DIEN DAN KHOA HOC C O N G NGHE
THiif Dl/ BAO BANG PHl/CfNG PHAP SO SANH CACH IJNG XUf MONG B^ - COC TRUNG TAM TAI CHINH THE GlOfI T H M HAI
Tren cfl sfi kinh nghiem thiet ke Too nhd Kim Mgu cao 420,5 m (Jinmao ThJfing Hdi), Tdc gid dJ bdo thJ mot so tieu chi nha khd ndng mang tdi ban ddu cud coc vd siJc chju tdi cua coc tdng theo thdi gian, phdn chia tdi trpng cho cpc vd cho bdn mong be , chpn chieu ddy bdn ddy be, diJ bdo dp lun mdng be - cpc vd thiet ke ly thuyet doi vdi ket cdu mdng Too Nhd Trung tdm Tdi chinh The gidi Thapng Hdi coo 492,0 m. Sou cung Id mpt vdi nhgn xet, ddnh gid ve ly thuyet dp dung thac nghiem hai tda nhd tren de thiet ke mdng cpc sieu ddi cho cdc tod nhd sieu cao tdng dThapng Hdi.
JIAN GONG ; XIHONG ZHAO; BAOLIANG ZHANG (Shanghai no 1 const. Limited Corp.) Ngadi dich PGS. TS. Nguyin Bdo Huan CDC
Trung tam Thifdng Hai
1. M d DAU
Trung tam Tki chinh The' gidi Thifdng ffii, (SWFC) cao 492m (so vdi ban dau cao 460m) dufng canh Kim Mau(JB) hien hijfu 88 tang cao 420,6m la kie'n tnic cao nha't ThUdng Hai va cao thuf hai The' gidi (xem anhl) do Mori Building Co. Tokyo dau tif gia 1,1 ty USD va van phong K F C (My) thie't ke' dien tich
377300m\ toa lac khu pho' Dong nhin xuong song Hoang Phd' tai Luc Gia Chily. Toa Nha bao gom mpt toa thap chlnh co 4 tang ham va nha quay 5 tang cao vdi 3 tang ham. Toa thap cao 101 tang, kien tnic hinh lang tru 4 canh (58m) mot Id thung dUdc khoet tron tren dinh mai la dai quan sat cdng cong, ke't ca'u tai 4 gdc cd 4 cot c3 ldn bao vat lieu
tong hdp,va tang cao hdn cd 6 cdt tao mat b^ng 6 canh, vdi he ke't ca'u thanh chong xien c3 ldn, gian cufng, cot khung - ong loi be tong cot thep to hdp thep hinh.
Ngay 30/8/2008 toa nha dUa vao sijf dung, khai thac sieu thi ban le, v5n phong, khach san 5 sao cao cap nhat, cufa hang Sn Trung Quoc d tang 93, lau ngam canh d tang 100.
Bang 1: So heu cd ban ve chieu cao so tang, kich thUdc tai xuong mong be- cpc cua hai Toa Nha
Ten Cong
trinh T6a n h i JINMAO Tda n h i SWFC
Chieu cao toi th£p
( m ) ^ (n) So tang
420.5 88 492.0
101
Be d i y mdng bfe/
Chieu sau Mdng be (m
4.0 19.65
4,5 18,45
SolUdng coc/
Chieu dai coc (m)
429 83 1177
79
Tai trong t.b tren coc(KN)
Kha nang chiu tii tb ciia coc (KN)
7000 7500 3221 4300
Tong tai cong trinh
Ap life nifdc day ndi (kN) 3 000 000
0 4 400 000
608.200
Di§n tich mdng (m^) Ap life mdng (kN/ m^)
3519 852.5 6200 709,7
NGl/dl XAY DONG S6 THANG 11 • 2009
THlJfD^r BAG B A N G PHl/OfNG PHAP SO SANH..
