Stability and Deformation of Infrastructure Affected by Global Warming
Project Duration: 2018 – Present
Collaborators & Partnerships:
Thermal loading and seasonal freeze-thaw cycles in highly plastic clay foundations can produce large non-recoverable (i.e. permanent) vertical and horizontal deformations, leading to instability and settlement problems for embankments in warm permafrost zones. Moreover, the stress and deformation of the clay core and foundation can also be influenced by potential permanent slow-rate deformations (i.e. creep) of highly plastic clay. Currently, construction and maintenance of roads in northern Manitoba follow practices similar to those in southern, non-permafrost areas. Alteration of the surface conditions disturbs the sensitive natural environment and changes the rate of heat transfer into the previously frozen ground. For an appropriate design of transportation infrastructure in seasonally freezing soils as well as in permafrost regions, it will be crucial to develop a non-isothermal stress-strain relationship (constitutive law) for freezing and thawing soils that includes the effects of the strength and deformation of frozen soil. Also, the effect of creep for freezing soils needs to be considered in the constitutive relationship (Elastic-ThermoViscoPlastic (E-TVP) constitutive law). In addition, further research is needed to evaluate the potential for future movements of embankments due to permafrost degradation using coupled Thermo-Hydro-Mechanical (THM) modeling in freezing soils. The goal will be to provide remedial measures to increase stability and minimize movements.
This research will include numerical modeling as well as innovative laboratory tests. The new model will be used to investigate the condition of permafrost or seasonal frost beneath earth dams and embankments in northern Canada as well as their settlement and lateral movement by considering different climatological scenarios for the next 25 years. The goal is to develop the most suitable and economically efficient remedial measures for infrastructure built on degrading permafrost.