_?_NGHl|NCuru KHOA HOC Thi cong dai mong khoi lan bang phiFang phap do be tong lien tuc kit hap phan chia lap do vai cap phoi va SLP toa nhiet khac nhau Ngay nhan bai: 10/12/2013 Ngay
Trang 1_?_NGHl|NCuru KHOA HOC
Thi cong dai mong khoi lan bang phiFang phap do be tong lien tuc kit hap phan
chia lap do vai cap phoi va SLP toa nhiet khac nhau
Ngay nhan bai: 10/12/2013
Ngay sita bai: 15/12/2013
Ngay chap nhan dang: 30/12/2013
Ho Ngpc Khoa
T O M TAT:
Trong thi cong be tong dai mong khoi ldn nha sieu cao tang noi rieng va ket cau be tong
khoi Icin noi chung, van de quan trpng nhat la kilm soat diiac mJt do hieu iJng nhiet
thuy hoa xi mang trong khoi do ma van phai dam bao dilpc tinh toan khoi, kha nang thi
cong lien tuc va tinh chong tham cao cho cau kien Bai bao the hien ket qua phan tich ly
thuyet, ca scf khoa hpc ve qua trinh vat ly xay ra trong be tong kh6i ldn d giai doan dau
dong ran va ket qua nghien ciJu thilc te qua trinh thi cong dai mong cong trinh sieu cao
tang Lotte Center Hanoi, tii do de xuat quy trinh cong nghe thi cong be tong lien tuc dai
mong kh6i Icin nha cao tang va sieu cao tang bang phUPng phap do be tong lien tuc ket
hpp phan chia Ictp do vdi cap phoi va stf t6a nhi^t khac nhau Ket qua nghien ciiu co the
tham khao, sil dung trong viec lap philong an cong nghe - to chiJc thi cong cac ket cau
be tong dai mong khoi ldn trong dieu kien khi hau Viet Nam
ABSTRACT
In the cpnstruction of mat foundations of super high-rise buildings as well as other
mass concrete structures, the most crucial issue is to control the cracking caused by
the heat of cement hydration Moreover, it is desirable for the concrete structure to
achieve the unification property, uninterrupted construction and high water-repellent
capability This article reports the theoretical analysis, scientific fundamental of
the physical process happened in the mass concrete during the initial stage of the
hardening process, and the research result obtained from the construction of mat
foundations pf the Lptte Center Hanpi With these research findings, a prpcedure pf
cpntinous construction of mat foundations for high-rise and super high-rise buildings
is proposed This procedure is established based on the countinuous cpncrete ppuring
technique with multiple ppuring layers accprding tp different cpncrete mixtures and
heat hydratipn The research results can be used as a reference fpr establishing the
cpnstructipn methpd and management of mat fpundatipns in the climate condition pf
Vietnam
Keywprds: mat fpundatipn, mass cpncrete, heat hydratipn, cracking cpntrpl, super
high-rise buildings
TS H6 Ngoc Khoa
Khpa XSy dttng Dan dung va Cdng nghiep
Email: hnkhpagiyahpp.cpm
Trildng Dai hpc Xay dilng
Mddau:
Mong la mot trang nhufng ket cau chju lUc
CO ban va quan trong nhat cCia cong trinh xay dung Mong tiep nhan toan bo teii trpng phan ket cau ben tren va hoat tSi sir dung cua cong trinh, phan phoi va truyen xuong nen, quyet
djnh den tinh on djnh va do ben cua ci cong
trinh Doi v6i nha sieu cao tang thi phan ket cau mong cang the hien duoc vai tro quan trong nay Trong thcJi gian gan day, d Viet Nam mot so cong trinh nha sieu cao tang da hoan thanh dua vao sCr dung nhu Keangnam Hanoi Landmark Tower, Bitexco Financial Tower (TP Ho Chi Minh); sap hoan thanh nhu toa nha Lotte Center Hanoi; dang thi cong nhu VietinbankTower (Ha Noi) SUxuat hien cua cac toa nha sieu cao tang nhu la mot bleu tupng the hien su dang cap cua do thj ve kien true
va xay dung, phein anh phan nao sU phat trien kinh te cua Viet Nam
Dai mong nha sieu cao tang la ket cau be
tong cot thep co kich thudc theo ci 3 phuong
va khoi tich rat ldn, den hang nghin m3, do do qua trinh thi cong gap rat nhieu khd khan ve mat to chiJc va ky thuat de dJm bao tinh toan khoi, khS nang thi cong lien tuc va kiem scat niJt cua be tong Van de nay lien quan den lUa chon cap phoi be tong, phuong an do be tong
va phuong an bJo dUSng be tong vdi nhOng kho khan va phufc tap trong dieu kien khi hau ndng am d Viet Nam, noi ma sU bien thien cua nhiet dp, dp am khpng khi thay doi lien tuc, khong chi trong thang, ma tham chi trong ngay
Qua trtnh xay dung cac cong trinh nha sieu cao tang d nUdc ta keo theo sU xuat hien (ap dung) cac cong nghe thi cong mdi hien dai, trong dd co cdng nghe thi cdng be tdng lien tuc dai mdng khdi Idn vdi viec sCr dung 2 cap phdi be tong cung cudng dp nhUng cd tinh chat tda nhiet khac nhau trong mdt cau kien Day 1^ cdng nghe mdi, lan dau dupc ap dung
oi.2oi4Bninn:[iBi g i
Trang 2thay dupc nhijfng Uu diem vuot troi trong viec
kiem soat nut do ilng suat nhiet de dam bao
chat lupng cOa be tdng dai mong khdi Idn Tuy
nhien, viec tinh toan, thiet ke bien phap cdng
nghe - t d chdc thi cong duoc thUc hien bdi cac
chuyen gia nUdc ngoai, ddi vdi cac chuyen gia
trong nudc thi ly thuyet va kinh nghiem thuc
tien ve van de nay con han che Do dd, viec
nghien cufu cd sd ly khoa hpc va sd lieu thuc te,
tCf dd phan tich, tdng hpp de de xuat qui trinh
cdng nghe thi cdng co ban lam cP sd ap dung
chp thi cpng cac ket cau tuong tU la het siIc can
thiet va CO y nghTa thUc tien cao
1 Cac qua trinh vat ly xiiy ra trong be
tong d giai ctoan ctau ctong ran
Viet Nam nam trong vung khi hau nhiet
ddi gid mCia, vdi hai thupc tinh cP ban la ndng
am va phan hda theo mua ro ret Su bien thien
trong ngay cCia nhiet dp va do am trong nhieu
chu ky thdi tiet la rat Idn, chenh lech nhiet dp
cd the dat 10 ^ 150C, dp am: 45 H- 50% Cac yeu
t d khi hau: nhiet dp, dp am khdng khi, tdc dp
gid, bufc xa mat trdi anh hudng rat Idn den qua
trinh ddng ran cCia be tdng, cung nhu den cdng
nghe thi cdng dedam baochat lupng va duy tri
cac cdng nang thiet ke cua cau kien Mot mat,
khf hau ndng am thuc day qua trinh ninh ket va
dong ran cCia vCfa be tdng, tang nhanh tdc dp
phat trien cudng dp, rut ngan thdi gian thao van
khudn Mat khac, nhiet dp mdi trudng cao, dp
am thap, tdc dp gid cao se lam tang nhanh qua
trinh bdc hPi nudc, phat trien bien dang mem,
hinh thanh trudng nhiet dp va dng suat khong
ddng deu trong be tdng d giai doan dau dong
ran, anh hudng xau den cau true va sU phat
