| Autor: |
Fael, Cristina Maria Sena, Simarro-Grande, Gonzalo, Martín-Vide, Juan-Pedro, Cardoso, António Heleno |
| Zdroj: |
Water Resources Research; 2006, Vol. 42 Issue 10, pn/a-n/a, 12p |
| Abstrakt: |
New clear-water tests on abutment scour are presented. Thirty-one tests with sand bed and nine tests with lightweight pumice bed were carried out in a 28-m-long, 4-m-wide flume. Tests typically lasted for 1 week or more. Vertical-wall abutments with length-to-depth L/ d ratios from 9 up to 36 were used. Other test campaigns in the literature are added to the data, focusing on abutments with 2 < L/ d < 100. The critical flow for scour inception at the abutment nose is found to decrease as L/ d increases. The whole data are analyzed for searching the equilibrium scour depths with different methods. The slope change in the plot of scour depth against the logarithm of time is the method selected. For the group of tests run close to the threshold condition, some trends regarding the dimensionless equilibrium scour depth are (1) dependence on the bed material specific gravity in the sense that pumice tests produce less scour and (2) increase of the scour depth as L/ d increases. Finally, the morphology of the scour area in terms of volume and plan dimensions is given by new regression equations. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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