沁北蓄滞洪区冲刷对引丹入城工程埋管的影响

Influence of Erosion in Qinbei Flood Detention Basin on Pipe-burying in Bring-Dan River-to-Qinyang Project

沁河与支流丹河的夹角区域为沁北自然溢滞洪区,沁阳市引丹入城工程输水管线以埋管方式穿越沁河北岸天然蓄滞洪区。沁河上游流量过大时,河道内洪水从堤防缺口自然溢入蓄滞洪区,会对沁北滞洪区范围内的输水管线造成一定的冲刷影响。通过MIKE21水动力学模型对50年一遇洪水过程条件下沁河、丹河和沁北滞洪区范围内的洪水演进过程进行了模拟,结果表明,丹河口最先发生漫溢,其次是阳华缺口,最后是上游龙泉缺口,阳华缺口漫溢水流与另外2个缺口漫溢水流相连接,洪峰过后,洪水沿原缺口退回河道;输水管线沿线地面以下计算最大冲刷深度为2.53m。

The angle region between Qin River and its branch Dan River is Qinbei natural flood detention basin. The water supply pipe line of Bring-Dan River-to-Qinyang Project will be buried passing the natural flood detention basin in the north bank of Qin River. If the upstream discharge of Qin River is excessive, the flood will overflow from the levee breach into the flood detention basin, which will have erosion influence on the water supply pipeline in Qinbei flood detention basin. The flood evolution process in Qin River, Dan River and Qinbei flood detention basin under the 50-year flood is simulated by means of MIKE21 hydrodynamic model. Results show that Dan River mouth overflows first, then Yanghua breach, and at last the upstream Longquan breach. Flood of three breaches connect together. After the flood peak, the flood returns to the river course through the breach. The calculated maximum erosion depth of buried pipes is 2.53 m.