Overconsolidated Stress and Strain Condition of Pavement Layers as a Result of Preloading during Construction

Abstract

The stiffness and resilient behavior of soils are essential input properties when designing pavements. There are many material models that take into account the stress dependency of stiffness. In pavements, horizontal stresses generally differ from conventional soils because of the preloading of the pavement during construction. In this research, standardized pavement cross sections were analyzed using finite element software with advanced soil constitutive models, and equations describing their behavior were calibrated with the back-analysis of in-situ and laboratory measurements. The pavement was modelled as comprising 4 layers: asphalt pavement, well graded crushed stone base course, granular subbase course and fine-medium sandy subgrade. The ratio of horizontal and vertical stresses σ3/σ1 and strains ε3/ε1 were investigated and assessed in the function of depth and loading, and recommendations are given for the description of these functions. The recommendations give useful input data for future practical applications such as simplified calculation methods that are capable of determining the permanent settlement beneath flexible pavements without the use of finite element methods.