STUDY ON IMPROVED ELASTO-PLASTIC MODEL FOR UNSATURATED SOILS BASED ON BARCELONA BASIC MODEL

Jianjun Dong

Department of Civil Engineering College of Mining Engineering Liaoning Technical University, Huludao, China 125105

The strength and deformation behaviours of unsaturated soil can be approximately described by elasto-plastic constitutive model that was proved by abundance academic and test researches. The Barcelona elastic-plastic model is an excellent model that can simulate the strength and deformation of unsaturated soil. But their calculated result of shear strength is low. So an improved BBM model is settled by using drop-shaped shear yield surface and hardening theory of dual stress. The results show that the improved model can more accurately predict the strength and deformation behaviours of unsaturated soil under suction-controlled triaxial compression stress states.