INFLUENCE OF PILE GROUP DENSITY ON MINIMIZING LOCAL SCOUR OF A DOUBLE SPUR DIKE GROUP

Abstract

The present study is about flow structure and bed deformation around a group of double spur dike with the main purpose of how to reduce the local scour in the neighborhood of a conventional-type spur dike. Four types of submerged pile group, with different densities were installed in the same area at the upstream adjacent of the first spur-dike. The corresponding effects of each new model on flow and bed deformation mechanism were compared with those of the conventional spur-dike group. Flow velocity was reduced at the neighborhood of the first spur dike in the cases with a pile group. Local scour was also reduced both in depth and volume. With a decrease of the pile density flow patterns became more similar to the conventional case, local scour depth and bed erosion in the spur-dike field were increased. The promotion of sediment deposition in the spur-dike field was observed in the cases with medium and lower pile density, respectively.