Historical Restoration Contractors Florida: Historic Preservation Consultants
PRESERVATION OF HISTORICAL BRIDGES IN USA: THE …Astaneh... · PRESERVATION OF HISTORICAL BRIDGES...
Transcript of PRESERVATION OF HISTORICAL BRIDGES IN USA: THE …Astaneh... · PRESERVATION OF HISTORICAL BRIDGES...
3rd International Conference on PROTECTION OF HISTORICAL CONSTRUCTIONS
Lisbon, Portugal, 12 – 15 July, 2017
PRESERVATION OF HISTORICAL BRIDGES IN USA: THE GOLDEN GATE BRIDGE AND THE
ALBION RIVER BRIDGE CASES
Abolhassan Astaneh-Asl*
* University of California, Berkeley, USA e-mails: [email protected]
Keywords: Golden Gate Bridge; Albion River Bridge; Experimental testing; Seismic retrofit; Steel bridges; Timber bridges.
Abstract. The Golden Gate Bridge opened to traffic in 1937, is located between two major and active seismic faults, the San Andreas Fault, capable of creating an M8.3 earthquake, and the Hayward Fault capable of creating an M7.3 earthquake. The bridge is only 16 km from San Andreas and 11 km from the Hayward faults. The main challenges in seismic retrofit of this iconic and historical bridge were: (a) to establish the strengths of the critical components of the bridge; (b) to design seismic retrofit concepts that will enable the bridge to withstand its maximum credible earthquake, and; (c) most importantly, to ensure that the historical appearance of the bridge is preserved. The author of this keynote paper, who has been closely involved with the project, discusses critical aspects of these three important items. The Albion River Bridge has a length of 302 meters, opened to traffic in 1944, and is a fine example of a historical timber bridge and one of the last remaining engineered timber bridges in California. The bridge is located in Northern California about 10 km to the east of the San Andreas Fault capable of creating M8.3 earthquakes. The bridge is currently in very fine condition, however, since 2013, the State Department of Transportation has intensified its efforts to demolish the bridge and replace it with a reinforced concrete bridge. The majority of local residents opposing the demolition invited the author to investigate the condition of the bridge and to assess its seismic safety and needs for retrofit. The paper discusses the results of this investigation and how the efforts helped to register the bridge as a U.S. National Historic Place with the Federal Government.
1 INTRODUCTION
In the United States, the main vehicle to preserve historical buildings, bridges, and other structures is through the use of National Register of Historic Places (NRHP) [1], which is a Federal program of National Park Service of the Department of the Interior [1]. The NRHP is based on the 1966 National Historic Preservation Act passed by U.S. Congress as Public Law 102-575 [2]. In the United States, the National Register of Historic Places is the official list of the Nation's historic places worthy of preservation. Authorized by the National Historic Preservation Act of 1966, the National Park Service's National Register of Historic Places is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect America's historic and archeological resources.[2].”
In order for a property in a State to be on the list of National Register of Historic Places, it has to be nominated by property owner, an agency, a historical society or by any individual by filling out a standard form available at [2, 3] and submitting it to the Office of Historic Preservation of the state that the property is located in. Then the SHPO notifies the property owner of the filing of the application and asks for input and comments. Regardless of how the property owner responds or replies at all, the State Office of Historic Preservation proceeds with the review of the application and solicits public comments on the registration and prepares a case for consideration of the State Historic Preservation Commission. After the nomination is approved by the State Commission, the recommendations are submitted by the
state to Keeper
Currlisted asFigure 1HistoricGolden historicathe historegistereand engenginee
One River Btimber triveted last rem
For aor moreevaluatiarcheolobjects associatNationa“(c) thaor that rsignifica
2 GOL
