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Shaft Design in the Coeur d'Alene Mining District, Idaho - Results of in Situ Stress and Physical Property Measurements.
MISSING :39 pages
This Bureau of Mines report describes field investigations conducted in the Coeur d'Alene Mining District of Idaho to obtain data on rock stress and physical properties. The resulting information has been utilized as input to detailed finite-element analyses to establish structural design criteria for deep-vein mine shafts. Test sites ranged in depth from 1,200 to 7,700 feet and are described in detail. The stress data were reduced by least-squares linear regression techniques to enable prediction of vertical and horizontal stresses to 7,500 feet. Ratios between the horizontal stresses as utilized for shaft design varied considerably, and a hydrostatic condition is the exception, based on Bureau measurements. Physical properties also varied widely, due to the complex geologic structure. Analyses of the data in terms of the tectonic history of the area show reasonable correlation. Data from previous rock mechanics investigations from the Coeur d'Alene District were also compiled and presented as part of this report.
IH; Report of Investigations
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division