Study On The Hydraulic Characeristics Of Bridging Underwater Platform For Opening Reservior Sustained Rapids Area

Yangtze River as the first river running through east and west China, which connecting the southwest, central, east three major economic zones to be a transportation artery. Since the late 90 s of the last century, Yangtze River shipping has become the most important main axis of economic and productivity layout with its fast recovery. Recent years, states relying on the Yangtze golden waterway to promote the economic development zone, building a strategy along the economic circle, putting forward higher requirements on the navigation of Yangtze River Waterway ability. And the current rapids between the Three Gorges and Gezhouba(hereinafter referred to as "between two dam") is not conducive to increase the Yangtze River navigation-channel overall conditions and shipping channel level, Hinder the Yangtze River shipping capacity into full play. Combining current rapids remediation between the Two Dams, traditional programs regulation effect is difficult to completely. Therefore, we propose a new reservoir rapids regulation ideas and methods- Overhead underwater platform to open slow flow area.Flume experiment and simulation technology are used in this paper to conduct a preliminary study on flow characteristics and engineering applications of overhead underwater platform, the main contents and results are as follows:(1) According to the reservoir rapids materials between the two dams, combining the characteristics of the reservoir rapids areas, summarizing shortages of the traditional remediation methods to Gorges rapids’ regulation.(2) For the hydraulic characteristics of deepwater rapids in reservoir, Completed selection of flume experimental model parameters overhead underwater platform and reasonable developed combinations of test conditions.(3) After flume experiment, established an exponential formula of surface velocity variation v1 e 、v2e, with deep reduction ratiohe, narrow beambe and flow rate conditions Fr, the platform occupies rateAe; Proposed subcritical flow width L and established its relationship with he 、be 、 Fr; According to the measured datas, a preliminary analysis of the relationship between bottom velocity and deep reduction ratiohe; combined current backwater formula, analysised to determine the main factors influencing the steep slope of imports, and established a relationship between the local slope of inlet section J and the key factors Fr.(4) Determining the optimal program conditions according to optimization design ideas, alternatives demonstrated using the platform roughening, plus pile can improve the platform flow’s reduction effect, platform flow reduced effect could increased by 10%.(5)Using numerical simulation, adopting overhead underwater platform solution to do project renovation & numerical study on reservoir rapids section(Xitan). Through the rational layout platform, Alternatives made Xitan’s rapids-forming flow from 35000 m3/s increased to 44000 m3/s.(6) There are two programs design ideas Proposed on the overhead underwater platform and suspended platform, and program’s feasibility has been preliminary considerate.