Anh hudng cua tham so ban san den do cuTng lien ket dam - cot trong ket cau lien hcfp thep - be tong
The influence of parameters reinforced concrete floor to stiffness connections in steel - concrete composite structures
Ngay nhan bai: 16/11/2014 Ngay s j ^ bai: 20/12/2014 Ngay chap nhan dang: 27/02/2015
T 6 M T A T :
Trong bai bao, tac gia gidi thi^u ve niit Hen ket dam - cot, cau kien ciam va san lien hi?p trong ket cau khung lien hdp thep - b^ tong, va trinh bay cdch xac dinh dp Cling ciia lifin k^t ditn - cpt dien hinh theo tieu chuan chau Au. Khao sat anh hildng cac tham sd ban sdn, gom: chi^u day ban san; dien tich tilt dien va mo dun dan h6i cua c6t th^p; khoSng each bo tri neo chot lien kft ban san v6i dam, nham Iam sang t6 dnh hiJdng cua cac tham so tr^n den dp cting cua mlt lien ket dam - c6t trong kit cau lifin hpp thep - bS tong.
ABSTRACT:
In this paper, the author introduces the beam - column connections, steel - concrete composite beams and floor element in the frame structures, and shows how to determine the stiffness connections ofthe typical beam - column according to European standards. Survey parameters affecting, including: slab thickness;
section area and modul elasticity of reinforcing bars; distance anchor, in order to clarify the influence of the parameters on the stiffness of the connections beam - column in composite steel - concrete structures.
Keywords: composite joints, connections, steel frames {niit dam - cot, khung thep, khung lifin htfp thep - be long),
PGS-TS. Nguyen Hong Stfn Dai hoc Kien tnic Ha N6i, Email: nguyenhongsondhkt^gmail.com Tel: 0913514110
Ths.GVC Tran Dai Quang Dai hpc Kien tnic Ha Ngi Email: trandaiquang7Q(Sgmail.com Tel: 0988106886
Nguyen Hong Stfn Tran Dai Quang
I.Oatvandl
Ket clu khung ch|u lUc, sCr dung clu ki(n lign hpp th^p - bi tong duoc sit dyng r6ng lai trong cic cong trinh xiy dung, v l gin dly l&n ket clu chiu lUc cho nhi nhieu ting. Cic d»
kien dim v l c6t dupc Ii6n ket v6i nhau th6iig qua niit li^n k^t, chiing g6m cic b$ phin nliif bu ldng, bin bich, th6p g6c gh^p, bin d6v.v„„
khi cbiu luc thi cic bo phin niy vl bin thSn tiel dien dam v l c6t tai d6 bj bien dang [1], Cac nghign ciiu cho thiy, ll^n k^t gilj^ dim v^c^
CO do ciJrng nhlt djnh, khdng phli ciing tuyjl dcii hole khdp \)/ tudng, chiing Inh hudng tin sii lim vigc cCia k^t cau khung. Cic nghign cilU ve Inh hudng cOa cic tham sfi v l hlnh thiic I ket den dp ciing cCia niit lien ket dim - c$t trung chO ygu cho khung thgp, cdn khunc hop thep - be tdng khi It. Thiy rSngI nghign ciiu Inh hudng cic tham sd liln k^t St do Cling niit lien ket, cdthethuc hign blng cat thf nghigm hoac tinh toin md phdng s6 blng phan mem chuyen dung, cic nghign cilu nij chiem thdj gian tinh toin v l chl phi khi ldo Tuy nhign, mdt cich don giin han, bSng vi^csO dung phuong phip t6 hpp dp ciing thinh pMn
[component method), di duac di c|p trong tUuchuin thiet ke ket clu thip v l ket clu lign h^
thgp - bg tdng cCia chiu Au (EC3 v l EC4) [5,71 de ti'nh toin dp ciing cOa lien k^t thdng q u ^ Cling thinh phSn, gdm dd cting cOa d c » phan clu kien cdt, dim, chi tiet lien ket vl b^
sin bg tong c6t thgp. Do viy, ndi dung bai bio
niy se sCr dung tieu chuan chiu Au d^ khio salInh hudng cCia tham so bin sin den do c*!!
cCia lien ket dam - cot trong ket clu khungP hpp thep - be tdng, nhlm dinh gii miifc*
anh hudng cila tham sd nay den d6 ciing w kien nghj cic nh& chuygn mdn trong vigcflfe chinh d6 Cling ciia nut lign ket dim - cdt bing each dilu chlnh tham so ban san.
