Ista n b u l B rid g e C o n fe re n c e A u g u st 1 1-1 3, 2 0 1 4 Ista n b u l, Tu rke y S e is m ic P e rfo rm a n c e o f a n In n o v a tiv e Co n c re te F ille d S te e l Tu b u la r Tru s s B rid g e B ru n o B ris e g h e lla D ire c to r S IB E R C R e s e a rc h C e n te r S u sta in a b le a n d In n o v a tiv e B rid g e E n g in e e rin g R e s e a rc h Ce n te r F u z h o u U n iv e rs ity, F u z h o u - P R C A u th o rs : Y u f a n H u a n g, P h D St u d e n t, U ni v e rsità I U A V di V e n e zi a, V e n ic e, Ita ly B ru n o B ris e g h e lla, P ro fe s s o r, C o lle g e o f C iv il E n g in e e rin g, F u z h o u U n iv e rs ity, F u z h o u, C h in a To b ia Z o rd a n, S IB E R C R e s e a rc h C e n te r, F u z h o u U n iv e rs ity, F u z h o u, C h in a
CO N T E N T S 1. INTRODUCTION 2. SHAKING TABLE TESTS 3. THEORETICAL MODEL 4. THEORETICAL VERSUS EXPERIMENTAL RESULTS 5. INFLUENCE OF GROUND MOTIONS 6. CONCLUSIONS Co n te n ts
- C F S T S t r u c t u r e s C FS T is a s t e e l - c o n c r e t e c o m p o s i t e s t r u c t u r e in w h i c h a s t e e l t u b e is f i l l e d w i t h c o n c r e t e B o s i d e n g B r i d g e ( L = 5 3 0 m, w o r l d s r e c o r d ) 1. In tro d u c ti o n M i l l e n i u m T o w e r, Wie n ( H = 2 0 2 m, h i g h e s t b u i l d i n g in A u s t r i a )
- C F S T S t r u c t u r e s A d v a n ta g e o f co n c re te fille d - H ig h co n fin e m e n t o f ste e l tu b e s (CF S T ) th e co n c re te - E a rth q u a ke a n d F ire - D e la y o f th e ste e l R e s ista n c e lo c a l b u c k lin g - R a p id a n d e a sy - H ig h co m p re s s iv e a n d co n stru c tio n fle x u ra l stre n g th A p p lic a tio n o f tru s s ty p o lo - g S y a v in in b g rid s in g e co s n stru c tio n co sts Tr u s s t y p ol o g y is a d o p t fo r n e a rl y all t h e a rc h ri b s o f st e el a n d C F S T b ri d g e s. C o m p a r e d w ith st e el a rc h b ri d g e s, C F S T a rc h b r id g e s are c o n si d e r e d t o m o re e c o n o m ic a l. 1. In tro d u c ti o n C r o s s - s e c t i o n t y p e s o f C FS T a r c h r i b
- C F S T S t r u c t u r e s A ll t h e c r o s s-s e cti o n s o f t h e ri b s of t h e t o p 5 lo n g e st C F S T arc h b ri d g e s a r e tr u s s t y p e. C F S T tr u s s e s c a n b e also a p pli e d for t h e pill ar of d e c k arc h b ri d g e s ( a s i n M e n d o n g h e Ri v e r B ri d g e ) t o r e d u c e t h e s elf- w ei g h t o f sp a n d re l stru c tu re s. R a n k 1 2 3 4 5 N a m e B o s i d e n g B r i d g e W u s h a n B r i d g e Z h i j i n g h e B r i d g e L i a n c h e n g B r i d g e M a o c a o j i e B r i d g e S p a n ( m ) Y e a r 5 3 0 2 0 1 2 4 6 0 2 0 0 5 4 3 0 2 0 0 9 4 0 0 2 0 0 8 3 6 8 2 0 0 6 a) M en d on g h e B rid g e b ) B os id en g B rid g e c) W u s h an B rid g e 1. In tro d u c ti o n d ) Z h ijin g h e B rid g e e) L ian ch en g f ) M aocaojie B rid g e B rid g e
