which contains liquid-phase with slurry and solid-phase with coarse grains. The resistance characteristics
which can be divided into internal resistance and external resistance
is a critical factor for the study of kinematic and dynamic of debris-flow.The external resistance caused by interaction between debris-flow and gully-bed and gully-wall depends on the roughness and geometric shape of gully and properties of debris-flow.The debris-flow can be classified into viscosity debris-flow and two-phase debris-flow for understanding their internal resistance characteristics. For the former
the solid-phase and liquid-phase during the motion have no obvious slip velocity
therefore viscosity debris-flow could be identified as a kind of homogeneous mixing fluid and modeled by pseudo-homogenous fluid. However
for the two-phases debris-flow
the solid-phase and liquid-phase have obvious slipvelocity;the stress forces due to solid-liquid interaction
such as viscosity drag force and virtual mass force etc.
plays critical role
and thus the stress due to interactions of solid grains
which comes from granular flow
is a key factor. The Fine contents in liquid-phase slurry has a huge effect on the resistance character of a debris flow and can change the resistance character of liquid-phase slurry
including yield stress and viscosity coefficient. Furthermore
the viscosity coefficient of slurry can have effects on stress due to interaction of solid grains. In this study
a comprehensive resistance model of debris-flow
including internal resistance and external resistance