132 Sideris Aref Filiatrault 7NSC Paper Final

7/24/2019 132 Sideris Aref Filiatrault 7NSC Paper Final

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1. Introduction.....................................................................12. System Description...........................................................2

2.1. Hybrid Sliding-Rocking Segmental Joints and Members. .23. Experimental Validation Shake Table Testin....................!

3.1. Specimen Description..................................................43.2. Test !ec"tion and Res"lts...........................................#3.2.1. Results from a Single Test...........................................................................63.2.2. Eects of System / Excitation Parameters..................................................83.2.3. Post-Testing ns!ection............................................................................. 1"

!. "onclusions....................................................................11#. $ckno%ledments...........................................................12

Seismic Test: S1_SC_M2_YZ

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EXPERIMENTAL INVESTIGATION OF THE SEISMIC

PERFORMANCE OF HYBRID SLIDING-ROCKING

POST-TENSIONED SEGMENTAL BRIDGES

Petros Sideris1, Amjad J. Aref1, and Andre Filiatralt1

1!ni"ersit# at $ffalo, T%e State !ni"ersit# of &e' Yor(, $ffalo, &Y, !.S.A.

ABSTRACT:

)n t%is *a*er, t%e no"el conce*t of %#+rid slidin-roc(in /S0 *ost-tensioned semental mem+ers for seismic

a**lications in +rides is *resented. Fndamental com*onents of t%e /S0 mem+ers are t%e /S0 semental joints

co*led 'it% internal n+onded *ost-tensionin PT. T%e /S0 joints can *otentiall# e%i+it slidin and3or roc(into mitiate t%e a**lied seismic loadin. T%e joint res*onse is controlled +# t%e eometr# of t%e PT s#stem, '%ic%

can follo' linear or nonlinear la#ots alon t%e mem+er lent%. T'o distinct t#*es of /S0 mem+ers are considered4

t%ose 'it% sli*-dominant joints and linear PT eometr#, intended for +ride s+strctres, and t%ose 'it% roc(in-

dominant joints and nonlinear PT eometr#, intended for +ride s*erstrctres. A series of s%a(e ta+le tests

"alidated t%e seismic *erformance of t%e *ro*osed s#stem.

Keywords: segmental construction; seismic testing; bridges; post-tensioning; sliding; rocking

1. INTRODUCTION

Precast concrete semental +rides are com*osed of mem+ers t%at consist of a nm+er of

sements *ost-tensioned toet%er +# se"eral, t#*icall# +onded, tendons. S%ear (e#s and e*o#

ad%esi"es are sed at t%e semental joints to *ro"ide resistance aainst s%ear slidin andtension o*enin3se*aration. T%is a**roac% emlates t%e cast-in-*lace concrete s#stems and is

intended to ma(e semental +rides res*ond as if t%e# 'ere monolit%ic.

5"er t%e *ast 67 #ears, t%e nm+er of *recast concrete semental +rides %as increaseds+stantiall# +ot% in t%e !nited States and arond t%e 'orld, mainl# de to t%e ad"antaes t%atsemental constrction offers com*ared to t%e traditional cast-in-*lace tec%ni8es. T%ese

ad"antaes *rimaril# relate to: i %i%er constrction 8alit#, since t%e sements are constrcted

in *recast *lants nder %i% 8alit# control, and ii ra*id constrction, considerin t%at as soonas t%e sements are deli"ered to t%e constrction site, onl# assem+l# and *re*aration of t%e joint

connections are re8ired. T%e sinificant redction of t%e on-site constrction time a"e t%is

met%od, o"er t%e #ears, t%e name 9Accelerated $ride Constrction A$C.;es*ite t%e e"ident ad"antaes t%at *recast semental +ride s#stems offer, t%eir

a**lication %as +een limited onl# to lo' seismicit# areas, *rimaril# de to t%e fact t%at t%eir

seismic *erformance is larel# n(no'n. )n t%is *a*er, a no"el semental A$C s#stem for

+rides, intended for moderate and %i% seismicit# areas, is *resented and its seismic*erformance is "alidated e*erimentall#. T%e *ro*osed +ride s#stem consists of %#+rid slidin-

roc(in /S0 *ost-tensioned semental mem+ers Sideris 2712, '%ic% incor*orate /S0

semental joints and internal n+onded *ost-tensionin. T%e conce*t of /S0 mem+ers is"alidated t%ro% a series of s%a(e ta+le tests condcted in t%e Strctral


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T%e o+jecti"e of t%is *a*er is to *ro"ide onl# a +rief *resentation of t%e *ro*osed /S0

mem+ers. A com*lete *resentation of t%e /S0 conce*ts and detailed descri*tion of t%eir

e*erimental and nmerical "alidation is *ro"ided in Sideris 2712.

