不同引河长度下河口闸下淤积形态数值研究

study on profile of siltation downstream tidal barrage according to different irrigation channel lengths

闸下淤积是河口建闸的关键问题,直接关系到工程的成败。基于甬江及口外海域金塘水道实测水文泥沙资料,建立平面二维水沙数学模型,分析计算不同引河长度下的闸下淤积特点以及对北仑港区、镇海港区水沙运动和地形变化的影响。计算结果表明:在上游径流及外海来沙相同的条件下,闸址离河口越近,闸下河道因建闸引起的淤积量越小,但闸下淤积强度越高;建闸对北仑港区无显著影响,对镇海港区影响较大,当闸址位于镇海港区上游时,闸址距港区越近,淤积影响越显著。

Siltation at the downstream of tidal barrage is the key problem of the construction in estuaries, which is directly related to the success of the project. According to the hydrologic and sediment observation data of Yongjiang river and sea area nearby, a 2D water and sediment mathematical model was established in this paper. The amount of siltation was calculated based on different irrigation channel lengths, and the influence of the barrage on Beilun Port and Zhenhai Port was also analyzed. The results show that when the runoff and incoming sediment from sea remain the same, the closer the barrage away from the estuary, the less siltation increases, while the higher siltation intensity it is. The project of barrage has no influence on sediment deposition of Beilun Port, but remarkable influence on Zhenhai Port. When the barrage locates upstream against the port area, the closer the barrage away from the port, the greater the strength of siltation.