Assistant Professor, Department of Civil Engineering, Imam Khomeini International University
Abstract
The existence of vertical bridge supports along the river causes three-dimensional flows and can cause scour at the bridges and eventually damage the bridge. In cases where deep foundations are not used, the level of vulnerability increases. These bags are often applied to single-span bridges and preventive measures such as covering the bed with durable materials such as rock. The purpose of the present study is to provide a conceptual model of localized bed shear stresses on heterogeneous bed roughness at bridge mouth. The adaptation of the flow to changes in the roughness of the rock material compared to the bed material results in an increase in bed shear stress in the unprotected bed material and eventually the scour depth becomes narrower than that without rock protection. The numerical model also confirms the hierarchy. The adaptation of the flow to changes in the roughness of the rock material compared to the bed material results in an increase in bed shear stress in the unprotected bed material and eventually the scour depth becomes narrower than that without rock protection. The numerical model also confirms the hierarchy.