Analysis and Design of Prestressed Concrete Sleeper
No Thumbnail Available
Date
2014-11
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The track system consists of structural components like sleeper that has to be designed to
accommodate the maximum tonnage. The main function of sleeper is to transfer the load from
the rail to the ballast via the rail pad and to the under laying 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 followed by bending moment calculations at rail seat
and center section of sleeper and finally checking of the stresses in sleeper ensuring the factor of
safety. The aim of this paper is to analyze and design a pre-stressed pre-tensioned concrete
sleeper having an optimal shape, strength and tendon type and profile with reference to the
current sleeper type which is used by ERC. The existing sleeper length, fastening system,
spacing and area of reinforcement are maintained constant. The research is done by conducting
literature review related to this paper work, design data and input parameters are collected from
ERC, analysis of the existing sleeper have been made, proceeding the parametric optimization of
new model with respect to geometry (shape), concrete grade, pre-stressing tendon type and
profile. The optimization output 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. Increasing the diameter of the
tendons has direct relation on sleeper capacity and inversely related to pre-stresses losses which
exceed the maximum limit beyond a certain magnitude (9mm diameter). The shape of the sleeper
is investigated based on the ballast pressure which shows wider dimension at the end and
tapering to the center; the reduction is gradual to avoid stress concentration. The final optimized
design outputs and analysis result of the existing sleeper are compared with respect to raw
material consumption for production and its capacity. The analysis and design of turnout
sleepers, sleepers with additional rails, the effect of the length and spacing of sleeper on its
capacity, and the fastening system with relation to lateral and longitudinal loading are
recommended for further researches.
Keywords: Analysis and Design, current (existing) sleeper, modeling, optimization, prestressed
concrete sleeper
Description
Keywords
Analysis and Design; current (existing) sleeper; modeling, optimization; prestressed concrete sleeper