嵊泗壁下岛渔港码头冲淤预测研究

Prediction of scouring and silting of Bixia island wharf project in Shengsi

2017年在浙江嵊泗壁下岛海域进行水文调查,数据经整理后,进行了潮流和冲淤数值模拟研究,结果显示:(1)拟建码头实施后,码头平台及栈桥区域流速普遍减小,流速减小不超过0.05 m/s,减幅在10%~60%之间;码头前沿30 m以外水域流速略有增大,增幅小于0.01 m/s,增幅不超过8%。工程实施后,码头前沿30 m范围内和后方栈桥水域由于流速减小,挟沙能力减弱,悬沙有落淤趋势。(2)首年淤积量一般在5~15 cm/a;码头前沿30 m以外水域,流速虽然较工程前有所增大,但仍远小于泥沙的起动流速,不足以使海底泥沙起悬而形成冲刷,因此该水域地形基本不会变化。

Based on the hydrological survey in Bixia island of Shengsi,Zhejiang Province in 2017,the numerical simulation of tidal current and erosion and deposition was carried out.The results showed that:(1)After the implementation of the proposed wharf,the flow velocity in the wharf platform and trestle area generally decreased,with a decrease of no more than 0.05 m/s,ranging from 10%to 60%;The flow velocity in the water area 30 m away from the wharf front increased slightly,the increase was less than 0.01 m/s,and the increase was not more than 8%.After the implementation of the project,due to the decrease of the flow velocity,the sediment carrying capacity of the area within 30 m of the wharf front and the water area behind the trestle was weakened,and the suspended sediment tended to deposit;(2)In the first year,the sedimentation amount was generally 5~15 cm/a.Although the velocity of the water area 30 m away from the wharf front was higher than that before the project,it was still far less than the starting velocity of the sediment,which was not enough to make the seabed sediment suspended and form scour.Therefore,the topography of the water area will not change basically.