Experimental Study of Overflow Regimes on Labyrinth Weirs with Sharp Crest

Abstract

Labyrinth weirs have high discharge performance and high effect as dam spillways, check gates. Though their overflow state often becomes unstable from their thin sectional shape which is inevitable for their zigzag plane shape. This unstable overflow state is generally undesirable for their application to dam spillways, check gates and so on. To avoid or restrain this unstable state on design of labyrinth weirs, we made clear about relations between their shapes and overflow regimes in this study. From the results, it became clear that H/P range of unstable overflow was narrow in shapes of W/P =1.5-2 in spite of change of A/W, L/W (P: Weir height, W: Width of 1 cycle of a labyrinth weir except its elbow, L: Crest length of 1 cycle of a labyrinth weir except its elbow, A: Apex half length of a labyrinth weir).