Simulation Research Of COD Concentration Under Different Construction Way At Yangcheng Lake Bridge Of The Beijing-Shanghai High Speed Railway

The beijing-shanghai high-speed railway once built is the longest and highest standard high-speed railway since the founding of the largest construction project investment. Yangcheng Lake in jiangsu province is one of the important freshwater lakes, is also one of suzhou important potable water source. There is total of seven across the Yangcheng Lake by Beij ing-Shanghai high speed railway, the length of total line segment is 5900m, there are 181 piers in the Yangcheng Lake water. The Beijing-Shanghai High Speed Railway Bridge steps over in DK1226～DK1263 range of water source protection areas by the Yangcheng Lake, which may has some effect on lake of the original field of COD concentration. In the design process of the bridge, construction unit mainly put forward two construction scheme, namely:double row dams cofferdam construction schemes and steel trestle construction scheme. After much argument, construction unit choose the double row dams cofferdam construction plan finally.In this thesis, the Beijing-Shanghai high-speed railway construction technology across the Yangcheng Lake Bridge and water quality in the construction area cross the lake, the lake bottom topography and geology, weather and other information as the research base, water quality with Delft-3D simulation software techniques, contrast Yangcheng Lake section of the original water quality, double dam cofferdam construction phases and stages of steel trestle lake water concentration of COD, construction concluded in the wading water environment under the premise of the concentration of COD impact construction methods. Paper simulation results can be important for large bridges across bodies of water accumulated some experience in environmental research, as well as future high-speed railway in China's large and small wading road construction environmental protection work of some guidance.In this thesis, the water quality through the use of reasonable simulation software simulation study finds that the Beijing-Shanghai high-speed rail bridge across the double Yangcheng Lake dam cofferdam construction and steel bridge construction on water quality in Yangcheng Lake, the impact of different degrees, after a comparative analysis, double dam cofferdam construction causes less impact on water quality relative to the steel trestle.