Numerical analysis of deformation and stability in the formation for railway tracks
Over the past few decades, the increasing demands of railways operations in the form of heavy loading and high speed have been noticed. Railway formation and ballast deform progressive under heavy axle cyclic loading, therefore the rail track needs proper design of ballast and formation bed to achieve the desire stiffness and stability for the safe and sound serviceability of the track. For the overall stability of the track on soft formation, the ground is improved by different techniques prior to the construction on that, in order to avoid the failure and differential settlement during the designed trains operation. The numerical analyses illustrate that the total deformation and bearing capacity of the railway tracks mostly depend on the changes in the friction angle and cohesion of the selected soils of the subgrade. To avoid failure in the formation of track under the design loads, the proper selection of types of soils, its layer thickness, well compaction during construction and provision of proper track drainage system are extremely important. For the construction of new railway tracks the soils having greater values of friction angle, cohesion and elastic stiffness with the well graded ballast cushion under the sleepers of designed side slopes can be used to reduce the maintenance cost, considerably increase the life time of the components of the tracks and ultimately give better performance of the tracks.