南水北调中线干渠冰期输水能力研究

Study on Water Diversion Capacity in the Middle Route of the South-to-North Water Transfer Project in Ice Period

冰盖的形成使得渠道的湿周增加,水力半径减小,输水阻力加大,致使渠道过流能力减小,影响渠道的冬季输水。渠道冰期的输水能力无论对工程设计,还是运行管理都是十分重要的。文章分析了结冰期冰盖的安全推进模式和稳定封冻期渠道水位壅高的影响,提出了确定渠道在结冰期和稳定封冻期的输水能力的控制指标,在此基础上,对南水北调中线黄河以北渠段结冰期以及完全封冻后的输水能力进行了研究,确定了南水北调中线黄河以北干渠的冬季输水能力,研究成果对于南水北调中线干渠的冬季管理和运行具有一定的参考价值。

The ice cover in canal can increase wetted perimeter,reduce hydraulic radius and increase hydraulic resistance,which can diminish the water diversion capacity of canal.The water diversion capacity of canal in winter is very important to design and management.In this paper,the factors to determine the water diversion capacity of canal are put forward,based on rising of water level and progress of ice cover.Through the calculation of steady nonuniform flow with composite roughness coefficient,water diversion capacity during freeze-up period and ice-covered period is researched and water diversion capacity is put forward for part of the Middle Route of South-to-North Water Transfer Project in north of Yellow River in winter.The results are important for water diversion of the Middle Route of South-to-North Water Transfer Project in ice regime.