trien cudng dp cuoi ciJng cua be tong [2]
Su ddng ran cua be tdng la ket qua cua
hang loat cac qua trinh hda hpc, vat ly dien ra
ngay sau khi dd be tdng DUdi tac dpng cua cac
yeu td khi hau, xay ra cac qua trinh chuyen djch
vat chat ben trpng be tdng, trao ddi chat gida
be tdng va mdi trudng xung quanh va ket qua
tiep theo, cd lien quan chat che vdi cac qua trinh
tren la sU bien dang the tich cua bSn than be
tong Cu the, cd the liet ke: qua trinh mat nudc
(bay hPi nudc); qua tnnh thay ddi the tich (bien
dang mem: co va nd); qua trinh djch chuyen va
thay ddi nUdc va ap luc hoi trong be tdng; qua
trinh thay ddi nhiet dp trong be tdng; su hinh
thanh dng suat trong Idng khdi be tdng
Trong so cac qua trtnh tren, phai ke den mpt
SP qua tnnh co ban nhU: qua trinh mat nudc, thay
ddi the tich (bien dang) va thay ddi nhiet dp Cac
qua tnnh nay xay ra ddng thdi, lien quan lan nhau,
chju tac ddng cua cac yeu td ben trong be tdng va
cac yeu td t d mdi trudng ben ngoai Qua trtnh mat
nudc dan den cau true rong va bien dang mem
be tdng, bien dang mem gay nuft mat be tdng; su
thay doi nhiet dp trong Idng khdi be tong dan den
sU ch#nh lech nhiet dp gida cac Idp be tdng vdi
nhau va vdi mdi trudng ben ngoai dan den nuft
eudng dp va eac tinh chat cd - ly cCia be tong vi
sau Nhieu tai lieu da nghien cilu va khang djnh van de nay [1,13,14,15] De khac phuc nhufng van
de tren can phai cd mdt giSi phap ve cdng nghe thi cdng va bao dudng be tdng phu hpp, tuy theo kich thudc cua khdi be tdng
2 TrUdng phan bo nhiet do, urng suHt
trong dai mong be tdng Ithdi idn ichi dong r i n
Theo [1,13], thanh phan hda hpc cua xi mang pppclang thdng thudng ehufa nhieu cac khoang clinke va mdt lupng nho pha thuy
tinh, CaO, MgO va kiem t u dp Na^O, Kp Khi tac
dung vdi nUdc, eac khoang clinke thuy hda tao thanh eac khoang tinh the mdi cho cUdng dp
va giai phdng nhiet Cae phan ufng thuy hda
la eae phan ufng tda nhiet Luong nhiet tda ra sau 3 ngay thuy hda cua eac khoang CjA, C^S, C,AF, CjS, tUPng dng la 590,405,176, va 63 J/g
Nhu vay, ro rang lUpng nhiet tda ra phu thupc chu yeu vao thanh phan cae khoang clinke, de han che lugng nhiet thuy hda cua xi mang phai hudng den giam thanh phan CjA va C^S trong clinke Trong be tdng khdi Idn, lupng nhiet tich
tu du gay hieu ufng nhiet lam nuft khdi be tdng
Do do trong be tdng khdi Idn thudng dung xi mang it tda nhiet, vdi lUpng n h i f t thuy hda sau
3 va 7 ngay tUOng dng khdng qua 168 - 188 va
210 - 230 J/g, va han che toi da lUOng dung xi mang de gi^m tfch tu nhiet trong khdi be tdng
Trong qua trinh ddng ran, cau trijc be tdng dupc dan hinh thanh va cd tinh dan nhiet thap
VI vay lupng nhiet thuy hda xi mang tda ra khdng kip thoat het ra ngoai va tfch tu trong long khdi
be tdng, gay nen dp chenh lech kha Idn giufa cac ldp ben trpng va b l mat thoang Theo thdi gian, nhiet dp trong khdi be tdng se giam dan tdi mdc
dn djnh Qua trinh thay ddi nhiet dp eua be tdng khdi Idn cd the chia ra lam 3 giai doan: tang nhiet
=> giSm nhiet => dn djnh nhiet (hinh 1), n h i | t dd eao nhat trong Idng khdi be tdng cd the xac djnh theo cdng thdc:
T™, = T, + T , (1) Trong dd:T^ - nhiet dp be tdng khi dd;
T^j - nhiet dp phat nhiet Idn nhat cua chat ket dinh
Td nhiet dp J^ den T^^^ la giai dpan tang
nhiet, sau khi dat den Tmax thi nhiet dd trpng
be tdng giam dan gpi la giai doan giam nhiet,
va cudi cung la giai doan dn djnh nhiet khi nhiet
dp trong khdi be tdng dat gia tri dn djnh
Hifih 1 Cac giai doan thay 46i nhiet Jo ciia he tong Ichoi \6n
be tdng tang lien tue trong khoang 4 -f 7 ngay dau ddng ran hoac Bu hon tuy theo khdi tich
be tdng Nhiet dp cCia phan be tdng phia trong khdng ngdng tang ISn cho den khi dat gia trj nhiet dp tdi da Tmax Gia trj nhiet dp tdi da eua
be tdng khdi Idn chiu inh hudng cCia nhieu yeu
td, nhU: thanh phan cap phdi be tdng; loai va lupng xi mang; nhiet dp vda be tdng khi do;
nhiet do mdi trudng; phuong phap thi cdng Be tdng sCr dung xi mang cd nhiet thuy hda cang cao thi nhiet dp tdi da cang cao Theo [10] sil dung eac loai xi mang pooclang tda nhiet thap
va thay the mdt phan xi mang bang tro bay lam gicim gia trj nhiet dp tdi da eua be tdng khoi Idn
Khi dung 1 Okg/m' xl Id cao hay tro bay thay the
xi mang pooclang thudng, thi nhidt dp giSin tuong dng la 0,5°C -^ 1°C Ngoai ra, viec sddung phu gia hda hpc n h u phu gia giSm nude, phu gia cudn khi, phu gia sieu d4o ngpai tac dung lam giam ham lugng xi mang, cdn cd tac dung
lam giam nhiet dp trong bi tdng khdi Idn, dac
biet la trong giai doan tang nhiet
Trong qua trinh tang nhiet, sutda nhiet chij
yeu dien ra d cac Idp bi tdng be mat, do bj lam
ngudi bdi mdi trudng khdng khi Tdc dp tda
nhiet cua khdi be tdng t) le thuan vdi ty sd dien
tfch be mat thoat n h i | t trdn khdi tich be tong
(he sd bi mat thoang M ^ J Theo [11], danh
gia su khuech tan nhiet dp trpng khdi be tdng
cd can cd vao mdc dp khuyech tan nhiet dp h^
(mVh), duoc xac dinh theo cdng thdc (2)
' =Z-p (2)
Trong dd:
K - d o dan nhiet (KJ/m.h.°C);
C - nhiet rung rieng (KJ/kg.°C);
p - khdi lugng rieng cua be tdng (kg/m^)
Gia tri khuech tan cang cao thi khci nang t6a nhiet cang de dang hon Gia trj khuech tan phu thudc vao loai edt lieu Idn sd dung trong thJnh phan be tdng Su mat nhiet ciJa cac Idp be tdng phfa ngoai cd t h i tao nen chenh lech nhiet do vdi cae Idp phfa trong gay ufng suat keo dCi ldn lam ndt be tdng
Giai doan ha nhiet cd the bat dSu sau 4
-10 ngay hoac lau hon, phu thudc vao khdi tfch
cua k i t ciu Ddi vdi cac k i t eau dai mdng Idn,
qua trinh ha nhiet ed the keo dai hang thang
Trong giai doan nay, eac Idp be tdng phia trong
se ngudi dan va co lai lam phat sinh dng suat keo trong be tdng Qng suat nay duoc tfch tu theo thdi gian, cd the gay cac v l t ndt xuyen, rat nguy hiem cho k i t cSu [1], Ddi vdi cac ket cau be tdng khoi Idn ( M ^ , , nhd) thi luong nhiet thoat ra cham, trang khi nhiet do trang Idng k i t ca'u lai cao, dan den su tao thanh trudng nhiet
dp khpng ddng d i u theo the tich, cd t h i anh huong den su hinh thanh ca'u trde, chat luong
va cuong do be tdng
Theo [11] nhiet dp trang giai doan g i j m nhiet tai mpt vj tri bat ky each be i.^at mdt