2. Tinh fld ciJng cda lign ket dam - cot tron) k£t cJu li§n hcrp thgp - bg t6ng
2.1. Ndt liin kit ddm ->( Hen hap
Do lign kgt dim - cot trong'ket clu khungthgp ndi Chung vk ket clu khung hgn hop iW - bg tdng ndi rieng, chung rat da dang,*
adBRiniBV 7.2015
• phan loai phu thudc vho nhieu tigu chl, cd t h e
"dua v i o d p ciifng cOa lien ket h o l e theo hinh thiJrc, vi tri lign ket h o l e loai ket c l u khung chiu lire v.v. .
Nhu 6 Hlnh 1, the hien m d t sd kieu lign ket tjdlm - edt ph6 bien trong kgt c l u khung lien hpp thgp - be t o n g , kieu SLT dung mat bich v l bu Idng (Hlnh l a ) ; kl^u h l n true tiep d i m vdi cdt (Hlnh l b ) ; kieu sCr dung thep gdc v l bu Idng
^(Hlnh 1 c); ki^u sCt d u n g mat bich v l bu long, ket J,hpp gdi d d (Hlnh I d ) .
j , l j U . D4m vi sdn Kin hep
• - D i m lign hop, g d m c i c bd p h i n : dam L i h l p (thgp hlnh h o l e thep to hpp); s i n be tdng
^z6t thgp (ed t i m t d n hoac khong tam tdn) v l :ae lien kgt d i m vdi s i n bg t o n g (chdt neo hoae , jhgp gdc), cau tao d i m lien h f l p duoc minh hpa
? j ^ l l H l n h l [ l , 7 ] .
- Sin lign hop, g d m c i c b d p h i n : t i m t o n linh d | p ngudi dat 6 phia dudi; t i m s i n be dng cdt thep; v l c l e lien kgt t i m t d n vdi san bg ' dng (ehdt neo).
" _ Ygu e l u cau tao chi t i l t c l e bo phSn s i n
•^gn hpp [1,7]:
f ' - Chigu d l y s i n , chieu d l y h = (80-400)mm, ,''':higu d l y ciia rigng phan bg tdng n i m tren '!t6ng tdn, ha > 4 0 m m ;
''"' - T i m tdn hinh dap ngudi, chieu d l y t i i ''%,75-l,S)mm, de chong an m d n , eae t i m t d n 5jU0c ma kgm 6 hai m a t gidi han dan hoi cua
^ ' I t ligu thgp t d n k h o i n g 300 N / m m ^
"^ - Neo lien ket, t h u d n g sCt d u n g c i c neo '"'rhdt, c6 tiet dign trdn cd m u . Chieu eao cua 'f:hdt hen £ 3d, trong dd d la d u d n g kfnh than
^Shdt. P h i n m u cd d u d n g kinh hcd > l,5d, v l
"Jihigu cao m u hn > 0,4d, k h o i n g c i c h giiia c i c ' ;h6t theo phuong vudng gdc vdi luc c i t a^ >
•^id, k h o i n g c i c h theo phuong cda lUc c i t a« >
'^ 1,56 vdi b i n s i n d | c v l ai:$ s 4d dfii vdi c i c ban
^ n khae K h o i n g dch ldn n h l t cSc neo chdt an
" = 6h h o l e ao < 800mm.
- C6t t h g p h o l e ludi thgp, dUcrc bo trf trong )h^m vl chigu d l y l i m vigc (h^) cOa b i n s i n be
t d n g . K h o i n g each giO'a c l e thanh t h e p a = min{2h, 3S0mm) v l ham lUong thgp theo ca phuong khong dUOc nhd hon SOmm'/mgt dai.
