Design of under sleeper pads for turnout

Recently unexpected unsymmetrical settlements of long concrete bearers occurred at turnouts in the Czech railway tracks. The changes of bearer position arise due to the high stresses in ballast under underneath surface of bearers ends. Under sleeper pads are included into turnouts to reduce stresses in ballast bed, to improve homogeneity of track stiffness and to avoid deterioration of track quality. The design of under sleeper pads for turnout is related to arrangement of concrete bearers. The main goal of the design is homogenization of rail vertical displacement under an axle force and homogenization of stresses in ballast bed. The main part of the paper is focused on the results evaluation of FEM analysis and their practical application in design of under sleeper pads.