| In order to keep shipping smooth, the subsection cofferdam, stage construction organization implementation of construction when building comprehensive water conservancy project on navigable rivers. Before the navigation structures play a important role in the whole construction process, usually by coarctation of drainage and navigation, not only that, the shipping line will be changed with construction cofferdam changes. During the construction period,becaused the temporary cofferdam project of the building control some complicated flow phenomenon will emerging,and the flow around, vortex and shear flow frequently, navigation conditions, ship safety issues outstanding. To ensure the safety of shipping, it is necessary to seriously study and analysis of construction period, the flow law of motion and the variation characteristics of, optimizing the layout of cofferdam and river regulation, improvement of traffic conditions, the upgrade to meet the safety of ship navigation safety of maximum navigable discharge.In this paper, based on the Fujian Minjiang Shuikou Hydropower Station dam water level control project, the focus of governance for the shipping building before the completion of the two stage cofferdam layout and temporary channel, according to the principle of fluid mechanics, the flow characteristics and transform construction sectionsand bed characteristics, a series of engineering optimization measures is proposed. Such as flat bottom, reduce the bottom elevation, ease the smooth connection the longitudinal river and shorten the length of longitudinal cofferdam upstream end, arc type connection transverse and longitudinal cofferdam to improve the construction of navigable flow condition. Mainly from the river water level, water surface slope, the maximum velocity of flow characteristics, optimization of cofferdam and layout temporary channel regulation of test and calculation by the calculation method of physical model test and numerical simulated. Results show that, through the optimization and after construction of governance, the construction of the two phaseof the maximum flow to improve the safety of navigation of diversion by original 1686m3/s to 3934m3/s, the Engineering Dam about 9.0km Shuikou project at the entrance area of the approach channel due to the river water level, water cut under low power discharge is not less than 2344m3/s in order to meet the currentindicators to flow 1686m3/s import channel and construction of ship safety lock when meet the navigation deviation phenomenon is solved. The Shuikou Power Station discharge between 2344m3/s and 3934m3/s, which can meet the navigation of ship draft minimum safety requirements, and to ensure that ships smoothly through the narrow river, realize the real meaning of navigation in the construction period. The research results of this paper applies not only in Shuikou Dam water level control project navigation during construction period, but also a guiding significance for similar engineering navigation during construction period. |