M d d u n d i n hdi cda vat lieu thgp trong k h o i n g El = (190 - 200)kN/mm'. De d o n g i i n t i n h t o i n trong kgt cau hgn hpp cho p h i p l l y g i i tri Ei la gia trj cua Ei = 210kN/mm^ cda t h g p kgt c^u.
Tuy nhign, d o d i e diem lam viec tai dau dam, va day eung la nut lien ket d i m - cdt, m d men udn trong dam gay keo cho b i n s i n , va t h u d n g g i i thiet tdn t h e p khdng t i n h t o i n tham gla chju liic ma thay vSo d o la cac thgp san de chiu lUc kgo. Chinh vl vay, eae t h a m sd eiia ban san I n h hudng den sU l i m vigc ciJa ket cau, bao g d m : chigu day p h i n bg tdng (ho); dien tich cdt thgp chiu keo (AO. m d d u n d i n hoi cdt thep (E,) v l khoang eieh c i c neo chm c i t (a).
2.3. Xdc dinh do cutig cua liin kit dam - cot lien hap [3,7,9}
a) Xac d m h d d ciing t h i n h phan cOa lign kgt dam - cpt khdng lign hop
Trudng hpp nut lien ket dam - edt khdng lien hop (trong khung thgp t h d n g t h u d n g khdng ed ket e l u kien hop), viec x i c dmh c l e dd Cling thanh phan n h i ^ d o ciing ciia b i n bung cdt chiu nen (Kc«), dp citng cua b i n bung cdt ehiu kgo (Kc^), dp ciing cua b i n c i n h cdt ehiu uon [Kn,], do cdng cua m l t bich chiu udn (Ktpb), dd Cling eiia buldng ehiu k i o (Koi), do Cling cda c i n h t h g p gdc trgn chju udn (Kub), duoc xac djnh theo tieu chuan thiet ke ket e l u t h e p cda chau Au, Eurocode 3 {EC3). V i n de nay d l dUdc trinh b i y trong bai b i o [2]
b) X i e dinh d d cOng thanh phan cOa ndt l i l n ket dam - edt lien hpp
Khi ed n i i t lien ket cd s i n lien hpp thep - be tdng, ngoai c l e d d cdng t h i n h phan da neu d trgn, luc n i y cd t h e m gia tri dd ciing t h i n h phan cda s i n lign hpp (Kiongir) v l g i i t n d o ciing cda bpng cpt chiu c i t (Kcws), g i i trj n i y thay doi d o c i n h tay don cda nut lign kgl thay doi
- D p Cling (Kiong«) cda thgp chiu kgo trong s i n lien hpp:
* Khi chi xgt den bien dang cda thep doe chju kgo trong b i n s i n l i l n hpp, d d ciing Kj^rg.v
= KL< dupc x i c dinh n h u sau:
Kij - hg sd d d Cling cua thgp dpc trong b i n s i n chiu keo, cu t h i n h u sau:
+ vdi d i m chi cd m d t phia cua c d t x i c dinh theo cdng thiic.
