Author(s): Serife Yurdagul Kumcu; Mustafa Gogus; Mehmet Ali Kokpinar
Linked Author(s): Mehmet Ali Kökpinar
Keywords: Local scour; Collar plate; Abutment; Scour location
Abstract: The growth of principal vortex can be arrested by forming a rigid surface around the abutment with a collar. Although experimental studies showed that the scour holes formed at the upstream side of the abutment, if collars were used it was observed that the maximum scour depth was routed to the downstream of the abutment. In this study, a series of experiments were carried out for the abutment lengths are La=15 cm, 20 cm and 25 cm. For each case a collar plate was placed at the vertical location of Zc=-5 cm on the abutment. As the experiments were conducted with collars, it was observed that due to the presence of the collars other scour holes developed at far downstream of the abutments. However, the maximum depths of these scour holes were smaller than those observed at the faces of the abutments when they were tested without collars. To describe the location of these maximum scour depths, the angle ξ is defined. ξ varies between 20. 40o-27. 30o; 28. 10o-32. 50o and 32. 8o-44. 10o for the abutment lengths of La=15 cm, 20 cm and 25 cm, respectively. Although these scour depths are higher than those recorded at the abutment face when it has a collar around it, they are still lower than the maximum scour depths, which are obtained from without-collar cases.
Year: 2013