高含沙泄洪水流的荷载特性试验研究  

Experimental study of load characteristics on hyperconcentrated discharge flow

作　　者：练继建[1] 杜昀怡 刘昉[1] 胡剑超[1] 

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072

出　　处：《水利学报》2017年第11期1261-1268,共8页Journal of Hydraulic Engineering

基　　金：国家重点研发计划(2016YFC0401904);国家自然科学基金项目(51579172;51409187;51509180);天津市应用基础与前沿技术研究计划(青年项目)(15JCQNJC07100);国家自然基金委创新团队(51621092)

摘　　要：高含沙水流特性已有较多研究,但主要针对河道中的高含沙渐变水流开展的,而对高含沙河流高坝枢纽泄洪水流荷载特性的研究较少,本文开展了孔板消能工高含沙水流的时均压力和脉动压力特性研究。试验共研究了含沙量从0至300 kg/m^3,流速从1.78 m/s至3.73 m/s,共28组不同工况。结果表明:高含沙泄洪水流的时均和脉动压力的沿程分布规律与清水相同,但幅值变化规律存在差异,相同流速条件下时均压力幅值随含沙量的增加而增加,而脉动压力幅值受含沙量和流速条件的双重影响,随含沙量的增加呈现出先增加后减小的趋势;脉动压力概率密度分布符合正态;频率分布范围受水流条件影响随流速的增加而增加,其中低频分量随含沙量的增加而增加。根据试验结果,提出了高含沙泄洪水流荷载计算的修正方法,该方法对于高含沙枢纽的工程设计有重要参考价值。The characteristics of hyperconcentrated flow have been deeply studied by former scholars, and most of them are about gradually varied flow in the riverway, but are barely about the load characteristics of high dam discharge flow on hyperconcentrated river. In this paper, the time-average pressure and fluctu- ating pressure of orifice energy dissipater were studied. The experiment contained 28 different conditions, with sediment concentration ranging frmn 0 to 300kg/m3, and velocity ranging from 1.78m/s to 3.73m/s. The results show that： the time-average pressure and fluctuating pressure of high darn hyperconcentrated dis- charge flow has the same distributing rule as the pure water, but differs in the value, the value of time-average pressure increases as the sediment concentration increases under the same velocity condition, while the fluctuating pressure is affected by both the sediment concentration and the velocity condition, which declines after the first increase; the probability density of fluctuating pressure follows the normal dis- tribution; the frequency distribution range of fluctuating pressure increases as the velocity increases, and the low frequency component increases as the sediment concentration increases. Based on the results, this paper proposed a load calculation correction method which has an important value of project design on hy- perconcentrated rivers.

关 键 词：高含沙泄洪水流 孔板消能工 时均压力 脉动压力 荷载计算修正方法 

分 类 号：TV149.2[水利工程—水力学及河流动力学]