92 BWniEifSIl 01.2014
Trang 3I n
^ ^ e Vh^T (3)
Ro
Trong do: R,^ - nhiet dp tai vj tri each be mat
mpt khoJng x (m);
Rj - nhiet dp be mat (x = Om);
e - CO sd cOa logarit tU nhien (e = 2,718);
X khoSng each tai diem khSo sat (m); h^
-mufc dp khulch tan nhiet dp (mVh);
Y - thdi gian cCia chu ky nhiet dp b i l n ddng
trong ngay
Giai doan on djnh nhiet bat dau khi be tdng
giSm nhiet den g i i trj dn djnh Trong giai doan
nciy, nhiet dp trong khdi be tdng duy tri dn djnh,
sil thay ddi ve nhiet dp chCi yeu dien ra trpng
pham vi Idp be mat be tdng dp sU thay ddi cCia
nhiet dp mdi trudng
Trong thdi gian ddng rSn, tuy theo khdi tich,
lupng nhiet thCiy hda va mdc dp gId nhiet cCia
cKu kidn ma gia trj cung nhu sU phan bd nhiet
dp trpng khdi be tdng se khae nhau d tdng vj trf
Ve nguyen tac, sU phan bd nhiet dp be tdng d
mdi trudng nhiet dp cao dugc xac dinh bdi qua
trinh nhiet - 1^ xay ra trong be tdng giai doan
diu ddng ran 6 b l mat thoang cCia be tdng (Idp
be mat), q u i trinh mat nhidt d i l n ra tuong dng
vdi hd sd dan nhiet cua mdi trudng (trong dieu
kien dp ^m lidn tuc thay ddi) (3 nhdng Idp phfa
dudi - tuong ufng vdi he sd dan nhiet cua Idp be
tdng phfa tren Cdn d nhdng Idp be tdng canh
khdi - sU mat nhiet phu thudc vao chCing loai
va hd sd dan nhiet cda vat lieu lam van khudn
Trong [3], trudng nhiet dp va dng suat khdi
mau be tdng dai mdng kfeh thudc 4600 x 4600
x 4000 mm dUOc phan tfch bdi phuong phap
phan tuf hdu han va so sanh vdi k i t qui do thue
nghiem Ket quJ nghien cdu cho thay nhiet do
trong khdi bd tdng dat gia trj Idn nhat d tudi 85
gid sau khi dd, khu vUe xung quanh tam khdi
mdng la noi cd nhiet dp cao nhat, diem cao nhat
cd nhiet dd 1^ 90,39°C (hinh 2a) Thdi gian dau
nhiet dp phan bd kha deu tai cac diem trong
Idng khdi bd tdng, nhUng cang v l sau vCing
xung quanh tam khdi nhidt dp tang cap ciing
vdi t h i tfch vung nay CP nhd lai Khf vda be tdng
v3n d dang Idng, khS nang ddi luu va truyen
nhidt tdt nen nhiet dd phSn bd deu Cang v l
sau, khi be tdng bSt dau ddng rin, nhidt lugng
ph^t ra tir phcin dng thuy hoa xi mang bj tfch
tu trong Idng khdf va lam nhiet do vung xung
quanh t§m tang rat cao
Cfng suat trong khdi be tdng d thdi gian
Siu sau khi do chii y l u la dng suat nen, dng
sutft keo chi xuat hidn chii y l u d mat thoang va
xung quanh Ceic gdc canh vin khudn (hinh 2b)
Khoing thdi gian nJy la giai doan tang nhidt
khdi be t d n g , khi do phan be tdng phia trong cd
xu hudng nd nhidt ndn dng suat phat sinh chO
y l u trong khdi la dng suat nen Trong khi dd d
mat thoang vi gdc van khudn bd tdng bi giSm
nhidt dp nhanh (ra mdi trudng khdng khf va qua
^ ^
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- 3 43087e*001
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a.TrirclngphSnhonhietdo Hinh 2 Phan bo nhiet do, iing suat trong Jai mong be tong lihoi ISn
bTririmg phan bo ling suat
Phan Cmg thuy hoa xi mang
- Giai phOng nhi$t Tich tu trong khoi BT
1 ru'6'ng nhi^t d6 cao
Chenh lech nhiet d6 AT
bJo
k>Rbk
Phat sinh tfng s u j t kdo S Sy thay doi the tich
Hinh 3 Co che gay niJt be tong khoi ldn van khudn) se cd xu hudng co, nhUng do bj cac Idp phia trong cd nhiet dp cao hon kim gidva la nguydn nhan phat sinh ra dng suat keo ciia Idp
bd tdng d nhdng vj trf nay
K i t quei phan tfch da md ta dugc qui luat thay doi va xac djnh dugc gia trj ciia nhiet do va dng suat tai eac vj tri va thdi diem ddng ran khac nhau ciia bd tdng, v l co b i n tuong dong vdi k i t qua do thirc t l bang phuong phap t h i nghidm hien trudng K i t q u i phan tich la eo sd d l thiet lap bien phap k i l m soat trudng nhidt dp va dng suat nhiet de chdng ndt cho be tdng khdi Idn trong thi cdng
Qua eac ket qua phan tfch tren, thay rang nguyen nhan co bSn gay ndt trpng be tdng khoi Idn la sU chenh lech nhiet dp (AT) gida eac Idp ben trong khdi bd tong vdi eac Idp ben ngoai
t i l p giap mdi trudng xung quanh Khi dp chenh lech nhiet do dii Idn sd gay ra hien tugng co gian khdng deu giiia Idp be tdng ed nhidt dp cap va Idp bd tdng ed nhidt dp thap hon Qua trtnh CO gian nay lam phat sinh dng suat keo trong be tdng, va khi vUgt qua gidi ban keo tai thdi d i l m do ciia be tdng thi sd gay ndt trong be tdng Co che ndt dugc md ta tdm tat d hinh 3
Theo [8], be tdng khdi Idn bj ndt do hieu dng nhiet thiiy hda xi mang khi cd dii 2 y l u t d sau day: dieu kien can - dp chenh lech nhiet dp
AT gida cac diem hoac eac virng trong khdi bd tdng vUgt qua 20°C (AT>20°C) va d i l u kidn dii -mddun chenh lech nhidt dp MT gida cae diem trpng khdi bd tdng dat khdng dudi 50°C/m (MT>50°C/m)
Nhu vay, de kiem soat ndt do nhiet trong
be tdng khdi Idn can p h i i kiem soat ehdnh lech nhidt dp gida cac Idp be tdng, gida trung tam
va Idp be mat trong gidi han chp phep Bi dat
dugc muc tieu dd, ed the ap dung eac bidn phap
thi cdng dudng sau:
Dua nhiet trong khdi be tdng
ra ngoai bSng dng chda nudc lanh de can bang nhidt dp gida eae Idp;
- Chia nhd khdi
be tdng, td chdc mach ngdng thi cdng, do tdng khdi bang nhieu lan dd gian doan;
- Can bang nhidt dp gida cac Idp trung tam
va be mat khdi be tdng bang giai phap cdng nghe thi cdng va b i o dudng
3 Cong nghe thi cong dai mdng khoi ldn bang phifcmg phap do be tdng lien tuc l(et hop phan chia ldp do vdi cap phdi va sil tda nhiet khac nhau
3.1 Casdkhoa hgc lUa chgn cong nghe thi cong
Cdng nghd thi cdng dai mdng khdi Idn bang phuong phap do bd tdng lidn tuc k i t hgp phan chia Idp dd vdi cap phdi va su tda nhiet khac nhau dugc ap dung lan dau tidn d Viet Nam khi thi cdng dai mdng cdng trinh Lotte Center Hanoi Dai mdng dugc thi cdng d tang ham t h d 5 cd kfeh thudc 92,7m x 44,1m, c h i l u day dai mdng t d 3 + 5,7m, khdi lugng bd tdng 17.030m3 Odi vdi mdt k i t eau dai mdng kfnh thudc sieu Idn nhu vay, cdng nghd thi cdng
p h i i dugc xem xet va lUa chpn vdi tieu chi quan trpng hang dau la kiem spat dupc ndt do hieu ling nhidt thiiy hda xi mang trong khdi do Ngoai ra, phuong an t d chdc thi cdng dam bao chat lupng k i t cau, t i l n dp va thuan Igi cung can nghien cdu de cd giai phap thfch hgp Phuong phap l i p dat dan dng thoat nhiet bang kim loai trong be tdng, sau do bom nude lanh qua dan dng de dUa nhiet ra ngoai da cho hieu q u i thoat nhiet kha tdt va cd the do