The cin May kilomettotal sus
(a)
the Nationof the Natiorently, theres U.S. Natio1(a), a majoc Places in Gate Bridg
al registratiorical Civil ed as a Natgineering s
ering, the caof the bridg
Bridge also dtruss structutrusses supp
maining well
Figu
a bridge or e of the evaion is to clogy, enginethat possesstion [2].” I
al Registratiat embody trepresent thant and dist
LDEN GAT
constructionof 1937. T
ters. The totspension br
nal Park Seonal Registee are 95214onal Historior steel suspU.S. How
ge Highwayion. The recWar era Po
tional Histosignificancease of historges that werdiscussed inure with timported on twl-engineered
ure 1: (a) the
building toaluation criteonsider “Teering, ands integrity oIn addition,ion as a Histhe distinctihe work of atinguishable
TE BRIDG
n of the GoThe bridge tal length oridge is 1280
Photo: Ab
Abo
ervice in Wer of Histor4 assets suic Places, 26pension brid
wever, the by and Transcreational aoint Fort, whoric Place ane of the Gorical preservre just regis
n this paper.mber braced wo 4-leggedd timber bri
Golden Gate
o be registereria listed i
The quality d culture is of location, , there are storic Placeive charactea master, ore entity who
GE HISTOR
lden Gate Bspans the G
of the bridge0 meters (4
bolhassan Astaneh‐Asl
lhassan Astaneh
2
Washington, ric Places [2uch as sites,670 of themdge, is currbridge is a sportation Darea around hich is nownd is considolden Gate
vation of thistered as a U. The Albiontowers. The
d concrete midge in Cali
e Bridge, and
red as a Nan [2], whicof significpresent in design, settseven spec
e. The critereristics of ar that posseose compon
RICAL PR
Bridge starteGolden Gate is 2742.3 200 ft.) wit
(b)
h-Asl
D.C. for fi2]. , buildings,
m being bridrently eligib
privately oDistrict and
the Goldenw located undered a U.S
e Bridge, ois bridge is iU.S. Nationn River Brie main rivemoment frafornia, and
d (b) the Alb
tional Histoh states tha
cance in Amdistricts, si
ting, matericific criteririon that is a type, perioess high artients may la
RESERVAT
ed in Januarte Strait whmeters (8,9
th a main sp
final review
bridges, adges. The Gble for the Nowned structhe owner
n Gate Bridnder the GolS. Landmarkone of the included in
nal Historic dge, Figurer crossing c
amed towersmaybe in th
bion River Br
oric Place, iat National Rmerican hisites, buildinials, workmaia that can often appliod, or methistic values,
ack individu
TION EFFO
ry 1933 andhich has a 997 ft.) whipan length o
P
w and listing
nd other prGolden GateNational Recture ownedhad not app
dge, which lden Gate Bk. Due to hmarvels othis paper. Place is the
e 1(b), is priconsists of ts. The bridhe U.S.
ridge
it has to satRegister cristory, archngs, structuanship, feelbe used to
ed to the brhod of cons or that repal distinctio
ORTS
d it opened twidth of ab
ile the lengtof 390 mete
Photo: Abolhassan Asta
g by the
roperties e Bridge, egister of d by the plied for includes
Bridge, is historical f bridge
e Albion imarily a two steel ge is the
tisfy one iteria for
hitecture, ures, and ling, and o justify ridges is truction,
present a on [2].”
to traffic bout 1.6 th of the
ers (1280
aneh‐Asl
Abolhassan Astaneh-Asl
3
ft). The structure has six lanes of car and truck traffic with two pedestrian lanes one on each side of the bridge. Although Joseph Straus was the Chief Engineer of the bridge in charge of its design and construction, Leon Moisseiff is credited with the most graceful aspect of the bridge which is its single suspension span. Charles Alton Ellis was the main engineer of the bridge and Irving Morrow designed the architectural aspects of the main towers. The stunning suspension concept of the bridge designed connecting the north side of the San Francisco to the Marin County to the north.
Even before the design of the Golden Gate Bridge started, historical preservation was a major consideration. The alignment of the bridge was passing over the Fort Point, which is a fort built before the Civil War between 1853 and 1861, more than 70 years before the construction of the Golden Gate Bridge started. Currently, the Fort Point is a U.S. National Historic Landmark. At the time of design of the Golden Gate Bridge, an arch bridge was designed over the Fort Point, Figure 1(a), to cross over the historical building.
