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

• Published in: Road materials and pavement design Vol. 23; no. 2; pp. 414 - 432
• Main Authors: de Freitas Alves, Talita, Moraes Pereira, Paulo André, Motta, Rosângela, Vasconcelos, Kamilla, Teixeira, Jamilla Lutif, Bernucci, Liedi
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01-02-2022; Lavoisier
• Subjects: air voids; Asphalt mixes; bituminous subballast; linear viscoelasticity; Mathematical models; Mechanical analysis; Numerical models; numerical simulation; Quality control; Railway track; Railway tracks; Renovation; Subgrades; Three dimensional models; Voids
• ISSN: 1468-0629; 2164-7402
• DOI: 10.1080/14680629.2020.1828150

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.