泾河东庄水利枢纽工程双泥沙侵蚀基准面排沙研究

Study on Double Sediment Erosion Base-Level of Dongzhuang Hydraulic Project in Jinghe River

针对泾河东庄水利枢纽拦沙库容淤损快、淤损后无法重复利用等问题,提出在坝前创造"正常+非常"双泥沙侵蚀基准面实现拦沙库容再生利用的设计理念和排沙技术。采用理论分析、数学模型计算、实体模型试验等方法,对东庄水库设置排沙泄洪深孔和非常排沙底孔、仅设置排沙泄洪深孔两种工程布置进行对比分析,结果表明,设置排沙泄洪深孔和非常排沙底孔形成的"正常+非常"双侵蚀基准面可延长水库拦沙库容使用年限3 a,减少库区淤积量3.92亿m^(3),一次运用可恢复拦沙库容近1.0亿m^(3),实现"死"库容"不死",长期发挥水库拦沙减淤效益。研究成果促成了工程落地,开启了在100 kg/m^(3)级以上含沙量河流上建设重大水工程的先河。

Aiming at the issues such as rapid silting loss of sediment storage capacity of Dongzhuang Hydraulic Project and inability to be reused after silting,the design concept and sediment sluicing technology of double sediment erosion base level in front of the dam to realize the recycling of sediment storage capacity were put forward.By theoretical analysis,1 D water-sediment mathematical model of reservoir and river channel and physical model experiment,two kinds of engineering layout were compared.One was to set up a low-level outlet for flood discharging and sediment sluicing and an extraordinary sediment bottom sluice simultaneously and another was to set only a low-level outlet for sand discharge and flood sluicing.The results show that the double erosion base-level design can prolong the service life of the sediment control capacity of the reservoir,reduce the accumulated silting in the reservoir area and reduce the silting in the lower reaches of Weihe River.At the same time,an engineering application method of forming double sediment erosion base level was proposed.The dead storage capacity was reused,the first major water projects on rivers with sediment concentration above 100 kg/m^(3) was opened.