be tdng lien tuc Tuy nhien viec lap dat dudng dng va dam b i o bom nUdc lien tuc, thdng sudt qua dan dng gap nhieu khd khan.Trong trirdng hgp x i y ra sU cd n h u t i c dng, dng bj bep, bj
hd thi viec xd ly khic phuc tdn nhieu kinh phf
va cd the i n h hudng d i n chat lugng be tdng
01.2014B«ini:[|Bl 9 3
Trang 4I6p
be tong
Phia dirSi
Phia tren
T^le
N/(X+Tro
bay)
42%
39%
long li/tfng XM-i-Trobay (kg)
385
415
Vat lieu cho I m ' b e tong Cat
(kg)
880
840
fia (kg)
951
964
Xi mang (kg)
289
311
Tro bay (kg)
96
104
Niroic (lit)
160
160
Phu gia (sieu dio)
1,35%
1,35%
Bing 2 K i t q u i do nhidt dp khdi mau be tdng t h i
Vitri do
Trung tam
Canh bien
Goc
Lln tien hanh
Lani Lan 2 Lani Lan 2 Lani Lan 2
Nhiet do d tam khoi
70,4 77,4 67,1 74,3 63,2 71,2
ighiem
Nhiet do Idp be mat
56,1 57,0 54,3 55,2 52,5 53,2
Chdnh lech
14,3 20,4 12,8 19,1 10,7 18,0
Thi cOng \&p d^ng vAn khuOn
bjimg tihin t ^ cdch nN$t
U p d^mg c6t th^p h$ di6ng 60 c6t t h ^ ,
mdi che thang sdn cOng tdc Ihi^t bj do
nhidt do b& tfing cdc chj tl^l d4t s i n
L i p d3t 6ng bom bd tdng, t6 chi>c tr4n vd vdn chuydn vOd bdtdng
Od, d i m tid tdng d e l 1 ,
bd tdng It tda nhidt
Od ddm bd tdng det 2, bd tdng tda nhidt blnh thi/dng
Hodn thidn bd m$t bd tdng bdng mdy xoa
Bdo di/d'ng giC^ nhidt bd tdng, che mdt thodng bdng vdt lidu giO nhidt ttieo p h m m g dn
Didu chlnh nhidt dd bdo d i r t n g (tdng, bdi ldp giO nhi$t)
Kdt thOc bdo duCmg, thdo d d
vdn Ithudn, vdi ll$u b i o dudrng,
m d i t ^
Hinh 4 Quy trinh cong nghe thi cong dai mong khoi lin do
khac nhau
Mat khic, n l u dai mdng Idn, sd Idp dng nhieu
thi hidu q u i thoat nhiet (dae biet tai nhOfng noi
each xa dau cap nUdc lanh) la rat thap, khd dap
dng dugc ydu eau
Phuong p h i p chia nhd khdi dd eiia dai
mdng vdi muc dich g i i m khdi lugng bd tdng
mdt lan thi cdng, g i i m lugng nhiet thiiy hda
trong tdng khdi do, d l de k i l m soat hon Trong
phuong phap nay, can p h i i bd sung cae tam
chdng tham va mdt lugng thep kha Idn nham
be tong lien tuc ket hop phan chia ldp do vdi cap phoi va sir toa nhiet chju c i c lilc gay tach trugt tai vj trf d l mach ngdng, tir dd lam tang chi phf vat lieu Idn rat
n h i l u , ehua tfnh d i n vide thi cdng khd khan vi mat dp cdt thep day dac Ngoai ra phuong p h i p nay cung k l o dai dang ke thdi gian thi cdng dai mdng do cic g i i n doan ky thuat va thdi gian xd
ly mach ngdng thi cdng
6 cdng trinh Lotte Center Hanoi, sau khi phan tfch, so sanh va tfnh t o i n , phuong an do
be tdng lien tue k i t hgp p h i n chia Idp dd vdi
Hinh 4 Phan bo cac Idp do vdi be tong cd tfnh chat toa nhi^t khac nhau theo chieu cao dai mdng
cap phdi va su tda nhiet k h i c nhau dugc lira chgn d l thi cdng dai mdng Day la phuong phip
k i t hop ap dung ddng thdi hai bidn p h i p : kiem soat nhiet dp c i c Idp bd tdng bang d i l u tiet sir trao ddi nhiet gida bd tdng vdi mdi trudng bdn ngoai thdng qua bidn p h i p b i o dudng va can bang nhidt dp gida cac Idp trpng khdi bd tdng bang phan chia Idp (dot) dp vdi c i c cap phdi be tdng Cling cap dp ben nhung cd su tda nhiet khae nhau Ldp be tdng phia tren mat dai mdng
c h i l u day 1 m sddung xi mang pooc lang thdng thudng, vdi lupng xi mang -i- tro bay va lupng nhiet tda ra Idn hon rat nhieu so vdi Idp be tdng phfa dudi chieu day 4,7m sd dung xi m i n g tda nhiet thap, phu gia keo dai thdi gian ninh kit vdi Iggng xi mang -i- tro bay ft hon (hinh 4)
B i n chat cua phuong phap nay la tao ra mdt Idp "can bang nhiet" d phfa tren dai mdng bang chfnh vat lieu la bd tdng Be tdng - Idp "can bang nhidt" nay cd cap phdi d i m b i o k h i nang tda nhidt Idn hon so vdi phan be tdng edn lai ben dudi, nham can bang nhidt dp gida Idp be mat v i cac Idp d trung t i m dai mdng.Trpng q u i trinh b i o dudng, nhiet dp gida trung tam khdi
va Idp b l mat, nhidt dp gida be mat be tdng va
c i c Idp g i d nhiet (nhidt dp b i p dudng be tdng) dupc k i l m spat va d i l u chlnh bdi vat lieu va so lugng Idp phii g i d nhidt, can cd vao sd lieu do nhiet do Ngoai viec d i m b i o dugc k h i ning can bang nhidt do gida cac Idp, phuong phap nay cho phep thi edng dd bd tdng lidn tuc, khdng mach ngdng, d i m b i o tfnh toan khdi
va k h i nang chdng tham cita k i t cau, tao dilu kien cho viec to chdc thi cdng va kiem soat chat lugng bd tdng dai mdng tdt hon
Bd tdng dai mdng cdng trinh Lotte Center Hanoi dugc thiet k l cd eudng do C4a (tidu
c h u i n My ACI), t u len, dp chay 650 m m , sd dung
xl mang tda nhiet thap, mdt phan xi mang dUOc thay the bang tro bay vdi muc dfch lam g i i m lugng dung xi mang t d d d lam g i i m luong nhidt thdy hoa Cap phdi chi tiet vda be tdng Idp tren
va duoi cua dai mdng t h i hidn d b i n g 1
Be kiem chdng va hidu chinh c i c thdng sd
cong nghe trudc khf thi cdng, mdt thi nghidm hien truong dupc thuc hien trdn khdi mau be
4SDiiniBIX 01.2014
Trang 5Cong tac
Lap PA CN-TC
thi cong
Thi cdng lap
di/ngvan
khudn dai
mdng
Lap dat tam
giO nhiet
cdng vdi VK
thanh mdng
Thi cdng lap
difng cdt thep
da mdng
LSp dat dung
eg, thiet bj do
nhiet do
trong be tdng
Che trdn vda
betdng
Van chuyen
vda betdng
tir tram trdn
den cdng
trirdng
Van chuyen
vua be tdng
bang may
bdm den vitri
do be tdng
fid, dam be
tdng
Biodirdngbe
tdng dai
mdng
l l i a o d d van
khuon
Noi dung
1 Thf nghiem, tfnh toan
2 Lap, phe duyet PA cdng nghe-td chdc thi cdng
1 Gia cdng, to hop tam khuon
2 Lap dimg van khudn thanh mdng
3 Dd be tdng tudng chan dai mdng (neusitdung vdn
titmdn labi tong dt ttiep)
4 Kiem tra, nghiem thu
1 Van chuyen tam giUnhietden vj trf thi cdng
2 Lap dat tam gid nhiet lien ket vdi van khudn thanh
mdng
3 Kiem tra, nghiem thu
1 Vdn chuyen cdt thep den vj trf thi cdng
2 L3p dung cdt thep da mdng v a he gia dd cdt thep
3 Lap dat cac chi tiet dat san, chdn ngam trong dai
mdng
4 K.tra va nghiem thu
1 Lcip dat thiet bi do nhiet do trong be tdng va nhiet do
baodirdngbetdng
2 LSp dat cac dung cu bao ve thiet bi do nhiet dp
3 Kiem tra va nghiem thu
1.Chuan bjvatlieu
2 Thiet ke cap phdi
3 Cap lieu (cdt lieu, nirdc, xi mang, phu gia)
4 Trdn vfla
