外秦淮河武定门闸上游减淤物理模型试验

针对南京市外秦淮河武定门闸上游近年来发生泥沙淤积严重的问题,建立了武定门闸河段物理模型,设定两种方案进行悬沙冲淤试验,分析偏转角为15°的导流墙工程对闸上游的减淤作用。结果表明:方案1(将闸门至上游60 m开挖至设计断面),设置导流墙后,经过2年8个月的水沙过程,整治段淤积量减少30.4%;方案2(将闸门至上游240 m开挖至设计断面),设置导流墙后,经过1个典型水文年,整治段淤积量减少50.8%,经过2个典型水文年,淤积量减少44.0%,减淤幅度下降,河床趋于形成新的冲淤平衡,断面地形也趋向于均匀分布;设置偏转角为15°的导流墙对武定门闸上游河道有显著的减淤作用,有助于提高河道的过流能力。

Physical model experiment of silt reduction in upper reaches of Wudingmen sluice in outer Qinhuai River

Due to serious sediment deposition in the upper reaches of Wudingmen sluice in the outer Qinhuai River in Nanjing, a physical model was established and two schemes were designed to study the silt reduction effect of a diversion wall with a 15°deflection angle in the upstream of the sluice. In scheme 1, a scope of 60 m upstream of the sluice was excavated to the design section. After two years and eight months of flow and sediment process, the sediment volume in the regulated section was reduced by 30. 4% after the diversion wall configuration. In scheme 2, a scope of 240 m upstream of the sluice was excavated to the design section also with a diversion wall. The sediment volume of the regulated section was reduced by 50. 8% and 44. 0% after one and two typical hydrological years respectively. The range of sediment reduction decreased, the riverbed tended to form a new balance between erosion and deposition, and the topography of the section tended to show a uniform distribution. The results show that the diversion wall with a 15°deflection angle can significantly reduce the siltation in the upstream of the Wudingmen sluice and can improve the flow capacity of the channel.