高海拔地区台阶式溢洪道的时均压强特性研究

Mean pressure on stepped overflow dam at high altitude area

通过模型试验,研究了青藏高原地区某水库台阶式溢洪道台阶处的时均压强特性。研究表明：在台阶的水平面,从台阶的内缘向外缘压强逐渐减小,最小值出现在距离台阶内缘大约0.35~0.5倍的步长,最大值出现在距离台阶内缘大约0.7~0.8倍的步长;在台阶的铅直面,受到水平台阶的影响,距离台阶内缘大约0.2~0.4倍的步高时,开始出现负压,负压的最大值出现在大约0.5~0.6倍的步高范围内。台阶水平断面处的时均压强沿程分布,呈现出明显的波浪式变化,负压所在范围与低海拔地区差别不大,但负压最大值所占台阶高度减小。

The mean pressure of a stepped overflow dam on Qinghai -Tibet plateau was measured u-sing a model .Experimental studies have shown that the mean pressure at the step surface falls down .The minimum point is in the distance of 0 .35~0 .5 time pace from the nook while the maxi-mum point is in the distance of 0 .7~0 .8 time pace .The mean pressure on the vertical section is in-fluenced by level steps.The negative mean pressure appears in the distance of 0.2~0.4 time pace. The maximum negative mean pressure point appears in the range of 0.5~0.6 time pace.The pres-sure distribution of horizontal section along spillway presents a wavy change .The negative pressure range is similar to that in low -lying area , but the largest negative pressure range decreases .