Numerical Simulation Of The Huai River Waterway Nearby The Sea Railway Bridge And Research On The Calculation Method Of Local Scour Around Bridge Pier

Combining with the engineering example of the Huaihe River waterway to the sea railway bridge, this paper establish a two-dimensional hydrodynamic mathematical model, selects four different shapes and sizes of mound and three kinds of span, The influence of the size and span of the pier to the flood water level are studied under three different conditions of the recent design flood, forced flood and long-term design flood, the size and shape of pier are optimized. According to the result of numerical simulation of flow field around piers, there representative formula at home and abroad are chosed to calculate the local scour depth of pier, the deviation of three kinds of formulas are analyzed. The main research results of thesis are as follows:(1)The relative error of the average rate of water level of inlet boundary in computational domain were0.022%,0.034%and0.091%with the established a two-dimensional hydrodynamic mathematical module in three different conditions, it shows that higher precision can be achieved by this method.(2)Pier shape and size and span have a certain impact on the water near the pier, under the condition influenced most by back water, Four different shape and size of the pier at the inlet boundary are computed from0.027m,0.024m,0.018m,0.017m, the relative water level were0.1889%0.1679%0.1259%0.1189%, The average backwater of three kinds span at the inlet boundary were0.017M,0.015m,0.013m, average relative water level of the inlet boundary were0.1189%,0.105%,0.091%. According to principle of the average relative water level of inlet boundary not more than1‰, selected span of66.4m, semi-circular head and tail, of pier of770cm long,350cm wide for the eventual adoption of the form.(3)The clay scour around pier is calculated in different flood conditions by domestic design formula, modified code of Zhu Bingxiang and formula of the former Soviet union, the maximum deviation of the result of local maximum scour depth around pier of thalweg and beach by using domestic design formula, modified code of Zhu Bingxiang is17.79%and72.74%,14.01%and-33.96%. by the formula of the former Soviet union, the deviation by the three different method is lagre.