COMPARISON OF ENERGY DISSIPATOR BETWEEN ROUGHNESS SLOPE WITH STACKED BOULDERS AND ABRUPT DROP IN LOW DROPS

Abstract

 The authors proposed the installation of roughness slope with stacked boulders for the protection of riverbed. This paper presents a comparison of energy dissipator between roughness slope with stacked boulders and abrupt drop. The experimental investigation on the formation below an abrupt drop yields that a hight velocity flow near the bottom continues far doswnstream. Also, the protection region predicted by design manual is short from the location of main flow in the jump. While, the experimental investigation on the installation of roughness slope with stacked boulders yields that the main flow lifts to the water surface in a short distance, because the approaching Froude number can be redused by the shape effect of stacked boulders. Furthermore, the installation of protection concrete blocks below the stacked boulders may support for the bed protection.