Permanent Deformation Characteristics and Prediction Model of Silty Subgrade Soils under Repeated Loading

Abstract

By using dynamic tri-axial testing, permanent plastic strain curves of silty subgrade soil under 104 repeated loading were tested with three water content levels, two compaction degree levels and three deviator stress levels. The effect of the above mentioned factors on permanent subgrade deformation were compared in quantity. A large number of literal investigation and testing data regression analysis show that Tseng and Lytton’s constitutive model can successfully predict accumulative permanent deformation of silty subgrade soil. Moreover, all above testing data were regressed to build the formation for calculating model coefficients of silty soil by using water content and resilient modulus. Hence the constructive model for predicting permanent deformation of silty soil subgrade was obtained, which can be used to analyze total permanent deformation of asphalt pavement.