台阶式溢流坝的时均压强特性  

The characteristics of mean pressure on stepped overflow dam

作　　者：田嘉宁[1] 魏炳乾[1] 李布雳 冯瑞林[3] 李建中[1] 

机构地区：[1]西安理工大学,西安710048 [2]广西电力工业勘测设计研究院,广西桂林530023 [3]中水顾问集团昆明勘测设计研究院,昆明650011

出　　处：《水力发电学报》2007年第6期67-72,共6页Journal of Hydroelectric Engineering

基　　金：陕西省自然科学基金(E218);西安理工大学博士科研基金(210602)

摘　　要：当yc/h<3时,3种坡度(40°、50°和60°)的台阶式溢流坝试验结果证明,在初始台阶上,作用在水平面上的时均压强均为正值,其最大压强随流量增大,由台阶中部逐渐移向台阶外边缘;跌落水流时台阶竖直面上部范围出现的负压,在进入过渡水流以后全部变为正值。其他各台阶水平面上,除挑射水流越过的数个台阶外,在各级流量下时均压强为正值,其最大值均在台阶外边缘;台阶竖直面上部的时均压强为负,下部的时均压强为正,随流量增加负压绝对值增大,范围缩小。其中跌落水流时负压占台阶高度的75%,进入过渡水流后负压约占台阶高度的60%。Experimental results on the stepped overflow dam （respectively with a slope of 40°, 50° and 60° when yc / h 〈 3） show that on the first step, the mean pressure on the horizontal plane is positive, and the maximum value moves from the middle to the edge with the increase of discharge; the negative mean pressure appears on the upper part of the vertical plane in nappe flow while mean pressure becomes positive in transition flow. Except the few steps jumped over by jump flow, the mean pressure on the horizontal plane of all the other steps is positive and the maximum value is on the edge of steps. On the vertical plane of a step, the mean pressure appears negative on the upper part while it becomes positive on the lower part. With the increase of discharge, the absolute value of negative mean pressure increases while its regime dwindles. The negative pressure reaches 75 % step height in nappe flow and 60% step height in transition flow.

关 键 词：水工结构 时均压强 模型试验 台阶式溢流坝 

分 类 号：TV651.1[水利工程—水利水电工程]