The displacements and long-term stabilization of the old landslides in Three Gorges Area importantly depend on both the decreasing of strength and time-effect of the mechanical characters of sliding zone soils. In order to set up a basis of the further numerical analysis

the drained triaxial compression tests with the constant stress have been carried out. Based on those tests a shear stress-strain-time function

Mesri creep model

in which a hyperbola is adopted for shear stress-strain behaviour and power function for strain-time behaviour

is given.