Seismic Evaluation of the US41 Northbound Bridge Over the Ohio Ri

8/18/2019 Seismic Evaluation of the US41 Northbound Bridge Over the Ohio Ri

1/152

Rsarch RrC-16

IMI vUION o H 41 oRHBOUND

RIDG OR H HIO IR NDRON,SR 96-173

by

Issam Harikrfer f Civil Engneering and ead Struture Sectin

Kentcky Tranprtatin Center

Chellia MadasamViiting Prfer Kentcky Tranprtatin Cener

Dengln Ceneear Aitant Dept. f Ci Engineering

K. VasudevanViiting Prfer Kentuky Tranptatin Center

Leonong ZouFrmerly Viitng Prfer Kentky Tranprtatn Center

Kevin SuttererAitnt Prfer Department f Cl Engineering

Ron SreeAitant rfer, Department f elgical Science

and

Davd L AllenTranprtatn Engineer Kentuky Tranprtatin Center

Kenty ranprtatn enteree f nneerin, nierity Kentuky

in cperatin it

ranprtatn anetmmnweath f Kenty

and

edera Hway dmintratnS Department f Tanprtatn

KY

e coe o epo eec e ew o e ao wo ae epoe o e ac ad accacy o e daapeeed ee e coe do o eceay eec e oca ew o poce o e ey o ecky eecky apoao Cae o e Fedea way Adao epo doe o coe a adadpeccao o eao e co o aace ae o ade ae ae o decao ppoe ad ae oo e codeed a edoee

Novemer 999


2/152

jms C C

eetary of raporato Jere MsDety ereary

M ose M. SpvdaDivisio Admiisato

Coonwlth of Ktucky

p CbFkfo

Kntucky 40622

Dcmbe 0, 000

da Higa Admiistatio330 Wst Boadaaot, Y 001

oveor

Sbjct: Impmtatio Statemet o ia Repo titd "Sismic Evaatioo t US1 Nobod bidg ov t Oio Riv at Hedso, YStd mb: YSPR 9-173Std tit Sismic Ratig ad Evaatio o Higa Stcts

Da . Spveda

T objctiv o tis std as to sismica evaate te US1 Notbod bdg ovt Oio Riv at Hdso, Y o a pojected 50a aqa vet T objectiv stot as b acivd b codctig edtstig, compt modig ad damic aasis.

sts o tis std so tat t spstct o t mai bidge i itstadt 50a etqae vt itot a damage A sppos o te pies o t mai bidgead ti ot o otto sppos avig xd baigs o bot te appoac spas qieot Tis tot ca b povidd b additioa aco bots i od to pvt sa aio te xistig aco bots, o b epacig ose baigs it seismic isoatio baigs

MY/L/dp

c o

KENTUCKY TRANSPORTATION CABNT

Sicee,

Stat Higa Egiee

qPROVD A SAF, FFCENT EVRONMENALL SOUN, AN FSCALLY RESPONSBLE TRANSPORTATON SYSTE

WHCH PROMOTES CONOC GROWTH AND ENANCS TH

QUATY O L N KNTUC:'

"AN E

QUAL OPPORTUN EMPOR M

/

/D


3/152

cc Reot Dc Pge1. Report No . Government Accession o. Reipient's Catalog No.

TC-16

4 Title and Subtitle Report DateSEIMIC VALUATION OF THE S41 Novbr 1

ORTHBOUND RIDGE OVER THE 6 Performing Organization Code

HIO IVER AT ENDERON, KYYR 96-173 Performing Organization Report Author(s) I. ari CM Maasay, D. hen K Vadva o

Zh, K. Serr R Sr an A TC--16 erforming Organization Name and Address 1. Work Unit o RAIS

nucy Transoraon CnrCog of Engnrng 11 Contrat Grant Nonvrsy of nucy SPR 6-13

Lxngon nucy 40506021 1 Type of Report and eriod Covere

1. Sponsoring Ageny Name and Address Fnanucy ransoraon CabnSa ffc Bung 14. Sponsoring Ageny Coderanfor, nucy 40622

1. Supplementary NotesPrar n cooraon wh h nucy Transoraon Cabn a h SDarn of Transoraon, Fra Hghway nsraon

16 AbstractThi rprt prt th mi vaat th US41 Nrthd ridg vr th Ohi Rvr t

Evavi daa ad Hdr Ktky h mai ridg i a ·-pa ativr thrghtr typ Thapprah rdg ha 8 pa th Evavi N d ad 35 pa th dr d thgh th rdgha t yt jtd t a mdrat r mar artha it i tatd wth th th Nw Madrd aWaah Vay Sim Z

h m vaat prgram td d ttig ad imi rp aay h mda prprti th ma rdg wr dtrmid thrgh fd ttig ad wr d t airat a thr dma ft mmd h t mt md wa th td t tim htri f th 50yar arthak vt Str adpamt tad wr d t wth th apta imt aytia rt dat that th prtrtrfth ma rdg wi vv th ptd yar arthak witht ay damag ad fpa wvr apprt th pr th mai rdg rr addtia ahr t r m iat arg

h apprah pa wr aayzd g rp ptrm mthd wth impid gdgrfrdmmd Thirt t rtytw pprt havg d arig th th Ktky ad daa apprah parr addta ahr t at th fd arg r m iat arig

7. Wd Distribution StatementSsc vauaon, -Hsory S41 n wh arova ofNorhboun Brg sng Fn nucy ransoraon Cabn

n o Rsons Scra

1 Seurity Classif. (of this report Security Classif. (of this page of ages ricencassf ncassf 15

FormDOT 1700.7 (8-72}Repoducn of Coleted Page Auhoze

11


4/152

xI uMR

Research Objectives

The an obecve of hs nvesgaon s o assess he srucura negry ofhe ho Rver brdge (Fgures E- , E-3 and 5 on S41 Norhbound a Hendersonenucy, when subeced o a proeced 50-year earhquae. The nvesgaonconsders boh he an brdge and he approach spans To acheve he obecve, hescope of he wor was dvded no he foowng ass Fed esng of he anbrdge 2 Fne eeen odeng and cabraon 3Te-hsory sesc responseanayss; and 4 Sesc response ofhe approach brdges usng he response specruehod.

Background

The need for evauang he sesc adequacy of he esng nfrasrucure hascoe no focus foowng he daage and coapse of nuerous brdge srucures dueo he recen earhquaes. For eape he 1 Loa Prea earhquae and 14Norhrdge earhquae brough he sesc rs o brdges and eevaed freewaysrcures o he aenon of he pubc In parcuar, he sesc rehabaon ofoder brdges n regons of hgh sescy, whch were desgned pror o he advenof odern sesc desgn codes s a aer ofgrowng concern The S41 Norhboundbrdge a Henderson enucy was bu n accordng o earer codes ha had

na provsons for earhquae oadng

Fiel estng

The aben vbraon properes of he an brdge were deerned hroughfed esng under raffc- and wnd -nduced ecaon he purpose of easurng heaben vbraon properes was o deerne he naura frequences and herassocaed ode shapes These vbraon properes were subsequeny used as hebass for cabrang he fne eeen ode for sesc response anayss

Finite Element oeling

hree densona fne eeen ode of he an brdge was used for freevbraon and sesc response anayses. The ode was cabraed by coparng hefree vbraon anayss resus wh he aben vbraon properes obaned fro

lll


5/152

ied esing Ae caibaion he mode was used o seismic esponse anasis Thehee dimensiona mode o he main bidge was subeced o he ime soies o hepojeced 50ea eahquae o deemine maimum dispacemens ajoins, sessesin membes, and oces on beaings

Appoach pans

The apoach spans wee modeed using simpiied snge-degee-oeedomssems The seismic esponse was anazed in he ongiudina diecion usingesponse specum mehod Fo he appoach spans, he seismic anasis dea wihhe poenia o oss-o-span due o ecessie ongiudina dispacemens and beaingoces aong he highwa main ine.

Recommendations

The seismic anasis indicaes ha he main bidge can esis he 50eaeahquae een wihou ieding o bucing o uss membes and osso-span asuppos The anasis indicaes a possibii o ancho bo shea aiue a a piebeaings. n ode o aoid ancho bo shea aiue a a pie beaings addiionaancho bos ae equied o epacemen o he eising beaings wih seismicisoaion beaings is suggesed (Figue E4 Chape 5 pesens he deais o hepoposed eoi measues o he main bidge (Figues 5 hough 53 and Tabe56.

The appoach spans on he Hendeson, K side hae he poenia o anchobo shea aiue due o ongiudina seismic oce a ie ou o hiou supposhaing ied beaings Theeoe eoiing o he ied beaings a hose supposwih addiiona ancho bos o epacing he eising ied beaings wih seismicisoaion beaings is ecommended (Figue E5 Fo a he epansion beaings hebeaing dispacemen Capaci/Demand aio, is geae han 0 and hence ossospan canno occu

Simia he appoach spans on he Eansie IN side hae he poenia oancho bo shea aiue due o ongiudina seismic oce a a eigh suppos haingied beaings. Theeoe eoiing o he ied beaings a hose eigh suppos on

he appoach spans wih addiiona ancho bos o epacing he eising iedbeaings wih seismic isoaion beaings is ecommended (Figue E-6 Fo a heepansion be aings he beaing dispacemen Capaci/Demand aio, is geae han0 and hence oss-ospan canno occu Chape 6 pesens he deais o hepoposed eoi measues (Figues 6. 7 hough 6 .6 and Tabes 6 .4 hough 6 ohe boh appoach spans.

lV


6/152

Fgue E. 4 Bdge ove he Oho Rve a Hendeon KY

v


7/152

Fgu E-2 A Vw of Hdso, KYAppoach Bdg o h US4

Nohbod Bdg

V


8/152

Fgure E-3 he US 4 Northbound pproach Brdge at Eanse N(Northbound on ef sde n the pcture)

Vll


9/152

�·

CANLEVER NER'

"

� em• _,

360' 180l

6 36 4

EXP,

P. FXP

XD

PI!R A R I E D

- 5' 6�0

HSON, KY· ·· ER I

·

\fiR ;� 3 RADAY cTUE /� ·

ER ·vq

280kips vreg

t35s

5sVq vq

65

r�

0s

Figu E4 inimum Rquid Sha Capacty to b ovidd by Addtional Ancho bots at Baings fo th S 4 Nothbound an Bidg

t Ree Fe 5 thh 51 the pe ett etls Altet tt l t e th t th ei lt


10/152

>

V x 0 psT H Vr X 80 kp·T

,v. l

i

.

f

'

E

F

l

E

l

"

E F

r

r ;

\ · E!

V q X 00 00 kp

E

8 ps

E

' g •p• td7 /+ /� / S- \ } /

jmj,•ljsj

§ G @ G G EEANNOTES:

Elev. 5 Ee 5 F denotes Fixed BeargE deoes Epason eag Hnn, Y

ugh

PAN

Fig E-5 inimm Rid Sha Capacity , to b ovidd by Additiona Ancho Botsat Fixd Baings on th Hndson Appoach of th S4 Nothbond Bidg

Nte Ree Fres h 1 r he se rer eas Aterae rer wd e eace he exis xed eans wth sesc sain eas

1


11/152

Vq X Vq X X 8 V X X 8\

� 560 kl . - � 280 kps 260 kips 8 k

0 e4°65

· �Grade2.759 · · �\

1

IZ\

IZW

>

1'

I

?f"

Z

1

7

P

jh i

E

V

S

:

f

•

v. '

E

! · .

