Effects on Transportation and Utilities 

Alaska 

Highway System 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 545-C 
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THE ALASKA EARTHQUAKE, MARCH 27, 1964: 

EFFECTS ON TRANSPORTATION, COMMUNICATIONS, AND UTILITIES 

Effects of the Earthquake of 

March 27, 1964, on the 

Alaska Highway System 

By REUBEN KACHADOORIAN 

A description of the severe damage to the 

highways and bridges in south-central Alaska 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 545-C 
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEW ART L. UDALL, Secretary 

GEOLOGICAL SURVEY 

William T. Pecora, Director 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1968 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402- Price 65 cents (paper cover) 
... 

THE 

ALASKA EARTHQUAKE 

SERIES 

The U.S. Geological Survey is publishing the results of 

investigations of the earthquake in a series .of six professional papers. Professional Paper 545 describes the effects 

of the earthquake on transportation, communications, and 

utilities. Chapters in this volume already published include 

one on the Eklutna Hydroelectric project in Anchorage and 

one on airports, utilities, and corrununications. A forthcoming chapter will describe the effects on The Alaska Railroad. 

Other professional papers, already published, describe the 

field investigations and reconstruction, and the effects of 

the earthquake on communities, on regions, and on the 

hydrologic regimen . 

CONTENTS 

Page Pago Page Abstract _____________________ C1 Effects of the earthquake-Con. Geologic factors influencing 

Introduction __________________ 1 Damage to roadways-Con. damage intensity ____________ C43 

Fieldwork ________________ 2 Landslides ____________ C26 Grain size of sediments ____ 43 

Acknowledgments _________ 2 Avalanches _____ · ______ 27 Thickness of sediments _____ 44 

Effects of the earthquake _______ 2 Sand ejecta blankets __ 27 Depth of water table ______ 44 Geologic setting ___________ 2 Seismic sea waves _____ 27 Amount of compaction _____ 44 Summary of damage _______ 2 Tectonic subsidence ___ 29 Liquefaction of sediments __ 45 Damage to roadways ______ 4 Damage to bridge ap- Fractures _____________ 11 proaches and bridges _____ 29 Lateral displacement _______ 46 

Origin of fractures _____ 18 Seismic shaking _______ 32 Engineering factors influencing 

Subsidence of roadway_ 19 Seismic sea waves _____ 42 damage intensity ____________ 47 

Lateral displacement of Regional subsidence Summary ___________ .. ________ 49 

roadway ___________ 26 and local subsidence_ 43 References cited _____ -- ________ 49 

ILLUSTRATIONS 

FIGURES 

Page Page 

1. Index map showing earthquake epicenter and lo- 13, 14. Photographs· of centerline fracture: 

cation of highways in south-central Alaska ___ _ C3 13. Seward-Anchorage Highway between 

2-7. Maps showing route of- Portage and Twentymile River________ C 16 

2. Sterling Highway and part of SewardAnchorage Highway, and effects of the 

earthquake upon the highways _______ _ 

3. Part of Seward-Anchorage Highway, the 

Hope Road, and the Portage Glacier 

Road, and effects of the earthquake upon the highways _______________________ _ 

4. Glenn Highway, and effects of the earthquake upon the highway _____________ _ 

5. The Edgerton Highway and part of the 

Richardson Highway, and effects of the 

earthquake on the highways __________ _ 

6. Copper River Highway and Point Whitshed 

Road, and effects of the earthquake 

upon the highways __________________ _ 

7. Highways on Kodiak Island, and effects of 

the earthquake upon the highways ___ _ 

8-11. Graphic logs of test holes: 

8. Snow River Crossing of Seward-Anchorageiiighway _______________________ _ 

9. Seward-Anchorage Highway ___________ _ 

10. Copper River Highway ________________ _ 

11. Richardson Highway __________________ _ 

12. Schematic drawing of types of fractures 

generated by earthquake in roadways __ 

5 

6 

7 

8 

10 

11 

12 

13 

14 

15 

14. Unpaved Copper River H:ghway at 

south approach of Clear Creek bridge 

329________________________________ 17 

15. Photograph of fractures normal to and along 

highway edge, Copper River Highway ____ ---_ 18 

16. Photograph of complex fractures with relatively 

large lateral and vertical displacement of 

sediments, Copper River Highway __ --- ___ ---- 19 

17-19. Pre- and postearthquake profiles: 

17. Mile 0.7 to mile 2.5, Richardson Highway_ 20 

18. Mile 5.9 to mile 11.0, Copper River Highway ______ .__________________________ 21 

19. Mile 75.1 to mile 85.0, Seward-Anchorage 

Highway___________________________ 23 

20. Pre- and postearthquake pier elevations and profiles at Snow River Crossing, Seward-Anchorage 

Highway__________________________________ 24 

21-24. Photographs: 

21. Bridge pier for new crossing at Snow 

River _______________ ·_______________ 24 

22. Arched bridge at Snow River Crossing___ 25 

23. Vertical displacement of roadway southeast of Ingram Creek on the SewardAnchorage Highway__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 26 

v 
VI CONTENTS 

21-24. Photographs-Continued Page 

24. Small landslide on Seward-Anchorage 

Highway near mile 44.5____________ C27 

25. Map showing pre- and postearthquake shorelines 

and area of inundation by seismic sea waves on Kodiak Island_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 28 

26. Photograph showing Point Whitshed Road destroyed by seismic sea waves________________ 30 

27. Photograph of Portage on Seward-Anchorage 

Highway during 28-foot tide___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 30 

~8. Map of Turnagain Arm showing pre-earthquake 

shoreline based on mean high water, and the 

area inundated by the 33-foot tide of April 14, 

1964______________________________________ 31 

29. Schematic drawing showing various elements of. a bridge____________________________________ 32 

30-45. Photographs: 

30. Subsidence of bridge approach fill, SewardAnchorage Highway_________________ 33 

31. Bridge 2, mile 27.1, on Copper River 

Highway__________________________ 33 

32. Mound formed by bulldozing of approach 

fill against bridge deck, Copper River 

Highway___________________________ 34 

33. Wreckage of Portage Creek bridges 2 and 

3, Seward-Anchorage Highway_______ 35 

34. Collapsed bridge across Twentymile 

River_____________________________ 36 

35. Overhead at east side of Snow River 

Crossing___________________________ 36 

36. Million Dollar Bridge, Copper River 

Highway; No.4 span off No.4 pier___ 37 

37. Collapsed No. 4 span and horizontal 

fracture in No. 4 pier of Million Dollar 

Bridge, Copper River Highway_______ 38 

33-.45. Photographs-Continued Page 

38. Broken rail piles on Scott Glacier 6 

bridge, mile 9.5, Copper River Highway_______________________________ C39 

39. Collapsed bent and deck of Copper River 

5 bridge, mile 35.0, Copper River 

Highway__________________________ 39 

40. Collapsed deck on Copper River 5 

bridge, mile 35.0, Copper River Highway_______________________________ 40 

41. Contact between steel truss and concrete 

deck on pier 26, Copper River 2 bridge, 

mile ~7.1, Copper River Highway____ 40 

42. West abutment of Scott Glacier 5 bridge, 

mile 9.2, Copper River Highway_____ 41 

43. East abutment of Scott Glacier Creek 5 

bridge at mile 9.2, Copper River Highway_______________________________ 41 

44. North abutment of Clear Creek bridge 

329, mile 41.0, Copper River Highway_ 42 

45. Collapsed bridge across Kenai River at 

Kenai Lake, mile 48.9, Sterling Highway_______________________________ 43 

46. Sketch of boring locations and pre- and postearthquake penetrometer tests at Snow River 

bridge 605, mile 17.7, Seward-Anchorage Highway______________________________________ 45 

47. Chart showing type of bridge, foundation material, and intensity of damage to bridges on 

Seward-Anchorage and Copper River Highways_____________________________________ 47 

48. Photograph of north abutment of Copper River 

9 bridge, mile 36.1, Copper River Highway, 

showing displacement of deck laterally to the 

left relative to substructure__________________ 48 

TABLES 

1. Estimated cost of repairs or replacement of highway structures damaged by the Alaska earthquake ____________________________________ _ 

2. Effects of the Alaska earthquake upon roads and 

bridges in south-central Alaska ______________ _ 

3-6. Foundation material and major effects of Alaska 

earthquake on the roadway: 

3. Seward-Anchorage Highway ___________ _ 

4. Sterling Highway _____________________ _ 

5. Glenn Highway ______________________ _ 

6. Richardson Highway __________________ _ 

7-11. Analyses of sediments: 

7. Snow River Crossing, Seward-Anchorage Highway __________________________ _ 

8. Miles 78.4, · 79, and 80.8 on SewardAnchorage Highway ________________ _ 

9. Miles 84.2, 86.6, 89.6, · 90.0, and 90.4 on 

Seward-Anchorage Highway _________ _ 

10. Underlying Copper River Highway _____ _ 

Page 

C4 

4 

53 

53 

54 

54 

55 

55 

56 

56 

7-11. Analyses of sediments-Continued 

11. Richardson Highway from mile 1.00 to 

mile 2. 78 __________________________ _ 

12. Correlation of foundation material and fractures 

of roadway of Seward-Anchorage Highway from 

mile 7 5.1 (Ingram Creek) to mile 95.0 _______ _ 

13. Bridges in south-central Alaska severely damaged 

or destroyed by the Alaska earthquake _______ _ 

14. Intensity of damage to bridges on primary and 

secondary roads in south-central Alaska ______ _ 

15-19. Damage to bridge approaches and bridges along15. Copper River Highway ________________ _ 

16. Seward-Anchorage Highway ___________ _ 

17. Glenn Highway from Anchorage to Richardson Highway ____________________ _ 

18. Richardson Highway from Valdez to Glenn 

Highway __________________________ _ 

19. Sterling Highway _____________________ _ 

Page 

56 

57 

58 

58 

59 

62 

64 

65 

66 
THE ALASKA EARTHQUAKE, MARCH 27, 1964: EFFECTS ON TRANSPORTATION, 

COMMUNICATIONS; AND UTILITIES 

EFFECTS OF THE EARTHQUAKE OF MARCH 27, 1964, ON THE 

ALASKA HIGHWAY SYSTEM 

The great earthquake that •struck 

Alaska about 5 :36 p.m., Alaska standnrd time, Friday, March 27, 1964 

(03 :36 :1.3.0, Oreemvich mean time, 

March 28, 1964), severely crippled the 

highway system in the south-central 

part of the State. All the major highways and most secondary roads were 

impaired. Damage totaled more thal!. $46 

million, well over $25 million to bridges 

and nearly $21 million to roadways. Of 

the 204 bridges in south--central Alaska, 

141 were damaged; 92 were severely 

damaged or destroyed. The earthquake 

damaged 186 of the 830 miles CYf roadway in south-"central Alaska, 83 miles so 

severely that replacement or relocation 

was required. 

IDartbquake damage to the roadways 

and ·bridges was chiefly by (1) seismic 

shaking, (2) compaction of .fins as well 

as the underlying ·sediments, ( 3) 

lateral <llspla·cement of the road!way 

and bridges, ( 4) fractures, ( 5) landslides, (6) aval-anches, (7) inundation 

by seismic 'Sea waves, (8) •scouring by 

seismic sea waves, (9) regional tectonic 

su:bsidence, causing inundation nnd erosion by ·high tides in sttbsided areas. 

The intensity of damage was controlled .primarily by the geologic environment (including the depth of the 

The great earthquake that struck 

Alaska at about 5 :36 p.m., Alaska 

standard time, Friday, March 27, 

1964 ( 03 :36 :13.0 Greenwich mean 

time, March 28, 1964) severely 

crippled the highway system in the 

By Reuben Kachadoorian 

ABSTRACT 

water table) upon which the highway 

structures rested, ·and secondarily 'bY 

the engineering characteristics of the 

structures. 'Structures on ·bedrock were 

only slightly damaged if at nll, whereas 

those on unconsolidated sediments were 

slightly to severely damaged, or were 

completely destroyed by seismic shaking. The low-lying areas underlain by 

saturated sediments, ·such as the Snow 

River Crossing ·and Turnagain Arm 

sections of the ·Seward-Anchorage 

Highway, were the most severely damaged stretches of the highway system 

in south-central Alaska. At Snow River 

and Turnagain Arm, the sediments 

underlying the roadway are fine 

grained and the water table is shallow. 

These factors were responsible for the 

intense damage along this stretch of 

the highway. 

All the bridges on the Copper River 

Highway except for one on bedrock 

were damaged ·by seismic shaKing. 

Lateral displacement of sedimenrc.tl toward n free face, which placed the 

bridges in compression, was the chief 

cause for the damage. This type of 

failure was extensive and widespread 

throughout the highway system. 

The chief engineering characteristics 

responsi·ble for the type nnd intensity 

INTROD,UCTION 

south-central part of the State. 

This part of Alaska has approximately 60 percent of the total 

population and produces more 

than 55 percent of the State's gross 

product and revenue. Thus, the disof damage include ( 1) thickness of 

roadway fills, (2) ty·pe of pile bents 

and masonry piers, (3) the weight ratio 

between the substructure ·and superstructure, and ( 4) the tie ·between the 

substructure and superstructure. 

The thicker the roadway fills, the 

more severe the damage. Wood piles 

did not break as extensively as piles 

constructed of three railroad rails 

welded together. Bridges that had relatively heav;y superstructures, for example those with concrete decks on 

wood piles, were more severely damaged 

than those with all-wood or concrete 

decks on concrete piers. Failure first 

occurred at the tie between the superstructure and the substructure ; the 

poorer this tie, the sooner the failure. 

Seismic sea waves destroyed 12 

bridges on the Chiniak Highway on 

Kodiak Island, one bridge on Point 

Whitshed road near Cordova, and about 

14 miles of roadway. 

The combination of regional tectonic 

subsidence and local subsidence and 

compaction of sediments caused inundation of many miles of highway by high 

tides, especially around Turnagain 

Arm. Total subsidence -in some places 

amounted to more than 13 feet. 

astrous effects of the earthquake 

upon the highway system materially affected the economy of the 

whole State. After the seismic 

shaking and .attendant seismic sea 

waves had stopped, much of the 

C1 
C2 

highway system lay in ruins. 

Roadways ·were fractured or were 

blocked by avalanches; locally 

they had sunk out of sight or had 

been washed away. Most of the 

bridges were damaged and many 

were completely destroyed. Some 

of the destroyed bridges lay in the 

creeks and rivers they once 

spanned; others had been washed 

away. This destruction isolated 

communities on the Kenai Peninsula from Anchorage and the rest 

of the State. On· Kodiak Island, 

Chiniak wa.S isolated from the 

town of Kodiak. 

In south -central Alaska there 

were, at the time of the earthquake, 830 miles of primary and 

secondary roads with 204 bridges. 

Approximately '186 miles of roadway and 141 bridges were damaged; 88 of the 186 miles was 

severely damaged. Ninety-two 

bridges required replacement. Total damage amounted to about 

$46,798,292 (Bruce A. Campbell, 

written commun., 1965). 

ALA$KA EARTHQUAKE, MARCH 2:7, 1.964 

The Alaska Department of 

Highways responded quickly to 

the emergency, and by early summer of 1964 all damaged routes 

were passable. The only section of 

road not reopened by the fall of 

1966 was the Copper River Highway between the Copper River 

(mile 27.1} and the Million Dollar 

Bridge (mile 49.0). 

FIELDWORK 

During the summer of 1964, the 

author examined all bridges and 

roadways of the Richardson 

High way between Valdez and 

Glennallen, Sterling Highway, 

Hope Road, Glenn Highway between Anchorage and the Richardson Highway, Copper River 

Highway, and Seward-Anchorage 

Highway (fig.1}, and, in addition, 

most of the roadways on Kodiak 

Island. 

The author was assisted during 

the study by the following memhers of the Geological Sur;vey : 

George Plafker on the Copper 

River and part of the Richardson 

Highways, M.G. Bonilla on parts 

of the Glenn and Seward-Anchorage Highways, and Roger Waller 

on parts of the Sterling and 

Seward-Anchorage Highways. 

Thor Karlstrom and Helen Foster 

furnished some data on the 

Seward-Anchorage and Sterling 

Highways. Richard Lemke collected and furnished the data on 

the Snow River Crossing on the 

Seward-Anchorage Highway. 

ACKNOWLEDGMENTS 

This report could not have been 

completed without the cooperation 

of, and the data supplied by, Bruce 

Campbell and Ralph Migliaccio 

of the Alaska Department of 

Highways, the U.S. Army, the 

U.S. Navy, and the numerous residents of Alaska who provided the 

eyewitness accounts. 

EFFECTS OF THE EARTHQUAKE 

GEOLOGIC SETTING 

The terrain over which the highway system in south-'Central 

Alaska passes is varied, and this 

variation played an important role 

in the. type and extent of damage 

to roadways and bridges. The 

terrain, in turn, is controlled by 

the geologic environment. 

In general, the highways are 

underlain by bedrock consisting 

primarily of argillite and graywacke or by unconsolidated material composed of glacial debris, 

swamp deposits, stream deposits, 

colluvium, and tidal deposits. 

With few exceptions, the lowlying areas that the highways 

cross are underlain by unconsolidated deposits, and most of the 

damage to the highway system was 

in these low-lying areas. The 

water table is close to the surface 

where the highway skirts a body 

of water or where it crosses tidal 

or deltaic deposits, especially on 

the Seward-Anchorage Highway 

at the head of Turnagain Arm and 

where the highway crosses the 

Snow River delta at the south end 

of Kenai Lake. 

SUMMARY OF DAMAGE 

The earthquake that shook 

south-central Alaska on March 27, 

1964, had a magnitude of 8.4. Its 

epicenter was at lat 61.06° N. and 

long 147.44° W., and its depth was 

about 21 kilometers (U.S. Coast ·-

and Geodetic Survey, 1966) . Although there have been earthquakes of equal or greater magnitude, the damage created by the 

Alaska earthquake was particularly devastating because the shaking lasted 4 to 5 minutes. The 

effects of this earthquake upon the 

highway system in south-central 

Alaska were staggering. All the 

major highways and most of the 

secondary roads were damaged; 

these include the Sterling, SewardAnchorage, Glenn, Edgerton, 

Richardson, Chiniak, Copper 

River Highways, and Point Whitshed Road. 
EFFECTS ON THE HIGHWAY SYSTEM C3 

A s I( 

0 F A 

r.. F 

l] 

0 50 100 MILES 

I I I I 

0 50 100 Kl LOM ETERS 

I I I \ 

. ... _j58" 

152" 144" 

I.-Index map showing earthquake epicenter and location of highways in south-central Alaska. 

281-012 0-68--2 
C4 

The total cost of repairing the 

highway system in south-central 

Alaska, including Kodiak Island, 

was estimated at $46,798,292 (table 

1), $20,898,816 for roadways, and 

$25,899,4 76 for bridges. About 186 

of the 830 miles of primary and 

secondary roads and 141 of the 204 

bridges in the area were damaged 

(table 2) ; 88 of the 186 miles was 

severely damaged. 

ALASKA EARTHQUAKE, MARCH 2.7, 1964 

The roadways and bridges were 

damaged by ( 1) seismic shaking, 

(2) fracturing, (3) compaction of 

sediments, ( 4) lateral extension or 

displacement of sediments, ( 5) 

compression of bridges, (6) landslides, (7) avalanches, (8) seismic 

sea waves, (9) regional subsidence, 

(10) erosion, and (11) postearthquake scouring and erosion by the 

TABLE 1. Estimated cost of repairs or replacement of highway structures damaged by the 

Alaska earthquake t 

Highway 

Copper River _______________________ ~ 

Glenn ______________________________ _ Ilope Road _________________________ _ 

Portage Glacier Road ________________ _ Point Whitshed Road ________________ _ Richardson _________________________ _ 

Seward-Anchorage _________ .. _________ _ Sterling ____________________________ _ 

Kodiak Island (Chiniak Ilighway, Anton 

Larsen Bay Road, Pasagshak Bay 

Road, Chiniak Ilighway to Spruce Cape via Kodiak) _________________ _ 

Secondary roads~---------------------

Total ________________________ _ 

Roadway 

$4,253,089 

682,812 

152, 194 

590,888 

50, 793 

1, 261,034 

9,606,405 

2,947,657 

1, 116, 108 

237,836 

20,898,816 

Bridges 

$19,175,596 

41,957 

318, 375 

32, 165 

277, 176 

5, 264, 762 

602, 116 

183, 175 

4, 154 

25,899,476 

Total 

$23,428,685 

724, 769 

152, 194 

909,263 

82, 958 

1, 538, 210 

14, 871, 167 

3, 549, 773 

1,299, 283 

241,990 

46, 798, 292 

1 This estimate differs from that given by Eckel and Schaem (1966, p. 49). The estimate given above is based on a 1965 revision and does not include Federal aid for secondary roads in towns. 

TABLE 2.-Effects of the Alaska earthquake upon roads and bridges in south-central 

Alaska 

Roadway Bridges 

Highway or road 1 Damage Total (miles) Number 

(miles) Total damaged Total Severe 

Copper River Ilighway _____________ _ 59 45 30 53 52 

Edgerton Ilighway ________________ _ 40 0 0 4 1 Glenn Ilighway ___________________ _ 188 16 2 21 11 Ilope Road _______________________ _ 16 0 0 _2 0 

Keriai-Nikishka Road ______________ _ 30 0 0 1 0 

Portage Glacier Road ______________ _ 7 7 1 3 3 

Point Whitshed Road ______________ _ 9 2 2 5 1 

Richardson Ilighway _______________ _ 115 40 5 20 8 

Seward-Anchorage Ilighway ________ _ 130 35 25 54 39 Sterling Ilighway __________________ _ 145 11 5 13 5 

Kodiak Island: 

42 6 6 20 15 

10 5 472 4 2 

· Chiniak Ilighway ________________ _ Anton Larsen Bay Road _________ _ Saltery Cove Road ______________ _ 14 3 3 0 0 

Pasagshak Bay Road ____________ _ 

Chiniak Ilighway to Spruce Cape 

15 5 472 3 3 

via Kodiak ___________________ _ 10 1 0 1 1 Secondary roads ___________________ _ 10 0 

Total ______________________ _ 830 186 88 204 141 

1 Only primary and secondary highways listed. Streets and bridges in communities not included. 

inundating seas in the low-lying 

coastal areas. 

This report will not discuss in 

complete detail the extensive damage to the highways, but, instead, 

will attempt to correlate the damage with the geologic environment, 

and, for bridges, also with the engineering characteristics of the 

structures. 

DAMAGE TO ROADWAYS 

About 88 miles of roadway in 

south-central Alaska required replacement or relocation, 'but ap-· 

proximately 186 miles of roadway 

were affected in one manner or another by the earthquake. This total 

consists of 45 miles on the Copper 

River Highway, 35 miles on the 

Sew~trd-Anchorage Highway, 40 

miles on the Richardson Highway, 

approximately 16 miles on the 

Glenn Highway,_ 18 miles on the 

Kodiak Island road system., 11 

miles on the Sterling Highway 

(including Homer Split), and 7 

miles on the Portage Glacier Road. 

The remaining 10 miles of damaged roadway were on secondary 

roads. 

The 88 miles of roadway that required replacement or relocation is 

considered seJvere damage in this 

report. Of the 88 miles, 30 were on 

the Copper River Highway, 25 on 

the Seward-.Apchorage Highway, 

5 on the Sterling Highway, 5 on 

the Richardson Highway, 2 on the 

Glenn Highway, 2 on Point Whitshed Road, 1 on Portage Glacier 

Road, and 18 miles on the l{odiak 

Island road system. 

Figures 2-7 show the type and 

location of the damage on the 

major highways in south-central 

Alaska. A correlation between 

foundation material of the Seward-Anchorage, Sterling, Glenn, 

and Richardson Highways and 

damage sustained is shown on 

tables 3-6 (p. C53, C54). 
so·-

EFFECTS ON THE HIGHWAY SYSTEM 

151° 

..... 

~ 

~ 

4./ ~ 

~ ~~ 

..f 

10 20 MILES 

150" 

EXPLANATION 

DAMAGE TO ROADWAY 

Highway 

Dashed line indicates 

roadway that required 

replacement or relocation 

A 

Avalanches 

c 

Roadway compacted 

D 

Roadway displaced 

F 

Roadway fractured 

s 

Landslides 

w 

Roadway wavy 

DAMAGE TO BRIDGES 

0 

None 

<D 

Slight 

Moderate 

• 

Severe to destroyed 

25 

==='== 

Milepost 

C5 

2.-Routes of Sterling Highway and part of Seward-Anchorage Highway, and effects of the earthquake upon the highways. 
C6 

150° 

61°00' 

- 59°45' 

ALASKA EARTHQUAKE, MARCH 27, 1964 

149° 30' 149° 

EXPLANATION 

DAMAGE TO ROADWAY 

==== 

Highway 

Dashed line indicates 

roadway that required 

replacement or relocation 

A 

Avalanches 

c 

Roadway compacted 

D 

Roadway displaced 

--...........__ 

h 

F 

Roadway fractured 

I 

Roadway inundated 

iluring high tide 

c 

s 

Landslide 

w 

Roadway wavy 

0 

h 

0 

DAMAGE TO BRIDGES 

0 

None 

<D 

Slight 

ED 

Moderate 

Severe to • destroyed 

55 

Milepost 

10 MILES 

t 

s 

PORTAGE 

GLACIER 

ROAD 

3.-Routes of part of Seward-Anchorage Highway, the Hope Road, the Portage Glacier Road, and effects of the earthquake 

upon the highways. 
150" 

62" 

61" 

EFFEC'DS ON THE HIGHWAY SYSTE·M 

149" 148" 14 7" 

c 0 p Talkeetna 

Mountains 

c h u g a c h 

0 10 

EXPLANATION 

DAMAGE TO ROADWAY 

Highway 

Dashed line indicates 

roadway that required 

replacement or relocation 

A 

Avalanche 

c 

Roadway compacted 

F 

Roadway fractured 

I 

Roadway inundated 

during high tide 

s 

Landslide 

w 

Roadway wavy 

M 0 u n 

20 30 MILES 

DAMAGE TO BRIDGES 

0 

None 

(J) 

Slight 

Severe to • destroyed 

140 _____.__ 

Milepost 

146" 

t a 

4:.:_Route of Glenn Highway and effects of the earthquake upon the highway. 

