Abstract: Weibull distribution function is employed to describe the survival rate of micro-units of rock slope before and after damage; fatigue damage model and strength reduction FEM are also established to reflect the relationship between survival rate, cumulative damage factor and stability coefficient so as to achieve the staged early warning for mountain road slope in its whole life cycle. Results show that the coefficient of fatigue stability in the whole life cycle of slope would decrease under fatigue life reduction, changing sensitively in the early stage, attenuating slowly in middle stage and dropping rapidly in the later stage. The survival rate of slope declines with the reducing of residual life and safety factor. The early warning could be divided into four stages, namely initial creep, steady development, rapid development, and sliding failure. In the four stages, the stability coefficient, survival rate, and operation life of mountain road are all attenuating along with the development of deformation until slope failure. In addition, the concept of slope durability factor is proposed to evaluate the durability of road slope during its whole life cycle. In the durability design of slope engineering, fatigue-resisting measures should be adjusted continuously to make it in steady state development stage.

Key words: mountain road slope, whole life cycle, survival rate, staged early warning, durability factor