•

391.1

-152 -B

�51 ·1L1'151 1

-

11

�

l01 7.

1

01

1 7-

t

ELEVANS eoe e e eoe o e

v ,.

n= =

==

�

==

==

t

==

=

=

�

==H

(

\

\

\

� B AN


12/152

KNOWDGMN

Th fnanca suort for ths roct was rovdd by th KntucyTransortaton abnt and Fdra Hghway Admnstraton Th h of JohnFnstn and ar ravs n coordnatng and conductng th brdg tstng sscay notworthy Th authors woud to acnowdg th cooratonsuggstons and advc of th mmbrs ofth study advsory commtt onad Hrd(commtt charrson nn van Ray rr avd Moss Td No NB. Shahand avd St.

Th authors woud aso to acnowdg th arta suort for qumntby th Natona Scnc Foundaton undr grant MS-90 4ARI rogram

Xl


13/152

TABLE OF CoNENSECRPON AGE

Immntaton ttr . . . . . . . . . . . . . . . . . . . . . . . . .

Thna Rort oumntaton ag . . . . . . . . . . . . . . . . . . . . . . .

EEUTIVE SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . .

AKNOWEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

TABLE OF ONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .x

IST OF TABES xvIST OF FIURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

1 INTROUTION . . . . . . . . . . . . . . . . . . . . 1

1 1 nra . . . . . . . . . . 11 2 Fd Tstng 2 .3 Earthqua Baground . 214 So ofth wor 3

2 THE US41 NORTHBOUN BRIE OVER THE OHIO RIVER ATHENERSON KENTUKY

5

2 .1 nra 52.2 Brdg Surstrutur 52 3 Fxd and Exanson Barngs 2.4 Brdg Substrutur . .

3. FIE TESTIN 3. 1 nra 32 nstrumntaton

3.3 Tstng rodur 9

34 ataAnayss 93 5 Fnt Emnt Mod abraton . . 1 1

Xll


14/152

4 FINIT LMNT MODLIN AND FR VIBRATION ANASIS 54 nra 54.2 Fnt mnt Mod. 543 Fr Vbraton Anayss . . 1

5 SISMI RSONS ANALSIS205 nra.2052 Ssm Rsons 2 5 3 aaty/Dmand Ratos 255.4 Rtroft for t Man Brdg . . . . . . . . . . . . . . . . . 2

. AROAH BRID 21 nra 2 2 Strutura Modng

2

3 Ssm Rsons Anayss 284 aaty/Dmand Ratos 29 5 Rtrot for th Aroah Brdg 30

7 ONUSIONSAND ROMMNDATIONS 3 7 nra32 ManBrdg3.3 AroahBrdg32

RFRNS 33

lll


15/152

LIST OF TABLES

Tabl Dscption PagNo. No

3a US4 1 Nothound dg tstng dtas - Movng staton on 3ght an

3 US1 Nothound dg tstng dtas Bas staton on ght 3an

32a US41 Nothound dg tstng dtas Movng staton on ft 38an

32 US41 Nothound dg tstng dtas Bas staton on ft 39 an

3.3 Fquncy dntfcaton fom th fd tst data 404. 1 Natua fquncs and mass atcaton of th man dg 42

Exact gn systm)42 Natua fquncs and mass atcaton of th man dg 43Rtz vcto asd)

5 1 D scton of ssmc xctaton cass 44 5 2 oss sctona ots of mms fo stss cacuaton 4553 Stsss s) n mms du to ssmc xctaton cas 46

T2V3 dad oad and tmatu5.4 Stsss s) n mms du to ssmc xctaton cas 4

2TV3 dad oad and tmatu55 Stsss s) n mms du to ssmc xctaton cas 485 Stsss s) n mms du to ssmc xctaton cas 22 49

5 Stsss s) n mms du to ssmc xctaton cas TT 505.8 Stsss s) n mms du to ssmc xctaton cas TT22 515.9 Stsss s) n mms du to tmatu of 90F 52510 Sfwght nducd stsss s) 53 5 11 Stss qumnt asd on SHTO Equatons fo T2V3 54

athqua5 12 Stss qumnt asd on SHTO Equatons fo 2TV3 55

athqua5.13 Dsacmnts n) du to ssmc xctaton of th 50ya 5

athqua vnt514 Dsacmnts n) du to sfwght and tmatu 5515 Maxmum and mnmum as shas fom moda tm-hstoy 58

fo th 50ya athqua51 Bang foc caacty/dmand atos of th man dg wthout 59

st so coffcnts fo th 50-ya athquaa acuaton of sustuctu wghts fo 150 tuss sans 0 acuaton of sustuctu wghts fo 100' tuss sans 0

X

V


16/152

1234

5

66

6

auaton of supstutu wghts fo 4 gd spanauaton of p stffnss and p mass of SDOF systmsauaton of ssm sponsBang fo /D atos fo th fxd bangs on thEans IN appoah spans

Dspamnt /D atos fo xpanson b angs on thEans IN appoah spansBang fo /D atos fo th fxd bangs on thHndson appoah spansDspamnt /D atos fo xpanson bangs on thHndson appoah spans

XV

1234

5

7


17/152

LIST OF FIGURES

Fig Deciption PageNo No

21a US1 bdgs ov th Oho v at Hndson, KY Entanc 8V

21b Sd vs of th US1 bdgs ov th Oho v 821c End pota of th US1 bdgs 92d Typca hng ocaton on US1 bdgs 69 2 Insd v shong potas coss bacngs tc 702.2 Pan and vaton vs of th US 1 nothbound bdg ov 71

th Oho v2.3 Evaton v o f th fst span A-B 722 Evaton v of th scond span B 73

25Evaton v of th thd span -D 7

2 Evaton v of th fouth span DE 7527 Tansvs coss scton of th US51 man bdg 76 2.8a Pan v of p A and E 77 28b Evaton vs of p A and E 772.9a Pan v of p B and D 782.9b Evaton vs of p B and D 783a Taxa accomt boc 7931b Accomt postons on th bdg 79 31c Accomt pacmnt on th dc 8032a Tansvs accaton tmhstoy obtand fom fd tstng 81

at movng staton 32b FFT of tansvs accaton tmhstoy at movng staton 8132c Vtca accaton tmhstoy obtand fom fd tstng at 82

movng staton 3.2d FFT of vtca accaton tm-hstoy at movng staton 8232 ongtudna accaton tmhstoy obtand fom fd 83

tstng at movng staton 32f FFT of ongtudna accaton tm-hstoy 83

at movng staton 33a Fst tansvs mod 833b Pa compason fo th fst tansvs mod 8

3.a Fst vtca mod 853b Pa compason fo th fst vtca mod 8535a Fst ongtudna mod 83.5b Pa compason fo th fst ongtudna mod 83a Scond tansvs mod 873b Pa compason fo th scond tansvs mod 87

X


18/152

37a Sond rta mod 8837 a omparson for th sond rta mod 8838a Thrd transrs mod 8938 a omparson for th thrd transrs mod 8939a Thrd rta mod 90

39 a omparson for th thrd rta mod 90 1 3 fnt mnt mod ofth US1 Northound rdg 9 1

(a) somtr w () aton w and () pan w2 Mod shap of th frst natura frquny (053 Hz) 92

(a) somtr w and () pan w3 Mod shap of th sond natura frquny (07 Hz) 93

(a) somtr w and () pan w Mod shap of th thrd natura frquny (0 781 Hz) 94

(a) somtr w and () pan w5 Mod shap of th fourth natura frquny (0 82 1 Hz) 95

(a) somtr w () aton w and () pan w Mod shap of th ffth natura frquny (0 89 1 Hz) 9

(a) somtr w and () pan w4. 7 Mod shap of th sth natura frquny (1 022 Hz) 97

(a) somtr w and () pan w48 Mod shap of th snth natura frquny (105 Hz) 98

(a) somtr w () aton w and () pan w.9 Mod shap of th ghth natura frquny (1 12 Hz) 99

(a) somtr w () aton w and () pan w 10 Mod shap of th nnth natura frquny (1 17 Hz) 100

(a) somtr w and () pan w

1 1 Mod shap of th tnth natura frquny ( 375 Hz) 101(a) somtr w () aton w and () pan w12 Mod shap of th nth natura quny (1 5 Hz) 102

(a) somtr w () aton w and () pan w13 Mod shap of th twth natura frquny (1539 Hz) 103

(a) somtr w and () pan w1 Mod shap of th thrtnth natura frquny (1 37 Hz) 10

(a) somtr w () aton w and () pan w15 Mod shap o f th fourtnth natura frquny (1 Hz) 105

(a) somtr w () aton w and () pan w1 Mod shap of th fftnth natura frquny (1 751 Hz) 10

(a) somtr w () aton w and () pan w5 1 Tmhstory and rspons sptra dntfaton map for th 107

ommonwath of Kntuy52 Aratontm hstory o f th horzonta omponnt of th 50 108

yar arthqua

X


19/152

53 Accatontm hstoy of th tca comonnt of th 10850ya arthqua

5.4 Accaton-tm hstory of th tansrs comonnt o f th 50- 109yar arthqua

5.5 sacmnt-tm hstory n th transrs drcton at nod 109

und th 1T2V3 xctaton cas5 sacmnttm hstory n th rtca drcton at nod 110

und th 1T2V3 xctaton cas57 sacmnttm hstory n th ongtudna dcton at nod 110

und th 1T2V3 xctaton cas8 Axa forc-tm hstory of mm 1 undr 1T2V3 xctaton 1 1 1

cas5.9 Mnmum qurd sha caacty for A on th man dg 112510 Mnmum qud shar caacty fo r B o n th man dg 1135 1 1 Mnmum rqud sha caacty fo on th man rdg 11512 Mnmum qurd shar caacty for r on th man rdg 115513 Mnmum rqud shar caacty fo r E on th man dg 1 1

1a Tuss sans n Eans IN aoach rdg 117 1 rd sans n Eans IN aoach dg 117 1c V of Eans IN aoach dg 118 1d V of Hndson, K Y aoach rdg 118 2 an and aton s of Eans, IN aroach dg on 119

th US1 northound rdg 3 an and aton s of Hndson KY aroach dg on 120

th US1 southound rdg Sng dg of fdom systm mods for Eans IN 121

aroach 6.5 Sng dg of frdom systm mods fo Hndson KY 122

aoach Rsons scta fo th 50yar nt for Hndrson KY 123

(015g2 fom fg 51 amng rato 005 6.7 Aangmnt of addtona anchor ots on r N1 12 8 Arangmnt of addtona anchor ots on N3 125 9 Arangmnt of addtona ancho ots on r N5 12 10 Arrangmnt of addtona anchor ots on r N 127 1 1 Aangmnt of addtona anchor ots on N7 128 12 Arangmnt of addtona anchor ots on N8 129

13 Arrangmnt of addtona ancho ots on r S1 130 1 Arangmnt of addtona anchor ots on S3 131 15 Aangmnt of addtona ancho ots on r S 132 1 Aangmnt of addtona anchor ots on S5 133

