Paper Title:Development of Working Model for Ogee Profile Spillway Using Steps and Roller Bucket for Enhancement of Energy Dissipation

Abstract

The terminal structure of a spillway plays a major role in dissipating specific energy of excess flood to safeguard the river channel and downstream structure. The ogee profile spillway is hydraulically efficient, structurally stable and more adequate to dispose excess flood effectively on downstream end of river channel. This spillway will be helpful to control the erosion, scouring and pondage if suitable energy dissipater provided at terminal structure. Due to high discharge of excess flood there are chances of causing erosion on Spillway bed, which is a major problem to affect the spillway capacity. Excess air entrainment causes positive pressure on spillway bed and helpful to achieve maximum energy dissipation by replacing ogee profile by steps. Therefore the above problems are rectified by developing the working model on ogee spillway with consideration of combined effects of steps and roller bucket etc. In this present research the experiments are performed in a range of discharge 0.0052-0.0063 m3/s with different devices on developed model at 4 – 6.5 m head etc. It is observed that the ogee spillway with combination of plain roller bucket, steps and stilling basin device achieved 80.24 % energy dissipation and maintained 0.23 m tail water depth in stilling basin with Froude number 5.53.Therefore it is concluded that this device is found to be best suitable energy dissipating device to overcome the spillway problems by enhancing maximum energy dissipation.


Keywords:Ogee spillway, terminal structure, roller bucket, steps and energy dissipation etc.