Numerical Study on the Effect of Breakwater Construction on Tidal Flow and Sediment

Taking the second stage of breakwater project at Zhangjiabu port as background, a 2-D numerical model based on irregular triangular mesh is used to simulate the tidal current field, the transport of suspended sediment, the change of scouring and silting, as well as the siltation of channel in the project area and nearby. The research results show that: (1) the project area has the feature of semi-diurnal current and the tidal current shows a reciprocating characteristic, and it flows to northwest during flood tide and northeast during ebb tide, and the construction of the breakwater has no significant impact on the surrounding current field, (2) after completion of the breakwater, the velocity on the north side of breakwater decreases, and the sediment silts up, but on the south side of breakwater, it appears a scouring pit because of the role of spoiler, (3) the annual mean siltation thickness is about 0.06m/a in the harbor basin and 0.25m/a in the channel, and the max thickness is 0.53 m/a, the volume of sediment siltation in the whole area is 112000 m³/a.