Xll


20/152

TRDUCT

General

h t th ssmc c st stuctu hs cm tcus foong th damag and coas of numous stuctus dung cntathquas In atcua th ssmc habtaton of od bdgs hch dsgnd o to th advnt of modn ssmc dsgn cods s a matt of gongconcn n gons of hgh ssmcty Bdg faus fom athquas hav so faony occud n afona and Aasa Th 1989 oma Pta athqua EERI1990] and 1994 Nothdg athqua [EERI 1995] hav bought th ssmc s tobdgs and vatd fay stuctus to th attnton of th ubc Th atacoas of th San Fancsco Oaand Bay Bdg and th yss Vaduct oton

of Intstat 880 not ony causd th oss of f but catd consdab obms toth tansotaton nfastuctu Th Bay bdg as unusab fo a month andtansbay commuts focd to commut on fs o th codd Bay Aa RadTanst Systm Foong th oma Pta athqua th Fda HghayAdmnstaton commssond th ssmc vauaton of bdgs ocatd n ssmcayactv gons

Aft ssmc vauaton f th bdg s found to b dfcnt not a bdgsn hghay systm has to b tottd smutanousy nstad ony thos bdgsth th hghst oty shoud b tofttd fst It shoud aays b mmbdthat ssmc tofttng s on of sva ossb couss of acton Oth ossb

actons a cosng th bdg acng th bdg tang no acton at a andacctng th s of ssmc damag

Ssmc dsgn of bdgs thoughout th Untd Stats s govnd byAASHTOs Standad Scfcatons fo Hghay Bdgs Dvson IA (199 Us ofth AASHTO scfcatons s ntndd (1 to ao th stuctu to yd dung amajo athqua (2 to ao damag (ydng ony n aas that a accssb(vsb and aab and (3) to vnt coas vn dung vy agathquas (NHI 199 Th a many bdgs n th ommonath of Kntucyhch dsgnd bfo th ssmc ovsons ntoducd nto th AASHTOod Rcnty th BntSnc bdg on Intstat 7 connctng ovngtonKntcy to ncnnat Oho a doub-dc though-tuss bdg as vauatd fossmc xctaton Ha t a(199ab] Th a many ongsan though-tussbdgs n Kntucy hch qu ssmc vauaton Th snt o concntatson th ssmc vauaton of th US41 Nothbound Bdg ov th Oho Rv Thsbdg conncts US41 acoss th Oho Rv btn Hndson K and EvansvIN

1


21/152

2 Fiel Tesing

Nowadays fd tstng of bdgs has bom an ntga pat ofth ssmvauaton poss n od to mnat th untants and assumptonsnvovd n anayta modng. Fusa dynam tsts on stutus an b

pfomd n a numb of ways. Hudson (1977) dsbs th dffnt typs oftstng as (1) f vbaton tsts nudng () nta dspamnt as n thpubak qukas tst and () nta voty fom mpats (2) fodvbaton tsts nudng () stady-stat sonan tstng, () vaab fqunyxtaton nudng swp undown andom and pus squns, and ()tansnt xtatons nudng athquaks wnd ta and xposons. Shy(1995b) povds a vy nfomatv dsusson of th advantags anddsadvantags of th vaous tst mthods usd on hghway bdgs

An atnatv thnqu usd to dynamay tst bdgs masus th

bdgs spons und noma taf and wnd In ths mthod no qupmnts qud to xt th stutu, nstad qupmnt s qud ony to od thvbatons Ths thnqu has bn usd by a numb of sahs (Abdghaff and Sanan 1985ab Aampa and Fu 199 Bukand t a 1979, Do199 Faa t a. 1995 aut t a. 1995 Sad t a. 199, Shahawy 1995Vntua t a 19 9, Wndhansky t a 1995 ) Hak t. a usd ths mthodwth suss to dntfy th vbaton mod shaps and fquns of th BntSpn Bdg at Covngton K (Hak t a 1997ab) and S5 1 Bdg atWkff K (Hak t a 1998)

arqake Backgron

Th tst bdg s oatd n Hndson ounty Kntuky n th WabashVay Ssm Zon Th two agst athquaks known to hav oud n thson w n 1891 and 198 Stt t a. (199) auatd an m of 5 .5 to 5 8 foth Sptmb 27, 18 91 vnt Ths athquak was ntd na Mt. Vnon,Inos wh sva hmnys w shakn down and a huh was damagdTh Novmb 9 198 athquak was mo damagng than th 1891 on sn thaa was muh mo dns y sttd and mo vunab to damag. Stov andCoffman (1993) stmatd th m of th two vnts as 5 2 and 55 sptvy

Th most sgnfant nt athquak n th Wabash Vay Ssm Zonwas on Jun 10 1987. Tayo t a. (1989) stmatd th m of ths vnt at 5 2and dsbd t as a pdomnanty stksp vnt wth a foa dpth of 10 km.

2


22/152

Ntt and Hrrmann (1978 stmatd a maxmm crdb arthqa ofm for th Wabash Vay Ssmc Zon Mor rcnty Obrmr t a (1 992 fonddnc of on or mor strong arthqas cntrd nar Vncnns N Basd on thara xtnt of qfacton fatrs (ds Obrmr t a. (1992 concdd that fa th ds ar from a sng nt th of shang od ha bn on th ordr

of m a magntd that s n cos agrmnt th Ntt and Hrrmanns (198maxmm crdb arthqa

Wth ncrasng rcognton of otnta damag from a arg Wabash Vayarthqa or othr ss sr qa th Kntcy Transotaton abnt nddth rsarch roct Evaluation and Analysis of Innovative Concepts for BridgeSeismic Retrofit. Rsarch as condctd by th Kntcy Transortaton ntr atth nrsty of Kntcy Fndamnta to ths rsarch roct as thcharactrzaton of th ssmc otnta affctng Kntcy from non ssmc onsas as nnon oca nts Rsts from ths ssmoogca assssmnt ofKntcy r bshd n Source Zones, Recurrence Rates and Time Histories forEarthquakes Affecting Kentucky (Strt t a 199 In ths rort thr man tassr cord (1 dfnton and aaton of arthqas n ssmc ons that hath otnta to gnrat damagng grond motons n Kntcy (2 scfcaton ofth sorc charactrstcs accontng for th sradng and attnaton of th grondmotons to toof-bdroc at sts n Kntcy and (3) dtrmnaton of ssmc onngmas for th ommonath basd on a-artc accratons rsons sctraand tmhstors

Tmhstors gnratd n th aformntond rort r sd n th ssmcaaton of th US1 northbond brdg Effcts of ths artfca arthqas r

cacatd for bdroc aton at th conty sat of ach Kntcy conty Thsaccraton tmhstors r drd throgh th s ofrandom braton anayssand ta nto consdraton th robabty of arthqas om narby ssmc onsth attnaton of grond motons th dstanc n th ntra Untd Stats and thossbty of a random nt occrrng otsd of th gnray rcognd ssmcons (Strt t a. 199

4 Scope of e Work

Th rmary am ofths stdy s to assss th strctra ntgrty of th US41northbond brdg hn sbjctd to a 50-yar arthqa nt at Hndrson oKntcy To ach ths th sco of or as ddd nto for tass: 1 Fdtstng of th man brdg 2 fnt mnt modng 3) tm hstory ssmc rsonsanayss of th man brdg and ssmc rsons of th aroach brdg

3


23/152

he ambent vbaton popetes of the man bdge wee detemned thoughfed testng unde taff and wnd ndued extaton The pupose of measung theambent vbaton popetes s to detemne the mode shapes and the assoatednatua fequenes Fu sae ambent o foed vbaton tests have been usedextensvey n the past to detemne the dynam haatests of hghway bdges

Abdeghaffe and Sanan 1985ab).

A tee mensona fnte eement mode of the man bdge s used fo feevbaton and sesm esponse anayses. The mode s fst abated by ompangthe fee vbaton anayss esuts wth ambent vbaton popetes fom fed testng.Ate the abaton the mode s used fo sesm esponse anayss to detemne themaxmum dspaements stesses n tuss membes and foes on beangs.

he appoah spans ae modeed usng smpfed snge-degeeof-feedomSO systems. he supestutue mass s umped at the top of the pes Fo theappoah spans the sesm anayss deat ony wth the potenta fo ossof-span dueto ongtudna dspaement and foes on the beangs Sesm esponse s anayzedn the ongtudna deton ony usng the esponse spetum method to detemnethe maxmum dspaements and foes.


24/152

TH 41 oRHBOUND RIDG OR HHIO IR NDRON, NUKY: IN

RIDG

21 Genera

Th Oho Rvr brdg on US41 northbound, shown n fgurs 2 a)-) s acantvr throughtruss brdg, a brdg ty commony moyd for sans of 00'183 m) to 1500 457 m) through th md 1970 's. Ths brdg was orgnay dsgndby Mods and Mastrs Engnrs n 1929 . Fgurs 2 1 a)-) show th drntvws of th man brdg. Th tota ngth of th brdg ncudng aroach sans s5395 25" Th ngth of th foursan man brdg s 2293' 15 Th an and

vaton o th man brdg ar shown n Fgur 22 Th surstructur trussmmbrs ar mad o structura st wh th substructur rs ar mad ofrnforcd concrt Th dtas of aroach brdgs and thr ssmc vauaton ardscussd saraty n hatr .

22 Bridge pertrre

Th surstructur s dscrbd n trms of th vrtca truss systm, th atratruss systm and th oor systm. Th atra truss s a combnaton ofatra bracngsway and orta bracngs Th brdg s a throughtruss ty wth susndd sans,fxd sans, anchor arms and cantvr arms

As sn from Fgur 22 th hght of th vrtca truss nar ach mdsan s55 and at ach ntrna suort s 75'

Th vrtca truss systm, shown n Fgur 22, conssts of a smsusnddsan of 30' btwn rs A and B whch s suortd ovr r A and a cantvrarm B of 180 ' as shown n Fgur 23 B- s a fxd san Fgur 2 4), btwnrs B and sannng 00 In san Fgur 25) thr ar two cantvr armssannng 180' ach Furthrmor '' and '' suort a susndd san of 30 as

shown n Fgur 22 Th san btwn rs and E Fgur 2.) s rovdd wth ananchor arm -E' sannng 432 7 Th ngths o san AB B, and E ar 540' 5 00 , 72 0 and 432 7 rsctvy.

