杭州湾跨海大桥对钱塘江河口水流的影响

The impact on the flow of Qiantang Estuary by the Hangzhou Bay Major Bridge

通过河工模型试验,研究建设在潮汐河口的特大型桥梁——杭州湾跨海大桥对水环境产生的影响。杭州湾跨海大桥河工模型上边界选在老盐仓,下边界定在金山,平面比尺为1000,铅直比尺为100,模拟总水域面积约2200km2;模型运用2000年9月杭州湾实测水下地形及大范围同步水文测验资料进行了验证,其精度较高。在此基础上,结合实测资料分析,运用定床模型试验对杭州湾跨海大桥建成后附近水域流态的变化及对钱塘江涌潮、上游行洪等的影响进行了分析和预测。建桥前后潮位、流速流向、潮流量以及涌潮高度等试验数据的变化表明,杭州湾跨海大桥建成后对钱塘江河口水流的影响主要在桥位近区,对涌潮、上游行洪基本没有影响。

Studying the impact on the water environment of the Qiantang estuary by the Hangzhou Bay Major Bridge which is a huge bridge will be built across the estuary using the physical river model. Laoyancang and Jinshan are selected as the upstream and downstream boundaries of the physical river model for the Hangzhou Bay Major Bridge. Horizontal scale \%λ\-l\%=1 000 is chosen and verticala scale \%λ\-h\%=100. Total simulation area is about 2 200 km\+2. The physical model moulded to the underwater charts of September 2000 is verified with hydrometic data at the same time and the verification has reached a higher accuracy. Based on verification of the field measurement, it is forecasted that the impact on the flow, the tidal bore and the flood of the Qiantang River, etc through the physical model combining the situ data. After the bridge is built the change of tidal water level, velocity, flow direction,tidal amount and bore height indicates that the influence of the Hangzhou Bay Major Bridge on the flow of the Qiantang Estuary is mostly nearby the bridge, and to the tidal bore and the flood is slight in essence.