泥石流入汇主河情况下交汇口附近变化规律的试验研究

Experimental study on evolution of debris at the vicinity of confluence

本文在试验的基础上,分析了泥石流入汇主河后,汇口附近各水力参数的变化规律。探讨了泥石流入汇后下游水位相对壅高与流量比以及交汇角的关系,得出相对壅水高度随流量比及交汇角的增大而增大的结论。分析了主河在入汇口附近的淤积变化规律。在30°、60°和120°交汇情况下,淤积量随支流流量及流量比的增大而增大;淤积率则随总流量增大而减小,在主支流量相当时出现最大值。90°交汇时,淤积量随支流流量及流量比的增大而减小;淤积率随总流量增大而增大,在主支流量相当时出现最小值。平均及最大淤积深度在主支流量相当时出现最大值。顺河向交汇时,淤积深度最大值随交汇角增大而增大,120°交汇时淤积深度与30°交汇时相当。

The hydraulic characteristic of debris at the vicinity of confluence is studied experimentally. It is found that the back-up water level rate upstream of the confluence increases with the increase of discharge ratio(tributary discharge to total discharge) and influence angle. The deposit volume in the main channel increases with the increase of discharge ratio, but the deposit rate will reduce as the total discharge increases, a maximum will occur when the discharge of tributary is equal to that of main channel. If the confluence angle is 90°, the deposit volume decreases with the increase of tributary discharge and discharge ratio, but the deposit rate will increase as the total discharge increase, and a minimum will occur when discharge of tributary is equal to that of main channel.