5


25/152

Th vta tuss mmbs w mad of mdum abon st o son stShop vts of 1 da w usd fo man tuss mmbs 7/8 da w usd fovtas oo bams stngs atas and sway bang Fd vts of 1 da wusd fo a tuss mmbs and oo bam onntons 7/8 a w usd fo stngonntons atas and sway bangs Expt fo a vy fw " B stons fo

vtas a oth mmbs w mad ofbut-up stons usng hanns angs andwb pats Many vta tuss mmbs n th tapd poton na th p suppota onntd by pns of 10" da

Th ata tuss systm onssts of ata bang mmbs n th top andbottom hod pans ombnd wth potas and sway bang btwn th two vtatusss as shown n Fgu 21 At th hng oatons ongtudna sdng jonts both th top and bottom hods a dsgnd fo f thma xpanson

Th oo systm onssts of a 7 th ont sab suppotd by ongtudnaWF stngs whh a ad by tansvs but-up oo bams as shown n Fgu2 Th wdth of th oadway s 30 . Th ongtudna stngs a spad at ' 9"Th oo bams span 36' btwn th vta tusss and a attahd to th tussvtas Th handas a attahd to th tuss mmbs on th of th d

23 Fxe an Expansion Bearings

Th supstutu s suppotd by xpanson o b angs on ps A Band E and fxd bangs on ps and D Th xpanson bangs on ps A andE pmt ongtudna tansaton and ongtudna otaton Th xpanson bang

on p B aows ony ongtudna tansaton Th fxd bangs do not aowongtudna otaton and tansaton

Th fxd bangs onsst of th ays of but-up stons botd togthTh bottom of th bang s onntd to th p though anho bots Th sz of thbang s 7' " n ngth and 5' wd Th a a tota of fou 2" da anho botsunnng nto th p ont Th anho bots a spad at 4 9 n ngthdton and 5 n wdth dton

Th xpanson bangs on p A and E onsst of pn and o ombnatonsto aow otaton and tansaton Th top sho of ths bang s onntd to thbottom hod of th vta tuss and th bottom sho s onntd to th p thoughanho bots Th a a tota of fou 2 da anho bots unnng nto th pont Th s of th bang s " n ngth and 4 wd

Th xpanson bangs on p B onsst of th ays of but-up stonsbotd togth Th top ay s botd to th bottom hod of th vta tuss and


26/152

the botto ayer s onneted to the per through anhor bots The dde ayeronssts o roers to aow ongtudna transaton. There are a tota o our daanhor bots runnng nto the onrete The se o the bearng s 6 n ength and6 wde

2. Brige Sbsrcre

The an brdge s supported on pers A D and E whh are o taperedwa type pers wth a batter o per t A the pers are supported on assonoundatons The heghts o the asson oundatons or pers A and E are 1015' and10 57. The heghts o per A and E above the asson oundatons are 6 1 and9' 7" The pan and sde eevatons o the per A and E are shown n gure .8a-b.The hange n the ross seton n these pers near the top s any to aoodatethe dek-tuss type approah spans. Pan and sde eevaton and pan vew o the pers

and D are shown n Fgures 9a-b. The heghts o the asson oundatons o per, C and D are 73', 71 .5 and 69 The heghts o per C and D above the asson are101 /8, 10 6(18 and 10 1 /8 A the pers are onstrted wth renoredonrete ass D The renoreent n the per onssts o 3/ da reba unnnghorontay and vertay at /. The enter to enter dstane between bearngss 36


27/152

FIELD TESING

31 General

Field testing o a bidge povides an accuate and eliable desciption o itsactual dynamic chaacteistics. Field testing was conducted on the US41 nothboundmain bidge Testing was conducted on ight and let lanes. Since thee is nosymmety in the longitudina diection o the bidge the ul bidge was tested Almeasuements wee taken by placing the instuments on the pavement due to the imited access to the actual oo beams and the time constaints involved Eachinstument was p aced with its longitudinal ais aigned p aale to the longitudinaldiection o the bidge. Ambient vibation measuements unde taic and windinduced ecitations wee ecoded at 5 locations beginning om pie A to pie E

3.2 nsrmenaion

The equipment used to measue the acceleation-time histoies consisted o atiaia acceleomete Figue 3a in conunction with its own data acquisitionsystem The system consisted o Knemetics SSA digital ecoding stong motionacceleogaph Two othe units contained intena acceleometes and the emainingtwo wee connected to Kinemetics FBA3 oce baance acceleometes. Each o theacceleometes was capabe o measuing acceleations o ±gs with a equencyesponse o DC -5 0 Hz Al data wee samped using a 100 H sampling ate and

stoed intenally on the SSA- then downoaded to a pesonal compute Each othese units was tigeed simultaneously using laptop pesona computes connectedto each SSA- A nomina 30 sec ecod was obtained at each location Acceleometeswee mounted in ode to measue vibations in thee othogonal diections. Toensue the blocks wee placed in evel adjustable eet and a capentes leve weeattached to each b ock Acceleometes wee connected to the data acquisitionsystem by shieded cables.

Sets o thee acceleometes wee mounted to aluminum bocks in othogonadiections. A bock was positioned at each location with the acceeometes oiented

in the vetical tansvese and longitudinal diections. To pevent any shiting o theacceleometes duing testing 5-pound bags o lead shot wee laid on top o theaceeomete bocks once in position Duing ambient vibation tests taic wasaowed to coss at noma highway speed.

8


28/152

Tesing Procere

A efeece locatio heeiafte caled the base statio, was seected based othe mode shapes fom the pelimiay fiite elemet mode at locatio 4 as showi Fiue 3b. Two of the acceleometes oe at each side of the oadway width

Fiue 3 c, emaied at the base statio 4 thouhout the testi sequece Fivetiaial acceeometes wee used at movi statio locatios. Fom the pelimiayfiite elemet aaysis, 5 locatios wee idetied to be measued to epeset thedyamic behavio of the bide tota thee wee five sets of movi statio datawith each set havi 5 movi statio locatios Tables 3.a ad 3b descibe thedesiatios of movi ad base statio acceeomete o the iht lae Tables 3aad 3.b detail the desiatios of movi ad base statio acceleometes o the eftlae. Fist five statios thouh 6 wee placed i spa A-B statios 8 thouh wee placed i spa B-C statios 4 thouh 0 wee placed i spa C-D adstatios thouh 5 wee placed i spa D-E. Data colectio bea fom pie A

to pie E o the iht lae. The same pocedue was epeated fo the left lae alsowthout atei the base statio Statios 3, ad 5 wee placed just abovethe pies A, B C D ad E espectively.

Oe set of measuemets cosisted of ecodi acceleatio-time histoy otwo base statios ad five movi statios simultaeously Afte collecti the datathe moveable statios wee shifted to the et locatios while the base statiosemaied statioay. This sequece was epeated five times to et measuemets oal statios o the othboud lae.

4 aa Analysis

Oce the data have bee dowloaded fom the fied test, a Fast FouieTasfom FFT was pefomed o each acceleatiotime histoy usi the DADiSsoftwae. The poam DADiS Data Aalysis ad Display Softwae by DSDeveopmet Copoatio Cambide Massachusetts, DADiS 995 was sed toview ad aalyze the lae amout of data The poam has the abiity to quickyaccess ad display the lae ecods of 30,000 data poits Also the poam has aetesive data hadli ad aaysis libay which was eeded fo this eseach FastFoie tasfomatio ofthe acceleatio histoies was possible i a few secods Thespeed of the poam made aalyzi ad viewi such a hue amout of datamaaeabe.

Acceeatio ecods wee tasfomed fom the time domai to the equecydomai thouh the use of the Fouie tasfom. Equatios 3 ad 3 ae themathematical defiitios of the Fouie tasfom pai. Equatio 3 . is efeed to asthe Fouie tasfom of ad the equatio 3. as the ivese Fouie tasfom

9


29/152

Pesseta 1992 ChapaandCanae 988

F(m) ! e

ft

w dw

(3 1)

(3.2)

whee f(t) = a functon of te F(r) = aptude as a functon of fequency and r ccua fequency adans pe second

Fo equatons 3 and 32 a te functon can be deved fo a fequencyfuncton o vce vesa. he pobe wth usng equatons 3 1 and 3 2 es n the factthat a contnuous functon s equed Fo dscetey saped data such as a dynac

bdge test a dffeent fo of the Foue tansfo s needed A fo of equaton31 known as the Dscete Foue ansfo DF s used when ponts of data aeknown at eveny spaced ntevas quatons 3 3 and 34 ae the dscete fos of theFoue tansfo pa

N i k n / NF " = k�O

fk e (for n=O to N-1)

f=

2

N

F

k/N L eNn=O fo k= to whee = nube of saped ponts and f set of saped ponts

(3.3)

(34)

he DF as epessed n equaton 33 s usuay the ost usefu n cvengneeng appcatons whee fequency coponents ae sought fo dsceteysaped dgted data Howeve the dect appcaton of equaton 3 3 eques

cope atheatca opeatons hs becoes pohbtvey teconsung evenfo odest ength data ecods Fotunatey thee s a nueca opeaton thateduces coputng te fo the DF substantay.

he ethod s caed the Fast Foue tansfo FF and owes ts effcency

epotaton of the peodcty and syety otgonoetc functons An FF canbe coputed n appoatey og opeatons Fo a set of 1000 data ponts theFF s appoatey 00 tes faste than the DF he st FF s attbuted toGauss n 1805 but dd not becoe wdey known unt the d 960s wth the adventof the Cooeyukey agoth. A oe copete atheatca and nuecateatent of the FF can be found n ess et a 992 and Chapa and Canae

0


30/152

988 Usng the Fast Fue Tansf FFT natua equences n theethgnal dectns wee detened Addtnal pcessng nt a we SpectaDensty SD plt whch squaes the FFT aptudes and dvdes ut the ecdlength was setes helpful n dentfyng natual fequences.

Mde shapes wee detened by plttng the ats f acceeete FFTagntude t base statn FFT agntude at the espectve lcatns alng thebdge Cpang the phase ange f an FFT fequency t the basestatn FFT phaseange detened the sgn f the agntude t be pltted nphase ut-fphasewth the base statn.

Atypcal abent vbatn acceleatnte hsty btaned n the tansvesedectn at the vng statn 6 s shwn n Fgue 3.2a. Sla te hstes aeshwn f the vetcal fgue 3.2c and lngtudnal fgue 3 2e dectns at vngstatn 6 F the tansvese dectn the FFT f the acceeatn tehsty fvng statn 6 s shwn n Fgue 32b Sla FFTs f vetcal and ngtudnaldectn tehstes ae shwn n Fgues 3. 2d and 3 2f. By bsevng the peaks fal the statns the natual fequences wee dentfed These peaks d nt awaysccu at eactly the sae fequency at al lcatns. Theefe the nube f peaksf adjacent natual fequences wee calculated. Table 33 lsts the dstbutn ffequences f acceleatn ecds btaned n lngtudnal tansvese and vetcaldectn acceleetes. Then the bdge natual fequency was dentfed as thene whch has the au nube f peaks The fequency was als fund t bebased n the de shape that flws clse t the pelnay fnte eleent deesults

Table 3 .3 als lsts the cpasn between the feld tested natual fequencywth that f the calbated fnte eeent del They ae dscussed n the fllwngsectn

35 Finite Element Moel Caliration

A lgca net step t feld testng n bdge evaluatn s t ceate an anaytcaldel whch wll celate wel t the easued dynac ppetes. Manyassuptns and delng appatns ust be ade when ceatng a pactcaldel f a bdge. F eaple a fnte eleent del eques nput f the ateappetes whch ae nheently vaable. Ths s ne nput whee the analyst can nlyake a best estate and ate adjust t atch the epeental esults

Usng esuts f the egenvaue analyss geneally the bdge del has tbe calbated t epeentally detened de shapes and fequences Apefecty cabated del wuld atch all epeentaly detened de shapes


