Abstract:Columnar dangerous rock mass is an important type of dangerous rock mass in slope stabili ty analysis. Its instability and failure often results in large-scale, high-energy rockfall disasters with de structive power. These events are characterized by their prevalence, sudden occurrence, and high fre quency, making them one of the main geological hazards that restrict the construction and develop ment of mountainous areas. Discontinuous deformation analysis (DDA), a numerical method based on the mechanics of discontinuous media, provides a comprehensive kinematic theory and reliable block contact handling schemes, making it highly suitable for simulating the instability, failure, and move ment processes of jointed rock mass systems. This study used the three-dimensional (3D) DDA meth od to investigate the instability failure mechanisms and post-failure movement of columnar dangerous rock mass. An experimental setup based on binocular stereovision principles was developed to study the instability and failure of dangerous rock mass. Laboratory experiments on columnar block systems were conducted, validating the accuracy of the 3D DDA method in analyzing the instability movement of columnar dangerous rock mass. Using the columnar dangerous rock mass of Wangxia slope as an ex ample, a 3D DDA numerical model for the slope and dangerous rock mass was established. The entire instability movement process, kinetic energy, and displacement evolution characteristics of the colum nar dangerous rock mass were analyzed. The movement characteristics of the block system and mecha nisms of the collapse and rockfall-induced disasters were discussed. The results showed that the colum nar dangerous rock mass became unstable through sliding, and it directly collided with the highway along its path during its movement, causing rockfall geological disasters. This movement exhibited ki nematic characteristics such as high speed and high energy.