Dtfa Uen cd sd kinh nghiem da thie't ke t6a nhk Kim Mau, bai viet suf dung phifdng phap so sinh de dif bao each utog xuf cua mdng bd-cpc doi vdi tda nhk Tnmg tam Tai chmh The gidi Thtfdng Hai sieu cao tang (bai\ be belong d toa thap chinh 30 OOOm') .
2. DIEU KIEN DIA CHAT CONG TRINH CUA HAI TOA NHA.
TrUdc tien hay so sanh dieu kien dia chat cong uinh cua hai toa nha nay nhU sau:
2.1. Dieu ki^n dia chdt cong trinh ddi vdi tim nha Jin Mao Dac trUng cd hoc, vat ly cua dia chai't cong Uinh la dat mem yeu nhieu ldp ( set - cat) va cao dp mtfc nUdc ngam trung binh dUdi mat dat la 0,50m. (co the tham khao Bang 2 tai heu goe)
2.2 Dieu ki^n dja chd't cong trinh ddi vdi toa nhd SWFC Dac trUng cd hpc, vat ly cua dia chat cong trinh va mtfc nUdc ngam trung binh dUdi mat dat giu'a hai toa nha CO nhieu diem tUdng tU, trif ldp da't so 8 co d cong trinh SWFC. (co the tham khao Bang 3 tai heu goe).
Mdi UUdng hdp cung cap mot dieu kien dia chat de du bao each u'ng xuf cua mdng be-coc.
3. KHA NANG MANG TAI CUA CQC DOI VOfI HAI TOA NHA
3.1. Cpc thi nghiem chd't tdi cda toa nhd Kim Mdu (JINMAO)
De cd dUde so heu tin eay ve kha nang mang tai coc suf dung cho thiet ke' mong be- coc, tnfdc het hay bat dau thifc hien thi nghiem chat tai 6 cpc ong thep dudng kinh D 914mm tai cong UUdng.Tuf phan tich hon hdp so' lieu dtfdc kha nang mang tai cho phep ciia cpc ong thep ddn bing 7500kN.
ranuM
Hinh 1 - Mat bang bd tri mong cgc tda thdp vd nha quay
Anh 1: Tda nhd Trung tdm Tai chinh The gidi Thugng Hdi SWFC
3.2. Coc chat tdi thi nghiem cda toa nhd Trung tdm Tdi chinh The gidi ThiAfng Hdi SWFC
De thie't ke mdng be-coc, tai cong UUdng ngUdi ta tie'n hanh chat tai thi nghiem tham do 15 coc dng thep dudng kinh D 700 (H3 - H9 sau 80m; HI sau 79m;
H2, L2 - L4 sau 60m; L l , L5, L6 sau 48m). Tif sdheu ket qua thi nghiem 15 coc nhan dUdc siJc chiu tai gidi han la 1 lOOOkN tUdng ufng cpc dien hinh Hl(79m); la 9600kN tUdng ufng coc H2(60m) ; la 10960kN tUOng lfng coc H5(80m) va la 7520kN tUOng ifng coc L2(60m).
3.3. sate chfu tdi cgc dttm nhd SWFC tdng theo thdi gian Cac thi nghiem ehai't tai cho cae coc bat dau tien hanh ttf 15/07 /1996 den 17/09/1996 cho den nay
(30/8/2008)cac coc da ttai qua gan 12nam. Vay sifc chiu t^i coc se dif bao la bao nhieu sau thdi gian 12 nam?
Tom tdt nghien cvtu sUc chiu tai cpc tdng theo thdi gian dddi ThU0ig Hdi.
Tif nhiJug nam 1950 cac nha nghien cufu va ky sif ThUdng Hai da quan tam khao sat kha nang mang tai ciia epe tang theo thdi gian. Nhieu so heu gia tri da dUde tieh IGy. Cae sd heu nay chi ra rang kha nang mang tai doi vdi coc ddng ti le tang tif 20% den 60%.
