|
Abstract
|
Details of an experimental study for 22 clear-water scour tests around bridge piers are presented in three combinations of flowaltering
countermeasures against bed erosion. The combined countermeasures are as follows: (1) berm and geometry; (2) berm,
geometry, and centered slot; and (3) berm, geometry, and off-centered slots. First, four different cross-sections were selected for
the model piers (A series). The results of this group have shown that the lenticular model can decrease the scour depth
remarkably. The efficient height of a berm was then determined through B series of tests for circular cylindrical model pier.
Then, it was found that the first combination (C series) could not decrease the bed erosion significantly. Also, the second
combination (D series) mainly decreased the scour depth only in the circular and round-nosed rectangular geometries. Finally,
the third combination (E series) used for the first time with considering its structural aspects can be considered as the most
effective countermeasure only for the common geometries of the model piers. The results showed that the combination of
different countermeasures would not be an efficient tool for all geometries of model piers.
|