Rock mechanics study of shaft stability and pillar mining, Homestake Mine, Lead, SD (in three parts) 3. Geomechanical monitoring and modeling using UTAH3.
Pariseau-WG; Johnson-JC; McDonald-MM; Poad-ME
Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9618, 1996 Jan; :1-29
Due to the importance of shafts to mine safety, the feasibility of conducting a three dimensional, finite element analysis was investigated. Experience gained from three dimensional analyses of undercut and fill stopping at the Lucky Friday Mine and of vertical crater retreat mining at the Homestake Mine were useful in addressing the issues associated with shaft pillar mining. Borehole extensometers and other instruments were installed to provide data for model verification and to monitor shaft displacement. Results of a calibrated two dimensional model (UTAH2) confirmed the premining stability evaluation. After mining began, however, concern developed because of cracks and other regions of ground motion that appeared at considerable distances from the areas of active pillar mining. The computer modeling program UTAH3 was initiated for an intense three dimensional modeling effort. The results of that analysis indicated that the observed defects were within expectations and that the shaft would remain safe. Three dimensional analyses of alternate pillar mining scenarios indicated that more of the shaft pillar ore reserve could be recovered than previously thought on the basis of two dimensional analyses. The study demonstrated that through an integrated program of laboratory testing, stress analysis, and mine measurements, the three dimensional, finite element analysis is an engineering tool for mine stability analyses and design where the cost is justified by the importance of the mining objective, in this case, the safe and profitable recovery of ore in shaft pillars.
Mining-industry; Ground-stability; Ground-control; Geology; Rock-bursts; Rock-mechanics; Room-and-pillar-mining; Underground-mining; Physical-properties; Safety-research; Computer-models; Safety-engineering; Physical-stress; Structural-analysis
Report of Investigations
NTIS Accession No.
Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9618