The prediction of cyclic-driven accumulation of stress or strain in granular materials is difficult due to a number of subtile effects in the soil structure Also from the numerical point of view such prediction turns out to be troublesome because even small systematic errors of the general-purpose constitutive models are quickly accumulated A remedy could be a so called explicit model that treats accumulation as a kind of creep process especially for engineering problems like compaction or liquefaction. However, for a good assessment of accumulation a detailed definition of strain amplitude is required Consideration of the polarization and the openness of strain cycles on one hand and the degree of adaptation of the fabric on the other hand is crucial A novel "back polarization" tensor is introduced to memorize the history of cyclic deformation Multiaxial strain amplitude is defined considering the shape of the strain loop and rotation of principal directions of strain tensor Some experimental evidence for the assumptions made is provided Finally attempts to correlate the in-situ degree of adaptation with dynamic soil properties are reported.
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