强输沙对陡坡河道水位激增的影响试验研究

Experimental Study of Water Level in Steep Channel Flow Under High Sediment Concentration

为加强对泥沙附加致灾作用的认识,采用单因素叠加的试验方法,通过陡坡水槽试验对强输沙条件下的水位变化规律进行了初步探索。试验结果表明:陡坡河道上的高强度泥沙输移,一方面增加了水流通量,另一方面增加了水流阻力,两者均可导致水位的显著增加。试验水槽内水深随着泥沙的加入而显著增加,并随着输沙过程的结束而回落。总体上,中等粒径的泥沙引起的水位增幅最高;随着水深的增加,水深增长率(增幅)存在先增大后减小的规律。此外研究还发现,河道比降越陡,水位增幅越大,最大水深增长率与河道比降间呈指数关系。

In order to better understand the additional disaster of sediments,the regulation of water level variation under high concentration of sediments in steep channel flow was studied through single factor experiment method. The results revealed that the high concentration sediments not only increased the water volume,but also contributed to water resistance. Both of them could make water level of river rise significantly. Generally the medium grain size of sediments caused the highest growth rate of water depth in all conditions. The growth rate first increased and then decreased with the increase of water depth. Refering to results of previous research,the results also revealed that the deeper the slope was,the higher the growth rate became. There was a exponential relationship between maximum growth rate and slope.