HYDRAULIC PERFORMANCE OF GROINS AND THEIR EFFECTS OF THE BANK AND BED PROTECTION

A 2D numerical simulation model of flow and bed evolution was developed which can evaluate the influence of groins to channel flows, as well as the shift effect of deep scouring separating from the banks in bend channels. In the present method, a hypothetical bed level concept is conducted to express the decrease of flow area due to groins, instead of the true bed level. And energy loss in the influenced region around groins is expressed by an added bed friction coefficient. The validity of the method is verified by the comparison of calculated results with experimental data. Furthermore, from the practical point of views, some discussions and considerations are made on the prediction of groin's effect, associated with the proper size and arrangement of groins in river engineering works.