A state-dependent dilatancy model for cemented sand

Abstract

A modified stress–dilatancy model for cemented (or bonded) sand is developed to account for the effects of stress, density, bonding and debonding. The model is developed based on the critical state theory and state-dependent dilatancy theory. The critical state locus of the cemented sand corresponds to its initial cement content. Most importantly, a newly established bonding-state stress ratio is proposed to incorporate the effects of the bonding and debonding mechanical properties. The bonding-state stress ratio was determined using the initial bonding strength, initial confining stress, and current deviator strain. The initial bonding strength, which corresponds to the initial cement content reflects the strength enhancement caused by the bonded intergranular contacts after sample preparation. The current deviator strain reflects the gradual bonding breakage caused by the development of deviator shear deformation; the initial confining stress is adopted for normalization. Detailed processes of model development and parameter calibration are reported. The reliability of the model is analyzed by simulating a series of experimental datasets for cemented sand. This indicates that the proposed model can capture the strength–dilatancy of cemented sand under different values of stress, density, and bonding states.