三峡工程大江截流戗堤进占与通航关系的研究

Study on the relation of river closure dike advancing and navigation for the Three Gorges Project

在三峡工程大江截流期间，戗堤口门河段束窄率为４６％至３５％，通航问题面临着严峻的形势。通过水工模型试验和原型观测，首先探明了施工河段为急弯水流，戗堤口门区主流呈“Ｓ”型流路，导流明渠主流经“复式断面”调整而居于中偏左部位。经由口门和明渠下泄的两股水流在明渠下游口门区交相激射、顶托。水工模型试验进一步对戗堤进占程序和方式进行了优化研究，并对若干关键性局部水流边界进行了整治，从而使得局部碍航流态得以改善，流速的纵横向分布趋于合理，形成了新的适航线路。自航船模试验成果表明：最终付诸实施的大江截流施工布置以及戗堤进占程序和方式可以满足通航设计要求。施工现场的原型观测表明：水工模型和自航船模试验取得了预期效果。

During the river closure of the Three Gorges Project, the river contraction rate in the section of dike mouth is 46% to 35% so the navigation faces a difficult situation. Through the hydraulic model test, prototype observation and optimal study on the program and ways of dike advancing, some key local flow boundaries have been treated to improve local flow regimes which is obstructive to navigation, and to make the flow velocity distribution reasonable so that it can form a new suitable navigation route. The results from the self propelled ship model show that the final construction arrangement of river closure and the dike advancing sequences and ways could meet the requirements of navigation design. The prototype observation in the construction site shows that the tests of hydraulic model and self propelled ship model have gained the expected results.