T - h G e a n o bje h a i c zi t B of r i d this g e res e a rc h is G a n h aizi Bri d g e, locat e d in a v e r y hi g h in t e n sit y s eis m i c re gi o n ( Sic h u a n Pr o vi n c e, C hin a ), o n e of t h e m o st u n u s u al vi a d u c t s t h at h a v e b e e n re c e n tl y b uilt. It h a s a t o tal le n gt h of 1 8 1 1 m, a n d t h e i n n o v a ti v e str u c t u r a l ty p ol o g y is c h a r a c t e rize d b y a d o p ti n g st e el t u b e s for n e a rl y e ntire str u c t u r e. D u e to t h e fav o r a ble d u c tility of C F S T m a t e rials a n d lig ht w eig h t tr u s s str u c t u r e, a g o o d e a r t h q u a k e b e h a v io r is e x p e c te d. 1. In tro d u c ti o n V i e w o f G a n h a izi B r i d g e
- G a n h a i zi B r i d g e T h e b ri d g e h a s a t otal le n g t h of 1 8 1 1 m, w it h lo n git u din al sl o p e 4 %, c o m p o s e d of t h r e e c o n ti n u o u s u nits, s e p a r a t e d b y 4 0 0 m m wi d t h jo in ts. T h e sp a n a rra n g e m e n t is : - T h e first u n its w ith 1 1 sp a n s (L to t = 5 6 3.3 m ): 4 0.7 m + 9 4 4.5 m + 4 0.7 m - T h e se c o n d u n its w ith 1 9 sp a n s (L to t = 1 0 4 4.7 0 m ): 4 5.1 m + 3 4 4.5 m + 1 1 6 2.5 m + 3 4 4.5 m + 4 5.1 m ; - T h e th ird u n its w ith 6 sp a n s (L to t = 2 6 8.2 m ): a) T h e f irs t u n it s c) T h e t h ird u n it s 4 5.1 m + 4 4 4.5 m + 4 5.1 m b ) T h e s econ d 1. In tro d u c ti o n u n it s E v a l u a t i o n la y o u t o f G a n h a izi B r i d g e ( Un i t : c m )
- G a n h a i zi B r i d g e T h e s u p e rstr u c t u r e is a s foll o w i n g : a) co n c r e t e d e c k, b) ste el tru s s w e b, c) C F S T b o tt o m c h o r d. T h e t y pic al cr o s s s e cti o n o f t h e tru s s gir d e r is 4 4 0 c m h ei g h t. T h e b o tt o m c h o r d t u b e s a r e C F S T w it h a di a m e t e r of 8 1 3 m m a n d t hic k n e s s fr o m 1 8 m m t o 3 2 m m, fille d w i t h C 6 0 c o n c r ete. T h e w e b st e el tu b e s h a v e a d ia m e te r o f 4 0 6 m m. 1. In tro d u c ti o n C FS T t r u s s e s g i r d e r ( Un i t : m m )
- G a n h a i zi B r i d g e T h re e ty p e s o f p ie rs h a v e b e e n u s e d : ( a) H < 2 5 m R ei nforc e d c o n c r e t e (R C ) d o u b l e col u m n pie rs. ( Pi er n u m b e r: 1, 1 0-1 3, 3 1-3 5 ) ( b) 2 5 m < H < 9 0 m C F S T tru s s p ie rs. It is g e n e r ally c o m p o s e d of fo u r C F S T co l u m n s c o n n e c te d t o g e t h e r b y st e el tr u s s t u b e s. 1. T h e C F S T c ol u m n s In tro d u c ti h a v e a di a m e t e r of o n 7 2 0 m m, wit h w a ll C FS T la t t i c e c o lu m n s ( Un i t : m m )
- G a n h a i zi B r i d g e (c) H > 9 0 m C F S T c o m p o site pi e r (t h e t alle st o n e is 1 0 7 m ). T h e tr u s s t u b e s a r e re p l a c e d w i t h 4 0 c m t hic k R C pl at e s a t t h e b o tt o m r e gi o n o f 3 0 m h e i g h t to i m p r o v e its ri gi dit y. T h e C F S T c o l u m n s h a v e a di 1. a m e t e r of 8 In 1 tro 3 m d m u c, ti a w all t o hic n k n e s s e s FC FS T c o m p o s i t e c o l u m n s ( Un i t : m m )
