Abstract: Stabilizer-treated soil possesses unique structures due to the cementation of soil particles and cement-hydrate. Compared with remolded normally-consolidated soil, treated soil usually holds a strong structure and overconsolidation ratio. Treated soil exhibits softening behavior due to the loss of cementation induced by the decay of bonded structure during the development of deformation. An evolution rule of cementation effect is proposed to consider the change of cementation strength with shear strain. The hardening parameter in UH model is modified and an elastoplastic constitutive model incorporating cementation effect for stabilizer-treated soils is proposed, in which non-associated flow rule is used. The comparison between predicted mechanical behaviors of cement-treated soil and lime-treated soil with triaxial compression test results indicate the validation and accuracy of the proposed model. Consideration of the contribution of cementation effect can describe the mechanical behaviors of stabilizer-treated soils. The soil behaves like overconsolidated soil due to the cementation strength, while the softening is faster with the decrease of cementation strength during deformation.

Key words: treated soil, structure, overconsolidation, cementation strength, dilatancy, softening, unified hardening parameter