Cold Regions Engineering
Extreme climatic conditions in the Earth's arctic and subarctic regions affect design of engineering infrastructure (roads and buildings). Designs commonly used in temperate regions often fail to survive low temperatures, frozen soil, ice, and freeze/thaw processes. Permafrost underlies approximately 24% of the exposed land surface in the northern hemisphere, including about 80% of Alaska. Permafrost is neither continuous nor homogenous; it varies in space, in time, and in water content. Ice inclusions interrupt masses of frozen soils with lower moisture content.
The circumpolar Arctic contains many of the Earth's remaining natural resources and is increasingly important to the world's economy. Road and building construction modify the microclimate at the soil surface and the underlying ice-rich permafrost often thaws so that surface structures collapse. Also, when permafost degrades, earthquake damage is greater, thermokarst landslides occur more often, and thawing coastal and riverine areas erode faster.
Climate change and the accelerated warming anticipated for Alaska and other northern regions will exacerbate permafrost-related difficulties. The U.S. Global Change Research Program's 2000 report pointed to permafrost thawing and loss of sea ice as two of the key issues facing Alaska in the 21st century. Climate models from the Canadian Climate Center and the Hadley Center predict Alaskan air temperature increases from 1-3 degrees C by 2030, well within the design lifetime of many structures and transportation systems. Temperatures are expected to rise throughout the next century. When such general temperature increases are added to local ones from construction disturbance, the rate of thaw beneath engineered facilities accelerates. Areas of open water near warming coastlines will increase the rate of thermal erosion and failures of coastal infrastructure. To develop effective strategies, new basic and applied research is needed.
This RFA includes several research areas that are linked by dependence on an understanding of heat transfer processes. It focuses on developing a basic understanding of fundamentals that will apply in transportation, industrial and municipal facilities, pipelines, resource extraction, and environmental conservation. Specific research foci include thermal protection of building foundations, frost heave and cryoturbation, thermal/mechanical properties of soils and geotechnical materials, and thermal erosion in soil and bedrock materials and sediment transport.