- C o n s t r u c t i o n ph a s e s o f G a n h a i zi B r i d g e 1225 1225 50 1075 200 1075 50 Web steel tubes (φ406) Steel fiber reinforced concrete deck 440 28 70 CFST bottom chord tubes (φ813) 1225 1. In tro d u c ti o n
- C o n s t r u c t i o n ph a s e s o f G a n h a i zi B r i d g e 1. In tro d u c ti o n C FS T p i e r s ( H m a x = 1 0 7 m )
- C o n s t r u c t i o n ph a s e s o f G a n h a i zi B r id g e 1. In t r o d u c t i on S e is m ic P e r fo r m a n c e o f a n In n o v a t iv e Co n c r e t e F i l l e d S t e e l T u b u l a r T r u s s B r i d g e
- S h a c k i n g Ta bl e Te s t s B a s e d o n t h e hig h pi e r z o n e of re al b rid g e a s p r o t o t y p e, a s h a k in g ta bl e test with t w o s p a n a n d t h r e e pie rs w a s d e si g n e d a n d p e rform e d i n F u z h o u U n i v e rsity. S u bj e c t e d t o t h e r e strictio n s of le n gt h a n d b e a rin g c a p a cit y of te st d e vic e, t h e g e o m e t r y s c al e rati o w a s c h o s e n a s 1:8. T h e s p e ci m e n h ei g ht w a s 1 3.9 m ( H r e al pi e r = 1 0 7 m ) w ith to ta l m a s s 2 0.9 t. E l e v a t i o n d r a w i n g o f t h e b r i d g e m o d e l ( u n i t : c m ) V i e w o f t h e S p e c i m e n 2. S h a c k in g Ta b le Te sts
- S h a c k i n g Ta bl e Te s t s - 3 0 a c c e le ro m e te rs, - 8 d is p la c e m e n t tra n s d u c e rs : - 6 0 stra in g a g e s, i n clu di n g lo n git u din al, 3(4) 1-1 1-6 1(2) 5(6) 2(4,6) 1(3,5) 2-1 2-6 3-1 3-6 tra n sv e rs e a n d v e rtic a l d ire c tio n s. 1-1(1-11) 1-2,1-3 (1-12,1-13) 1-2 1-7 7 8 2-1(2-11) 2-2,2-3 (2-12,2-13) 2-2 2-7 3-1(3-11) 3-2,3-3 (3-12,3-13) 3-2 3-7 1 11 2,3 12,13 Displacement transducer Transverse accelerometer 1-3 1-8 2-3 2-8 3-3 3-8 Longitudinal accelerometer Bidirectional strain gauge 1-4,1-5 (1-14,1-15) 1-4 1-9 2-4,2-5 (2-14,2-15) 2-4 2-9 3-4,3-5 (3-14,3-15) 3-4 3-9 4,5 Unidirectional strain gauge 14,15 1-8(1-18) 1-9(1-19) 1-6,1-7 (1-16,1-17) 1-10(1-20) 1-10 1-5 Shaking 2-8(2-18) 2-9(2-19) 2-6,2-7 (2-16,2-17) 2. S h a c ktable in g Ta b le Te sts 2-10(2-20) 2-10 2-5 Shaking table 3-8(3-18) 3-9(3-19) 3-6,3-7 (3-16,3-17) 3-10(3-20) 8,9,10 3-10 3-5 6,7 Shaking table 18,19,20 16,17 I n s t r u m e n t a t i o n a r r a n g e m e n t d e t a i l s
Q u a n tity D im e n s io n S c a lin g la w S c a le fa c to rs Lin e a r Le n g th [L ] 1 / 8 D is p la c e m e n t [L ] 1 / 6 4 E la stic m o d u lu s [E ] 1 S tra in -- 1 / 8 D e n s ity [ρ ] 1 A x ia l fo rc e [E L 2 ] 1 / 2 5 6 B e n d in g m o m e n t [E L 3 ] 1 / 2 0 4 8 A c c e le ra ti o n [E ρ -1 L -1 ] 1 F re q u e n c [E 0.5 ρ -0.5 L - y 1 8 ] p rot ot y p e T im e [E -0.5 ρ 0.5 L ] 1 / 8 a) S eis mic ex cit at ion ad op t ed f or S i m i l i t u d e r e l a t i o n o f q u a n t i t i e s 2. S h a c k in g Ta b le Te sts b ) S eis mic ex cit at ion ad op t ed f or t es t