31/152

and equencies eactly Howeve, to hope o such a peect calibation is notealistic. Theeoe, ony the most stuctually signiicant modes and equencies aeused in the mode calibation pocess. amely, the ist thee tansvese modes istthee vetica modes and the ist longitudinal mode om ield testing ae seected ascaibation tagets

aametes which wee used to coelate with the ied test include theolowing: modulus o elasticity (E o the ame elements, the be aing sping stiness,and sping stinesses o the pies nitial estimates o these paametes weeobtained om the stuctua dawings But the estimates do not account o (1constuction toleances o eos that can make asbuilt dimensions dieent omdesign dimensions, o ( actual stengths o mateials such as the actua compessivestength o concete, which aects its modulus o elasticity Caibation is peomedby adusting the stinesses and msses o the bidge membes unti an acceptablematch is obseved in the natual equency and mode shape

Since the bidge does not have a symmety along the vetical diection, it is notpossibe to obseve pue tansvese modes. nstead, tansvese eualtosionalmodes ae obtained But pue vetical mode ae obtained because the bidge issymmetic in the tansvese diection ongitudinal modes ae accompanied with littlevetica bending mainly because o the unequal pie stinesses Fo compaisonpuposes, only the tansvese components om ield testing ae taken inoonsideation o the tansvese eualtosional modes All the tansvese euatosional modes ae heeinate eeed as tansvese modes, because they have maomass paticipation in the tansvese diection

The inite element esuts o the mode shapes ae geneated at the end nodes

in the oo beams On the othe hand, due to the limited access to the actua oobeams, al measuements wee taken byplacing the instuments on the pavement justabove the oo stinges

Figue 3 .3a shows the compaison o the mode shape obtained om the test andinite eement model Athough this mode is not a pue tansvese mode, Figue 33acompaes only the tansvese components. This mode has ou hal-waves ang thelength o the bidge The distibution o undamental natual equency is given inFigue 3 3b. t can be seen om this gue that the peak in the magnitude vaiedom 0.66 Hz to 0 6 01 Hz, with a maimum numbe o peaks occuing at 0 53Hz Theeoe, 053 Hz is identiied as the undamenta equency om the ieldtest The natua equency om the inite element mode is 053 Hz nd thedeence is ony about 00%


32/152

Figue 3.4a shows the fist vetical mode with a natual fequency of 0. 8016 Hfom the test. The dstibuton of natual fequency s shown in Fgue 3.4b Themaimum numbe of peaks appeas to be at 0.806 Hz and hence ths is identifiedas the natual fequency fom feld testing The finite element model fequency is0. 80 H, and the dffeence is only about . % This mode s a pue vetical mode

with 4 halfwaves along the ength of the bidge

The taffic induced ecitation can poduce clea acceleaton ecods in thevetical diection, and the taffc combined wth wind ecitations can poduce in thetansvese dection Since thee was no ectation along the ongitudina diection,clea acceeation ecods n the ongitudina diecton wee not obtained Theefoematching the fequencies is difficult fo this mode. The fist longitudna mode shapeis shown n Figue 3.5a The natual fequency fom the feld test accodng to Figue3 5b is 1 93 H Athough the maimum numbe of peaks occus at 1 .9038 Hz themode shape coespondng to 193 H matches well. The FE model fequency s1. 853 H, and the diffeence is only about % Due to the dffeence in stiffness

of the pies, pue ongitudinal modes ae not obtained. Theefoe longitudinal modes accompaned by a small vetcal modal defomation howeve the masspaticipaton in this mode s mainly due to the longitudina defomation of the pies

Figue 3.6a shows the mode shape of the second tansvese mode. Thedistibution of natual fequency is shown in Fgue 3.6b, and the natual fequencyis identified as 0.668 H. The natual fequency fom the FE model is 0.64 H, andthe diffeence with the test is ony 0.88%. This s not a pue tansvese mode t is atansvese eualtosional mode with fou halfwaves.

The mode shape of the second vetical mode is shown in Figue 3 a Athoughthe maimum numbe of peaks occus at 1 0668 H, the fequency 1 10 Hz isselected based on ts cose match in mode shapes. The natual fequency fom thetest s 110 H, wheeas the FE model s 1.065 H and the diffeence with the testis 03% Figue 3 b shows the distibuton of natual fequency of ths mode. Themode shape consists of fou half-waves along the length of the bidge.

Figue 3 8a shows the mode shape of the thid tansvese mode Ths s atansvese eualtosiona mode with the fequency of 08016 H fom field testingand 0. 80 fom FE model The dffeence of FE model natual fequency with tests only . %. Thee ae fou half-waves n the mode shape along the length of the

bidge. Figue 3 8b shows the distibution of the natual fequency, and 08016 H isobseved at 14 stations out ofthe total 5 stations

Figue 3 9a shows the mode shape of the thid vetica mode The natuafequency of 1.3694 H is dentifed fom the test and 135 fom the FE mode. hediffeence of FE mode fequency with the test is 8% The mode shape consists offive

13


33/152

hawaves aong the ength o the dge. Fom Figue 39b it is seen that themamum o nume o peaks ocus at 1336 Hz ut the mode shape coespondngto this equency does not match we with the nite eement mode The eqency13694 s identiied as the natua equency since the mode shape coespondng tothis eqency matches ette wth the nte eement mode

14


34/152

4 General

4. FIIE EME DEIG AD

FREE VIBRAIO ALYSIS

Based n the geneal dynamic chaactestics cantileve tuss bdges and thepmty and activity the seismic nes the man bidge mdel was epected temain elastc and dsplacements wee anticipated t be small enugh t neglect themateal and gemetic nnlinea eects. Hence the cnsideatin linea elastcsmall dsplacement analysis is cnsideed t be apppiate.

Fee vibatin analysis s a key pcess in the dynamic analysis a stuctuethe esulting natual equency and mde shapes succinctly descibe the dynamicchaactestcs a cmple stuctue. The analytical mdel is calibated bycmpaing ee vbatin analysis esults with ambient vibatin measuements.

42 inite Element Mde

A thee dmensnal linea elastic inte element mdel (Fgue the mainbidge was develped n SA90 inite element analysis stwae (Wilsn andHabbullah 1 99 Develped bth the ee vibatin analysis and eathquake

espnse analyss the mdel epesents the stuctue n its cuent as-builtcniguatin. All tuss membes the supestuctue ae mdeled using tw ndedame (eam elements which have thee tanslatinal DOF and thee tatinal DOFat each nde Rtatinal degees eedm DOF membes ae included in thisbidge because the cnnectins ae iveted type that culd induce eual stessesn addtn t aial stesses Based n the cnnectin between the cncete deck andstnges it is assumed that the deck and stinges will nt cntibute t the stiness the bidge. Wall type pies ae idealized as ame elements with thei gss csssectinal ppeties

The pies A B and E ae pvided with epansin be aings while the pes Cand D ae pvded wth ed beaings The ied beangs wee mdeled by smplyestainng bth the tatinal DOF that causes bending n the lngitudnal diectinand lngtudinal tanslatin. ies and beangs ae epesented by a set spingelements that simulate the actual behav.

5


35/152

The epanon bean at the pe A and wee odeled b etablhnnode n the botto chod o the tu and the top o the pe at the bean centeand coupn all DOF ecept the lontudnal tanlaton and the vetcal bendnotaton DOF u and q The coupled node povde dect output o the elatvedplaceent between the top and botto hoe o the bean and thu ndcate

the tanlaton ha eceeded the epanon capact At the epanon bean o peB onl the lontudnal tanlaton eleaed

Whle conductn ee vbaton anal t wa ound that the odeln ope un ae eleent eulted nto le a patcpaton Th a be due tolae deence n tne and ae o ebe n upetuctue and pe oubtuctue Theeoe the pe wee eplaced b pn at the botto o bean.The pn tnee wee obtaned b appln unt dplaceent alon theappopate DOF

4. 3 Free vibraion Analysis

An eenvalue anal ued to detene the undaped ee vbaton othe tuctue The eenoluton eult n the natual ode hape and equenceothe tuctue Fee vbaton anal equed t to calbate the nte eleentodel wth the eld abent vbaton tet eaueent Secondl to peoec epone anal un the odal te-hto ethod the natualequence and the aocated ode hape ae equed o ee vbaton Feevbaton anal nvolve the oluton o the ollown eenvalue poble:

1

K u

41

whee and K ae te a and tne atce and odaldplaceent vecto The eenvalue o a ode the quae o the cculaequenc o that ode and elate to the cclcal equenc b the elaton w and elate to the peod o vbaton T b the equaton T

SAP90 ue an acceleated ubpace teaton aloth to olve theeenvalue poble The ubpace teaton ethod wa developed b Bathe n 191and a detaled dcuon o the ethod and t undaental can be ound n Bathe198 Vaou technque have been ued to acceleate the bac ubpace teaton

ethod and the patcula aloth ued n the SAP90/SAP000 poa can beound n Wlon and Tetu 1983

Tadtonall ode-upepoton anal wa peoed un a tuctueeenvecto a the ba o the anal. Reeach Wlon uan and Dcken 198ndcate that th not the bet ba o a odeupepoton te-hto anal

16


36/152

nstead a speial set o loaddependent othogonal Ritz vetos yields moe auateesults than the same numbe o natual mode shapes Ritz veto analysissgnantly edues omputing time and automatially nludes the poven numeialtehniques o stati ondensaton Guyan eduton and stati oeton due to highemode tunaton.

The eason that Ritz veto analyss yields bette esults than an equal numbeo eigenvetos is that the Rtz vetos take into aount the spatial distibution odynami loading. n at, the spatal distibution o loading seves as a statng loadveto to begin the poess o ndng appopiate Ritz vetos. Subsequent Rtzvetos ae omed based on the peeding Ritz veto and te negleted neialeets n ontast the egenvetos ae omputed om the stiness and massmaties only and theeoe annot aount o the spatial distibuton o loadingEigenvetos that ae othogonal to loading do not patipate in the stutualesponse even i they ae at o nea the oing equeny

Fo model alibation the natual equenies and the mode shapes have tobe auate theeoe eat eigenvalues(natual equenies have been etated Allthe equenies may not patipate in alulating the esponse unde seismetation kind o loading. n ode to get ull patiipation many modes have to beetated n this wok aound 450 modes wee tied to impove the masspatipation But thee was no nease in the mass patiipation Theeoe Rtzveto based (whih ae load dependent etation o eigenvalues has been aiedout This method gives moe than 90% patipation in all the thee dietons

The natual equenies and mass patiipation o the lowest 0 modes ae

pesented in Table 41 Some o the equenies and thei mode shapes have beenompaed wth the eld testng in the ealie hapte. The natual equeny o thebidge anges om 05 34 Hz to 08 Hz o the ist 0 modes, and the peod angesom 1 87 se to 0.48 se The natual equenies lsted in Table 4 1 and thei modeshapes ae used only to alibate the inite element model. They ae not used o thesesmi esponse analysis t is seen om Table 4 1 that the mass patiipaton o thest thee modes ae only in the tansvese dietion Theeoe, these thee modesae teated as tansvese modes based on the mass patiipaton pont o vewalthough thee s some tosional and vetial displaement omponent as seen omFigue 4b

Fgues 4.(a and (b show the ist mode shape in isometi and plan vewsespetively The natual equeny o this mode is 0 .5 34 Hz. The peentage o masspatiipation o this mode is about 3.6 This mode has a mamum modaldisplaement in the span C-D Based on mass patiipation this mode s identied asa tansvese mode

1


37/152

Fiues 43a and shw the secnd mde shape wth a fequency f 0 6 4Hz n ismetc and pan views espectvey. Cntay t the fst mde, ths mdehas tw adacent spans havin mdal defmatns n the same dectn. The masspaticpatn f this mde s 08% Based n mass paticpatn the secnd mde sas bseved as the tansvese mde.

