Partial Scouring Test And Numerical Simulation Of Skew Piers

The problem of local scour of bridge piers has always been a difficult point in the design and construction of bridges.Most of the existing piers are mainly cylindrical and long cylindrical piers.When studying the flow field around the pier,only the frontal flushing of the water flow is considered,and the river flow direction is not certain.The rivers of most rivers in northern China belong to the wandering river channel,and the bridge pier fixed in the river bed will inevitably An angled bridge pier is formed at an angle with the direction of the river.In this paper,the problems of the skew piers are tested by physical model test and numerical simulation.The physical model uses a 1:100 normal model sink to perform a series of tests on long cylindrical piers with different skew angles.The system observation and analysis of the scouring pit morphology of the pier under different water flow intensity and oblique angle are carried out.The results show that the geometric characteristics of the crater of the skew pier are quite different from those of the orthogonal pier.When the single-width flow is 10m3/(s.m)and the skew angle is 15° or more,the conjugate flushing pit will appear in the pier.When the pier is oblique,a clockwise vortex water flow drop zone will appear on the backwater side,and a partial flushing pit will be formed at the tail of the water-facing side pier.The local scouring depth,volume,and range of the pier will follow the water flow intensity and the oblique angle.The increase and increase of the pier is about 0.7 times the depth of the pier.When the water flow intensity is small,the calculated value of the standard formula is compared with the test value;when the water flow intensity is large,the gauge calculation depth is smaller than the test value,and the reduction is about 0.66~0.92.At the same time,the numerical simulation software was used to simulate the partial scour of the skew piers,and the results were basically consistent with the physical model tests.The detailed analysis of the piers under the 45° angle can be used to clearly observe the flow field distribution and the vortex system.The process of scouring pit formation can also be clearly demonstrated.At the same time,the conjugate scour pits are compared.It provides a reference value for discussing the relationship between bridge pier scouring and water flow.