USGS Professional Paper 545-A, Text
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Effects on Transportation and Utilities Eklutna Power Project GEOLOGICAL SURVEY PROFESSIONAL PAPER 545-A This page intentionally left blank THE ALASKA EARTHQUAKE, MARCH 27, 1964: EFFECTS ON TRANSPORTATION, COMMUNICATIONS, AND UTILITIES Effect of the Earthquake Of March 27, 1964, on The Eklutna Hydroelectric Project, Anchorage, Alaska By MALCOLM H. LOGAN With a Section on TELEVISION EXAMINATION OF EARTHQUAKE DAMAGE TO UNDERGROUND COMMUNICATION AND ELECTRICAL SYSTEMS IN ANCHORAGE ByLYNN R. BURTON GEOLOGICAL SURVEY PROFESSIONAL PAPER 545-A APR 11 1991 UNITED STATES DEPARTMENT OF THE INTERIOR STEW ART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1967 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402- Price 35 cents (paper cover) THE ALASKA EARTHQUAKE SERIES The U.S. Geological Survey is publishing the results of its investigations of the Alaska earthquake of March 27, 1964, in a series of six professional papers. Professional Paper 545 describes the effects of the earthquake on transportation, communications, and utilities. Where needed to complete the record, reports by individuals from organizations other than the Geological Survey are included in the series. Thus, this description of the Eklutna Hydroelectric Project-a key part of south-central Alaska's power system-was requested from the U.S. Bureau of Reclamation; so, too, was the section on the use of television for investigating damaged under ground utility lines. Additional chapters in Professional Paper 545 will describe the effects of the earthquake on The Alaska Railroad and on highways, airports, utilities, and communications. Other professional papers describe the field investigations and reconstruction and the effects of the earthquake on com munities, on regions, and on the hydrologic regimen. CONTENTS Page Page Page Abstract ____________________ _ A1 Effects-Continued Television examination of earth Introduction and ackno" ledg- Penstock, surge tank, and quake damage to underground rnents _____________________ _ 1 anchor block ___________ _ A13 communication and electrical Geologic setting ______________ _ 4 Powerplant and associated systems in Anchorage, by Lynn R. Burton ____________ _ The first 24 hours ____________ _ 5 structures _____________ _ 15 A25 Introduction_____________ _ 25 Effects on indiYidual features Tailrace _________________ _ 20 Underground systems _____ _ 25 of the Eklutna project ______ _ 6 Transmission lines ________ _ 23 Eqmprnent ______________ _ 25 Eklutna Darn ____________ _ Substations ______________ _ 6 23 Procedure _______________ _ 27 Intake structure __________ _ 6 Other earthquake effects in the Damage to systems _______ _ 27 area ______________________ _ Tunnel and gate shaft ____ _ 9 23 Interpretation of data _____ _ 30 ILLUSTRATIONS FIGURES Page 1. Index map of the Eklutna 14. Photograph of Eklutna power- 24. Photograph showing darnaged Hydroelectric Project ___ _ A2 plant before the earthquake_ A15 pump in project office_____ A20 2. Topography and surface ge 15. Photograph showing piling 25. Typical section of tailrace ology of the project area __ 3 in the powerplant founda- channeL ___ - ____ -------- 20 3. Schematic plan and profile of tion _____ --_____________ 15 26. Photograph showing cleaning- the Eklutna project _____ _ 4 16. Geologic section through up operation at outlet of 4. Map and section of darnsite surge tank, penstock, and tailrace conduit ____ - __ --- 21 area showing exploratory powerhouse_____________ 16 27. Plan, section, and chart giv- work __________________ _ 7 17. Typical ground settlement ing summary of damage 5. Photograph of spillway gate resulting from the earth- to tailrace conduiL _ _ _ _ _ 21 structure _______________ _ 7 quake__________________ 17 28. Aerial photograph showing 6. Aerial photograph of intake 18. Plan view of powerplant locations of cracks near area showing network of g1vmg measurements of the powerplant_ _ _ _ _ _ _ _ _ _ 22 cracks _________________ _ 8 settlement and deflection_ 17 29. Aerial photograph showing 7. Geologic section showing lo 19. Photograph of machine-shop Eklutna Lake area_______ 24 cation of earthquake darn- foundation, showing sep 30. Photograph of truck-mounted age to intake structure __ _ 9 aration of backfill mate- television equipment being 8. Geologic section along the rial from concrete footing_ 18 loaded at Denver for its line of the pressure tunneL 10 20. Photograph showing damaged flight to Anchorage______ 25 9. Photograph of debris depos 20,000-kva transformer con- 31. Details of television probes_ 26 ited in Eklutna tunneL __ 12 duit and terminal box____ 18 32. Arrangement of television 10. Geologic section through gate 21. Photograph showing damaged equipment during exami- shaft __________________ _ 12 heating-system piping in nation__________________ 27 11. Geologic sect1on through the floor of the automotive 33. Topographv, surface