Tai dau cpc da't cuTng hdn thi ti le tang kha nang mang tai ldn hdn. NgUdc lai dat mem hdn tai dau coc thi ti le tang kha nang mang tai thafp hdn. Ttf dac tnfhg cpc ddng truyen thdng vdn cd d ThUdng Hai, mpt so' toa nha xay dtfng tnfdc day tren nen be-cpc nay da cdi tang ma tinh trang nha van dn dinh binh thudng.
De thien ve an loan ti le, kha nang mang tai cua cpc tang theo thdi gian lay bang 30%. Vi vay kha nang mang tai gidi ban ciia cpc du'dc tang len Uif di life ma sat gidi han tUdng u'ng dp sau cam cpc, roi lay ket qua nay chia cho he so' an loan bang 2. Do dd coc d'ng thep D700 mang ki hieu HI(79m), H2(60m) ,H5(80m) va L2 (60m) cd kha nang mang tai cho phep tUdng tfng la 6917kN, 5232kN 5677kN va 3912kN. So Ueu trong Bang 4 ttinh bay ke't qua so sanh tinh theo LERRA va theo tae gia tinh cho Tda Nha SWFC cho he so' an toan cao.
4. PHAN C^IA TAI TRpNG GlCfA CQC VA MONG BE DOI y 6 l HAI TOA NHA
So' lieu tieu bieu d trong va ngoai nUdc ve phan ehia tai trong giiia cpc va mdng be dUdc tdm tat trong tai heu 12, trong dd cd 4 phUdng phap de tinh toan stf phan ehia tai trong giu'a cpc va mdng be hoac mong hop dUdc nhdm nghien cufu gidi thieu. Sau day chi trinh bay bai phUdng phap thifc tien dUdc su" dung de phan tich stf phan chia tai trpng giiia epe va mdng be do'i vdi tda nha Jinmao va SWFC.
4.1. Phdn tich vi^c phdn chia tdi trpng giita cpc vd mong be ddi vdi toa nhd Jinmao
Phuong phdp thuc hdnh don gidn.
Pp =P- [pw-h(5%- 10%)p] A
Pp = Tong tai Uong cong Uinh truyen len mdng coc chiu,
P = P/A (t/m-) ap lUe trung binh tai day ban mong be,
p = long tai uong = 3 000 OOOkN =300 000 tan, A = dien tieh day mdng be = 3 519m-,
pw = ap life nUdc day ndi nUde ngam (t/m") Phuong phdp bdn kinh nghiem, nda ly thuyet Pp = S n d Eo / C
S = dp lun cpc = 0,048m n = so lifdng cpc = 429
d = dudng kinh coc 6'ng thep =0,914rn
Eo = Modun dan hoi eua he cpc - da't = 3300t/m' C = dUa vao L/d, Sp/d, n va bang , ta ed C= 2,93 D o d o Pp/P = 0,707 = 70,7%
Vay ti sd Pp/P tinh theo hai phUdng phap cho gia tri nhu nhau.
4.2 Phdn tich vifcphdn chui tdi trpng giOa cpc vd mong be doi vdi toa nhd SWFC
NGl/dl XAY DUNG SO THANG 11 • 2009
THllf Dif BAG B A N G PHl/ONG P H A P SO SANH...
Bang 2: So sanh kha nang chiu tai cho phep cua cpc tinh theo tac gia v i tinh theo LERA Soklhifeu
cpc thl nghidm chat
tai
HI (79m) H2(60m) H5(80m) L2(60m)
(l)kha nang mang
tai coc inh theo tac gia(kN)
6917 5232 5677 3912
(2) kha ning mang tai ciia coc tinh theo Leslie E.
Robertion Associate(kN)
5800 4300 5700 3200
(l)/(2)
1,193 1,217 0,996 1,223
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Hinh 2 - Mat bang bd tri mong cgc tda thdp vd nhd quay
Anh 2: Tda nhd Kim Mdu (JB) Chu thich:
1. Neil xet den ap lUc nifdc day noi , khi coc dong sau 19,65m de ddn gian, lay ap life nUdc ngam bang 19t/m2, thl Pp / P= 0,697 « 70%. Coe chiu 70% long tai
2. Khi ap life day ndi khong xet vi difdi mong nha quay phu ldp tha'm dUdc, be chju tai lay bang 8% tdng tai Uong, vay Pp /P=92%. Cpc chiu 92% tdng tai trpng.
