H Salamat Ravandi, Mh Kharazi Fard, Mr Majdzadeh Tabatabaee,
Volume 7, Issue 2 (3-2014)
Abstract
River bank erosion is a mechanism initiated by soil particles movement due to subsurface flow. This may occur in a soil texture at a critical hydraulic gradient. With regard to the complexity of river bank erosion processes and limited research in this field, it is of significance to investigate and to identify the effective parameters. In the present study, a physical model of a river bank was developed to achieve in-depth understanding of the effects of bank material particle sizes on porous media under various hydraulic gradients. It is concluded that the length of scour hole caused by seepage erosion may depend on the hydraulic gradients as well as Reynolds number. Further, two empirical relationships are derived on the basis of observed experimental results to estimate scour hole length resulted from river bank erosion for laminar and turbulent conditions
Azam Masoodi, Mohammad Reza Majdzadeh Tabatabi, Ali Noorzad,
Volume 10, Issue 2 (11-2016)
Abstract
Subsurface flow contributes considerably to river flow and plays an important role in river sediment loads. This research has been focused on investigation of soil properties and bankstream slope on seepage erosion. For this purpose a series of lysimeter experiments were performed for four different slopes of bankstream by varying the soil grain sizes. The obtained results indicate that Reynolds number in porous medium plays an effective role in depth of scour hole in noncohesive layer. It was observed that the time of beginning of sediment motion decreases with an increase in the soil grain size.