2.1 Structure of the Golden Gate Bridge and its current condition
The Golden Gate Bridge, shown in Figure 1(b) on the previous page, consists of three distinct segments: the San Francisco approach structures, the Marin approach structure and the main suspension bridge. The two main towers of the suspension spans consist of two multi-cell steel tower legs connected to each other by horizontal trusses above the deck and cross bracings below the deck. The cross-section of the towers is formed with 1 meter (3-1/2 ft) square cells and the base of each leg is 15 cells long and nine cells wide. The cell walls at the base of the tower are 22mm (7/8 inch) thick silicon steel plates. As the tower approaches the top, the cross-section is reduced by reducing the number of cells until only 21 cells remain at the top. At the top of the towers, the suspension cables pass through a cable groove on the saddle. The cables are tied down to the concrete pylons at each end and are connected to the anchorages. The suspended bridge is connected to the shore by two approach structures. The Marin approach has a series of five 53.4-meter (175 ft.) deck truss spans supported on high, four-legged steel towers. The San Francisco approach has one two-hinged arch over the historical fort, two 38.1-meter (125 ft.) deck truss spans supported on two steel towers, one 53.4-meter (175 ft) deck span, and three 21.7-meter (71 ft.) plate girder spans.
2.2 Seismic response of the Golden Gate Bridge and seismic retrofit needs
The Golden Gate Bridge being a long period structure is particularly sensitive to two phenomena: (a) the near-field velocity pulse [4], and (b) the long period component of the far-field strong motions [5]. The first phenomenon, the near-field velocity pulse, results in permanent displacement at the site of the structures located near the ruptured fault. Due to velocity pulse, larger forces and displacements can be generated in the structures [4]. However, this phenomenon is not currently considered in the seismic design of bridges. The second and equally important phenomenon is the effect of long distance earthquakes on long period structures, such as the Golden Gate Bridge. This phenomenon also is not generally considered in the seismic design.
In recent years, the author has undertaken several projects [5], focusing on studying the effects of long-distance earthquakes on long-span bridges and tall buildings, both having long periods of vibration. When a fault ruptures, the ground motion moving away from the ruptured fault becomes weaker but its period of vibration is elongated. When the long period surface waves arrive at the site of a long period structure such as the Golden Gate Bridge, even though the amplitude of the ground motion is relatively small, because of its period is close to the period of the structure, the response of the structure can be quite large. Figure 2
shows fvibratiomotion ground 1999 Chfar fromcompon
Figurquake (left plotweak Cstrongerearthquafar moreNorthridside of weaker Northridindicate
first two moon of 17.5 an
records, onmotion, wihi-Chi-002
m the epicennents of each
FigNo
re 4 shows(Northridge t shows that
Chi-Chi earr Northridgake indicatee damage indge earthquFigure 4 sChi-Chi qudge earthqued that in d
odes of vibrnd 9.5 seco
ne, the 1994ith maximumground mo
nter. Figureh earthquak
Figure(b)
gure 3: Accelorthridge New
s the respon–Newhall)
t the transvrthquake, isge earthquakes that this n the bridgeuake, with Mhows the a
uake createsuake. The stdesign and
(a)
Abo
ration of thonds respect4 Northridgm peak gro
otion, with ae 3 shows tike.
e 2: (a) Two ) ground mot
leration recorwhall, and (b
nse of the and the w
verse displacs about fouke ground relatively we especiallyMPGA of
axial force gs almost thetudy of the evaluation
Tran
Defl
T1 = 1
lhassan Astaneh
4
he Golden Gtively [5]. Tge Newhall ound acceleran MPGA oime history
higher modetions used in
rd of a horizb) the 1999 C
Golden Gaeak but loncement of thur times thmotions.
weak earthqy in the expa0.60g can cgenerated i
e same axialGolden Gaof these b
nsverse
lection
17.5 sec.
h-Asl
Gate BridgeThe structur
records, Firation (MPGof only 0.08y of accelera
es of vibration the analysis
ontal compoChi-Chi-002
ate Bridge tng-period eahe bridge m
he displacemThe larger
quake, with ansion jointcause. The in the truss l force in th
ate Bridge (5ridges, in a
e with a funre was subjeigure 3(a), wGA) of 0.6g8g, recordedation for on
on, and s[5]
onent of (a) 1earthquakes
to the stronarthquake (
midspan, whment generdisplacemean MPGA ts than whatime-historchord at m
he chords as5] and otheaddition to
(b)
ndamental pected to twowhich was g, and the od at a site rene of the ho
994 .[5]
ng but shorChi-Chi-00hen subjecterated by thent due to of 0.08g, ca
at the much ry plot on tmidspan. Ths the much
er long-spantraditional
Transve
S‐Deflec
T2 = 9.5 s
period of o ground a strong
other the elatively orizontal
rt period 02). The ed to the he much Chi-Chi an cause stronger the right he much stronger
n bridges seismic
erse
tion
sec.