Fiues 4 4a and b shw the thid mde shape with a fequency f 0 8 Hzn ismetc and plan vews espectvely. Fist tw spans have mdal defmatnn the same dectn, and the mass patcipatin f this mde s 4 .5% . Based nmass paticpatin ths mde is a tansvese mde Ths s ne f the vey mptantmdes that snificantly cntibute t the tansvese seismic mtn.

The futh mde shape n smetc eevatn and plan vews s shwn nFues 4.5a b and c espectvely The natua fequency f ths mde s 08 Hz. Based n mass paticipatin and fm Fues 45b and c t is seen that this

mde s a fist vetca mde The mass paticpatin n the vetical diectin s nly.4%

Fues 46a and b shw the fifth mde shape with a fequency f 089Hz , n the ismetic and pan vews espectvely The mass paticpatin f ths mdes 0% Based n mass patcpatin ths mde s bseved as a tansvese mde.

The sith mde shape n ismetic and plan vews is shwn in Fues 4aand b, espectvey The natual equency f this mde s 0 Hz, and the masspatcipatn s 5. 9% Based n mass patcipatin, this mde s teated as atansvese mde Fiues 4.8a, b and c shw the seventh mde shape wth a

equency f 065 Hz. The mass paticpatin s nly 0.38% Based n Fiues 48and c, ths mde is manly a vetical mde

Fues 49a b and c shw the eihth mde shape wth a fequency f . 6Hz Ma mass paticpatin .3% is in the tansvese dectin with a ittlepatcpatn f 0 % in the vetical ectin Theefe this mde s bseved as atansvese mde. The ninth mde shape with a fequency f 4 Hz is shwn nFiues 40a and b. The mass patcipatin s nly 3.86% n the tansvesedectn Ths mde s identifed as a tansvese mde

The tenth mde wth a fequency f 3 5 Hz s shwn n Fues 4 a b

and c The mass patcipatn f ths mde s 3 % in the vetical dectn and0.% in the lntudina diectin Hence it is dentifed as a vetca mde.

Fiues 4.a b and c shw the eleventh mde shape wth a fequency f.456 Hz The mass patcipatin n tansvese and vetca dectn ae 04% and063% Ths mde s a cmbnatn f vetica and tansvese mdes

8


38/152

The twelve mode shape with a fequency of 1 539 Hz is shown in Fiue 4 13aand b The mass paticipation fo this mode is 0% Based on the mode shape andmass paticipation this mode is identified as a tansvese mode with many halfwaves. Fiues 414(a ( and c show the thiteenth mode shape with a fequency

of 1 .63 Hz The mass paticipation fo this mode is 19% Based on the mode shapeand mass p aticipation it is obseved that this mode is the second dominant mode tocontibute sinificantly in the vetical ection

Fiues 415a (b and c show the fouteenth mode shape with a equencyof 1.64 Hz The mass paticipation fo this mode is 535% in the vetical diectionTheefoe this mode is obseved as a vetical mode with a little tansvese bendinThe fifteenth mode shape with a fequency of 15 Hz is shown in Fiues 4 16 ab and . The mass paticipation fo this mode in the lonitudinal diection is .3 5%and in the vetical diection is 0 3% Theefoe this mode is the fist dominant modeto contibute sinificantly in the lonitudinal diection Simila obsevations can bemade fo othe modes fom Table 4 1

The mode shapes and natual equencies discussed above consisted of all thesystem fequencies. Fo eathquake esponse analysis all these fequencies andmodes may not be ecited and theefoe all the fequencies ae not equied TheRitzvecto based method yields fequencies and mode shapes that povidesinificant paticipation in all diections. These fequencies and thei masspaticipation ae pesented in Table 4. By compain Tables 4 1 and 4 it is seenthat the modes with vey less mass paticipation in all the thee diections ae omittedby Ritz vecto based eienvalue etaction method Fom Table 4 it is seen that the

mass paticipation in all the thee diections is moe than 90% and this indicates thatmodel will ive easonable esponse unde eathquake type loadin

19


39/152

5. EISMI ESPONSE NALYSIS

5 Genera

A numbe o dieent anaytia methods have been deveoped o assessng thesesmi vuneabity o estng bidges inuding east anaysis, neast pushoveanayss apaity spetum anaysis and nonnea dynami anaysis esty et a1996) Eah appoah inopoates dieent assumptions and vaies in ompeity oappiaton. The pobem o an enginee assessing the seismi vuneabiity o a bidgestutue is to seet the most appopiate and ost-eetve method o peomng theassessment. Unde mino gound motions, a bidge wi epeiene itte ineastibehavio and thus the inea easti anaysis is suient o bdge design and

assessment o mino eathquakes A imitation o the easti anaysis method is thatthe inea anaysis oes itte inomation egading the ineasti esponse o thestutue Disadvantages o noninea dynami timehistoy anaysis ae that thestutua eements o noninea modes ae onsideaby moe ompe than that othei inea east ountepats, the numeia agoithms do not aways ensueonvegene to a physay vaid soution poessing and evauation o the outputoten eque onsideabe eot, and the esuts an be etemey sensitive to nputpaametes and stutua modes

n this wok, moda time-histoy anaysis is used beause the bdge sassumed to behave eastiay inea with sma dispaements unde the epeted

eathquake oading. The Moda timehistoy method was used instead o the esponsespetum method o the main bidge due to the impotane o the bidge and aso dueto the ak o seismi onsideations in its initia design. Time-histoy anaysis is themost sophstiated anaysis tehnique avaabe to the stutua anayst. Using thistype o anaysis aods the enginee a ompete desiption o the behavio o astutue at a tmes thoughout an eathquake Sine no stong eathquake eodsae avaiabe o the Easten US. time-histoy anayses o Kentuky bidges weepeomed using atiia eathquake eods haatesti othe ew Madid and otheneaby sesmi zones

The Moda time-histoy method o the eathquake anaysis invoves the souton

o the oowing equation o moton:

0

{


40/152

where C an K are he sysem mass amping an siffness marices, respecively an are he sysem noal acceleraion, velociy an isplacemen vecors is heearhquake moion for which he briges response has o be calculae The SAP90soware performs exac inegraion of he moal-response equaions for a near variaionof he ime-funcion beween he inpu aa ime poins. Therefore he resuls are no

epenen on he selecion of a imeinegraion inerval as in some oher mehosislon an Habibuah 199 Damping for all he moes is assume o be 5%

Timehisories represening he 50year even an he 500-year even weregenerae for he verical an wo orhogonal horional irecions in he repor by Sreee al. 1996) The 50-year even is ene as: he peak horional paricle acceleraion,a he op of rock ha has a 90% probabiliy of no being exceee in 50 years i.e. 10%probabiliy of exceeance) Likewise he 500year even has a 90% probabiliy o nobeing exceee in 500 years A recurrence rae reurn perio) can be calculae or heearhquakes which woul prouce he 50- an 500year evens

The 50-year even ha has a 10% probabiliy of exceeance correspons oASHTOs 1996) esign earhquake for highway briges. For low probabily oexceeance, he recurrence rae is approximaely Naional Highway Insiue, 1996) heraio of ime an reurn perio. Acual reurn perio for he 50-year even is 5 yearsMayes e al. 1992) Some saes require even longer reurn perios for hei esignearhquake. For example Californias Deparmen of Transporaion Calrans) uses a200year reurn perio which has a 10% probabiliy of exceeance every 250 years

For he seismic ones aecing enucky he 50-year an 500year evens ene Sree e a. 1996) correspon o he ASHTO esign earhquake an near hemaximum creible earhquake respecively For he brige locaion in his suyHenerson Couny, enucky, a ime-hisory wih peak horional acceleraion of 15%graviy represens he SHTO esign earhquake. The ime-s fo he nearmaximum creible earhquake 500year even) has a peak horional acceleraion o15%gaviy in Henerson Couny

52 Seimic Repone

The seismic response of he S1 Norhboun brige is calculae for he 50yeareahquake For he Henerson Couny brige sie peak horional berock acceleraionfor his aricial earhquake is 15% graviy as menione in Sree e al. 1996) Figure5 1) For comparison, ASHTOs map 1996) of peak horional acceleraion places heHenerson Couny brige sie in approxmaely, he 25% gravi conour for he sameprobabiliy even Earhquake uraion is 2 6 secons wih aa poins a 0005 seconinervals The inpu hisories along longiuinal, ransverse an verical irecions arepresene in Figues 525 respecively The peak groun acceleraions along

21


41/152

horiona verial an ransverse ireions are 56., 57 an 56 i!se respeively.

Sine he longiuinal ireion ofhe earhquake may no oinie wih he longiuinalireion of he brige i is neessary o analye he brige uner ieren exiaion asesas esribe in Table 5 . . ner LL exiaion ase as menione in Table 5. hehorional earhquake is appie along he longiuinal ireion of he brige, anverial earhquake is applie aong he verial ireion of he brige Similarly for oherexiaion ases he verial earhquake is onsiere o be aing in he verial ireionof he brige Only he horiona an ransvese earhquakes are reverse. On someexiaion ases, a hree ireion earhquakes are applie simulaneousy

Timehis analysis prous a very large quaniy of oupu I is iul omonior he maximum fores for al he members an maximum isplaemens a al heoins in a moa imehisory analysis for he seismi exiaion kin of oaingTherefore members an oins are selee base on heir proximiy o riia loaions.From SP90 sofware fores an momens are obaine for selee members. Sresses

are auae exernally using simple ompue programs/spreashees Table 5.2presens he ross-seional properies of members ha are selee for sress alulaion.

As an example for he L1T2V Table 5.) earhquake he ime hisory pos oransverse verial an longiuinal isplaemens a oin (Fig 2 5) are presene inFigures 5557 respeively I is observe ha he maximum ransverse isplaemeno0. ours a 2.52 ses maximum verial isplaemen of0.26 ours a 0. 705 ses,an he maimum in longiuinal ireion is 027" a 76 ses The axial fore imehisory for member Fig. 26) is presene in Figure 5. The maximum axia fore of 5kips ours a 0 ses.

