Experiment and Model Prediction of State-Dependent Mechanical Characteristics of Cemented Soil

Mixing soil with a certain amount of binding agent can form artificial cemented soil with remarkable structure, which is widely used in the improvement of natural geomaterials. However, the existence of structure often induces cemented soils to appear more complex mechanical characteristics than remolded soil, and it is necessary to achieve quantitative analysis and reasonable prediction of their mechanical behaviors. This paper focuses on the common mechanical characteristics of cemented soil, the triaxial compression and shear tests of cement-bonded soil with different initial states are carried out, and then the state dependence of its mechanical characteristics is systematically analyzed. Finally, the state-dependent model is used to calculate/predict its mechanical behavior. The research results show that: (1) The peak shear stress ratio of cemented soil is significantly affected by its initial state (void ratio, confining pressure, cementation), while the residual shear stress ratio is less affected by the initial state, indicating that the residual strength can be used as a state-independent mechanical parameter; (2) The isotropic consolidation curves of cemented soil is significantly affected by the initial state (void ratio, cementation), but the damage of structure makes these compression curves gradually converge to that of remolded cemented soil, indicating that the consolidation curve of the remolded cemented soil can be used as the inherent compression curve; (3) The isotropic compression and triaxial shear test results of the above-mentioned cemented soils with different initial states show an encouraging agreement with date by calculation, indicating that the state-dependent constitutive model here can reasonably describe the complex mechanical behavior of cemented soil.