design pshould a
The
Loma Pand condue to Lsegmensome da
In thand Tracommisretrofit Associathe brid
The typical suspensthe timbucklingbridges their appof widthwhich myield cais neede
2.3 Test
To inthe authfull-scal
procedures,also be cons
FiguGo
Golden GatPrieta earthqntinued its sLoma Priet
nts of the bramage to thhe aftermathansportationssioned seisstudies und
ates [6], it wdge.
critical elemcolumn leg
sion spans. Te of designg of steel pbuilt prior plied comprh-to-thicknemeans the eapacity and ed to ensure
ts of Critic
nvestigate thor, as the Ple and ½-sc
Span Length = 1280
, the responsidered.
ure 4: (a) Theolden Gate B
te Bridge isquake. Duriervice afterta earthquakridge deck e expansionh of the 198n District, smic evaluadertaken bywas necessar
ments weregs of the apThe main ren and consplates was rto 1960’s, ression loadess, b/t rati
elements arecannot reac
e desirable c
cal Member
the post-bucPrincipal Invcale compon
(a)
0 m (4200 ft)
Abo
nse of these
e displacemeBridge to Nor
s located abing this earr the initial ike indicatedimpacting e
n joints, wh89 Loma Pwhich is a
ation and rey a joint venry to establ
e identified pproach strueason for thstruction ofrelatively lisuch as the d but have lio, in most e expected tch their yielcyclic behav
rs of the Go
ckling ductivestigator, lnents of the
lhassan Astaneh
5
e long-perio
ent response, rthridge and
bout 80 kilorthquake, thinspection. d that the deach other ich easily w
Prieta earthqa non-goveetrofit studinture of T.Yish the post
to be the cucture towere need for a
f the Goldeimited. Man
Golden Galimited postof these olto locally bd capacity avior during
olden Gate
ility of critiled a 2-yearmain truss
h-Asl
od structure
and (b) the fChi-Chi grou
ometers northe bridge su
The authordamage wain the long
was repairedquake, the Gernmental aes of the bY. Lin Intert-buckling b
chords of thrs and the lactual testinen Gate Brny elementsate Bridge, t-buckling cld bridges s
buckle priorafter bucklina strong ear
Bridge
ical elemenr test prograand the tow
s to long d
force responund motions
th of the epustained no r’s investiga
as in the forgitudinal dird. Golden Gatagency andbridge. As rnational anbehavior of
he two mainlegs of the
ng of these eidge, our ks of the croare sufficie
compressivesatisfies onr to reachingng. The posrthquake.
nts of the Gam to fabricwers of the G
(b)
istance eart
se of the [5]
picenter of tsignificant
ation of therm of two rection and
te Bridge, Hd owns the
part of thend Roy Imbcritical elem
n stiffeningmain tower
elements waknowledge oss sectionsently strong e ductility. Tnly the elastg their comst-buckling
Golden Gatecate realisticGolden Gate
thquakes
the 1989 damage
damage separate causing
Highway e bridge, seismic
bsen and ments of
g trusses, rs of the as that at of local of steel to carry
The limit tic limit,
mpressive ductility
e Bridge, c riveted e Bridge
and testthese tw
2.3.a T
The truss frowith piMemorawas insspecimeuniversaCivil anrate was
Durincertain were loafter bufailed abplate, Fcapacity
The b
bucklingway to was follthe long
t them undewo test prog
Test of Chor
stiffening tom joint to inned end andum No. stalled, caliens were loal testing mnd Environms relatively ng the mainload levels aded until b
uckling to obruptly at 8igure 4, at ay suddenly d
Figu
behavior ofg occurs in retrofit the lowed was
gitudinal dir
er monotonrams is prov
rd Member
truss chord joint as shcondition 4 of the S
brated and oaded by a
machine locamental Engislow; theren loading, tto record tbuckling ocbserve the
8,675 KN (1a location odropped to
ure 5: Truss
f specimen an elastic truss membto add hyd
rection to pr
Abo
nic compresvided. The
rs of the M
specimen whown in Figand accord
Structural Sttested for Southwark
ated in the Sineering of tfore, the testhere were he elastic uccurred andpost-buckli
1,950 kips).of about a quabout 50%
chord specim
indicated thmanner, thebers to incr
draulic damprevent the d
lhassan Astaneh
6
ssion load. full reports
Main Trusse
was a 7/8-scgure 5. Theding to thetability Resproper ope
k-Emery 17Structural Rthe Universsts can be rea number o
unloading bd load dropping behavio. This failuuarter of the(4,450 KN)
men and its l
hat it does ne load suddrease their dpers betwee
developmen
h-Asl
In the follos of the stud
es of the Go
cale model e latticed me proceduresearch Couneration, the,800 KN (4
Research Lasity of Califegarded as aof intentionaehavior of ped. The s
or and ductiure initiated e length fro) of the initi
local bucklin
not have anydenly drops.ductility, then the main
nt of large ax
owing sectidies are in [7
olden Gate
of a segmemember spees outlinedncil. After e axial load4,000,000 lbaboratory offornia at Bea static loadal unloadinthe specimespecimens wlity. The truby local bu
om the top. ial buckling
ng during the
y ductility a. Since therhe seismic rn trusses anxial forces i
ions, a sum7,8].
