and to evaluate them.