Analysis of a railway turnout system with a spot replacement sleeper

The behaviour of a railway turnout system when one of the sleepers is replaced with a fibre composites sleeper is analyzed to simulate the spot replacement maintenance strategy. In the analysis, the rails and the sleepers are modeled as a simplified three dimensional grillage beam system with the sleepers as beams on elastic foundation. The most critical sleepers in the railway turnout system were assigned with a modulus of elasticity (MOE) of 4 GPa while keeping the elastic modulus of the other sleepers the same. The analysis showed that a spot replacement sleeper with a low MOE leads to a lowering overall stiffness of the railway track. It resulted in a reduction in the bending moment and shear and an increase in the vertical deflection of the sleeper directly under the rail seat load. Results also showed that a spot replacement sleeper material with an MOE of 4 GPa will distribute the load evenly in the neighboring timber sleepers