Author(s): Freddy Florez-Otero; Jaime Ivan Ordonez
Linked Author(s): Jaime Iván Ordóñez, Freddy Florez
Keywords: No Keywords
Abstract: The determination of the relationship between the local scour scale, (hsr), and the vertical scale, (hr), is very important when are using movable bed physicals models for hydraulic design purposes. Prototype-model experiments have been conducted under live-bed scour conditions on the Hydraulics Laboratory at the National University of Colombia at Bogota. The Research Unit consists of two laboratory flumes, one called Prototype, (sand or gravel-bed) and the other Model, (sand or Bakelite-bed), which is used to reproduce the scour experiments conducted in the Prototype but on a reduced scale, (Lr =5), (4≤hr≤14), (20≤Qr≤100), (0.1≤Qsr≤200). Experiments were conducted with and without distortion of the Froude scale, and the scour depths around two hydraulic structures were measured: a vertical wall spur dike inclined 30° with the bank, and a circular pile in the center of the channel. For Gravel/sand models vertical scour scales remained equal to vertical model scales, while for Sand/Bakelite physical models the relations obtained were that 2 hsr ≈ hr, Lsxr ≈ Lr (spur dike) and that the longitudinal scale (Lsyr) depends on the type of structure used. Predictive equations for hr, hsr and Lsyr were also obtained using hydraulics and sedimentological scales.
Year: 2009