K^=AJ{3,6hc) (1) +• vdl dam cd hai phia ciia c d t v l momen udn hai phia b l n g nhau {Man = Mua.,). xac dinh theo cong thiic:
K., = A>/(0,5hJ (2) + vdi d i m d hai phia eua c p t mdmen udn d phia ed gia tri Idn h o n ( c h l n g han phia ed Madi khi MBOI < Muai), x l c dinh theo cdng thilc:
' ' • • - h , [ ( 1 + P ) / 2 + K , ] E . vdi:
K j = p ( 4 , 3 p = - 8 , 9 p + 7,2) (3) P - he sd, xac d m h n h u sau;
+ vdi ndt bign, cd d i m d m d t phia cua cot:
+ vdi niit giua, cd dam d hai phia cda c d t t l i trong va mdmen ddi xUtig: p=0;
+ vdl nut gida, ed d a m d hai phia cua c d t t l i trong khdng ddi xirng:
d phia t l i trpng ldn: p = 1 ; d phia t i l trpng nhd. p!=0 v l Ka = 0;
Al - dien tfch tiet dien thgp chiu kgo trong b i n san, x l c dinh theo edng thilc:
A, = M.deff(b,ffi,-b<) (4) theo yeu eau ve cau tao A ^ " ^ A^ < A ^ ° " , vdi:
A7'" = 0,004d^ { b ^ t, - b , ) , v l . „ « _ 1 . 1 ( 0 . 8 5 f ^ , ; y , ) b , d ^
''' = wj^) • *"
d d a y
be - chigu rdng net dien c i n h c p t befTb - chigu rpng hieu q u i b i n san, x l c d m h theo cong thiic:
brfb = 3hb (6) deff - chieu d l y higu q u i cua b i n s i n , deo =
h „ ;
ftk - cUdng d o t i l u ehuan cua thep ehiu keo trong bgtdng;
fcL - cudng dd tieu chuan cda v i t lieu bgtdng;
Yci Y) - he sd tin cay cda vat ligu bgtdng vS thep:
H - h i m lUOng cot thep trong ban s i n , x l c dinh theo cdng thilc:
(7) - b , ) d ^ Dieu kien, 0,3% £ n < 0,9%
- D p cdng (Kkm^) cda thep dpc chiu keo trong s i n lign hop khi xgt den ca bien dang cua chdt neo lien k e t
Ko„^. = K^,Ku,p (8) Irong d d :
Kiip - he sd giam, x l c dinh theo edng thilc:
1 (9)
vdl:
Ei - mddun d i n hdi eda vat ligu t h i p dpc ciia b i n san;
Kit - he sd d o cdng cua c i c neo ehiu c i t x l c dmh theo cdng thdc:
K „ = - (10)
d i - k h o i n g each tCr true trung hda cua d i m thgp den trong tam tiet dien thgp chju kgo trong ban san, x l c dinh theo cdng thilc
d , = 0,5hb-Hha + h p , - a « (11) hh - canh tay ddn eda thgp dpc trong b i n san lien hpp ddi vdi tam quay, x l c dinh theo cdng thdc:
hk = hb - 0,5ttb + ho + hp> - a „ (12) d d l y :
hb - chigu cao tiet dien dam;
at! - khoang c i c h t i l trong tam den tigt dien cdt thep san den mep tren ban s i n .
hn - chieu d l y l i m v i l e cda b i n san bgtdng, ha = d ^
hp, - chieu cao sdng t d n ,
^ • he sd, xgc dinh theo cdng thiic:
^ =
djE.A, (13)- he sd, x l c djnh theo edng thiic:
|(1 + 4 } N k , , L , „ , d f
L^fib - chieu d l i hdu hieu eda b i n san, xae dmh theo cdng thdc:
Uffb = 4hb (IS) N - so Iuang neo ehju c3t tren chigu
rdng hUu hieu cda b i n san, x^c dinh theo cdng thiic:
N = (Letfi/khoing each neo +1) (16) la - mdmen q u i n tfnh bae II cua tiet dign dam thgp;
k«: - dd cUng ciia mdt neo chiu e l t - Dp Cling cda b i n b u n g edt chju c i t (Kci) khi cd sU lam vigc cda san lign h o p : Khi cd su lam viec cCia lign h o p , liic nay c i n h tay d d n cda m d i ndi thay doi vi v i y d d Cling eua b i n bung edt chiu c i t (K,„,), xgc d i n h theo cdng thde;
= 0.3
P h ^ (17)
c) Xlc djnh dp Cling cda nut lign ket d i m - cdt lign hpp
Vdi nut lien kgt dam edt sii dung m5t bich - buldng v l ndt lign ket dam cdt sir dung thgp gdc - buldng, ldc n i y Ke, la dp cdng tuang dudng cda thgp doe trong b i n s i n v l cua c i c hSng buldng do! vdi tSm quay, xae dinh theo edng thdc:
K « , „ g „ h , + ^ K h
b) 0 6 Cling cda niit hgn ket dam - edt
1 1 , 1
Buac 1 Thong so dau vao kich ihucrc col rhip. h , l^b^.t kich thudc d ^ kicb ibatK san lie kikh thuoc nial b kich thuoc bul6n duong han a^, a vacai dac inriig
b>>n,>«.Iib.a nhop h ch b ,,i„ h^.