Bridge
ent of the secimens werd in the Tall, instrum
d was applib.) hydraulf the Departrkeley. The
d test. ngs and reloens. The spwere loadeduss chord spuckling of th
After buckg load.
e test [7]
and as soonre was no ecretrofit stratnd the towerin the truss
mmary of
ide span re tested
Technical mentation
ied. The lic-based tment of
e loading
oading at pecimens d further pecimen he cover
kling, the
n as local conomic tegy that r legs in chords.
2.3.b HCurre
history place totest prog
2.3.c T
The earthquaside of necessabucklingconsistewide flaspecimerivets tospecimeratio of actual m
Local Buckl
Historical Prently, Goldof design a
o exhibit a pgram. Figur
Figure 6
Test of the C
seismic retrakes, the tothe tower
ary to test thg strength ed of a 22 ange at midens, which o form a cen had widethe plates.
material in th
ing
reservationden Gate Band construpiece of the re 6 shows t
6: The Goldeat the
Component
rofit studiesower legs caleg will behe behaviorand post-bmm (7/8”) d-width to sconsisted o
cross. One e flanges ad Material fohe bridge w
Figure 7: No
Abo
n of Goldenridge on it
uction as wlattice mem
the exhibit a
en Gate Bridg Golden Gat
ts of the Ma
s conductedan actually
e under veryr of the pla
buckling duthick plate
stiffen it. Tof four cell specimen rdded to it aor the comp
which was S
on-ductile buof the G
ExistCond
lhassan Astaneh
7
n Gate Bridts south enell as seismmbers we tearea, where
ge specimente Bridge per
ain Tower
d by T. Y. Luplift up toy large comates at the uctility. Thee and a simThere were
wall platerepresented as vertical sponents of thilico steel w
uckling of fuGolden Gate
ting ition
NB
h-Asl
dge Latticedd has an e
mic retrofit.ested with a our test spe
n tested by Asrmeant exhib
of the Gold
Lin Int. [6] o 5 cm ( 2 impression abase of thee full-scale
milar plate ralso two 1/s connectedthe existin
stiffeners tohe specimen
with a yield
ull-scale towee Bridge
No Local uckling
d Test Specexhibition a The perm
a poster boaecimen is ex
staneh-Asl ebit site.
den Gate B
showed thainches) on and can loce towers ane main towetrofitted b/2-scale mad to each ong condition reduce thens was selestrength of
er specimens
cimen area that shanent exhib
ard that expxhibited.
t. Al. [7]
Bridge
at during thone side. T
cally bucklend to establwer base spby adding aain tower crother by angn while thee width-to-thcted to simu
f 345MPa (5
s
AR
hows the bit has a lains the
he strong The other e. It was ish their
pecimens a vertical ruciform gles and e second hickness ulate the 50ksi.)
After etrofit
Figurof the mcell walwaves cdirectiorepresenshowedfor the tsignifica
Figur
1/2-scalfull-scalthe exiswithout higher s
re 7 shows monotonic clls, Figure 7consisted ofn. The amnting the re
d very smalltwo specimant ductility
re 9 shows le cruciformle specimensting conditt much ductstrength and
S
the two fulcompression7 (left), failef about 2.5
mount of yetrofitted co if any buckens with rety.
