宁夏扬黄灌区逆坡直线边墙渐扩矩形断面沉沙池参数优选

Parameter Optimization for the Reverse Slope Straight Line Wall Progressively-expanding Rectangular Section Sedimentation Basin of the Yellow River Pumping Irrigation Area in Ningxia

工农业生产实践中多采用顺坡平流型沉沙池沉降悬移泥沙,但由于结构形式的限制,顺坡沉沙池很难提高其沉淀效率。针对宁夏扬黄灌区泥沙的特点,采用准静水沉降法和一维超饱和输沙法,对比分析了顺坡沉沙池和逆坡直线边墙渐扩矩形断面沉沙池的泥沙沉降效率。结果表明,逆坡直线边墙渐扩矩形断面沉沙池是一种高效沉沙池。对1 m 3/s流量下沉沙池的设计参数进行优选,提出了适合于宁夏扬黄灌区的合理参数取值:坡度-0.005 0、扩散角9°、池长400 m、出口宽度134.71 m,此时泥沙沉降率为86.87%。

In the practice of industrial and agricultural production,the sedimentation of suspended sediment is mostly carried out by the downslope sedimentation basin,but it is difficult to improve the sedimentation efficiency due to the limitations of its structure.In this paper,according to the sediment characteristics of the Yellow River pumping irrigation area in Ningxia,the sediment settlement efficiency of downslope sedimentation basin and the reverse slope straight line wall progressively-expanding rectangular section sedimentation basin are analyzed by means of the quasi hydrostatic settlement method and the one dimension extra saturation sediment discharge method respectively.The results show that the reverse slope progressively-expanding rectangular section sedimentation basin is an efficient sedimentation basin.The parameters of the sedimentation basin under 1 m 3/s flow rate are optimized,and the reasonable parameters suitable for the Yellow River pumping irrigation area in Ningxia are proposed accordingly.With the gradient of-0.005 0,diffusion angle of 9°,pool length of 400 m and outlet width of 134.71 m,the sediment deposition rate reaches 86.87%.