A Review of Applied and Optimal Spillway in Dam Construction Based on Effective Dynamic and Kinematic Parameters

Overflows are generally installed to drain excess water or floods that the volume of the tank can not store. In diversion dams, overflow is used to bypass or divert current in excess of system capacity. Demolition of many dams occurs due to incorrect design or insufficient overflow capacity. Proper spill design is more important in gravel earthen dams than in concrete dams. because the probability of destruction of earthen and gravel dams due to water passage is much higher than concrete dams. In the present study, a comprehensive review of the types of applied overflows based on effective dynamic and kinematic parameters was performed. Also, definitions and summaries of different types of free overflows were shot, siphon, stepped, congressional, lateral, tunnel, circular crown, peak, lotus or tulip. Then, the mechanism of vortex formation was introduced and an overflow appropriate to this phenomenon was introduced. The results of these cases showed that the application of lotus or tulip overflow in flood areas with high discharge has better performance.