C7 

145" 
C8 

62" 

61° 

0 

ALASKA EARTHQUAKE, MARCH 27, 1964 

146" 

E R R V E R 

LOWLAND 

EXPLANATION 

DAMAGE TO ROADWAY 

Highway 

Dashed line indicates 

roadway that required 

replacement or relocation 

A 

Avalanche 

c 

Roadway compacted 

D 

Roadway displaced 

E 

Roadway eroded 

F 

Roadway fractured 

s 

Landslide 

w 

Roadway wavy 

10 

DAMAGE TO BRIDGES 

0 

None 

<D 

Slight 

e 

Moderate 

• Severe to destroyed 

~ 

85 

Milepost 

20 MILES 

,.., 5 

145" 

5.-Routes of the Edgerton Highway and part of the Richardson Highway, and effects of the earthquake on the highways. 
60"30' 

EFFEC'DS ON THE HIGHWAY SYSTEM 

145"30' 

h u g a c h 

145"00' 

M o u n t a 

.From mile 6 to 51 on Copper 

River Highway, roadway 

was fractured, compacted, 

displaced and wavy 

EXPLANATION 

DAMAGE TO 

ROADWAY 

===== 

Highway 

/)(tshed line indica.tes 

rortrlturty thrtt required 

replucement O'l' ·relocution 

25 

==!:::: 

Milepost 

DAMAGE TO BRIDGES 

0 

None 

<D 

Slight 

EB 

Moderate 

Severe to • destroyed 

0 8 12 MILES 

n s 

6.-Routes of Copper River Highway and Point Whitshed Road, and effects of the earthquake upon the highways. 

C9 
ClO 

57"45' 

I 

57"30' 

0 

() 

ALASKA EARTHQUAKE, MARCH 2.7, 1964 

152"30' 

N I A K 

A y 

EXPLANATION 

DAMAGE TO SRI DGES 

0 

None 

Bridges destroyed • by 

seismic sea waves 

e 

Bridges replaced due 

to regional and local 

subsidence 

DAMAGE TO ROADWAY 

Highway 

Dashed line indicates 

roadway that required 

replacement or relocation 

c 

Roadway compacted 

E 

Roadway eroded 

I 

Roadway inundated 

during high tide 

Ss 

Roadway inundated by 

seismic sea waves 

25 

:=::!::: 

Milepost 

Cape 

Grevllle 

GULF 0 F 

ALASKA 

0 4 6 MILES 

7.-Highway routes on Kodiak Island and effects of the earthquake upon the highways. 
The earthquake damaged the 

roadwnys chiefly by (1) seismic 

shaking, (2) compaction of the 

roadway fill as well as the underlying sediments, ( 3) lateral displacement of the roadway and 

underlying sediments, ( 4) fractures in the roadway, especially on 

the paved surfaces, ( 5) landslides 

onto the roadway and of the roadway itself, (6) avalanches upon 

the roadway, (7) inundation and 

erosion of the roadway by seismic 

sea waves, (8) inundation by the 

sea of the .roadway along lowlying coa.stal nreas because of regional subsidence and differential 

compaction of the highway, and 

(9) differential compaction of 

roadway which caused a wavy effect. Much of this damage can be 

directly correlated with the geologic environment of the roadway. 

The damage by seismic sea waves 

was due, of course, not to the geologic conditions but to the proximity to the open sea. 

The most severe damage to roadways occurred at Snow River 

Crossing (fig. 2) and from mile 

75.1 to about mile 90 (fig. 3) on the 

Seward-Anchorage :Highway, on 

the Copper River I:Iighway (fig. 

6) , and from mile 1 to mile 5 on 

the Richardson I:Iighway (fig. 5). 

The Snow R.iver Crossing is underlnin by nonplastic silt and sand 

(fig. 8 ; table 7, p. C55). H~re the 

groundwater table is generally 

within 1 foot of the surface. The 

Turnagain Al'ln section of the 

Seward - Anchorage Highway 

(mile 75.1 to mile 90) is primarily 

underlain by silt and sand with 

minor ·amounts of gravel (fig. 9). 

The sediments are nonplastic,, 

(ta.bles 8, 9, p. 055, C56). Although not indicated on the 

grn.phic logs of the test holes, the 

water table lies generally within 

3 feet of the surface; in the vicinity of the town of Portage the 

281-012 0--68-3 

EFFEC'l'S ON THE HIGHWAY SYSTEM 

water table is within 2 feet of the 

surface. 

Mile 17.3 Mile 17.5 Mile 17.6 Mile 17.6 

Elev 438.5 ft Elev 438.5 ft Elev 436 ft Elev 435.5 ft 

GWS 437.0 ft GWS 437.0 ft GWS 436ft GWS 437 0 ft 0 

10 

20 

- Sand fill -

... 

Organic Gravel till Fine gravel 

Fine Fine 

1- silt gravel [;Medium _ gravel 

Pebbly Pebbly and sand sand 

sand sand Pebbly 

1- Sand sand - Sand Fine sand Fine 

and silt sand 30 1- lenses - !-Very 

fine ,_ 40 .... 

.... 

~ 50 

;5 

e; 

c 60 

Sand 1- Silt sand - Fine sand and and silt fine 1- lenses sand - Silt, sand 

and organ· Silt 1- ic material - Silt and 

fine sand 

70 1- Fine Silt and - sand sand lenses Silt 

80 Silt 

Medium - sand Silty 

90 1- Silt and sand sand - Silt GWS =Ground-water 

surface 100 

8.-Graphic logs of test holes at Snow 

River Crossing on Seward-Anchorage 

Highway. Logged by Alaska Department 

of Highways. 

The Copper River Highway is 

also underlain by nonplastic sediments consisting primarily of silt, 

sand, and sandy gravel (fig. 10; 

table 10, p. 056). The water table 

lies within 6 feet of the surface between mile 5 and mile 18 and 

locally is within 1 foot of the surface. Within a few feet of the 

surface, much of the underlying 

sediments contain organic material. This material leaves much 

to be desired as road foundation 

because it will compact when fill is 

placed upon it or will subside or 

compact differentially when subjected to seismic shaking. 

The Richardson Highway road· 

way was most severely damaged on 

n~nplastic glacial outwash sediments consisting of sandy gravel 

and minor amounts of silt (fig. 11; 

table 11, p. C56). The water table 

lies within 10 feet of the ground 

upon which the road fill was first 

placed. At mile 2.1 the water table 

is within 1 foot of the surface, at 

mile 2.56 within 3 feet of the 

surface. 

Cll 

FRACTURES 

The seismic shock of the earthquake fractured the roadways of 

all the major highways in the 

south -central part of the Alaska 

mainland, but no fractures were 

observed on the Kodiak Island system except for those noted on 

paved streets on the Kodiak Naval 

Station about 6 miles south of 

Kodiak. This does not necessarily 

mean that the seismic shaking did 

not develop any fractures, but 

rather that they were not visible 

during our study in the summer of 

1964. Nor were any fractures visible in the low-lying coastal areas 

where they may have developed 

either they did not exist or they. 

were not visible at the time of this 

study; repeated postearthquake . 

inundation and scouring by the sea 

may well have destroyed the fractures or eroded the roadway away 

completely. At the time of the 

Alaska earthquake, the Glenn 

Highway was unpaved from about 

mile 55 to Glennallen. Roadwork 

was underway in most of this 

stretch of the highway during the 

summer of 1964; this roadwork obviously destroyed any fractures in 

the roadway. The most reliable indications of earthquake-generated 

fractures were on paved roads, and 

some of the fractures there had to 

be examined carefully to determine 

whether they were pre- or postearthquake; 

Not including fractures due to 

landslides, the Alaska earthquake 

generated at least five major fracture patterns on the Alaska roadways (fig. 12). Fractures formed 

(1) normal to the roadway, (2) 

along 'the center of the roadway, 

( 3) on the shoulders parallel to 

the roadway, (4) as oblique fractures on original ground, then refracted normal to the roadway, 

and, once across the roadway, 

again dblique to it, and ( 5). oblique 
Cl2 

30 

20 

10 

-10 

-20 

-30 

-40 

-50 

-60 

-70 

-80 

-90 

Placer River 

Mile 78.4 

26.9 - .-

Silty sandy g ravel 

l!Siightly camp acted silty 

sandy gravel 

1 I 11 /4o I 

Compacted sil ty gravel, sand 

2)35)60) 

3159\601 

!,-Dense to very dense 

silty sand 

5 \1031 75 I 

Dense to very dense 

clayey silt 

1 I 11 J9o I Dense sandy silt with trace of clay 

8 I 68 l1oo I 

Twentymile River 

ALASKA EARTHQUAKE, MARCH 27, 1964 

Portage Creek 1 

Mile 79 

27 .-

Fill 

1 /4s /5o I 

Slightly camp acted sandy silt 

2 113 I 3 I 

3 I 30 I 75 I Dense to very dense silty sand 

with traces o f fine gravel 

4 l8ols41 

5 I 44 I 1 I 

6 /130/95/ 

1 I 37 I 90 I 

8 1140 l1ool 

Dense to very 

silt with trace 

dense sandy 

s of clay 

Portage Creek 2 

Mile 79.6 

25 rFill 

Slightly camp acted sandy gravel 

1 111 I 5o I 

Slightly camp 

2 115 I 5o I 

31281601 

4\64\80\ 

5)65)50) 

6158\351 

Compacted pi 

7 /24 /_95J 

acted lenses of sand and silt 

Compacted to dense 

fine sand with 

lenses and layers 

of fine gravel 

Dense fine sandy 

silt with wood 

fragments and 

organic material 

astic silt 

EXPLANATION 

Grad t' I contact 

5 

Sample number 

Blows per toot 

Percent recovery 

30 Mile 80.8 

Peterson Creek 

Mile 84.2 

Kern Creek 

Mile 86.6 

26 

Blows per foot: 140-lb 

hammer with 30-in. 

drop 

20 

10 

-10 0 

-20 

> -30 

-40 

-50 

-60 

-70 

-60 

17 -

Silty sand 

I 114 I 40 I 

Slightly camp acted to compacted 

silty sandy gr a vel 

2 I 26 I 95 I 

3 I 33 I 75 I 

Compacted I o dense silty 

sand with gra vel 

4 I 36 I 35 I 

5 /92 1 35 1 

26 

Sl ightly compacted to very dense silty 

sand with traces and lenses of clay 

- -

Fill: Sandy gr a vel 

1 I 8 115 I Loose to den se sandy gravel 

with traces of silt 

3 I 29 I 45 I 

5 /41 I so I 

1 I s9 I 75 I 

814sT8o 

9 I • I 10 I 

10 I 36 I 10 I 

Dense to very dense layers 

of silt and sandy gravel 

- - Fill: Sandy gr a vel 

1 115 110·1 

Compacted to very dense silty 

gravel with tr ace of sand 

3 I s1 I 35 I 

5 I 63 I 60 I' 

Dense to very 

silty sandy gr 

6 /93 /_ I 

dense 

a vel 

s /18 /10o I c 

n I 21 I 25/ 

ompacted to dense silt with gravel 

lenses and traces of sand and clay 

7 I 55 11001 

8 I 34 1100 I 

Virgin Creek 

Mile 89.6 

27 

Fill: Silty sandy gravel 

Silty sand with 

organic material 

Silty clayey sand with 

trace of organic material 

Silty sand with 

gravel and cobbles 

12 I 35 I 60 I 

Glacier Creek 

Mile 90.0 

27 - -

Fill: Silty san dy 

gravel and c obbles 

1 I 21/ 3sl 

2 I 20 115 I 

Slightly camp acted to very 

dense siltv sa ndy gravel 

4 I 8sl 53 I 

6 114 I 451 

s 

1 I 10 I 5o I 

8 I • T 75l 

Very dense si 

lightly compacted 

to dense silty sand 

with traces of 

gravel and clay 

with occasion 

lty sandy gravel 

al cobble 

9 11021 so I 

Tidewake Slough 6 

Mile 90.9 

26 ' 

Fill: Silty sand y gravel 

Slightly compa cted 

vsilty sandy gra vel 

1 113 1 2o 1 

2 111 l8o 1 

4 J 4 1 75 J 

6 1 2211oo1 

7l35l8ol 

Compacted to 

sand with trac 

8/30/60j 

9 1 ss I 1s I 

Loose to slightly compacted 

silty clayey organic material 

Slightly compacted to compacted 

silty clay with sand and gravel 

dense silty clayey 

e of gravel 

*Indicates refusal or 100+ 

blows per foot 

9.-Grapbic logs of test holes ·at miles 78.4, 79.0, 79.6, 80.8, 84.2, 86.6, 89.6, 90.0, and 90.9, Seward-Anchorage Highway. 
ffi 

!: 

;i 

0 

;::: 

co: 

~ 

ffi 

!: 

;i 

0 

~ 

EFFECTS ON THE HIGHWAY SYSTEM C13 

50 

40 

30 

20 

10 

-10 

-20 

-30 

-40 

-so 

-60 

50 

40 GW s30 

20 

10 

-10 

-20 

-30 

-40 

-so 

-60 

Fill 

I I 9 I 60 I 

Silty sond wl 

motorlol ond 

th organic 

sondy silt 

2 I 35 I 1s I 

Silt with clay 

3 111 190 1 

\sandy silt, or 

motorlol, ond 

41201801 

gonic 

cloy 

Cloyoy silt wl th sandy 

silt ond c.rgo nlc motorlol 

5 116 1100 I 

Fino sondy sl 

orgonlc mote 

6l84lsol 

Fill 

40.3 

It ond 

rlnl 

Silty grovel s ond 

I 112 I 50 I 

Silty gravelly sand with 

traces of oru nlc motorial 

2 115_110 I 

Silty gravel w 

motorial ond 

lth organic 

sand 

Gravelly sand 

s J 24_160 1 

PebblY sond a 

4 IN 11001 

s j22j1ooj 

Clayey silt wit 

organic mater 

6 1 76 1 so 1 

nd silty gravel 

Silty aravol 

h traces of 

lei and sond 

Fino silty sand 

60 ~ 25 11 Ll t 

50 GWSTI Layers of sond, silty sand, ond 

organic material 

40 

Sundy gravel with soma slit 

30 ~ 

.!1 

i 

25 It Ll t. 

40 

lFIII ~ ~:~:: :::::: with somo slit 

30 Layers of sandy gravel ond sand with 

soma organic ma20 terlal 

10 

GWS 

GWS -

Fill 

f- 26.3 

Silty angular 

and organic 

gravel 

material 

I 118 I 20 I 

2 111 I 60 I 

Silty pebbly s and with 

organic mate rial and clay 

3j8oj10ol 

4 I 20 I 10 I 

Clayey silt wit h organic 

material and sand 

s -1 37 160 I 

6 1m12o I Very line sand 

1- 37.8 

Fill 

Graval with si 

I I 9 110 I 

Silty sandy gr 

organic mater 

2 I 11 I 45 I 

Sandy silt wit 

avol with 

ial 

organic mater ial 

3120-IIOO I 

Silty sand wit h 

organic claye y silt 

4 I 6 11001 

Clayey silt wit 

organic mater ial 

~ .. 

5 114 I 60 I 

Silty sand wit h organic 

material and clay 

6 j31 j8o I 

"' :e 

.. 

i 

On t 

t

Sandy gravel (fill) GWS 

Silty gravel with 

some sand 

i 

1511 Rt t 

GWS 

GWS 1

0rganic material 

Loose silty sand with some organic material 

Medium-dense sand with some layers 

of gravel; trace of organic material 

7 75 Sandy gravel with traces of 

· clayey silt and organic material 

Clayey silt with organic material. gravelly 

clayey silt. and traces of sand 

7 70 

Fino silty sand 

4 II 75 

Silty sand with clayey 

silt and organic material 

5 II 75 Fino silty sand 

50

~ O~nt Sandy gravel 

i!'i 40 · Fill Silty sand with 

z organic material 

g 30 Sandy gravel 

~ 20 

"' 

~ 

w~ ~ ,_ 

... 

... 40 It Rt il 

!: 50 WS ~s;"' ''~'1 

z Sand and silt 0 

;::: 40 

~ Sandy ·gravel 

30 

EXPLANATION 

Gradational ., contact 0 ~ 1 .E! 

., ~ ., c. c: ! "' ., ~ <> 

., (I) as "-

7 15 

Blows per foot: 140 -lb hammer 

with 30- in drop 

GWS=Ground-water surface 

.. 

i 

40 It Rt il 

25 It 

n Sandy gravel with u trace of silt 

00 

~ 

.. 

i 

Ll '-

oovs ~'''" Sandy """'' gravel mom;, Loose organic sand with 

some traces of organic 

silt and gravel; some wood 

0 rganic silt 

Sandy gravel 

40 ft Rt (or lf) (. =40 feet right (or left) of centerline of highway 

00 

:e 

.. 

i 

10 It Lit. 

GWS ~Sandy gravel (fill) 

Sandy gravel with some silt and some 

layers of sand 

"' 

~ 

.. 

i 

10 It Lit. 

~ Sandy gravel with some silt 

Fill 

Sandy silt and gravel with trace of 

or·ganic material 

"! 

22 

.. 

i 

10 It Ll t 

~''""' '""' ""' wmo oliO 

10.-Graphic logs of test holes at miles 7.6, 8.2, 9.2, 10.1, 11.0, 14.8, 15.1, 15.2, 15.8, 16.0, 16.5, 16.8, 17.2, 17.4, 18.2, and 18.6, 

Copper River Highway. 

l 

l 

l 
C14 ALASKA EARTHQUAKE, MARCH 27, 1964 

50 

Mile 0.70 Mile 0.88 Mile 1.28 Mile 1.52 Mile 1.73 

>-

t:j 40 D Sandy gravel, some silt D Sandy gravel, some silt i

Road fill: Sandy gravel, some silt 

~ Road fill: Sandy gravel, 

some silt 

Road fill: Sandy gravel, 

some silt 

z 30 0 

;:: 

~ 20 

10 

50 

40 

Mile 1.82 

Road fill: Sandy gravel, 

some silt Mile 2.08 

Sandy silt . some gravel 

GWS Sandy gravel 

some silt 

Sandy gravel. some silt 

and organic material 

GWS=Ground-water surface 

Sandy gravel, 

some silt 

GWS 

>-

.... 

30 

.... 20 

g 10 

~ 

Sandy gravel, 

sorrie silt i

Road fill: Sandy gravel, 

some silt 

Sandy gravel 

some silt 

Gravelly sand, 

GWS some silt 

Silty sand 

Gravelly sand 

Mile 2.31 

GWS 

Road fill: Sandy gravel, 

some silt 

Sandy .gravel, some silt 

with lenses of gravelly 

sand and silty sand 

Mile 2.56 

GWS 

Road fill: Sandy gravel, 

some silt 

Sandy gravel, 

some silt 

Mile 2.78 

GWS 

Road fill: Sandy gravel, some silt 

Gravelly sand. some silt 

Silty sand. some gravel 

-10 

-20 

-30 

11.-Graphic logs of te·st holes at miles 0.70, 0.82, 1.28, 1.52, 1.73, 1.82, 2.08, 2.56, and 2.73, Richardson Highway. Analysis 

by Alaska Department of Highways. 

to the roadway. Some stretches of 

roadway had morethan one fracture pattern. 

Much of the highway system 

was fractured by seismic shaking 

(figs. 2-7) . The ·most spectacular 

fractures occurred on the SewardAnchorage Highway from mile 

75.1 to mile 90, but extensive fracturing also occurred on the Richardson Highway between miles 0 

and 5, between miles 64 and 80, 

and on the Copper River Highway. 

The extent and nature of the fractures depended upon the type and 

thickness of the sediments and the 

depth to the water table. Fractures 

were conspicuous in swamp deposits and in thick accumulations 

of silt and sand, especially if the 

water table was within 6 feet of 

the ground surface. In general, the 

closer the water table was to the 

ground surface, the more extensive and varied the fracture patterns were. For example, at the 

southeast end of Turnagain Arm 

near Portage the Seward-Anchorage Highway passes over silt _and 

sand, and the water table is within 

2 feet of the ground surface. The 

fractures here were very extensive. 

The fractures on the highway 

were more pronounced than those 

on the roadbed of the railroad, but 

the railroad was displaced horizontally for ·about the same distance as the highway. 

There are several reasons why 

the fracture pattern is more pronounced on the highway than on 

the railroad. The highway roadway is generally constructed of 

well-graded (poo-rly sorted) compacted fill and is paved. In contrast, the railroad roadbed was 

originally constructed by using 

about 1 foot of ballast that consisted chiefly of coarse gravel. 

Over a period of years the railroad 

roadbed was raised to grade by 

adding coarse gravel, and thus the 

thickness of coarse poorly graded 

gravel is much greater than it was 

originally. When the earthquake 

struck the Portage area and the 

sediments were displaced, the denser highway roadway was easily 

fractured, whereas the coarse 

gravel of the railroad roadbed, although displaced, was not extensively fractured. 

As stated earlier, the most extensive fracturing occurred on the 

Seward-Anchorage Highway at 

the head of Turnagain Arm. Table 

12 (p. C57) shows the correlation 

of founda-tion material a,nd fractures from mile 75.1 (Ingram 

Creek) to mile 95.0. 

FRACTURES NORMAL TO THE HIGHWAY 

The most conspicuous fractures 

observed were those normal to the 

axis of. the roadway (figs. 12E, 

13) ; they were extensive along tl)e 

Seward-Anchorage Highway and 

on the Richardson, Sterling, and 

Glenn Highways, particularly in 

paved sections. These fractures, 

plus the oblique type shown on 

figure 12F (2), represent about 90 
EFFEC'DS ON THE HIGHWAY SYSTEM C15 

A B 

c D 

- E F 

12.-Scbematic drawing of types of fracture generated by earthquake in roadways. A, Preeartbquake. B, Underlying sediments compact and displace laterally. Roadway settles differentially and is moved laterally by underlying sediments ; 

roadway fract~1res along centerline and is wavy; hump is formed off roadway. 0, Underlying sediments compact and move 

laterally; roadway settles and longitudinal fractures develop along edges; roadway ·also wavy. D, Longitudinal fractures 

form as in 0,- as underlying sediments continue to compact and displace laterally, roadway settles differentially and 

transverse fractures develop. E, Fracture forms owing to horizontal displacement of roadway and underlying sediments; 

fracture generally originates off roadway. F, Fracture forms in original ground oblique to roadway; as it strikes roadway, 

it either continues at oblique ·angle (Fl) or is refracted normal to roadway and, when past roadway, becomes oblique again 

(F2) ; these fractures occur chiefly in small roadway fills. 
ALASKA EARTHQUAKE, MARCH 27, 1964 

13.-View northwest showing conspicuous centerline fracture and more typical 

perpendicular fractures on Seward-Anchorage Highway between Pol.tage and 

Twentymile River. Photograph by D. S. McCulloch. 
EFFECTS ON THE HIGHWAY SYSTEM C17 

14.-Centerline fracture on unpaved Copper River Highway at south approach of Clear Creek bridge 329 at mile 41.0. 

Photograph by George Plafker. 

percent of those observed on the 

Richardson, Glenn, ancl Sterling 

Highways and about 75 percent of 

those on the Seward-Anchorage 

Highway. 

From mile '75.1 to mile 91 and 

from mile 99 to mile 105 on the 

Seward-Anchorage High\\-ay, the 

fractures normal to the axis of the 

higl~~~*ay were spaced 75 to 200 feet 

apart. Horizontal clisplacement of 

as much as 5 feet and vertical displacement of 1 foot were noted. 

Where the highway passecl over 

fine-grained sediments and svanlp 

debris, such as the Sterling Highway near mile '71 and again near 

mile 75, the roadway \\-as skewed 

and displaced as much as 4 feet 

horizontally and 8 to 10 inches 

vertically, and the spacing of the 

fractures was as close as 10 feet. 

FRACTURES ALONG HIGHWAY 

CENTERLINE 

Fractures along the centerline 

of the highway (fig. 12B) formed 

near Portage on the Seward-Anchorage Highway (fig. 13) and on 

the uilpavecl Copper River Highway, especially from mile 40 to the 

Million Dollar bridge (fig. 14). 

This type of fracture occurred (1) 

where a relatively thick roadway 

fill was underlain by fine-grained 

saturated sediillents in swamp 

deposits, and (2) ~rhere the roadway vas underlain by fine-gi-ainecl 

silty sand ancl gravel and the 

water table was within 2 feet of 

the surface. Most of the axe3 of the 

fractures on the centerline of the 

highway were normal or nearly 

normal to the direction of seismic 

motion. The centerline fractures 

along the Portage and Copper 

River Highways are perpendicullar to the slope of terrain. 

The largest centerline fracture 

occurred between Portage and 

Twentymile River on the SewardAnchorage Highway (fig. 13). The 

fracture \ms about 500 feet long, 

as much as 10 feet wide, ancl6 to 8 

feet deep. 

FRACTURES ALONG HIGHWAY EDGE 

Fractures formed locally along 

the edges of all the llighways. This 

type of fracture (fig. 126') was 

responsible for conside~able damage, especially on the Copper 

River Highway and the SemardAnchorage Highway near mile 
C18 ALASKA EARTHQUAKE, MARCH 2 7, 19 64 

75.0. Because of the differential 

settling of the roadway associated 

with this fracture pattern, the 

roadway is wavy. 

FRACTURES NORMAL TO AND ALONG 

HIGHWAY EDGE 

On the Copper River Highway 

severe fracturing occurred along 

the edges of the roadn~ay (fig. 15) 

as well as normal to the roadway, 

primarily in the roadway fill (fig. 

120). The fractures shown on 

figure 15 were in a fill 8 to 10 feet 

thick which subsided about 3 feet 

into the underlying fine sand and 

silt desposited by the Copper 

River. The waviness of the roadway shown on figure 15 indicates 

differential compaction 'and lateral displacement of khe underlying sediments. 

OBLIQUE FRACTURES 

Oblique fractures, an interesting 

but not commonly destructive 

fracture system, occurred during 

the earthquake (fig. 12F). These 

fractures originate on the ground 

off the highway fill and intersect 

the shoulders of the fill at oblique 

angles. Some continue through the 

fill at the same angle and into the 

ground again (fig. 1227 (1) ) . More 

commonly, however, where the 

fracture strikes the roadway it is 

refracted normal to the roadway 

axis. Once through the roadway, 

the fractures once again become 

oblique and attain their original 

heading (fig. 12F(2)). Th' is refracted fracture is especially common where the roadway is paved. 

