Dissipation of Energy of Flow by Conventional Type of Gabion Weir

Abstract

The present study aimed to investigate the effect of using the conventional (rectangular) shape of gabion weir in dissipating the energy of flow. For that a series of laboratory tests (25 experiments and 194 test runs) were conducted on the gabion weir by using of a laboratory flume of 12 m long by a cross section of 0.3 m width, and 0.5 m height to test five different lengths of the weir, (40 cm, 60 cm, 80 cm, 100 cm, and 120 cm), with five respective monosized samples of natural quarry gravel with diameters (9.5-14) mm, (14-19) mm, (19-25) mm, (25-37.5) mm, and (37.5-50) mm. The tests were conducted for a range of discharge (0.7-15.0) l/s. Dimensionless analysis was used to analyze the data by using Buckingham Pi-Theorem to find the relation between the difference in energy of gabion ends and the unit discharge. Beside, a comparison discharge was chosen to find the relation between the difference in energy of gabion ends and the other variables. Results of experiments showed that the difference in energy increase by increasing both the unit discharge and the length of the gabion weir and decrease by increasing the equivalent diameter of the gravel sample.