Numerical simulations of simple shear with non-coaxial soil models

This paper investigates the effects of a non-coaxial model on simulated stress-strain behaviour of granular materials subject to simple shearing under various initial conditions. In most cases, a significant difference of predictions between coaxial and non-coaxial modelling is found during the early stage in shearing. With the increase in shearing, non-coaxial simulations approach and tend to coincide with coaxial simulations. It is also found that the roles of non-coaxial modelling in simulating simple shear behaviour are considerably influenced by hardening rules, flow rules, initial static lateral pressure coefficients. In some cases, the non-coaxial modelling gives a similar simulation as the coaxial modelling. In other cases, the non-coaxial modelling decreases the hardening response or softening response of materials, compared with the coaxial modelling. Under certain conditions, the predicted peak strength of materials with non-coaxial modelling is larger than that for coaxial modelling. Some of these observations can be attributed to the amount of principal stress rotation in various cases analysed. Others can be attributed to the difference between the directions of the non-coaxial plastic flow and those for coaxial plastic flow.