Such fractures occurred on the 

road at the north end of Hood 

Lake in Anchorage, on parts of 

the Richardson Highway, on the 

Copper River flats, and on the 

Seward-Anc1~or;ige Highway a 

few miles soutlz of Anchorage. 

I)isplacement, both vertical ancl 

horizontal, is very slight and thus 

is not very destructive. 

15.-Fractures normal to and along highway edge, Copper River Highway. Looking 

east from Capper River bridge 2, mile 2'7.1. Approach ~ubsided 3 feet and fractured. 

COMPLEX FRACTURES 

Where the highway passed over 

saturated fine sand and silt with 

a free face close by, a very distinct 

and destructive fracture system 

developecl (fig. 16). The fractures 

of this system have horizontal displacements of as much as 2 feet 

and vertical displacements of 18 

inches. Figure 16 shows that lateral displace~nents and slumping 

to~vard a frec face occurred with 

inovement to the right. Fractures 

normal to the roaclway near the 

lllleil River indicate that the sedinlents also nloved toward the 

river, although this movement is 

not clear on the illustration. In 

addition, the ullderlying supporting sediments failed. 

ORIGIN OF FRACTURES 

At the time of the earthquake, 

much of the roadway and ground 

beneath it was frozen to depths of 

4 to 5 feet. A frozen roadway is 

more brittle than a thawed roadway, but the frozen ground probably did not play a major role in 

the origin of a fracture; however, 

once the fracture developed in a 

frozen roadway, it maintained its 

integrity. 

NORMAL TO HIGHWAY 

Fractures normal to the road11-ay are due to shear and tension 

(fig. 1212'). The fractures due to 

shear first form in the grou~id because of mass displacement of the 

underlying sediments toward a 
EFFECTS ON THE HIGHWAY SYSTEM 

free face. The lateral displacement 

is general, and the roadway does 

not show the total horizontal displacement in one fracture but in a 

series of them; thus, the roadway 

when viewed in plan is askew. At 

the same time, differential compadion and lateral displacement 

of the underlying sediments parallel to the axis of the roadway 

cause tension and vertical as well 

as horizontal displacements. 

ALONG HIGHWAY CENTERLINE 

Failures along the centerline of 

the highway fill are due to tension 

(fig. 1223). As the roadway and 

underlying sediments are subjected ,to seismic shaking, the 

denser roadway subsides into the 

underlying less-dense sediments. 

The sediments then flow outward 

and the overlying fill fails. The 

underlying sediments are not necessarily liquefied; failure can occur prior to liquefaction. There is 

generally a hump or fracture on 

the original ground where the 

compacted and laterally displaced 

underlying sediments flow toward 

the surface. Intense seismic shaking of relatively long duration is 

necessary to produce centerline 

fractures. Eyewitness accounts indicate that such shaking did indeed occur in the Portage and 

Copper River areas. 

NORMAL TO AND ALONG HIGHWAY EDGE 

Fractures along the edges and 

parallel to the roadway (fig. 12C, 

D) are caused by compaction of 

the underlying sediments and lateral spreading of the ground. As 

seen in figure 12C the roadway, 

although wavy from differential 

compaction, has maintained its integrity. As the roadway is subsiding differentially, it is also being 

displaced along the axis owing to 

displacement of the underlying 

sediment. Thus, normal and longitudinal fractures are due to tension and are confined to the road 

fill. 

SUBSIDENCE OF ROADWAY 

Throughout south-central Alaska the highway system experienced much local subsidence because of compaction and lateral 

displacement of the underlying 

16.-Complex fractures with relatively large lateral and vertical displacements, produced by movement of saturated fine sand 

and silt toward free faces. View north near mile 58.5, Copper River Highway. The Allen River, which drains Allen Glacier, 

is in the background. 
C20 

s~diments. Although not as spectacular as the damage from fractures, this damage was the most 

widespread. The only places that 

escaped were those where the roadway was on bedrock. The local differential subsidence made the 

roadways undulating and wavy 

and dropped the approaches to 

most of the bridges. 

The most spectacular looal subsidence occurred ( 1) on the Richardson Highwa.y between mile 0.0 

and mile 5.0, (2) on the Copper 

River Highway near mile 28.0, and 

(3) on the Seward-Anchorage 

Highway at Snow River Crossing 

and from mile 75.1 to mile 91.0. 

Figure 17 shows pre- and postearthquake profiles from mile 0.7 

to mile 2.5 of the Richardson 

Highway; figure 18, pre- and postearthquake profiles from mile 5.9 

to mile 11.0 of the Copper River 

Highwa~; figure 19, pre- and postearthquake profiles from mile 75.1 

to mile 85.0 of the SewardAnchorage Highway; and figure 

20, pre- and postearthquake profiles and pier elevations at the 

Snow River Crossing of the Seward-Anchorage Highway. 

None of the post:€arthquake profiles indicate tectonic subsidence 

or uplift; they represent only subsidence of the roadway due to compaction and Jateral displacement 

of the underlying sediments. A 

few profiles indicate uplift due to 

bulldozing of sediments against 

bridge abutments or to ground 

waves. Bulldozing occurs when the 

laterally displaced sediments of 

the bridge approaches strike the 

resisting bridge abutments and 

form a mound of sediments at the 

contact between the two. 

Another type of subsidence was 

noted at Snow River. At the time 

of the earthquake, the Alaska Department of Highways was constructing a second crossing there. 

ALASKA ,EARTHQUAKE, MARCH 2 7, 1·9 6 4 

50' 

45' ---------......__ __ 40' 

35' 

30'J_--------------------------------------------------------~ 

35~ Ill 

~ .. N 

30~ 

25' 

0 500 FEET 

EXPLANATION 

Preearthquake 

elevation 

Postearthquake 

elevation 

HORIZONTAL SCALE 

17.-Pre- and postearthquake profiles from mile 0.7 to mile 2.5, Richardson Highway. Data from Alaska Department of Highways. 

The piers shown on figures 20 and 

21, which are part of the new crossing and which subsided as much 

as 4 feet, rest on 18-inch tubular 

piles driven to depths of as much 

as 160 feet. The subsidence of these 

piers indicates that the under lying 

sediments either compacted to 

great depths or that seismic shaking in fine silt liquefied the sediments and allowed the piles to 

sink. In addition, when the piles 

at abutment 1 (fig. 20) were pulled, 

they were found to be distorted 

and bent by the earthquake below 

the ground surface. 

The roadway fill at the Snow 

River Crossing prior to the earthquake was; from 4 to 7 feet thick. 

After the earthquake the 4-foot 

part of the fill had subsided as 

much as 2 feet beneath the ground 

surface. The profile in · figure 20 

indicates that the ground surface 

subsided about 5 feet. Thus, in 

places the roadway must have subsided •as much as 11 feet, that is, 

the 4-foot fill subsided 6 feet and 

the sediments subsided 5 feet. This 

is the maximum recorded local 

subsidence due to compaction and 

displacement of the underlying 

sediment. Figure L 22 shows the 

western bridge at the crossing; the 

road fill here had to be almost 

completely replaced. 

The Snow River Crossing is underlain by fine sand and silt, covered with a thin veneer of fine 

gravel (fig. 8). The water table is 

in many cases at or within a foot 

of the surface. The fine-grained 

saturated sediments had very little 

strength, and, when the seismic 

shaking struck the area, the sediments failed primarily by liquefaction and lateral spreading or displacement. 

A large amount of local subsidence of the roadway occurred in 

the Portage area on the SewardAnchorage Highway. Here a maximum subsidence of 54 inches was 

measured by the Alaska DepartInent of Highways at mile 79.3 be~ 

tween Portage Creek 1 and 
EFFECTS ON THE HIGHWAY SYSTEM 

Milo 5.9 

::e===:- 20'--~~-------c~"------------------- --....... ,// -------i 15' ~-------------------------------------------------------------------L 

::. ~Lr ---====== ==-=-"-~,...:.==.=.::~ 20'~------------------------------------------------------------------~ 

35' 

30' 

25' 

/-, ,.... ______ ,.,... / I I J I 

v 

Scott 

20'J-----------------------------------------------------------------~ 

35' 

30' 

25' 

Scot.t 

{"'-------

\ ..1 v 

Scott 

Glacier 4 

---, r---

11 

Mil&"8.9 

u 20' -L---------------------------------------~------------------------~ 

Mile 8.9 

50' 

45' 

40' 

35' 

Scott 

Glacier 5 

' r-......- \ I 

v 30' J-------------------------------------------------------------------~ 

50' 

45' 

40' 

Scott 

Glacier 8 

35' J_----------------------------------------------------------------------~ 

45' 

35' -

Mile 11.0 

r 

30'J_------------------------------------------------------------------~ 

0 500 FEET 

HORIZONTAL SCALE 

EXPLANATION 

Preearthquake 

elevation 

Postearthquake 

elevation 

18.-Pre- nnd postearthquake profiles from mile 5.9 to mile 11.0, Copper River Highway. Data 

from Alaska Department of Highways. 

····· 

C21 
EFFECTS' ON THE HIGHWAY SYSTEM 

35' 

30' 

25' 

20'~--~-----------------------------------------------------------------L 

35' 

_,_-., r---- 30' -- I Twentymile River I 

I I -------- 25' I I 

I I 

\ ) '- ,....r.r 

\ I 

20' 

15' 

\.I 10' ~--------------------------------------------------------------------~ 

35'-

- 30'-

25'-

20'~--------------------------------------------------------------------~ 

~ 00 

3n·l~ I ~~-----------------~~--~~,·-· ~~~~-~~~==~~~· 25' ~- .......------------ ---- '-.../ _I 

~l r ~----~~-----------------------------------------------------~ 25' L 

~- --------------......_.....---.....,..........,..,...-----, ,.......,.....-.......,-----l 

35' 

30' 

25' 

20'~------------------------------------------------------------~------~ 

0 

.n 

00 

30~ ~......... ... ...... sc:::: --............_ 7 .-- <~; ~~ 25' -· '~--...... ----"' 

20'~----------------------------------------------------------------------~ 

19. (Above and left)-Pre- and postearthquake profiles from mile 75.1 to mile 85.0, 

Seward-Anchorage H;ighway. I{ata from Alaska Department of Highways. 

C23 
C'22 ALASKA EARTHQUAKE, MARCH 2 7, 1,9 64 

EXPLANATION 

Preearthquake 

elevation 

---- 

Postearthquake 

elevation 

,--. ., ' ' 

Bridge 

( Postearthquake) 

0 500 FEE1 

i--A 

HORIZONTAL SCALE 
C24 ALASKA EARTHQUAKE, MARCH 2 7, 19 64 

I Before earthquake 

After earthquake 

North side 

1 :::::: , z::: ::i: : I South s~de 444 18 442.17 443.33 443 43 

-- 

The original elevatlon on these columns was plus or mlnus 0.05 feet 

A 

ELEVATION OF TOP 

OF PIER. IN FEET 

EXPLANATION r 

---------- 

Preearthquake 

PIER 3 

This pier 15 

canted 34 ~n 

per ft S 

in per ft E 

--------__----_ Postearthquake ---_--___ --_---_ --____ \ -___--- . .- _--* 

1 0 500 1000 FEET I 

PIER 5 

Thls pler 1s 

canted1%- ~n 

per ft S $4 ~n 

per ft W 

20.-Pre- and postearthquake pier elevatiom (A) and profiles (B) near mile 17.3 at Snow River Crossing, Senyard-Anchorage 

Highway. Profilw are lat mt sih of Snow River Crming. Data supplied by Alaska Department of Highways. 

I 

21.-Bridge pier for new crossing at Snow River displaced by compaction of underlying sediments or by liquefaction of fine silts. Photograph by D. S. McCulloch. 

-- 

PIER 6 

Thls pler IS 

canted i ~n 

PIER 7 

Th~s pier IS 

cantedK3!n 

per ft S per ft w '?& 1% In per ft W In per tt S 
EFFECTS ON THE HIGHWAY SYSTEM 

22.-View, looking west, of arched bridge at Snow River Crossing. Note that new 

All in foreground was added to compensate for subsidence of approach fills and 

arching of bridge. Some of the original road fill had to be completely replaced. 

Photograph by D. S. McOulloch. 

Portage Creek 2 and at mile 82.1, 

0.1 mile north of Tidewater Slough 

5 bridge (fig. 19). Much subsidence also occurred in the finer 

grained sediments around Turnagain Arm. At mile 79.3 the roadway is underlain chiefly by silty 

sand deposited by Portage Creek, 

and at mile 82.1 the roadway is 

underlain predominantly by silt 

and sand. 

Local subsidence of the roadway 

fill caused uptilting of culverts in 

places on the Portage Glacier 

R o a d , the Seward-Anchorage 

Highway, and the Richardson 

Highway. 

In the Portage area on the Seward-Anchorage Highway there 

is a definite correlation between 

local subsidence of roadway, type 

of sediments, and thickness of the 

roadway fill (compare fig. 9 with 

fig. 19). The coarser the underlying sediments, the less the roadway 

subsided; the thicker the roadway 

fill, the more the roadway subsided. Another very important factor is the location of the water 

table; the closer the water table 

was to the surface, the more the 

roadway subsided and the more 

the underlying sediments moved 

laterally from beneath the roadway fill. 

The Richardson High~~ay betn-een mile 0.7 and mile 2.5 is 

underlain chiefly by sandy gravel, 

and the maximum local subsidence 

of the roadway was 85 inches 

(compare fig. 11 wit11 fig. 17). The 

water table generally is more than 

ti feet below the ground surface. 

Pre- and postearthquake profiles 

for the Copper River Highway are 

only available from mile 5.9 to 

mile 13. In this stretch of the highway a maximum local subsidence 

of 48 inches occurred at about mile 

7.6. Here the roadway is underlain 

by clay, silt, sand, and organic 

debris (fig. 10). At mile 10.1, 

where the roadway is underlain by 

silty gravelly sand and silty 

gravel, it did not subside. There 

was about 18 inches of subsidence 

at mile 11.0 where the high~vay is 

underlain chiefly by silty sandy 

gravel, sandy silt, and silty sand 

(all containing organic material; 

fig. 10) ; the water table there is 

about 2 feet from the surface. 

The Chiniak Highway on 

Kodiak Island also failed because 

of compaction and lateral displacement of the underlying unconsoliclated deposits. Maximum 

local subsidellce occurred at the 

heads of Womens Bay, Middle 

Ray, and Kalsin Bay. The amount 

of subsidence mas not measured 

but is estimated to be from 3 to 4 

feet at T;IJomens Bay and Middle 

Ray and 3 feet at Kalsin Bay. 

717llerever a higll~vay passes 

from fill to bedrock, there 11-as 

settlement of the fill because of 

seismic shaking. Commonly, the 

s~tbsidence is very pronounced and 

may even be expressed as a frac- 
C26 ALASKA EARTHQUAKE, MARCH 27, 1.9 64 

ture at or near the bedrock-sediment contact. Roadway-fill approaches to the bedrock outcrop at 

Bird Point on the Seward-Anchorage Highway settled 2% to 3 feet. 

The pavement on both sides of the 

bedrock outcrop is fractured, but 

the vertical displacement on each 

individual fracture is less than 2 

inches. In contrast, on the SewardAnchorage Highway near Ingram 

Creek (fig. 23), a single fracture 

was noted betn-een bedrock and 

sediments along which 22 inches of 

vertical displacement took place. 

LATERAL DISPLACEMENT OF 

ROADWAY 

Severe seismic shaking caused 

downslope lateral displacement of 

some sediments and the roadway 

resting on them. The maximum 

horizontal displacement measured 

on roadways was 13% feet at Snow 

River Crossing on the SewardAnchorage Highway. The horizontal displacement at Snow River 

as well as elsewhere was differential. 

The maximum measured horizontal displacement on the Richardson Highway \\-as 5.3 feet at 

about mile 1.6. 

The amount of horizontal displacement in the Portage area of 

the Seward-Anchorage Highway 

is unknown, but the railroad in 

this area was displaced about 10 

feet (David McCnlloch, oral commun., 1966), 70 it is not unreasonable to assume that the highwaj 

was displaced a similar distance. 

LANDSLIDES 

The earthquake triggered numerous small roadw-ay landslides : 

the locations of slides are sho~vn 

on figures 2-5. Most were small 

and only affected part of the roadway; on the Seward-Anchorage 

Highway near mile 44.5, for instance, about 100 feet of the road23.-Vertical displacement of roadway southeast of Ingram Creek on the SewardAnchorage Highway. Pavement in foregound is underlain by sediments; in background, by bedrock. Trench shovel handle is 10 inches long. Photographs by Helen 

Foster. 

way was displaced toward Summit 

Lake (fig. 24). There were also 

several small landslides between 

mile 54 and mile 56 on the SewardAnchorage Highway. 

The only relatively destructive 

landslides on the Sterling Highway were near Cooper Landing 

and at mile 60.5. On the Glenn 

Highway there were 10 slides; 

these occurred near mile 30, at 

Moose River, mile 61, mile 69, mile 

70, at both approaches to Caribou 

Creek at mile 106.9, mile 139, and 

mile 140. The most destructive of 

these slides were at Caribou Creek. 

The slides that caused the most 

damage were on the Richardson 

Higl~way at mile 65 and at the 

bridge crossing the Little Tonsina 

River. The landslide compressed 

the bridge and left a 3- to 4-foot 

hump where the asphalt paving 

meets the bulkhead. 
EFFECTS ON THE HIGHWAY SYSTEM 

A much larger landslide was 

generated in glacial debris at mile 

72.5 on the Richardson Highway 

where about 300 feet of the roadway was displaced about 7 inches 

downslope. 

AVALANCHES 

The numerous avalanches generated by the earthquake caused 

only minor damage to the highway 

system in south-central Alaska. 

Most of the avalanches that caused 

highway damage occurred on the 

Seward-Anchorage Highway between mile 83 and mile 95; here 

the largest covered the roadway 

with at least 20 feet of snow. 

Large avalanches occurred at 

miles 38, 39, and 42 in the rugged 

terrain of the Chugach Mountains 

through which the Richardson 

Highway passes. At mile 44, a rock 

slide developed. Although not on 

the roadway, a large avalanche 

near mile 50 dammed the Tiekel 

River and had to be removed by 

explosives because the rising 

waters were endangering the highway. A 200-foot landslide on the 

Edgerton Highway at Lower 

Tonsina Hill, a short distance 

north of Lower Tonsina, was 

noted by Ferrians (1966). 

SAND EJECTA BLANKETS 

Formation of sand ejecta 

blankets, an interesting but nondestructive phenomenon, was 

noted along the highway system 

in south-central Alaska. These 

blankets, most common on the 

Richardson and Copper River 

Highways, were formed by the 

ejection of generally very fine 

sand, through fissures in the 

ground where the depth to the 

water table was usually less than 

10 feet. The largest ejecta blanket 

was on the Copper River Highway 

about 30 miles from Cordova; it 

covered an area of at least an acre 

to a depth of as much as 3 feet. 

SEISMIC SEA WAVES 

Seismic sea waves that struck 

Kodiak Island destroyed 13 miles 

of the highway net (Plafker and 

Kachadoorian, 1966). The waves 

were particularly damaging to the 

low-lying roadway and bridges at 

Womens Bay, Middle Bay, and 

Kalsin Bay (figs. 7, 25). 

24.-Small landslide on Seward-Anchorage Highway near mile 44.5, along shore of 

Summit Lake. 

The waves ran inland as much 

as 1% miles in Women's Bay, 2% 

miles in Middle Bay, and about 

3 miles in Kalsin Bay. The in- and 

outgoing water was especially violent in Kalsin and Middle Bays 

( P 1 a f k e r and Kachadoorian, 

1966, pl. 3) and in Womens Bay 

(Plafker and Kachadoorian, 1966, 

p. D42). Three miles of road was 

destroyed at Womens Bay, 3 miles 

at Middle Bay, 1 mile at Mayflower Creek, 4 miles at Kalsin 

Bay, and about 3 miles at Twin 

Creeks east of Isthmus Bay. The 

roadways in these areas had to be 

realined because compaction of the 

underlying sediments and regional 

subsidence left them under water 

during high tides. 

Most of the 4-mile stretch of the 

Chiniak Highway from the Kodiak Naval Station to Womens 

Bay was inundated by the seismic 

sea waves, but the roadway was 

only slightly damaged because the 

asphalt pavement prevented extensive erosion. 

The Point Whitshed Road, between Cordova and Point Whitshed, crosses Hartney Bay on an 

artificial fill about 12 feet thick, 

28 feet wide, and about 1 mile 

long. At the time of the earthquake 

the roadway was unpaved. Eighteen feet of the original 28 feet still 

remains; about 10 feet of the inland side of the roadway was cut 

off as if by one stroke of a huge 

cleaver (fig. 26). This remarkably 

straight-line failure could not have 

been along a construction joint because the fill was placed as a unit. 

During the earthquake, severe 

seismic shaking probably generated a longitudinal fracture along 

the axis of the fill about 18 feet 

from the Orca Inlet side or 10 feet 

from the inland side of the fill. 

This fracture was due t~ compaction and lateral displacement of 

the underlying saturated silt and 
C28 

57"40' 

152"35' 

EXPLANATION 

Roadway, dashed 

where destroyed 

• 

Bridges destroyed 

or replaced 

Preearthquake 

shoreline 

Postearthquake 

shoreline 

'~- Approximate limit 

of inundation by 

seismic sea waves 

0 

ALASKA •E:ARTHQUAKE, MARCH 27, 1964 

152"30' 152"25' 

3 MILES 

25.-Pre- and postearthquake shorelines and area of inundation by seismic sea waves on Kodiak Island. 
gravel. When the incoming (from 

left to -right in· fig~ 26") seismic sea 

waves topped the roadway, they 

must have had sufficient force to 

topple the inward 10-foot part of 

the roadway. As the seismic sea 

waves receded, they scoured away 

part of the toppled roadway. 

TECTONIC SUBSIDENCE 

The Alaska earthquake caused 

vertical land changes throughout 

much of south-central Alaska 

(Grantz, Plafker, and l{achadoorian, 1964; Plafker, 1965). 

Where the highways were underlain by areas that were uplifted, 

no long-range damage was done. 

Definite problems did arise, however, where the highway passed 

over low-lying areas that were affected by regional tectonic subsidence. Widespread effects of 

subsidence were not felt until the 

spring tides in April 1964. These 

and subsequent high tides submerged much of the SewardAnchorage I-Iighway around 

Turnagain Arm from mile 75.1 to 

mile 91.0 (fig. 27). The town of 

Portage as well as the high way 

were inundated by the high tide. 

Tectonic subsidence In the 

Turnagain Arm area was about 

5.2 feet with additional local subsidence of ns much as 4.5 feet; 

thus, parts of the Seward-Anchorage llighway subsided 9.7 feet. 

Figure 28 shows the preearthquake shoreline which is mean 

high water and the area inundated 

by the 33-foot tide of April 14, 

1964. 

The low-lying n.reas at the head 

of 'V omens Bay, Middle Bay, 

Kalsin Bay, and the small bay east 

of Isthmus Bay on l{odiak Island 

became subject to flooding during 

high tides. During a 4lj2-foot tide 

· the Chiniak Highway at the head 

of W omens Bay was mostly under 

water. The area had a regional 

t~ctonic subsidence of 5.6 feet plus 

EFFECTS ON THE HIGHWAY SYSTEM 

. 3 to 4 feet of subsidence due to compaction and latera;l displacement of 

sediments'; , thus, total subsidence 

here was 81j2 to 91h feet. 

On Kodiak Island, regional tectonic subsidence plus local differential subsidence required replacing 5 miles of roadway in addition 

to the 13 miles destroyed by 

seismic sea waves. This total of 18 

miles includes about 21h miles of 

roadway at Pasagshak Bay and 

21j2 miles ·at Anton Larsen Bay 

(fig. 7). 

About half a mile of the Glenn 

Highway near mile 27 was inundated during high tides. Tectonic subsisdence was about 2 feet, 

but there must have been another 

6 feet of subsidence due to compaction and lateral displacement 

of underlying sediments-otherwise the roadway would not have 

been flooded during high tides. 

Regional tectonic subsidence 

and local differential subsidence 

have caused a definite long-range 

hazard to the highway system on 

the Seward-Anchorage Highway 

around Turnagain Arm. Because 

space and economic factors do not 

permit a major change of a.linement, the roadway must be 

brought to grade by the addition 

of fill. The fill will have to be riprapped ·because it will be subjected 

to tidal action and erosion during 

high tides. 

DAMAGE TO BRIDGE 

APPROACHES AND 

BRIDGES 

The .Alaska earthquake and attendant seismic sea waves raised 

havoc with the highway bridges in 

south-central Alaska. When the 

seismic shaking stopped, 119 

bridges had been damaged. An a.dditional13 bridges were destroyed 

by seismic sea waves, and 9 more 

had to be replaced because regional 

tectonic subsidence or looal subsidence of the sediments placed them 

under water during high tides. 

C29 

On March 27, 1964, in the 586,-

400 square miles of Alaska, there 

were 480 bridges having an aggregate length of about 77,300 feet. Of 

these, 204 bridges with a total 

length of 36,311 were in southcentral Alaska (tables 13, 14, p. 

058). One hundred forty-one 

bridges or about 30 percent of the 

480 bridges were damaged; 92 

bridges or 19 percent were severely 

damaged or destroyed; and 23,267 

feet or 30 percent of the total 

bridge footage in Alaska required 

replacement. 

If we consider only the bridges 

in south-central Alaska, the statistics become even more staggering. 

Only 63 bridges or 31 percent were 

not damaged; 39 bridges or 19 percent received slight damage; 10 

bridges or 5 percent sustained moderate damage; and 92 bridges or 

45 percent were severely damaged 

or destroyed. Of the total bridge 

footage in south-central Alaska, 64 

percent was damaged severely 

enough to require replacement ( tables 13, 14, p. C58) . The cost of repairing or replacing the structures 

amounted to $25,899,476. This is a 

tremendous loss to any State's 

highway system and economy. 

The bridges on the Copper River 

Highway .that were farthest from 

the epicenter (fig. 1) suffered the 

greatest damage. Of the 53 bridges 

on the highway, 52 were damaged 

and 32 were severely damaged or 

destroyed (tables 13, 14, p. C58) . 

The only bridge tha.t was not 

damaged rested on bedrock and 

spanned the Eyak River a,t mile 

5.9. Table 14 gives the intensity of 

bridge damage on the other highways or roads in south -central 

Alaska. 

