Slope engineering is a dynamic

fuzzy

open and complicated system

and the factors which control and affect slope stability are random and fuzzy variables. It is difficult to evaluate the stability of complicated slopes by traditional analysis method. Based on the basic theory of fuzzy probability

the fuzzy probability model of stability evaluation of depth cutting slope is proposed. Some main control factors of rock slope

such as slope rock quality coefficient

slope structure coefficient

slope height coefficient

slope angle coefficient and engineering factor effect coefficient etc. are selected. At the same time

the slope stability grades are classified as the very instable

instable

basically stable

stable and very stable in the prediction model. 20 typical slope engineerings are performed by this model. The prediction results agree well with the practical records. It indicates that the fuzzy probability model is reasonable and effective to evaluate the stability of depth cutting slope in rock mass

and provides scientific basis for reducing and preventing of the instability of rock slope.