Abstract:

The number, attitude and developmental state of rock mass discontinuity of tunnel are important indexes to evaluate permeability and stability of tunnel. Laser point cloud data and geometry information of rock mass discontinuity around the tunnel can be obtained quickly using the three dimensional measurement technology. The reconstruction technology of triangular mesh of laser point cloud was proposed based on the projection of cylinder method and Delaunay growth algorithm, the attitude of single triangular mesh surface was calculated using the normal vector of the plane equation of the constructed triangular mesh, and fuzzy cluster classification of the attitude of the discontinuity of tunnel was carried out with the application of FKM (Fuzzy K-Mean) cluster method. The different groups of the attitude in advantage can obtained quickly using this method, and the spatial display of the result of the classification can be conducted with different colors. Finally, the study of the attitude in advantage of the discontinuity of some tunnel was carried out using the software FSS developed independently, the results of the study show that: 1)The constructing mesh with point cloud method based on the projection of cylinder method and Delaunay growth algorithm is particularly suitable for tunnel project, the speed of construction of mesh is fast, the efficiency is high, and the topology difference of the reconstructed surface of triangular mesh and the surface of sampling rock mass is minimum. 2)The result of cluster classification of the structure surface of rock mass of tunnel with the method of FKM fuzzy cluster is reliable, reasonable, and has strong commonality and extension.

Key words: 3-D laser scanning, rock mass discontinuity, laser point cloud, FKM, fuzzy clustering