岱山—洋山跨海通道水沙环境影响数值模拟研究

Numerical simulation study on the hydro-sediment environmental impact of the Daishan-Yangshan Cross-Sea Channel

杭州湾是世界闻名的强潮河口,具有不规则的岸线边界、独特的地形地貌特征和复杂的水动力泥沙环境。岱山—洋山跨海通道位于杭州湾湾口水域,将岱山与洋山近35km连通,实现了上海—洋山—岱山—舟山—宁波跨海通道的全线贯通,其建设具有非常重要的意义。基于考虑波浪作用的潮流泥沙数值模型,讨论了岱山—洋山跨海通道几种工况对杭州湾大范围海域水沙环境的影响。研究结果表明:跨海通道实施后潮位变化在大桥轴线附近较为敏感,远离则基本没有影响,高低潮位变化幅度大多在2 cm以内。杭州湾涨落潮量减小小于0.6%。水流流态和水下地形仅在大桥附近水域存在明显变化。从对杭州湾水沙环境影响角度考虑,岱山—洋山跨海通道几种工况均可行,建议关注桥墩和人工岛附近的局部冲刷问题。

Hangzhou Bay,renowned for its strong tidal currents,features an irregular shoreline,unique topography,and a complex hydrodynamic sediment environment.The Daishan-Yangshan Cross-Sea Channel,located at the mouth of Hangzhou Bay,spans approximately 35 kilometers connecting Daishan and Yangshan.This completion links the entire Shanghai-Yangshan-Daishan-Zhoushan-Ningbo cross-sea channel,marking its significant importance.Utilizing a numerical model considering wave effects on tidal currents and sediment,this study explores the impact of various conditions of the Daishan-Yangshan Cross-Sea Channel on the watersediment environment in the extensive marine area of Hangzhou Bay.The findings indicate that the tidal level changes are more sensitive near the bridge axis,with minimal impact farther away,and the amplitude of tidal level changes mostly stays within 2 cm.The percentage reduction in tidal range in Hangzhou Bay is less than 0.6%.Significant alterations in water flow patterns and underwater topography are observed only in the vicinity of the bridge.Considering the environmental impact on the water-sediment environment in Hangzhou Bay,the different conditions of the Daishan-Yangshan Cross-Sea Channel are deemed feasible,with a recommendation to address localized erosion issues near bridge piers and artificial islands.