For sress alulaions he axia sresses are alulae from PA an beningsresses are alulae from M/Z an M�:/Z2 M2 an M are he bening momensin he loal 2 an panes respeively. Z an Z3 are he seion moulus abou he2 an - planes respeively. Combine sresses are aulae as he sum of PA,MjZl. MZ2 wih appropriae signs o ge he maximum sresses

xia sress = oa = xial ore/reaBening sress in -2 plane a h join = ob12,= AbsolueM a Noe I Z�:)Bening sress in 2 pane a J'h join = ob; Absoue(M a Noe J ZBening sress in plane a I oin o3= Absolue(M a Noe I Z)Bening sress in plane a J' join =

obAbsolue(M a Noe J Z

)

Combine axial an bening sress

Sress a noe I o ob2 oiSress a noe J = o + on +

22


42/152

Shear sress is alulae from he shear fores in 1-2 an 1- plane i.e,

Shear sress = = { Square roo of [(SF + (SF) }/rea

The absolue maximum of sresses obaine om he maximum an minimum

responses om imehisory analysis are presene in abular form an are isusse inhe following. Table 5 liss he sresses a selee members (Figs. 2 . 2 . 7) ue oseismi exiaion ase L1T2V (Table 5 1). Due o earhquake moion aone he axialsesses are foun o be larger han he bening sresses wih a maximum of 1.69 ksi inmember 1 . Bening sresses are alulae an presene a noes I an of he membe.Table 5 . also presens he maximum of he ombine sresses om he Dea loa ±Earhquake oa (EQ) ± Thermal loa (90° F). Shear sress is foun o be very low wiha maxim u of 2. 5 ksi in member 17 5 The maximum of ombine axia an bening sressis foun o be 0.6 ksi in member 1 whih is less han he yiel srengh of seel (6 ksi).

Table 5 4 iss he sesses a selee members (Figs 2 .27) when wo of heexiaion ireions are reverse ie. uner L2T1V (Table 51) ase. xial sresses ueo seismi fores alone are foun o have a maximum of 1086 ksi in membe 1 7 ThisTable 54 aso presens he maximum of he ombine sresses from he Dea loa ±Earhquake loa (EQ) ± Thermal loa (90° F) Shear sresses are muh ess wih amaximum of 2.57 ksi in member 175. Maximum of he ombine sresses is foun o be4.7 ksi in member 27 4 whih is ess han he yiel srengh of seel

ner he seismi exiaion ase LL, he sresses aulae for seleemembers (Figs 2 . 2 7) are presene in Tabe 5.5 The maximum axial sress is founo be 165 ksi in member 1. Maximum of he ombine axial an bening sress is foun

o be 406 ksi in member 222, whih is less han he yiel srengh. Shear sress is founo have a maximum of 0. 14 ksi in member 276.

Table 5.6 liss he sresses a seee members (Figs 2.2.7) when he seismiexiaion LL22 is applie The maximum axial sress is foun o be 1.07 ksi in member17 Maximum of he ombine axial an bening sress s .2 ksi in member 222 whihis far less han he yiel sress of seel. Shear sress is foun o have a maximum of 0.085ksi in member 276.

For he seismi exiaion ase TT he sresses a selee members (Figs 2 -27) are presene in Table 5.7. The maximum·axia sress is foun o be 106 ksi in

member 277 Maximum of he ombine axial an bening sress is 04 ksi in member04, whih is ess han he yiel srengh of see Shear sress is foun o have amaximum of 02 ksi in member 175

Table 58 iss he sresses a selee members (Fgs. 227) when he seismiexiaion TT22 is appe The maximum axia sress is foun o be 098 ksi in member

2


43/152

22. Te maximum ofte combine axia an bening stresses is . 71 ksi in member 176which is ess than the yiel stress of steel The sear stress is foun to have a maximumof 0.22 ksi in member 276.

The stresses at selecte members (Figs 2-2.7) ue to a ifferential temperature

of 90°F are presente in Table 5. 9. The coefcient of thermal expansion for steel is takenas 6.5 x 10F Maximum axial stress is foun to be 1 ksi in member 1 Maximumshear stress is obtaine as 02 ksi in member 179. Combine stress from axia anbening is 222 ksi in member 1

Table 5 .10 lists the stresses at selecte members (Figs 2 . 2 7) ue to the selfweight of the brige Maximum axial stress is foun to be 1 1.5 ksi in member 102Maximum sear stress is obtane as 2.26 ksi in member 175 Combine stresses fomaxia an bening stresses have a maximum of 06 ksi in member 221

In previous calculations the stresses prouce were checke purey from themateral yiel point of view Uner earthquake loaing truss members may experiencetensile force at one time interva an compressive force at some oter time interva

_(5)

F

Therefore it is necessary to check for the buckling of truss members. Since the brigetruss members are subecte to axial forces an bening moments the equations (102)

to (10-) from ASHTO are use to check whether they satis the inequality conition

ASHTO Eq. (102)

{( I

ASHTO Eq. (10) At points of support

ASHTO Eq (10) Euer Buckling Stress

2

(5.2)

(5.4)


44/152

r (55) _

In Table 5. and 5.2, he sresses are heked by also onsidering he buklingofhe member for he earhquake exiaion ases LT2V and L2TV respeively Iis seen ha he inequaliies given in equaions 02 and 0- are saised and henehere will no be any member failure due o ombined axial and bending sresses

The displaemens a seleed nodes (Figs. 2 -2 .7) are presened in Table 5 . fordifferen exiaion ases (Table 5.) Maximum displaemen in he longiudinal direionis 0.6" a oin 9 under LL ase Maximum displaemen in he ransverse direion is05" a oin 0 under LT2V ase. Maximum displaemen in he verial direion is0.7'' a join 62 under LL ase.

Under sai dead load and emperaure he displaemens a seleed joins (Figs.22 7) ae sed in Table 5 Due o a emperaure differene of 90F maximumdisplaemen in he longiudinal direion is 2." a he join The ransversedisplaemen is maximum a oin 0 is 6 Maximum verial splaemen is 2" ajoin 62 Due o dead load maximum longiudinal displaemen is 0.6" a join Transverse displaemen is wih a maximum of 05 a join 0 The maximum vetialdisplaemen is 0.0 a oin

Maximum and minimum base shears obained for he bridge are lised in Table

5 5. These values are presened for dieren exiaion ases lised in Table 5. Then,based on he ranslaional siffnesses of he piers longiudinal and ransverse seismifores on op of he pier are alulaed and presened in Table 5. 6

5.3 Capacy/Deman Rao an Rero for he Man Brge

Sine he supersruure of he bridge is onneed o he subsruure hroughbearings, i is neessary o hek hese bearings agains anhor bol shear failure. Table5.6 liss he available anhor bol shear apaiy (VJ and seismi fores on eah pier Theanhor bol apaiy V is alulaed by assuming he shear srengh of he bol as 2697

ksi. The resulan of seismi fore is alulaed as he square roo of he sum of squares(SRSS)of he longiunal and ansvese seismi fores. Then he seismi demand () isalulaed by muliplying by .25 as per FHWA Rettting manual l he piers haveC/D raio less han .0 Therefore, addiional anhor bols or seismi isolaion bearings arerequired

25


45/152

The expansion bearings at piers A B an E are roler bearings Hence competelossof-span may not occur Therefore bearing ispacement capacity/eman ratio is notcacuate

5 Retrof for he Man Brge

From the previous sections, it is clear that a the bearings are be strengtheneto resist the 05g earthquake corresponing to 50-year event It is suggeste thataitiona anchor bots may be provie to retrot the bearings at piers A, B, C, D an E.Alternativey the bearings may be repace with seismic isoation bearings Therecommenations are liste in Tabe 5. 16 an in Figures 59 through 5 1

26


46/152

jROAH AS

61 Genera

The northboun S brige over the Ohio river consists of straight approachspans on Kentucky an Iniana sies The approach briges towars the Henerson, Ksie an Evansville I sie are shown in Figures 6 a The plan an elevation of theEvansville, I an Heneson, K approaches are shown in Figures 62 an 6,respectively The Evansville, I approach, consists of simply supporte spans with atotal length of 06 , an the Henerson, I approach consists of 5 simple spanscovering a total length of 20 6 which provies a clear 0 wie roaway an 2 wiesie walk on either sies The spans in both the approaches are supporte on piersthough xe bearing an expansion bearing as inicate in gures 6 2 an 6 ll the

piers an abutments are foune on friction piles which exten up to 60 to 00epening on the soil resistance.

The Evansville, I approach has 5 eck truss spans of each 50 an grer spansof each 00 The Henerson K approach has eck-truss spans of each 50', 2 girerspans of each 00 an 0 girer spans of each 6 The 50 -spans are mae of two ecktype parallel chor trusses space at 2 c/c The thick concrete eck is supporte on asteel stringer an oor beam system The superstructure in the 00spans is similar to50 spans except that the trusses are replace with plate girers In the 6 spans, theconcrete eck is irectly supporte by -nos. of steel girers Isection)The reinforceconcrete brige piers have rectangular sections an taper along the height with a batter

of per foot lengh The sub-structure in the approach spans is mae with class concrete

62 Srctra Moeng

The approach spans on the Evansville, I sie an Henerson, K sie areieae as simple structual units epening on the type of bearing attachment ofsuperstructure mass) to the pier top These iealize units are assume to actinepenently when subecte to motion in the longituinal irection of the brige These

simplie systems are treate as single egree of freeom systems (SDOF) formathematical moeling of the brige in the longitinal irection The moels areesignate as EV-EV6 for the Evansville, I approach an HE-HE for theHenerson K approach The etails of the components of these moels are given inFigure 6 an 65 respectively. The mass of the SDOF systems is assume to becontribute by the mass of the superstructure an one-thir mass of the pier The stiffness

2


47/152

s th longtunl trnslton stffnss of th prs tht s lult usng 3 Th

mouus of lstt of onrt s ssum s 25 ks Th vrg momnt of nrtof th pr s us for th stnss lulton.

An mportnt pont to b not t ths tm s tht thr xsts ot of unrtntn quntng th sol-strutu (p founton) ntrton fft n th stnsslulton Du to th unvblt of tl st sol nvstgtons, rprsnttvmols wth mxmum n mnmum stffnss r opt n th fors nspmnts lultons rsptv. Th mxmum stffnss s obtn b ssumngth pr s x t th bottom of pl p Th mnmum stnss s obtn b ssumngth pr s xtn up to n mgnr pth qu to hf-p-lngth n x t thtvl. Th xtn ngh s ssum to hv th sm xurl proprts s tht of thpr Ths smpl prour for stnss stmton hs bn vlt to rprsnt thmost st n most xbl mol n hn opt for th onsrvtv stmt ofssm fors n splmnts n ths stu

Th wght lutons for th suprstrutur n th 150 100 n 6 spns sgvn n Tbls 61. Th mnsons n ston proprts of th pr n th stffnss(mxmum n mnmum) n th longtunl rton lutons for l th mols nth pproh spns r lst n Tbl 62. Th mss nlus onthr mss of th prn tht of th suprstrutur tth to th pr b x brng.

