Effects of the Two-phase Compositions on the Solid-phase Velocity of Debris Flows
The velocity of solid-phase particles of debris flows is a key issue for its kinematics and prevention measures.Flume model tests and particle image velocimetry were conducted to get the solid-phase velocity of debris flow.Effects of slurry viscosity,volume con-centrations and particle sizes on the solid-phase velocity characteristics were accordingly analyzed by adopting two-phase debris flow mod-el.The results show that the high-concentrated-particle debris flow head gets weak with the increase of slurry viscosity and volume con-centration.The relative motion between solid and liquid phase decreases with the increase of slurry viscosity,and it vanishes when the volume concentration is big and the particles are small.The solid-phase velocity of debris flow has a positive correlation with the slurry viscosity and volume concentration,and has a negative correlation with the particle size.Two-phase composition of debris flows affect the force of friction and/or collision between solid-phase particles,and the viscous resistance force,the viscous drag force and the virtual mass force acting on particles,which are induced by slurry.The influence of these forces on the solid-phase velocity needs further study.