ABSTRACT

The paper studies the effectiveness of a drift reduction method in integrating unsaturated soil models. The drift reduction is based on the NICE (Next Increment Corrects Error) method. The NICE method can be applied to any explicit stress integration method based on Runge-Kutta method. The performance of the stress integration enhanced by the NICE scheme is demonstrated with the Barcelona Basic Model. Numerical studies in this paper involve the integration of the Barcelona Basic Model with different numbers of strain increments and different sets of model parameters and initial conditions. The improved algorithm does not require any significant computations, thus the drift reduction is virtually accomplished without significant cost. The reduction in the yield surface drift appears to be rather significant, suggesting that under normal circumstances no additional drift correction method is required.