Analysis of four rockbursts in the Lucky Friday Mine, Mullan, Idaho, USA.
Jenkins FM; Williams TJ; Wideman CJ
Int'l Deep Mng Congress S Afr Inst Min and Metall 1990; :1201- 1212
The U.S. Bureau of Mines is studying the source mechanisms of large rockbursts that are threatening future mining operations in the deep mines of the Coeur d'Alene Mining District of northern Idaho. Understanding source mechanisms and the geologic conditions necessary for their occurrence are considered keys to development of cost-effective ground support systems, mining methods, and preconditioning technques that would mitigate rockburst hazards. Source mechanism information was obtained with a macroseismic monitoring system installed at the Lucky Friday Mine, near Mullan, Idaho, in April 1989. The system uses five triaxial geophones to monitor first motions of bursts in the 0.5 to 2.5 Richter magnitude range. Geophone output was continually digitized by a data acquisition system, but data were stored only when the system was triggered by a large burst. Standard earthquake analysis software was then used to determine source mechanism parameters from the digitized waveforms. Data recorded from four rockbursts that occurred between July 6 and November 6, 1989, were used to evaluate system performance.
Mining-industry; Region-10; Rock-bursts; Geology; Ground-control; Ground-stability; Monitoring-systems; Environmental-control; Environmental-hazards
OP; Conference/Symposia Proceedings
Int'l Deep Mng Congress S Afr Inst Min and Metall