Abstract： U n loading non linear rock m ass m echan ics, one new concep t in geo techn ics, is pu t fo rw ard by the au tho r in th is paper, and w ho se m ain research ing con ten t s are dis2 cu ssed in the paper. The resu lt s iden t ify that there is in t rin sically dist inct ion betw een un2 loading non linear rock m ass m echan ics and no rm al loading one. The excavat ion of rock slope is under the un loading condit ion s, and the loading condit ion s as befo re can no t m an i2 fest the essen t ial featu res of the slope. A cco rding to cases analysis abou t bo th natu ral and art if icial cu t rock slopes in un loading non linear rock m ass m echan ics, it is discovered that the research ing resu lt s in th is m ethod are w ell acco rdan t w ith actual featu res of rock slopes.