Figure 8: A
existing andm specimensns summarition buckledtility. But, d yield cons
Figure 9: Nductile
70
60
50
40
30
20
10
0
Stress, (ksi)
80
0
Abo
ll-scale specn tests. Theed with limwaves in t
yielding apondition, Figkling deformtrofitted spe
Axial stress-s
d retrofitteds representinized above.d abruptly ithe retrofit
siderably be
Non-ductile be yielding of
0.0025 0.0
Crucifor½‐scale Specime
lhassan Astaneh
8
cimens of the specimen
mited yield lihe vertical
ppeared to gure 7 (righmations. Figecimen show
strain curves
d cruciform ng four cell Again, thin an elastictted specim
efore minor
buckling of ef the retrofitte
Existin
Strain
0050 0.0075
rm
en
h-Asl
he base of trepresentinines visible direction abe limited
ht) yielded gure 8 showwing no dro
s for the two
specimens l walls was he specimenc manner dr
men, Figure local buckl
existing plateed specimen
After Retrof
g Condition
0.01 0.012
Retrofit I‐shapes added.
the tower leg the existion the spec
and one wavd. In contrsignificantl
ws the axial op in compr
full-scale tes
after the tesvery simila
n, Figure 8 ropping the8 (right), wings occurr
es (left), and (right)
fit
S(
500
400
300
200
100
25 0.0150
0
egs after coming conditiocimen. The ve in the horast, the sply and afterstress-strain
ressive capa
sts
sts. The behar to the beh
(left), repre compressiwas able to ed.
Stress, (MPa)
mpletion on of the
buckled orizontal pecimen r the test n curves
acity and
havior of havior of resenting ive force develop
4 THE
The carries tthe AlbcoordincompletBridge and therespecti
The d
two laysupportetwo timparallel towers.
The supporteusing gapreservetimber, componof the bload carand prop
As fInterim the mainthe two This typ1989 Lretrofit
Figurindicate
TimbeTower
E ALBION
Albion Rivthe two-lan
bion River, nates of the ted and opewith the ma
e width of ively.
F
deck of the yers of planed on two l
mber trusses39.6 m (13 north and
ed on ten-lalvanized bed, aesthetisteel, and c
nents of the bridge indicrrying capacper selectiofor seismic Seismic Ren steel trussteel trusse
pe of seismioma Prieta of timber trre 12 shows
ed that there
TimbTrus
er rs
RIVER BR
ver Bridge ne scenic Ca
which flowbridge are
ened to traffain structurthe roadw
Figure 10: A
bridge, whnks supportelongitudinals in the nor30ft) long ri
south appegged brac
bolts. The bically pleasconcrete elebridge are
ates that thcity that it h
on of matericondition,
etrofit to thses and add
es from dropic retrofit hEarthquak
russes or tows a SAP Moe is a need
ber ses St
Tr
Abo
RIDGE
is located alifornia Hi
ws into the 39° 13' 34
fic in 1944. ral parts of
way (curb-to
A view of the
hich has a laed on longl steel trussrth and souiveted steel
proach spaned timber t
bridge is an sing timber ements of thin very gooe bridge, af
had when it al as well ain 2016, t
he bridge, wding “Cablepping off th
has been donke to prevenwers of the odel of the Ato conduct
RTteel
russes
lhassan Astaneh
9
in northernighway-1, oPacific Oc
4" N, 123° Figure 10 the bridge
o-curb) are
e Albion Rive
ayer of asphitudinal times comprisi
uth approactrusses sup
ns consist towers. Theexcellent hbridge. Fig
he Albion Rod conditionfter more thwas built. T
s good mainthe Californ
which consie-Restrainerheir supportne for othernt the collaAlbion RivAlbion Rivea thorough
R/C Towers
h-Asl
n Californiaofficially cacean after p46' 09" W,shows a geidentified. 295.4 m
er Bridge
halt overlay mber joists. ing the mai
ch spans. Tported on f
of 11.6 m e wood trushistorically gures 11 shRiver Bridgn. The mo
han 72 yearThis is a tesntenance. nia Departmsted of exters“ to the bet in the evenr steel truss apse of the er Bridge. er Bridge. Sh investigati
TimbeTowe
a near the alled Shorelpassing und, respectiveneral view The total l
(969 ft) a
on it, is a tiThe wood
n span (ovehe main sp
four-legged
(38 ft.) ssses and towsignificant hows typic
ge. The phost recent “L
rs of servicestimony to t
ment of Trending the bearings of tnt of future bridges in spans. The
Seismic Anion of seism
TiTr
er ers
town of Aline Highwder the bridely. The briof the Albiolength of thand 7.9 m
imber deck d joists, in ter the river)pan consistsreinforced
pan timberwers are coexample ofal close-up
otos indicateLoad Ratinge, still has tthe excellen
ransportatiobearing supthis span tostrong earthCalifornia sere was no
nalysis of themic behavio
mber russes
Albion. It way, over dge. The dge was on River
he bridge (26 ft),
made of turn, are ) and the s of two concrete
r trusses onnected f a well-
ps of the e that all g” report the same nt design
n added pports of o prevent hquakes. since the
seismic
e Bridge or of this
historicafind ouseismic damage
4.1 HistThe
listed onthe Depapplies made aembodierepresensignifica
The Ain U.S.equipme
ally significt exact seisretrofit to
e to its histo
Figu
torical signbridge has n the U.S. N
partment of to the Albi significantes “the distnt the workant and distAlbion Rive was contrent such as
cant bridgesmic retrofi
o ensure thrical appear
Figure 11
ure 12: Analy
nificance oftwo very imNational ReInterior. Thon River Bt contributitinctive chark of a mastinguishableer Bridge wrolled by ts tanks and
Abo
, at the levfit needs ofat the bridrance.
