Abstract: According to the monitoring data over consecutive years for the seabed where submarine pipeline is from Cezi Island to Zhenhai, the results indicate seriously scouring phenomenon. For the purpose of making analysis about human activity influence, a two-dimensional numerical model was set up to simulate hydrodynamics and sediment environment of the Hangzhou Bay with Delft3D. This model had been calibrated and validated with observed data of tidal level, currents and suspended sediment concentration. The results show that the reclamation in Xinhongkou of Zhenhai and Jintang Bridge have a great impact on the seabed scouring of the landing position in Zhenhai. The results also show that the water-blocking effect of Jintang Bridge could aggravate the seabed scouring of the slope position in scouring channels, and that the seabed scouring of the extension position in deep pools is closely related with the main navigable hole of Jintang Bridge.

Key words: submarine pipeline, numerical simulation, seabed scouring and silting, development activity influence, Delft3D