Mapping the Excavation Disturbed Zone Around the Mine-by Tunnel Using Induced Seismicity and Velocity Imaging

Abstract

The potential for mapping the EDZ using a combination of induced seismicity and velocity imaging is presented using the Mine-by tunnel as a specific case study. Concentrations of induced seismic events have been used to locate regions of induced fracturing, as well as changes in location with time to monitor progressive failure. Estimates of the size, magnitude and stress release during the events can also be used to assess the nature of the seismic deformation. In particular, moment tensor inversions are employed to examine the micro-mechanics of the seismic deformation. Images of the rock mass velocity structure around the tunnel are also used with the seismicity to investigate the rock mass response to excavation-induced stress changes. The Mine-by experiment thereby serves as a comprehensive example of applying seismological techniques in EDZ investigations.