Abstract: The rainfall affects the slope stability and is an important inducement of the landslide geological hazards. This paper presents evaluation results of the slope of a project spoil site. The seepage characteristics of the slope under continuous rainfall and rainfall with different intensities are studied using the Geo Studio software SEEP/W module. The limit equilibrium method is used to analyze the slope stability under different rainfall duration through SLOPE/W module. The results show that the pore water pressure in the shallow layer of the slope changes greatly at the beginning of the rainfall, and then quickly tends to be stable. Under the same rainfall duration, the influence of the heavy rain, the rainstorm and the heavy rain on the pore water pressure of the slope gradually weakens. After 7 days of continuous rainfall, the infiltration depths corresponding to the different rainfall intensities are 12.1m, 6.9m and 1.6m respectively. Under the condition of the heavy rain, with the increase of rainfall time, the slope safety factor shows a decreasing trend, from 1.903 in natural state to 1.765, and the safety factor decreases by 8%, but it is still greater than 1.20 specified in the specification under the condition of heavy rain. Therefore, the factor of safety of the waste soil slope meets the code requirements. The research content of this paper will provide a reference for the stability evaluation of the similar slope under the rainfall conditions in the future.

Key words: Slope with Waste Soils, Rainfalls, Stability Analyses, Seepage, Factor of Safety