Load stepping schemes for critical state models

Abstract

This paper investigates the performance of various load-stepping schemes for finite element analysis with critical state soil models. The accuracy of simple incremental schemes is found to be strongly influenced by the load increment size, the type of flow rule, and the overconsolidation ratio. Similarly, these factors are shown to have a pronounced effect on the efficiency and stability of some classical iterative schemes. Unless they are performed with small load steps, critical state analyses with fixed increment sizes frequently exhibit non-convergent behaviour or lead to inaccurate solutions. The automatic incrementation schemes developed by Abbo and Sloan (International Journal for Numerical Methods in Engineering 1996; 39:1737–1759; Proceedings of 5th International Conference, Owen DRJ, Onate E, Hinton E. International Center for Numerical Methods in Engineering, Barcelona, 1997; 1:325–333), which are based on standard methods for integrating systems of ordinary differential equations, are shown to be efficient, accurate and robust solution techniques for a wide variety of critical state problems. Copyright © 2001 John Wiley & Sons, Ltd.