2. SYSTEM DESCRIPTION

2.1. Hybr! S"!#$-R%&'#$ S($)(#*+" ,%#* +#! M()b(r

T%e /S0 mem+ers com+ine t'o fndamental com*onents: i /S0 semental joints, and

ii )nternal n+onded *ost-tensionin PT of linear or nonlinear eometr# alon t%e mem+er

lent%. T%e /S0 joints are sim*le friction-t#*e connections defined +# direct *lane srface-to-srface contact +et'een adjacent sements 'it%ot s%ear (e#s. T%e /S0 joints tili>e relati"e

sement-to-sement slidin joint slidin and a* o*enin joint roc(in to mitiate t%e a**lied

seismic loadin. At t%e sement ends adjacent to t%e joints, t%e dcts accommodatin t%e

n+onded PT s#stem are s+stitted +# dct ada*tors, '%ic% are *ieces of t+in of larerdiameter t%an t%at of t%e dcts. As discssed +elo', t%e dct ada*tors control t%e am*litde of

joint slidin and t%e +earin tendon forces. T%e res*onse mode of an /S0 joint for a i"ena**lied loadin de*ends on t%e eometric *ro*erties of t%e joint and t%e frictional *ro*erties att%e joint interface. T%e s%ear resistance, VR,s, at t%e joint interface is i"en +#:

( ),R s a PTV N N= +

'%ere is t%e coefficient of friction at t%e joint interface, Na is t%e a**lied aial force

com*ressi"e, andNPTis t%e total a**lied PT force com*ressi"e. T%e resistin moment aainst

joint roc(in,R,r, is i"en as:

( ), ,2

R r c c min a PT

d a d N N

= +

'%ere dis t%e cross-section de*t%,dc,minis t%e minimm de*t% of t%e contact interface and acis a*arameter accontin for t%e stress distri+tion o"er t%e contact interface, 'it% ac ?136, [email protected]%e minimm de*t% is determined from damae control criteria nder ltimate loadin or elastic

res*onse conditions. Similarl#, ac 136 re*resents t%e case of trianlar stress distri+tion

elastic res*onse, '%ile ac 132 re*resents t%e case of t%e e8i"alent niform stress distri+tionat ltimate loadin conditions. $ot%NaandNPT%a"e +een assmed to *ass t%ro% t%e ais of

s#mmetr# of t%e cross-section.

For a sli*-dominant joint, t%e a**lied joint s%ear, Va, reac%es t%e s%ear strent%, VR,s,+efore t%e corres*ondin a**lied moment,a, reac%es t%e resistin moment,R,r. T%e resltin

slidin ma# contine ntil t%e tendons come in +earin contact 'it% +ot% t%e to* and +ottom dct

ada*tors at t%e joint interface see Fire 1 +. )n t%at case, t%e slidin ca*acit# of t%e joint %as+een reac%ed and a**lication of additional loadin cold onl# case joint roc(in, as s%o'n in

Fire 1c. T%e slidin ca*acit# of t%e joint is controlled +# t%e difference in diameter +et'eent%e dct ada*tors and t%e PT tendons. ;e to t%e simlatemos a**lication of moment, aial and

s%ear force e.., at a *ier joint, *artial a* o*enin roc(in can occr drin joint slidin.For a roc(in-dominant joint, t%e frictional resistance at t%e joint interface, VR,s, is ne"er

reac%ed. T%s, t%e res*onse initiates and contines 'it% roc(in. )f, drin *artial a* o*enin

dc B dc,min, '%ere dc is t%e contact de*t%, slidin initiates i.e., transition from roc(in toslidin, t%e joint is considered to +e sli*-dominant. T%is *%enomenon can occr in cases of

*ressre-de*endent coefficients of friction at t%e joint interface, as o+ser"ed +# Sideris 2712.

