By using three-dimensional numerical model, numerical analysis about local scouring around a pier was carried out. The method of the analysis is three-dimensional LES. The main objectives are to obtain the data of innovative prevention measure that is effective for the actual rivers. The prevention measure is to attach or bury the small-scale structures at the front base of the pier, and to change the current and reduce the scouring depth. Before now, many investigations are carried out, and several important results for the abatement of local scouring were clarified. However, they were the effects under the limited conditions in experiments and numerical analysis. In present paper, the small scale structure is attached or buried in front of the bridge pier and the effect of prevention measure to local scouring is considered. The scouring depth that the small scale structure is attached and buried is smaller than it that the small structure is only attached.
