Sensitivity Analysis of Seismic Response in Soft-Hard-Interlayer Slopes

In recent years, seismic disasters have captured worldwide attention and garnered extensive research efforts. A series of significant earthquake events, such as those in Haiti, Nepal, and Italy, have resulted in substantial loss of life and property damage. Of particular importance is the impact of earthquakes on slope stability, triggering slope loosening, landslides, and collapses, posing significant threats to both human lives and assets. Therefore, studying the seismic-induced dynamic response of slopes is of utmost importance. This study, employing the Flac3D finite difference method software, investigates the dynamic stability of soft-hard-interlayer slopes formed during the construction of mountainous highways under seismic influences. The study reveals that both acceleration and displacement responses exhibit significant elevation amplification effects. However, due to the higher compressive strength of hard soil layers, the restraining effect on soft soil layers is relatively weak, manifesting in a decreasing trend in certain specific locations. Consequently, acceleration response is lower in hard soil layers but higher in soft soil layers. The analysis of displacement and stress further reveals the influence of soil properties on slope response, with hard soil layers bearing greater stress within the slope. Additionally, the analysis of displacement and stress highlights that the displacement response in soft soil layers is more prominent compared to hard soil layers, and stress concentration phenomena are likely to occur at the toe of the slope. This study provides valuable reference and guidance for slope engineering, ensuring the safety of human lives and property.