Permafrost and Related Engineering Problems in Alaska GEOLOGICAL SURVEY PROFESSIONAL PAPER 678 Permafrost and Related Engineering Problems in Alaska By OSCAR J. FERRIANS, JR., REUBEN KACHADOORIAN, and GORDON W. GREENE GEOLOGICAL SURVEY PROFESSIONAL PAPER 678 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1969 UNITED STATES DEPARTMENT OF THE INTERIOR WALTER J. HICKEL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress catalog-card No. 76-602920 First printing 1969 Second printing 1970 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 55 cents (paper cover) CONTENTS I 'age Abstract- ____ _________________________ 1 Engineering geology Continued Introduction. _ ________________________ 1 Engineering problems ____________________ 15 Permafrost- __ ________________________ 4 Thawing of permafrost ________________ 15 Definitions ________________________ 4 Frost heaving- _______________---__-- 17 Origin and thermal regime _________________ 5 Frost heaving of piles __________________ 17 Areal distribution and thickness ______________ 6 Specific structure- _______________------_ 17 Related geomorphic features ___________________ 8 Railroads- _________________________ 18 Polygonal ground- ______________________ 8 Highways and roads_ __________________ 21 Stone nets_ ___________________________ 8 Airfields ____^_____________________ 28 Solif luction_ __________________________ 9 Buildings- _ ________________________ 29 Thaw or thermokarst pits __________________ 12 Dams ____________________________ 32 Thaw lakes- __________________________ 12 Telephone and power transmission lines ______ 33 Beaded drainage ________________________ 12 Pipelines __________________________ 33 Pingos_ _ ____________________________ 12 Utilidors __________________________ 34 Muck deposits _________________________ 12 Icings- ______________________________ 34 Summary of geomorphic features- ____________ 14 Conclusions _____________________________ 36 Engineering geology-_______________________ 14 References cited _________________________ 37 ILLUSTRATIONS Page FIGURE 1. Map showing extent of permafrost zones in Northern Hemisphere ____________________________ 2 2. Map showing distribution of permafrost in Alaska- _____________________________________ 3 3. Block diagram showing where taliks can occur in relation to the active layer, suprapermafrost zone, permafrost table, and permafrost- ______________________________________________ 4 4. Diagrammatic sketch showing the effect of surface features on the distribution of permafrost in the con­ tinuous permafrost zone_ ____________________________________________________ 6 5. Diagram showing relation of amplitude of ground-surface temperature fluctuations to amount of thawing- _ _ 6 6. Diagrammatic sketch showing the distribution of permafrost in the discontinuous permafrost zone, Fairbanks area_ ___________________________________________________________ 7 7. Aerial photograph of coastal plain near Barrow, showing polygonal markings on ground surface caused by underlying ice-wedge polygons ______________________________________________ 8 8. Aerial photograph showing polygonal markings on ground surface (caused by ice-wedge polygons) in the vicinity of Meade River_ ____________________________________________________ 9 9. Photograph of ice wedge (ground ice) in permafrost exposed by placer mining near Livengood_ ________ 10 10. Aerial photograph of thermokarst mounds near Fairbanks- _________________--__----____--__ 11 11-15. Photographs of 11. Thermokarst mounds near Fairbanks-_________________________________________ 11 12. Sorted stone circles caused by frost action in Alaska Range _ __________________________ 11 13. Large mass of ground ice in silt bluff near Fairbanks- ______________________________ 12 14. Thaw or thermokarst pit near Fairbanks ________________________________________ 13 15. Shoreline of a thaw lake about 40 miles northwest of Glennallen ________________________ 13 16. Aerial photograph of pingo in Yukon-Tanana Upland- _____________________-___--------__ 13 17. Diagram showing effect of gravel fill upon thermal regime. ________________________________ 16 18. Map showing location of transportation routes in Alaska ___________________-_-_____---_--- 19 19. Photograph of differential subsidence of roadbed along the Murphy Dome Spur of The Alaska Railroad caused by thawing permafrost-_____________________________________ __________ 20 in IV CONTENTS Page FIGURE 20. Photograph of differential subsidence of roadbed of Copper River and Northwestern Railway-_ ________ 21 21. Map of the Moody area on The Alaska Railroad showing landslides and slumps caused by thawing of permafrost and remedial measures taken to combat them_ ______________________________ 22 22-27. Photographs of 22. Landslide area at mile 353.5, The Alaska Railroad- _________________________________ 23 23. Polygonal ground in permafrost exposed by removal of vegetation by a highway crew_ _________ 24 24. Thawed lake sediments flowing around blade of bulldozer- ___________________________ 25 25. Gravel road near Umiat showing severe differential subsidence caused by thawing of ice-wedge polygons in permafrost________________________________________________ 26 26. Slump block of fine-grained highway fill material near mile 113 on the Richardson Highway. _____ 27 27. Gully along edge of road caused by surface drainage thawing the permafrost in loess deposits- _ _ _ _ 28 28. Oblique aerial photograph of Chariot Site, northwestern Alaska- ____________________________ 29 29. Oblique photograph of tractor trail near Canning River, North Slope __________________________ 30 30. Photograph of frost-heaved piling of bridge ___________________________________________ 31 31. Geologic sketch of foundation conditions of frost-heaved bridge- _____________________________ 31 32-36. Photographs of 32. Frost-heaved steel-pile bridge- ______________________________________________ 32 33. Roadhouse, mile 278.5, Richardson Highway- _____________________________________ 33 34. The schoolhouse at Glennallen ______________________________________________ 34 35. Fracture due to frost heaving of 4-inch concrete foundation of apartment house, Fairbanks- _ _ _ _ _ 35 36. Utilidor under construction at Fort Wainwright __________________________________ 35 TABLES Page TABLE 1. Mean annual temperature and precipitation data from representative stations in Alaska- ____________ 7 2. Common topographic features that indicate ground conditions in arctic and near arctic regions- ________ 14 3. Hypothetical example of seasonal frost penetration into silt in central Alaska and possible upward push on 40-inch-perimeter pile (ground temperature constant) _______________________________ 17 4. Comparison of construction costs between permafrost and permafrost-free areas of the highway between Rex and Lignite, Alaska- ____________________________________________________ 22 PERMAFROST AND RELATED ENGINEERING PROBLEMS IN ALASKA By OSCAR J. FERRIANS, JR., REUBEN KACHADOORIAN, and GORDON W. GREENE ABSTRACT this remote and presently inaccessible region. Pre­ Permafrost, or perennially frozen ground, is a wide­ paratory work is under way for the construction of an spread natural phenomenon. It underlies approxi- 800-mile-long pipeline extending from the oil fields nately 20 percent of the land area of the world. The to Valdez, a year-round seaport. A winter road >ermaf rost region of Alaska, which includes 85 percent connecting Fairbanks with Sagwon on the Arctic >f the State, is characterized by a variety of perma- North Slope has been completed. These major engi­ 'rost-related geomorphic features including patterned neering activities are just a part of the overall con­ ground, pingos, thaw lakes, beaded drainage, thaw or struction effort that will take place in northern Alaska thermokarst pits, and muck deposits. Known perma­ because of the recent oil discovery and because of frost thickness ranges from about 1,300 feet near potential future discoveries of other natural resources. Barrow in northern Alaska to less than a foot at the All this activity requires an understanding of the southern margin of the permafrost region. The dis­ arctic environment, to establish sound cost-saving tribution of permafrost is controlled by climatic, engineering procedures and to preserve the natural geologic, hydrologic, topographic, and botanic factors. environment insofar as possible. In most areas The extensive permafrost region of Alaska poses where roads or buildings are constructed on perma­ special engineering problems for the design, construc­ frost, the procedures that cost the least in the long tion, and maintenance of all types of structures. Lack run are those that disturb the natural environment of knowledge about permafrost has resulted in tre­ the least, and therefore, are conservation oriented. mendous maintenance costs and even in relocation or Generally, the initial capital investment is greater abandonment of highways, railroads, and other struc­ when correct procedures are used; however, mainte­ tures. Because of the unique geologic-environmental nance cost is considerably less. If improper procedures conditions that exist in permafrost areas, special are used, expensive maintenance cost far exceeds the engineering procedures should be used, not only to additional expense of the initial investment, and in minimize disruption of the natural environment, but some cases, structures