Study on Seismic Dynamic Response Characteristics of High-Steep Rock Slopes Based on Wavelet Packet Analysis

To investigate the dynamic response characteristics and deformation failure mechanisms of high-steep rock slopes under seismic loading, this study selected counter-tilted high-steep rock slopes in the Jinsha River Basin of the Sichuan-Tibet Traffic Corridor as the research object. Based on clarifying their slope structural characteristics and typical rock mass strength parameters, a shaking table physical model with a geometric similarity ratio of 1:100 was designed and constructed. Five types of seismic waves—Wenchuan wave, 2Hz sinusoidal wave, 4Hz sinusoidal wave, 8Hz sinusoidal wave, and 12Hz sinusoidal wave—were simulated on the shaking table to measure dynamic response data under seismic excitation. Wavelet packet analysis was employed to extract and analyze the time-frequency characteristics of slope responses, identifying the influence of energy distribution across different frequency bands on slope stability and failure mechanisms. The results revealed that the seismic-induced failure of high-steep counter-tilted rock slopes progresses through three distinct phases: (1) interlayer dislocation and rock block toppling at the slope shoulder and crest, (2) formation of shear sliding surfaces, and (3) large-scale shallow failure on the slope surface. The low-frequency energy components (E1 and E2) dominated the seismic waves and exhibited a reciprocal variation pattern with increasing elevation, while high-frequency components primarily governed localized slope damage. Notably, low-frequency energy significantly influenced global slope stability, whereas high-frequency energy drove localized fracturing. This study provides critical experimental evidence and theoretical support for seismic-resistant design and hazard early warning systems for high-steep rock slopes.