1 Trut vda td thung trdn vao bdn xe van chuyen
2 Van chuyen den cdng tnrdng
3 Kiem tra tinh thi cdng (do sut, do chay) cua vfla
4 fiuc mau thf nghiem kiem tra cudng do be tdng
1 Trut vfla tif xe van chuyen vao thung chda may bdm
2 Van chuyen vfla trut vao vj tri dd
1 fid, san gat vda
1 6 a m be tdng
1 Hoan thien be mat be tdng
2 Trai cac Idp vat lieu che be mat be tdng theo phflong
an bao dudng
3 Theo ddi (do) nhiet do be tdng
4 Thay ddi bien phap bao dudng neu can thiet
5 XiJIy so lieu do nhiet dp, xac ffinh AT, quyet djnh ket
thuc bao dudng
I.Tliaoddvatlieugiflnhietvavankhuonthanhmdng
2 Thao dd mai che
Chi dan bien phap, ky thuat thi cong, tieu chuan ap dung
Viec thi nghiem, thilc nghiem xac djnh cac thdng sd ky thuat phuc vu thiet ke bien phap cdng nghe - td chdc thi cdng thflc hien theo phflong an cua ky sd phu trach
Lfla chpn chdng loai van khudn (kim loai, gd, be tdng cdt thep) theo phflong an cdng nghe thi cdng
Xac nhan ban ve ket cau va cau tao van khudn
Kiem tra tfnh toan he van khudn theo [6]
Xac nhan xuat xfl, chung loai vat lieu, phfldng thflc che tao
Che tao van khudn tuan thu [6,8] va cac tieu chuan khac phu hgp
Lap di/ng van khudn tuan thu [6,8,9] va cac tieu chuan khac phu hgp
Van khudn bang BTCT thi cdng theo cac quy dinh trang [6]
Chung loai tam gifl nhiet theo phflflng an cdng nghe thi cdng (thfldng dung tam xdp polystyrene hoac polyurethane day 4-5cm,cd khdi lflpng the tich >20kg/m',dpam < 1 2 % )
Xac nhan ban ve va phflong an thi cdng
Jam vat lieu gidnhiet phai dflpc boc ap sat mat ngoai van khudn thanh trflde ldc do be tdng Can cd bien phap che chan mat ngoai de chdng am vat lieu each nhiet
Xac nhan ban ve ket cau, nghiem thu vat lieu va phe duyet phfldng an thi cdng
Van chuyen va lap dung cdt thep tuan thu [6] va eae tieu chuan khac phu hdp
Ndi cotthep (bang dng ren] dam bao eae yeu cau ky thuat theo [6,7] va eae tieu chuan khae phu hop
He gia ddeae Idp cdt thep trong dai mdng Sflfle ke tai nhflng vi tri dam bao khdng lam bien dang Idp edt thep phia dfldi Kiem tra chat Iflong, mdi ndi, neo edt thep
Thiet bi do nhiet dd tfl ddng vdi dau do chfnh xac ±0,1"C Thiet bj phai dflpc kiem tra hieu chuan
fiiem do, sd Ifldng dau do, lien ket dau do vdi cdt thep tuan thu phflong an cdng nghe thi cdng
fiau do phii cd dinh chac chan, dflpc bao ve, va each nhiet tuyet ddi vdi edt thep
Cac dau do nhiet dp be mat va d day khdi be tdng dflpc lap each mep ngoai eua khdi 100mm
Kiem tra de dam bao thdng mach va khdng cd dau do nao bi hdng
Xac nhan PA cdng nghe thi cdng va thiet ke cap phdi (2 cap phdi cho 2 Idp be tdng cung cfldng dp, mflc dp tda nhiet khac nhau)
Lfla chpn tram trdn, xac nhan xuat xfl, chung loai vat lieu, phu gia
Chat IflOng vfla be tdng dap flng [6,8,9] va cac tieu chuan khac phu hpp
Nhiet dp cua vfla be tdng tnrde khi do vao ket cau khdng dfloc vflpt qua 30"C, tdt nhat trong khoang 20-f25"C
Kiem tra tfnh thi cdng eua vfla va cfldng dp be tdng
Chap nhan ke hoach van chuyen: thdi gian, cfldng dp van chuyen, so Iflpng xe van chuyen, phan ludng giao thdng Kiem tra sfl phu hpp ke hoach van chuyen va nang suat dd be tdng tfnh den eac yeu td edng nghe: chieu cao Idp do, edng suat do be tdng, thdl gian hoan thanh mpt Idp dd, thdi gian bat dau ninh ket cua be tdng
Van chuyen vfla be tdng tuan thu [6] va cae tieu chuan khac phu hdp
Kiem tra dp sut tuan thu theo [4] va cac tieu chuan khac phu hop
fiuc mau thi nghiem tuan thij theo [5] va cac t/e khac phu hpp
Xac nhan phflong an bom be tdng: chung loai, sd Ifldng, cdng suat, vi tri bom Cd the ket hpp may bPm tinh va may bdm dtd
Lap dat he thdng dfldng dng bdm (lien ket, neo gifl chac chan, neu di tren cdt thep can I3p dat cac dung cu giim chan ddng nhfl eac ban ke bang cao su) Kiem tra, nghiem thu
Bdm be tdng lien tue, khdng dflng qua 1 - 2 gid tranh tac dng, tuan thd theo [6] va cac tieu chuan khae phu hpp
Trong thfli tiet nang ndng, mat ngoai dng can che phu de ban che bdc xa mat trdi lam ndng vua lam cho dp Iflu ddng cua vfla giam nhanh
Ky thuat do be tdng theo phfldng an cdng nghe thi cdng dflde phe duyet, tuan thu (6,8,9) va cac tieu chuan khac phu hdp
flam be tdng tuan thu [6] va eae tieu chuan khae phu hpp
Kiem tra chat lflpng be tdng, vi tri cdt thep, cae dau do nhiet dp va tinh trang van khudn trong sudt qua trinh do be tdng
Xac nhan phflong an bao dfldng be tdng
Xac nhan chung loai, chat Iflpng vat lieu gidnhiet, che phu
Hoan thien be mat be tong ngay sau khi ket thuc cdng tac do be tdng bang may xoa mat be tdng
Bao dfldng giflnhiet cho khdi be tdng, han che AT gifla tam va be mat khdi theo [8,9] va eae tieu chuan khac phu hdp Che be mat thoang cia khdi bang cac Idp vat lieu ket hpp: Idp 1 (Idp dfldi) - Idp vinyl; Idp 2 (Idp gifla) - Idp vat lieu gifl nhiet; Idp 3 (Idp tren) - Idp vat lieu each am nhfl mang nilon
Can cd ket qua do nhiet dp de dieu ehinh che dp va quyet Smh thdi gian bao dfldng:
-1- Trang thai phat trien va can bang nhiet (1-10 ngay dau): kiem tra nhiet do Idn nhat va kiem soat AT gifla tam va be mat khdi ludn thap hPn 25°C fiieu chinh tang nhiet dp bio dfldng bang mpt Idp nilon bd sung
-1- Kiem tra nhiet dp d bien va gdc khdi, neu nhiet dp giam manh (<50"C) bpc bo sung mdt Idp nilon
+Trang thai can bang va suy giam nhiet (7-9 ngay tiep theo): tiep tuc kiem tra chat che nhiet dp va tinh toan chi so ndt
de dieu chinh che dp bao dfldng
+Trang thai suy giam nhiet: (1-2 ngay tiep theo): kiem soat AT gifla tam va be mat khdi thap hon 28"C
Thdi gian bao dfldng dfldc quyet dmh bdi ky sfl phu trach, can cutsd lieu ve nhiet do, ket qua tinh toan flng suit va chi sd nflt cua be tdng Ve nguyen tac, bao dfldng den luc nhiet dp suy giam, chenh lech nhiet dp d mdc an toan khdng gay nflt cho ket cau
Cdng tac thao ddsau khi ket thuc thdi gian bao dudng be tdng
Ky thuat thao van khudn thflc hien theo quy djnh trong [6]
Thao dd dam bao be mat be tdng khdng hi xung nhiet do tiep xue dot ngdt vdi khdng khi ben ngoai
01.2014 SDnnisx 95
Trang 6cdng ty Lptte E&C Sir phan chia 2 Idp cap phdi
be tdng khac nhau nhu d hinh 4 va b i n g 1
Nhidt dp be tdng dupe xac dinh d 3 vj tri: trung
