Numerical analysis of railway substructure with geocell-reinforced ballast

With the commencement of high-speed trains in railway infrastructure, stresses throughout the railway substructure have increased. To have high bearing stress capacity, for construction of railway substructure, either use of high strength material or implementation of strength improvement techniques for substructure design is proposed. This study describes the process of development of the numerical model of railway substructure, focusing on its subgrade stress behaviour. In this study, a comparative numerical study for subgrade stresses of railway substructure with unreinforced and reinforced ballast was also conducted. The objective of this study is to understand the stress distribution in railway substructure with and without reinforcement due to train movement. The comparison study illustrates the inclusion of geocell in ballast as reinforcement and increment in its width, magnitude of stresses reaching subgrade is reduced and became uniformly distributed. Thus, it helps in constructing a better performing railway substructure with low strength ballast and soil subgrade. However, widening of geocell confinement is restricted, as higher confinement width results in stress accumulation on side-slope of ballast which may cause blowing of the constituent material.