Parametric Study on Geogrid-Reinforced Track Substructure
Jeongho Oh
International Journal of Railway, vol. 6, no. 2, pp.59-63, 2013
Abstract : The purpose of this paper was to evaluate the effectiveness of geogrid for conventional ballasted track and asphalt concrete
underlayment track using PLAXIS finite element program. Geogrid element was modeled at various locations that include
subballast/subgrade, subballast/ballast interfaces, middle of the ballast, and one-third depth of the ballast. The results
revealed that the effectiveness of geogrid reinforcement appeared to be larger for ballasted track structure compared to
asphalt concrete underlayment track. Particularly, in case of installing geogrid at one-third depth of ballast layer in a conventional
ballasted track, the most effectiveness of geogrid reinforcement was achieved. The influence of geogrid axial
stiffness on track substructure response was not clear to conclude. Further validations using a discrete element method
along with experimental investigation are considered as a future study. The effect of asphalt concrete layer modulus was
evaluated. The results exhibited that higher layer modulus seems to be effective in controlling displacement and strain of
track substructure. However it also yields slightly higher stresses within track substructure. It infers that further validations
are required to come up with optimum asphalt concrete mixture design to meet economical and functional criteria.
Keyword : Geogrid, Ballasted track, Asphalt concrete underlayment track |