Abstract:  Wave load is one of the main environmental loads faced by the largescale wide crosssectional submerged floating tunnel (SFT) during sinking. To investigate the relationship between the wave loads of the largescale wide SFT tube and environmental parameters and geometric dimensions, a twodimensional numerical model of the tube is established based on the computational fluid dynamics(CFD) software FLUENT. By taking the roundend and hexagonal sections as objects, the influence laws of the wave height, wave period, submerged depth, and section size on the wave loads acting on the largescale wide SFT tubes are discussed. The relationship between sectional size and wave diffraction coefficient is also examined. And the comparison with the results of circular sections based on the Morison formula is performed. The results show the following: (1) For the largescale wide crosssectional tubes with the ratio of transverse size to wavelength greater than 0.2, the CFD numerical simulation and diffraction theory are more suitable for wave load studies. (2) The horizontal/vertical forces and overturning moment for the roundend and hexagonal sectional tubes all increase with the increase of wave height and wave period. The wave forces corresponding to the two types of sections all increase to certain degrees when the central width becomes larger. And the significant increase of overturning moment is a key concern for the wide section. (3) Increasing the submerged depth is an important measure to reduce the wave overturning moment. When it reaches 30 m, the overturning moments corresponding to different section types and widths decrease to a smaller value. (4) The diffraction coefficients of the largescale wide SFT section are closely related to the sectional heightwideratio. When it increases, the horizontal/vertical diffraction coefficient increases/decreases.

Key words: submerged floating tunnel, large-scale wide section, wave loads, computational fluid dynamics numerical simulation, overturning moment