EFFECTS EVALUATION OF SUBGRADE STIFFNESS ON BEARING CAPACITY OF GRANULAR ROADBED WITH DDA

Abstract

The paper proposes a new analytical procedure with discontinuous analysis to estimate the bearing capacity of granular roadbed used in ballasted track or road pavement. To examine the applicability, a series of numerical simulations bearing capacity tests for 1/5 scale model of real ballasted track were performed with DDA that regards a particle of crushed stone as an irregular polygon. Based on the comparison of analytical results with experimental results, the effect of subgrade stiffness on the bearing capacity of granular roadbed was examined. As the result, it is revealed that the subgrade stiffness has a great influence on the bearing capacity of granular roadbed, and that discontinuous analysis is an effective method to simulate the mechanical behavior of granular roadbed if the subgrade which behaves as a continuum can be approximated with discontinuous modeling well.