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Joint slidin *ro"ides ener# dissi*ation 'it% small damae t%ro% friction. Self-

centerin drin joint slidin is moderate, since re-centerin forces are onl# *ro"ided +# t%e

+earin contact of t%e tendons 'it% t%e dcts and dct ada*tors, '%ic% is acti"ated after some*rescri+ed slidin %as +een reac%ed. T%ese forces are maimi>ed '%en t%e joint slidin

ca*acit# is reac%ed i.e., '%en t%e tendon comes in contact 'it% t%e to* and +ottom dct ada*tors

at t%e location of t%e joint, as s%o'n in Fire 1+.Joint roc(in *ro"ides %i% self-centerin t%at deteriorates at larer roc(in rotations de

to concrete crs%in at t%e joint edes. T%e ener# dissi*ation from joint roc(in is lo', since

concrete damae and tendon #ieldin are t%e onl# ener# dissi*ati"e mec%anisms of t%isres*onse mode.

T%e res*onse of /S0 joints is directl# inflenced +# t%e eometric la#ot of t%e PT

tendons alon t%e mem+ers lent%. T#*icall#, strai%t tendons allo' for some *rescri+ed joint

slidin to occr +efore +earin forces are acti"ated. 5n t%e contrar#, cr"ed tendons a**l# lare+earin forces, e"en for minor joint slidin. T%s, linear or nonlinear PT eometr# can +e sed as

a desin strate# to *artiall# restrain joint slidin, sc% as in s*erstrctres, for '%ic% joint

slidin is ndesira+le.

T%e /S0 mem+ers ma# inclde se"eral joints alon t%eir lent%. $ased on t%e t#*e of/S0 joints and t%e eometr# of t%e PT s#stem, t'o distinct t#*es of /S0 mem+ers are

considered %erein: i /S0 mem+ers 'it% sli*-dominant joints and linear PT eometr#a++re"iated as /S0-S; mem+ers, intended for s+strctres, and ii /S0 mem+ers 'it%

roc(in-dominant joints and nonlinear PT eometr# a++re"iated as /S0-0; mem+ers,

intended for s*erstrctres. T%e seismic res*onse c%aracteristics of /S0 mem+ers are dictated+# t%e res*onse *ro*erties of t%e corres*ondin dominant joint res*onse modes.

A major difference in t%e res*onse of /S0-S; mem+ers o"er t%at of monolit%ic and

roc(in-onl# semental mem+ers is t%eir in%erent ca*a+ilit# of *ro"idin ener# dissi*ation

t%ro% joint slidin. For seismic a**lications, t%is is an attracti"e *ro*ert# t%at can eliminate t%eneed for s**lemental ener# dissi*ation, t#*icall# *ro"ided +# eternal de"ices in roc(in-onl#

mem+ers. Frt%ermore, *otential residal joint slidin is not associated 'it% strctral damae

and cold *otentiall# +e restored +# "arios means Sideris 2712.)t is noted t%at t%e roc(in-dominant joints of /S0-0; mem+ers differ from

con"entional roc(in joints in t%at: i t%e# do not inclde s%ear (e#s, and ii t%e# are sed in

s*erstrctres nli(e roc(in joints t%at %a"e onl# +een considered in s+strctres.

a + c

Fire 1. Sli*-dominant /S0 joint: a !ndeformed confiration, + Slidin ca*acit# reac%ed, and c 0oc(in

res*onse, after slidin ca*acit# %as +een reac%ed

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. EXPERIMENTAL VALIDATION / SHAKE TABLE TESTING

T%e seismic *erformance of t%e *ro*osed /S0 mem+ers is e"alated t%ro% a series of

s%a(e ta+le tests on a lare-scale sinle-s*an +ride s*ecimen.

.1. S0(&)(# D(&r0*%#

T%e e*erimental s*ecimen 'as a lare-scale D1:2.6E sinle-s*an sinle-cell +o irder

*recast concrete semental +ride 'it% +ot% of its s**orts o"er%anin at e8al lent%s of 2G

of t%e lent% of t%e s*an. T%e test s*ecimen re*resented t%e mid-s*an of t%e *rotot#*e fi"e-s*ansinle-cell +o irder concrete +ride considered +# Meall# et al. 2772. T%e lent% of t%e

s*ecimens s*erstrctre 'as H1.E ft 1I.E m 'it% a *ier-to-*ier distance of 1.E ft 12.E m.

