Stress estimation in rock: a brief history and review

For this Special Issue of the Journal on Rock Stress Estimation, an introduction to the subject of in situ rock stress is presented here, concentrating on the history of the subject and the principles of both stress and its measurement. Following an historical overview of the need for rock stress information and the nature of rock engineering problems, stress and stress estimation are discussed. This is followed by a review of the stress measurement techniques. The importance of stress estimation and associated numerical modelling is highlighted. The conclusions emphasize the importance of a well-conditioned stress estimation campaign, by using more than one technique and supporting the campaign with a numerical model. The appendix focuses on the work at the Canadian Underground Research Laboratory.