Seismic shaking and its effects 

upon the foundations of the 

bridges were responsible for 

damage to 120 bridges. These effects include compaction of the 
26.-Right side of Point Whitshed Road destroyed by seismic sea waves. Waves advanced over roadway from the left and cut 

sharp edge on right side of roadway. View northeast; Hartney Bay is to the right. 

27.-View of Pofltage on Seward-Andhorage Highway during 28-foot tide, after regional subsidence caused by the earthquake. 

Highway is under water, just below railroad grade in far background. Photograph taken August 10, 1964. 
149'15' 61'00' 

Base from U.S. Geologtcal Survey 

Seward D-6, I :63 ,360, I 952 

EFFEC'l\S ON THE HIGHWAY SYSTEM C31 

148'52'30" 

0 3 MILES 

28.-Map of Turnagain Arm showing pre-earthquake shoreline based on mean high water and showing also the area inundated 

by the 33-foot tide of April14, 1964. Tide height datum is mean lower low water. 
032 

sediments upon which the bridges 

rested and lateral displacement of 

the sediments toward free faces. 

Only five bridges on bedrock were 

damaged, and those only slightly. 

The remaining 114 bridges were 

underlain by unconsolidated sediments. 

The damage to roadway fill approaches to a highway bridge can 

easily be explained, but an analysis 

of bridge damage is not so simple. 

There is a definite correlation between the damage to bridges on 

bedrock and to those on sediments, 

but analyses of damage to the 

bridges on sediments is more complex. Damage intensity is not only 

a function of the type of sediment 

but also the type of structure. 

Tables 15-19, p. C59-C66listthe 

bridges on the Copper River, Seward-Anchorage, Glenn, Richardson, and Sterling Highways, respectively, and show the loca;tion, 

length, type, :foundation material, 

and earthquake damage. The descriptions of damage, particularly 

of severe damage or total destruction, are brief and do not include 

all failures. The terms used in the 

tables are shown in figure 29, 

which indicates the various structural elements that make up a typical bridge. 

SEISMIC SHAKING 

The approaches to nearly all the 

bridges in south-central Alaska 

subsided in relation to the bridge 

decks (fig. 30). Even where fill approaches were placed on bedrock, 

some subsidence or compaction 

took place. 

The maximum compaction and 

settlement recorded for any bridge 

approach was 71h to 8 feet at the 

north approach to Tidewater 

Slough 5 bridge on the SewardAnchorage Highway at mile 82.0 

( ta;ble 16, p. C63). There, the roadway is underlain chiefly by sand 

ALASKA .E:ARTHQU AKE, MARCH 2·7, 19·6 4 

;:Approach 

0 0 . 

D 

\1 . 110 . 0 0 

o ~ . ~"'. o : : o"' o . 0 . 0. u . 0 

...., ··o 0 · D 

A 

Bent 

B 

:+-Anchor_....:.: 

:._~ _ _'] bolts ~~-'::] 

Pier 

c 

Q) • I ~. 

.... :I Q) ... o.u 

:I :I 

Cll!:; 1/) 

~ 

Et; 

g Q) 

::.c 

1/) .... 

.c 0 :I 

(/) 

29.-Schematic drawing showing various elements of a bridge. A, view parallel to 

stream ; B, view perpendicular to stream ; 0, view parallel to stream. 

and silt. On the Seward-Anchorage Highway all the bridge approaches subsided because of compaction except the structures spanning Quartz Creek, Summit Creek, 

Colorado Creek, Spokane Creek, 

Bertha Creek, and Lyon and Tincan Creek Quartz Summit and 

Colorado Creek bridges are short 

22-foot spans anchored in bedrock 

with a thin veneer of coarse gravel 

for a.pproaches. Lyon and Tincan, 

Bertha, and Spokane Creek 

bridges are on a thin ·layer of 

coarse gravel overlying bedrock 

and do not have thick approach 

fills. 

The factors chiefly responsible 

fot large subsidence of approaches 

on the Turnagn,in Arm section of 

the Seward-Anchorage Highway 

were ( l) the highway is underlain 

by fine-grained silt and sand and 

silty gravel, (2) the water table is . 

{ 
close 'to the surface, generally 

within 2 feet, and ( 3) most of the 

roadway and approach fills are 

thick. In places between Twentymile River and the town o.f Portage there was as much as 12 feet 

of fill. All these factors combined 

to cause failure of the underlying 

confining sediments by lateral displacement toward the creek and 

displacement i1ormal · to the roadway fill and approach. 

All the bridge approaches on 

the Copper River Highway underwent compaction and subsidence 

by seismic shaking with the exception of those at the Eyak River 

bridge at mile 5.9. Maximum compaction of 3 feet occurred at the 

east approach of Copper River 2 

bridge at mile 27.1. Figure 31 

shows the vertical displacement of 

the approach. This approach fill 

EFFECTS ON THE HIGHWAY SYSTEM C33 

30.-Subsidence of bridge approach fill at Tidewater Slough 2 bridge, mile 76.4, 

Seward-Anchorage Highway. View is west. Photograph by Helen Foster. 

31.- View looking west, Copper River bridge 2, mile 27.1, Copper River Highway. Approach subsided 3 feet as a result of seismic 

shaking. 
a4 ALASKA EARTHQUAKE, MARCH 2 7, 1964 

32.-Mound formed by bulldozing of approach fill against bridge deck (foreground), 

at north end of Copper River 12 bridge, mile 36.9, Copper River Highway. 

is about 10 feet thick and is underlain chiefly by silt and sand. 

Displacement of the north approach of Copper River 12 bridge, 

mile 36.9 on the Copper River 

Highway (fig. 32), was unique. 

Here, instead of subsiding, the approach fill formed a mound 18 

inches high against the north 

abutment of the bridge. The silty 

gravel fill was moved laterally 

against the resisting abutment and, 

because the bulkhead did not fail, 

the mound was formed. A similar 

mound was formed at the Little 

Tonsina River bridge on the 

Richardson Highway by a landslide. 

Although the seismic shaking 

caused some compaction and subsidence on all the Copper River 

Highway bridge approaches, there 

were no large ~rertical displacements chiefly because (1) the finegrained sediments that underlie 

much of the lligh\vay are coarser 

than those that underlie the Turnagain Arm section of the SewardAnchorage Highway where 

approach subsidence was so extensive, (2) the water table on the 

Copper River Highway is deeper 

than that a Turnagain Arm, and 

(3) the roadway fills are generally 

only a thin veneer on the original 

ground. 

The bridge approaches on the 

Glenn and Sterling Highways sustained only minor damage. However, even in fill approaches placed 

on bedrock some subsidence or 

compaction took place. The Chickaloon River bridge (mile 78.2) and 

the Puritan Creek bridge (mile 

89.3) on the Glenn Highway rest 

on bedrock, but the approaches are 

constructecl of sandy gravel fill. At 

Puritan Creek the east approach 

has 10 feet of fill that subsided 3 

inches ; the west approach has a 

6-foot fill over bedrock and subsided 1 inch. The Chickaloon River 

bridge approaches have 4 to 5 feet 

of sandy gravel fill; both approaches compacted or subsided at 

least 1 inch. Maximum subsidence 

of approaches was 3 inches recorded at Puritan Creek and at the 

west approach of the Little Nelchina River, mile 137.5. 

On the Sterling Highway both 

the approaches to the Kenai River 

bridge, mile 48.9, subsided 8 inches 

(table 19, p. C66). Subsidence was 

not expressed ax, single displacements between the abutments and 

the approaches, but instead of 

spread over an area of several feet. 

Maximum vertical displacement 

of bridge approaches on the Richardson Highway was about 6 

inches (table 18, p. C65). The displacement af nearly all localities 

~vas in glacial sediments, although 

the Stuart Creek bridge, mile 45.6, 

the approaches are thick fills overlying bedrock. The main reason 

for the lack of large vertical displacements of a,pproaches and 

roadway is the fact that the depth 

to the water table genlarally is more 

than 6 feet and commonly more 

than 10 feet. 

Many types of bridges were in 

use in south-central Alaska at the 

time of the earthquake (see tables 

15-19, p. C59-C66). If th~ 

bridges had rested on the same 

kind of sediments, the damage 

could have been analyzed with relative ease, but because the structures rested on different kinds of 

sediments, analysis was more difficult. The structural damage at first 

appeared to be random, but 

further studies indicated a pa,ttern 

of failure. 

The bridges failed in various 

ways as a result of seismic shaking. Some bridges collapsed completely; in others, anchor bolts 

sheared off, pilings were displaced, 

abutments were crowded, structures were compressed, and structural elements were displaced horizontally or vertically. Failure of 

the bridges on the Turnagain Arm 

stretch of the Seward-Anchorage 

Highway, was partioularly spectacular. These bridges, simple Tbeam spans on timber bent substructures, were underlain chiefly 

by silt, sand, and silty gravel, so 

most of the wooden piles were bottomed in this material. 
EFFECTS ON THE HIGHWAY SYSTEM c35 

33.-Wreckage of Portage Creek bridges 2 ad 3, Seward-Anchorage Highway. The Alaska Railroad grade and bridges are in 

foreground of highway. Photograph by U.S. Army. 

Damage to these bridges occurred because of (1) failure of the 

wood bents, (2) lateral displacement of the sediments toward the 

creek which forced Che abutments 

closer together and literally 

crowded the deck and compressed 

the bridge (fig. 33), and (3) failure at the tie between the substructure and superstructure. The 

seismic shaking and lateral displacement of the sediments pulled 

the wood ties off the caps, and the 

superstructure became independent of the substructure. The deck 

or superstructure had a vertical as 

well as a horizontal component of 

movement during the earthquake. 

Eventually the wood bents failed 

beneath 'the superstructure and the 

bridge collapsed. In many bridges 

the wood piles were driven 

through the reinforced concrete 

deck (fig. 34). Eyewitness reports 

show that the decks Bad an upand-down motion period of about 

1 second. That is, a wave apparently passed through the deck, 

and, as it passed through, the 

superstructure moved up and 

down in aboult a 1-second cycle. It 

is hard to believe that a wood pile 

could be driven through a reinforced concrete deck by this motion, and that at many places the 

saw marks could then still be seen 

at the end of the piles. Apparently 

at the same time the deck was coming down, a ground wave was displacing 'the piles upward. These 

statements should not be construed to mean that the piles actually had a higher altitude after 

the earthquake than they had before: Nowhere along the highways in south-central Alaska had 

piles been pulled out of the ground 

or displaced vertically upwards. 

On the contrary, all the piles were 

at lower altitudes after the earthquake, partly because of the 

pounding of the deck upon the 

piles but primarily because of tlhe 

lack of strength of the sediments 

suppo~ting the piles. Seismic shaking partially or completely liquefied the sediments around the piles. 

The overhead at the east end of 

Snow River Crossing was destroyed by seismic shaking. It 

rested on wood piles and collapsed 

upon the tracks of The Alaska 

Railroad (fig. 35). 

Among the severely damaged 

bridges along the Copper River 

Highway was the Million Dollar 

Bridge at mile 49.0. This bridge, 

constructed in 1910 by the Copper 

River and Northwestern Railway, 

made it possible to carry copper 

ore from Chitina to Cordova. The 

railroad was abandoned before 

World War 11, and most of its 

larger bridges and roadbed from 

Cordova to mile 51 were reoccupied by the Copper River Highway. The rails were salvaged and 

used as piles on 22 of the highway 

bridges. Three rails (about 50- 

ponnd rails that is, rails that 

weigh 50 pounds a linear yard) 

were welded heads together and 

driven, but there was a history of 

failure even while they were being 

driven. 
C36 ALASKA .EARTHQUAKE, MARCH 2 7, 19 64 

34.-(=ollapsed bridge across Twentymile River. Railroad bridge in upper right photograph did not collapse. 

The Million Dollar Bridge, 

which spans the Copper River as 

it leaves Miles Lake at the mouth 

of Copper River canyon, is a historic structure in Alaska. The 

completion of this bridge is indeed 

a tribute to the engineers and construction men 1~110 built it. Rex 

Beach, in his book "The Iron 

Trail," published in 1913, did 

much to bring these men to the 

attention of the world. 

The bridge consists of four steel 

truss spans 400, 300, 450, and 400 

feet long. Migliaccio (1966) stated 

that caissoiis for piers 1, 2, and 3 

were landed at 36, 36, ancl 50 feet 

below- the stream bed. The founclatioils for all the piers except pier 

3 are sand and gravel and boulders from 1 to 10 cubic feet in 

35.-Overhead at easlt side of Snow River Crossing. Structure collapsed uwn tracks Miglia('cio that 

of The Alaska Railroad. Photograph by U.S. Army. the foundation supporting pier 3 

is sand, gravel, and boulders 

smaller than those underlying the 
EFFECTS ON THE HIGHWAY SYSTEM c37 

36.-Million Dollar Bridge, Copper River Highway; No. 4 span off No. 4 pier. View is southwest. 

other piers. Jlaximu~n foundation Alaska Department of Highways : expansion slots. Span 1 moved south 

pressures were less than 4 tons per 

square foot. 

Allthough the bridge was very 

severely damaged (figs. 36, 37), 

the Alaska Department of Highways will no doubt malie all eEorts 

to save it because of its historic 

value. In view of the magnitude 

of this venture a inore complete 

clescription of damage is presented 

here than is possible in table 15. 

The following damage report was 

made by Harry Golub of the 

- 

Abutment 1 relatively undamagecno sign of movement of abutment itself. 

Span 1 is displaced 1% inch south and 

1 foot upstream. The top of the backwall and wings are cracked and chipped 

from pounding of deck. Backwall is 

pockmarked from rivets at end of truss. 

New stringer seats have small sections 

of concrete broken away by contact with 

end of truss. Anchor bolts are sheared. 

Truss apparently undamaged. At pier 

2 both spans have moved enough to 

turn their rollers over flat and bend 

their anchor bolts. In their final position bolts are about in the middle of 

and span 2 moved north. The spans 

are jammed tight on upstream side, separated by about 2 inches downstream, 

jamming together pulverized sliding 

beams between spans as well as the ends 

of the concrete deck and bent the finger 

joint and its connections. The bottom 

chords of the trusses show some crimping from passage over the rollers, but 

actual damage is difficult to assess without raising trusses. Only a short length 

of chord and some of its connecting angles are affected. 

At pier 3 the following displacements 

were measured. 
C38 ALASKA EARTHQUAKE, MARCH 2 7, I964 

37.-Collapsed No. 4 span and horizontal fracture in No. 4 pier of Million Dollar Bridge, Copper River Highway. View is 

northeast. 

Upstream bearings : 

Span 2 

19 inches upstreani 

10 inches nol.th 

Span 3 

18 inches upstream 

3 inches noFth 

There is about 3% inches between 

ends of trusses. 

Downstream bearings : 

Span 2 

19 inches upstream 

13 inches north 

wan 3 

19 inches upstreani 

4 inches north 

Ends of trusses jammed togetherall anchor bolts sheared. Sliding beams 

between spans have been pulverizedthose on railroad stringer lines have 

damaged the end floor beam webs. Joint 

angles and ends of concrete slab badly 

damaged. Piers 2 and 3 seem to have 

suffered no structural damage. Pier 4 

is virtually destroyed. The upper portion has split into three parts, with 

each of the end pieces separated from 

the middle by a crack up to 2 feet wide. 

The middle portion has a vertical crack 

running completely through it. The 

upper half of the pier has also sheared 

horizontally and has moved about 2 feet 

south in respect to the lower half. The 

entire pier has a list toward the south. 

There is no evidence of reinforcement 

in the upper pier and failures seem to 

be along construction joints. The bearings of span 3 are displaced 9 feet 9 

inches from their former position on 

pier 4 in a northward direction and approximately 6 feet transversely. Bottom 

lateral bracing is mutilated from contact with the pier and the bottom chords 

hare been dragged over the concrete, 

popping rivets and doing an indeterminable amount of damage to the bottom 

chord and its connections. 

Span 4 has dropped off pier 4 and 

is in the river, probably resting on the 

bottom since the river is quite shallow 

north of pier 4. The truss and concrete 

deck appear undamaged from Lo' to 

L,, where the deck is broken and the 

chords apparently bent or brolien by the 

fall. Verticals L, U, are bent completely 

out of shape in compression. End posts 

show no damage above water. The span 

is collecting some drift, but the shallowness of the river protects it from fast 

water or large pieces of floating ice. 

The span may stay where it is for 

some time. 

Abutment 5 does not show signs of 

any major damage. There is, of course, 

some spalling and breaking of concrete 

at the bridge seats caused by the fall of 

span 4 and all anchor bolts are either 

broken or bent, but the abutment itself 

seems structurally sound. 

Mr. Golub's description of damage to the Millioil Dollar Bridge 

indicates that some crowding of 

the superstructure relative to the 

abutments and compression of the 
spans against one another has OCcurred. The abutments moved an 

unknown amount toward the center of the Copper River because of 

lateral displacement of ~ediments 

to an unknown depth. At pier 3 

the relative displacement of the 

pier was upstream. Either the 

superstructure moved downstream 

or, more probably, the pier moved 

upstream because of lateral displacement of the underlying sediments. The largest free face is upstream, toward Miles Lake. There 

was probably some slumping or 

spreading of sediments upstream 

into the deep lake, which would account for the apparent movement 

of the piers upstream rather than 

downstream. 

During the earthquake all the 

bridges supported by piles made of 

the old rails were severely damaged or destroyed (table 15, p. 

C59) because the brittle rail piles 

were unable to withstand the 

severe seismic shaking generated 

by the earthquake (fig. 38). Figure 

39 is a photograph of a collnpsed 

bent on Copper River 5 bridge, 

mile 35.0, and figure 40 is a view 

showing how the bent was constructed. The concrete between the 

rails provides protection to the 

bent against winter ice. This bent 

either broke because of partial or 

total liquefaction of the supporting fine-grained sand and silt sediments. The bridge deck collapsed 

because of differential movement 

of the deck and bent, lateral displacement of the bent, or a combination of the two. 

The Copper River 2 bridge consisted of a reoccupied steel truss 

bridge of the Copper River and 

Northwestern Railway and n concrete deck supported by welded 

rail bents. The truss moved eastward relative to the concrete section of the bridge (fig. 41). The 

EFFECTS ON THE HIGHWAY SYSTEM c39 

38.-Broken rail piles on Scott Glacier 6 bridge, mile 5.9, Copper River Highway. 

39.-Collapsed bent and deck of Copper River 5 bridge, mile 35.0, Copper River 

Highway. 

bridge elements were compressed 

or crowded agzzinst each other by 

the movement caused by the seismic shaking. 

Lateral disp1:~cement of sediments toward a free face caused 

movement of the abutments toward the middle of the stream and 

made the superstructure too long 

for the abutments; the structure 

mas thus compressed or crowded. 

Most if not all of this horizontal 

displacement was taken up at only 

one end of the structure (compare 

figs. 42, 43). Figure 42 shows the 

west abutment of Scott Glacier 5 
C40 ALASKA EARTHQUAKE, MARCH 2 7, 1964 

40.-Collapsed deck on Copper River 5 bridge, mile 35.0, Copper River Highway. 

Conmete between rail piles is to protect rails against ice. 

41.-Contact between steel truss and concrete deck on pier 26, Copper River 2 bridge, mile 27.1, Copper River Highway. 
EFFECTS ON THE HIGHWAY SYSTEM C41 

42.-West abutment of Scott Glacier 5 bridge, mile 9.2, Copper River Highway. 

Concrete cap displaced 2 inches to the left off the pile bent. Compare with figure 43. 

bridge, mile 9.2, on the Copper 

River Highway ; here the concrete 

cap was displaced westward off the 

pile bent. Figure 43 shows the east 

abutment of the bridge ; at this end 

of the structure, the superstructure 

rammed through the wood abutment and was displaced about 2 

feet to the east relative to the abutment. Maximum horizontal displacement of superstructure relative to substructure or compression 

of a brldge on the Copper River 

Highway was 6 feet. This displacement occurred at the north abutment of the Clear Creek bridge at 

mile 41.0 (fig. 44) and also at the 

south abutment of the Copper 

River 16 bridge at mile 38.1. 

The sediments that underlie the 

Copper River Highway become 

progressively coarser eastward toward mile 22.3; they become progressively thinner from about mile 

16.6 to mile 22.3, where bedrock is 

exposed. Thirteen slightly damaged bridges are in this stretch of 

structures. Rather they should be 

compared with similar bridges at 

miles 14.8,15.3,15.8,15.9,16.1, and 

16.5. The bridges at miles 14.8 and 

15.8 were moderately damaged ; 

those at miles 15.3, 15.9, 16.1, and 

16.5 were severely damaged or destroyed. This pattern of damage to 

similar bridges affords an opportunity to evaluate the effects of 

geologic environment on the 

amount of damage. Those bridges 

which received moderate to severe 

damage or were destroyed were 

underlain by a thicker prism of 

sediments than those that were 

only slightly damaged. The thinner the underlying sediment the 

less the damage, and the colarser 

the grain size of the underlying 

sediments the less the damage 

from seismic shaking. 

Seismic damage to the bridges 

on the Sterling Highway was light 

compared to that to bridges on the 

Seward-Anchorage and Copper 

River ~i~hwa~s-(com~are figs. 2, 

3, 6; tables 15, 16, 19, p. C59, C62, 

C66). The Quartz Creek bridge at 

mile 41.7 is underlain by a, finegrained thin veneer of silt and 

sand overlying stream gravel. The 

damage to this bridge was more 

than might have been expected beoause the structure was resting on 

ooncrete abutments and concrete 

piers. Damage was chiefly due to 

lateral displacement of the abutthe highway, but, they are all 

43.-East abutment of Scott Glacier Creek 5 bridge 'at mile 9.5 Capper River 'Tooden structures and Highway Super&ru&ure is displaced about 2 feet to the right, relative to the 

be compared with other types of abutment. Compare with figure 42. 
(742 ALASKA EARTHQUAKE, MARCH 27, 1964 

44.-North abutment of Clear Creek bridge 329, mile 41.0, Copper River Highway. Superstructure is displaced to the right 

relative to the abutment. 

ments toward the center of the 

creek, which placed the structure 

in compression. The bridge at mile 

48.9 crossed the ICenai River at the 

outlet of Kenai Lake. The bridge, 

which rested on silt, sand, and 

gravel deposited by the river, collapsed during the earthquake. The 

wood piles, on some of which the 

saw marks were still visible \\--hen 

the bridge was inspected by survey 

personnel, were driven through 

the reinforced concrete deck (p. 

C43 ; fig. 45). 

The three concrete bridges that 

span Portage Creek Overflows 

1, 2, and 3, at miles 3.3, 3.8, and 

4.3, respectively, on Portage 

Glacier Road were severely damaged. These bridges which rest on 

silt, sand, and gravel, were severely compressed after the earthqnake ant1 had to be replaced. 

SEISMIC SEA WAVES 

The train of 10 seismic sea 

waves associated with the Alaska 

earthquake destroyed 13 bridges 

in south-central Alaska, 12 on 

Kodiak Island, and 1 on the Point 

Whitshed Road at Hartney Bay. 

Of the 12 bridges destroyecl on 

Kodiak Island, 11 were on the 

Chiniak Highway and 1 at Mission Ray in the town of Kodiak. 

The 11 bridges on the Chiniak 

Highway that were destroyed by 

waves spanned Sargent Creek at 

mile 5.0, Russian Creek at mile 

5.2, the American River at mile 

13.3, Mayflower Creek at mile 17.2, 

the Kalsin River at mile 22.8, West 

I 

and East Forks of the Twin River 

ac miles 32.7 and 32.9, respectively, 

and four small unnamed creeks at 

i 

miles 12.0,12.3,13.6, and 33.7. 

Eyewikness reports indicate 

that the first seismic sea wave was 

like a rapid rise of sea level and I 

that the following waves were actually breaking. The damage to 

the bridges mas due to the rapid 

retreat of the initial wave and to 

subsequent breaking waves. The 

first outgoing seismic sea wave 

was in part responsible for de- 
EFFECT8 ON THE HIGHWAY SYSTEM -3 

struction of some of the bridges, 

but the subsequent incoming waves 

played the major role. 

The waves destroyed the structures either by moving the superstructure off the substructure or 

by destroying the bents supporting 

the deck of the bridge. Most of the 

decks that were moved off their 

piles were carried upstream. Some 

ruins, however, were not found 

and no doubt had been carried out 

to sea by the outgoing waves. 

REGIONAL SUBSIDENCE AND 

LOCAL SUBSIDENCE 

Several otherwise undamaged 

bridges had to be replaced on the 

Chiniak Highway and between 

mile 75.1 and mile 105 on the 

Seward-Anchorage Highway because of flooding caused by re- - 

gional tectonic subsidence and 

local differential subsidence. This 

postearthquake flooding by high 

tides affected the sites of 44 

bridges in south-central Alaska 

and in itself would have required 

replacement of the bridges; 35 of 

the 44, however, had already been 

damaged by either seismic shaking or seismic sea wave. The nine 

undamaged bridges that had to be 

45.-Collapsed bridge acrw Kenai River at Kenai Lake, mile 48.9, Sterling Highway. Wood piles are driven through the collapsed reinforced concrete deck. 

Photograph by Helen Foster. 

replaced because of flooding are Bay, and (3) the bridges on the 

on Kodiak Island and include (1) Chiniak Highway spanning Lost 

three bridges at Pasagshak Bay, Creek at mile 5.8, Salonie Creek 

(2) the Red Cloud River bridge at mile 6.4, Frank Creek at mile 

(mile 7.7) and an unnamed creek 23.6, and an unnamed small creek 

bridge at mile 9.0 at Anton Larsen at mile 24.9. 

GEOLOGIC FACTORS INFLUENCING DAMAGE INTENSITY 

GRAIN SIZE OF 

SEDIMENTS 

The type of sediments upon 

which the highway rested played 

a major role in the amount and 

type of damage the structures experienced. For example, highway 

roadways underlain by coarsegrained sand and gravel were 

fractured substantially less than 

were roadways underlain by finer 

grained sand and silt. Roadways, 

fills, and approaches constructed 

of coarser grained sediments also 

were not fractured as much as 

those constructed of finer material. 

For example, in the Portage area, 

the Seward-Anchorage Highway 

and The Alaska Railroad are 

adjacent to one another. The highway roadway is constructed of 

well-graded (poorly sorted) compacted silt, sand, and gravel 

whereas the railroad roadbed is 

constructed primarily of poorly 

compacted sand and gravel. The 

finer grained highway fill was substantially more fractured than the 

railroad fill. 

