Seminar report of piano key weir for dam construction .

Abstract

Free flow spillways are gated simple and secure, but less specific flow of their traditional size requires high spilling nappe depth and thus heavy loss of storage. Free flow flow ("Piano Key Virus") has the ability to increase specific flow in a newly developed form, as four times more on low discharge. At low cost, many existing, as well as new dams, can increase the safety and storage and / or flood control efficiency significantly. Thus, it is very beneficial to increase as much flow as possible. A few tens of existing spillways have been designed accordingly to the vertical walls on a flat bottom, in which there is a Trepozidal maze layout, which is much higher than the length of spline (often four times). They usually double the typical flow of Oz spillway. The name of the piano-key hero comes from the shape of its plan-shaped look, which looks like a 'piano-key', it is configured as polygon walls, such as providing a longer crest length than conventional Ozzy Spillage.