Spatial Topology Identification of Three-Dimensional Complex Block System of Rock Masses

Abstract

Identification of three-dimensional rock blocks of rock masses is a key technique in rock mechanics and rock engineering. The boundary representation (BR) approach could identify generally shaped blocks, but it is not easily understood by practicing engineers as a result of its combinatorial topology theory. In this paper, a novel spatial topology identification algorithm of the three-dimensional complex block system of the rock masses is proposed. In this algorithm, first, three-dimensional joint networks are simulated using the geological statistical results. Second, the basic data structure of a complex block including the vertex, oriented edge, oriented loop, oriented face, and oriented body is defined. Last, four key techniques, including integrations of line segments, topology analysis of the oriented loops, forming the oriented faces, and topological identification of the rock blocks, are detailed. Based on the cutting algorithm, a program named Rock Block Cutting (RBC) was developed, and the simulation results of serval analytical and classical examples using RBC prove the correctness of the program. Applications of the RBC program in both the slope and cavern examples show that this spatial topology identification algorithm can efficiently calculate the convex rock blocks, concave rock blocks, and band the complex rock blocks with multiply connected characteristics, which provides the geometric model for the key block analysis and the stability calculation of the discrete block system.