An experimental study of dilute debris flow characteristics in a drainage channel with an energy dissipation structure

Abstract

An experimental study was performed to determine the characteristics of a dilute debris flow in a drainage channel with an energy dissipation structure and a channel slope i of 15%. Flow pattern, debris flow depth, and velocity downstream of the energy dissipation structure were investigated along with the energy dissipation characteristics. Dilute debris flow velocity and depth were measured, analyzed, and subsequently used to characterize the dilute debris flow. The flow pattern in the drainage channel indicated that the dilute debris flow was highly turbulent and that flow depth initially increased. However, this increase was followed by a noticeable decrease after passing through the energy dissipation structure. The experimental results also indicated that the debris flow velocity gradually decreased as the length of the energy dissipation structure increased, whereas flow depth gradually increased with increasing length of the energy dissipation structure. Velocity characteristics and depths of the dilute debris flow downstream of the energy dissipation structure were also affected to some extent by variations in the width of the energy dissipation structure. The energy dissipation ratio gradually increased with increasing length and width of the energy dissipation structure for i=15%, and the maximum energy dissipation ratio was approximately 58.69%. These experimental results provide a theoretical foundation for optimal design of drainage channels with energy dissipation structures.