Influence of cohesion on scour around submerged dike founded in clay–sand–gravel mixtures

Abstract

This study presents the influence of cohesion on scour depth around submerged spur dike founded in the mixtures of cohesive sediment consisting of clay–gravel and clay–sand–gravel. Studies related to scour around submerged dike founded in such type of cohesive sediment mixtures are not reported in the literature to best of our knowledge. All experiments were conducted with singular submerged spur dike under clear water flow conditions. The process of scour around submerged spur dike founded in clay–gravel/clay–sand–gravel mixtures was found significantly different from that of cohesionless sediments. The process, geometry and scour depth around submerged spur dike in cohesive sediments were significantly affected by clay percentage and unconfined compressive strength of cohesive sediment mixtures. Relationships are proposed for the assessment of scour depth at nose and, at the wake of submerged spur dike in cohesive sediments mixtures. The proposed relationships give satisfactory agreement between observed and calculated values.