000 02880cam  2200361za 4500
0019.840844
003CaOODSP
00520221107151937
007cr |||||||||||
008170801s1972    oncd    ob   f000 0 eng d
040 |aCaOODSP|beng
041 |aeng|bfre|bger
043 |an-cn---
0861 |aM38-8/110E-PDF|zM38-8/110
1001 |aGray, W. M.
24510|aStress determination from strain relief measurement on the ends of boreholes |h[electronic resource] : |bplanning, data evaluation and error assessment / |cW.M. Gray and K. Barron, Mining Research Centre.
260 |aOttawa : |bInformation Canada, |c1972.
300 |a10, [8] p. : |bcharts
4901 |aReprint series ; |vRS 110
500 |aCover title.
500 |a"Reprinted from Proceedings of the International Symposium on the Determination of Stresses in Rock Masses, Lisbon, 19-21 May 1969, pp. 183-199 [...]."
500 |aHistorical publication digitized from print 2017 [by Natural Resources Canada].
504 |aIncludes bibliographical references.
520 |a"The method of strain-relief measurement on the flattened ends of boreholes is a relatively economical means for determining stress deep in rock. Experience with the method has enabled the mechanical and statistical problems of instrument design, planning the measurement system, evaluating the results and assessing the errors to be better appreciated. Use of a four-element 45-degree strain-gauge rosette is recommended. Borehole configurations for optimum precision with this and other rosette designs are given. Since it may be impractical to use an optimum configuration at a given site, a series of layouts suitable for a variety of sites is presented. An order of preference is given. Experimental methods of checking the validity of strain measurements and a statistical method for final screening of data are given. Currently, the greatest errors in the method are caused by uncertainty about the values of the calibration factors or stress concentration factors associated with flat ended boreholes. A review of recent work on this problem has yielded recommended calibration factors, with their degree of uncertainty. The sensitivity of the calculated stress components to the values of the calibration factors is illustrated by an example"--Summary, p. 1.
546 |aIncludes parallel titles and summaries in French and German.
69207|2gccst|aMining industry
69207|2gccst|aRocks
7001 |aBarron, K.
7101 |aCanada. |bNatural Resources Canada.
7101 |aCanada. |bDepartment of Energy, Mines and Resources.
7101 |aCanada. |bMines Branch.
830#0|aReprint series - Dept. of Energy, Mines and Resources, Mines Branch ;|vRS 110|w(CaOODSP)9.834843
85640|qPDF|s2.42 MB|uhttps://publications.gc.ca/collections/collection_2017/rncan-nrcan/M38-8/M38-8-110-eng.pdf