Effect of H-beam and double channel sleeper spacing and positioning on steel girder railway bridge using FEM

Sleeper spacing has long been a critical consideration in railway engineering, with structural safety concerns typically restricting spacing to a maximum of 600 mm for ballasted tracks and steel girder railway bridges. Most prior research has studied ballasted track systems, leaving a gap in guidance for non-ballasted configurations. This study addresses this gap by examining sleeper spacing on a non-ballasted steel girder railway bridge using influence line analysis to evaluate bridge response under moving loads. The analysis incorporates the dynamic augmentation factor per bridge rules to account for dynamic effects. A regression model is developed to predict cost savings based on sleeper spacing, achieving an R² value of 99%. Validation of FEM simulations is performed. Various response variables are studied, such as vertical bridge deflection and stresses in critical elements, including the main girder, rail, and sleepers. The study compares H-beam and double-channel sleepers under standard moving load cases from Indian Railways bridge guidelines. The effect of the positioning of sleepers over the bridge is also considered. Results indicate that maintaining sleeper spacing beyond 600 mm is feasible for non-ballasted bridges, offering potential reductions in manufacturing energy, carbon emissions, and construction costs.