Abstract: A large number of gently inclined landslides occurred after heavy rainfall in Nanjing and Zhenjiang area. The temporary confined water was formed by the rise of water level in the slopes after rainfall. Landslide deformations showed uplift in the leading edge and tension crack in the trailing edge of the slope. According to the in-situ geological survey of Shilong Road landslide in Jiangning, Nanjing, the stratigraphic structure of the landslide is characterized by the dualistic geological structure that the upper part is fine and the lower part is coarse. This study chose Shilong Road landslide as an example to analyze its failure characteristics. Based on the basic principles of simple confined water distribution model and simply supported beam model, this paper attempted to analyze the mechanical mechanism of uplift and failure in aquiclude of front section of the slope under the action of temporary confined water. Aiming at the uplift characteristics of leading edge of the landslide, a one-dimensional steady flow model was constructed to analyse the distribution characteristics of confined water in the permeable layer of front slope. The simply supported beam model was introduced to analyse the influence of confined water uplift pressure on the deformation and stability, and the law of cracks development in aquiclude. The criterion of failure after uplift of aquiclude was determined, and the influence of uplifted pressure head at the foot of slope and thickness of aquiclude on the failure characteristics of aquiclude was analysed in detail. The results show that confined water head in the permeable layer is triangular distribution. The deepest crack in aquiclude develops at the maximum bending moment of uplift pressure on simply supported beam model. The maximum damage area of aquiclude is positively correlated with the uplift pressure head at the foot of slope and negatively correlated with the thickness of aquiclude. The critical uplift pressure head and the critical thickness of aquiclude are approximately linear when
the aquiclude occurs uplift-tension failure.

Key words: permeable layer, temporary confined water, simply supported beam model, uplift-tension failure, critical failure conditions