Characterization of seismic sources using sequential spatial clustering and fractal dimension

Abstract

Despite years of research, unexpected seismic events in mines continue to cause damage and loss to people, equipment, infrastructure, and reserves. This research uses novel approaches to characterize the locations, times, and intensity of seismic events for four known seismic sources. The seismic source case studies are the development of a ramp, the abutments around a zone of stopes, a failing stope pillar, and a shear zone adjacent to an orebody. Each seismic source is characterized by sequential spatial clustering, and the fractal dimension of the seismic source parameters of location, time and intensity. The novel application of sequential spatial clustering preserves the sequence of events within a cluster. The method can be used at any point in time which means as a rock mass changes the seismic response is expressed and identified very early on. Once identified, it allows the opportunity for investigation and decision making to take place as the rock mass changes in an unexpected manner. The application of fractal dimension to seismic source parameters revealed that the fractal nature of a parameter is not infinite but exists within a range. The fractal range reflects the character of a seismic source. If some events occur outside the fractal range they also provide important information about the history of the seismic source that occur less often than the fractal range but are still possible. This research has expanded the knowledge of when, where, and how intense seismic events can be expected for four seismic sources using a new sequential spatial clustering method and fractal dimension characterization.