Research on the Hazard Assessment for Highway Slope Dangerous Rock Masses

With the rapid development of the national economy, a large number of projects such as highways, railways, and hydropower stations have been constructed in the mid-western mountainous areas of China. The instability and rockfall of dangerous rock masses in engineering areas have become a serious and frequently occurring geological hazard. In order to reduce economic losses caused by the collapse of dangerous rock masses and ensure the safety of people's lives and property, research on the failure and disaster mechanism of dangerous rock masses, the kinematic characteristics during the collapse process, and risk management has become a major technical challenge that urgently needs to be addressed in the field of disaster prevention and mitigation. Taking the sudden falling-type collapse of dangerous rock masses on the steep cliff at Section K35+850 of the Lichuan-Wanzhou Expressway in western Hubei Province as the engineering background, this study employed unmanned aerial vehicle (UAV) photogrammetry technology to acquire the 3D point cloud and 3D realistic model of the dangerous rock masses on the subgrade steep cliff, and extracted the geometric characteristics of the residual dangerous rock masses. Based on the structural plane interpretation technology using the 3D model, the occurrence information of the dangerous rock masses and their controlling structural planes was obtained. Numerical simulations were performed using Rocfall and 3DEC software to deduce the movement trajectories and influence ranges of the residual dangerous rock masses, and a risk assessment was carried out by segmenting the falling area of the dangerous rock masses. Finally, reasonable disposal measures and technical suggestions for the risk management of the dangerous rock masses were put forward.