Structural Stress And Concentration Of Mining-Induced Seismicity

In situ stress on the scale of a tunnel or mine may be distorted by geologic structures. The resulting variations in in situ stress have a direct bearing on the potential for mining-induced seismicity. New evidence collected from the Lucky Friday mine by US Bureau of Mines researchers, as well as a review of previous case studies, demonstrated that in situ stress variations affect the [spatial] distribution of mining-induced seismicity. Although overcore stress measurements have been useful in these studies. they are too expensive and, depending, on conditions, may be too difficult to collect. However, information on borehole and raise breakouts: deformation of mine openings: and patterns of seismicity, ground-control problems and rock-burst damage can be used to build a stress database. In conjunction with maps of mine structure and geology and models of rockmass behavior, this database can then be used to build a map of in situ stress variations. Such a map could provide a means of anticipating patterns of mining-induced seismicity and. Thus, could be the basis for planning appropriate measures to ameliorate rock-burst hazards.