Design aspects of the AB prototype in the Qiandao Lake

Abstract Submerged Floating Tunnel, also known as Archimedes Bridge, appears to be a very suitable technical solution for waterway crossings. In spite of it, no SFT has been constructed yet in the world, probably due to the total lack of experimental data on the actual behaviour of SFTs under both traffic and environmental actions, such as currents, waves and earthquakes. The scope to fill the gap between theory and reality can be pursued only by the construction of a full-scale prototype of SFT. At this aim, the SIJLAB (Sino-Italian Joint Laboratory of Archimedes Bridge), a joint venture involving Italian and Chinese institutions, has carried out the design of the first SFT (Archimedes Bridge) prototype in the World, to be fabricated and erected in the Qiandao Lake (People’s Republic of China). This paper deals with the description of the various aspects faced in the design of the Archimedes Bridge prototype. The features of the selected location and the structural scheme, together with all the design requirements and design phases and outputs, are illustrated. The structural analyses aimed at investigating the prototype behaviour under the environmental loads and selecting the most suitable cable system configuration are described and the obtained results are discussed. The conception and the design of the constructional details, such as the anchoring connections, the internal and end joints, the windows are presented. The technical solution for the foundation of the anchoring system is illustrated. Finally, the fabrication and erection procedures are briefly described, they representing an important aspect of the design of such a revolutionary technological system.