The Sliding-Rolling Granular Material Model and Its Integration
The stress–strain behavior of cohesive soil such as clay and that of cohesionless soil or granular materials such as sand share many common characteristics (e.g. pressure-dependency, critical state failure, and shear-induced dilation). However, some aspects of the stress–strain behavior of granular materials are very different from those of cohesive soils. For example, during an undrained (constant-volume) loading, granular materials may experience liquefaction (loss of effective mean normal pressure and/or loss of stiffness and strength), whereas cohesive soils do not. For this reason, a proper mathematical representation of the stress–strain behavior of granular materials requires a specific constitutive law. For instance, the Cam-clay model described in Chap. 12 is not suitable for granular materials. While the Drucker–Prager model may be used to represent some aspects (e.g. pressure-dependency), it is incapable of representing the others (e.g. density-dependent strain softening or liquefaction-induced softening).