Evaluation method of local failure characteristics for joint based on white light scanning technology

Abstract Joint is one of the important factors affecting the stability of engineering rock mass. To quantitatively analyze the local failure characteristics of joint, the point cloud data of its morphology before and after shear were obtained by 3D white light scanning technology. Firstly, the problem of cloud surface skew of point cloud data was solved by constructing rotation matrix and translation matrix based on the principle of least square method, and the datum plane of joint was determined. Then, the datum plane of the joint before and after shear was adjusted to be consistent based on the point cloud data of the marked points and the undamaged area of the joint, and the point cloud data with equal spacing were obtained by one-dimensional or two-dimensional interpolation algorithm. Finally, a 3D description method of joint local Morphological characteristics is proposed. The proposed method can determine the scope of surface failure of joint, quantitatively analyze the locality of its failure characteristics, and provide data support for distinguishing the types of shear failure and further research on shear mechanism.