A Sensitivity Analysis of Piano Key Weir Overhang Crest Length

Abstract

  In the scope of dam rehabilitation to manage floods increase or to increase storage, the Piano Key Weir is a good solution for concrete dams. The efficiency of Piano Key Weirs is now well demonstrated through various experimental studies. Until now most of the Piano Key Weir prototypes close to the Piano Key Weir Type A using symmetrical up- and downstream overhangs for structural reasons. The position of the overhangs influences the inlet and outlet key slopes and cross section as well as the side crest length influenced by these slopes and cross sections. On this paper, the influence of these main parameters has been studied on several models considering variation of the overhang lengths.