MODIFIED BOREHOLE JACK METHOD FOR ELASTIC PROPERTY DETERMINATION IN ROCKS

A method is described for the determination of the elastic parameters of rock from in situ tests using friction strain gauge and an extended borehole jack. Tangentially orientated friction strain gauges are positioned on opposite quadrants of the borehole, both other quadrants being fitted with a borehole jack, in order to measure load and deformation simultaneously. Equations are developed from which the modulus of elasticity of the rock mass is obtained. It is shown that a non-uniform pressure distribution and the plate-wall contact area have an insignificant effect on the accuracy of the results. Secondly effects are reduced by carrying out measurements only in the centre of the specimen. This new method has the same advantages as the established Goodman-Jack method. Of great importance is that the theoretical basis is exact. Although the method is only applicable for an ideal elastic material it can also be used for other in situ measurements in addition to the determination of the elastic modulus, for example linearity, anisotropy, inhomogenity, tensile strength and the primary stress condition. (TRRL)

• Corporate Authors:

  Springer Verlag

  175 5th Avenue
  New York, NY  United States  10010
• Authors:
  • Deeseler, G H
• Publication Date: 1978-4

Media Info

• Features: Figures; References;
• Pagination: p. 221-239
• Serial:
  • Rock Mechanics
  • Volume: 10
  • Issue Number: 4

Subject/Index Terms

• TRT Terms: Boreholes; Deformation; Field tests; Friction; Measurement; Mechanical elasticity; Modulus of elasticity; Physical properties; Rocks; Strain gages; Test procedures
• Old TRIS Terms: Insitu methods; Rock properties
• ITRD Terms: 5711: Bore hole; 5595: Deformation; 5452: Friction; 6226: In situ; 6136: Measurement; 5919: Modulus of elasticity; 4154: Rock
• Subject Areas: Geotechnology; Highways; I43: Rock Mechanics;

Filing Info

• Accession Number: 00309351
• Record Type: Publication
• Source Agency: Bundesanstalt für Straßenwesen (BASt)
• Files: ITRD, TRIS
• Created Date: May 21 1980 12:00AM