- Th e o r e t i c a l m o d e l A t h r e e - dim e n si o n a l F E M w a s d e v el o p e d i n O p e n S e e s. T h e m a i n m e c h a nic al c o m p o n e n t s of pi ers, s u c h a s circ ul a r C F S T c olu m n s a n d sl a nt s u p p o r t s, w e r e m o d e l e d u si n g n o n lin e a r b e a m - c ol u m n el e m e n ts wit h d iscrete fib e r s e ctio n m o d el in O p e n S e e s, re m a i ni n g c o m p o n e n t s w e r e si m u l ate d u si n g elastic b e a m - co lu m n s e le m e n ts. F E M d im e n s io n : a ) 2 5 9 9 n o d e s; b ) 3 6 0 2 e le m e n ts a) G iu f f re- M en eg ot t o- Pin t o mod e 3. T h e o re tic a l M o d e l FE M o d e l b ) L ian g & F rag omen i mod el f or M a t e r i a l s c o n s t i t u t i v e m o d e l s
- M o d a l pa r a m e t e r s F r e q u e n ci e s are cl o s e to t h e o r e tic al fre q u e n c y rati o of 1 : 8, a n d m o d al sh a p e s are als o t h e s a m e, w h i c h d e m o n strat Meo dtahl e acc u r a c y of sim ilit u d e R e a l re lamtio o n s h ip. d e b rid g e (1 ) S h a p e (F E a n a ly s is ) S p e c i m e n (2 ) M o d a l S h a p e (2 )/ ( 1 ) 1 0.1 9 4 H z 1.4 5 H z 1 :7. 4 7 2 0.2 7 4 H z Fu n d a m e n t a l f r e q u e n c y c o m p a r i s o n b e t w e e n r e a l b r i d g e a n d s p e c i m e n O rd e r 1 4. R e s u2 lts Co m p a ris o n R e a l b rid g e (1 ) 0.1 9 4 H z 0.2 7 4 H z F u ll m a s s F E M (3 ) 0.5 2 6 H z 0.8 0 3 H z 2.1 0 H z (3 )/ (1 ) 1 :2.7 1 1 :2.9 3 T h e o re tic a l va lu e 1 :2.8 2 8 1 :2.8 2 8 1 :7. 6 6 E rro r 4.1 0 % Fu n d a m e n t a l f r e q u e n c y c o m p a r i s o n b e t w e e n r e a l b r i d g e a n d f u l l m a s s m o d e l 3.6 4 %
- D i s pl a c e m e n t s. To p o f t h e pi e r a) T ran s vers e ex cit at ion b ) L on g it u d in al ex cit at io 4. R e s u lts Co m p a ris o n C o m p a r i s o n o f d i s p l a c e m e n t t i m e h i s t o r i e s
- V e r t i c a l S t r a i n s C o m p a ris o n s o f v e rtic a l stra in s e n v e lo p e b e tw e e n e x p e rim e n ta l a n d th e o re tic a l re s u lts 4. R e s u lts Co m p a ris o n a) T ran s vers e ex cit at ion b ) L on g it u d in al ex cit at ion C o m p a r i s o n o f v e r t i c a l s t r a i n e n v e lo p e
- B i - d i r e c t i o n a l e x c i t a t i o n s a ) v e rtic al strai n s u n d e r tra n s v e rs e e xcitati o n s a r e la r g e r t h a n u n d e r l o n g it u di n al d ir e c ti o n at t h e s a m e int e n sit y le v el ( P G A = 0. 2 2 g ) a n d c o m p a r a bl e t o bid ire c tio n a l 80 e xc ita tio n s. b ) t h e s a70 Longitudinal extitation m e p h e n o m e n o n c o uld b e f o u n d f o r 60 Transverse extitation d is p la c e m e n t a m p lific a tio n. Vertical strain (µε) Displacement (mm) 4. R e s u lts Co m p a ris o n 50 40 30 20 10 0 10 8 6 4 2 0 Bi-directional extitations Slant support Top of RC web Bottom Position along the column Longitudinal disp. Longitudinal Bi-directional Transverse disp. Transverse Bi-directional 0.05 0.10 0.15 0.16 0.18 0.20 0.22 PGA (g) It s e e m s n o t t o b e n e c e s s a r y t o c o n si d e r t h e infl u e n c e of b i- dire ctio n al e x citati o n s fo r t his b rid g e.
