Research On The Buoy Distribution Scheme Of The Yangtze River Main Channel During The Bridge Construction Period

Bridges under construction on the main channel of Yangtze River are mainly steel box girder type.The longest period of constructing this kind of bridge,which exert a tremendous influence of the main channel navigation,is the construction period of the pier and the steel box girder structure.Depending on the different sizes of the bridge,the construction period is generally ranging from two to five years.In order to ensure the construction of the bridge and the safety navigation,this thesis studies and puts forward the waterway layout and the buoy layout scheme according to the influence of the bridge construction period on the waterway.The main contents and results are as follows.(1)The thesis puts forward the principle of waterway arrangement during the bridge construction period of the main channel of the Yangtze River,and the quantitative analysis is carried out from the study of channel water-depth and width theory.The distribution requirements of buoy under different grades are studied.The key points of buoy distribution in bridge sections are analyzed and summarized.And the reasonable spacing between the buoy of the Yangtze River lower reaches is also quantitatively analyzed.(2)The thesis investigates the function of inland river buoy and the types of inland river bouy lights.The design principle of the buoy distribution in the construction area of the bridge is proposed,and the representative buoy used in the bridge construction area is studied and selected.(3)The thesis analyzes the existing channel status of the engineering section from the aspects of engineering river profiles,riverbed evolution,river natural conditions,flow conditions,channel status,and so on,with two under-construction bridges in the lower reaches of the Yangtze River being selected as engineering cases.(4)According to different construction process and characteristics of cable-stayed bridge and suspension bridge,the influence of bridge construction on waterway is analyzed in stages.(5)With each stage of construction,the scheme of the waterway layout in the construction period of the bridge is designed,and the operational plan of the buoy is built on the basis of it.Especially for the current bridge construction of the main channel of the Yangtze River,under the premise of the current construction technology,the proposed scheme can completely avoid the temporary river sealed route,also ensure the traffic time effectiveness and navigation safety,and provide the reference for the subsequent construction of similar bridges of waterway maintenance.