Study On Improvement Measures Of Navigation Flow Condition Of Existed Cascade Junction

In the past, the inland junction construction in China often gave priority to the benefit of flood protection, power generation and so on. The attention which was given to navigation construction was insufficient. Together with the lack of channelization experience and the problem of management system, a group of navigation obstruction gate dams were appeared. Yuanshui river, which is planned as the main waterway navigation complex, is one of the seven branches of the Yangtze river. But there have a great deal of technical problems from the practical effect of Wuqiangxi hydroelectric power station and Lingjintan station. In this paper, based on the research results of navigation obstruction problems in the lower reaches of Yuanshui river, a deeply study of the improvement measures of navigable flow condition for the lower approach entrance area of the existed junction lock was carried out according to the physical model and mathematical model. The results obtained were as follows: (1) The cause of beach formation in the lower reaches of Lingjintan junction lock and its navigation obstructing characteristics had being known in a deep-going way, then the relevant regulation principle was put forward. (2) The improvement measures of navigable flow condition for the complex rapids were obtained on the basis of several regulation project tests in Lingjintan junction lock. (3) Factors affecting the navigation flow condition for the lower approach entrance area of the Wuqiangxi junction lock were deeply analyzed.Aiming at the navigation obstructing characteristics in this area, the scheme adopting floating embankment was proposed to avoid the oblique flow effect in range of ship draft and raise the navigation discharge. (4) The flow motion law and the influence of unconstant flow due to daily regulation of the Wuqiangxi junction on flow conditions were analyzed, and the economic and feasible waterway regulation measures for the fluctuating backwater area between Wuqiangxi and Lingjintan were presented.