Comparative evaluation of energy dissipation over short stepped gabion and rigid spillways

摘要

The energy dissipation in a gabion stepped spillway is compared with that of a rigid structure. The prototype had one, two or three steps, and models of rigid and gabion spillways with similar geometric dimensions were tested. The results showed that stepped gabion structures in one, two and three step modes, on average, increase the energy dissipation as compared with the rigid structures. In addition, the increase in flow rate reduced the efficiency of energy dissipation. Furthermore, in gabion spillways increasing the number of steps to three increased the energy dissipation. The effect of the second step on the rate of increase in the efficiency of energy dissipation was higher than the third step. The results indicated the high impact of throughflow in the gabion spillways on the energy dissipation. The second and third steps increased the energy dissipations compared to the one-step spillways; however, in the third step, the energy dissipations decreased slightly.