OPTIMAL DESIGN AND ANALYSIS OF PRE-STRESSED CONCRETE SLEEPERS

Abstract

The track system consists of structural components
like a sleeper that has to be designed to accommodate
the maximum tonnage. The main function of a sleeper
is to transfer the load from the rail to the ballast via
the rail pad and to the under laid formation. The
analysis and design of concrete sleepers requires the
assessment of load on the sleepers, ballast pressure
distribution, selection of the dimensions of the sleeper
and moment calculations at critical sections. In this
paper a pre-stressed pre-tensioned concrete sleeper
having an optimal shape, strength and tendon type
and profile with reference to the existing sleeper type
that is used by the Ethiopian Railways Corporation
(ERC), which is the new type II Chinese sleeper, was
analyzed and designed. Moreover, FEM modeling of
pre-stressed concrete sleepers was conducted. The
optimal design output of this research shows that increasing
the concrete grade results an increase in
sleeper capacity but has no more effect on moment
capacity which is largely dependent on the section
dimension of the sleeper, tendon strength and eccentricity.
The final optimized design outputs and analysis
result of the existing sleepers are compared with
respect to raw material consumption for production
and its capacity