Phan tich on djnh cua cau thep lien h a p be tong cot thep trong qua trinh thi cong
Buckling analysis for steel-concrete composite girder bridge during construction stage
Ngay nhan bar 14/6/2016
Ngay sLfa bai: 03/8/2016 Nguyen Canh Tuan,
Ngay chap nhan dang' 15/8/2016 Bang Dang TungTOM TAT
Ket cuu dam thep lien hop be tong cot thep hien nav ttang diioc sii dung rat pho bien trong aic cong trinh cau tren the gi6i Lo?i kel c^au nay cung dang bat d.Ui duOc ling dung nhieu d Viet Njin, dac biet la d Ha N()i va thanh pho Ho Chi Minh de giai quycl van de giao ihong do thi- Tuy nhien, van de on dmh cii.i loai ket cau nay tioug qua Irinh thi cong vim chUa duac quan tam trong giai doan thiet ke Nghien cUu nay ^e tap trung phan tich on dmh cua he dam thep hen hop ban be tong cot thep trong qua trinh Lhi cong Mo hinh phan tich se dua iren bien phap thi cong nhip chinh dam thep ciia dU an cau LuOng Thilc thuoc tinh Ca Mau, 1 le dam thep se duOc phan tich va danh gia tt cac giai doan cau lap va do be long mat cau. Diia vao ket qua phan tich, bien phap thi cong se duoc danh gia \ j kiem ti a nham dam [iao linh an dinh cua he dam
I j k[w.^ dam thep-GTCT hen hop giai doan tin cim- m{a on dinli do u^n xoSn ddn^z thm.
ABSTRACT
have heeii commnnh used in bridge structuies on over the world. This type ot'structuri;
been being applied gradualh ui X'lelnam. opecialK in llano, and Ho Chi Mmh Cily lo solve uiban tiansportation probli,,..
However, stabilit) under construction oi this struclLiie has not been considered as a key point in design stage This study focuses in exuia-torsional analysis lor steel-concrete composite girdeib during constmction An analysis model is created based on 8 consliuctton method ol the main span of ( uong 1 hue steel bridge in Ca Mau province. The sled girder system is analj-zed and V ei liied dunng oi eel ion and deck slab pouring Trom results, the construction method is reviewed and examined to secure slabilitv ol iheairdei svslem
K o ^ o r d s Sleel-coiicrcie composite girder eoiisirueiioii stage. l!e\ui-al-toisional buckling.
TS. Nguyen Cinh TuJn
Giant; vien, Khoa KV Ihual Xa^ Dung, TrUOng Dai Moc Bach Khoa - Dai Hoc Qutic Gia Tp HCM TS Dang Dang Tiing
Chang vien, Khoa K\ Tliuai X.h Dung, "1 rUong Dai Hoc liaeh Khoa - Dai Hoc Qutic Gia Fp HC.M
iC^lTllSl 08.2016
i n n * ^- Gi«tW#u
" ' l y fl K S ^ t S m thep lien hop b§ tong c 6 t t h ^
•I hffn fl^ i ^ g diipc sQ dung rSt pho bien trong 1 cic cflng trinh c3u trin th4 gidi. Loai k f t cau nby 1 cung dang bSt dau duoc tJhg dung nhieu d Wet i N a m , d i c b i e t l a d H a N 6 i v a thanh phfi Ho Chi I Minh 64 giii quyet van de giao th6ng 36 thi . Ti^jdnuSn thiet k l danh cho loai ket dfcj n ^ da du'^c phft W&i v i cap n h | t lien tuc nham ho
^ tfg 1^ su tWet ke. Hien nay, b V i ^ Nam, trong I cflng tac thiet k l c6 t h i ap dung tieu chuan Pnriilt ^^^ ^ ^ " ^ ^ " ^ ^"-^JS [1] dus b*n phien
="WI1II1| ban tilu chuSn AASHTO IJIFD 1998 [2] ciia Hoa
" " " ' - - K?.Tuynhi&i, nfli dung hudng dan kiem tra 6n dinh trong qua trinh thi cflng chUa duoc c^p nhat day dii. Do dfl, v i & ki^m soat vin di 6n
* *nbseg|pnhi4utrdng5idanden nhifng riSiro 1 trong thift ki. 04 h?n c h i duett vin 34 niy t cflng tSc thiet k l c6 t h i tham khdo dc phien ' b i n mfli nhSt cCia AASHTO LWD [3], trong dfl,
^\kiM'^'^ ' ^ ' "^""9 ^^^ toan 9'ai Aoan thi cflng du»c
thep va h^ li^n ket ngang, Sau dfl, m6i mo dun se duac ISn Iuot cau I3p vao vi trf. Giai phap thi cflng cau I3p duoc mo ta trong Hinh 3.
