Abstract: A reliability analysis method for the Toudaohe No. II landslide is presented in this paper, which considers the fuzzy randomness of rock and soil parameters and the transition interval between the fuzzy randomness of rock and soil parameters and the fuzzy slope, in response to the failure to consider the Ambiguity of the shear strength parameters in the stability analysis of the Toudaohe No. II landslide. The method converts the random values of the soil sample tested mechanical parameters into the fuzzy random variables. Based on the fuzzy random variables and fuzzy transition intervals, a fuzzy random limit state equation is established. Different geotechnical parameters λ as well as the upper and lower limits and their corresponding limits state equations are also determined. A formula for calculating the reliability of the Toudaohe No. II landslide that is only related to geotechnical parameter variables is derived. By using the Geostudio software, the fuzzy random reliability of the Toudaohe No. II landslide is simulated and estimated. Finally, the reliability estimated by the traditional Monte Carlo simulation method is presented in the paper. It is found that, when the failure probability obtained by using the traditional reliability estimating methods is 8.04%, and considering the ambiguity of shear strength parameters, the landslide failure probability is 11.99%. This indicates that the failure probability of the Toudaohe No. II landslide considering the fuzziness and randomness of geotechnical parameters has increased.

Key words: Toudaohe II landslide, fuzzy reliability, stability evaluation