摘要
冰盖糙率是确定渠道冰期输水水位和流量关系的基础参数,一直是明渠冰工程研究的重点之一。鉴于当前大型混凝土渠道冰盖糙率研究成果相当匮乏,以南水北调中线总干渠石家庄以北唯一无输水建筑物的唐河节制闸—放水河节制闸渠段为研究区域,依据全线通水以来唯一生成全渠段封冻冰盖的2016年1—2月逐日水位和流量实测数据,采用伯努利能量方程和谢才-曼宁公式推求渠道糙率,定性定量分析封冻前后渠道糙率变化特征。结果表明:①研究渠段畅流期渠道糙率n b为0.0167,封冻期冰盖综合糙率n c为0.0146,冰盖下表面糙率n i为0.0118。②由于水力磨蚀作用,封冻期冰盖糙率随时间呈波动减小的趋势。③渠道一旦生成封冻冰盖,输水能力大幅降低,仅占渠道设计流量的66.7%。该研究给出了大型混凝土渠道封冻冰盖糙率和输水能力降低的确切数值,以期为冰期输水调度和类似工程设计提供科学依据。
As a research focus for ice-involved open channel projects,the roughness of ice cover is a fundamental parameter for determining the relationship between water level and discharge in open channels during freezing period.Given the current lack of data on ice sheet roughness in large-scale concrete channels,we investigated the channel section between Tanghe sluice gate and Fangshui sluice gate of the Middle Route of the South-to-North Water Diversion Project in the north of Shijiazhuang as a case study.Utilizing daily measured data of water level and flow rate from January to February 2016,we employed the Bernoulli energy equation and the Xie Cai-Manning formula to estimate channel roughness and analyze the changes in roughness before and after freezing,both qualitatively and quantitatively.The results are as follows:1)The roughness coefficient n b of the studied channel during free-flow period is 0.0167.The average comprehensive roughness n c of the ice sheet during freezing period is 0.0146,and the average surface roughness n i beneath the ice sheet is 0.0118.2)Due to hydraulic abrasion,the roughness of ice sheet decreases over time during freezing.3)Once ice sheet is formed in the channel,the water delivery capacity significantly diminishes,achieving only 66.7%of the designed flow rate.These findings provide a scientific basis for optimizing water transportation scheduling and designing similar engineering projects during freezing period.
作者
段文刚
邢梦媛
黄明海
杨金波
沙继婷
DUAN Wen-gang;XING Meng-yuan;HUANG Ming-hai;YANG Jin-bo;SHA Ji-ting(Hydraulics Department,Changjiang River Scientific Research Institute,Wuhan 430010,China)
出处
《长江科学院院报》
CSCD
北大核心
2024年第10期78-85,118,共9页
Journal of Changjiang River Scientific Research Institute
基金
国家重点研发计划项目(2017YFC0405000)。
关键词
南水北调中线工程
冰盖糙率
渠道糙率
输水能力
水头损失
South-to-North Water Diversion Middle Route Project
ice cover roughness
channel roughness
water transfer capacity
head loss
