Ground Conditions and the May 13, 1994 Rock Burst, Coeur d'Alene Mining District, Northern Idaho

ABSTRACT: Rock bursts continue to be a significant but poorly understood safety hazard faced by miners throughout the Coeur d'Alene Mining District of northern Idaho, Such hazards remain difficult to anticipate, Prediction of individual bursts has proven to be a rare event. Even after a burst, there is often considerable uncertainty over what actually occurred and why. This paper presents results of an in-depth investigation of a rock burst undertaken by NIOSH as part of research aimed at protecting miners from rock burst safety hazards, In this case study, investigators found evidence of unusually intense and rotated stresses in the immediate vicinity of the burst. Moreover, these stress conditions appear to be associated with particular geologic features, Finally, the spatial distribution of stress conditions points to the existence of a strong residual stress system.