Foundation Design of Wind Turbines in Southwestern Alaska, a Case Study

• Main Authors: Lorie M. Dilley, Laurie Hulse
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: permafrost; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.524.7914; http://www.confmanager.com/communities/c680/files/hidden/Papers/Ren-13, Foundation Design of Wind Turbines.pdf

cooperative providing power to 51 Alaska villages, has made a concerted effort to install wind turbines in their villages in an effort to mitigate the growing costs of electrical power generation. The subsurface for the turbines in several of these villages consists of sands and silts with ground temperatures of between 30 and 32 0F. The presence of warm, degrading permafrost has required innovative foundation designs, including the use of helical piers to support a steel and concrete foundation. The community of Kasigluk is a case study where three wind turbines have been installed. Uplift forces imposed on the foundations were approximately 100 kips. The design piers were 20 inches in diameter and installed 36 to 40 feet deep with two 36-inch diameter helices. The piers were installed in Kasigluk in April 2006 by STG, Inc. An uplift pile load test was conducted on the installed piers in order to determine the actual working load that each pier can sustain. The wind turbines in Kasigluk are currently operational. Refinement of the design continues for other villages that are slated to have wind turbines installed. Index Terms — foundations, helical pier, permafrost, wind turbines