Stress studies for permanent deformation calculations

An analytical-mechanistic method for the calculation of permanent deformations in unbound pavement layers and subgrade has recently been developed in Technical Research Centre of Finland. The objective was to develop a relatively simple calculation method with a material model, which tie together permanent deformations to the most important effecting factors. The material model has been generated from the test results of accelerated pavement tests along with the complementary laboratory tests. This approach has created a new, important view to the research. The objective of this study is to compare the stress analysis done with the 3D and 2D modeling. The comparison of the 3D and 2D axisymmetric modeling showed that in the upper part of the pavement modeled with axisymmetric 2D overestimates stress responses. The stress analysis also proved that different non-linear elasto-plastic material models need separate material parameter C.