Effective Parameters on Sediment Trapped in Porous Media

Due to the permeability and economic justification of rockfill dams، these structures have attracted considerable attention for flood relief in many watersheds by engineers. Knowledge of flow hydraulics is necessary for correct design of these structures. In this paper an empirical equation is derived for estimating the trap efficiency. To do lab experiments a tilted flume considering 3different slopes، 3 sediment diameters and 2 porous media have been used. In addition، the influence of sediment injection rate change using 3 injection rates was investigated. The results showed that the trap efficiency is inversely proportional to the Re، S، λ and i. The findings also indicated that an increase of injection rate leads to a slight rise in trap efficiency so that this factor will be reached to a fixed value. The presented relationship is capable to estimate trap efficiency with high accuracy of R2 = 73%.