00000nam 2200000za 4500 9.840838 CaOODSP 20221107151936 cr ||||||||||| 170801s1972 onc ob f000 0 eng d CaOODSP eng n-cn--- M38-8/109E-PDF M38-8/109 Gray, W. M. Analysis of accuracy in the determination of the ground-stress tensor by means of borehole devices [electronic resource] / W.M. Gray and N.A. Toews, Mining Research Centre. Ottawa : Information Canada, 1972. p. 45-78 Reprint series ; RS 109 Cover title. "Reprinted from Proceedings of the Ninth Symposium on Rock Mechanics held at the Colorado School of Mines, Golden, Colorado, 17-19 April, 1967, chapter 3, pp. 45-78." Historical publication digitized from print 2017 [by Natural Resources Canada]. Includes bibliographical references. “The determination of the state of stress existing at a point in any solid body requires the determination of the six components of the stress tensor relative to a convenient set of axes. One general method of doing this in rock is to make strain or deformation measurements associated with local relief of stress in a number of boreholes penetrating a limited volume in the vicinity of the point at which the stress is to be determined. The stress is assumed to be constant throughout this volume. Leeman has described a number of the instruments that have been developed for making deformation or strain measurements in boreholes. Panek has described the application of statistical methods to the determination of the average components of ground stress from sets of measurements made in boreholes by means of deformation meters of the type developed by the U.S. Bureau of Mines. In this paper attention is given initially to the strain cell developed for use on the flattened ends of boreholes by the Council for Scientific and Industrial Research (CSIR), South Africa. The equations required for evaluating the average components of ground stress from measurements made by means of the CSIR strain cell are derived. These equations are similar in form to those applying to measurements made by the borehole deformation meter developed by the U.S. Bureau of Mines. The results of an investigation of the properties of the equations are described. These results are important in the practical use of both the instruments mentioned above and any instrument based on similar principles"--p. 45. gccst Mining industry gccst Rocks Toews, N. A. Canada. Natural Resources Canada. Canada. Department of Energy, Mines and Resources. Canada. Mines Branch. Reprint series - Dept. of Energy, Mines and Resources, Mines Branch ; RS 109 (CaOODSP)9.834843 PDF 2.73 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M38-8/M38-8-109-eng.pdf 300188