3. Vi vay dp lUc day ndi la van de quan trpng ddi vdi m6ng hh.
4.2.1 Phuong phdp thuc hdnh don gidn
TUdng tif, de thien ve ddn gian thi ap life day ndi nUde ngam lay bang 18t/m-, do do Pp = 0,67=67%
4.2.2 Phuong phdp bdn kinh nghiem, nda ly thuyet Ttfdng ttf, Pp/P=0,77=77%
Nhu vay gia tri cua Pp/P phu thuoc vao mifc do xem xet cua ap life nUde ngam day ndi tae dung len be-coc.
5. CHIEU DAY CUA BAN MONG DOI VCfl HAI TOA NHA
O ThUdng Hai, vao nhifng nam 1980 theo thdi quen truyen thdng nUdc ngoai, thie't ke chieu day eua ban mdng be thudng lay bing cap so' nhan 10cm vdi sd lu'dng tang cao nha, dan den chieu day mdng be va ban day phang thiet ke khdng hdp ly. Vi du ehpn chieu day ban mdng be bing 4m eho tda nha cao 43 tang. Song Cty SOM thiet ke chieu day ban mdng be cho Tda nha Jinmao cao 88 tang chi cd 4m, thtfc te ebi ra rang thiet ke nay diing va tfu viet. Chieu day ban mdng be Tda nha SWFC, dUde kiem tra theo Tieu chuan nen mdngTrung Qudc cho tha'y thie't ke chpn 4,5m la thda man.
Tuy nhien lam sao dinh nghia dUdc chieu day ban
mdng se phdi than^ khiio tai Ufeu khic.
6. DO LtJN DOI V 6 l HAI T 6 A N H A 6.1 Phdn tich dp lun ddi vci toa nhd Jinmao 6.1.1. Quan trac do lun cua tda nhd Jinmao
Cdng Uinh nay da hoan thanh ngay 28 thang 8/1997. Sd chu ky quan u l c hin tda thap la 149 ky, bit dau tuf ngay 5 thang 10/1995 den ngay 1 thang 4/2003. Hmh 3 va 4 trinh bay dp liin ciia thap.
Dp liin ldn nha't tai tam dien tich dng ldi cu'ng diem M7 la 82mm, trong khi dd dp lun nhd nha't tai gdc mdng, diem Ml la 44mm. Tren cd sd dp lun M l - M l 3 la ddi xiJng, bien dang nhU ehuyen vi theo chieu dpc.
Dp liin trung binh tai diem Ml - M l 3 la 59,4mm trong khi dd dp liin trung binh tai cac diem M7, M4, M6, MIO va M8 tai mpt phan gdc mdng la 77,4mm.
Phil hdp vdi qui dinh theo Tieu chuan ThUdng Hai thi hien nay dp liin nay dtfdc xem la dn dinh.
6.1.2. Phdn tich hSn hop dg lun ddi vdi toa nhd Kim Mdu (Jinmao)
Day la lan dau tien phUdng phap ly thuyet ddn gian, phUdng phap nu'a ly thuyet , phifdng phap ban kinh nghiem , phUdng phap thdng ke dUde suf dung de dif bao dp lun va bay gid la phUdng phap hon hdp du'dc suf dung de phan doan danh gia dp liin.
Mpt day dp liin theo tinh toan = 9 1 ~ 122mm Bay gid dp lun ldn nha't theo quan ttac Mn la 82nim
6.2 £)p lun du bdo cho toa nhd SWFC
TUdng tif mpt day dp liin theo tinh loan = 81 - 132mm
Dd liin ldn nha't dUde dU bao se ldn hdn 82mm.
« M •) 4 »
Hinh 3: Mat bang bd Hinh 4: Dudng cong liin ciia tri cdc diem do liin. mgt ddy cgc.
