A state-dependent double yield surface elastoplastic constitutive model considering the effect of particle breakage

Numerous experimental studies have shown that particle breakage in granular geomaterials under loading alters the grain size distribution (GSD) and consequently affects their mechanical properties. Therefore, establishing a constitutive model that incorporates particle breakage is crucial for accurately predicting the stress-strain behavior of granular materials. First, this study derives a hyperbolic breakage evolution model based on the characteristics and limitations of Hardin's breakage evolution model and extensive test results and modifies the elastic compliance matrix (Ce) to account for particle breakage. Next, a critical state equation that considers particle breakage effects is established, effectively capturing the increasing slope of the critical state line due to particle breakage. This characteristic is incorporated into the state parameters, resulting in a plastic compliance matrix (Cp) that accounts for particle breakage. Finally, by combining the modified elastic and plastic compliance matrices, a state-dependent double yield surface elastoplastic constitutive model that considers particle breakage is developed and validated.