Investigation of the Most Positions Affected in Rail Track When the Modulus of Elasticity of the Ballast Layer is Changed

Abstract The railway is one of the cheapest methods to transport people and heavy goods. It is safer than highways. In Iraq, many railways connect the south country with the middle and north, which are old, damaged, and need to continued maintenance. Iraq needs to construct new lines of the rail track with low-cost, less maintenance, and highly stable structure, which requires understanding the behavior of rail track under train loads and the pattern of distribution of deformations, stresses, and strains inside the body of rail track and know the layer which more effected by changing the strength of ballast layer by change modulus of elasticity of it. This paper investigates the influence of modulus of elasticity of the ballast layer on the behavior of railways and the positions of deformation, stresses, and strains in the rail track which is most affected by the change in the modulus of elasticity and the value of the effect. The finite element approach was considered in this study using Abaqus Ver. 6.14-4 program. The investigation outcomes displayed that when the ballast layer’s modulus of elasticity E increase by 100 MPa, the value of deformation in the rail track is affected in all layers, and the value of decreased is 6.8 % for rail, 6.9 % for ballast, and 6.7 % for the sub-ballast layer. Therefore the strain of the sub-ballast layer is affected by the change modulus of elasticity of the ballast layer more than other ballast and subgrade. Also, the result shows that stresses in the rail are the only part of the rail track affected by the change in the ballast layer’s modulus of elasticity E, while the other layers are unaffected. So the increase in E of the ballast layer affects the layer beneath it, which is the sub-ballast layer.