Abstract: In order to quantify the influence of horizontal and vertical seismic actions on the slope stability, a typical slope is taken as an example. The finite element strength reduction method was used to analyze the influence of horizontal seismic actions only, vertical seismic actions only, and combined horizontal and vertical seismic actions on the slope stability. The seismic actions in different seismic magnitude areas were also considered in combination with the relevant seismic codes of China. The results show that it is necessary to consider the horizontal seismic action in the area of earthquake magnitude 7 degree and above, and it is necessary to consider the vertical seismic action in the area of magnitude 9 degree.

Key words: Horizontal Seismic Action, Vertical Seismic Action, Finite Element Strength Reduction Method, Seismic Magnitude, PseudoStatic Method