Evaluation of the impact of nanomaterial on local scour around bridge piers

Bridges are a vital element of the infrastructure of a country. There are many reasons that lead to bridge piers failure and scour is one of the most problems against the bridges, moreover localized scour combined with general riverbed degradation, and therefore it's important to improve the soil under the piers. Several methods can be used to improve the soil under the bridge piers. Three dimensional numerical scour modeling was developed to simulate the local scour around bridge piers under using of Nano clay technique using finite difference method ANSYS FLUENT software. In this study Nano Clay was used to reduce the maximum local scour depth around circular bridge piers. Three different bridge pier diameters were used with different percentages of Nano clay of 0, 3, 5, 10, 13, 17, 20 and 25 respectively in the sand. The effect of Nano clay on local scour was investigated at different percentage as scenario in the mixture of sand around bridge pier. The model depending on experimental data started with zero percentage of Nano clay as scenario (sc1). In this scenario, the maximum local scour has been high. Addition of Nano clay reduced the maximum local scour. The simulation results show that the maximum scour depth changes with diameter of pier and the percentages of Nano clay. The optimum percentage of Nano clay in the mixture of sand was found as 13% which is scenario 5 (sc.5), where the maximum local scour for pier diameter of 11.1 cm reduced by 1.60 cm compered to scenario 1 (sc1).