Abstract:Bingham model can describe the slow movement of natural slopes. Nonlinear viscosity is taken into account in Bingham constitutive equation due to the existing of pore water pressure. Then an explicit expression can be derived by simplifying the viscosity and root-reinforcement functions. The numerical methods can also be used in other complicated boundary problems. The proposed formula based on Bingham model is applied to describe one typical creeping soil slope. The concept of shear layer can be easily emerged by the formula with fewer model parameters. The reinforcement of root relies on the affecting depth and time.