韩江三河坝—高陂枢纽段河床演变及航道治理效果研究

以韩江中游三河坝—高陂枢纽河段为例,在分析2002～2017年实测枯水河槽冲淤、航道条件及水沙条件基础上,利用平面二维水沙数学模型计算手段,计算确定了通航设计水位、航道整治工程的初步效果。研究结果表明,2002～2017年期间,三河坝—高陂枢纽河段枯水河槽由淤积逐渐转为冲刷,深泓平均下切1.92m,2015～2017年与2008～2015年相比,枯水河槽冲刷强度有所放缓;确定了三河坝—高陂枢纽段最低、最高通航水位;核查最低通航设计水位下2.5、3.0m的航道水深,三河坝—高陂枢纽河段无碍航浅点;在航道尺度提升中,现状地形满足航道尺度提升的水深要求,航宽仍需进一步增加,主要通过拆除部分已建丁坝来实现增加航宽的目的,丁坝拆除工程实施后航槽内的最大、最小流速略有减小,航道水深仍满足规划目标要求。

Study on River Bed Evolution and Channel Regulation Effect of Sanhe Dam-Gaobei Junction of Hanjiang River

Taking the Sanhe Dam-Gaobei Junction in the middle reaches of the Hanjiang River as the research object,the measured topographic data from 2002 to 2017 were collected and analyzed.Based on the analysis of the scouring and silting,channel conditions and water-sediment conditions of the watercourse at its low-flow channel,the preliminary effects of navigation’s design level and channel regulation were analyzed by two-dimensional water-sediment mathematical model.The results show that during the period of 2002-2017,the watercourse at the low-flow channel of Sanhe Dam-Gaobei Junction gradually changed from silting to scouring with the average sapped thalweg of 1.92 m.Compared with 2008-2015,the scouring intensity of the low-flow channel slowed down in 2015-2017.The lowest and highest navigation water levels of Sanhe Dam-Gaobei Junction were determined.The channel depths of 2.5 mand 3.0 mbelow the lowest navigation design level were checked,and it was found that the reach of Sanhe Dam-Gaobei Junction has no channel obstructed and shallow points.In the course of channel scale improvement,the current terrain met the water depth requirement of channel scale improvement.Although there was no shallow area,the channel scale still needed to be further increased,mainly by removing some built wing dams.The maximum and minimum flow velocities in the channel were slightly reduced after the wing dams were removed,while the channel water depth still met the requirement of planning.