A novel elastoviscoplastic model is proposed to improve the modelling of the one-dimensional unloading response of soils. Creep is modelled as an isotache process, but with the possibility to incorporate distortion of the isotaches after unloading. Upon unloading, swelling develops as a transient superimposed process that enables the sequential occurrence of swelling and creep as observed in experiments. The model features a flexible reference isotache to improve the fit to real laboratory tests. The model is implemented with full hydro-mechanical coupling and enables simulation of both load-controlled and strain rate-controlled stress paths. The model is calibrated with a laboratory test with a complex stress path including constant rate of strain, incremental loading and relaxation stages.

中文翻译：

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具有扭曲等距和膨胀的弹粘塑性建模，用于恒定应变率和增量加载

提出了一种新的弹粘塑性模型来改进土壤一维卸载响应的建模。蠕变被建模为一个等距过程，但有可能在卸载后合并等距变形。在卸载时，膨胀发展为一个瞬态叠加过程，使膨胀和蠕变连续发生，如实验中所观察到的。该模型具有灵活的参考等距线，以提高对实际实验室测试的拟合。该模型采用全液压机械耦合实现，可以模拟载荷控制和应变率控制的应力路径。该模型通过实验室测试进行校准，该测试具有复杂的应力路径，包括恒定应变率、增量加载和松弛阶段。