University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 47 89 2018 02 20 Evaluation the Performance of Bed Sill, Collar and Their Combination in Scour Protection of Cylindrical Bridge Pier Evaluation the Performance of Bed Sill, Collar and Their Combination in Scour Protection of Cylindrical Bridge Pier 113 121 7201 FA Nazanin Shahkarami Faculty of Engineering, University of Arak Journal Article 2018 03 12 One of the main causes of the destruction of marine structures, is creating erosion in its pier foundation. The uncontrolled spread of scour hole undermines the foundation and thereby will threaten the entire structure. In this study, the performance of countermeasure strategies include bed sill, collar and then combination of them were evaluated. Experimental assessment for cylindrical pier has been conducted under the clear water condition. Based on the recommendations resulting from the studies reviewed, bed sill was attached to the downstream side of the pier, the width of the channel, vertically from floor to sediments and circular collar with an outer diameter equal to 3 times the pier diameter, was installed in the bed level. Also in the combination method the integration of last two solutions was used, while bed sill was placed tangent to the downstream of collar. One of the main causes of the destruction of marine structures, is creating erosion in its pier foundation. The uncontrolled spread of scour hole undermines the foundation and thereby will threaten the entire structure. In this study, the performance of countermeasure strategies include bed sill, collar and then combination of them were evaluated. Experimental assessment for cylindrical pier has been conducted under the clear water condition. Based on the recommendations resulting from the studies reviewed, bed sill was attached to the downstream side of the pier, the width of the channel, vertically from floor to sediments and circular collar with an outer diameter equal to 3 times the pier diameter, was installed in the bed level. Also in the combination method the integration of last two solutions was used, while bed sill was placed tangent to the downstream of collar. https://ceej.tabrizu.ac.ir/article_7201_4973cc1b0bb6d5d364d71aded9c7bffe.pdf