6.3. Nhdn xet • ddnh gid dp lun ddi vdi hai Toa nhd Tda nha SWFC khdng the huy dpng dUdc kha nang mang tai gidi ban cua cpc vi dp manh ldn hdn tieu chuan (L/D>100) va moment udn ldn (28 000 OOOkN-m), dac biet dd'i vdi dien tich mdng cua SWFC ldn hdn 1,7 lan dien tinh mdng cua tda nha Kim Mau, vi vay anh hudng den chieu sau dp liin cua tda nha SWFC tbi ldn bdn tda nha Kim Mau, sd heu mang tinh phan tich mdng be cpc ddi vdi hai tda nha d Bang 8 ciing chi ra ring dtf bao dp liin cua tda thap SWFC ciing ldn hdn liin d tda thap Kim Mau.
7. PHAN TICH LY THUYET TAC DQNG
T U O N G H O (TUONG
TAC) MONG BE - CQC
Ly thuyet ve tac dpng tUdng ho giita ket eau ben
NGl/dl XAY Dl/NG S6 THANG 11 . 2009
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THfir b\f BAG B A N G PHl/ONG PHAP SO S A N H . . .
tten mat dat va mdng b^-coc da difdc gidi thieu d Xki Ueu [Zhao XH & al. Theory of Design of Piled raft and box Foundation for tall Buildings in Shanghai (in Chinese, 1989, Enlarged edition in EngUsh, 1998, Tongji University Press)] va da dtfdc suf dung de phan tich tae dpng tifdng ho mdng epe sieu dai ddi vdi tda nhi sieu cao tang d Thifdng Hai tai heu [Zhao XH, Gong j and Zhang BL. A study on super long pile foundation interaction for supertall building in Shanghai, computers and Geoteehnies J, 2004. in press]. Bay gid de ddn gian ttong viee so sanh mpt each tdm tat giiia tda nha Kim Mau va Trung tam Tai chinh The gidi ThUdng Hai, chi xem xet tac dpng tifdng ho giiia cpc va mdng be va se khong xem xet viec phan chia tai ttpng giCa be va epe. Cae ket qua tinh toan tai ttpng vao nhdm cpc va moment len mdng be dUdc gidi thieu tten hinh 5 va Hinh 6.
Tif viec so sanh cac tai ttpng tten nhdm cpc va tifng sua't ttong mdng be giiia tda nha Jinmao va Trung tam Tai ehinh The gidi ThUdng Hai, cd the eho tha'y ring thie't ke mdng be-cpc ddi vdi Trung tam Tai chinh The gidi ThUdng Hai la bap dam an toan.
8. NHAN XET VA KET LUAN 8.1. Khd ndng mang tdi cua cpc
Thilc te xay dtfng da chi ring kha nang mang tai cho phep cua epe ddi vdi tda nha Kim Mau la hdp ly.
Cdn ddi vdi Trung tam Tai chinh The gidi ThUdng Hai kha nang mang tai cho phep cua cpc dUdc tinh den tang theo thdi gian cung hdp ly. Mac dau cpc D7(X) ed dp manh L/D > 100, kha nang phan life moi cpc cd the anh hudng den moment . Dtfa theo thiet ke cd sd ,moment do gid gay ra la 28 000 OOOkN-m lam tang len 1/3 tai ttpng tinh se phai cpng them vdi tai ttpng thang difng, dUdi dieu kien nay thiet ke' phai chu ^ lay he so' an toan cao. Lay vi du tdng ap life day noi cua nUdc ngam ehi ap dung bing 60%.
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Tda nhd Jinmao Tda nhd SWFC (I) Trudng hgp cd xet dp (2) Trudng hgp khong xet
lUc nudc day noi dp luc nudc day noi Hinh 6: Moment phdn bd dge tuye'n giita
^ 8.2- Dif bdo phdn chia tdi trpng giiia cpc vd mong bdn be
1. Ddi vdi tda nhi Kim Mau, tai tda thip va nha quay mdng hh dUde ndi hen hen tuc bing mdi ndi khdp va de xet de'n life day ndi ciia nUdc ngam can thiet dUdc ttii mpt ldp tham dUdi diy mdng nha quay.
