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.

由于这些基础设施的结构和几何增强特性，在铁路中使用沥青细碴 (BS) 变得越来越重要。通常，在翻新过程中，由于时间跨度缩短，沥青混合物的摊铺质量控制会受到影响。为了验证显着气隙含量变化对铁路轨道机械响应的影响，本文对使用 BS 改造的巴西铁路进行了 3-D 数值模拟。首先，在实验室中对 BS 进行了表征以用于模型输入。然后，假设 BS 有两种本构行为，开发了 3-D 数值模型：线性弹性和线性粘弹性。还模拟了全颗粒轨道以进行比较。数值结果与实际的仪器测试部分进行了比较。正如预期的那样，使用 BS 时，减少了轨脚位移和路基上的应力。此外，本文评估的沥青混合物的不同空气空隙含量导致整体轨道响应的变化很小。