无坝取水分流防沙试验研究

都江堰水利工程是人类历史上无坝取水工程的典范。研究分析了都江堰工程的布置特点以及引水防沙原理,与现代分流拦沙技术相结合,应用于我国西部山区某河流的取水枢纽布置。通过模型试验,在河道主流中心位置布置人工岛,将河道分为内江和外江,模拟枢纽的取水防沙效果。结果表明:在内江入口处设置拦沙坎减小了进口附近河段的流速,有效阻碍了泥沙进入,不影响工程取水效果;受拦沙坎影响,内江流速小于天然河道,但由于人工衬砌的内江底部糙率小于天然河道,泥沙随水流一起向下游运动,在弯道环流下大部分泥沙沿人工岛一侧运动并从飞沙堰排入外江,少量进入取水口泥沙沉积在沉沙池。

Experimental study on sediment control of dam-free water diversion

The Dujiang weir irrigation project is a model of water intaking in human history. Through studying and analyzing the layout of the Dujiang weir irrigation project and its principles of diversion and sediment control, and combining with modern diversion and sediment retaining technologies, some references are provided for the layout of a water intake project on a mountainous river in western China. The physical modeling results show that setting a sediment sill at the entrance of water diversion branch can reduce the flow velocity and effectively restrain the sediment entering the water diversion branch, while it has no adverse effects on water taking. Due to the effect of the sediment sill, the flow velocity in water diversion branch is smaller than that of the natural river channel, but the lined bottom resistance in the water diversion channel is smaller than that of the natural river channel, making the entered sediment flow downward and under the effect of bend channel flow, most of the sediment in the diversion channel can flow out to the natural river from the flood diversion weir, while the remained sediment settles in the sediment pool at the water intake mouth.