支流汇入干流后稳流消能设计研究

The steady flow energy dissipation design after tributaries merging into main stream

水流交汇是天然河道普遍存在的自然现象,在河道设计中若处理不好,会给工程带来潜在危险。以河北省张家口市崇礼区太子城冰雪小镇防洪工程为例,研究山区河道暗涵交汇水流在交汇口处的水面形态特征,通过水工模型试验及数值计算,分析研究支流汇入干流后稳流消能效果、流态及水面衔接,验证优化工程设计,避免流水不畅影响排水,防止消能过大引起水深加大,造成下游暗涵闷孔、溢流。结果表明:单独增加支流或干流流量的情况下,消能池稳流消能效率增大;同频率增加支流及干流流量时,消能池稳流消能效率逐渐减小,符合当地防洪排水条件,水工模型试验结果与数值计算结果基本一致。通过数值计算进行水工模型试验,是解决复杂汇流条件的水工建筑设计的优选方法,可供类似工程借鉴。

The confluence of water flow is a common confluence phenomenon in natural river course.If the design of river course is not handled properly,it will bring potential danger to the project.With the flood control project of Taizicheng Ice and Snow Town in Chongli District,Zhangjiakou City,Hebei Province as the example,this paper studies the water surface morphology characteristics at the intersection of water flow in dark culverts in mountainous areas.Through hydraulic model test and numerical calculation,this paper analyzes and studies the steady flow energy dissipation effect of tributaries merging into the main stream,the flow pattern and water surface connection,and verifies the optimization of engineering design to avoid the influence of poor water flow on drainage.Avoid excessive energy dissipation to increase the depth of water,and then cause the downstream dark culvert stuffy hole,overflow.The results show that the steady flow and energy dissipation efficiency of the energy dissipation pool increases when the flow of tributaries or main streams is increased separately.When the flow of tributaries and main streams is increased at the same frequency,the steady flow and energy dissipation efficiency of the energy dissipation pool gradually decreases,which also conforms to the local flood control and drainage conditions.The results of hydraulic model test are in good agreement with those of numerical calculation.Through this study,it is considered that numerical calculation and then hydraulic model test verification is a better way to solve the complex confluence conditions of hydraulic building design,and can also be used as a reference for similar projects.