T%e %ei%t of eac% *ier incldin t%e ca* +eam, +t not t%e fondation +loc( and t%es*erstrctre reac%ed 11.E ft 6.H m. T%e s*ecimen is s%o'n monted on t%e dal s%a(e ta+les

of Soidal cross-section

'%ic% 'ere *ost-tensioned toet%er +# 12 internal n+onded tendons4 17 %ar*ed-s%a*ed and t'ostrai%t located at t%e to* flane.


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Fire 6. Post-tensionin s#stem 1 12, 1 2. cm: a S*erstrctre K ard considered 'as associated 'it% a site in t%e estern !nited States, '%ile t%e"ertical %a>ard 'as ta(en as 236 of t%e %ori>ontal %a>ard, '%ic% is a t#*ical assm*tion in

*ractice, as stated in t%e ATC3MC


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seismic tests e"alated t%e s#stem seismic *erformance 'it% res*ect to se"eral seismic %a>ard

le"els, site-to-sorce distance F-F "s. &-F motions, and s*atial "aria+ilit# of t%e rond motion

in*t. T%e considered seismic %a>ard le"els inclded +t 'ere not limited to t%e ;esin


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i.e., at smaller dis*lacements res*ond 'it% joint slidin at se"eral joints, '%ile as t%e

dis*lacement demand increases, joint roc(in is initiated, *rimaril# at t%e +ottom joints. As a

reslt of t%e initial joint slidin, /S0-S; mem+ers e%i+it %i%er ener# dissi*ation ca*a+ilitiesat smaller dis*lacements, +t moderate self-centerin ca*acit#. )n contrast, t%e s+se8ent joint

roc(in res*onse redces t%e ener# dissi*ation ca*acit# of t%e /S0-S; mem+ers, +t

considera+l# en%ances t%eir self-centerin ca*a+ilities. T%e joint slidin %#steresis i.e., joints%ear "erss joint slidin and joint roc(in %#steresis i.e., joint moment "erss joint roc(in at

t%e t'o lo'er joints of +ot% *iers are *resented in Fire a and +, res*ecti"el#. T%e joint

identification, J


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roc(in %#steresis at mid-s*an, s%o'n in Fire c, t%e roc(in mode e%i+ited %i% self-

centerin ca*acit#, '%ic% reslted in nelii+le residal deformations, as 'ell as lo' ener#

dissi*ation *ro*erties.

3.2.2. Effects of Excitation Parameters

T%e effect of some ecitation *arameters on t%e s#stem res*onse 'as identified t%ro%

t%e series of s%a(e ta+le tests. )n t%e *lots t%at 'ill +e *resented in t%is section, t%e inde 9)refers to initiali>ed from >ero dis*lacement %istories at a sinle test, '%ile t%e inde 9A;

refers to dis*lacement sinals incor*oratin t%e accmlated deformations from all *recedin

tests.

ard =e"el

For seismic %a>ard le"els 'ere considered, namel# =o' ;< Poard. T%is com+ination re*resented t%e d#namic ca*acities of t%e s%a(e ta+les in t%e

%ori>ontal and "ertical directions simltaneosl#.For t%e s+strctre, t%e *ea( dis*lacement res*onse of t%e s#stem increased 'it% t%e

seismic intensit#, '%ereas t%e residal dis*lacement res*onse maintained "er# lo' "ales, as

s%o'n in Fire H, '%ic% *resents *ea( and residal dis*lacement "ales from t%e fi"e motionsof t%e far-field ensem+le. T%e lateral res*onse of t%e east *ier reac%ed a maimm *ea( "ale

t%at eceeded H. D1H. cm, DG drift ratio, '%ile t%e residal deformation 'as

a**roimatel# 1 D2. cm, D7.IG drift ratio.

a +

Fire H. Pea( and residal relati"e lateral dis*lacement of t%e *iers '%en t%e s*ecimen 'as s+jected to t%e far-

field rond motion ensem+le: a


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Fire L. Pea( *'ard and do'n'ard and residal relati"e dis*lacement of t%e s*erstrctre at mid-s*an '%ent%e s*ecimen 'as s+jected to t%e far-field rond motion ensem+le

Similarl#, for t%e s*erstrctre, t%e *ea( *'ard and do'n'ard dis*lacements at mid-

s*an increased 'it% t%e seismic intensit#4 %o'e"er, t%e residal deformations 'ere nelii+le, asdemonstrated in Fire L. T%e increasin seismic intensit# reslted in loss of "ertical contact+et'een t%e s*erstrctre and t%e ca* +eams. ;es*ite t%e fact t%at t%e im*act at reconnection

'as a "iolent *%enomenon, t%e moment strent% of t%e /S0 joint at mid-s*an controlled t%e

maimm seismic force a**lied to t%e s#stem.

ard le"el.

