The Lectotype Optimization Study on Submerged Floating Tunnel Based Delphi Method

As a new underwater transport facilities used for crossing the strait, lakes and rivers, the submerged floating tunnel (SFT) has advantages in the wide range of construction, adaptable and little impact on environmental. This paper describes and compares the various types of the submerged floating tunnel, lists the different forms of material and the layouts of the tethers of the tethered submerged floating tunnel, analyzes the advantages and disadvantages of different layouts of the tethers. Finally considering the geomorphological features of the Qiongzhou strait, this paper evaluates the expert advices by using Delphi method, gives the optimal line position of the Qiongzhou strait tunnel and appropriate selection of the submerged floating tunnel.