- G r o u n d m o t i o n s i n f l u e n c e F oll o w i n g t h e D e si g n S p e cific ati o n for Hi g h w a y B ri d g e s (J a p a n R o a d A s s o ci atio n ), B ri d g e s with c o m p l e x d y n a m i c re s p o n s e s s h o ul d b e c h e c k e d for int e n si v e g r o u n d m o ti o n s ( e a rt h q u a k e s w i t h l o w p r o b a bility to o c c u r ) u si n g tw o ki n d s of gr o u n d m o tio n s : 3.0 a ) Ty p e 1. Pl at e b o u n d a r y ty p e o f T111 T112 e a rt 2.5 h q u a k e s w ith a m a g n it u d e T113 o f a ro u n d 8 ; T211 2.0 T212 b ) Ty p e 2. Inl a n d T213t y p e of 1.5 e a rt h q u a k e s w ith a m a g n it u d e o f 1.0aro u n d 7-7. 2 at v e r y s h o r t d ista n c e. Acceleration (g) 0.5 0.0 0.1 0.5 1 2 5 10 Acceleration(g) Acceleration(g) Acceleration(g) ion(g) Accelerati Acceleration(g) Acceleration(g) 1 0 T111(1978 Miyagi-Coast, LG), PGA=0.3251g -1 0 5 10 15 Time(s) 20 25 30 1 T112(1978 Miyagi-Coast, TR), PGA=0.3262g 0-1 0 5 10 15 Time(s) 20 25 30 1 T113(1993 Hokkaido-S/W_Coast, LG), PGA=0.3291g 0-1 0 5 10 15 20 25 30 35 40 Time(s) a) T y p e 1 Period (s) R e s p o n s e s p e c t r u m - T i m e h i s t o r i e s b ) T y p e 2 o f n a t u r a l r e c o r d s 5. In flu e n c e g ro u n d m o t. 1 0 T211(1995 Hyougoken_South, NS), PGA=-0.8281g -1 0 5 10 15 20 25 30 Time(s) 1 T212(1995 Hyougoken_South, EW), PGA=0.781g 0-1 0 5 10 15 20 25 30 Time(s) 1 0 T213(1995 Hyougoken_South, NS), PGA=0.7955g -1 0 5 10 15 20 25 30 Time(s)
- A. A c c e l e r a t i o n s T h e a c c el e rati o n e n v el o p e r e s ults s h o w t h at u n d e r lo n git u din al or tra n s v e rs e seis m i c e x citati o n s, a c c ele r ati o n d u e t o T y p e 2 g r o u n d m o ti o n s ar e signific a n tly l arger t h a n d u e t o T y p e 1 g r o u n d m o ti o n s. It m e a n s t h at w h e n s u bj e c t e d t o a str o n g g r o u n d m o ti o n s wit hi n s h o rt14 dist a n c e, t h e c ol u14m n c a n incre a s e t h e T111 T111 a c c el e ra ti o n r e s p o n st112 12 e 12 t h r o u g h r e m a T112 r k a ble T113 T113 o s cillati o n o n t h e l attic T211 e c ol u m n zo n e s, w h i c h T211 10 T212 10 re d u c e s a c c e le ra tio n o n th e d e c k. T212 Height (m) 8 6 T213 Height (m) 8 6 T213 4 2 4 2 0-15 -10-5 0 5 10 15 Acceleration (m/s 2 ) 0-15 -10-5 0 5 10 15 Acceleration (m/s 2 ) a) T ran s vers e d irect ion b ) L on g it u d in al d irect ion A c c e l e r a t i o n e n v e l o p e o f p i e r 5. In flu e n c e g ro u n d m o t.