)n t%e trans"erse direction, t%e *ier dis*lacements decreased 'it% t%e time la as s%o'n

in Fire 17. T%is +e%a"ior is attri+ted to t%e as#nc%ronos inertial forces a**lied to t%es*ecimen. S*ecificall#, t%e time la redces t%e total inertial force a**lied to t%e s*ecimen at a

i"en time instant, since t%e inertial forces a**lied +# t%e s%a(e ta+les in t%e east and t%e 'est

side of t%e s*ecimen are not in *%ase. T%e same res*onse c%aracteristics 'ere o+ser"ed for t%es*erstrctre in t%e "ertical direction, al+eit, t%e corres*ondin redction 'as not as e"ident

see Fire 11. )n t%e lonitdinal direction, t%e res*onse of t%e s#stem 'as 8ite different,

*rimaril# de to t%e fact t%at relati"e dis*lacement +et'een t%e s%a(e ta+les in t%at direction

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cold enerate %i% +ase reactions e"en if t%e a**lied inertial forces to t%e s#stem remain small.

As a reslt of t%is +e%a"ior, t%e dis*lacement res*onse 'as almost insensiti"e to t%e time la.

a +

Fire I. Pea( and residal relati"e lateral dis*lacement of t%e *iers '%en t%e s*ecimen 'as s+jected to t%e far-field and near-falt rond motion ensem+les scaled to t%e ;< seismic %a>ard: a


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a +

Fire 17. Pea( and residal relati"e lateral dis*lacement of t%e *iers '%en t%e s*ecimen 'as s+jected to t%e far-

field rond motion ensem+le scaled to t%e =o' ;< seismic %a>ard: a ard.

3. CONCLUSIONS

)n t%is *a*er, t%e conce*t of %#+rid slidin-roc(in /S0 *ost-tensioned sementalmem+ers for +ride s#stems in seismic reions 'as *resented and e"alated e*erimentall#. T%e

/S0 mem+ers consist of /S0 joints co*led 'it% internal n+onded *ost-tensionin PT of

linear on nonlinear eometric la#ot alon t%e mem+er lent%. T'o distinct /S0 mem+er t#*es'ere considered4 t%ose 'it% sli*-dominant joints and linear PT eometr# a++re"iated as /S0-S; mem+ers, intended for s+strctres, and t%ose 'it% roc(in-dominant joints and non-linear

PT eometr# a++re"iated as /S0-0; mem+ers, intended for s*erstrctres.

T%e *ro*osed s#stem 'as e"alated t%ro% a series of s%a(e ta+le tests 'it% a lare-scale +ride s*ecimen incor*oratin a /S0-0; s*erstrctre and t'o sinle-colmn /S0-S;

*iers. T%e /S0-S; *iers e%i+ited s+stantial ener# dissi*ation, lare deformation ca*acit# and

moderate self-centerin ca*a+ilities. Small damae 'as o+ser"ed in t%e form of concrete

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crs%in at t%e +ottom and s*allin in t%e "icinit# of t%e lo'er /S0 joints, '%ile joint slidin

'as fond to +e a lo'-damae res*onse mode. T%e /S0-0; s*erstrctre e%i+ited lo'

ener# dissi*ation, %i% self-centerin and nelii+le damae. $ot% /S0 mem+er t#*esdemonstrated t%e a+ilit# to control of t%e a**lied seismic loadin +# modif#in t%eir stiffness

and strent%.

4. ACKNO5LEDGMENTS

T%e at%ors 'old li(e to ac(no'lede t%e Federal /i%'a# Administration of t%e !.S.;e*artment of Trans*ortation for *ro"idin fndin for t%is researc% t%ro% t%e

Mltidisci*linar# Center for

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132 Sideris Aref Filiatrault 7NSC Paper Final