The 1-D Numerical Simulation Of Bridge General Scour

The calculation of bridge scour is very important in bridge design. Choosing the bridge site, arranging the bridge span and calculating the depth of the bridge basement are relevant with the bridge scour. Because of the complexity of sediment movement and imperfect of the mechanism of river bed evolution, the accuracy of bridge scour modeling is not high, so the method needs to be further improved. The thesis first systematically represents the predecessor's research achievements; then, referring to the basic law of hydraulics and river dynamics, utilizing the method of finite difference, dispersing stream and sediment control equation, the thesis built 1-D suspension load non-uniform sand numerical model. The thesis realize mutation of bridge cross section width after contraction by changing the river reach slowly, increase the intensity of transition section's mesh during calculation; the model considered the non-equilibrium transport of non-uniform suspended load and sorting of the bed material, but didn't consider the motion of bed load. By utilizing the numerical model, not only the bridge scour and hydraulic element correlated with the bridge can be calculated, the fluvial process near the bridge can be calculated too. The thesis analyses the rationality of the numerical model with a simplified river model. All of the result indicated that the numerical model is reasonable. At last, the thesis proved the rationality of numerical model by comparing the observation datum of the fixed cross-section in the Changjiang River near the Zhicheng Bridge with the calculation results.