A method of tunnel critical rock identification and stability analysis based on a laser point cloud

The role of 3D laser scanning technology in the identification of critical rock in engineering is becoming increasingly important. In order to improve the recognition efficiency and accuracy of this identification, it is particularly significant to propose an analytical method for matching critical rock with point cloud technology. Based on the research foundation of 3D laser scanning technology in the field of rock mass structural surface identification, this paper proposes a critical rock identification and stability analysis method based on laser point cloud technology. First, a calculation method for a closed critical rock body is proposed. Second, block theory and point cloud technology are combined. Then, by utilizing the high-density features of the point cloud, the vector analysis method of the traditional critical rock is converted into the space coordinates of the 3D point cloud, and the internal coordinate system of the 3D laser scanning system is directly used to extract the X, Y, and Z coordinate values of the corner points of the critical rock. Next, these coordinates are spatially compared and analyzed, and the key critical rock determination and its corresponding instability method are identified. Finally, the movable identification and stability analysis of the critical rock on the geometric scale is attained. This paper mainly summarizes the identification of closed critical rock bodies, the movable identification of key critical rock, and the determination methods of three types of critical rock instability modes as follows: falling type, single-sided sliding type, and double-sided sliding type. The method of the visual analysis process is implemented using C++ and OpenGL language programming. Eventually, the method is applied to practical engineering, and good results are obtained, which demonstrates the effectiveness of the method and makes it of great significance for future engineering applications.