UBC Theses and Dissertations
A comparison of three techniques for the determination of deformation properties of rock Norrish, Norman Ian
Laboratory and in situ testing programmes to determine the deformation behaviour of three rock types have provided an opportunity for a comparison of three testing techniques. To aid future standardization, procedures and equipment for the laboratory testing, Goodman Jack testing and plate loading tests are presented in detail. Laboratory tests and plate loading tests show that the gneiss and schist rock types are well differentiated on the basis of deformation modulus. The ratio of average modulus for gneiss to schist is 2.0 from the laboratory testing and 5.6 for the plate loading tests. The Goodman Jack modulus values are similar for all rock types, the ratio of gneiss to schist being 1.3. Similarly the laboratory and plate loading tests show a wide range of values while the jack tests exhibit a very narrow range. The modulus results for the schist conform to the anticipated scale effect while the gneiss tests do not. It is concluded that the partial correlation between the three testing techniques reflects the need to quantify important factors such as rock quality and in situ stresses and to incorporate these factors into valid interpretive formulae. Anisotropy investigations for the laboratory and plate loading tests are consistent. The schist is approximately twice as rigid loaded parallel to the foliation than when loaded perpendicular to it. Anisotropy investigations with the Goodman Jack are qualitative only without very detailed geologic information at the test locations. Permanent deformations of the rock are consistent for the three testing methods and reflect the volume of rock influenced as well as the rock quality at the test location.
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