复杂心滩通航河段不同角度碛首坝对航道条件的影响

Effects of first moraine dam with different angles on navigation condition in complex diara navigable river

长江上游河段多为基岩和卵砾石河床,常见心滩、浅滩及边滩等复杂边界碍航河段。由于工程实际需要及航道整治要求,经常存在采砂坑、开挖航槽、修筑碛坝等改变局部河道边界的情况。以长江上游占碛子河段为例,建立向右偏转0°、5°、10°碛首导流坝数学模型,分析表明:0°碛坝引起的水位壅高流速增幅和分流比变化均较小,对占碛子浅滩影响较小;5°碛坝对主槽分流比和航道通航水深及流速的优化更加明显,通航效果更优;10°碛坝对主槽通航条件的改善明显,对流场改变较大,引起了明显的河势演变。为长江上游复杂通航河段航道整治工程的设计和研究提供参考。

Due to the bedrock and gravel bed of bstructing reaches are common with the diara, shoal and the upper reaches of the Yangtze River, the navigation- beach, which are of complicated boundaries. To meet the needs of the actual project and waterway regulation, there always exists a sandpit, excavation of navigation channel, the construction of the moraine dam and other ways to change the local river boundary. Taking Zhanqizi reach for example, we establish the mathematical model of the first moraine diversion dams which turn right to 0°, 5°, 10° respectively. The result show that the 0° moraine dam causes smaller stage rise and diversion ratio change, and it aas less influence on shoals of moraine son; the 5° moraine dam has an obvious effect on the optimization of the nain channel split ratio an water-ways navigable depth and flow rate, and the navigation effect is better ; and the 10~ noraine dam has a remarkable effect on improving the navigation condition on the main channel, and it changes ~eatly the flow field, and thus causes significant river changes. The research result may serve as reference for providing a reference for the design and research of the regulation engineering of complicated navigable channel on he upper reaches of the Yangtze River.