河口整治技术在长江口深水航道治理工程中的若干新进展

New Progress in Estuary Regulation Techniques in Yangtze Estuary Deepwater Channel Regulation Project

长江口深水航道治理以河口整治为基础,主要是通过整治建筑物使航道所在的汊道获得固定的边界,稳定的流场,从而调整地形,消除汊道内的拦门沙浅段。不能简单地将设计思想归结为束狭河床,提高流速。预测工程后的流场、地形以及航道回淤量,可采用正压模型;河床调整向不利方向转变的条件应由数值模拟或物理模型试验给出,事先设定某种分流比界限是困难的。已经完成的一期和二期工程的效果表明,工程设计和施工方案是先进、成功的。包括总体设计、护底及结构设计和施工成套技术,以及生态保护等在内的一系列关键技术的突破,标志着我国在河口整治技术和方法上已取得明显进展。

Estuary regulation is the major concern of the Yangtze estuary deepwater channel regulation project. The project is aimed to adjust the river-bed pattern and to eliminate the bar section favorably on the selected passage where the channel is being deepened, by means of forming a fixed boundary and a stable current field with the help of regulation structures. The design principle should not be simply understood as to narrow the breadth of the passage and to increase the current velocity. Barotropic mode technique could be used to predict the current field, river-bed pattern and back-silting after the implementation. Because it is difficult to pre-determine a certain diversion ratio of flow as a criterion, mathematical model and physical model could be applied to compute the conditions of unfavorable river-bed deformation. The results of the completed phase Ⅰ and phase Ⅱ show that the general design and construction scheme of the project are advanced and successful. Great technical breakthroughs have been made on the general design, bottom-protection, construction and environmental protection etc. , which means that a significant technical development on estuary regulation has been achieved in China.