Calibration of Hypoplastic Parameters – Two Different Aspects

Abstract

Numerical modeling serves as a widely utilized method for addressing geotechnical concerns. A pivotal aspect of this modeling process is the accurate characterization of material behavior. The connection between stress and strain tensors within soil is explicated by the soil constitutive equation, which is reliant on factors like soil type and deformation circumstances. One notable model is hypoplasticity, which has been in use for more than three decades. This research aims to calibrate the hypoplastic parameters for Danube sand using the SoilTest Module of PLAXIS. The constitutive hypoplastic model for Danube sand was fine-tuned through a series of numerical simulations. The parameter calibration occurred twice: initially according to 5 cycles of hysteresis loop of stress–strain diagram of cyclic triaxial testing, and then subsequently in accordance with strain trends observed after ten thousand cycles. A comparison was drawn between parameters determined from the overall strain trends and those calibrated based on the five cycles. The findings indicate that while the model calibrated during a specific segment of testing can accurately predict strain values during compression and extension, it falls short in forecasting the accumulated settlement following prolonged cyclic loading. This suggests the model’s limited capability in anticipating long-term cyclic load effects on settlement behavior.