挡潮闸外迁对闸下水动力特征影响的概化模型研究

Generalized model study on influences of sluice migration on hydrodynamic characteristics downstream

以苏北沿海的王港河口为原型,建立潮汐河口三维水动力概化数学模型,分别对挡潮闸迁移前、后的闸下水动力过程进行模拟。通过对比闸下潮位、流速及流向的特征变化,分析挡潮闸外迁的相关影响。结果表明:挡潮闸外迁后,闸下潮波变形现象减弱,涨、落潮历时趋于相近、不对称性减弱,有利于改善涨落潮流输沙不等现象;闸下水动力环境增强,平均流速增大,垂向各层流速的分布更加均匀,且表、底层流速比增大,有利于加强闸下冲刷、减轻淤积;闸门外迁对河口外的流速分布影响较小。上述结果可为类似的强潮流河口挡潮闸外迁论证以及外迁后的闸下淤积研究提供参考。

Based on the terrain of Wanggang estuary along the northern coast of Jiangsu province,a 3-D hydrodynamic generalized numerical model was developed to simulate the hydrodynamic process downstream the tidal sluice before and after the migration.By comparing different features such as tidal level,flow velocity and flow direction under the gate,the influences related were analyzed.The result shows that:After the migration of tidal sluice,tidal wave deformation gets weakened,the rising and falling tides tend to be similar and tidal asymmetry gets weakened,contributing to improving the uneven sediment transport of tide;Hydrodynamic environment downstream gets strengthened,current speed gets increased,the vertical distribution of the flow rate is more even and the ratio of surface and bottom flow rate gets increased,which help to reduce the gated siltation;Sluice migration has little effect on velocity distribution near the estuary.The results above can be used as a reference for the feasibility demonstration of sluice migration in strong tidal estuary and the study of gated siltation after migration.