Rock Mechanics Investigations at the Lucky Friday Mine. Part 3. Calibration and Validation of a Stope-Scale Finite-Element Model.

摘要

The U.S. Bureau of Mines has been conducting a series of rock mechanics investigations at the Lucky Friday Mine in the Coeur d'Alene Mining District of northern Idaho. The present study uses rock deformation measurements to validate and calibrate a geomechanical model of the experimental Lucky Friday underhand longwall (LFUL) stope on the 5100 level of the Lucky Friday Mine, Mullan, ID. The calibrated three-dimensional, finite-element model and measurements of rock mass displacement show a correlation of 0.795. The calibration reduces rock mass modulus to 14 to 17 pct of laboratory values and rock mass strength (with an energy rule) to 37 to 41 pct of laboratory values. The model suggested that stress-related ground control problems would be encountered west of the stope where the vein makes a right-angle turn and then splits.