6 3 Sesmic Response Analysis

Sn th brg s lot n Hnrson ount, K t s nl unr ssmmoton orrsponng to 0.15g rthquk of th 50r vnt. Th rspons spt ofths rthquk s prsnt b Strt t l. (1996) Th stu of mg to mutspnsmpl brgs rvls tht longtunl ssm wvs hv us mor mg thntrnsvrs Zmmrmn n Brttn 199). In ths work, ssm nlss s pformto trmn n lossof-spn u to xssv longtunl spmnt or shr flurof th brngs In ths work, ssm nlss of th smpl SDOF mos for thpproh spns s rr out usng th rspons sptrum mtho

Th rspons sptrum mtho s thnqu for obtnng th soluton of thoupl sonorr, nr ffrntl qutons of moton tht govrn th for

vbrton of brg Ths mtho nvovs n ntl gnvlu nlss to trmn thntur quns n mo shps of th brg. Th orthogont of th mo shpswth rspt to th mss stffnss n mpng mtrs s thn us to unoupl thqutons of moton. Th pk rspons ssot wth th sng-grof-omsstm rprsnt b h of th unoupl qutons of moton s obtn through thus of n lst rthquk rspons sptrum. stmt of th mxmum rspons

2


48/152

of h sruur is rmin by ombining h pak rsponss of h iniviua mosbas on saisia prours

Th rsus of h sismi anaysis ar uii o rmin h possibii of anyoss-of-span u h xssiv ongiuina ispamns a xpansion barings orshar faiur of anhor bos in x barings Sismi anaysis is arri ou using hrspons sprum mho

Th naura qunis of h SDOF mos ar prsn in Tab 6 wihorrsponing masss an siffnss. Th aua naura qunis rang om 26H o 12 5 for h mo wih maximum siffnss an 0 H o 1 5 H for h mowih minimum siffnss

Th rspons spra for h Hnrson K is shown in Figur 66 This sponsspra orrspons o a amping of 5% Th si soi ofin S is assum as 1 5 for

h auaion of h sismi rspons oin C bas on AASHTO (Div IA sion), C,=

12

P

)(S

.

Th Cis imi o 2 5 i 05 as pr ASHTO In h auaion of

fors, for a mos C is govrn by his maximum imi of 05 Sismi fors anispamns ar alua an prsn in Tab 6. Th aua ispamnsrang from 1 o 4" Th sismi fors rang from 94 kips o 664 kips

6 Capaciyeman Raio

For boh h approah spans h baring for apaiy V() /man V() raios,hav bn aua as pr sion A4 of HWA Seismic Retrofitting Manua foHighway Bridges (Buk a 1995) Th sismi for man V() is onsir ash maximum of 125 ims h sismi for an 0.2 ims h wigh of hsuprsruur Th anhor bo uima shar apai V() is aua by assumingh shar srngh of bo maria as 19.0 ksi (for ksi s) Th Capaiy Dmanraios ar ss han 10 for hirn ou offory-wo suppors having barings Thbarings a hs oaions ar o b rro wih aiiona anhor bos o hbarings n o b rpa wih sismi isoaion barings so as o wihsan h forsu o an arhquak

For boh h approah spans, h ansion baring ispamnCapaiy/Dman raios (rb) ar aua as pr sion A.42 of FHWA sismiRroing Manua for Highway Brigs (Buk a 1995) Th C/D raios araua aoring o boh mho 1 an mho-2 Th xpansion barings a pir S6 S5 in h Hnrson K approah span ar of siing pa p Th movmn nh ongiuina irion a his yp of baring uring an arhquak is imi An

29


49/152

hrfor, only mho is us for calculaing h isplacmn Capaciy/Dman raiosa hs barings ll ohr xpansion barings ar of rollr yp, an boh mhos arus for C/D caculaions Th baring isplacmn Capaciy/Dman raios r argrar han 10 for all h xpansion barings an hnc lossof-span canno occur uo h raiv isplacmns occurring u o h proc arhquak

For h Evansvill IN approach, h baring Capaciy Vc)/Dman V) raiosan isplacmn Capaciy/Dman raios ar prsn in Tabls 64 an 65rspcivly Similarly for h Hnrson K approach spans h baring CapaciyVc)/Dman V) raios an isplacmn Capaciy/Dman raios ar prsn inTabs 66 an 6.7 rspcivly.

65 Retrofi Recouendaions

From h prvious scions i is clar ha hirn ou offory-wo suppors having

x barings ar o b srnghn o rsis h 015g arhquak corrsponing o 50yar vn a Hnrson, K I is suggs ha aiiona anchor bols may bprovi o rro hs barings or all hs barings may b rplac wih sismicisolaion barings

For h Evansvi, IN approach spans h rro rcommnaions for h xbarings ar prsn in Tabl 6 an in Figurs 67 hrough 612 Similarly, for hHnrson, K approach spans, h rro rcommnaions for h x barings arprsn in Tabl 6.6 an in Figurs 6 1 hrough 6 16.

30


50/152

CNUNs AND cMMNDAIONs

7.1 General

The US4 norhboun brige over he Ohio river may be subjee o fuureearhquakes. Therefore i is imporan o evaluae he brige uner he projee seismimoion. In his suy sine he brige is loae in Henerson enuky 015gearhquake for he 50-year even is applie epening upon he imporane ofhe brige,i has been eie o use more rigorous mehos for he evaluaion of he main brgean simplie mehos for he approah spans

7.2 Main Bridge

The seismi evaluaion of he main brige onsise of el ambien vibraionesing nie elemen moeling an seismi response analysis using he moal imehisory meho. iel esing was mainly arrie ou o ieni he naural frequeniesan heir moe shapes. These frequenies an moe shapes have been ompare wih heresuls from he nie elemen moel Comparisons have been performe for hreeransverse moes hree verial moes an one longiuinal moe

A hree imensional nie elemen moel was evelope wih frame elemens anspring elemens This moel has been alibrae wih he el es for naural equeniesan moe shapes. requenies from he el es for he rs moes n he ransverse,verial an longiuinal ireions are 0544 006 an 1.92 H respeively.

requenies from he nie elemen moel for he rs moes in he ransverse verialan longiuinal ireions are 0.542 0.0 an 1.56 H respeively Reasonableagreemen beween he el es an he nie elemen moel has been obaine.

Seismi response analyses have been arrie ou using he moal imehisorymeho. isplaemens of selee joins an sresses for selee members have beenalulae The resuls are also presene for ifferen seismi exiaion ases byreversing he seismi exiaion ireions. Sresses for selee members are alsopresene for ombine earhquake ea loa an hermal loas or he selee joinsuner earhquake exiaion, he maximum isplaemen in he ransverse verial anlongiuinal ireion was foun o be 0.5" 04 an 0.6 , respeively Maximum ofombine axial an bening sress in he member is foun o be 4. ksi. These sressesare less han he yiel sress of seel an hene maerial yieling may no ou Beningsresses have been ombine wih axial sresses by onsierng he bukling of members was foun ha for he selee members bukling failure will no our

31


51/152

Bearng force Capacy/Deman raos have been calculae for he bearngs a allhe pers All he pers have C/D raos less han 1.0 an hence rero s requre n heform of aonal anchor bols ernavely, he exsng bearngs may be replace whsesmc solaon bearngs The recommenaons are presene n Table 516 an nFgures 59 hrough 5.

73 Approach Spans

The S1 norhboun brge has approach spans on he enucky an Inanases Mos of he approach spans are sngle-span wh expanson bearng a one supporan e bearng a he oher Therefore sngle-egreeof-freeom moels were use alongwh response specrum meho for he sesmc response analyss Response analyss hasbeen carre ou only n he ongunal recon of he brge an maxmumspacemen an force responses have been calculae

A hreen ou of forywo suppors havng xe bearngs n boh he approachspans, orce Capacy/Deman raos were less han .0 herefore, rero n he formof aonal anchor bols or replacng he exsng bearngs wh he sesmc soaonbearngs s recommene Dsplacemen Capacy/Deman raos were greaer han onefor all suppors an hence loss-of-span canno occur n boh he approach spans

The rero recommenaons for he vansvlle N approach spans are presenen Tables 6. an n Fgures 6.7 hrough 62 for he suppors havng xe bearngsSmary, for he Henerson K approach spans he rero recommenaons arepresene n Tables 66 an n Fgures 61 hrough 616 for he suppors havng xebearngs

2


52/152


53/152

Hark I.E D. Die C Hll an M.W. Guo Seismic Evaluaon an Rero ofBrges Research Repor TC965 enucky Transporaon Cener nversiy ofenucky, 199.

Harik, I. E D L. len R L. Sree M.W. Guo R.C. Graves, J. Harrison an M J.

Gawry (199a) Free an Ambien Vbraion of Bren-Spence Brge ASCE J. ofSruc Engrg 12(9) 1262126

Hark, I.E D. L . len, R. L. Sree M W Guo, R.C Graves, J Harrison an M JGawry(199b) Sesmc Evauaon ofBren-Spence Brge ASCE J. ofSruc Engrg12(9) 1269125

Hark, I.E. , C.M. Maasamy D Chen, L. Zhou Suerer R Sree an D. L en, Sesmic Evaluaon of he Ohio River Brige on S51 a Wicklie K ReseachRepor TC920 enucky Transporaon Cener nversiy of enucky, 199

Huson D.E. (19) Dynamc Tess of FullScale Srucures Journal of heEngneering Mechanics Dvision, Vo 10, No EM6 pp 1141-115

Mayes, R.L e a. (1992) ASHTO Sesmc Isolaon Desgn Requremens forHghway Brges Jua f Stuctua Engneeng Vol 11, No 1 pp 2404.

Naional Highway Insiue (NHI) Course No. 106, (1996) Sesmic Brige DesignApplcaons Noes from Sessions 1 & 2.

Nuli OW., an R.B. Herrman (19) Sae-of-hear for assessng earhquake

hazars n he nie Saes Repor 12 Creible earhquakes for he cenra neSaes .S. rmy Corps of Engneers Mscellaneous Paper S-1, 99pp.

Obermeier, S.F. PJ Munson C.A Munson J.R Marn AD.Franke, TL.You, anE.C.Pon (1992) Liquefacion evience for srong Holocene earhquakes n he WabashValley ofnana-Ilinois Seismological Research Leers6, 215.

Paure, P, Proux, J an Talbo M (1995), Dynamc Tesing Proceures forHighway Briges sng Trafc Loas Jua f Stuctua Engneeng Vol. 121,No 2 pp. 626

Press WH., e a., (1992) Numeca Recpes n ORTRA The At f ScentfcCmputng 2Eon Cambrge nversy Press New York New York, chaper 12

Presly MJN , F Sebe an G. M. Calv Seismc Design an Rero of BrgesJohnWley & Sons Inc, 1996

Saii, M, Dougas B an Feng, S, (1994), Presress Force Eec on vbraionGrequency of Concree Briges Jua f Stuctua Engneeng Vo 120 No. , pp22-221


54/152

Shahawy, M.A, (995), Non Desucive Sengh Evaluaion o Flora Biges,Poceeings o SPIE Nonesucive Evaluaion o Aging Inasucue Coneence,Oaklan, Calionia, June, 995

Shelley, S.J, e al, (995), Dynamic Tesing (ibaion alysis) o Highway

Biges, Noes Pesene a he Nth-Ameican Wkshp n nstmentatin andVibatin Anaysis f Highway Bidges Cincinnai Ohio, July, 995

Sove, CW an Homan, J.. (99) Seismiciy o he nie Saes 5699(Revse), .S. Geological Suvey Poessional Pape 52 4 p.

Taylo, B., RB. Hemann, MW Hambuge, G. Pavlis A J

Seismic Evaluation of the US41 Northbound Bridge Over the Ohio Ri

Documents