Evaluation of actions on concrete sleepers as design loads - influence of fastenings.

In Greece, during the 1980s, 60% of the twin-block concrete sleepers designed for lines of mixed traffic and a maximum speed of 200 km/h, which were laid on a track with a maximum operational speed of 140 km/h, presented serious cracks. The existing theories could not justify the appearance of these cracks since the theoretically calculated actions on sleepers were much lower than the limit values. In this paper, a model for the determination of the load acting on the track's superstructure is presented. The basic parameters of concrete sleeper design considering the most adverse conditions of a railway network are investigated, and a methodology for calculating the load undertaken by each sleeper is proposed. Finally, numerical applications on twin-block and/or monoblock sleepers are presented, including the use of fastenings of high resilience. [ABSTRACT FROM AUTHOR]