A New Method for Three-Dimensional Fracture Network Modelling for Trace Data Collected in a Large Sampling Window

This study presents a new three-dimensional (3D) network modelling method for fractures collected in a large sampling window, in which the determination of fracture disc diameter is the critical step. To derive the diameter, the disc radius of the fractures of the investigated exposed rock surface is initially obtained based on the collected trace lengths. Then, the disc radius of the fractures in 3D space is deduced. The determination of the density and orientation of fractures is also included in the study. Subsequently, the 3D fracture networks for each fracture set are generated based on the derived diameter, density and orientation. To verify the rationality of the method, the rock masses downstream of the sluice gate of Datengxia hydropower station are selected as study objects, and a plane with identical orientation to the exposed rock surface is intersected by the network, thereby obtaining the fracture traces in the plane. The statistical characteristics of fracture traces in the plane and those of the exposed rock surface are highly similar. Thus, the proposed method is feasible.