Flood discharge atomized rain is the non-neglectable activator for rock mass landslide

which besides the rainfall. At first

through the relation between seepage characters of fracture rock mass and stress

elastic-plastic constitutive equation of fracture rock mass and control equation of seepage field

the equation continue media model of seepage and stress field coupling is established. Secondly

a 3-D finite element program of saturated-unsaturated seepage and stress coupling under atomized rain programmed

the two-field coupling is solved by iteration method. Finally

taking a typical project for example

the geological model is established according to the earth’s surface information

excavation information

terrane borderline information

drainage hole and purdah information; the rock mass deformation

stress and plastic area are analyzed in detail by coupling computation

the analysis shows that the slope stability has closely related with the change of saturated-unsaturated seepage field of rock mass system; the seepage field of rock mass system must be considered when estimating slope stability. The result can provide some scientific foundation for project slope stability estimation.