Behaviour of the aeolian sands under true-triaxial conditions

To clarify the stress–strain behaviour, strength on the deviatoric plane, shear band formation, and dilatancy characteristics of aeolian sand under three-dimensional loading conditions, a series of true-triaxial tests with various intermediate principal stress coefficients b ∈ [0.0, 1.0] at constant effective mean principal stress p' were conducted under drained and undrained conditions. The results presented that the variations of the stress–strain, strength, and effective internal friction angle show its significant dependence on the relative magnitude of the intermediate principal stress expressed in terms of the b value. Because a clear penetrating shear band was produced in the prismatic specimen at b = 0.2 and b = 0.4, the stress–strain response exhibits softening, and its peak shear stress and effective internal friction angle are reduced. Besides, shear bands often appear in the hardening regime. Moreover, the dilatancy was the weakest at b = 0.0 and the strongest at b = 0.4, which depended on the stress path in terms of the b value. The peak shear stress on the deviatoric plane decreased in a transverse “S” shape with the b value varying from 0.0 to 1.0, correspondingly, the effective internal friction angle increased first and then decreased. But in the case of increasing p' value, aeolian sand has a unified critical state line and phase transformation line at constant b value.

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Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025)