Engineering challenge: build a road on permafrost

Engineering challenge: build a road on permafrost. . , Thermosyphons keep the permafrost frozen, Thompson Drive crosses areas of continually frozen ground, known as permafrost. If the permafrost thaws and settling occurs, the entire roadway structure, including sidewalks, curbs and the bridge over the railroad tracks, will become distorted and unusable., Self-powered refrigeration devices, called thermosyphons, help eliminate settlement from thawing by cooling the permafrost in the winter. Carbon dioxide boils in the lower portion of the thermosyphons. This process removes a large amount of heat from the surrounding permafrost. The carbon dioxide then passes to the upper portion of the thermosyphon where it is recondensed, releasing heat to the cold winter air outside., Hairpin thermosyphons are a new type used in Thompson Drive., The upper portions of the hairpins during construction , The entire device is now located beneath the pavement and no parts can be seen above ground. Heat is released just below the road surface so it can make its way to the cold winter air. As a result, the surrounding surfaces are much cooler, and lines from the thermosyphons can be seen when the road is frosty., How thermosyphons are oriented in relation to the road surface , [Diagram of roadway construction], An infrared image of the thermosyphons in operation , Infrared imaging is used to monitor the system's operation. The bright red and yellow stripes show the warmth created at the surface of the roadway by the release of heat from the thermosyphon condensers just below the surface. The blue-green colors indicate that the surrounding surfaces are much colder. This forces heat out into the surrounding air, which cools the permafrost below., Choosing a name for Thompson Drive , Thompson Drive is named in memory of Morris Thompson, his wife, Thelma and daughter, Sheryl. A distinguished Alaska Native leader, Morris served on the University of Alaska Board of Regents and was an ardent supporter of the university. Morris also served as president/CEO of Doyon from 1985-1999. Thelma was very supportive of Morris throughout his distinguished career. Her strong family values served her well in her role as mentor to many Native youth and in her volunteer service to her community. Sheryl, like her parents, was an organizer and a builder of bridges between cultures., UAF research bridges the gap between theory and practice , Research at the University of Alaska Fairbanks spans many disciplines, much of it focusing on issues that affect Alaskans and their way of life. UAF is recognized worldwide as a leader in arctic studies and related education.