Rail Crack Analysis with Inspection and Maintenance Plan at Transition Section Between Bridges and Embankments
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Date
2016-06
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Publisher
AAU
Abstract
Since railway is considered as optimal solution for the quickly growing transportation
demand its design, construction and maintenance should get proper attention. In rail
route design, we may need (be forced) to consider bridges and tunnels to pass obstacles
(especially in countries like Ethiopia). And emphasis must be given for transition section
like between bridges and embankments because when the railway route pass from
embankment to bridge or vice versa the track bed stiffness (modulus) varies causing
abrupt change in vertical deflection which intern leads to frequent high vertical force
exerted on the track structure, that cause more frequent damage to the track systems. So,
this study gives emphasis to the damage on rail occurring at this transition section
(specifically from embankment to bridge or vice versa).
The study uses ABAQUS and FRANC 3D software to determine the stress that occurs
on the rail at the transition section and the crack size (level of damage) respectively
together with analytical equation to get some important parameters used for the analysis.
Accordingly, the analysis results shows that due to the track bed stiffness difference the
crack will be 3.5 mm at the rail base and 2.5 mm at the rail head. However, in depth
experiments show that the rail can serve as long as the gap due to the crack is up to
70mm. Therefore, the probability of derailment happening is small. Even if the
derailment happening probability is less, as cracks can propagate with increased number
of cycles, the rail should be inspected and maintained frequently. From the numerical
investigation, the inspection frequency of the rail at the transition section should be four
times in a year (every three month).
Finally, the conclusions of the research are presented with recommendations for further
research by adding other factors that affect stiffness at transition sections.
Description
Keywords
Track Modulus, Embankment, Bridge, Stiffness, Transition Section, Vertical Deflection, Rail Damage