三峡工程运用初期石首河段冲淤试验及河势控制方案研究

Physical Modeling of Fluvial Process and River Regime Control in Shishou Reach of Yangtze River at the Initial Stage of Three Gorges Project

利用长江防洪实体模型动床模型试验,研究了三峡工程运用初期不同时期石首河段的冲淤变化规律,并预测其河势变化趋势;针对该河段出现的新情况进行研究分析,提出了该河段的河势控制方案。研究结果表明:三峡工程蓄水运用至2022年末,该河段总体河势与近期基本一致,依然维持目前新生滩左汊为主汊、左汊内左槽为主河槽的分汊格局,但局部河势仍有一定程度的调整变化。该河段的河势控制初步思路为:对深泓近岸及主流顶冲的险工段采用护岸守护,包括对已建护岸工程的加固及未护段的新护;另外,根据河势调整趋势,对局部洲滩进行守护,以稳定目前较为有利的河势格局或防止其向不利河势方向转化。

Physical modeling tests were performed to study the fluvial process in Shishou reach of Yangtze River in the purpose of predicting the river regime tendency and proposing river regime control plans for the changes at different stages of Three Gorges Project（TGP）. The results reveal that until the end of 2022, apart from some local changes, the overall river regime of Shishou reach will generally remain the same as that at the present, which pres- ents a braided pattern with the left branch of Xinsheng shoal, a newly developed shoal, as the dominant and with the left channel in the left branch as the main channel. The preliminary plan of river regulation projects include bank protection works, either reinforcements or new constructions to be carried out at vulnerable spots along the riv- er bank which are close to the thalweg or heading to the main flow. Additionally, to maintain the present regime or prevent it from deteriorating, bank protection projects will be constructed at some local sandbars or beaches based on the tendency of river regime adjustment.