Structures on fine-grained sediments subsided more than those on 

coarse-grained sediments. For example, maximum subsidence of a 

highway roadway of as much as 

11 feet occurred at Snow River 
C44 

Crossing on the Seward-Anchorage Highway. The roadway subsided 71h to 8 feet at mile 82.0, 

Seward-Anchorage Highway, on 

the north approach of Tidewater 

Slough 5 bridge. Both of these 

areas are underlain by sand and 

silt. The subsidence was due to the 

lateral displacement and compaction of the underlying sediments. 

THICKNESS OF 

SEDIMENTS 

The thickness of sediments also 

influenced the extent of damage. 

The pnsm of sediments that 

underlie the Copper River Highw~y from mile 5.9 to mile 22.3 

thins from mile 16.6 to mile 22.3 

where bedrock is exposed. The 

sediments also became progressively coarser eastward, toward 

mile 22.3. In this section of the 

highway there were 13 slightly 

damaged all-wood bridges whereas 

all-wood bridges west of mile 16.6 

received severe damage or were 

destroyed. The two geologic ·fa·ctors that controlled the extent of 

damage to the all-wood bridges 

were: the thinning of the prism 

of sediments underlying the roadway, and the progressive coarsening of the sediments eastward. 

DE.PTH OF WATER TABLE 

Other than foundation material, 

the most important geologic factor 

controlling damage is the depth 

of the water table. In any given 

geologic condition, the closer the 

water table to the surface, the 

more damage to the highway 

system. For example, at Snow 

River Crossing where the maximum compaetion of 11 feet occurred, the water table is within 

1 foot of the surface .. At Tidewater 

Slough 5 bridge, the water table 

is within 4 feet .of the surface. In 

the Turnagain Arm area on the 

ALASKA ·EARTHQUAKE, MARCH 27, 1·964 

Seward-Anchorage Highway, the 

roadway from miles 75.1 to 81.0 is 

under lain by silt, sand, and fine 

gravel. The most eX'tensive fracture damage along the highway 

occurred between miles 78.4 and 

81.0 where the water table is generally within 2 to 3 feet of the 

surface. Between miles 75.1 and 

78.4, where the damage was less 

severe, the water table is generally 

1 foot deeper. 

AMOUNT OF COMPACTION 

During the earthquake both the 

sediments underlying the roadway 

and the roadway fill itself compacted. The exact amount of compaction of each IS difficult to 

determine; however, most of the 

subsidence was in the underlying 

sediments. The sediments were not 

only compacted but were htterally 

displaced from beneath the roadway fill. 

The roadway subsided as much 

as 11 feet, but the surrounding 

ground did not subside as much. 

Data obtained from water wells indicates that maximum measured 

compaction of the undisturbed 

sediments did not occur at Snow 

River Crossing or in the Portage 

area, but a Homer Spit near the 

town of Homer. 

Homer Spit is underlain by the 

following unconsolidated deposits 

(Grantz, Plafker, and Kachadoorian, 1964) : 

Silt, sand, Feet 

and gravel _ _ _ _ _ 0-200 

Sand ____________ 200-289 

Marine sand and 

clay ___________ 289-321 

Soft clay, locally 

mushy ________ 321-462 

Hard clay _______ 462-468 

Kenai(~) 

formation _ _ _ _ _ 468-4 77 + 

Here the sediments compacted at 

least 2.5 feet. Compaction no doubt 

occurred in the upper part of the 

silt, sand, and gravel layer. 

The log of the water well at the 

Union Oil Station at Portage 

shows that the station is underlain 

(Grantz, PI afker, Kachadoorian, 

1964) by: 

Feet 

Sand and graveL___ 0-20 

Clay ______________ 20-425 

Sand -------------- 425-426 

Clay -------------- 426-600 

The floor of the station subsided 

16 inches around the casing of the 

well. Comparison of the data from 

Homer Spit and the Union Oil 

well at Portage may seem invalid, 

in as much as the well at Homer 

Spit had no structure around it, 

whereas the one at Portage did. 

However, the author feels that 

comparison is valid, because maximum compaction in a given area 

occurred where a structure was 

placed on original ground. Therefore, the 16 inches at the Union 

Oil Station is a maximum figure 

for compaction of original ground 

at Portage. 

The chief factors responsible for 

the amount of compaction are the 

coarseness and the thickness of the 

sediments subjected to seismic 

shaking. The coarser the sediments 

the more -they are compacted, and 

the thicker the sediments the more 

they are compacted. For example, 

there is 200 feet of silt, sand, and 

gravel at Homer Spit and 20 feet 

of sand and gravel at the Union 

Oil Station at Portage. According 

to the well logs the Homer Spit 

sediments are finer, but the author 

examined both sites and found that 

the Homer Spit sediments are actually coarser. The apparent discrepancy is due to the fact that the 

wells were logged by two different laymen. 

The depth to which compaction 

by seismic shaking extends in the 

undisturbed ground is unknown. 

-~ 
. . 

Boring 5 (2-5-62) 

• Elev 439.5 ft 

Highway 

station 

37+00 

0 

EFFEC'DS ON THE HIGHWAY SYSTEM 

Boring 2 (6-22-64) 

Elev •439 ft I 

I 

53 ft 

20.4 FEET 1 '-------' Elev 439ft Boring 1 (6-19-64) 

1-

LIJ 

LIJ 

u.. 

~ 

z 

0 

i= 

c( 

> LIJ 

..J 

LIJ 

440 

430 

420 

410 

400 

390 

380 

370 

360 

350 

10-in California sampler 

driven with 140-lb 

hammer dropped 30 

in 

A 

Boring 6 (1-17-62) 

Ele~ 439.5 ' ft tv 

H1ghway 

-::~~; 

440 

430 

420 

410 

1-

LIJ 

400 LIJ 

u.. 

~ 

390 z 

0 

i= 

c( 

> 380 LIJ 

..J 

LIJ 

370 

360 

350 

.C45 

25 50 100 Blows per foot 

340 25 50 100 Blows per foot ·340 

B 

46.-Sketch of boring locations (A.) and pre- and postearthquake penetrometer tests (B) at Snow River bridge 605, mile 17.7, 

Seward-Anchorage Highway. Data ·after George E. Utermole. Jr., Alaslm Department of Highways . 

The only data, available about 

depth of compaction are from the 

highway and railroad roadbeds, 

but these are engineered or semiengineered fills placed upon the 

sediments. Furthermore, during 

seismic shaking, some of the vertical displacement of the highway 

roadway or railroad roadbed is 

due to lateral displacement of the 

underlying sediments. The railroad's Twentymile bridge rests 

upon piles about 60 feet deep. The 

right-of-way to the bridge approaches subsided 1 to 1112 feet 

more than the bridge (Grantz, 

Plafker, J{achadoor.ian, 1964). 

Thus, the top 50 to 60 feet of the 

unconsolidated material must have 

compacted relatively more than 

the material below the piers. 

The Alaska Department of 

Highways conducted some postearthquake penetrometer tests at 

Snow River Crossing Bridge 605, 

mile 17.7, on the Seward-Anchorage Highway and compared the 

results with preearthquake data. 

George E. Utermole, Jr., foundation geoiogist, Alaska Department of Highways, suggests that 

the postea.rthquake density of the 

sediments underlying Snow River 

Crossing Bridge 605 is greater 

than the preearthquake; however, 

he points out that ahow much of 

this increase in density is due to 

the earthquake· cannot be established" (Alaska Dept. Highways, 

unpub. d~tta). Figure 46 shows the 

location of the borings and the results of the tests. 

LIQUEFACTION OF 

SEDIMENTS 

Failure bec;ause of lique£actio11 

of saturated soils was extensive in 

south-central Alaska, especially 

at the Snow River Crossing 

and Turnagain Arm sections of 

the Seward-Anchorage Highway. 

Failure developed locally at partial liquefaction before comple.te 

liquefaction of the saturated soils. 

However, at Snow River Crossing, 

Turnagain Arm, and on the Rich-
C46 

ardson Highway from mile 0.0 to 

5.0, most of the soil was completely 

liquefied. 

Liquefaction. was responsible 

for both vertical and horizontal 

displacement of sediments. The 

sediments underlying the roadway 

where liquefaction occurred actually flowed out and downslope 

from underneath the roadway fill. 

Where this flow occurred, the 

roadway (1) subsided into the 

sediments and at some places, as 

at the Snow River Crossing, was 

completely submerged into the 

sediments, ( 2) was displaced laterally, and (3) was fractured. 

Statement by eyewitnesses that 

water spouts continued for seve:r;al 

minutes after the seismic vibration 

stopped at Portage indicate that 

failure of the sediments underlying the roadway in the area must 

also have continued after the 

earthquake had stopped. 

Field tests by the author and 

M.G. Bonilla at Portage also indicated that liquefaction continued 

after the vibrating force was removed. A small plot underlain by 

silt was selected for the test. Prior 

to any vibration the silt looked 

dry and one could walk upon it 

without difficulty. The silt was vibrated by foot for about one-half 

minute at which time moisture began to collect at the surface. When 

moisture appeared, the vibration 

· was stopped. The depth of liquefied silt was 11;2 inches. The water 

continued to seep out, and in 2 

minutes it started to flow out as 

fountains in the center of the vibrated mass. Four minutes after 

the force was applied, water began 

to flow out of the liquefied jellylike mass of silt. After 7 minutes 

the water began to clear up, although it was still flowing. The 

depth to firm ground had migrated down to 4 inches within 8 

minutes after vibration was 

ALASKA EARTHQUAKE, MARCH 27, l964. 

stopped. The test was abandoned 

after 8 minutes. The area that was 

liquefied was about 18 inches 

square and the softest spot was in 

the center where the initial :force 

was applied. 

The sediments that underlie the 

Snow River Crossing :were especially prone to liquefaction. During testing in 1962, many of the 

samples collapsed In sampling 

tubes when vibrated or when a 

shock was applied. In addition, 

some of the silt contained gases 

(derived :from the decomposition 

of organic debris in the silt) under 

pressure ·and was thixotropic. 

Mrs. Hadley Roberts of Lawing, Alaska, described what occurred at Snow River to a :friend. 

Part of the letter is quoted here: 

• • • Don and Ed Estes had been 

caught in the mile stretch crossing 

Snow River and the fiats. They said the 

whole highway across there was waving 

up and down like someone was shaking 

a blanket. As it would heave up the 

pavement would crack and it would 

come together again as it settled down. 

Finally the mud started oozing through 

tiie cracks and they no longer would 

come together, and the pavement then 

started settling into the mud. They 

finally had to abandon the car about 

50 yards from the other side as the 

cracks were too big. They ran for bedrock with the mud licking at their 

heels. This was quite a run for them 

as it was all uphill now and lots of 

cracks to jump over. Their car was 

pulled out of the mud a few days 

later. • • • 

This description brings out three 

impo~tant facts: ( 1) fractures developed before liquefaction of the 

sediments and were caused by seismic ground waves, (2) liquefaction 

did not occur immediately, and (3) 

the roadway, although cracked, 

settled into the underlying sediments after liquefaction developed. The first point appears to 

conflict with the statement made 

earlier on .this page that when 

liquefaction occurred the underlying sediments flowed out and 

downslope :from beneath the roadway, and that this outflow caused 

:fracturing of the roadway. The 

:fractures at Snow River Crossing 

were first caused by shear and tension :failure, because the roadway 

was differentially displaced laterally; additional later :fractures 

may have been caused by liquefaction. 

LATERAL DISPLACEMENT 

Seismic shock was the chief 

cause :for lateral displacement of 

sediments. As seismic ground 

waves passed through the ground, 

they imparted a motion to the sediments similar to that which a vibrating table does to debris upon 

it. The sediments were displaced 

laterally downslope or toward a 

:free :face. This type of :failure was 

extensive In the Copper River 

Highway and was responsible :for 

moving bridge abutments toward 

the centers of creeks. When this 

movement occurred, a bridge was 

·either compressed or, more commonly, the superstructure became 

substantially too long :for the span 

between the abutments and one end 

of the deck was displaced as much 

as 6 :feet over an abutment. Lateral 

displacement due to seismic shock 

not only moved the abutments, 

piers, and bents toward the center 

of the creek, but it also moved 

them upstream or downstream. 

As the sediments were displaced 

laterally, the roadway :failed in 

tension and fractures formed. 

Some of these fractures formed 

during the passing of the seismic 

ground wave 'before the actual displacement of 'the sediments. 

Lateral displacement and subsidence occurred in bridge approach 

fills overlying bedrock owing to 

seismic shaking; it was noted even 

in completely dry fills less than 10 

feet thick. 

< 
EFFECTtS ON THE HIGHWAY SYSTEM C47 

ENGINEERING FACTORS INFLUENCING DAMAGE INTENSITY 

Although geologic factors played 

the major role in controlling intensity of damage to the roadways and bridges, they were by no 

means solely responsible. The engineering characteristics of the 

roadways and bridges also influenced the damage intensity. 

In low-lying saturated areas, especially those at Portage and at 

Snow River, the roadway fill had a 

higher density than the supporting underlying sediments. In 

short, the fill was floating upon the 

sedimen1ts. The thicker the fill, the 

Superstructure Substructure Foundation 

Concrete Concrete 

abutments Bedrock 

Concrete Concrete Sediments abutments 

Steel Concrete Sediments abutments 

Concrete Concrete Sediments piers 

Concrete Wood Sediments 

Wood Wood Bedrock 

Wood Wood Sediments 

Steel Concrete 

piers 

Sediments 

Steel Wood Sediments piles 

Steel Railroad Sediments 

rails 

Steel Wood Bedrock 

Steel Steel Bedrock 

Steel Concrete Bedrock piers 

heavier the load on the underlying 

sediments. When the e-arthquake 

struck, the sediments were unable 

to support the roadway and failed. 

At Snow River, the roadway locally sank out of sight into the sediments. Failure, no doubt, first occurred at sites where fills were 

thickest. The maximum thickness 

of fill in the Turnagain Arm section of the Seward-Anchorage 

Highway was at about mile 80.5 

near the Twentymile River and 

was about 12 feet. The geologic 

conditions from mile 78.4 to mile 

D A M A G 

None Slight Moderate 

381-1137~1 1138-1139 

~ 

~ ~ ~ 9 

~ 

~ I § 0

~ 

~ 368-369-370-371-372-373- I 37 4-375-376-377-378-379-395 § 4 

~ ~ 

~ 3 

~ 

~ 

00 ~ 

~ ~ 0 

81.0 are similar, yet the roadway at 

mile 80.5 was the most severely 

damaged by the earthquake. 

Therefore, it is proposed that under given g~ologic conditions, especially in saturated soils, the 

thicker and heavier the fill, the 

greater the damage to the roadway. 

An analysis of the damage to 

bridges on the Seward-Anchorage 

and Copper River Highways indicates that there is a correlation between damage and the type of 

bridge. Figure 47 is a chart showE 

Severe or destroyed 

603-6041 

605-606 

~ 

603-605-606-621-622-623-624-625-626-627- 628- I 629-630-631-632-633-634-635-638-640-641-642 

363-365-] 

366-367 

331-332-206-596-1 

597-598-620-644 

348-349-350- I 351-352-639-643 

406-407-408-409-411-354-334-335-336- I 338-339-340-341-342-344-345-346-329-331 

47.-Chart showing type of bridge, foundation material, and intensity of damage to bridges on Seward-Anchorage and Copper 

River Highways. Numbers are bridge designations (see tables 15, 16). The 200, 300, oand 400 series structures are on the 

Copper River Highwey; the others are on the Seward-Anchorage Highway. Length of bar ~s proportional to number of 

bridges damaged. 
G48 ALASKA EARTHQUAKE, MARCH 2 7, 19 64 

ing type of bridge, foundation material, and intensity of damage to 

bridges on the Seward-Anchorqe 

and Copper River Highways. 

The most significant engineering fact that the chart shows is the 

relation between the superstructure and substructure. During the 

construction of 22 of the bridges 

on lthe Copper River Highway, 

Copper River and Northwest Railway rails were used as piles. Three 

of these rails, believed to 'be 50- 

pound rails were welded with their 

heads together. They were then 

driven, and when a bent was completed the rails were cut off and a 

concrete cap placed upon them. At 

some places, steel sway braces were 

welded on the rails. Where icing 

of @he creek would present a problem, concrete curtains were placed 

between the rails (fig. 40). These 

rails are brittle, and one of the 

techniques track-layers used to cut 

off a rail was to first mark it with 

a chisel and then strike the rail 

sharply with a hammer. The rail 

would break at 'the chisel mark. 

During bhe driving, the welded 

rail piles were occasionally broken. 

When the earthquake struck, all 

except two (Scott Glacier 10, mile 

10.8, and Copper River 14, mile 

37.5) of the bridges whose bents 

consisted of rail piles were moclerately or severely damaged or were 

. destroyed. The rail piles were 

broken above the waterline in most 

of the structures that did not have 

a concrete curtain. In those that 

had concrete curtains, failure of 

the piles generally occurred below 

the waterline. Figure 39 shows 

results of such a f a1 '1 ure. 

significant comparison between all-wood bridges and 

bridges with concrete superstmcture and wood substructure can 

also be made. For example, a remarkable difference in damage intensity can be seen if we compare 

the all-wood structures on the 

48.-Korth abutment of Copper River 9 bridge, 338, mile 36.1, Copper River Highway, showing displacement of deck laterally to the left relative to substructure. 

Photograph by George Plafker. 

Copper River Highway with the 

concrete and wood bridges on 

the Seward-Anchorage Highway, 

negleoting for a moment the geologic conditions. Most of the all1%-ood bridges were only slightly 

damaged whereas most of the concrete and wood bridges were severely damaged or destroyed (fig. 

47). If we now take into account 

the geologic factors, the comparison becomes more complex. The 

Tunlagain Arm bridges were 

definitely in a more geologically 

unfavorable environment. The extent to \~-hich this unfavorable environment mould have affected 

all-wood highway structures is unknown. However, on the basis of 

the types of damage to concrete and 

mood bridges, all-concrete bridges 

(on Portage Glacier Road), and 

all-wood bridges caused by the 

earthquake, it is proposed that if 

the superstructure was relatively 

heavier than the substructure, the 

bridge was more severely damaged. If the deck is heavier than 

the substructure, the tie between 

them is more easily broken because of differential movement of 

the two units by seismic shaking. 

When this movement occurs, the 

substructure and superstructure, 

in effect, become independent of 

one another and, instead of reinforcing one another they actually compound the effects of 

seismic shaking. Figure 48 is a 

photograph looking south at 

Copper River 9 bridge, 338, mile 

36.1, on the Copper River Highway. The deck of the structure apparently had a seismically induced 

motion independent of the substructure and actually destroyed 

the top of much of the north abutment. Note that the final position 

of the superstructure indicates 

that the deck was displaced to the 

east relative to the abutment and 

the remainder of the substructure. 
The earthquake of March 27, 

1964, caused $46,798,29·2 worth of 

damage to the highway system in 

south-central Alaska. Damage 

was caused by seismic shaking, 

seismic sea waves, and regional 

tectonic subsidence. The table summarizes the effects associated with 

these three major causes of damage. Seism-ic shaking and the 

effects associated with it apparently caused the most damage. The 

effects of the Alaska earthquake 

upon the 11ighway system once 

again demonstrated the significant 

fact that structures on bedrock 

were not damaged as much ·as 

those on sediments. 

J!lj]ccts on highwa11 s11stem, ca-!tsed b11 

seismic sha,J,;ing, seis1nic sea waves, and 

1·eg·ional tectonic subsidence b11 the 

AZas1ca ea,rthqna1cc 

Seismic shaking 

Lateral displacement of sediments : Subsidence of roadway and bridge 

npprouches 

Eclcel, E. B·., and •Schaem, W. E., 1966, 

in Hansen, W. R., and others, The 

Alaska earthquake, March 27, 1964 : 

Field investlgntlons and reconstruction effort: U.S. Geological Survey 

Professional Paper 541, p. 46-69. 

Ferrinn's, 0. J., Jr., 1966, Effe'Cts of t~he 

enrthqu.nke o·f Mare11 27, 1964, in 

tJhe Oo·pper River Ba:sin a•ren. 

Alaska: U.S. Gool. Survey Prof. 

Puper ·543-E, 'P· El-E28. 

Golub, Hwrvey, 1964, Bridge dnmnge 

report-'mlle 13 to mile 59, Copper 

River Highway-FA'S 851: Alnskn 

Dept. Highways Document. 

EFFECT.S ON THE HIGHWAY SYSTEM 

SUMMARY 

Lateral dlisplacement of sediment~ 

Continued 

Displacement of roadway parallel to 

highway nxis 

Displacement of rondway nonual to 

highway axis 

Displacement of bridge abutments, 

bents, and piers toward center of 

creek 

Displacement of bridge piers and 

bents upstream and downstream 

Placement of bridges in compression 

Formation of fractures : Along roadway centerline 

Along roadway edges or shoulders 

Normal to axis of roadway 

Oblique fractures : Refracted normal to roadway 

Continued through roadway nt 

oblique angles 

Compactions of sediments: 

Fractures in roadway normal to axis 

Fractures along edge "Of roadway 

Subsidence of roadway and bridge 

approaches 

Inundation during high tides 

Wavy roadway due to differential 

compaction 

Landslides : Slides onto roadway 

Slides in roadway: 

Fracture of roadway normal to 

axis 

Fracture of roadway parallel to 

nxis 

Displacement of roadway normal to 

axis 

REFERENCES CITED 

Grnntz, Arthur, Plafker, George, and 

Kachadoorian, R e u b e n , 1964, 

Alarska's Good Friday earthquake, 

Ma-reh 27, 1964, a preliminary 

geologic evaluation: U:S. Geol. 

Survey Circ. 491, 35 p. 

Kachadoorian, Reuben, 1965, Effects of 

the ea·rthquake of Marcb 27, 1964, 

at Whittier, Alaska: U .. S. Geol. 

Survey Prof. Paper 542-B, p. 

B1-B21. 

Migliaccio, R. R., 1966, Earthquake 

dnmage to highways in the Valdez 

diostrict, Alaska: Natl. Reseal"ch 

Council, Highway Research Board, 

Highway Research Rec. 91, p. 

64-12. 

C49 

Landslide~Oontinued 

Slides in roadway-Continued 

Displacement of roadway parallel 

to axis 

Destruction of bridge 

Seismic shock : Damage to bridges : Differential movement of structural 

elements 

Broken tie between superstructure 

and substructure 

Bridge in compression 

Seismic wave in bridges : Vertical movement of bridge during 

shaking 

Horizontal movement of bridge durdng shaking : Displacement of deck upstream or downstream 

Displacement of deck along axis 

of bridge 

Bridge in compression 

Ground waves in roadway 

Avalanches: Upon roadway 

Sand and mud ejecta: In roadway 

Seismic sea waves 

Destruction of bridges : Sweeping away of superstructure 

Destruction of substructure 

Damage to roadway : Scouring of fill 

Regional tectonic subsidence (coupled with 

compaction of sediments) 

Inundation of roadway during high 

tides 

Inundation of bridge sites 

Erosion of roadway by high tides 

Ptafker, George, 1965, Tectonic deformation associated with the 1964 

Alaskan ea,rthquake: 'Science. v. 

148, no. 3678, p. 1675-1687. 

Plafker, George, and Kachadoorian, 

Reuben, 1966, Geolagic effects of 

the Mareih 1964 earthquake and 

n·ssociated rsei·smic sea waves on 

Kodiak and nea-rby i'slands, Alaska : 

U:S. Geol. Survey Prof. ·Pa·per 

543-D, p. D1-D46. 

U.S. Coast and Geodetic Survey, 1966, 

The Prince William Sound, Alaska, 

earthquake of 1964 and aftershocks : Washington, .U .'S. Govt. 

Printing 01fi.ce, v. 1, 263 p. 
.. _ 

'} 
TABLES 3-19 

.,.. 

.' ..... 

•· 

EFFECTS ON THE HIGHWAY SYSTEM 

TAB~J~ 3.-Foundation material and major effects of Alaska earthquake on the roadway of 

Seward-Anchorage Highway 

Milo 

1 to 3 ______ _ 

17 _________ _ 

17 to 20 ____ _ 

33.0 to 33.0 __ 

35 _________ _ 

40.0 to 40.5 __ 

40.4 _____ ---- 41.7 ________ _ 

44.8 to 45.6 __ 46.3 to 46.7 __ 

51.1 to 51.8 __ 

54.5, 54.9, 

55.0, 56.0. 

56.0 t'o 56.4 __ 61.8 to 62.0 __ 63.2 to 64.9 __ 66.8 to 67.2 __ 73.2 to 73.6 __ 

75.0 to 90.5 __ 

92.0 to 93.5 __ 98.5 to 105.5_ 

Foundation material 

Stream sediment ____ _ 

Silt and sand _______ _ 

: ___ do _____________ _ 

Stream sand and 

gravel. Bedrock ____________ _ 

Swamp sediments on stream sediments. ____ do _____________ _ ____ do _____________ _ 

TilL _____ - - - - - - - - - - - Swamp deposits over stream deposits. Fine tilL ___________ _ 

TilL _____ - - - - - - - - - - -

____ do _____________ _ 

Stream sediments ____ _ Fine tilL ___________ _ _ ___ do _____________ _ 

Fill over swamp 

deposits. Tidal sediments _____ _ 

Bedrock ____________ _ 

Tidal silt, sand, and 

gravel. 

Effects of earthquake 

Roadway fractured, wavy; differential com- paction. 

Two-foot slump where road goes onto Snow 

River delta. 

Roadway down as much as 11 feet, horizontally displaced 13% ft. 

Roadway fractured. 

Avalanche from east side of road. 

Roadway wavy; differential compaction of 

sediments. 

Culvert up 1% ft; compacted sediments. 

Avalanche from east side of road. 

Roadway slumped into Summit Lake. 

Roadway wavy; mile 46.6 culvert bent. 

Roadway wavy; maximum subsidence is 6 

in. 

Small slides onto road. 

Roadway fractured, compacted, and wavy. 

Roadway fractured; local subsidence. 

Roadway wavy; subsidence as much as 6 in. 

Roadway fractured; local subsidence. 

Roadway fractured, wavy; subsided 6 in. 

Roadway fractured, displaced vertically and 

·horizontally; maximum compaction of 

4.4 ft plus regional subsidence of 5.6 ft, 

total subsidence of 11 feet; six large ava- lanches between mile 82.5 and mile 87.5. 

