To counter the shortcomings existing in limit-equibrium method(LEM),the stability analysismethod considering the deformation of the slide plane in wedge is presented in this paper,the results ofstability analvsis coincldes with test values,While the safty factor calculated in LEM is a bit too great.

In this paper,some main shortcomings when traditional equilibrium method (LEd)is to be used on rock slope with single slide plane are pointed out,and then a new stability analysis method on the slope in slide plane deformation is studied.

To improve the performance of the controller, a design scheme of variable sliding-surface is proposed, and Lyapunov stability theorem is used to prove the stability of the system.