Based on the simplified Bishop method

formulas for calculating slope seismic stability are derived

which include the pseudo-static method (PSM)

classical pseudo-dynamic method (PDM) and modified pseudo-dynamic method (MPDM). Among these

MPDM treats soil as Kelvin-Voigt material

considering its viscoelastic and amplification characteristics. MPDM is then applied to slope conditions. Subsequently

Morlet wavelet analysis is used to determine the spectral distribution characteristics of seismic waves

with the El Centro wave as the research object. A method for evaluating the seismic stability of slopes is proposed

taking into account the time-frequency characteristics of ground motion by identifying the predominant frequency at the moment of peak ground acceleration (PGA). The effectiveness of this method is validated through illustrative examples. The results show that slope seismic stability can be assessed rapidly and accurately using the pseudo-dynamic method

which requires fewer parameters and provides clear interpretations

closely resembling the results of the time-history analysis method. These research findings establish a theoretical basis for the seismic risk assessment of slopes

the analysis and prediction of the scope of seismic landslide disasters and earthquake emergency response.