ABSTRACT
A new elastoplastic soil model has been developed for non-cohesive soils, meeting both the challenges of geotechnical problems and the demands of engineering practice. Based on the concept of bounding surface plasticity (Manzari and Dafalias 1997), it captures the state-dependence of basic soil behavioural patterns. For improving the model’s reliability with regard to fundamental and more complex stress paths, the original formulation has been extended with optional features. The increased shear stiffness after load reversals as well as its strain dependent degradation within the small strain range are taken into consideration. A corresponding state variable scales the plastic hardening modulus of the kinematically hardening yield surface. An additional cap yield surface accounts for the evolution of plastic strains in constant stress ratio loading. In order to ease the model’s application in routine design, a parameter calibration procedure internally determines selected bounding surface parameters. The implementation in an open source environment ensures public availability with potential for further development.
