Three-dimensional numerical modelling of railway track with varying air voids content bituminous subballast

Abstract

The use of bituminous subballast (BS) in railways has gained importance due to structural and geometrical enhancing properties of these infrastructures. Oftentimes, during renovations the paving quality control of bituminous mixtures is compromised due to reduced time span. To verify the effects of significant air voids content variation on the mechanical response of railway tracks, this paper performed a 3-D numerical modelling of a Brazilian railway renovated with BS. First, the BS was characterised in laboratory for model inputs. Then, 3-D numerical models were developed assuming two constitutive behaviour for the BS: linear elastic and linear viscoelastic. An all granular track was also simulated for comparisons. Numerical results were compared with actual instrumented test section. As expected, displacements on foot-of-rail and stresses on the subgrade were reduced when using BS. Moreover, the different air voids content of the bituminous mixture evaluated herein caused low variation in the overall track response.

GRAPHICAL ABSTRACT

KEYWORDS:

• Railway track
• bituminous subballast
• air voids
• linear viscoelasticity
• numerical simulation

Acknowledgements

The authors would like to acknowledge the financial support of Brazilian Coordination for the Improvement of Higher Education Personnel (CAPES) and National Council for Scientific and Technological Development (CNPq); as well as the support on the construction and monitoring of the railway sections by MRS Logistics and the Laboratory of Pavement Technology of Polytechnic School of the University of São Paulo.

Disclosure statement

No potential conflict of interest was reported by the author(s).