1: Close-up VR/C Parts of
ysis model of
f the Albionmportant hiegister of Hhe two criterridge are: (ion to the bracteristics ster, or thae entity who
was constructhe War D
d ships. Wh
lhassan Astaneh
10
el of what f the bridgedge survive
Views of Typf the Albion
f the Albion
n River Briistorical sig
Historic Placria in the Na(a) The strubroad patteof a type, p
at possess hose componcted during
Department hen the Wa
h-Asl
was done fe and to dees future ea
pical TimberRiver Bridge
River Bridg
idge gnificance thces by the Uational Regcture is “as
erns of our period, or mhigh artistients may laWorld Warand was u
ar Departme
for the Goldevelop proparthquakes
, Steel and e
e
hat have maU.S. Nationgister of Hisssociated wi
history; anmethod of cic values, oack individur II. At the tused mostlyent was ask
den Gate Bper and eco
without no
ade it eligibnal Parks Sestoric Placesith events thnd (b) the sconstructionor that repral distinctio
time, the stey to constrked by the
Bridge to onomical oticeable
ble to be ervice of s [2] that hat have structure
n, or that resent a on [2]. eel usage ruct war State of
Abolhassan Astaneh-Asl
11
California to supply steel for the bridge, the only items they received was two steel trusses, recovered from an old railroad bridge and some railroad rails and a limited amount of rebars. The steel trusses were used in the main span over the river. The rails were used as longitudinal rebars in the columns and rebars were used in various concrete elements. This connection of the Albion River Bridge to World War II has made the bridge significant as far as the U.S. history is concerned and satisfies the Criterion (a) mentioned in the previous page. The bridge also satisfies the Criterion (b) of the National Register of Historic Places as given in the previous page since it is one of the last remaining “well-engineered” timber bridges in California, and probably in the U.S. and represents a type, period, or method of construction that is no longer used.
4.2 Historical Registration of the Albion River Bridge
In 2015, a National Register Form was filed by John Johansen, a local architect, to register the Albion River Bridge as a United States National Historic Place. After more than one and a half year review of the application, the California Office of Historic Preservation [3] placed the case of the Albion River Bridge historical registration on the May 10, 2017 meeting agenda of the State Historical Resources Commission and asked for public comments. The author prepared a 14-page letter in support of the application and submitted it to the Commission, attended the meeting of the Commission and made in-person public comments in support of the application. At the meeting, the Commission unanimously approved the Albion River Bridge to be listed in the U.S. Register of National Historic Places and forwarded its recommendations to the Department of the Interior for final approval. 4.3 Challenges faced in historical registration of the Albion River Bridge
The efforts to register the Albion River Bridge as a National Historic Place has been quite challenging, though at the end, very rewarding when the bridge was registered. The main challenge and difficulty was that the California Department of Transportation (Caltrans),the state agency that owns, maintains, and operates the Albion River Bridge, not only was not supporting the historical registration efforts but appeared to be determined to push for demolition and replacement of this perfectly fine historic bridge in a very good condition and replace it with a reinforced concrete bridge. Caltrans was giving numerous reasons for replacement in its reports, such as, “the timber deck is rotten and crushing”, “the bolts are corroding”, “the steel truss has corrosion”, “the treatment material of the timber is releasing arsenic to the environment”, “the tsunamis can collapse the bridge”, “the cost of maintenance justifies spending more than $50 million to replace the bridge “, and several other reasons. The author using the results of his 3 years of investigation of the condition of this bridge, in his letter to the Historical Preservation Commission showed that none of the above-mentioned reasons are true and the bridge is in very good condition.
