Under plane deformation conditions,a large number of subgrains containing many dislocations forms,and high angle grain boundaries occur due to geometric severe plastic deformation.

For qualitative analysis of deep drawing for rectangular box, quantitative analysis solution of stress in flange has been obtained from the deformation characteristics of rectangular box during deep drawing, on the basis of hypothesis that deformation law of shear stress zero-line is the same as axisymmetric workpieces formed by four corners for deep drawing.

With the deformation characteristics of rectangular box in deep drawing, analytical solution of stress on deform ation area has been obtained on the basis of the hypothesis that deformation law of shear stress zero-line is the same as the corresponding axisymmetric workpie ces, then the fracture limit is predicted.

On the basis of analysing monitored information of boreholes of seven hydro-engineerings and twenty-seven rock-slopes and landslides obtained by borehole inclinometers,the forms of deep deformation curves may be at least divided into four kinds of curves in category,i.

The study on deep-seated deformation of rock slopes can play important role in prevention and mitigation of geo-hazards and construction of infrastructures in mountainous areas.

The prediction model for deformation of deep excavation is suggested according to the Grey System theory.