Numerical Prediction of Permanent Deformation in Asphalt Track Foundation

초록

A hot mixed asphalt (HMA) layer is to be introduced as a trackbed foundation to provide greater bearing capacity onto track structure. Permanent deformations generated in the asphalt trackbed foundation are investigated in this study. A finite element (FE) prediction model was developed to simulate the permanent deformation performance of the asphalt track foundation. A concept of shakedown plastic modelling based on the conventional asto-plastic theory was adapted. Some factors affecting significant effects on permanent deformations of asphalt mixtures have been dentified. The general finite element program ABAQUS is used in this study. The computed plastic deformations, by finite element simulation, of the asphalt track model were compared to measured ones obtained from full-size load tests of the asphalt track, with increasing load repetition. The computed results show that the creep model available in the ABAQUS model library, and proposed model factors in this study, can adequately simulate permanent deformations of the trackbed foundations in-service.