射流冲击下护坦板块失稳机理的随机分析

The Random Analysis of Apron Slab under the Percussion Action of Jet Flow

高水头射流是水利工程中常见的水力现象。挑跌流消能是我国泄水工程中较普遍采用的消能方式。鉴于高速水流对护坦板块的破坏作用及对建筑物的影响一直没有弄清楚,本文从水力学随机过程理论的观点出发,结合二滩水电站双曲拱坝消能防冲作了模拟试验研究。将护坦板块在水流作用下的特性视为二阶矩随机过程x(t),寻求x(t)与它的导函数x(t)、x(t)的相关矩:从而求出各阶谱矩 分析了护坦板的随机属性,探讨了射流对下游河床的动水作用与护坦板失稳过程的水力学机理;分析了使护坦板块失稳的上举力的成因;指出了增加护坦板稳定性的条件。

In this paper, from the viewpoint of random hydrolics, the experimental research on the problem of percussion action of the jet flow related to the apron slab in Ertan Hydroelectric Project is conducted.Stochastic theory and random time series are employed to analyse the sample function x(t), its x(t) and x(t) and their corelations:〈x,x〉 〈x,x〉 〈x,x〉〈x,x〉 〈x,x〉 〈x,x〉 The moments of the spectra are obtained:M0 0 -M2 0 M2 0 - M2. 0 M4The working process of the apron during the variation of flow discharge has been observed and the mechanism of failure of apron slab is discussed.The lift force due to the action of jet flow is analysed and the conditions of improving the safety factors of apron slab are presented.