Numerical Simulation Study On The Erosion Of Abutment And Pile Foundations Under The Impact Of Water Flow

Bridges,across rivers,whose piles and abutments occupy part of cross section of rivers during use,so that Hyper-concentrated flow will have an effect on the erosion of the piles and abutments.However,few researches focus on bridge erosion at the present stage.The understanding of local erosion mechanism and theoretical researches are still relatively limited.In order to understand the mechanism for further,this paper made a simulation to study the erosion of piles and abutments.The main research contents and achievements are as follows:(1)By using the FLUENT software,the erosion distribution of piles and abutment was simulated,and the vulnerable parts were found out.The influence of flow velocity,the size of particle,the diameter of piles and the shape of the abutment on the erosion wear was also studied.The result shows: Erosion wear is mainly concentrated in the edge of the upstream surface of the abutment,the joint of the upstream surface of pile foundations and abutment,and the inside back surface of piles.The flow velocity and sediment particle size will not affect the distribution of erosion of the bridge abutment and pile foundations,which will only affect the erosion degree.Compared with the rectangular pile cap,the eight side cap and the pile foundation,the elliptical cap and the pile foundation have a better ability of ability erosion.(2)Some basic theories of ANSYS/LS-DYNA software was introduced,and the erosion model of concrete was established.In this paper,the failure characteristics of concrete material attacked by sediment particles was analyzed,the influence of attack angle,the size,the velocity and the shape of particle to the erosion were studied.The law of concrete failure and the erosion characteristics of steel fiber reinforced concrete were researched.The result shows: The erosion failure of concrete is mainly caused by the formation and expansion of cracks,and the erosion will be the maximum when the erosion angle was 90 degrees.Both the velocity and the size of particle will aggravate the erosion of concrete.Compared with ordinary concrete,steel fiber reinforced concrete performs better on erosion resistance.By studying the erosion of bridge abutment and pile foundations,it can provide some reference for human beings to make a detection and protection.