Early Form Finding Techniques of Sergio Musmeci revisited

While Pier Luigi Nervi (1892-1979) and Riccardo Morandi (1902-1989) are two prominent names in the history of Italian structural engineering, a third, sometimes lesser known, predecessor of modern structural design should be given equal recognition. Sergio Musmeci (1926-1981), once an apprentice to the prior two designers, is noteworthy for his ability to design and construct continuous shells with unprecedented shapes well ahead of his time. He understood the importance of minimizing area while maximizing structural function in shells as early as the 1960’s. Musmeci’s Basento Viaduct in Potenza, Italy was built in 1969, and is a historical example of this structural efficiency. The concrete bridge has four 70 meter spans for a total length of 280 meters. The bridge deck is supported by a 30 cm to 1.2m thick concrete shell surface, the most interesting feature of the bridge, which alternates between convex and concrete curves to form the four arches. What is most intriguing about Musmeci is his understanding and manipulation of physical, numerical and analytical methods of form finding to achieve his design intent. This paper investigates Sergio Musmeci’s previous experience leading to the Basento Viaduct project, analyzes his modeling and testing techniques of the time, and revisits and discusses the shape generation of the three dimensional structural surface structure using contemporary numerical form finding techniques. In addition, this paper aims to provide an example of how revisiting historic structures can influence the design of contemporary and future thin shell bridge structures.