- B. D i s pl a c e m e n t s - U n d e r l o n git u din al a n d tra n s v e rs e directi o n al e x citati o n s, dis pla c e m e n t s d u e t o Ty p e 2 gr o u n d m o ti o n s ar e s m all e r t h a n d u e t o Ty p e 1 gr o u n d m o tio n s. 0.15 - D i s pl 0.10 a ct111 e m e n t at t h elongitudinal t o p o f 0.05 T213 pi e r u n d e r T 1 1 1 is larg e r 0.00-0.05 th a n u n d e r T 2 1 3. Displacement (m) Displacement (m) -0.10-0.15 0.00 2.12 4.24 6.36 8.48 10.60 Time (s) a) L on g it u d in al d irect ion 0.15 0.10 0.05 0.00-0.05-0.10 T111 T213-0.15 0.00 2.12 4.24 6.36 8.48 10.60 Time (s) b ) T ran s vers e d irect ion 5. In flu e n c e g ro u n d m o t. Transverse Height (m) Height (m) 14 12 10 8 6 4 2 T111 T112 T113 T211 T212 T213 0-0.3-0.2-0.1 0.0 0.1 0.2 0.3 Displacement (m) 14 12 Pie r d i s p l a c e m e n t 10 8 6 4 2 a) T ran s vers e d irect ion T111 T112 T113 T211 T212 T213 0-0.3-0.2-0.1 0.0 0.1 0.2 0.3 Displacement (m) b ) L on g it u d in al d irect ion
- C. S t r a i n s a ) Tr a n s v e rs e dir e c ti o n. Strai n e n v el o p e val u e s re d u c e fro m b o tto m to u p. b ) L o n git u d in al dire cti o n. Strai n s at t h e p o siti o n o f sl a nt s u p p o rt a n d t o p o f R C w e b a r e l a rg e r t h a n o t h e r p o sitio n s. T h e sla nt s u p p o r t s h a r e s t h e i nt e r n al forc e, pr o t e c t t h e t o p c o n n e c tio n 14 14 b e tw e e n th e C F S T co lu m n a n d g ird e r. T111 T111 S u bj e12 c t e d t o stro n g T112 T112 g r o u 12 n d m o ti o n s of Ty p e 1 T113 T113 a n d Ty p e 2, th e p ie r ret211 m a in in e la stic ra n g e. T211 Height (m) 10 8 6 T212 T213 Height (m) 10 8 6 T212 T213 4 2 4 2 0-1 0 1 / sy ε ε T ran s vers e d irect ion N o r m a l ize d s t r a in e n v e l o p e a t t h e e x t r e m e e d g e o f s t e e l t u b e s 5. In flu e n c e g ro u n d m o t. ε / ε sy L on g it u d in al d irect ion 0-1 0 1
- C o n c l u s i o n s - T h r o u g h w hit e n ois e e xcitati o n, t h e i d e n tifi e d f u n d a m e n t al fre q u e n c y of str u c t u re is 1. 4 5 H z i n lo n git u din al dire c ti o n a n d 2. 1 0 H z in tra n s v e rs e directi o n. T h e fre q u e n c y ra ti o b e t w e e n p r o t o t y p e a n d m o d el is 1 : 7. 4 7 i n t h e first o r d e r a n d 1: 7.6 9 i n th e s e c o n d o r d e r, w h i c h are cl o s e d to t h e o r e tic al fre q u e n c y rati o o f 1: 8. A c c o r di n g t o t h e sim ilit u d e rel atio n s hi p, dis pl a c e m e n t of s p e ci m e n a g r e e s w ell wit h p ro to ty p e. - U n d e r bi dir e c tio n al excitati o n s, dis pl a c e m e n t a n d strain a r e n o t larg e r th a n s u bje c t e d t o o n e directi o n al s eis m i c i n p u t. H e n c e, it s e e m s n o t n e c e s s a r y t o c o n si d e r t h e infl u e n c e o f b id ire c tio n a l e xc ita tio n s. - T h e a c c u r a c y of F E M a p p r o a c h e s is v e rifi e d S e is m ic P e rfo rm a n c e o f a In n o v a tiv e 6. t hco r on uc glu hs io c onco ms npc rea te ris F ille od nsste eof l Tu bfu lan r dtru asms Berid ng te al fr e q u e n c y,
- C o n c l u s i o n s - I nfl u e n c e of gr o u n d m o ti o n s are i n v e stig a t e d w i t h t w o ty p e s of s eis m i c r e c o r d s, r e s ults sh o w t h at Ty p e 1 ( Pl ate b o u n d a r y t y p e o f e a rt h q u a k e s w i t h a m a g n it u d e of a r o u n d 8 ) e a rt h q u a k e s g e n e r at e larg e r re s p o n s e s t h a n Ty p e 2 (In l a n d t y p e of e art h q u a k e s w i t h a m a g nitu d e of a r o u n d 7-7. 2 at v e r y sh o rt d ista n c e ) e a rt h q u a k e s i n dis pl a c e m e n t a n d strai n of c ol u m n, w hil e t h e a c c el e rati o n s u bj e c te d t o Ty p e 2 e a rt h q u a k e s are sig nific a nt ly larg e r t h a n su b je c te d to Ty p e 1 e a rth q u a ke s. - S u bj e c t e d t o stro n g g r o u n d m o t i o n s of Ty p e 1 a n d Ty p e 2, t h e str u c t u r e r e m a ins i n e lastic ra n g e. 6. Co n c lu s io ncos n c re te F ille d S te e l Tu b u la r Tru s s B rid g e
6. Co n c lu s io ncos n c re te F ille d S te e l Tu b u la r Tru s s B rid g e