Eight large avalanches. 

Roadway compacted, fractured, wavy; inundated during high tides. 

TABLE 4.-Foundation material and major effects of Alaska earthquake on roadway 

of Sterling Highway 

Milo 

39.5 _____ ---- 44.9 _____ ---- 44.9 to 5L __ 60.0 to 60.2 __ 70.5 to 71.5 __ 

74.9 to 76.5 __ 

85.8 ________ _ 

90.0 ________ _ 94.8 _______ _ 100 ________ _ 102 ________ _ 

Homer Spit __ 

Foundation material 

Coarse sediments ____ _ ____ do _____________ _ 

Stream graveL:. __ . ___ _ Till over bedrock ____ _ 

Swamp deposits over till. ____ do _____________ _ 

Swamp deposits over glacial outwash. ____ do _____________ _ _ ___ do _____________ _ 

Lake sediments _____ _ 

Lake silts and sands __ GraveL ____________ _ 

Effects of earthquake 

Slide across roadway. 

Landslide across roadway. 

Roadway fractured, compacted, and wavy. 

Roadway fractured; slide across road. 

Roadway compacted 2-3ft; displaced south · 4 ft; severely fractured, wavy. 

Roadway compacted, fractured, wavy, and 

displaced. 

Roadway fractured, compacted, and wavy. 

Roadway compacted and wavy. 

Roadway fractured, compacted, and wavy. 

Slumps on road. 

Do. 

Compacted, subsided; eroded by the sea. 

C53 
C54 ALASKA EARTHQUAKE, MARCH 27, 1·9·64 

TABLE 5.-Foundation material and major effects of Alaska earthquake on roadway of Glenn Highway 

Mile 

27 to 35 ____ _ 

37 _________ _ 38 _________ _ 

39 to 40 ____ _ 58 to 59 ____ _ 

60.5 to 60.7 __ 

61.0 to 61.2 __ 

63.5 to 65.5 __ 69 _________ _ 

7L ________ _ 74 _________ _ 

78.5 _____ ---- 82.0 to 82.5 __ 

88.5 to 89.5 __ 

97.7 to 98.3 __ 99.0 to 100 __ 

106, 107.2_-- 111_ _______ _ 114 ________ _ 138 ________ _ 

140 ________ _ 

Foundation material 

Swamp deposits _____ _ 

Bedrock ____________ _ ____ do _____________ _ 

Outwash graveL ____ _ Ground moraine _____ _ 

_ ___ do _____________ _ 

Ground moraine and 

stream sediments. 

Terrace gravels ______ _ ____ do _____________ _ ____ do _____________ _ 

Ground moraine _____ _ ____ do _____________ _ 

Outwash gravel _____ _ 

_ ___ do _____________ _ 

Ground moraine _____ _ ____ do _____________ _ 

____ do-------~------ ____ do _____________ _ ____ do _____________ _ ____ do _____________ _ ____ do _____________ _ 

Effects of earthquake 

Roadway compacted, fractured, wavy; locally displaced and inundated during high 

tides. 

Slide across roadway. 

Large avalanche across roadway. 

Roadway slightly fractured and wavy. 

Roadway fractured, compacted, wavy; small 

slide at mile 59. 

Roadway compacted, fractured, and wavy; 

small slide at mile 60.6. 

Roadway compacted, fractured, wavy. 

Roadway fractured and wavy. 

Small slide on roadway edge. Do. 

Roadway slightly fractured. 

Do. 

Roadway compacted, slightly fractured, and 

wavy. 

Roadway slightly compacted, fractured, and 

wavy. 

Roadway fractured. 

Roadway compacted, fractured, and wavy. 

Roadway slid downslope. 

Roadway fractured. 

Do. 

Roadway slid two places. Do. 

TABLE 6.-Foundation material and major effects of the Alaska earthquake on the roadway 

of the Richardson Highway 

Mile 

0 to 6 ____ "' __ 

38 _________ _ 39 _________ _ 40 _________ _ 42 _________ _ 44 _________ _ 

59 to 6L ___ _ 64 to 7 5 ____ _ 

7 5 to 85 ____ _ 

85 to 110 ___ _ 

Foundation material 

Glacial outwash _____ _ 

Bedrock ____________ _ ____ do _____________ _ 

Stream sediments ____ _ Bedrock ____________ _ ____ do _____________ _ 

GraveL ____________ _ 

Glacio-lacustrine sediments. 

Stream deposits, silt 

and clay. Sand and graveL ____ _ 

Effects of earthquake 

Roadway compacted, displaced, fractured, 

and wavy. 

Avalanche. 

Do. 

Landslide. 

Avalanche. 

Rockslide. 

Three avalanches. 

Roadway compacted, displaced, fractured; 

landslide at Tonsina Bridge (mile 66.0) and 

Tonsina Hill (mile 73). 

Roadway fractured; at mile 80, four landslides; at mile 76, water eroding roadway. 

Local fractures in roadway and small stretches 

of wavy road. 

·~ 
T' EFFECT.S ON THE HIGHWAY SYSTEM C55 

TABLE 7.-Analyses of sediments at Snow River Crossing, Seward-Anchorage Highway 

[Analyses by Alaska Dept. Highways. NV, no value; NP, nonplastic] 

Grading analysis: percent passing- Atterberg limits Natural Material Mile Depth 

~ (feet) ~ ~ Ys No.4 No.10 No. 40 No. 0.02 0.005 Liquid 

in. in. in. 200 mm mm limit 

Pebbly sand_ •.••••••••••••.•..••••.••.•.•••.•• 17.3 13-15 100 95 71 18 4 NV 

])0 ••••••••••.•••••••••••.•••••..•....•••••. 17.3 23-25 100 91 78 45 g 0 0 NV 

Sand ••.•••••••.•.••••...••••••.•••••••..•....•• 17.3 43-45 100 98 94 85 73 15 3 1 NV 

Sand-silt ••••.•••.••••••••..•••.••••..••........ 17.3 53-55 100 98 93 88 59 16 6 2 NV Fine sand •••.•••••••••..•••.••••.•••••••••••.•. 17.3 63-65 100 35 8 4 NV Do •.••.•••••••••••.•••...••••••••...•..•.•• 17.3 73-75 100 90 20 5 3 NV ])0 •.•••.•..••••••...•••••.•..•••••.•.•••••. 17.3 83-85 100 98 29 7 4 NV Sand •••••••.•••••••.••.••••••..••....••..••••.. 17.5 2Q-22 100 99 98 96 92 61 11 5 4 NV 

> ~m~~~n~~-~1ec ::::::::::::::::::::::::::::::::: 17.5 5Q-52 100 72 27 g 24 17.5 6Q-62 100 94 54 17 g 25 Silt. •••.•••..••••.•••••••..••••••••..•...••••.• 17.5 7Q-72 100 88 35 12 27 , Sand and silt lenses •••...••••......•...•••..... 17.5 9Q-92 100 76 64 37 12 27 Pebbly sand ••.•••••.•••..•..••••.....•........ 17.6 2Q-22 100 93 84 81 80 78 21 6 3 NV Silt and line sand ••.•••••.•..•.••.•••••....•... 17.6 3Q-32 100 60 14 6 26 Do •••••.••••••••••...•..•...•.•............ 17.6 40-42 100 68 21 4 25 Silt •••••••••.••••••..••••••..•.•..•.•.........• 17.6 6Q-62 100 98 49 16 29 Do •••.•..•••..••••••••.••....••.•....•..... 17.6 7o-72 100 99 64 20 31 ])0 •••••••••••••••..•..••.•.•..........••... 17.6 9Q-92 ''''99 100 66 14 31 Medium sand ••..••••....••••••....•.•...•..... 17.6 1Q-12 100 88 97 66 4 3 1 NV J<'inc sand._ •••••..•••...•........••.....•..... 17.6 2Q-22 100 98 18 5 2 NV 

> Do •••••..••••.••.•..........•.............. 17.6 25-27 100 96 52 19 5 NV Very .fino sand._---- ..••.••.•..•.•.••...••..... 17.6 3Q-32 100 50 13 5 NV 

Silt._ ••••.••••.....••••..•...•..••.......•..... 17.6 40-42 100 92 50 17 NV Do ••••.•••.••••..••••••....•.•••.•••.•••..• 17.6 45-47 100 88 43 13 NV Do ••••.•••.••.•••••.••....•••.........•••.• 17.6 5o-52 100 64 23 NV Do •..••..•.•.••••••••.•..•••.•.......•..... 17.6 55-57 100 98 63 22 NV Do ••••.••••••••••••.•.•....••••.•••..•••..• 17.6 6Q-62 100 98 61 19 NV Do ••••••.•••.••..••.•••....••.•....•••••••• 17.6 65-67 100 68 24 NV Do •.•••••..••••.•••......••••..•.•...•..... 17.6 7Q-72 100 70 25 NV 

Do ••••••••••.••••••..•••••.••••••••.••...•• 17.6 75-77 100 76 31 NV 

])0 •••••..•...•••.•...••.••.......•...•....• 17.6 80-82 100 98 98 98 78 33 NV 

Silty sand ••••.••••••••••.••....••.•.••••.•..... 17.6 85-87 100 gg gg 95 93 81 41 NV .., 

TABLE B.-Analyses of sediments at miles 78..1,., 79, and 80.8 on Seward-A.nchorage Highway 

[Analyses by Alaska Dept. Highways. NV, no value; NP, nonplastic] 

Material Mile Depth 

Grading analysis: percent passingmoisture Plastic content index (percent) 

NP 15 NP 4 NP 16 NP 23 NP 28 NP 24 NP 27 NP 20 NP 30 NP 30 NP 32 NP 27 NP 18 NP 32 NP 34 NP 33 NP 33 NP 40 NP 20.7 NP 26.5 NP 26 NP 24.7 NP 26.1 NP 28.4 NP 24.5 NP 29.5 NP 32.1 NP 25.1 NP. 27.6 NP 25.3 NP 25.9 NP 35.8 

Atterberg limits 

(feet) 1 ~ ~ Ys No. No. No. No. 0.02 0.005 Liquid Plastic 

· Silty sandy graveL ••••••••..•••.•.•••..••.•.•.•••• 

~~%~~t~~l :~~~::::::::::::::::::::::::::::::::::: Do ••••••••••••.•.•.•••••••••..••.•.•.•••••.•••. Donso clayey silt •..•••••••••••••.•••••••.•.....•... Donso sandy silt._ ••••••••.•.••..•.•.••...•........ Compact sandy silt. __ •••••..•.••..•••..••.....•... Donso silty sand._ ................................ . 

... Eg::::::::::::::::::::::::::::::::::::::::::::: 

Do ••• --- •• --~- __ .............................. . Do ............................................ . · Donso sandy silt. __ ............................... . Do ............................................ . Compact sandy gravel. ........................... . Sand and silt lenses .............................. .. 

ComJg~~-~~-o-~~~1-~:: ::::::::::::::::::::::::::::::: 

l)o .. -------.--.. -.------ .. -----------.--------- Donso sandy silt. __ ............................... . Compact plastic silt.. ....•.•...••........•...•.•.•. •silty sandy grnvoL ............................... . Do ............................................ . Silty sand ......................................... . Do ............................................ . Compact silty sand ............................... . Do ............................................ . Do ............................................ . 

· l)o ................ -- .. --------------· ·------··-

78.4 

78.4 

78.4 

78.4 

78.4 

78.4 

79 

79 

79 

79 

79 

79 

79 

79 

79.6 

79.6 

79.6 

79.6 

79.6 

79.6 

79.6 

80.8 

80.8 

80.8 

80.8 

80.8 

80:8 

80.8 

80.'8 

in. in. in. in. 

15-17 

25-27 

35-37 

55:-57 75-76.5 

85-86.5 15-17 

25-27 

35-37 

45-47 

55-57 

65-66.5 75-77 85-86.5 

15-17 100 93 83 78 25-27 100 35-37 100 98 94 45-47 100 55-57 100 65-67 

80-82 

1Q-12 100 88 79 2Q-22 100 gg 96 3Q-32 100 4<>=42 100 5Q-52 

6Q-62 

7Q-72 

78-80 

4 10 40 200 mm mm limit index 

47 24 4 66 25 5 83 49 13 98 83 22 100 97 94 

100 

100 94 72 66 65 27 4 69 21 4 3 1 0 35 24 10 gg 92 87 89 83 55 29 8 74 ---·:Nv 3 NP 98 93 66 53 21 .NP 85 75 42 5 NV NP 94 76 26 5 NV NP 98 96 84 31 NV NP 100 gg 97 53 12 22 NP 100 gg 84 43 NP 61 44 16 4 NV NP 83 56 18 4 NV NP 96 82 32 6 NV NP gg 98 81 20 NV NP 100 97 47 16 NV NP 100 81 31 22 NP 100 68 34 NV NP 100 80 42 22 NP 
C56 ALASKA EARTHQUAKE, MARCH 27, 1964 

TABLE 9.-Analyses of sediments at miles 84.2, 86.6, 89.6, 90.0, and 90.4 on Seward-Anchorage Highway 

[Analyses by Alaska Dept. Highways. NV, no value; NP, nonplastic] 

Material Grading analysis: percent passing- Atterberg limits 

Mile Depth 

(feet) ~ ~ % No. No. No. No. 0.02 0.005 Liquid 

in. in. in. in. 4 10 40 200 mm mm 

Dense sandy graveL _______________________________ 84.2 1Q-12 100 87 69 50 32 15 3 1 

DO--------------------------------------------- 84.2 2Q-22 87 82 70 64 50 32 13 6 Layers silt and sandy graveL .. ----------------- ___ 84.2 3Q-32 100 90 86 77 60 39 17 11 

DO--------------------------------------------- 84.2 4o-42 100 99 89 83 69 57 45 37 4 

DO--------------------------------------------- 84.2 45-47 100 95 87 81 78 63 5 

DO--------------------------------------------- 84.2 55-57 100 94 85 76 56 38 23 9 Silt, gravel clay ____________________________________ 84.2 65-67 100 99 80 10 

DO--------------------------------------------- 84.2 75-77 100 95 85 78 61 35 17 8 

DO--------------------------------------------- 84.2 85-87 100 97 94 92 82 72 10 46 8 Sandy (fill) graveL .. ______________________________ 86.6 15-17 Silty graveL _______________________________________ Do 86.6 25-27 89 80 62 57 45 29 12 7 _____________________________________________ 86.6 4o-42 82 69 65 58 41 23 9 5 Silty sandy graveL ________________________________ 86.6 5Q-52 93 83 73 67 52 30 14 7 

DO--------------------------------------------- 89.6 7Q-71 100 74 65 55 35 16 3 1 Do ____________________________ . _________________ 90.0 1'5-17 92 89 74 65 44 25 6 2 Do _____________________________________________ Do 90.0 2Q-22 84 84 82 73 41 15 1 0 _____________________________________________ 90.0 3Q-32 100 93 76 67 48 31 17 5 Silty sand with gravel and clay ____________________ 90.0 4o-42 100 97 94 83 61 20 8 

DO--------------------------------------------- 90.0 5Q-52 93 88 72 65 47 31 12 5 Silty sandy graveL .. ______________________________ 90.0 65-67 86 71 61 58 40 22 6 2 

DO--------------------------------------------- 90.0 8Q-82 100 84 72 61 44 27 11 5 Do _____________________________________________ 90.4 15-17 100 100 84 75 55 34 17 8 

Silty clay _______ ..• ___ . __ . __ -.. ----. ___ ------------ 90.4 2Q-22 100 26 Do _____________________________________________ 90.4 3Q-32 100 83 

Silty clay with sand ___________ --------------------. 90.4 4o-42 100 99 94 46 Do _____________________________________________ 90.4 5o-52 100 87 13 Silty clayey sand ___________________________________ 90.4 65-67 100 67 12 

DO--------------------------------------------- 90.4 8Q-82 100 96 89 86 72 53 20 4 

TABLE 10.-Analyses of sediments underlying Copper River Highway 

[Analyses by Alaska Dept. Highways. NV, no value; NP, non plastic] 

Grading analysis: percent passing- Atterberg limits 

Boring and 

sample Depth Moisture Specific 

Mile 

14.8 

14.8 

15.1 

15.8 

15.8 

15.8 

15.8 

16.0 

16.5 

16.7 

17.4 

17.4 

17.4 

18.2 

18.2 

18.6 

18.6 

(feet) 3in. No.10 No. 40 No. 200 0.02 0.005 Liquid Plastic content gravity No. mm mm limit index (percent) 

TH 3 5-7 100 35 20 8.0 4.4 2.1 NV NP 4.2 TH 3 9-10 100 72 54 19.9 8.1 3.6 NV NP 14.3 TH 5 1Q-13 lOO 44 23 4.1 2.2 1.1 NV NP 6.8 TH 15 3~-4~ 100 8 3 .4 .3 .2 NV NP 1.3 

TH15 8-9~ 100 78 68 35.6 11.2 2.9 NV NP 23.5 TH 15 13-14~ 100 97 90 47.3 14.9 3.8 NV NP 34.1 TH 15 18-19 100 97 95 85.3 48.9 20.7 27 NP 48.4 TH 19 3-4~ 100 100 89 33.6 10~3 2.4 NV NP 29.7 TH24 5-7 100 42 26 15.2 9.3 5.1 23 NP 13.2 

TH34 4-5 100 37 21 14.1 10.3 6.0 22 6 5.1 

TH38 3-4~ 100 89 77 29.0 11.1 3.5 NV NP 26.2 

TH38 8-9~ 100 70 49 24.2 13.4 5.4 NV NP 36.1 

TH38 13-14~ 100 70 56 9.8 3.3 1. 2 NV NP 17.1 

TH46 1-3 100 39 20 8.1 5.2 2.8 NV NP 3.3 

TH46 11-12 100 67 56 35.5 19.0 7.6 17 NP 15.1 

TH50 2-4 100 43 23 11.4 7.9 4. 2 NV. NP 3.2 

TH50 11-13 100 48 23 5. 7 3.4 1. 8 NV NP 8.5 

TABLE 11.-Analyses of sediments on Richardson Highway from mile 1.00 to mile 2.78 

[Analyses by Alaska Dept. Highways. NV, no value; NP, non plastic] 

Boring Grading analysis: percent passing- Atterberg limits Moisture 

Mile and Depth content sample (feet) 3in. No. 10 No. 40 No. 200 0.02mm 0.005mm Liquid Plastic (percent) No. limit index 

1.03 TH 1 8 100 84 72 42.4 24.6 10.2 NV NP 18.0 

1. 03 TH 1 18 100 63 40 16.0 9. 0 5.0 NV NP 12.5 

1. 28 TH 2 7 100 36 20 8. 7 6.6 3.4 NV NP 2.8 

1.28 TH 2 13 100 56 31 15.7 11.0 5.6 NV NP 13.2 

1.28 TH 2 19 100 54 40 22.1 13.5 6.1 NV NP 13.4 

1.52 TH 3 15 100 47 28 15.9 10.4 5. 7 16 NP 3.8 

1. 52 TH 3 29 100 48 27 14.1 10.0 5.8 NV NP 5.6 

1. 73 TH 5 16 100 46 24 8. 6 6.0 3.9 NV NP 3.6 

1. 73 TH 5 25 100 52 18 5.3 3.8 2. 7 NV NP 9.8 

1.82 TH 6 12 100 83 66 34.5 18.5 7.4 NV NP 25.3 

1.82 TH 6 25 100 95.4 86 52.7 23.6 8.8 NV NP 26.2 

1.82 TH 6 33 100 90.3 77 38.6 19.0 8. 0 NV NP 24.0 

2.08 TH 8 5 100 21.4 10 5.3 3.5 2. 0 NV NP 1.6 

2.08 TH 8 18 100 64.3 37 6. 6 4. 7 3.0 NV NP 12.1 

2. 08 TH 8 25 100 92 80 39.2 23.6 11.1 NV NP 29.7 

2. 08 TH 8 28 100 67 30 10.2 7. 4 3. 7 NV NP 15.0 

2.31 TH 10 28 100 63 31 9.3 6. 2 3.4 NV NP 12.8 

2. 56 TH 12 15 100 50 30 15.6 8. 5 4.4 NV NP 9. 5 

2. 56 TH 12 32 100 58 28 9.4 5. 7 2. 7 NV NP 13.7 

2. 78 TH 14 15 100 81 52 16.8 10.1 5.8 NV NP 8.2 

2. 78 TH 14 22 100 73 64 31.7 14.4 6. 6 NV NP 14.0 

2. 75 

2. 73 

2. 74 

2. 71 

2. 70 

2. 69 

2.65 

2. 73 

2. 73 

2. 74 

2. 73 

2. 74 

2. 73 

2. 71 

2. 70 

2. 74 

2. 73 

limit 

NV 

NV 

NV 

24 

24 

NV 

22 

NV 

24 

NV 

NV 

NV 

NV 

NV 

NV 

NV 

NV 

NV 

NV 

NV 

NV 

24 

50 

27 

28 

23 

NV 

Plastic 

index 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

NP 

11 

NP 

NP 

NP 

NP 

~ 

~ 

·"!( 

• 
... 

... 

EFFECTS ON THE HIGHWAY SYSTE·M 

TABLE 12.-Correlation of foundation material of roadway and fractures of SewardAnchorage Highway from mile 75.1 (Ingram Creek) to mile 95.0 

Milo Foundation material 

75.1 to 77.1__ Silt, sand, and fine 

gravel; water table 

generally within 3 

ft of surface. 

77.1 to 78.4__ _ ___ do _____________ _ 

78.4 to 81.0__ Silt, sand, and fine 

gravel; water table 

generally within 2-3 

ft of surface. 

81.0 to 82.6_ _ Silt, sand, and sandy 

gravel; water table 

within 4 ft of sur- face. 

82.6__ _ _ _ _ _ _ _ Bedrock for 150 ft_ __ _ 

82.7 to 84.9__ Coarse sand and 

sandy gravel; 

water table more than 6 ft from sur- face. 

84.9 to 84. 95_ Bedrock ____________ _ 

84.95 to 86.6_ Coarse sand and 

sandy gravel. 

86.6 to 87 .8_ _ Tal us .over bedrock __ _ 87.8 to 87.9__ Swamp deposits over bedrock. 

87.9 to 88.9__ Bedrock ____________ _ 

88.9 to 91.0__ Tidal silt and sand; 

water table close to 

surface locally, es- pecially at Girdwood. 

91.0 to 95.0__ Veneer of glacial outwash less than 10ft 

thick overlying 

bedrock . 

Extent and nature of fractures 

Fractures normal to and along edge of roadway; normal fractures, spaced about 75 

ft apart, have vertical displacement of as much as 6 in.; fractures along edge are as much as % mile long, 6 in. wide, with 

north or downslope side down as much as 6 inches. From mile 76.4 to mile 76.9, 

fractures about 10Q-125 ft apart. 

Fractures normal and along edge of roadway, but larger than those from mile 75.1 

to mile 77.1; fractures refracted normal 

to roadway, cross roadway, and then con- tinue on original heading. Have vertical 

displacements as much as 6 inches, horizontal to 1 ft. 

Heavily fractured; fractures normal to roadway, along edges, and in center of roadway; largest fracture occurred in this 

section of roadway (figs. 12, 13). 

Fractures normal or perpendicular to roadway may have 4 feet horizontal displacement and 1 foot vertical; spaced 100 to 

150 feet apart. Maximum width of fracture in center of roadway 10 ft, length 

500 ft depth 6-8 ft. 

Series of fractures normal or perpendicular 

to highway spaced 20Q-250 ft apart with 

horizontal displacement to 6 in. and 

vertical displacement to 4 in.; fractures 

along edge of roadway, although not as extensive as those from mile 77.1 to mile 

78.4. 

No fractures; fill at each end fractured at 

contact. 

Fractures, normal to roadway, occur as series 

locally spaced 75-100 ft apart; series are at miles 82.8-82.9, 83.2, 84.1-84.2; at mile 

84.2-84.9, single fractures normal to highway spaced 400-500 ft apart; very little 

displacement on fractures in this section 

of roadway. 

No fractures; fill at each end fractured and 

compacted; displaced vertically 3-3~ ft. 

Series of small fractures normal to roadway; no displacement; bedrock from mile 

85.6 to mile 85.7. 

No fractures. 

Closely spaced fractures normal to roadway; 

displacement slight b~cause swamp deposits shallow. 

No fractures. 

Small fractures normal to roadway and 

locally along edge of roadway. Only slight 

horizontal displacement in normal 

fractures. 

No fractures . 

C57 
C58 ALASKA EARTHQUAKE, MARCH 27, 1964 

TABLE 13.-Bridges in south-central Alaska severely damaged or destroyed by the Alaska 

earthquake 

[Only primary and secondary highways listed; streets and bridges in communities not included] 

Number Length Severely damaged or destroyed Highway or road 

of bridges (feet) Number Length Bridges Length of bridges (feet) (percent) (percent) 

Copper River Highway ______ 53 14,208 32 12,015 60 85 

Edgerton Highway _________ 4 642 0 0 0 0 Glenn Highway ____________ 21 5,000 1 2,006 5 40 Hope Road ________________ 2 200 0 0 0 0 

Kenai-Nikiska Road ________ 1 75 0 0 0 0 

Portage Glacier Road _______ 3 279 3 279 100 100 

Point Whitshed Road _______ 5 374 1 100 20 27 

Richardson Highway ________ 20 2, 739 2 231 10 8 

Seward-Anchorage Highway ________________ 54 9,318 30 6,370 55 68 

Sterling Highway ___________ 13 1, 220 2 553 15 45 

Chiniak Highway ___________ 20 1, 700 15 1, 330 75 78 

Anton Larsen Bay Road ____ 4 256 2 83 50 32 

Saltery Cove Road _________ 0 0 0 0 0 0 

Pasagshak Bay Road _______ 3 250 3 250 100 100 

Chiniak Highway-Spruce Cape Road ______________ 1 50 1 50 100 100 

TotaL ______________ 204 36, 311 92 23,267 45 64 

TABLE 14.-lntensity of damage to bridges on primary and secondary roads in south-central Alaska 

[Only primary and secondary highways and roads listed; streets and bridges in communities not included] 

Damage intensity 

Highway or road Number of None Slight Moderate Severe or destroyed bridges Number Percent Number Percent Number Percent Number Percent 

Copper River Highway ______ 53 1 2 16 30 4 8 32 61 

Edgerton Highway __________ 4 3 75 1 25 0 0 0 0 Glenn Highway ____________ 21 10 47.5 10 47.5 0 0 1 5 Hope Road ________________ 2 2 100 0 0 0 0 0 0 

Kenai-N ikiska Road ________ 1 1 100 0 0 0 0 0 0 

Portage Glacier Road _______ 3 0 0 0 0 0 0 3 100 

Point Whitshed Road _______ 5 4 80 0 0 0 0 1 20 

Richardson Highway ________ 20 12 60 3 15 3 15 2 10 

Seward-Anchorage Highway __ 54 15 28 6 11 3 6 30 55 

Sterling Highway ___________ 13 8 62 3 23 0 0 2 15 

Chiniak Highway ___________ 20 5 25 0 0 0 0 15 75 

Anton Larsen Bay Road _____ 4 2 50 0 0 0 0 2 50 

Saltery Cove Road __________ 0 0 0 0 0 0 0 0 0 

Pasagshak Bay Road ________ 3 0 0 0 0 0 0 3 100 

Chiniak Highway-Spruce Cape ____________________ 1 0 0 0 0 0 0 1 100 -- TotaL _______________ 204 63 31 39 19 10 5 92 45 

Damage total 

Number Percent 

52 98 

1 25 

11 52.5 

0 0 

0 0 

3 100 

1 20 

8 40 

39 72 

5 38 

15 75 

2 50 

0 0 

3 100 

1 100 -----

141 69 

.... 
)-

~ 

""' 

'r' 

.. 

