Models of urban development: the portico of the Alemanni in Bologna

The aim of the study is to discover evolutionary rules of the city in order to maintain the integrity and consistency of places. These "project rules" were sought in growth patterns of cities which have been emerging during the course of its historical development. The urban development of Bologna is characterized by the strong signs formed outside the city walls during the eighteenth and seventeenth century. These are the two arcades connecting the places where the ramparts stood at the Sanctuary of San Luca and the churches of San Gregorio and Alemanni. The "portico of Alemanni", completed in 1631, is today recognizable only visually, because it is incorporated into the urban blocks. In contrast, the portion of "portico of San Luca" hill, which was completed one hundred years later with the construction of arcade of Meloncello, remains a strong and distinct sign that welcomes people arriving to Bologna from North and West. The singularity of these extra-urban arcaded structures is the most striking aspect. Furthermore, the study concerns how these structures are a reference for the development of the extra-moenia city. The development of the city was focusing on 3 key issues: the economy, a reference to a "standard" and a method of construction. The urban plans, generally, have proposed a development organized without these characters, which then has breached the rules of expansion, where new buildings are disconnected from the existing city. It is in the urban sections of arcades leading to the "Maria Lacrimosa degli Alemanni" church and the sanctuary of "San Luca" that has developed the city adjacent areas. In some cases, the portico is taken as constructive principle, and is incorporated in a building with several floors and has other functions in addition to coverage of walking trails. In other cases, the arcade has led to the reorganization of adjacent areas according to a form that successive plans have never recognized. The study of suburban arcades of the XVII and XVIII century and their mode of development returns a growth model whose interpretation provides a key of interpretation of ways to design urban development in our time. On the other side, these architectures have been considered as independent elements rather than elements leading the development of the city. With this study, the city is studied by surveying, drawings and photographs that sll togheter contribute to return its representation. The graphics processing complete the conceptual and analytical framework and prove evidence of connection between reading and project, and therefore, they can be considered as useful elements of analysis and intervention on the existing city. The goal is to go beyond the limits of tools based exclusively on "morphological stereotypes" forms of the past. Visual and perceptual aspects characterizing the "rules of the game" have been considered the for these parts of the city. And taking into account the changing of the city.