Effects of topography and geology on the seismic response of a high-steep rock slope based on the time-frequency joint analysis method

To study the influence of the valley topography effect and the geological effect of structural planes on the dynamic response characteristics and failure mechanisms of a steep rock slope, a time-frequency joint analysis method combining time, frequency and time-frequency domains analysis is proposed. Four models were created for dynamic analysis using FLAC3D. According to the time-frequency joint analysis, the dynamic response law of homogeneous high-steep slopes is that the acceleration amplification factor (AAF) varies periodically along the elevation with a certain pattern and is obviously amplified at the slope crest. The existence of structural planes reduces the velocity of wave propagation through rock masses while creating local amplification and attenuation of seismic waves. The valley topography has an amplifying effect on the dynamic response of the slopes but has less influence on the changing laws. Frequency domain analysis shows that the low-frequency and high-frequency components mainly cause overall deformation and local deformation of the slopes, respectively. Moreover, structural planes have a high-frequency filtering effect, and the influence of structural planes on the failure mechanism of slopes is significantly greater than that of valley topography. In addition, the relationship between the local deformation response of anti-dip slopes and the occurrence of landslides is determined. In addition, the dynamic response characteristics of the slope were analysed based on the Hilbert energy, and the ability of the seismic Hilbert energy spectrum to reflect the dynamic deformation characteristics of the slope was identified.