The main reason for demolition was given by Caltrans was that the timber deck of the Albion River Bridge “was rotten and crushing”. Under pressure from the Albion Community members and the author, in 2015 Caltrans materials laboratory did conduct actual in-situ tests and laboratory tests of the deck core samples and concluded that the deck, in fact, is in very good condition and is not rotting nor crushing. The corrosion of steel elements also proved to be not true and not a justifiable reason to demolish a perfectly fine historical bridge. The corrosion of galvanized bolts can be managed by proper maintenance of the bridge and by replacing the corroded bolts with better galvanized modern bolts that resist corrosion better.
Abolhassan Astaneh-Asl
12
5 CONCLUSION
1. The tests reported in this paper formed the basis of the seismic retrofit of the critical elements of the Golden Gate Bridge, which were the main stiffening truss and the base of the main towers. In both cases, the problem was that the truss chords and the base of the tower had relatively high width-to-thickness ratios, resulting in a very brittle local buckling of these elements under compression.
2. The local buckling problem of the main truss chords of the Golden Gate Bridge could not be retrofitted with the economy. Therefore, by using hydraulic dampers between the main trusses and the tower legs, the seismic forces expected during the future strong earthquakes were reduced and the local buckling of the truss chords prevented.
3. The tower legs of the Golden Gate Bridge do not have anchor rods to connect them to the foundations. As a result, during a major earthquake, the tower legs of the bridge are expected to uplift and compress down on the caisson foundations. Under the compression, the plates at the base of the tower legs can buckle locally prior to ductile yielding. The towers were retrofitted to prevent the local buckling by bolting vertical wide flange stiffeners to the mid-width of the plates. The tests summarized in this paper showed that the retrofit measure was able to prevent local buckling and enable the plates to reach their capacity in compressive yielding and have sufficient ductility.
4. Registering the Albion River Bridge as a U.S. National Historic Place was very challenging although eventually successful. The State Department of Transportation, the owner of the bridge, was not supporting the historical registration. The State Department of Transportation was and still is pushing for the demolition of this perfectly fine historically significant bridge and wants to replace it. This case showed that through the efforts of the Community and fact-based data supplied by the author, it was possible to stop the transportation agency from the demolition of a valuable historical bridge.
6 REFERENCES
[1] NRHP, “National Register of Historic Places”, website, National Park Service, Department of the Interior, Washington D.C., 2017.
[2] ACT, “National Historic Preservation Act of 1966 as amended through 1992, website, Public Law 102-575,16 U.S.C. 470, Passed by Congress, 1966.
[3] COHP, “California Office of Historic Preservation”, website, State of California, 2017.
[4] McCallen, D. Astaneh-Asl, A., and Larsen, S., “Seismic Studies of the San Francisco-Oakland Bay Bridge”, Proceedings of the 12th World Conference on Earthquake Engineering, Auckland New Zealand, (Paper # 2792), 8pp, 2000.
[5] Astaneh-Asl, A., “Seismic behavior and earthquake design of long-period structures”, Proceedings of the 5th International Conference on Structural Engineering, Mechanics and Computation, Cape Town, South Africa, (5-7/16), 81-424, 2012.
[6] Ingham, T.J., Rodriguez, S., Nader, M., and Taucer, F. “Seismic retrofit of the Golden Gate Bridge”, Proceedings of the 11th World Conference on Earthquake Engineering, Acapulco, Mexico, (Paper # 1396), 8pp, 1996.
[7] Cho, S-W., Astaneh-Asl, A., and Blondet, M., “Post-buckling ductility of critical members of the Golden Gate Bridge”, Report No. UCB/CEE-Steel-93/01, Dept. of Civil and Environmental Engineering, University of California, Berkeley, 1993.
[8] Bowen, C.M., and Astaneh-Asl, A., “Buckling Behavior of the Tower Legs of the Golden Gate Bridge”, Report No. UCB/CEE-Steel-96/07, Dept. of Civil and Environmental Engineering, University of California, Berkeley, 1996.