Railway subgrade performance during flooding and the post-flooding (recovery) period
Autor: | W. John McCarter, Peter Keith Woodward, Mohammad Menan Hasnayn, G. Starrs, David Connolly |
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Rok vydání: | 2017 |
Předmět: |
Ballast
Engineering Suction business.industry Flooding (psychology) 0211 other engineering and technologies Transportation 02 engineering and technology Subgrade Geotechnical Engineering and Engineering Geology Track (rail transport) Recovery period 021105 building & construction Cyclic loading Geotechnical engineering business Water content 021101 geological & geomatics engineering Civil and Structural Engineering |
Zdroj: | Transportation Geotechnics. 11:57-68 |
ISSN: | 2214-3912 |
Popis: | Railway track is constructed on compacted soil which is, characteristically, unsaturated. The performance of the subgrade, both in the short- and long-term, is dependent on environmental factors, in particular, an increase in subgrade moisture content due to high rainfall can result in subgrade distress or shear failure under cyclic loading (i.e. train passage). Furthermore, due to varying climatic conditions, subgrade soil may fluctuate between a saturated and unsaturated condition. It is necessary, therefore, to understand such soil behaviour to ensure a safe and economical design and in the planning of maintenance work. Previous research has focused on the effect of water on the superstructure, but not the substructure. This paper outlines a full-scale testing programme to study track performance after flooding and, subsequently, during a 2, 4 and 6 week recovery (drying) period. The study investigated the influence of soil suction on subgrade behaviour with measurements made using the filter paper technique, whilst subgrade modulus was measured using the plate load test. The results show that subgrade behaviour is influenced by changes in water content associated with soil suction; particularly, when wetted from a dry state. It is also found that tamping is less effective in the presence of wet/low-stiffness subgrade soil. |
Databáze: | OpenAIRE |
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