Study on dynamic response characteristics of compacted loss slope under freeze-thaw cycles and earthquake loads

The understanding of the dynamic behavior characteristics and mechanisms of seismic landslides in seasonal frozen soil areas following severe freeze-thaw damage is currently limited. Taking a compacted loess slope in Lanzhou National New Area of China as the prototype, freeze-thaw cycle tests and large-scale shaking table tests were conducted, and the dynamic responses of freeze-thaw slope and non-freeze-thaw slope under different amplitudes, directions, and intensities of seismic waves were compared and analyzed. The results indicate that the acceleration responses of compacted loess slopes increase with the increase of the slope height and the value of the slope shoulder is the largest. The acceleration responses also increase with higher seismic intensity. On the other hand, earth pressure responses decrease as the slope height increases, but initially increase with higher seismic strength before eventually decreasing prior to slope failure. Comparatively, the acceleration responses of the freeze-thaw slope are stronger than those of the non-freeze-thaw slope, while the earth pressure responses are smaller, particularly in frost-heaving zones The compacted loess slope demonstrates good stability under seismic waves. However, the loosed and wetted surface after freeze-thaw cycles may experience abrupt shear slip during high-intensity seismic waves. These findings hold significance for stability analysis and reinforcement strategies for engineering slopes in the Loess Plateau with seasonal freezing and thawing.