J.R.W uo VJI heu
r,
..fc,
Biioc Xac dmii ihong so i la.) chieu dav lam lb) dien lich c61ih
<c) mo dun dan ho
<d) khoang cach n
!'^".'."... h
•psan A, cuaUiep E.
0 chSI•a
c) tliep goc ffen chiu uon K^, EC^
d) thep eoe hung dam chiu uon l t „ , c l bu long chtu keo K^
f) hdng bu Jong bu long K,. K , , K i g) byng cot chiu nen K , ^ h) ihep chiu keo Irong s i n K|„^ „
I Buoc 5 Tinh dp cimg i
:JZ
•.nm Buoe 6 Danh gia anh huong cua thorn s6:
in
(a) chieu day lam v i f c eua san h , (b) di?n tich cdt thep s i n , A , (c) mo dun dan hoi cua (hip E, (d) khoang each neo choi a den dg cung CL
H ^ = ^ — (211
C l e k y h i g u khac dUOe g i l i t h f c h va xac djnh n h u d t a l l i g u [ 3 ]
2,4. Quy trinh tinh todn Ho cOng cda liin k4t ddm-cot liin http
Quy trinh tinh t o i n d d eilng mit lien k^t dam edt sil dung mat bich - buldng, dUoc mmh hoa trong Hinh 2.
3. K h i o s i t I n h hUdng cic tham so b i n sin den d o cdng lien ket dam - cot 3.1. Thdng sdtinh todn vdyiu cdu khdosdt ' a) Thdng so t i n h toan
Niit l i l n ket dam - edt trong ket eau lign hop thep - bg t d n g , sCf dung mat bfch \ik buldng (nhu Hlnh 3), eae thdng s6 ve vat ligu vJ hinh hpe n h u sau:
Hinh 2 Quy trlnlitirh toan
tfong dd:
hsa- canh tay ddn tUOng duong ddi vdi t i m quay, xac dinh theo eic trudng hop sau'
+ Vdi n d t lien ket dam cdt sCfdung han true tiep, xae dmh theo edng thdc;
trong do
h, - eanh tay ddn ngau luc ddi vdi tam quay.
+ Vol nut lien ket d i m cdt sd dung m l t bich buldng va niit lign kgt dam cdt sd dung thep gdc - buldng, liie nay heo la c i n h tay don tUong duong cua thep doc trong b i n san va cda c i c hang buldng ddi vdi tam quay, xac dmh theo cdng t h i l c
TOI 3
i L - u
Hinh 3. Ndt lign ket dam - cdt sil dung m | t bfch va buldng Vat ligu thgp dam va cot cd mddun d i n hdi, E, = 210.10'N/mm' Vat ligu t h g p chju kgo trong ban s i n cd cudng d d chiu kgo tieu ehuan, U = 4 6 0 N / m m ' v l mddun dan hoi, t = 210.10' N/mm. Cudng d d chju ngn tigu c h u i n ciia bgtdng trong b i n s i n , fck, = 20N/mm'. He s6 tin cay cda vat ligu betdng va ciia thgp l l n iuptla Y. = 1,5;y,= 1,15.
* Dam cd kich thudc hlnh hoc:
Chigu cao tiet dien d i m , hh = 350 mm Chigu d l y b i n bung dam, twb = 6 m m Chigu rdng ban c i n h dam, bn, = 170 mm • Chieu d l y b i n canh d i m , tib = 8 mm Chieu eao dUcmg han b i n canh vdi bung dam, aib = 6 m m
* S i n Irgn hpp: u C h l e u d l y l a m v i g c e u a b l n s l n , h o = 8 0 m m •';
Chieu day higu q u i eda b i n san, drf=80mm •.