tam khdi do, d canh bien va d gdc (cie mep khdi
100 mm) Tai mdi vi tri cac dau do duge bd trf d
6 diem theo chieu cao ciia khdi: 2 vj tri d hai Idp
day va Idp b l mat, 4 vj trf 6 eac Idp phia trong
eiia khdi Ddng thdi xac djnh nhiet dp giufa be
mat be tdng va Idp vat lieu b i o dUdng va nhiet
dp khdng khu Do be tdng khdi mau dupc chia
ra lam hai lan theo chieu cao: 2200 mm va 3500
mm K i t q u i do nhidt dp d tam va Idp phfa tren
be mat be tdng t h i hidn d b i n g 2
Nhu vay, chenh lech nhiet dp giiJa trung
tam khdi va Idp be mat d ta't ca eae vj trf deu
trong pham vi eho phep Ngoai ra theo k i t q u i
tinh toan, chi sd ndt ddi vdi 4 trudng hgp dng
vdi nhiet dp vufa be tdng ban dau (300C, 350C)
va nhiet dp b i o dudng be tdng tuong dng
(300C, 350C) dat gia trj nhd nhat la 0,92 va gia
trj Idn nhat la 1,06 la chap nhan dupe, d i m b i o
be tdng khdng bi nift trong q u i trinh ddng ran
[12]
3.2 Quy trinh cong nghe va chi ddn bien
phdp, ky thugt thi cong
Trdn k i t qua nghien cdu ly t h u y l t , co sd
khoa hpc va sd lieu t h i nghidm, thilc te thi cdng,
qui trinh cdng nghe cP b i n thi cdng dai mdng
be tdng khdi Idn bang phuong p h i p do be tdng
lien tuc ket hgp phan chia Idp do vdi cap phdi
va sU tda nhiet khac nhau Suae tdng hpp va de
xuat d dang so do khoi d hinh 5 Npi dung ehi
dan bidn phap, ky thuat thi edng eo ban the
hien d b i n g 3
4 Ket luan
Cdng nghe thi edng dai mdng khoi Idn
do do bd tdng lidn tuc ket hpp phan chia Idp
do la edng nghd mdi, phu hpp vdi nhufng dai
mdng eo c h i l u cao va khdi tieh rat Idn Lfu diem
ndi trdi ciia nd t h i hidn d k h i nang k i l m soat
trudng nhiet dp va dng suat trong Idng khdi
bd tdng d mdc pham vi eho phep, d i m b i o bd
tdng khdng bj ndt do dng suat nhiet trong qua
trinh ddng ran Trong qua trinh b i o dudng ed
the chii ddng dieu chinh nhiet dp b i p duflng be
tdng de g i i m ehdnh lech AT gida eac Idp trung
tam va Idp be mat khdi thdng qua viec thay ddi
chi't lupng va sd lugng cic Idp phii gid nhidt
Ngoai ra, cdng nghe nay cho phep td chdc
q u i trinh dd be tdng lien tuc, khdng gian doan,
khdng p h i i t d chdc mach ngdng theo phuong
ddng va phuong ngang true dai mdng, do do
ket eau dai mdng d i m b i o k h i n i n g chju lUe,
cd tinh toan khdi v i chdng tham eao Vide do
bd tdng lidn tuc lam tang sil linh hoat trong
phuong thdc t d chdc thi cdng, chii dpng trong
bd trf thfet bj may mdc, nhan lue va vat lieu, day
nhanh dupc t i l n dp thi cdng
Tuy nhien, cdng nghd thi cdng nay ddi hdi
chi phi Idn cho cdng tac ehui'n bj, cdng nghe
be tdng hidn dai, trinh dp tp chdc va q u i n ly
chfnh x i c phuc vu thiet ke phuong an cdng nghe - t d chdc thi cong bat bupc p h i i tien hanh thf nghiem hien trudng tren khdi mau bd tdng tuong dng vdi dai mdng thuc te vdi cae t h i l t bj
do va phan mem tinh toan phii hgp Day dang
la nhdng van de khd khan ddi vdi cac phdng thf nghiem va nha thau xay dung trong nudc
De cd the lam chil va dng dung hieu qua cong nghd trong thi cdng cae ket cau be tdng khdi Idn va sieu ldn trong d i l u kien Vidt Nam, eac vien, trudng, cP sd nghidn cdu can ehu trpng dau t u (ed the hgp t i c vdi eac chuyen gia, don
vj nude ngoai ed kinh nghidm) de nghien cdu
d mdc dp qui md hon, dac biet la eac phuong phap, md hinh thf nghiem va tinh toan sd lieu,
t d d d thie't ke bien p h i p cdng nghe - t d chdc thi cdng phil hpp va hieu q u i
T A I L I E U THAM KHAO
1 Nguyen Tien flieh (2010), Cdng tac be tdng trong dieu kien khf hau ndng am Viet Nam, NXB Xay dflng, Ha Npi
2 Ho Ngpc Khoa, Nguyen Hung Cfldng (2011), "Lfla chpn
phfldng phap bk dfldng be tdng hieu qua trang dieu kien khi
hau ndng am" Tap chi KHCN Xay dung, fiai hpc Xay dflng, sd 9
3 Hd Ngpc Khoa, Vu Chi Cdng (2012), "Phan tieh trfldng nhiet do va flng suat nhiet trang be tdng khdi Idn bang phflflng phap phantfl hflu han'JapchlKHCN Xay dimg, fiai hpc Xay dflng, sdl4
4 TCVN 3106:1993, Hon hop be tdng nang - Phfldng phap thddp sut, NXB Xay dung, Hil Npi
5 TCVN 3105:1993, Hon hpp be tdng nang va be tdng
nang- Lay mau, che tao va bao dfldng mau thil, NXB Xay dung
Ha Npi
6 TCVN 4453:1995, Ket cau be tdng va be tdng cdt thep toan khdi - Quy pham thi cdng va nghiem thu, NXB Xay dflng
Ha Npi
7 TCVN 8163:2009, Thep cdt be tdng - Mdi ndi bang dng ren, NXB Xay dflng, Ha Npi
8 TCXDVN 305:2004, Be tong khdi Idn - Quy pham thi cdng
va nghiem thu, NXB Xay dflng, Ha Ndi
9 TCXDVN 313:2004, Ke't cau be tdng va be tdng cdt thep -Hfldng dan ky thuat phdng chdng ndt dfldi tac ddng cua khi hau ndng am, NXB Xay dflng, Ha Ndi
10 JCI, VCA (2011), Hfldng dan kiem soat nflt trong be tdng khdi Idn - phien ban 2008, VCA, Ha Ndi
11 ACI 207.1R-96, Mass concrete
12 Kim Kwang Ki, Hwang In Gwan, Kim Myoung Gug (2012), "Adiabatic temperature rise and reaction rate of mass structure in Lotte Center Hanoi project", Tap chf KHCN xay dflng, Vien KHCN Xay dflng, s o l
13 BaxeHOB K).M (2003), TexHonorMn deiona ACB, 2003, MocKBa
14 KonwjiOB B.fl., HryeH Kyu Rm, Xo HroK Kxoa (2012),
"UnaiwecKne npopeccbi, nporenaiomMe » TBepneioureM B mapKOM Knnmare deroHe", llpoMbiuineHHoe « rpaxcflaHCKoe CTponTenbCTBO, N' 5, MocKBa
15 MnpoHOB C.A., MariHHCKMii E.H (1985), OCBOBW
TexHonorHK deroHa B yenoBMSx cyxoro KimMara, Ctfoimium,
MocKBa
96|Binnii[i9ii 01.2014
Trang 7Phan tich cac mo hinh quan li ap dung cho doanh nghiep nganh Xay dyng
Ngay nhan bai: 28/11/2013
Ngay sil^a bai: 9/12/2013
Ngay cinap nlian dang: 18/12/2013
Le Anh Dung, Dinh Tuan Hai
T O M TAT:
Bai bao nay gicji thieu bon loai mo hinh
quan ly hay ap diang trong doanh nghiep
nganh xay dUng la To chufc trde tuyen To
chdc chdc nang, To chdc trilc tuyen chdc
nang va To chiJc theo dd an JVIoi loai
td chiJc dd'u CO cac tiu diem va han che
rieng, dong thdi co kha nang ap dung vao
cac doanh nghiep cu the, cac dieu kien
thdc te rieng
ABSTRACT
Le Anh Dung - Tnidng Dai hoc Kien
True Ha Npi
Dinh T\jSn Hal - Tnidng Dai hoc Kien
Tnic Ha Noi
1 Gidi thieu chung
Co cau t d chdc la mdt he thdng eac mdi quan he hoat dpng chfnh thdc bao gdm nhdng cdng viec ridng re cung nhu nhdng cdng vide
