Experimental and theoretical investigations of scour at bridge abutment

Numerical and experimental studieswere carried out to investigate the effect of different contraction ratios and entrance angles of bridge abutment on local scour depth. a 3-d numerical model is developed to simulate the scour at bridge abutment. this model solves 3-d navier–stokes equations and a bed load conservation equation. the k-ϵ turbulence model is used to solve the reynolds- stress term. in addition, themodel verification ismade by comparing the computed results with existing experimental data. the results show the ability of the numerical model to simulate local scouring at bridge abutments for different contraction ratios and entrance angles of abutment with high accuracy. the determination coefficient and mean relative absolute error, in average, are 0.95 and, 0.12, respectively.