geol surge tank _____________ _ 13 repair shop______________ 19 ogy, and location of frac 12. Section through surge tank, 22. Sketch map of major earth- tures in underground penstock, and anchor- quake cracks in power- communication and elec- block area _____________ _ 14 plant area_ _ _ _ _ _ _ _ _ _ _ _ _ _ 19 trical systems___________ 28 13. Photograph showing earth 23. Photcgraph ~howing cracks 34. Axial view of breaks in the settlement over penstock in pavement of Eklutna ducts, as seen on the tele- anchor block ___________ _ 14 roadway__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 20 vision monitor screen_____ 30 v THE ALASKA EARTHQUAKE, MARCH 27,1964: EFFECTS ON TRANSPORTATION, COMMUNICATIONS, AND UTILITIES EFFECT OF THE EARTHQUAKE OF MARCH 27, 1964, ON THE EKLUTNA HYDROELECTRIC PROJECT, ANCHORAGE, ALASKA By Malcolm H. Logan, U.S. Bureau of Reclamation ABSTRACT The March 27, 1964, Alaslm ea:r!th ported from Eklutna Dake .to the power consolidated sediments and overburden quake and its a:ssoctalted aftershocks plant rut tidewa:ter on Knik Arm of Oook which densified and subsided during the caused damage requiring several milHon Inlet by an underwater intake con earthquake. Structures built on bed dolLars worth of repaiir to the Eklwtna nected to a 4.46-mile tunnel pel113tock. rock experienced little or no damage. Hydroelectric Project, 34 miles north The primary damage caused by the Underground communication and elec ea:st of Anchorage. Electric service earthquake was 1at the intake struc!ture trical .systems in Anchorage were exam 1lrom the Eklutna powerplant was inter in Eklutna Dake. No damage to the ined with a small-diameter television rupted during the early phase of the power tunnel wa•s observed. The pile camera to locate damaged areas requir Mal'ch 27 eal'thquake, bu:t was restored •suppor.ted powerplant •and appurtenant ing repair. Most of the damage wars (intermittently) until May 9,1964, when structures, Anchorage and Palmer sub concentrated at or near val'ley slopes. the plant was closed for inspection and stations, and the transmission lines suf Those parts of the sy·stems within the repair. fered minor da.mage. Most damage major rslide area's of the city were Wa:Der for Eklutna project is trans- occurred to facilities constructed on un- destroy·ed. INTRODUCTION AND ACKNOWLEDGlVIENTS The Eklutna Hydroelectric The lake is 7 mi1les long and is fed Although this report does not Project is a 30,000-kw (kilowatt) hy meil't walter from Eklutna Gla discuss earthquake-damage reha power development designed and 'Cier, 4 miles above the lake, and by bilitation, the repair of facilities constructed by the Bureau of Rec precipitation runoff from 'a 119- damaged by the great Alaska lamation, U.S. Department of the square-mile watershed. Wruter is earthquake of March 1964 was dif Interior, to bring urgently needed ·transported from the lake by an ficult, hazardous, and costly. electric power to the rapidly ex underwa'ter intake connected to a Transmission poles had to be set panding metropolitan area at An 4.46-mile tunnel and 'tunnel pen on steep icy mountain slopes; ~horage, Alaska. The project was ~stock through Goat Mountain to weakened precast-concrete con constructed during the 4-year pe the pawerplant (figs. 1, 2, 3) . The duits could be strengthened only riod 1951-55. The powerpl'ant project is for power production by working under 40 feet of near (fig. 1) is loca,ted 34 miles north only. Transmission lines, opel"at freezing water; and sand and erust of Anchorage on the Glenn ing a;t 115 kv (kilovolts) and ter gravel were mucked from 4.46 Highway and is supplied by water minruting at subst:ation facilities, miles of 9-foot tunnel requiring from Eklutna Lake, about 10 miles extend north to Prulmer and south access by means of a 220-foot by road from the Glenn Highway. to Anchorage from the plant. vertical ladder. A1 A2 ALASKA EARTHQUAKE, MARCH 27, 1964 CANADA 1000 MILES 1.-Index map of the Eklutna Hydroelectric Project. EFFECTS ON EKLUTNA HYDROELECTRIC PROJECT, ANCHORAGE EXPLANATION I I I - ./ FLOOD PLAIN 1$:::.:.</i< Glacial till Graywacke containing argillite inclusions Greenish-gray metagraywacke Thin-bedded argillite and some thin beds of graywacke Contact -,-I--75 Fault, approximately located Showing dip of fault plane 73 _L Strike --and- dip of beds Shattered zone o33 Drill hole 10 Test pit 700u 0 700 2100 FEET CONTOUR INTERVAL 500 FEET 2.-Topography and ourfare geology of the project area. ALASKA EARTHQUAICE, MARCH 2 7, 19 64 ' diameter gate shaft 115-kv transmission H igh-water line PLAN 3.-Schematic plan and profile of the Eklutna project. The decisions, actions, and im- of flow of electric energy. Juneau, Alaska, to W. Williams, provisions of Alaskan personnel This report was prepared in the project superintendent, Anchor- during the emergency and subse- Enginwring Geology Division of age, Alaska, and to their staffs quest repair operation have since the Chief Engineer's Office, U.S.