vm
Hinh 1. M W Chung d u tuong Thyc
mim ^ * ' " ^ ^ tliuylt, cdc v&n 64 6n d\nh 6i i . « J '^^ ' " ^ ' " " * ' * * " 9 ' ' " ^ ^^"^ "6* dung kilm is™i?ltoSn dva t f l n cfc ti#u chuin t h i l t k l . Tuy .smdfliil nhiln, d l d i m bao thfim m0t mile d$ an t o i n , i l f l j t a f " * ^^^^ ^^ ' ' ' * " pfi^P thi cong can du^c
1 dSnh gid lai bSng mfl hinh phSn t i l hOu han isasfl Nghiin cOl. n i y si t^p tmng phSn tich 6n dinh ,seaiir» chju ufln-xoSn ciia h^ dSm th§p liln h^p M n
b l tflng cflt th^p trcmg qua trinh thi cflng. Mfl hinh ph3n tich se d^fi t r l n bi§n phdp thi cflng nh[p chfnh dSm th^p (35m) cOa du i n c l u Luong Thyt thufle tinh Ch IWau (Hinh 1). H0 I d i m t h l p se di/gc phan tIch va danh gia fl cSc ' glai do^n c l u l i p va do b l tflng mat c l u . Trong dfl, cic ilng xit ciia k i t cSu duOc mfl
• phflng theo thi/c t l nhu vSt li^u, mo hinh k i t cau. g l i i p h i p vi trinh t i / thi cong. K i t qua phan tich se l i m$t CO sfl b6 sung rat cfl gia tri d l d i n h gia l^i tinh 6n djnh cila h i d i m thep trong q u i trinh thi cflng. M^t c i t ngang k i t c l u nhip chfnh duoc t h i hi^n trong Hinh 2.
3 . B i ^ p M p t h i c 6 n g 2.1TiaaagtAilAphtddmtbip H$ d i m th6p sau khi duijic ehe tao hoan chlnh tgi n h i m i y s l dupc thdo rtt' v i vSn Chuyin d i n cflng tru&ng d l t r i l n khai thi cflng. B6n d i m t h l p s i duoc l i p r i p hoSn chlnh t h i n h hat mfl dun bao gflm hai d i m
Hinh 2. Mat d t ngang lift du nt^ difch
. 1 * - - ^ - ^
Hinh 3. Phuong lai w Up dJm nh^i diAih:
f a ) m 6 h i n h 1 : ( b ) m a h m h Z
2.2 TbI cdng ddbi tdng bdn mdt cdu Sau khi hai h^ d i m t h l p duoc cau l i p hoan chlnh v i o vl tri. He van khuon be tflng mat c l u 3uac l i p dat Giai p h i p 66 b l tflng m|t cau du kiln se duoc trien khai theo m^t trong hai phuong an nhu sau.
-Do be tflng t r l n t o i n tio mat cau.
- e d b l tong doan bien gan goi, do be tflng phan giUa nhip cfln lai sau khi be tong doan biln d^t 50% cudng dfl thiet k l .
Tli trpng tinh toan se bao gflm tai trong thi cflng va tai trgng ban t h i n k i t c l u Hai phuang an nay se duoc kiem tra va danh g i i v l van d l ky thuat va chi phi C3n dinh ciia ket cau se l i co sfl 3i chpn phuang an thi cong.
3. M6 hinh phUn tfeh mat 6n dinh do u6n-xoAn
3.1 Gial doan cdu lip hi ddm thip Cflng tac cau lap he dam t h l p duoc dUa tren hai phuang an da duoc trinh bay trong Hinh 3. Trong giai doan nay, tai trong tac dflng chi bao gom trong luong b i n than he k i t cau thep Bieu do mo men uon tuang Ung vdi timg phuong i n duac t h i hien tnong Hinh 4. Gia tri mo men uon Idn nhat khi d u l i p theo mfl hmh ^ ih 328kNm trong khi theo mo hinh 2 la
3.2 Giai doan ddb6 tdng mat cdu 32.1 Q6 be tflng t o i n mat eiu Mfl hinh t i i trong tie dflng va bieu dfl mfl men ufln duac mo t i trong Hinh 5. Tii trpng
tac dong bao gom: b i n t h i n h i ket cau t h l p , van khudn, va be tong chus dflng eiJng. G i i tri mo men udn Ifln n h l t do tdng tinh t i i t i c dgng trong giai doan nay l i 1698kNm,
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3
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->. » . . - n S B i " » ciriiaiiiifral>i<)li>in|
Hinh 4, Bifti e& mSmen uon theo dc phufflig an du ISp
Hinh S. Mohlnh (rfian KdiphutUigan d6 b* tfing toin nhip.
