Probabilistic Analysis of Progressive Block Failures

ABSTRACT: In order to simplify the analysis of complex key block problems, a matrix approach can be employed to analyze the stability of individual points in a rock mass in the vicinity of an underground excavation. This technique involves a three-dimensional grid of connected, discrete nodal points representing the region around the excavation. The grid is assembled with standard finite element procedures, employing an eight-noded cubic element with 28 connection bars. This approach is an effective way to relax some of the restrictive assumptions of the traditional key block theory. Because of the ease with which this .approach can handle the probabilistic analysis of progressive block failures, it may be employed in the development of block caving models. This will facilitate the efficient solution of realistic problems involving complex excavations and joint structures with a general three-dimensional and point specific analysis.