| Abstract: | Asphalt trackbed is gaining great popularity, as it strengthens the track tremendously and protects the subgrade. In this paper, asphalt trackbed deflection under moving dynamic load is solved analytically. The rail is modelled as an Euler beam. Tie and ballast are modelled as a discrete supporting system. Asphalt trackbed is modelled as another Euler beam on Winkler foundation (subgrade soil). One of the most important features of this model is that it can evaluate the damage to the asphalt trackbed under different train speed and/or non-uniform support conditions such as broken or missing tie case. It has the potential of serving as the design tool for asphalt trackbed as well as a track modulus back calculation tool for track structure evaluation. The solving techniques utilised in this paper can also be easily transformed to solve the dynamic responses of a track system on bridge. |
