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Several case history failures of slope systems have highlighted that the instability onset in loose materials can be triggered under prevailed drained conditions and stress paths that can be represented by constant shear drained (CSD) loading. This study uses the anisotropic critical state theory (ACST) to assess the effect of fabric anisotropy and loading characteristics (e.g., Lode angle and principal stress direction) on the instability onset under CSD stress paths, comparing our numerical-based observations with available experimental information. Towards this end, the ACST-based SANISAND-F model’s performance under CSD stress paths is also assessed. In addition, multiaxial conditions are incorporated through the estimation of instability surfaces. The numerical simulations are useful in explaining that the instability onset under CSD loading is dictated by a trade-off of volumetric strain components. Moreover, the results show an important effect of fabric anisotropy on the instability stress ratio (𝜂𝑓 ). For conditions representative of common experimental setups, 𝜂𝑓 decreases with the increase of the Lode angle and the major principal stress inclination, and 𝜂𝑓 increases with the increase of initial fabric intensity, consistent with available experimental evidence. However, these trends can change based on the interaction between the Lode angle and loading/fabric directions; hence, departing from typical experimental observations. Finally, we discuss the potential of a simplified approach to estimate 𝜂𝑓 analytically, including fabric effects. 

Static liquefaction has been associated with the failure of several tailing storage facilities (e.g., the Brumadinho failure in 2019) and has been a persistent topic of discussion in the mining and tailings communities. Experimental studies have suggested that the onset of static liquefaction is dependent on the initial state (void ratio and confinement) and fabric anisotropy. In this context, traditional constitutive models developed under the critical state theory (CST) have been used to investigate the onset of static liquefaction for several complex loading paths. However, these models do not capture the effect of soil fabric anisotropy (inherent and induced) that are relevant in field conditions. In this study, the Anisotropic Critical State Theory (ACST) framework is used to assess the onset of static liquefaction in particulate materials, incorporating the effects of inherent and induced fabric. Our assessments derive an analytical criterion to assess static liquefaction that can be applied to screening assessments. The derived analytical criterion is a function of material properties, state, and fabric anisotropy, which couple the effects of fabric and loading direction. The use of the derived criteria in particulate materials is illustrated, and the implications of assessing the static liquefaction of mine tailings under generalized loading is also discussed.