Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Mining Publication: In Situ Stress Measurements Near the Ross Shaft Pillar, Homestake Mine, South Dakota

Original creation date: January 1993

Image of publication In Situ Stress Measurements Near the Ross Shaft Pillar, Homestake Mine, South Dakota

In situ stresses are important input data for the design of safe, stable stope layouts and extraction sequences. However, it is commonly assumed that normal and shear stress gradients in a stress field are negligible and, consequently, that stresses are uniform throughout the region of analysis. To evaluate these assumptions and to provide input data for an analysis of a shaft pillar mining plan, in situ stresses were measured at the Homestake Mine, Lead, South Dakota, using overcoring on hollow inclusion cells and borehole deformation gauges. These measurements were used with conventional least squares, best fit data reduction schemes. The results showed that normal stresses within the shaft pillar were less than, but comparable to, those estimated from finite-element modeling. Shear stresses were an order of magnitude less than normal stresses and varied considerably from site to site. Possible causes of this variability include effects of scale, elastic moduli, anisotropy, and axial strain. Because of the variability, it is not possible to determine the magnitude of horizontal stress gradients.

Authors: JC Johnson, WG Pariseau, DF Scott, FM Jenkins

Report of Investigations - January 1993

NIOSHTIC2 Number: 10003215

Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9446, 1993 Jan; :1-17