Study On Loads Combination And Effect Analysis Of Submerged Floating Tunnel

The submerged floating tunnel (SFT) is a new symbolization of crossing tunnel conception, which is kept at some depth below the water surface by the balance between the downward load and the buoyancy force and with the aid of a specialized support system. It is an innovative traffic structure used to cross a strait, a bay, a fiord, a lake or other appropriate waterways. The advantages of the SFT as:The total length of an SFT is noticeably shorter than that of any ordinary submarine tunnel; Lower environmental impact and improving the environmental protection; The site selection of SFT is in high degree of freedom. There are potential application values in the construction of connecting structures between the islands and the mainland, the bay crossing channels and the off shore buildings. These benefits are so obvious that it rendered the SFT becoming increasingly a new researching task in tunnel specially.The concrete tasks were accomplished in each part as follows:1. This dissertation summarized the environmental where the SFT constructing and classified the loads which effects on the SFT.2. Simply introduced the theory of wave, analysis the calculating method of the wave force and current force which act on the SFT, and calculating the current force of SFT with steady flow theory.3. Established the simple calculate3D finite element model of SFT with the finite element soft ANSYS. Analysis the static response of SFT with ellipse (η=0.3) cross section、ellipse(η=0.4)cross section、ellipse(η=0.5)cross section、ellipse(η=0.6) cross section、ellipse(η=0.7)cross section and circle cross section and polygon cross section in different water velocity、cable angle and submerging depth.4. Simulated the circumferential flow field of SFT with the fluid calculating soft FLUENT, and analysis the pressure field and the velocity of the ellipse (η=0.3) cross section、ellipse(η=0.4)cross section、ellipse(η=0.5)cross section、ellipse(η=0.6) cross section、ellipse (η=0.7)cross section and circle cross section and polygon cross section in different water velocity.