t i p the va su phan chia edng vide thanh nhdng phan vide eu the de x i c djnh xem ai lam nhdng vide gl va su ket hgp eac cdng vide ridng re vdi nhau ehi rd chp mpi ngudi thay duge hg p h i i lam vide cirng vdi nhau n h u the nap Cae thanh phan CO b i n eiia eo cau to chdc doanh nghidp:
- Chuyen mdn hoa: la qua trinh nhan didn
c i c cdng vide eu the va phan cdng eae ca nhan,
c i c nhdm da duge huan luyen thfch hgp de
d i m nhan
- Tieu chuan hoa: la qua trinh cu the hoa cic thil tuc cOa doanh nghidp ma theo do c i c
n h i n vidn cd thd' hoan thanh edng vide ciia hg theo mgt cich thdc thdng nhat la thfch hgp
Cic tieu chuan chp phep eae nha q u i n ly dp ludng thanh tfch cua nhan vidn ddng thdi cimg vdi b i n md t i cdng vide la eo sd de tuyen chpn
n h i n vidn cua tp chdc
- SU phdi hgp: l i nhOng thii tuc chfnh thdc
va phi chfnh thdc de lien ket nhdng hoat ddng ridng rd ciia doanh nghiep
- Quyen lUc: phan quyen va uy quyen
Do ed nhieu dang doanh nghidp tham gia vao d u i n xay dung (nhu chir dau tu, t u van, nha thau chfnh va nha thau phu) ndn cic mdi lien he hgp dong gida cac dpi tac se xuat hidn
va sd phu thudc v i o tdng kieu co cau to chdc cho cac d u an x i y dung ma chii dau tU se lua chpn de dat duge tdt nhat muc dfeh la cd dugc cdng trinh xay dung hay s i n pham hay djch vu hoan chfnh Cung can ghj nhd r i n g co cau td chdc va cac mdi lien he hgp ddng l i linh ddng
va can p h i i thay ddi, chfnh sda cho phu hgp vdi tinh hinh thUe te Them nda thi moi loai co cau
t d chdc cirng vdi tdng mdi lidn he hpp ddng se
cd t i e dung vdi mpt sd dUan va dieu kien thuc
te chd chung khdng the i p dung tdt, hidu q u i cho tat c i mpi loai hinh trong nganh x i y dung
Chfnh vl vay vide p h i n tfch eac co eau to chdc
dang ap dung eho cic doanh nghfdp nganh
x i y dung la can thiet de chi ra dupc k h i n i n g dng dung cu the ciia tdng Ipai trong thUc te x i y dung tai Viet Nam
2 Tong quan
2.1 Quin ly dUin ddu tUxiy dung
Q u i n ly ndi chung la su t i e ddng cd muc dich ciia chil the q u i n ly vao cie ddi tugng
q u i n ly de dieu khien ddi tUgng nham dat dugc mue tieu de ra Q u i n ly dau tU chfnh la su t i e ddng lidn tuc, ed td chdc, ed djnh hUdng q u i trinh dau tU (bao gdm edng tac chuan bj dau tU, thue hidn dau tUva van hanh ket qua dau tU cho den khi thanh ly tai sin do dau tU tap ra) b i n g mpt he thdng ddng bp cac bidn phap nham dat dupe hien q u i kinh te xa hdi cao trong dieu kien
cu the x i c dinh va tren co sd van dung s i n g tao nhdng quy l u i t kinh te k h i c h quan ndi chung
va quy l u i t van ddng d i e thir ciia dau t u ndi ridng Q u i n ly d u i n la viec i p dung nhdng hieu biet, ky nang, edng eu, ky thuat vao hoat ddng dU i n nham dat duge nhdng ydu cau va mong mudn tir dU i n Q u i n ly dU i n cdn la qua trinh lap ke hoach tdng thd', dieu phdi thdi gian, nguon lUc va giam sat qua trinh p h i t trien cua
d u i n t d khi bat dau den khi ket thuc n h i m d i m
b i o cho d u an hoan thanh dung thdi han, trong pham vi n g i n sach dUge duydt va dat dUpe c i c yeu c i u d i djnh ve ky thuat va chat lugng s i n pham djch vu, bang nhdng phUOng phap va dieu kien tdt nhat cho phep
Q u i n ly d u a n bao gdm 3 giai doan chii yeu:
- L i p ke hoach: D i y la glal doan xay dung muc tidu, xac djnh nhdng cdng viec can dupe hoan t h i n h , ngudn lUc can thiet de thuc hidn
d u i n va la q u i trtnh phat trien mdt ke hpach hanh ddng theo trinh t u Idgic ma cd the bieu dien dugc dudi dang so do he thdng
- Dieu phdi thuc hien dU i n : D i y la q u i trinh p h i n phdi ngudn lue bao gdm tien vdn, lao dpng, thiet bj va d i e biet quan trpng l i dieu phdi va quan ly tien dp thdi gian
- G i i m sat: La q u i trinh theo ddi kiem tra
01.2014 Bwniiax 97
Trang 8quan va thUc hidn b i p eao hien trang
2.2 Lita chgn cacdu tS chiic thich hgp
Moi doanh nghiep deu ed d i e trung rieng biet, dupe tien hanh trpng
h o i n c i n h , mdi trudng eu the v i dugc thuc hidn bdi cac t d chiTe khic
nhau D i y la eae yeu t d ehinh can chii y p h i n tfch de giiip chiing ta chpn
dugc cau true to chdc phii hgp vdi doanh nghidp nganh x i y dung Trong
dieu kidn hidn nay, khi ma yeu cau ve viec thich dng vdi sU bien ddng
nhanh ciia thj trudng, sU thay ddi eiia cic yeu t d kinh te xa hpi cung nhu
sU p h i t trien khpa hpc ky thuat, co cau chdc q u i n ly thUc hien d u an dau
t u x i y dung can p h i i duge x i y dung sao cho mdi quan he giufa cic hoat
ddng l i tdt nhat de' dat dugc muc tieu eiia d u i n v i cd k h i nang p h i n dng
nhanh nhat vdi nhdng thay doi vd mdi trudng dU i n
Trudc khi quyet djnh lUa chgn cP cau tp chdc q u i n ly doanh nghiep,
can tien h i n h p h i n tfch d i e df^m nganh x i y dung mpt cich ky ludng, t i p
trung vao c i c diem chfnh nhu sau:
- Sin pham (chuyen giao, hang muc cudi cirng) ciia doanh nghiep
xay dung
- Muc tieu: thdi gian, ehi phf, muc tieu thUc hidn de dat dugc sin
phi'm (chuyen giao) cua doanh nghidp xay dung
- Muc tidu khic: ben canh muc tidu chfnh cua doanh nghiep x i y dung
cd the cd muc tidu khic nhu p h i t trien k h i nang ke hoach h p i cOa t d
chdc, p h i t trien hd thong mdi
- Ljch trinh (khoing thdi gian can thiet de thUc hien)
- Mdc dp phdc tap (doi hdi ve ky t h u i t )
- Op Idn v i b i n chat ciia nhiem vu can tien h i n h
- Ngudn lue: con ngudi va kinh phf
- Co cau t d chdc hfdn taf cua co quan dugc gfao nhfem vu q u i n ly d u
an
- He thdng kiem soit va thdng tin
Cic cau hdi ho trp cd the sd dung de phan tich d i e diem eiia dU i n
trpng q u i trinh xay dung co c i u to chdc bao gdm:
-Td chdc cua eg quan dugc giao nhiem vu q u i n ly dU an da san sing
cho cdng t i c q u i n ly d u i n dau tuxay dung chua?
- Co quan chii quan d i tdng thuc hidn thanh edng dU i n dau tU x i y
dung nao chua? Hidn tai cd bao nhidu d U i n ? Loai nao?
- DU i n dau t u xay dirng can thUe hien cd Idn khdng?
- Mdc dp phdc tap eiia d U i n d i u t U x i y dung dugc giao?
- D U i n d i u tuxay dung can thirc hien cd quan trgng, cd y nghia nhu
the nao ddi vdi su hung thjnh, tdn tai cua eo quan dupc giao nhiem vu
q u i n ly?
- L i n h dao coquan chu q u i n mong mudn dieu gl? Mdc dp chap n h i n
trong vide thay doi co cau t d chdc hien ed ciia co quan?
