The Optimal Cross-section Design of the Trapezoid-V Shaped Drainage Canal of Viscous Debris Flow

Debris flow drainage canal is one of the most widely used engineering measures to prevent and manage debris flow hazards. The shape and the sizes of the cross-section are important parameters when design debris flow drainage canal. Therefore, how to design the appropriate shape and sizes of the cross-section so that the drainage canal can have the optimal drainage capacity is very important and few researched at home and abroad. This study was conducted to analyze the hydraulic condition of a Trapezoid-V shaped drainage canal and optimize its cross-section. By assuming characteristic sizes of the cross-section, the paper deduced the configuration parameter of the cross-section of a Trapezoid-V shaped debris flow drainage canal. By theory analysis, it indicates that the optimal configuration parameter is only related to the side slope coefficient and the bottom transverse slope coefficient. For this study, the Heishui Gully, a first-order tributary of the lower Jinsha River, was used as an example to design the optimal cross-section of the drainage canal of debris flow.