Experimental study on dynamic stress and deformation characteristics of landslide dam materials under rolling dynamic compaction

Abstract

The frequent occurrence of geological disasters has led to a constant production of landslide dam materials worldwide, which exhibit characteristics such as loose structure, high porosity, and wide gradation, limiting their development and utilization. To investigate the dynamic stress and deformation characteristics of landslide dam materials under rolling dynamic pressure, laboratory rolling dynamic compaction (RDC) model tests were conducted to study the effects of towing speed, impact roller mass, and pass count on dynamic stress propagation, surface settlement, and particle displacement. The results indicate that dynamic stress increases with the number of passes, stabilizing after 12 passes, with significant attenuation at depths above 200 mm. Maximum displacement occurs when the smooth arc surface of the impact roller contacts the foundation, with higher towing speeds facilitating energy transfer to deeper layers and heavier impact rollers enhancing surface compaction. Surface settlement analysis indicates that most cumulative settlement occurs within the first seven passes. PIV analysis reveals significant particle movement during RDC, with the most notable displacement occurring at high towing speeds and impact roller masses. Increasing the towing speed effectively enhances the dynamic stress, facilitating energy transfer to deeper layers, although the influence width remains limited. Enhancing the mass of the impact roller promotes energy transfer horizontally on both sides, improving surface reinforcement, although the depth of influence is similarly restricted. The study concludes that optimizing towing speeds and impact roller masses is crucial for effective compaction and reinforcement, providing a theoretical basis for the design of RDC for landslide dam foundations.