Song nd anh hudng den stf phan chia tai ttpng giffa cpc va mdng be ciia toan bp mdng tda nha.
2. De CO ldi cho an loan ddi vdi Trung tam Tai chinh The gidi ThUdng Hai thi ap life day ndi eua ntfdc ngam can xet den 60%. Nhiing phUdng phap de U'nh toan Slf phan chia tai ttpng giffa cpc va mdng be dffdc ttinh bay ttong bai nay se khdng ehi eung ca'p mpt cd sd dff heu iam giam sd lffdng cpc ma cd the tham khao de danh gia he so' an loan ki thuat ttong xay dffng nen mdng eong trinh.
8.3 Chieu day bdn mong be
1. Tda nha Kim Mau Cdng ty SOM da thiet ke chieu day ban mdng 4m la dat an loan can thiet va la thiet ke mdng td'i ffu. Dieu nay ddng gdp vai ttd quan ttpng nhim giai quye^t van de soat xet cai tien Tieu Chuan Thiet ke eua Trung Qud'c.
2. Cdn ddi vdi Trung tam Tai chinh The gidi Thffdng Hai ehi siif dung chieu day 4,5m la du can thiet va thda dang ma tten cdng trffdng khdng can bat cff mpt so' Ueu thi nghiem nao ve chieu day mdng hb ldn hdn 4m. Ngay nay, d Trung Qudc, chieu day thiet ke' ban mdng be nay dffdc duy tti. Vdi muc dich thiet ke hdp ly,dffdc hffdng dan thiet ke -ket hdp thi nghiem hien trUdng, ddi vdi tda nha sieu cao tang d Thffdng Hai, chieu day ban day be dffdc phep lay tff 4m - 6m cho mdng be - cpc sieu dai.
8.4 DUbdo dp lun tdng
1. Viec phan tich hon hdp dp liin dffdc ttinh bay ttong bai nay nhim de dff bao dp liin ddi vdi tda nha Jinmao da dffdc ttai qua thffc te la kha thi (cd the thilc hien dffdc).
2. Difa tten so Ueu do lun va phan tich hon hdp dp lun vdi tda nha Jinmao va phan tich hon hdp dp lun vdi tda nha Trung tam Tai ehinh The gidi Thffdng Hai, thi tda nha SWFC duf bao dp lun se khoang 10cm.
8.5 Ly thuyet thiei kemong be- cpc
Difa tten phan tich hai tda nha ed mdng be - cpc sieu dai ddi vdi tda nha sieu eao tang thi nha't thiet phai kiem tta hien trffdng ttang thai ffng suai't dan hdi tinh. Dffdi dieu kien nay ly thuyet tffdng tae (tac dpng tffdng ho) giffa ket ca'u tten mil dat va ke't ca'u mdng dffdi mat da't cd the dffdc suf dung de thiet ke mdng be - epe. Sff so sanh giffa tda nha JB va tda nha SWFC tai muc 7 da chi ra ring ly thuyet tffdng tae da ttinh bay ttong bai vie't nay la hoan loan hdp 1^ va cd thffc tien.
Neu xem xet y tffdng phan chia tai ttpng giffa cpc va ban be thi thiet ke mdng be-cpc se dem lai ldi ich kinh te dang ke nhieu hdn .
Dffa tten phan tich hon hdp da de cap d tten, ed the khang dinh mpt dieu la dieu kien ben va dn dinh tda nha Kim Mau (Jinmao) dam bao ra't tdt, ddi vdi tda nha Trung tam Tai chinh The gidi Thffdng Hai thi he sd an loan, tin cay ve ky thuat mdng be- cpc chic chan cdn tiem tang nhieu hdn nffa.Q
NGl/dl XAY Dl/^G S6 THANG 11 - 2009
