EXPERIMENTAL STUDY ON THE CORRELATIVE PROBLEM OF DREDGING SHOALS IN A TYPICAL CURVED CHANNEL OF THE MIDDLE YANGTZE RIVER

摘要

Dredging on navigation obstruction shoals is often implemented at the middle reach of Yangtze River which contains a series of curved channels. However, the aggredation usually happens for the unconspicuous bending flow characteristic in these reaches. So, pre-dredging projects are needed to build up firm concave boundaries of the flow. This will enhance the bending characteristic of the flow, reduce the aggredation at shoals, and establish the foundation for the future dredging project. A typical pre-dredging project in bending channel is introduced in this paper, taking the project in Dai-Jia-Zhou section as an example. The Dai-Jia-Zhou section is a bending reach containing the above mentioned phenomenon, in order to reduce the aggredation after dredginga revetment is used to protect the concave boundary. This paper carried out an experimental study on the navigation channel regulation of Dai-Jia-Zhou section in the middle Yangtze River, which presents different schemes for the revetment length on the concave bank. An optimal revetment length is propounded after a comparison among 4 schemes on flow field, split ratio and evolution of a navigation pool, which establishes a foundation for shoal dredging in the right branch of the Dai-Jia-Zhou section with the enhancement of the hydrodynamic characteristics of curved flow.