MU Xiangpeng, CHEN Wenxue, LIU Shuang, ZHONG Huirong, ZHANG Xuehuan

Abstract: The key to water transfer under the ice cover in South-to-North Water Diversion Middle Route Project during winter is to control the hydraulic conditions, under which the ice boom can intercept the ice floes effectively and ice floes can accumulate and form ice cover in front of the ice boom. In this paper, based on the prototype observation data of South-to-North Water Diversion Middle Route Project, the critical hydraulic conditions of floating ice diving are analyzed. The analysis result shows that the traditional second critical Fr (0.08~0.09) is only applicable to identifying the ice floe motion in front of the leading edge of the ice cover, but has eimieaeions identifying the ice floe motion in front of the ice boom. Then according to the research results of the ice drowning at the submerged orifice, the formula of the critical Froude number of the ice diving is recommended in front of the ice boom,and the rationality of the formula is verified. The study shows that the greater the submerged depth of the ice boom,the better the ice intercepts,and the greater the critical Fr value for ice diving in front of the ice boom. At last the minimum submerged depths of the ice booms of South-to-North Water Diversion Middle Route Project are deter-mined. The results provide a theoretical basis for making water transfer plan and ice booms modification of South-to-North Water Diversion Middle Route Project.

Keywords: Ice hydraulics; long-distance water transfer canal; water transfer under ice cover; hydraulic control; ice boom

(Journal of China Institute of Water Resources and Hydropower Research, Vol. 16, No. 2, 2018)