... 

EFFECTS ON THE HIGHWAY SYSTEM C59 

TABLE H5.-Damage to bridge approaches and bridges (except Allen River bridge) along the Copper River Highway 

[Designations west and cast arc used to Indicate direction from Cordova (mile 0) to Bridge 332, Copper River 3 (mile 27.9) respectively. South and north designation is used 

from mile 33.0 to Million Dollar Bridge (mile 49.0); south and east is toward Cordova, north and west toward Chitina. Numbering of spans and bents runs west to east from milo 0 to mile 27.9 and south to north from mile 33.0 to Million Dollar Bridge. All displacement of spans is measured in relation to movement from original position or bearings on substructure units. Abbreviations used for structure and deck types are (structure type first, deck type second): PCG, prestressed concrete girder; PCS, 

prestressed concrete slab; SA, steel arch; SS, stcc.I stringer; S'l"l', steel through truss; TTS, treated timber stringer; TS1 timber stringer; LT, laminated timber; TP, timber 

plank; H.C, reinforced concrete; prefix '1', preservative-treated material; suffix R, running plank. Bridge number ana name and route mileage from Alaska Dept. Highways, Bridge Inventory Hating Hcport, 1964. Length and superstructure data primarily from Alaska Dept. Highways, Bridge Inventory Rating Report, 1964, supple- mented by U.S. Ocol. Survey data. Bridge damage data from U.S. Geol. Survey and Alaska Dept. Highways] 

Bridge 

No. Name 

381 Eyak Hlvcr _______ 

348 Scott 0 lacier 1 •• __ 

349 Scott 0 hlclcr 2 •.. _ 

350 Scott 0 lacier 3. _. _ 

351 Scott Glacier 4 •... 

352 Scott 0 lacier 5 •.•. 

406 Scott 0 lacier 6 .••. 

407 Scott 0 lacier 7 ••. _ 

408 Scott 0 lacier 8 ••.. 

409 Scott Glacim· 9 •• __ 

410 Scott Glacier 10. __ 

411 Scott. 0 lac lor 1 L __ 

361 Sheridan Glacier 

2. 

230 Sheridan 0 laclm· 

3. 

363 Sheridan Glacier __ 

364 .... do _____________ 

365 .•.. do ........ ·----

366 ...• do _____________ 

367 .... do ..•....•..... 

nouto 

miloago 

5.9 

7.6 

7. 7 

8.2 

8. 6 

9.2 

9.5 

9.8 

10.1 

10.4 

10.8 

11.0 

14.8 

14.9 

15.3 

15:8 

15.9 

16. 1 

16.5 

Length Type 

Ft In. Super- Substructure structure 

225 0 PCS Concrete abut- ments. 150 0 SS, RC Wood piles _______ 

200 0 SS, RC ____ do ____________ 

150 0 SS, RC .... do ____________ 

75 0 SS, RC ___ .do •.... _______ 

75 0 SS, RC .... do ____________ 

375 0 SS, RC Railroad ralls 

welded to- gather. 

175 0 SS, RC .... do ____________ 

151 2 SS, RC .... do ____________ 

75 8 SS, RC ___ .do ____________ 

75 8 SS, RC __ .. do ..... _______ 

352 6 SS, RC . __ .do ____________ 

151 8 TTS,TLT Wood piles _______ 

201 4 PCG,RC Stool casing plies. 

201 8 TTS,TLT Wood piles _______ · 

26 8 TTS,TLT ___ .do ____________ 

39 8 TTS,TLT ___ .do ..... _______ 

27 8 TTS,TLT .... do ____________ 

50 0 TTS,TLT .... do ____________ 

Foundation 

material 

Bedrock __________ 

Fine-grained silty sandy gravel. 

. --.do ____________ 

_ ... do ..... ______ . 

.... do ____________ 

___ .do ____________ 

. __ .do ..... _______ 

. __ .do ____________ 

.... do ____________ 

___.do _______ . ____ 

.... do ..... _. _____ 

___ .do ____________ 

__ .. do .... ________ 

___ .do ____________ 

. __ .do. ___________ 

___ .do ____________ 

___ .do ..... _______ 

.... do ____________ 

.... do ____________ 

Approaches 

None ___________________ 

East approach subsided 

3 in.; west approach subsided slightly. 

Approaches subsided 

unknown amount. 

Unknown .. ____________ 

West approach subsided 

about 10 in.; east 

:~~~~a:f~n~ubsided 

Unknown ______________ 

East agproach subsided 

and ractured; west 

~PJrr~g;:n ~~~~~?, West approach subsided 

3 in.; east approach unknown. 

West a9proach frac- ture ; east approach subsided unknown amount. East approach subsided 

about 3 in.; west approach subsided 

unknown amount. Both approaches subsided about 1 ft. _ __ .do __________________ 

East approach subsided 

1 ft. West approach subsided about 10 in. 

Both approaches subsided about 8 in. 

West approach subsided 5 in. East 

approach subsided 

about 6 in. 

Both approaches subsided about 6 in. 

Both approaches subsided more than 6 in. 

Both approaches subsided slightly. Both approaches subsided about 1 ft. 

Damage 

Bridges 

None. 

Destroyed. East abutment subsided about 

3 ln. Bent 1: north pile down 3 in., west 8 in. Bent 2: north pile down 2}!! ln., west 8 in. Bent 3: north pile down 1 in., west 2 in. Bent 4: north pile down 4 in., west 5 in. Bent 5: north pile went east 8 ln. Concrete deck raised about 5 in. off 

stringer. Deck moved about 3. in, west and broke concrete bulkhead between 

stringers. Some piles were split due to pounding. 

Severe. East abutment piles driven down as much as 2 in.; center pile moved 4 in. west. Bent 1: north pile down 3 in., two piles split. Bent 2: north pile down 4 in., west 4 in.; No.5 pile split. Bent 4: north 

pile down 3 in., east 3 in. Bent 6: north 

pile down 3 in., east 3 in. Bent 7: north 

pile down 3 in., east 3 in. 

Destroyed. Bridge collapsed over bent 5; 

stringers not resting on piles in several 

places. Destroyed. East end: concrete cap moved 

2 in. east, deck jammed into bulkhead. 

Piles apparently moved beneath the 

bridge toward center of creek; west end or deck collapsed. Severe. Concrete bulkhead between steel 

stringers and tied to concrete cap moved east about 2 ft. Bent 1: stringers moved 

off piles eastward. West end: stringers off 

piles; fell behind piles and down about 

2ft. 

Destroyed. Bridge collapsed over broken 

piles in bents 3, 6-9, 12, and 13. 

Destroyed. Bridge collapsed and 4. Many broken piles. at bents 3 

Severe. East end: compression cracks in 

bulkheads. Bent 2 cap cracked above 

north pile. Ralls cracked in bents 1, 2, 4, 

and 5. 

Severe. Slight break in east abutment. 

Deck 6 in. over abutment bulkhead at west end. Bulkhead cracked. 

Slight. East abutment cracked; west abut- ment slightly cracked. 

Severe. Rail bents broken. East and west abutments broken due to movement of 

bridge deck. Caps on four rail pilings and 

several piles broken, especially in center of bridge. Every bent has some rail 

pilings cracked. Bridge wavy. East end 

steel stringer broken loose and abutment 

bulkhead cracked. 

Moderate. Pile bracing split on bent 3. 

Upstream pile of bent 4 shifted from 

under cap. Timber cap split on bent 5. 

Backing plank on abutment 6 pushed 

away from piles. Span 5 stringers split. Slight. Bnckwall of abutment 1 is broken 

above the bridge seat; slight spalling of 

upstream stringer at abutment 1. Severe . Pile cap at pier 2 split; spans dropped on top of piles. Abutment 1 

crowded, causing buckling of laminated 

deck. 

Moderate. West abutment moved east 2 

in.; east abutment west 4 in.; bridge in 

compression . Severe. Abutment 1 cap is tipped and not bearing on piles; backing plank is tipped back . Severe. Abutment 2 cap has moved off center of piles; two piles nrc split . Destroyed. Span 4 severely damaged; in 

bent 2 the cap is split and downstream 

pile is split. . 
C60 ALASKA EARTHQUAKE, MARCH 27, 1.964 

TABLE 15.-Damage to bridge approaches and bridges (except Allen River bridge) along the Copper River Highway-Continued 

Bridge 

No. Name 

368 Sheridan Glacier_. 

369 .... do ....•........ 

370 .... do ............. . 

371 .... do ____________ _ 

372 .... do ____________ _ 

373 .... do ____________ _ 

374 .... do .• _________ _ 

375 Alaganik Slough_. 

376 .... do ____________ _ 

377 .... do ... ---------

378 .... do ____________ _ 379 .... do ___________ _ 

395 .... do •. _________ _ 

330 .... do ____________ _ 

331 Copper River 2. __ 

332 Copper River 3. _. 

354 Long Island Overflow. 

333 Copper River 4. __ 

334 Copper River 5 ••• 

335 Copper River 6 ... 

Route Length Type 

mileage Ft In. Super- Substructure 

Foundation 

material Approaches 

16.6 51 

16.9 101 

17.4 26 

17.9 39 

18.2 51 

18.3 101 

18.9 101 

19.3 51 

19.8 101 

20.2 151 

20.8 58 21.9 151 

22.3 176 

24.0 42 

27. 1 2, 437 

27.9 f\bout 

800 

33.0 124 

33.9 766 

35.0 1, 576 

35. 6 122 

structure 

8 TTS, TLT Wood piles ...... . Fine-grai11ed silty Approaches subsided 

sandy gravel. unknown amount. 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS,TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

8 TTS, TLT 

0 SS, RC 

.... do____________ .... do____________ West approach subsided 

4 in.; east approach 

subsided very little. .... do ____________ .... do ____________ Both approaches subsided slightly. ____ do ________________ do ____________ West approach subsided 

6 in.; east approach 

subsided very little. ____ do ________________ do ____________ Approaches subsided 

about 4 in. 

____ do .. --------- ____ do.__________ Both approaches subsided about 5 in. 

____ do _______________ do .• --------- Unknown. 

____ do ___________ Silt and sand ___ _ 

____ do.__________ _ ___ do .. ---------

____ do.__________ _ ___ do._.--------

____ do ... -------- ____ do. _________ _ ____ do ___________ West end, bedrock; east end, 

sediments. .... do ___________ Silt and sand ____ _ 

Both approaches subsided slightly. West approach subsided 

and has large fracture 

15 ft from deck; east approach subsided 

slightly. Both approaches subsided slightly. Unknown. 

No damage to west ap- proach; east approach 

subsided 4 in. 

East approach subsided 

4in. 

Concrete abut- ments. 

____ do.__________ Both approaches subsided slightly. 

0 STT, TLT, Concrete piers SS, RC. and welded 

rails. 

Fine-grained silt. East approach subsided 

3 ft; west approach subsided about 3 in. 

0 STT, TLT Concrete piers ........ do ____________ Approaches subsided as much as 2~ ft. 

4 SS, RC Railroad rails .... do............ Approaches subsided 1 

welded together. ft; side of roadway subsided 2 ft; down- stream shoulders subsided the most. 

7 STT, TLT Concrete piers ........ do ____________ Approaches subsided 10 to 12 in. 

0 SS, RC Railroad rails in ____ do ____________ Approaches subsided 

concrete. 4 in. 

0 SS, RC. ___ .... do____________ .... do____________ Approaches subsided 

slightly. 

Damage 

Bridges 

Slight. Change in drainage putting more water under bridge than it can safely 

carry. Bridge in compression; deck 

moved west 4 in.; down 1 in. 

Slight. Change in drainage pattern of area directs more water under bridge and aggravates scour at abutment 5. 

Slight. Deck moved west about 2 in.; 

bridge in compression. Slight. Bridge in compression; west end 

deck moved west 4 in. 

Slight. Cap and backing plank on abut- ment 1 have both moved in relation to piles; bridge in compression about 8 in. 

Slight. Bridge in compression about 8 in.; west abutment moved east 5 in.; east abutment moved west 3 in. 

Slight. Deck moved east about 10 in.; 

bridge in compression. Slight. Bridge in slight compression. 

Slight. Bridge in compression; one pile 

broken. 

Slight. Bridge in compression; deck moved 

2 in. to the east. Slight. Bridge in slight compression. 

Slight. Bridge compressed and curved upstream; damage at east end; deck moved 

2 in. east off of caps. Slight. Damage on east end of bridge; railing clamps broken; bridge in slight com- pression. Moderate. Curbs at east end are broken 

where tied to abutments. All abutment 

backwalls have been spalled and cracked 

by movement of curbs. Curb reinforced 

steel extends into backwalls. Diaphragm concrete has moved away from backwalls. 

Severe. Span 1, a 300-ft through truss, has 

been displaced approximately 22 in. east and 8 in. downstream. Abutment 1 

anchor bolts sheared off or bent out of 

shape. Rollers in roller nests lying flat on their sides. Span 2 displaced 19 in. 

eastward and 5 in. downstream. S_p_an 3 

displaced 25 in. eastward and 1~ in. 

downstream. Piers show sheared or bent 

anchor bolts and some spalllng. Spans 3 and 4 jammed together at pier 4. Several 

broken piles; webwalls cracked on almost 

all bents. Truss spans 22-25 moved west- ward. Abutment 36 tipped back and 

badly cracked. 

Destroyed. Middle pier has disappeared; 

span 1 still hanging from west abutment 

with other end in river; span 2 in river. 

Severe. Abutment 1 backwall cracked and 

spa \led from tied-in curb ends, and anchor 

bolts bent. Pier 2 concrete curb spalled over pier, pier tipped northward; down· stream end is low, pier cap cracked. 

Span 2 slab has separated from beams near pier 2. Abutment 3 backwall has 

been destroyed by movement of super- structure. 

Severe. Pier 2 concrete bolster columns 

cracked; end of deck and curbs of span 2 broken up by movement. Span 1 down- stream bearing rollers lying flat, displaced 5 in. northward, bolts sheared. Spans 2-4 

and piers 3-5 appear to be tipped up- stream. At pier 6 concrete bolster columns 

cracked. Curb ends and top of backwall 

of span 5 broken by movement. Span 6 

rollers at full travel with bolts bent, 5in. 

southward movement. Span 7 anchor 

bolts sheared, displaced 8 in. southward. 

Destroyed. Spans 2-5 and piers 3-5 com- pletely destroyed; span 15 fallen off 

pier 16. 

Severe. Abutment 1 shows backwall and 

curb end cracking. Spans 2, 3, and 4 

show 1 in. northward displacement, shearing bolts on span 2 at pier 3, span 3 at pier 4, and breaking sole plate welds on span 4 at pier 4: The backwall or abutment 5 has been destroyed by the 

northern movement of the steel. 
,A: 

..,.. 

/ 

•· 

EFFECT-S ON THE HIGHWAY SYSTEM C61 

T ABI,J<J 1.5.-Damage to bridge app1·oaches and bridges (except Allen River bridge) along the Copper River Highway-Continued 

13rldge 

No. Nnme 

330 Copper H.lver 7 ••. 

337 Copper H.lver 8 .•• 

338 Copper H.lver 0 .•• 

330 Copper H.lver 10 •• 

340 Copper Hlver 11.. 

341 Copper Hlver 12 .• 

342 Copper H.lvor 13 •• 

343 Copper Hlvor 14 •• 

344 Copper Hlvor 15 .• 

345 Copper Hlvor 10 .• 

340 C \oar Crook ••....• 

Houle 

milo· 

ngo 

35.8 

36.0 

36.1 

36.4 

36.7 

36.0 

37.2 

37.5 

37.8 

38.1 

38.0 

Length Typo Damage 

Ft ln. Super· Substructure 

Foundation 

material Approaches Bridges structure 

282 o ss, no 

182 0 SS, RC 

182 o ss, no 

422 o ss, no 

242 o ss, no 

142 0 SS, RC 

282 0 SS, RC 

122 0 SS, H.C 

272 0 SS, RC 

362 0 SS, RC 

182 o ss, no 

Railroad rails in concrete. Fine-grained silt.. Approaches subsided 

about 3 in. 

Severe. Abutment 1 settled ±1 ft. Backwall cracked and spalled at curb ends· 

Slab and curb cracked over pier 2 owing to abutment settlement. Pier 3 tipped northward, shows severe cracking of 

webwall at downstream pile. Concrete 

cap cracked. Sole plate welds on span 2 are broken; no residual displacement. Pier 4 tipped northward. Webwall 

failed at downstream pile, concrete cap cracked over pile. Span 4 twisted; ex- pansion joint closed at downstream 

curb and open about 3 in. at upstream curb. Pier 5 tipped northward. Spans 4 and 5 are 18 in. off their bearings to the north. Piers 6 and 7 settled and 

tipped downstream. Abutment 8 demolished; superstructure was driven 

through it. .... do ............... do ... ----~---- North approach subsided 3 in.; south 

approach subsided 

Moderate. Abutments cracked by curb 

ends; settled 6± in. Expansion joints opened to fullest travel; joint filler 2 in. material fallen out. . ... do .... ------- ... :do ........... . Both approaches generally subsided 

about 6 in.; at north 

approach 1-ft mound at abutment. 

Severe. Abutment 1 curb cracked and 

spalled. Pier 3 webwall broken at up- stream pile and tipped northward, a pile broken, a cap broken. At pier 4, 

span 3 displaced 4 in. north. At pier 5, 

spans 4 and 5 displaced 6 in. north. At 

pier 6, span 5 displaced 6 in. north and 

expansion joint jammed shut, crushing the deck concrete. Span 6 driven through abutment 7, demolishing it. Abutment 

7 settled about 6 ln. .... do........... • •.. do .... -------- North approach subsided about 2ft; 

south approach subsided about 6 in. 

Severe. Abutment 1 demolished by southward movement of superstructure; 

appears to have settled about 1 ft. Entire 

superstructure displaced southward 18 

in. with respect to piers; shows a definite 

undulation. Abutment 8 moved forward 

with the superstructure and settled 

about 1ft. .... do........... . ... do .... _______ _ North approach subsided, but 18 in. 

mound bulldozed at abutment; south 

approach subsided 

Severe. Fill settled away under abutment 1. Abutment backwall badly cracked at curbs. At pier 2, spans 1 and 2 displaced 7 in. north. At pier 3, spans 2 and 3 

displaced 4 in. south. Piers 3 and 4 

tipped north. Abutment 5 demolished 

by northbound superstructure. 4 in. 

.... do .... ------- .... do .... ________ North approach Severe. Both abutments have settled 

about 1 ft and show backwall cracking and spalling at curbs. At pier 3 the step in the concrete cap is cracked at the 

downstream bearing. Expansion joints 

•... do •......... 

.•.. do .•........ 

.... do .•..•..... 

subsided 2 in.; south 

approach subsided 4 in. 

are jammed shut by a northward move- ment . .... do .•......... Both approaches sub- Severe. Capofpier3iscracked. Pier4 failed 

sided about 6-8 in. completely, dropping spans 3 and 4 into 

the river. Pier 5 tipped southward. Spans 5 and 6 show crimping of their bottom 

flanges due to compression. Abutment 7 

has a cracked backwall . . ... do._......... Both approaches sub- Slight. Abutment 1 shows usual cracking at sided about 3 in. curbs; appears to have settled about 6 in. 

Piers 2 and 3 show slab and curb cracking over supports. At pier 4 the expansion joint is open about 3 in.; joint filler has 

fallen out and bolts are at limit of travel 

in their slotted holes . .... do ........... North approach sub- Severe. Abutment 1 shows backwall damsided 4-5 in.; south age at curbs. Pier 2 has severe webwall 

approach subsided cracking. At pier 4 both spans are dis· 

about 1 ft. placed about 2 in. north, and anchor bolts are sheared. There has been a definite ver- tical displacement in this bridge; pier 4 has probably been uplifted. . ... do ............... do ........... South approach subsided 1~ ft; north ap- proach subsided 3 in. 

Severe. Abutment 1 tipped northward and 

superstructure driven through backwall 

with resultant displacement of .±6ft. Pier 

2 tipped south 4 to 6 in. At pier 3, span 2 is 

.... do ...•...... 

1 in. north of masonry plate. Sole plate welds failed. At pier 4, spans 3 and. 4 are 4 in. north of bearings and 8 in. down- stream. Anchor bolts sheared. Pier 4 

tipped southward. Pier 5 cap cracked at upstream bearing. At pier 6 both spans displaced 4 in. north and 2 in. upstream. Diaphragm bolts are gone. Outwash graveL South approach sub- Severe: Abutment 1 demolished by bridge sided about 3 in.; north going south; also app~ars to have settled. 

approach subsided Pier 2 tipped about 2ft south. ·At pier 3, 

about 1ft. span 2 is displaced 4 in. south. Pier has 

settled. Span 3 is 6 in. south of bearing. Abutment 4 shows usual curb cracking and appears to have settled. 
C62 ALASKA EARTHQUAKE, MARCH 27, 1964 

TABLE 15.-Damage to bridge approaches and bridges (except Allen· River bridge) along the Copper River Highway-Continued 

Bridge Route Length Type Damage 

mile- Foundation 

No. Name age Ft In. Super- Substructure material Approaches Bridges structure 

329 Clear Creek _______ 41.0 182 0 SS,RC Railroad rails in Outwash graveL. s~~t~~ggr~a;r r~'::ik?o~ Severe. South abutment demolished by concrete. southward movement of superstructure 500 ft. Fractures 2 ft about 3 feet. Pier 2 tlfaped northward. 

wide; road subsided Spans 1 and 2 are disp aced 4 ln. south· 2~3 ft. North ap- ward at pier 2. At pier 3 both spans disproach fractured about placed 1 ft northward. At pier 4 both 

500 ft and subsided s~ans are displaced 18 ln. northward; at 1% ft. p er 5 both spans displaced 32 ln. north· 

ward and 6ln. upstream. At pier 6, which 

tipped south the spans are displaced 55 

ln. north and 1 ft upstream. Abutment 7 

demolished by sutEerstructure. Piers 5 

and 6moved latera y. 

·.:: 

206 MllllonDollar 49.0 1,400 0 STT,RC Concrete piers. __ .... do .•... ------ Both approaches sub- Destroyed. Span 4 dropped off pier 4 and is 

Bridge. sided 6-8 ln. in the river. Pier 4is virtually destroyed. Rest of bridge has been damaged and 

shows displacements. 

TABLE 16.-Damage to bridge approaches and bridges along the Seward-Anchorage Highway 

[Abbreviations used for structure and deck types are (structure type first, deck type second): CG, concrete girder; PCG, prestressed concrete girder; SS, steel stringer; TTS --.. treated timber stringer; RFC, rigid frame concrete; SPG, steel plate girder; TS, timber stringer; suffix C, cantilever or continuous bridge; A, asphalt; LTA, laminated 

timber and asphalt; RC, reinforced concrete; TP, timber ~lank. Bridge number and name and route mileage from Alaska Department of Highways, Bridge Inventory Rating Report, 1964. Length and superstructure data pnmarily from Alaska Dept. Highways, Bridge Inventory Rating Report, 1964, supplemented by U.S. Geol. 

Survey data. Damage data collected by U.S. Army and U.S. Geol. Survey] 

Bridge Route Length Typo Damage mile- Foundation 

No. Name age Ft In. Super- Substructure material Approaches Bridges structure 

596 Resurrection 2.9 198 0 SS, RC Concrete piers ____ Stream sediment. Subsided unknown Severe. Abutments cracked; anchor bolts 

River 1. amount. sheared; pier cracked; spans down; piers subsided; span moved south and north. 

Maximum movement on south span as much as 7 ln. north and 2 in. west. 597 Resurrection 2.9 135 6 SS, RC .... do .•. ~ ........ . ... do ......... __ . North approach sub- Severe. Abutments cracked; bridge in 

River 2. sided 16 in. South compression; span moved as much as 

:EE~~~~r!sf~:.ted 8 in. 

598 Resurrection 3.0 185 6 SS, RC .... do _____ ....... . ... do ......... __ . Both subsided several Severe. Abutments cracked; north pier River 3. inches. cracked at base, moved north and out of plumb; bridge in compression; span moved north 4 in., east 2 in.; center span down% in.; anchor bolts sheared. 

599 Clear Creek ....... 3.5 75 0 SS, LTA Concrete abut- Sediments _______ . Unknown._ ......... _ .. Moderate. Bridge in compression. merits. 

600 Salmon Creek ..... 6.5 125 6 SS, RC Concrete piers ____ Sandy graveL ... Slight subsidence, up Slight. Decks moved south about 1 in.; to 3 in. in both slight crack in south abutment; north 

approaches. abutment moved north about 1 in.; 

bridge in compression. 601 Bear Creek ______ .. 7.0 51 8 CG,RC Wood piles _______ .... do ............ North apEroach sub- Slight. North abutme.nt subsided about 

sided a out % in. %in. 

602 Grouse Creek L .. 8.0 39 8 TTS, RC .... do _______ ... __ Stream Fill compacted 3-4 in ___ None. 

sediments. 

