The motion responses, mooring tensions, and submergence depth are the dominant factors for the arrangement of the Submerged Floating Tunnel (SFT) subjected to waves. Generally, the maximum values of motion responses, mooring tensions, and absolute submergence depth are mainly focused on. In the present study, experiments are implemented to measure the motion responses and mooring tensions of the SFT with different mooring patterns and submergence depths under waves with different characteristic wave heights and periods. In order to evaluate the arrangement of the SFT more effectively and comprehensively, besides the maximum values, several new characteristic parameters are introduced. Such parameters account for the motion responses in the frequency domain, the uniformity of the tension distribution, the length of time during which the cable reaches a relaxed condition during wave action, the KC number, the dimensionless period, the wave height, and the submergence depth. The results from the optimization analysis show the following: according to the characteristic values of motion responses and mooring tensions, the pattern of diagonal cables is better than that of diagonal cables + vertical cables; and within the range of the present experiments, there are optimal dimensionless parameters—the dimensionless submergence depth d₀/L_P ≥ 0.15, the KC number ≤ 0.8, or the dimensionless wave height Hs/d₀ ≤ 0.10—for the condition of which the dynamic responses and mooring tensions vary slightly.

This paper using WRF mesoscale atmospheric model, the reanalysis wind field data provided by ncep global forecast field as the initial condition and boundary condition with time, calculated the wind field with sufficient precision, provided the driving wind field for the wave numerical calculation, calculated the corresponding wave field with model SWAN, and simulated the wind wave process caused by a cold wave wind in the Bohai sea area from 5 to 7 November 2015. The calculated model was verified by the measured wind and waves data at the stations of Huanghua and Dongying. The results show that the simulation values of wind and wave elements are in good agreement with the measured values. The model can reproduce the characteristics of wind and wave distribution during the cold tide in Bohai Sea.