Whyatt-JK; White-BG; Johnson-JC
Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9619, 1995 Dec; :1-69
Because of a longstanding and continuing rock burst hazard, a large database of information on rock properties in the Coeur d'Alene district was examined and estimates of rock deformation and strength properties were developed for three mechanically distinct rock types based on relative proportions of sericite and quartzite. Test results have confirmed a trend toward softer, weaker, and more anisotropic rock with increasing sericite content. This effect appears strongest for elastic modulus and weakest for strength. The trend is most evident when analysis is confined to test results from a particular mine, or confined to a particular portion of a mine. This finding suggests that an additional mine specific factor is active in addition to relative sericite quartz content. The available test data allowed estimation of rock mass and discontinuity of mechanical properties on the scale of stratigraphic units 1 to 60 meters thick, which are thicknesses relevant to geomechanical analyses of mine structures. Stratigraphy, isotropic properties, anisotropic properties, triaxial tests, in-situ tests (modulus measurements, rock mass classification, displacement measurements, closure measurements, seismic studies), and rock mass properties (elastic and strength properties) were discussed.
Mining-industry; Underground-mining; Physical-properties; Safety-research; Mechanical-properties-testing; Rock-falls; Occupational-hazards
Report of Investigations
NTIS Accession No.
Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9619