Reloading In Barodesy Employing The Asymptotic State Boundary Surface

The reloading behaviour of the soil is dominated by effects of the recent deformation history as well as by the overall stress history, indicated by overconsolidation. The stiffness of an overconsolidated soil is higher than the stiffness of normally consolidated soil. In basic hypoplastic and barodetic models, the stiffness for reloading is underestimated, and thus so-called ratcheting effects appear. In this article, we propose a relation to improve the reloading behaviour of barodesy: we introduce an extension, which increases the stiffness in dependence of the distance to the asymptotic state boundary surface and the current dilatancy. Thus, within an intermediate strain range, the stress-strain behaviour is improved and ratcheting effects are significantly reduced. The behaviour of the proposed extension is verified by simulation of typical element tests and validated by a comparison with experimental results.