عنوان مقاله [English]
An important factor in increasing the scour around bridge piers is the accumulation of debris and trees. The effect of discharge, water depth, location of the debris, thickness, diameter and shape of the debris on pier scour been studied experimentally. 45 samples in the laboratory hydraulic and hydraulic structures, water engineering shahid Bahonar University of Kerman. The results showed that the maximum scour depth increases with increasing water depth less discharge occurs. The thickness and diameter debris on pier scour effective and maximum scour depth increases. The location of debris on the scouring effect. If the water level up to the debris 15hsub"> , Water depth is 15h"> , In the range 0< 15hsubh"> < 0.3 with debris submerged increase the scour depth increases. For 15hsubh"> >0.3 scour reduced by increasing the submergence. The shape of the debris can affect scour, debris rectangular, cylindrical and triangular respectively scour more. Accumulation of debris such as branches and trunks of trees around the pier of the bridge scour increases about 90%.