3.2.2 Dd be tdng theo p h i n doan Hinh 6 va Hinh 7 t h i hign mfl hinh tfnh t o i n v i bieu do mfl men udn cho gial flo^n dd be tflng doan b i l n g i n gfli va doan giua khi b l tflng b i n d hai d i u nhjp da dat 50% cudng do chiu n i n thiet k l . Mfl men udn Idn n h l t do tong tinh tai khi 36 b l tflng phan doan b i l n l i 1022kNm. IMd men udn trong trUdng h(?p dd b l tong phan doan giUa sau khi phan do?n b i l n dat cudng dfl y l u c l u tUOng t u nhu trudng hop dd b l tflng t o i n nhjp, Gia tri mfl men udn Ifln n h l t l i l698kNm.
:::S'
ifinh 15 Mft hinh phan tich giai doan d S M twig doan bien.
Hinh 7. Mo hinh phan (ich gisi do^n do'bS tong do?n gii(a, 4 . Mfl hinh v i p h i n tfeh b i n g phirong p h i p p h i n t ^ h f i t i han
4.1 Md Mnh phdn tdhdu han _ Mfl hinh c l u l i p v i ad b l tflng b i n m i t cau se duoc mo hinh bSng chuong trinh p h i n tieh p h i n ti7 hUu han ABAQUS [4]. Ddi vdi mo hinh c l u nang dam, h i hai dam t h l p cung vdi
cac dam ngang duac mo phong nhu trong Hinh 8 Oieu kien bien va tai trong dUOc mo phong tiieo Hinh 3 Hsi ui tn cau nang se duoc kiiao sat niiam danh gia va kiem tra phuang an lao lap dam nhusau
- Vl tn moc cau each dau dam mot doan 700mm
• Vl tn moc c^u cach dau dam mot doan 5300mm
Hinti 8 Mo hinli iip liai dam thep klii tau nang Giai doan do be tong mat cau cung duoc mo phong tuang tu Tuy nhien, trong giai doan nay, he dam thep va dam ngang da duac lap ghep hoan chinh Co iiai phuang an do be tdng mat cau duac xem xet nhu sau
- Do be tdng toan bd mat cau - Do be tdng pham vi doan gan gdi (cacii gdi 11 95m) Sau khi be tdng dat 50°o cuong do chiu nen thiet ke, tien hanti dd be tdng doan giua
Mo hi trong Hinh 9
^ pha j hUu han duoc r
Hiiili 5 Mo hioh lie dam thep khi do be long mat uu is) (iio lojn nhip vj ton bien (b) (ho doan giiia Tinii phi tuyen hrnh hoc, bien dang lan va pill tuyen vat lieu se duoc xem xet nham khao sat ung xij cua ket cau mot cach chmh xac va gan voi ttiuc te han Trong cac mo hinii riay, he dam thep se duac mo pisong bang cac piian tu tam 4 nut (S4R) Ban BTCT se duoc ino hinh bang cac phan tu khdi 8 nut iC3D8RI Su
Iren hop giu'a he dam thep va ban BTCT thong qua neo dmh dUac md hinh hoa bang dieu kien rang budc s.ii dung lien ket cUng (Tie) de dam bao su lien hap hoan toan cua ket cau
4.2 Md hinh vdt lieu
Ban BTCT sU dung be tong C30 theo tieu chuan ASTM co cUong do chiu nen 28 ngay la 31Mpa Tmh phi tuySn cua vat lieu be tong duoc md hinh vai duong cong Ung suat va bien dang tham khao theo nghien cUu d i xuat cua Hsu [5] va duoc the hien trong Hmh 5
Hinh 10 Ouan he ung sua! bien dang cua he long He dam thep sU dung thep chiu thcii tiet loai SMA490W-Mod theo tieu chuan Nhat Ban Vat lieu thep co giOi han chay tdi thieu la 345Mpa Trong nghien cUu nay, gidi han ben cua thep se khbng duoc xem xet Do do, vat lieu thep duoc xem nhu lam viec dan hdi va deo tuyet ddi Quan he ung suat va bien dang dac trung cho thep duac md ta trong Hmh 11
l^Fig blin . Hmh) 1 Quan he ung iusi bien dang cos ttiep 5. Ket q u i phan tich va dinh g i i 5. T Giai doan thi cong cdu Idp
Ketg
1 i2 Souniikeiguiphanlirhon i phan tich on dmh c dmh cua hai phuang
trong Hmh 12 True nen uon va true nSm ngang ngoai mat ph^ng Icm nhat Oia In mo men udn toi han cho md hmh 1 la 3508kNm trong khi mo men udn toi han cho mo hmh 2 la 4i04kNm Mo men deo ly thuyet an cau lap duoc the h
dung la gia tn momen la gia tn chuyen v
cua tiet dien dam thep chUa lien hop la 5036kNm Gia tri md men udn tdi han nay liin hen rat nhieu so voi gia tn mo men uon do ti<
