Effects of climate change on soil embankments for transport infrastructure

The climate is changing. Unequivocal global warming has brought significant changes to our climate system. The Intergovernmental Panel on Climate Change [1] concludes that climate change will result in both an increase in temperature and changes in the global water cycle, possibly leading to extreme drought–rainfall conditions and freeze–thaw cycles. These developments raise important questions: can existing transport infrastructure such as high-speed railway lines built on soil embankments cope with the aforementioned extreme weather conditions? Do we have enough reliable physical data to design future transportation systems?

This paper describes a novel environmental chamber capable of simulating, in a geotechnical centrifuge test, the effects of extreme cycles of temperature, rainfall and humidity on an embankment in flight. Using the recently developed centrifuge environmental chamber, a series of centrifuge tests were carried out to assess the influence of thermal cycles on the deformation mechanisms of soil embankments, the influence of extreme drought–rainfall conditions on the stability of embankment slopes, and slope deterioration mechanisms under freeze–thaw cycles. The thermo-hydro-mechanical behaviour of embankments is reported and discussed. Furthermore, new insights into the deformation and failure mechanisms of embankment slopes are revealed, and the design implications for future transport infrastructure are highlighted and discussed.