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Subject Areas : watere sciencesRuholah mansouri yekta 1 * , Hamid Kaykha 2 , Bfhrooz Dahanzadeh 3 , Majid Razaz 4
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2 - Department of Water, shoushtsar Branch, Islamic azad university, shoushtar,Iran
3 - Azad aslami university -branch of shooshtar ,water science college.
4 - water engineering department, water science faculty, Islamic azad university, shoushtar branch, shoushtar
Keywords: Goblet-Shaped Projectiles, Shallow Depth, Dynamic Pressures, Plunge Pool,
Abstract :
In investigating goblet-shaped projectiles in dams, forces that their exiting jet flow exerts in the impact site with the downstream bed, because scouring or failure of bottom concrete slab, This phenomenon compared to other structures, requires more investigations and studies. Determining dynamic pressure properties in the impact site in various conditions, allows us that in case of occurrence of such conditions in the performing structures, determine the probability of occurrence of scouring and its accurate level, and also we can accurately determine the probability of creation of crack in the downstream bottom slab, or the phase related to separation of particles from the bed, which are of high importance in designing plunge pool. In this study (Balarood dam), by providing conditions of measuring dynamic pressures on the bottom due to impact of the exiting jet from the goblet-shaped projectile, we have attempted to extract some data in various conditions of impact in terms of exit jet discharge and the shallow depth. The obtained results indicate that the downstream plunge pool, would be effective time goblet-shaped projectiles in which the ratio of pool's water depth to thickness of the colliding jet (Y/Bj) is bigger than 3.