Quantitative study on the classification of unloading zones of high slopes

Unload and unloading zones of high rock slope are familiar phenomenon in southwest area of China,which influence stability of rock slope and other rock-engineering problem.On the basis of analyzing the actual way of classification of unloading zones,the author puts forward a divisiory way of adopting joint rate,opening joint rate and summation of joint width as quantitative indexes according to formation mechanism and geological exhibition of unloading zones.After large numbers of locale measurement of joints,analytical result indicates that there is a good corresponding connection between the three indexes and unloading degree,and it is feasible to regard the three indexes as quantitative standard of classification of unloading zone.Furthermore,combining to qualitative geological characteristics of unloading zones,the author presents material project for actual engineering.