Re-examination of the In Situ Stress Measurements on the 240 Level of the AECL’s URL Using Tensor-Based Approaches

Excerpt

In situ stress is an important parameter in rock mechanics and often displays significant variability in fractured rock masses (Day-Lewis 2008; Hyett 1990; Martin 1990; Matsumoto et al. 2015; Obara and Sugawara 2003). Therefore, rigorous statistical approaches for stress variability characterisation are essential components and prerequisites for adequate interpretation of stress measurements. However, currently in rock mechanics, stresses are customarily processed by analysing the principal stress magnitude and orientation separately (e.g. Brown and Hoek 1978; Hakami 2011; Hast 1969; Herget 1988; Lisle 1989; Zhao et al. 2013). As previous works show, these customary scalar/vector approaches violate the tensorial nature of stress and may yield erroneous results (Dyke et al. 1987; Gao 2017; Gao and Harrison 2016b, 2017, 2018b, c; Hudson and Cooling 1988; Hudson and Harrison 1997). …