3 Phan tich cac co cau to chiirc pho bien trong doanh nghiep
nganh xay diing
3.1 Ccr cau to chute true tuyen
- Nguydn t i e : bp m i y q u i n ly thep kieu true tuyen duge td chdc sao
cho c i c tuyen quyen luc trong doanh nghidp l i dudng t h i n g Moi cap
diidi chf chju s u q u i n ly cOa mdt cap tren duy nhat v i thudng duge ggi l i
che dp mpt thil tradng
- Uu diem: don g i i n , dat dupc su thdng nhat tuyet ddi trong menh
Idnh De d i n g quy t r i c h nhidm khi edsai sdt, suvu xay ra ddng thdi edthe
khen thudng kjp thdi vdi ngUdi ed cdng, cd t h i n h tich tdt
- Nhugc diem: t i p trung g i n h n i n g v i p ngudi q u i n ly cap cao, doi
hdi hp p h i i hieu biet s i u rpng ve cic mat chuydn mdn khac nhau Ddng
thdi khi quy md doanh nghidp t i n g Idn vdi sd lugng eic bd phan true
thudc nhieu thi ngUdi q u i n ly cap cao se rat khd kiem soat dugc toan bd
cdng vide
- Cfng dung: i p dung phu hgp vdi cic doanh nghidp cd quy md hoat
ddng don g i i n v i cd it s i n pham Vi mdt ngudi q u i n ly cap tren cd the
hieu rd rang nhdng hoat dgng ciia cap dudi m i khdng can phai thdng
qua c i c co quan chdc nang hoac c i c bd phan giup viec nao
Tdng giim d6c
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So Jo CO cau td chiic true tuyen cua mpt tong cong ty
3.2 Ca cau tochUc theo kieu chUc ning
- Nguyen t i c : tdng giam ddc la ngUdi q u i n ly chung cdn ve mat
chuydn mdn thi giao cho cac phdng ban chuydn mdn phu t r i c h cie ITnh vue eu the De g i i m bdt g i n h nang cho ngUdi q u i n ly cap cao, ngudi ta
td chdc ra c i c bd p h i n chdc n i n g (hay cdn gpi l i cic phdng chdc ning),
c i e bd phan nay true tiep ra quyet djnh xudng cac bp p h i n true thupc chuydn mdn eua minh
- Lfu diem: p h i n anh mpt each hgp ly c i c chdc n i n g vdi c i c nhidm
vu dugc phan djnh rd r i n g , t u i n theo c i c nguydn t i c chuyen mdn hoa nganh nghe, p h i t huy sdc manh va k h i nang ciia dpi ngu c i n bd theo tdng chdc n i n g , g i i m chi phi va rut ngan thdl gian d i p tao, tao ra cic bidn
p h i p kiem tra chat chd ciia cap trdn cao nhat
- Nhugc diem: c i n bg q u i n ly cap dUdl nhan nhidm vu, menh Idnh tir nhdng phdng ban chdc n i n g k h i c nhau ndn cd the khdng cd su thdng nhat gida c i e quyet djnh Nhieu khi cac nhidm vu, menh Idnh cd the miu thuan nhau, gay khd khan cho cap thda hanh va gap nhi^u khd k h i n khi can cd sU phdi hgp gida eic phdng ban chdc n i n g Cic phdng ban chufc nang cd the diin day trach nhiem cho nhau neu cd sai lam, sUvu xay ra
- Ung dung: ap dung cho c i c doanh nghiep cd d i e t h i i cao, khi hoat ddng gida cac bd p h i n tuong ddi dpc lap (nhu ngan hang, b i p hiem, du Ijch va chdng khoin)
So do CO cau to chiic theo chile nang cua mpt tong cong ty
3.3 Ca cdu to chUc theo kieu true tuyen chute ning
- Nguydn t i c : eac md hinh t d chdc theo true tuyen va chdc n i n g co
nhieu Uu diem k h i c nhau c i c n h i q u i n lyda xac djnh cocau t d chdc theo kieu true tuyen - chdc nang de ap dung cho edng ty minh Trong eo cau nay thi quan he true tuyen t d tren xuong van tdn tai nhdng de giiip ngirdl
q u i n ly cap eao dUa ra cae quyet djnh dung dan thi c i c bd p h i n chiic
n i n g giiip viec trong nhdng linh vuc tai ehfnh, ke t o i n , nhan sU, Nhdng
bd phan chdc nay khdng true tiep ra quyet djnh xudng eic bp phan true thudc ma ehi lam nhiem vu tham muu cho nha q u i n ly cap cao trong vide ban hanh v i thUe hidn cac quy djnh thudc pham vl chuydn mdn n g i n h Trong mdt sd trudng hgp neu khi nhan dupc su u;/ quyen ciia ngirdi
l i n h dao cap cao thi c i c bd p h i n chdc nang nay cd the true tiep dUa ra
c i c quyet djnh cu the
- Liu diem: dat dugc tinh thdng nhat trpng menh lenh N i n g cap cic quy djnh q u i n ly, g i i m bdt g i n h nang cho ngudi q u i n ly cap cao cung
n h u quy djnh t r i c h nhiem rdrang
- Nhugc diem: mudn cOcau p h i t huy dugc t i c dung tdt thi p h i l chii y nhieu trong giai doan x i y dung cocau Khi thiet ke nhidm vu cho moi bd phan chdc n i n g thi ngirdl q u i n ly cap cao p h i i chi ra nhidm vu eiia mo'i
bd phan nay p h i i thUe hidn cung n h u mdi quan he ve nhiem vi- giija cac
bd phan chdc n i n g vdi nhau n h i m t r i n h su ehdng cheo trong g ^j^
Qasammasi 01.2014
Trang 9phin chdc nang phii true tiep chi dao cic bd phin true thudc trong qui
trinh thuc hien cic ke hoach thupc pham vi chuyen mdn cua minh
- Ling dung: diy la co ciu td chdc phd bien nhit trong eic tdng edng
ty d Viet Nam hien nay
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So do CO cau to ehijc theo true tuyen diiie nang ciia mot tdng cong ty
3.4 cacau tochUc theo kilu dudn
- Nguyen tac: Ddi vdi mpt sd doanh nghiep die thii cao, cd nhieu loai
sin pham gidng nhau v i moi loai sin pham cd gii trj Idn hoac dugc td
chdc sin xuat tai nhieu dja phuong khic nhau thi ngudi ta td chdc theo
kieu du in Trong moi dU i n thi tuy theo quy md cd the to chdc tiep theo
kieu true tuyen hay true tuyen chdc nang
- Uu diem: diy l i sU phit trien ciia co cau to chdc theo kieu true tuyen
vi true tuyen chdc ning Can luu y trong moi dU i n co cau to chdc quin
ly ch! tdn tai ciing thdi gian dU in, khi xong dU i n thi co cau td chdc dU i n
cung ket thuc.Tlieo co cau nay thi mdt ngUdl cd the ddng thdi tham gia
nhieu du i n khic nhau
- Nhugc diem: khdng tich luy dirge kinh nghidm do co eau niy se giii
the sau khi hoin thinh dii in Nhan vidn tham gia ca ciu nay cung bien
ddi, khdng 6n djnh
- Ung dung: diing cho cic dU i n xiy dung, hii ngoai hay cie khu vuc
xa cich vdi van phdng chfnh eda cdng ty
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So do CO eau to chile theo dp an cOa mpt tong cong ty
4 Ket luan kien nghj
Co cau td chdc la mdt he thdng ehfnh thdc, giup cac bd phan, cic
phdng ban trong doanh nghiep cd ket, lidn he vdi nhau Vdi co cau td
chdc tdt se giup cho doanh nghidp boat ddng hidu qui hon vdi cic thdng
tin dugc truydn t i i qua he thdng chinh thdc cda doanh nghidp, ddng thdi
mpi ngudi, mpi bd phin se hi^u dugc trich nhidm va quyen hinh cu the
eOa ho Bai bio nay gidi thidu bdn loai cO eau td chdc hay ap dung trong
doanh nghidp la Co cau td chdc tnic tuyen, Co cau td chdc chdc nang, Co
ciu td chdc tnic tuyen chdc ning v i Co cau to chdc theo du in Mdi loai
CO cau to chdc deu cd cie Uu diem va han che ridng, ddng thdi cd khi
ning i p dung vio cic doanh nghiep cu the, cic dieu kien thUe te rieng
Trong trudng hgp thue te, cac nhi quin ly doanh nghidp can hieu ky ve
cic CO ciu td chdc nay nhim muc dich i p dung chung cho phii hgp vdi
dieu kidn eiia doanh nghidp de mang lai hieu qui quin I)? tdt nhit
TAlLlfUTHAMKHAO
1 Le Anh Dung (2009), Glao trinh Lap ke hoach va Qujn ly dpan dau tiTxay dimg,TrUcing dai
hpc Kien true Ha Npi
2 Sinh Tuan Hii va Pham Xuan Anh (2013), Quin ly dir an trong giai doan xay dung, Uhh xuat
Mn xay dilng, Ha NoL
3 Binh Tuan Hii (2012), Bai giing "Phan tfch eac mo hinh trong quSn iy" cho dio tao cao hpc
chuyen nginh eong nghe va quin ly xay dimg, Tnidng dai hpc Thiiy Loi, Ha Npi
4 Binh Tuan Hii (2012), Bai giing "Quan ly doanh nghiep" cho dio tao dai hpc chuyen nganh
puin ly do ' " ' a cong trinh, TnlSng dai hoc Kien tnic Hi Npi
01.2014 nnniipBi 9 9