trong ban than he dam thep khi cau ISp |j 382 1kNmva 173 6kNm lan luat cho mo hinh 1 va md hinh 2. Oieu nay cho thay ca hai mfi hinh cau lap deu dam bao an toan Tuy nhien ta cd the thay rang tiet dien dam thep khong dam bao dac chac de co the phat ttien hcjjn toan md men deo truoc khi mat dn dmh >;3y ta Ket qua chuyen vi va phan bo Ung suat klii mat dn dmh cua he dam thep dUoc the hien trong Hinh 13
5.2 Giai doan 36 be tong mdt eau Ket qua so sanh md men uon cac han ol:
he dam thep tuong Ung vdi cac phuong anflc be tong duoc th^ hien trong Hmh 14 Co the thay rang phuong an dd be tdng phan bien de gay mat dn dinh cho he dam thep han la phuang an do be tong toan nhip Trong truang hop phan doan bien duoc do be tong trudc, va cuong do chiu nen ciia ban be long duoc hmh thanh trong qua trinh ddng cung be tdng {50%fc va 100%fc), ket qua cho ttia'y khong CO su khac blel ve mo men udn cUc han giua hai truong hap nay
Hmh 14 So sanh ketqus phan wli on dmh khi do be tong Khi do be long toan nhip hay do be tint phan doan bien he dam thep ph^i chiu toan
Irong thi cdng Luc nay ti uc khang uon cung nhu la SL(C mat dn dmh cua dam thap han nhieu i<hi da lien hop Dua vao ke't qua piian the thay rang md men udn cue han cua 1 thep nho nha't la 38I0kNm tuong Ong -oong hop do be tdng phan doan biln va ia 4000kNm cho cac trddng lien hap
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OTh d j j u n f t i b i b i ^ d i n g ngoai mat phSng d i n a & i m l t kha nang tiep nh^n tai trpng. Su phan b6 lihg suat vi bien dang cua he d i r n
«hii 16. F)tdinilJi^iirit&d)iihliW«bel6ng«an giih.
Ti();,iihi6n, t i t c l cie phuong an thi cflng 36u &m bSp an t o i n . Mfl men udn Ifln n h l t do t i i tt^tw trong glai do?n thi cflng la 169BkNm M n g i 4 i 6 % so v « siJc khing m i t dn djnh cda h§ jIliT) tiilp. Do dfl, tui- theo d i l u k i ^ va k h i nangjtil cflrig cfl th4 i p dung cic phuang i n tni c$ng Wii dd b l tflng b i n m^t c l u .
B . l ^ l i i | n
Nghiin cUu n i y phan tfeh dn ^ n h ciia h i 1 d i m thep lien hop b i n b l tflng cdt thep trong ' q u i Wnh thi cfing. Hg d i m t h l p duac phin tich I vh d i n h gia flr cac giai dosin c l u l i p v i dd b l I tflng m^lelu. Dya v i o k i t q u i p h i n tfeh cd thg
! <Hnh g i i dui?csM6n dinh ciJah§ d i m thep dufli r tlcdflngcuatiltrpngtrongquitrinhthicdng.
Trong giai doan c l u l i p , phuong an cau Up mfl dun gom hai d i m t h l p dugc xem x l t Diifli t i c dung cua t i l trgng b i n than thi h i k^t dfu t h ^ v i n d i m bao dn djnh. Do dfl, cfl the ch9n diem mflc d u 6 vi trf dau dam hoic phfa.Jrong nhfp.
Trong gial do^n dd b l tflng m?t cau, phudng an dd b l tflng p h i n doan k i m dn dfnh hon so vdi phuong i n dd b l tflng toan nhip Phuang I n dd b l tflng p h i n doan dfli hfli p h i i cfl m ^ dUng thi cflng v i thdi gian chd b l tfing phit t r i l n cUdng dp. K i t q u i phin Uch cOng cho t h ^ cuflng dfl b l tflng trong p h i n do^n b i l n Ithflng c l i t h i l n sifc Wilng in ^ i h cOa h i d i m t h l p . Do dfl cfl thS lya chpn phuttig I n diS b l tflng t o i n nhip vdi g i i i p h i p d6 cudn chilu tir hai phia d i u nhip
TllU^THMinUO
1. aT(fl272^KeOKtliaidM^tlBai[gdu,«6 GUo Thong Van TJI.
1 « a m i two 1I99B), Bridge IteflnSpedfiatiafl, AAHTTO, Wflshhgton K, USA.
3. AASmO USD [20121, Bridge Eteign ^)edficatJQn, AAaHO. WashBigton DC USA.
4. ABAQUS Standard User's IManual Version 6.10 {2009|. Ifibbit, Karson and Sorensen I K .
5. Hsu ITC Mo YlfiOlO). Unified theory of conoete stiuctures(2nd£dieon),tohn Wlleyg, Sons, toc