741 Grouse Creek 2 ... 9.4 23 8 RFC,A Concrete abut- .. .. do ............ Subsided 3-4 in ____ .... Do. ments. 603 I Snow River L .... 17.3 TS, TPA Wood piles _______ Fi~~Ts~~~~ silt Subsided about 4-6 fL. Severe. Brid~e In compression; deck wavy; deck, in paces, is off cap. 604 I Snow River 2. __ .. 17.6 95 0 TS,TPA ___ .do _____ .. __ ... _ ... do ______ ...... Apgroaches subsided Severe. Roadway bowed u~ in middle; a out 6 ft. Surround- bridge in conwression; dec wavy; deck 

ing sediments settled in places, is o cap. about 12ft. 

605 I Snow River 3. __ .. 17.7 209 0 TS,TPA . .. . do ____ .... _ ... .... do _______ ..... A~g~~~~~ts~~~~~d- Destroyed. Third bent from north end 

did not settle. All others settled as much 

ing sediments as 12ft; 3 spans nearest south end slightly settled about 12 ft. twisted and rolled. 

606 1 Snow River 18.2 1, 471 0 TS, TPA . ~ .. do ............ .... do ............ w:rJ:l~~~~:~b- Destroyed. South end of bridge ~ulled 

Overhead ( 4) 6 in. away from abutment; bridges ghtly 

amount; east ap- canted and wavy. Piles on west side 

proach subsided settled 6 in. to 2 ft lower than east side 

about 18 in. in first 1,120 ft (from south end). For next 100ft, timber bents all canted south 

and offset. Last 225-250 ft (north end) 

completely destroyed; it fell or twisted to ground about 75 ft below, destroying roadway and bents. 

603A Snow River, west 17.1 188 6 PCG, RC . .. . do ............ decks; . ... do _____ ..... __ Under construction ___ . Bridge under construction. No 

channel. piers moved downstream as much as 5 ft and canted. 605 Snow River, cen- 17.7 648 6 ter channel. PCG,RC .... do .. _-------- ____ do .. _________ ___ .do. ________________ Do. 

606 Snow River Over- 18.2 289 2 

head. PCG,RC _ ... do. _________ . ____ do .. _________ .... do. __ ------------ Do. 

607 Yictory Creek ____ 20.0 197 3 sse, RC ____ do .. --------- Fill on bedrock._ Fill subsided 2-3 in_. __ None. 

608 Ptarmigan Creek . 23.5 151 8 CG, RC ___ ____ do ___________ Outwash gravel Fill subsided 4--5 in ____ Do. 

and stream 

609 Falls Creek _______ gravel. 25.0 126 9 CG,RC ____ do. __________ Sediments .• _____ .... do •• _-------------- Do. 

610 Trail River __ ----- 25.5 351 8 CG,RC ____ do .• _-------- ____ do •. _-------- Fill subsided 3-4 in. ___ Slight. Bridge in compression. 
•• 

... 

No. 

611 

1137 

1138 

1189 

612 

613 

614 

015 

616 

617 

618 

619 

620 

621 

622 

623 

624 

625 

626 

627 

628 

629 

630 

631 

632 

633 

634 

635 

EFFECTS' ON THE 'HIGHWAY SYSTEM C63 

TABLE 16.-Damage to bridge approaches and bridges along the Seward-Anchorage Highway-Continued 

Bridge Route 

milo- Length Type 

Name ago }'t In. Super- Substructure structure 

Moose Creek •••••• 32.0 76 8 CO,RC Wood piles _______ 

Quartz Crook ••••• 42.0 22 1 RFC Concrete abut- ments. Summit Creek •••• 42.6 22 1 RFC ____ do •• _-------- Colorndo Creek ••• 45.8 22 1 RFC ____ do. __ ----- ___ CI\Dyon Crook. ___ 56.8 302 0 SS, RC Steel towers ______ 

Dry Gulch Crook. 57.1 120 0 sse, RC ____ do ••. --------

Silvcrtlp Creek •• _ 60.7 86 6 SS, RC Concrete piers._ .. Enst Fork Six 61.6 265 9 SPOC, RC ____ do •. __ -------

Milo Crook. 

Ori\Dito Crook. ___ 63.2 206 3 SS, RC _ ___ do .. __ -------

Spoki\Do Crook •••• 64.9 86 0 BS, Ry Concrete abut- ments. Bertha Crook _____ 65.6 145 0 SS, RC Unknown ________ 

Lyon 1\Dd Tin 67.8 146 0 SS, RC Wood piles _______ 

CI\D Creek. 

Ingram Crook •.••• 75.1 206 0 ss,·Rc Concrete piers. __ 

Muddy Crook_-_. 75.8 375 0 CO,RC Wood piles _______ 

Stoop Creek •••.•.• 75.8 200 0 CO,RC ____ do •. ---------

--- Tidowntor Slough 75.9 176 0 CO,RC ..•• do •. --------- 1. 

Tidewater Slough 76.4 76 0 CO,RC .•• Wood piles _______ 

2. 

Tidowntor Slough 77.0 76 0 CO,RC •••• do ____________ 

3. 

Tidcwntor Blough 77.1 76 0 CO,RC ____ do ____________ 

4. 

Pincer River 1 ••••• 77.9 450 0 CO, RC ...• do ____________ 

Placer River 2 ••••• '78.2 125 0 CO,RC ____ do ____________ 

Placer Uivc_r Main 78.4 600 0 CO, RC ____ do ____________ 

Crossing. 

Portage Crook L .• 79.0 175 0 CO,RC ____ do ____________ 

Portngc Crook 2 •.• 79.6 225 0 CO,RC ____ do ____________ 

Portage Crock 3 .•• 70.6 125 0 CO,RC ...• do ____________ 

Jim's Creek ..••••• 80.3 50 0 CO, RC ..•• do .••......... 

Twcntymllc River. 

80.8 820 0 CO,RC .... do ____________ 

Tidewater Slough 5. 

82.0 140 0 CO,RC .... do ____________ 

Foundation 

material Approaches 

Sediments. _______ Both approaches sub'-

sided 2-3 in. 

Bedrock •• _------ None •• _---------------

•..• do •. --------- ____ do •• _-------------- ____ do •. -·------- ...• do. __ -------------- ____ do _______ ---- Fill subsided ___________ 

Thin veneer of ____ do. __ ----------- ___ sediments over bedrock. 

Bedrock.-------- ____ do ____ ---- _____ ----

Stream deposits __ North approach subsided 6 in. in about 10 

ft fill over stream deposits. South ap- proach subsided 

about 2 in. 

Bedrock •• _------ Fill subsided 2 in ______ Coarse graveL ___ None. _____ ------------

____ do •. --------- .... do .• --------------- ...• do •. _-------- ••.. do •• _--------------

SI\Dd 1\Dd graveL_ Unknown amount _____ 

Silty SI\Dd 1\Dd Enst approach subgravel. sided 14 in., west ap- proach subsided 17 in. 

____ do •• ------- East approach subsided 30 in.; west ap- proach fractured 1\Dd 

subsided 12 in. .•.. do •• ---------· Fill. East approach subsided 38 in.; west ap- ~~ach subsided 21-36 

Silt, sand and Fill. East approach silty gravel. subsided 30 in.; west approach subsided 24 

in. 

____ do ••••••• _____ Fill. East approach subsided 40 in.; west approach subsided 28 

in. .•.. do ____________ Fill. East approach subsided 15 in.; west approach subsided 17 

in. _ .•• do _____ . ___ --- West abutment up about 2 in. West ap- proach subsided 

about 8 in.; east ap-

&:'.oach subsided 16 

.... do ____________ West approach subsided 

;~~ia:dsJ4 a &f. roach •... do ____________ West approach subsided 

7 in.; east approach subsided 22 in. Silty sand ________ South approach subsided 27 in.; north 

~f~~ach subsided 

Sand, Rilt, and 

sandy gravel. 

South approach subsided 18 in.; north 

~f~~ach subsided 

••.. do ____________ South approach subsided 23-42 in.; north 

approach subsided 46 

in. 

Silt, sand, and 

silty gravel. 

South approach subsided 24 in.; north 

approach subsided 

22 in. 

Silty sand and South approach subsandy gravel. sided 21 in.; north 

!'PProach subsided 5 Ill. 

Silt and sand. ___ South approach subsided 45 in.; north 

approach subsided 

9Q-96ln. 

Damage 

Bridges 

Slight, Bridge in compression. 

None. 

Do . Do. 

Slight. 

None. 

Do. 

Slight. 

None. 

Do. 

Do. 

Do . 

Severe. Bridge in compression; abutments 

moved toward center of creek. 

Destroyed. From enst end: 2 piles under 

first 12 spans are split. All bracings split. All piles on east side are canted west. Pi ings under last 3 spans are crushed 

1\Dd spans are collapsed. Bridge bowed 

north; not straight across. Destroyed. Western half of bridge, 4 span buckled 1\Dd canted over split, crushed, or canted piles. 

Severe. Two piles settled with road 1\Dd ar e not supporting bridge. Separations ·of 4 

in. 1\Dd 2 in. between spi\Ds in 2 places; replaced. 

Structure received only slight damag e from seismic shock, but bridge was flooded during high tide and had to b 

replaced. Effects of earthquake therefor are considered severe. Do. 

Do. 

e 

e 

Destroyed. Westernmost spans collapsed over first bent (£ilings crushed); eastern- most 6 spans col apsed over crushed piles. 

Destroyed. East abutment damaged; pilings in center bent crushed and spans collapsed over them. 

Destroyed. Both abutments destroyed; all 

pilings destroyed; many punched through concrete roadway; all spans collapsed. Destroyed. Pilings destroyed; some driven 

up through concrete deck; all spans collapsed. 

Destroyed. Both abutments destroyed; 1\11 

pilings destroyed, spans twisted and 

collapsed, some under water. 

Destroyed. Abutments slightly damaged . Center piles crushed and deck collapsed over them. 

Severe. Abutments slightly damaged; deck 

settled over center bent; replaced. 

Destroyed. North abutment destroyed by fissures. All pilings destroyed, and in 

many places are driven through the con- crete deck. All spans collapsed and under water . Severe. Deck raised on either end and 

bowed down in center. 

1 Numbers 603, 605, nnd 606 have been reassigned to bridges under construction at the time of the earthquake. 604 no longer exists. 
C64 ALASKA EARTHQUAKE, MARCH 27, 1.964 

TABLE 16.-Damage to bridge approaches and bridges along the Seward-Anchorage Highway-Continued 

Bridge Route Length Type Damage mile- Foundation 1---· r-· 

No. Name age Ft In. Super- Substructure material Approaches Bridges structure 

.. 636 Peterson Creek ____ 84.2 126 6 CG, RC Wood piles _______ Sandy graveL ___ South approach subsided 9 in.; north approach subsided 9 in. 

Moderate. Replaced. 

637 Kern Creek _______ 86.6 155 6 SS, RC Concrete piers ____ North, bedrock; South approach down Do. 

south, stream 4 in.; north approach gravel. down 1 in. 

638 Virgin Creek ______ 89.6 100 0 CG, RC Wood piles _______ Silty Destroyed. Both abutments damaged; sand ________ South approach subsided about 3 in.; bridge collapsed over northernmost bent; 

north approach sub- pilings shifted and slightly cmshed under 

sided 6 in. all spans. 639 Glacier Creek _____ 90.0 155 6 SS, RC ____ do ____________ Silty sandy South approach sub- Severe. Both abutments damaged. gravel. sided 6 in.; north 

approach subsided 4 

in. 

640 Tidewater Slough 90.9 120 0 CG, RC ____ do ____________ ____ do ____________ South approach sub- Destroyed. North abutment slightly 6. sided 12 in.; north crushed; south abutment entirely crushed; 

approach subsided bridge collapsed over center bent; 

20 in. piles driven through reinforced concrete. 641 Tidewater Slough 98.3 76 0 CG, RC ____ do ____________ ____ do ____________ _____ do _________________ Awash at high tide. Replaced; damage 7. considered severe. 642 Tidewater Slough 98.9 76 6 CG, RC ____ do ____________ ____ do ____________ South approach sub- Severe. Awash at high tide. 

8. sided 18 in.; north 

approach subsided 

12 in. 

643 Bird Creek ________ 103.8 205 4 SS, RC ____ do ____________ Sand and graveL South approach subsided 12 in.; north 

Severe. 

approach subsided 

12 in. 

644 Indian Creek ______ 105.3 165 6 SS, RC Concrete piers(?)_ ____ do ____________ Unknown ______________ Severe. Bridge in compression. 645 Campbell Creek ___ 125.3 22 0 SS, RC ------------------ ____ do ____________ Approach subsided None. 

about 2 in. 

TABLE 17.-Damage to bridge approaches and bridges along Glenn Highway from Anchorage to Richardson Highway 

[Abbreviations used for structure and deck types are (structure type first, deck type second): SA, steel arch; SPG, steel plate girder; SPT, steel pony truss; SS, steel stringer TTS, treated timber stringer; 'l'S, timber stringer; STT, steel through truss; suffix C, cantilever or continuous bridge; 'l'PA, timber plank with asphalt-wearing surface; 

LTA, laminated timber with asphalt-wearing surface; RC, reinforced concrete. Bridge number and name, route mileage, and superstructure data from Alaska Dept. Highways, Bridge Inventory Rating Report, 1964. Substructure and damage data by U.S. Geol. Survey] 

Bridge Route ---r-·--------1 mileNo. Name age 

417 Ship Creek _______ _ 534 ____ do ____________ _ 

535 Eagle River ______ _ 

536 Peters Creek _____ _ 

537 Eklutna River ___ _ 

538 Goat Creek. _____ _ 539 Knik River ______ _ 

540 Matanuska River_ 

541 Moose Creek _____ _ 542 Eska Creek. _____ _ 543 Granite Creek ____ _ 544 Kings River ______ _ 

545 Chickaloon River_ 

546 Puritan Creek ___ _ 

547 Hicks Creek. ____ _ 548 Caribou Creek ___ _ 

549 Little Nelchina 

River. 

550 Cache Creek _____ _ 

551 Mendeltna Creek. 

552 Tolsona Creek. __ _ 

553 Moose Creek _____ _ 

0. 4 3. 2 13.5 

21.6 

26.0 

36.0 

38. 7" 

46.8 

54.9 

61.0 

62.6 

66.8 

78.2 

89.3 

96.7 

106.9 

137.5 

147.2 

152.7 

172.6 

186.2 

Length Type Damage Foundation 

material ~-----------·--- Ft In. Super- Substructure Approaches 

163 

73 

243 

103 

257 

77 2, 006 

353 

183 

31 

183 

243 

253 

21 

133 

233 

183 

22 

61 

81 

41 

structure 

0 TTS, TPA 

6 TS, LTA 5 SS, RC 

Wood piles _______ Stream sediments_ ------------------------ ____ do ________________ do ____________ ------------------------ Concrete piers ____ Glacial graveL ___ Both approaches subsided 1.).1 in. 

8 SPT, RC ____ do ____________ Bedrock __________ Ten ft of fill; no subsidence. 0 SA, RC____ .... do____________ .... do ____________ None __________________ _ 

0 TS, LTA 

6 STT, LTA 

8 STT, RC 

2 sse, RC 7 SS, RC 2 sse, RC 7 SS, RC 

10 sse, RC 

7 SS, RC 

3 sse, RC 2 SS, RC 

2 SS, RC 

3 SS, RC 

5 SS, RC 

5 SS, RC 

6 SS, RC 

Unknown________ Sediments(?)_____ _ ___ do _________________ _ 

Concrete piers____ Stream sediments_ Both approaches subsided unknown 

.... do ___________ _ 

____ do ___________ _ 

Steel piles _______ _ 

Concrete piers ___ _ ____ do ___________ _ 

.... do ___________ _ 

East abutment, 

bedrock; west abutment, 

gravel. Coarse graveL __ _ Glacial graveL __ _ Coarse graveL __ _ ____ do ____________ _ 

Fill over bedrock_ 

amount. None __________________ _ 

_ ___ do __________________ _ 

Subsided about .).1 in. __ _ ___ do _______ . __________ _ 

Subsided .).1 in._ _______ _ 

Fill subsided about 1 in. 

Steel piles________ _ ___ do ____________ East approach: 10ft fill 

subsided 3 in.; west approach: 6 ft fill over bedrock subsided 1 in. 

Concrete piers____ Bedrock__________ None __________________ _ _ ___ do ____________ .... do ____________ East approach subSteel H-piles _____ Silt, sand, graveL 

____ do ________________ do ___________ _ 

____ do ____________ .... do ___________ _ 

Concrete abutment(?). 

.... do ___________ _ 

____ do ___________ _ 

sided slightly. 

West approach subsided 3 in.; east ap- proach subsided 2 in. 

Both subsided 2 in.; approa~hes on about 

15ft of fill. 

Subsided unknown 

amount, probably not more than 3 in. 

Subsided unknown 

amount, probably not more than 2-3 in. 

Subsided unknown amount. 

Bridges 

Slight. Bridge in compression. ·'( 

Do. 

Slight. Bridge has 5 stringers; all bolts on '- stringers 1, 2, 4 and 5 are sheared; down stream shoe bolt on stringer 3 sheared 

Opened up about 1 in. above first pie from south. 

None. 

Slight. North abutment moved about 2 ink. 

North end shows l-in. tension crac between abutment and bridge. None. 

Severe. Concrete pier cracked and canted 

piers slightly displaced toward cente of creek. 

Slight. Bridge in compression; crack on pier at waterline; west abutment moved east about 1 in. 

None. 

Do. 

Do. 

Do. 

Slight. On east abutment, downstream .. _ sliding shoe broke at weld with stringer 

Slight. Anchor bolts on shoe plates shearedd, 

shoe moved 2 in. west; deck move 2-2.).1 in. (west abutment). 

None. 

Slight. West abutment separated fron 

span about 1.).1 in.; all cracks on abut ment between middle stringers. 

None. 

Slight. Bridge in compression; bottom o both bulkheads moved toward middl 

of stream. Slight. East concrete abutment has smal 

cracks; concrete deck cracked at eas abutment. 

None. 

Do. 
) 

EFFECT.S ON THE HIGHWAY SYSTEM C65 

TABLE lB.-Damage to bridge approaches and bridges along the Richardson Highway from Valdez to Glenn Highway 

(Abbreviations used for structure and deck typos are (structure typo first, deck type second): SPG, steel plate girder; SS, steel stringer; SDT, steel deck truss; ST'l', steel 

through truss; TS, Umber stringer; TTS, treated timber stringer; suffix C denotes cantilever or continuous bridge; LT, laminated timber; TP, timber plank; RC, reinforced 

concreto; prefix T, preservative-treated material; suffix A, asphalt-wearing surface; suffix R, running plank. Bridge number and name and route mileage from Alaska Dept. Highways, l3rldgo Inventory Rating Report, 1964. Superstructure data primarily from Alaska Department of Highways, Bridge Inventory Rating Report, 1964, supple- mented by ~.S. Ooologlcal Survey data. Substructure, foundation materials, and damage data collected by U.S. Geological Survey] 

Bridge Route Length- Type Damage mile- Foundation 

No. Name ago Ft In. Super- Substructure structure materials Approaches Bridges 

554 Valdez Glacier 0.0 134 0 Ti-~PR. Wood piles •...... Glacial Approaches subsided Moderato. West abutment jammed about 1 

Stream 1. sediments. 2-5 in.; roadway ft to west; bridge in severe compression: 

wavy. deck wavy. 

555 Valdez Glacier l.l 210 0 T~~PR. .... do ............ .... do ............ Approaches subsided Moderate.· Seventy-five ft from east end, 

Stream 2. 2-6 in.; roadway bridge has moved downstream about 1 

wavy. ft to 18 ln. Fourth bent from east end, 

downstream pile moved about 4 in. 

Second bent from west end, downstream 

3 in. Fifth bent, 2 center piles moved to east about 3 in. Downstream pile cracked 

through about 3 in. from surface. Sixth 

bent, downstream pile split; middle 2 

.... do ............ piles moved east about 3 in . 556 Valdez Glacier 1.4 190 5 SS, RC •••• Concrete piers .... Approaches subsided Severe. West abutment cracked; displaced Stream 3. 3-61n. west about 18 in., bulkhead down about 

1 ft. First 3 bents from west end in 

tension. East abutment sidewall cracked. 

557 Lowe H.lvor Lower 14.7 254 7 STT, Concrete piers(?). Bedrock .......... None. Slight. South abutment has pushed against Crossing. TLTA. span, and bridge Is in compression . 701 Keystone TunneL 15.8 030 0 TunneL ... sieci ·pites::: ::::: .... do ............ . ... do •................. None. 

558 Lowe River Upper 10.0 193 0 SS, RC ..•• . ... do .•.......... .... do .................. Slight. Bridge compressed and low at each 

Crossing. end. 

550 Sheep Creek ...... 19.0 193 0 SPG,RC •.. Concreto piers •..• Glacial outwash .. . ... do .................. Slight. Anchor bolts, ·north pier, bent 

north. Anchor bolts bent, north abutWood piles .•..... .... do ............ Approaches subsided mont. Bridge may have moved 2 in. 

500 Worthington 20.2 41 0 TTS, None. 

Glacier 1. LTA. 4-5in. 

501 Worthington 30.1 01 6 TTS, .... do ............ .... do ............ Approaches subsided Do. 

River. TLTA. 4-61n. 

562 Cascade Creek .... 35.1 58 0 T~PR. . ... do ............ Silt, sand, graveL North approach sub- Moderate. Piles canted. Some movea downsided slightly. stream about 2-3 in., especially on south 

abutment . 503 Small Crock ....... 35.9 23 0 TS, Wood abutments. .... do ............ ApRroaches subsided None. 

LTA. s lghtly. 

564 Tslna River •...... 37.8 103 8 SDT, Concrete abut- Bedrock .......... .... do .................. Do. 

RC. ments. 565 Stuart Crook .•.... 45.6 81 8 SS, RC ...• Steel H-pilcs ...... . ... do ............ South ap£roach sub- Do. 

sided a out 2ln.; 

north approach subsided about 6 ln. 

566 Boulder Crook •... 51.5 26 8 TTS, Wood abutments. Silt, sand, graveL None. Do. 

TLTA. 

507 Squaw Crook •••.. 54.8 41 5 SS, RC •..• .... do ............ . ... do ............ ApRroaches subsided Do. s lghtly. 568 Little 'l'onslnn 06.0 35 0 TS,TP .... .... do ............ .... do ............ Mound about 2}1 ft Severe. North end moved south about 

River. high; roadway 17-20 in. Stringer 6 .in. by 14. in. split. fractured at both Other stringers are broken or split at approaches. north end. Bridge replaced. · 560 'l'onslna River •... 70.1 255 10 ss~6. Concrete piers(?). . ... do ............ Approaches subsided Norie.' 

2-31n. 

570 Squirrel Creek .•.. 80.4 22 0 TI~A- Wood abutments. . ... do ............ None. Do. 

571 Willow Creek •.•.. 00.7 27 0 TTS, .... do ............ . ... do ............ .... do .................. Do. 

TLTA. 

572 Klutlnn Hlvor ..•. 101.0 242 ll SPOC, Concreto piers(?). . ... do ............ .... do .................. Do. 

RC. 

573 'razlina Hlvcr ..... 110.4 403 2 STL~A- c~~':f~~~t~~s .... do ............ .... do .................. Do. 

piles. 
C66 ALASKA EARTHQUAKE, MARCH 27, 1964 

TABLE 19.-Damage to bridge approaches and bridges along Sterling Highway 

[Abbreviations used for structure and deck types are (structure type first, deck type second): C 0, concrete girder; SS, steel stringer; STT, steel through truss; CMP corrugated metal pipe-multiplate and arch; TS, timber stringer; RFC, rigid frame concrete; suffix C indicates cantilever or continuous bridge; RC, reinforced concrete; LTR laminated timber with running plank; TLTA, preservative-treated laminated timber with asphalt-wearing surface. Bridge number and name, route mileage length and' super- structure data from Alaska Dept. Highways, Bridge Inventory Rating Report, 1964. Substructure, foundation materials, and damage data collected by U.S. Geological 

Survey] 

-

Bridge Route Length Typo Damage 

mile- Foundation 

No. Name ago Ft In. Super- Substructure materials Approaches Bridges structure 

680 Daves Creek ______ 41.3 21 0 RFC Concrete abut- Bedrock __________ 

ments. 

None ___________________ Slight. Bridge in compression. 

676 Quartz Creek _____ 41.7 152 1 CO, RC Concrete piers ____ Thin veneer of Fill differentially sub- Severe. East end moved south relative to fine-grained sided about 1~2 in. middle section and west end moved north 

sediments. on each side of bridge. about 3-4 in. Expansion cracks in deck 

widened about 2 in. 675 Kenai River ______ 48.9 400 1 CG,RC Wood piles _______ Sediments ________ Approaches subsided as Destroyed. Wood piles driven through much asS in. 6-in. reinforced concrete. Bridae collaftsed. 674 Cooper Creek _____ 52.6 67 6 SS, RC Concrete abut- Deltaic sediments Both approaches had Slight. Anchor bolts slip~e ~ ncb. ments. 2 in. slumps. Abutment cracked. Flas ing between 

Kenai River ______ 282 0 SS, RC Steel piles ________ Sediments-terrace None ___________________ bridge and abutment squeezed out. 673 54.1 Under construction. 

gravels. 672 Moose River ______ 84.0 159 0 sse, Rc Concrete piers ____ Sediments ________ Both approaches wavy_ Slight. West abutment and bridge deck 

STT,TLTA Steel piles ________ ____ do ____________ None ___________________ opened 1~ in. 671 Kenai River ______ 97.8 379 9 None. 670 Kasilof River _____ 111.6 273 6 STT,TLTA ____ do ____________ ____ do ____________ _ ___ do __________________ Do. 669 Ninilchik River ___ 137.0 159 2 sse, RC Unknown ________ ____ do ____________ ____ do __________________ Do. 668 Deep Creek _______ 139.0 135 3 SS, RC ____ do ____________ ____ do ____________ ____ do __________________ Do. 667 Stariski Creek _____ 152.0 76 6 TS, LTR ____ do ____________ ____ do ____________ ____ do __________________ Do. 796 North Fork 161.7 32 0 CMP ____ do ____________ ____ do ____________ -~--do __________________ Do. 

Anchor River. 666 South Fork 196.7 80 9 SS, RC ____ do ____________ ____ do ____________ ____ do __________________ Do. 

Anchor River. 

U.S. GOVERNMENT PRINTING OFFICE: 1968 0-281-012 ~;