... is built on or in the ground. In addition it forms an important part of extractive industries, such as open cast and underground mining and 1 Norbert R. Morgenstern, University of Alberta, Edmonton, canada, T6G2G7 hydrocarbon extraction and is essential in evaluating natural hazards such as earthquakes...

...), Wawersik (1973) and da Fontoura (1980). Most of the existent data are based on creep tests performed on relatively intact rock. Exceptions are Lama (1974) and Kaiser and Morgenstern (1979) who present qualitative information on the time dependent behavior of jointed rock-like material. The present paper...