Abstract: The rainfall infiltration will affect the soil stability, which may eventually lead to terraced farm field landslides and the crop yield reduction. Therefore, it is of high social and economic benefits to study the stability of the terraced farm field slopes under the rainfall infiltration. In this study, based on the random field theory, the finite element limit analysis combined with the strength reduction method is used to analyze the reliability of the terraced farm field stability under the rainfall by evaluating the terraced farm field factor of safety, the failure probability, and the destabilization risk. The results show that the traditional qualitative analysis does use a unique factor of safety to evaluate the stability of slopes, but the same factor of safety may correspond to multiple slip surface forms and landslide volumes, which is easy to overestimate the safety reserve of these slopes. Based on the random field theory, the slope stability is evaluated comprehensively by combining the slope factor of safety, the failure probability and the failure risk, which can more reasonably assess the risk of terraced farm field slope instability.

Key words: Rainfall Infiltration, Slope Stability, Random Field, Terraced Farm Field Slopes