Dign tfch cdt thep san, A, = 402 mm^
K h o i n g eieh t d cot thgp chju keo san d^n mgp san, ao = 40mm
Chigu cao sdng tdn, hp, = SOmm Neo chiu c i t lien ket vdi dam thep, loai neo chdt voi duong kinh dau neo la 19mm, dO cdng, k« = 100.^0=N/mm^ k h o i n g each c i c neo e h o t t r o n g s a n , a = 100mm
* Cdt cd kfch thudc hlnh hinh h o c
8 6 B W i 1 ' 1 ^ i K l l 7 . 2 0 1 5
- Khi cd b i n san lign hpp, d d eilng cda ndt lign ket d i m cdt sd d u n g mat bich - buldng tang (22,00-39,80)%. NhU vay, b i n s i n lien hop d l l i m tang dp cdng cua ndt lign kgt dam cdt.
- Trong cac trudng hpp khao sat d trgn, trudng hop t i n g dien tich cot chju keo trong s i n lien hop I I trUcmg hop l i m tang dd cilng cua niit lien ket dam cdt d i n g ke. Tiep dd la trUcmg hpp tang chieu day lam vigc cda san lign hop, hai trudng hpp con lai gom tang mddun d i n hdi cua cot thep chtu keo v l k h o i n g c i c h eic neo trong s i n lign hpp da lam tang dd cdng cda niit lign kgt nhung khdng d i n g ke.
Vi t h ^ , de t i n g d d ciing eua ndt lign ket d i m cot trong kgt cau khung lign hpp thgp - be tdng, t i c g i i kign nghi can quan t i m den I n h hudng cua yeu to dign tich c6t thep chiu keo trong s i n v l chieu day cua s i n lign hop.
4. Ket luan
- Tren day, t i c g i i d l p h i n tich co sd lu^
chpn tham sd cda b i n san va xay dung quy trinh t i n h toan khao s i t anh hUdng cle tham so d d dgn dp citng cda ndt lien kgt dam - cdt trong ket cau khung lien hop t h e p - be t d n g .
- Qua viec k h i o sat cho thay, b i n san cung cd anh hudng den d d eutig cua nut l i l n ket dam - cpt, v l t h u d n g lam tang t h g m gia t n do cdng so vdi khdng xet den I n h hUdng eua ban s i n . Viec tang d p cdng cda nut lign ket dam - cdt, do anh hudng cda t h e p chiu kgo la chinh va se higu q u i khi tang dien tich cdt thep quanh ndt lign k e t
Tai lieu tham khio
t Pham Van H6i, (2006}, Ket cdu hin hop thip - bUong, Nha xult bin Khoa hoc va Ky thuat, HI Noi
2. Nguyen Hdng Son (2013). 'Mot cadi xac ^nh cac dac trung co hoc ctia nut lien ket dam - cot trong ket cau khung thep', Tap chiXay dung, so 4/2013, trang 70-74
3 Nguyin H6ng Sdn (2013), "Xac dinh d o cung cua lien ket dam - c o t trong ket cau khung li§n hop thep - b e t o n g ' . T a p c h i X a y diflig, sfi 5/2013, trang 7 1 - 7 5 .
4 Le Hong Kien (2014), Oanh gia anh hUong san lien hop thep - be tong den do mem cua nut khung, tuan van Thac sl ky thuat, Trudng Dai hoc Kien t n k Ha Noi.
5 CEN (2004): Eurocode 3 (1992), Design of Steel StniOures-Part l-8-DesignofJomls. ENV 1993-1-1:1992.
6. AI5C (2003), Partially Restrained Composite Connections, Steel Design Guide Series.
7 CEN (2004)'Eurocode 4 (1992), Devgn of Composite Sted and Concrete Structures-Part I-1-General Rules and Rules for Buildings, ENV 1994-1-1:1992,
8 Fadla C, Piluso V „ Rizzano G. (2000), Structural Steel Semi- Rigid Connections Theory, Design and Software. CRC Press, Ekica Raton, FL
9, Structural Steelwork Eutocodes Development of A Trans- Naiional Approach, SSEDTA (2001), 'lecture 9-Composite Join^
7.2015BilS1i:[tBiT, ]
