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Bao tri ket cau be tong cot thep nha sieu cao tang CP Viet Nam
Ngay nhan bai: 23/8/2014 Ngay su:3 bai: 5/9/2014 Ngay chap nhan dang: 10/9/2014
TOM TAT:
Trong nhflng nam gin dly, nha sieu cao ting dfldc xay dflng va dfla vao khai thac ngay cang nhieu d Viet Nam. Tren thflc te, cdng tac bao tri toa nha trong do cd bao tri he ket cau chiu Iflc cdn mdi m^
doi vdi cac ky sfl phu trach van hanh khai thac nha siSu cao tang.
Do do, viec nghien cflu de xuSt mot quy trinh bao tri cho ket clu be tdng cot thep (BTCT) chiu Iflc nha sieu cao tang la c5n thiet. Bai bao the hien ket qua phan tich tong quan co sd phap ly, khoa hpc va thflc tiln CO hen quan den vin de bao tri ket cau BTCT nha sieu cao ting, tfl do de xuat quy trinh bao tri co ban de ap dung thflc hien cho nha sieu cao ting d Viet Nam.
Tfl khoa: nha sieu cao tang, ket cau be tdng cot thep, bao tri, quy trinh bao tri, bao tri ket cau hi tong cot thep.
ABSTRACT
In recent years, numerous super high-rise buildings have been built and put into operation in Vietnam In fact, building maintenance, particularly maintenance of load-be a ring structures, is still a newly concept to engineers who are responsible for operating super high-rise buddings. Therefore, it is vitally important to study and propose a procedure for maintaining reinforced concrete load-bearing structures of super high-rise buildings. I h e paper presents the comprehensive results of analyzing legal, scientific, and practical basis regarding maintenance problems of reinforced concrete load-bearing structures, accordingly propose a basic maintenance procedure that could be applied for super high-rise buOding in Vietnam.
Keywords: Super high-rise buildings, reinforced concrete structure, maintenance, maintenance procedure, reinforced concrete structure maintenance.
TS. Ho Ngoc Khoa TS. Tran Hong Hai
Khoa XD DD&CN, Dai hoc Xay dflng Email: [email protected]
Ho Ngoc Khoa, Tran Hong Hai
IVld dau:
He ket cau BTCT nha sieu cao t i n g 6 Viet Nam bao g6m c^c Ic^ cau ehiu luc dflng (161, vach, cot) ket hop vdi eae ket cau chiu lUe nam ngang (dam, san) va cac he giang cflng (tang cflng, giang). Trong qua trinh sil dung dudi sUtae d6ng eiia tai trgng va eac yeu to bat lOi cua khi hau dan den chat iuong va cong nang sfl dung cua ket cau BTCTd^n bj xuong c^p theo thdi gian. Do tam quan trong va tinh thong nhat eiJa he ket cau, cac ket c^u BTCT nha sieu cao tang gan nhU khdng the thay the. NhUvay, vilje xay dung qui trinh bao tri tr^n eosd ke hoach chien lUOc bSo tri, lam can cfl trien khai cdng tac bao tri theo dilng qui trinh chuan, de cao viee kiem soat tflng hU hdng nh6 trUde khi nd phat t n l n nghiem trong vdi ket cSti BTCT nha sieu eao tang la rat quan trong.
1, Dac diem h& ket cau BTCT chiu Iflc nha sieu cao tang IsViet Nam Nha sieu eao tang la c6ng trinh phflc hop da chflc nang- trung tam thUcJng mat. van phong, khach san, can hocaocap.Vat iieucOb^ndUOc sfl dung de xay dUng khung chju Iflc cCia nha sieu eao t^ng la thep, lien hop thep - be tong va be tong cot thep. C^c toa nha sieu eao tang deu CO kien true dang thap vdi chieu cao rat idn. Hien nay chua co mot tieu chf nhat quan ve chieu cao cua nha sieu cao t^ng, fl nUdc ta chap nh^n khai niem tUong doi ia nha sieu cao tang la nhflng cong trinh c6 s6 tang khong nho hon 40. Ve hinh khdi nha sieu cao tang thudng dUoc bo tri vi^
3 khong gian kh6i doc lap: phan tang ham [basement), khoi de thap ting (podium)vaphanthapsieueaotang, lien ket vdi nhau bdi he thong giaO thong dflng [8].
Thiet ke ket cau nha sieu eao tang dfla tren sU ket hop gifla hai hay
\ i M a u u m i f n i M B i M i i M s i H i K n uiciabfaiiKiraiir-MMiii
....iiHiiilllil ^^hi.
tllnlil. Slf thay dfiiviksil dung BTCT ttong xay dung liet d u nha sieu cao tang tren the giiil gil doan 196D-2003
nhieu he ket cau co ban: ket cau he khung dang ong, ket c^u ket h o p loi vi tang cflng (co thi ket hop dai tang); ket cau ket hop loi va tUdng chm Iflc; ket eau dng vfli giang d mat dflng; ket eau 6ng bo, ket eau ong trong ong; ket cJiu ing ket hop loi
Hg ket eau ioi bSng BTCT kit hop tang cflng bSng t h e p hoac hen hop thep - be t o n g duoc sfldung nhieu trong thfli gian gan day d chau A, CO the ke den toa nha Jin Mao Tower 6 Thuang Hai 88 tang, toa nha Trung tam tai chinh quoc te 2 IFC Hong Kong 88 t ^ n g va toa nha Trung tam t h u o n g mai quoc te ICC Hong Kong 110 tang, Cac toa nhS sieu cao tang d Viet Nam nhu Bitexco Financial Tower, Keangnam Hanoi Landmark Tower va Lotte Center Hanoi deu sfl dung h^ ket eSu loi ket hop tang cflng.
He ket eau loi ket hop t^ng eflng bao gom mgt loi chinh bang BTCT hoac khung giang bSng t h e p ket ndi vdi cdc cot ngoai bdi eae console ngang c6 d6 cflng uon Idn. De phat huy tdi da sfl can t r d cilia cac cot bien ddi vfli suxoay eua Ccic tang eflng, bo tri mot dam eao hoae vanh dai xung quanh kit cau d cao do ciia cae tang cflng. De lam eho eae tang eflng va dam vanh dai dCi cflng khi chiu uon thi chLing cd chieu eao it nhat la mot, hai va eo the la ba tang.
Hg thdng tang cflng nay rSt hieu qua trong viSc tang do cflng udn eOa ket eau nhutig no khong lam tang khS nang chiu c3t ma kha nang chiu eSt chCi yeu do loi ehiu.
2. V&t lieu BTCT sfl dung cho ket cau chju Iflc nh^ sieu cao tang
Cho den nay, nhieu nha sieu cao tang tren the gidi da dflflc xiy dflng tren nen teing k^t cau khung chiu Iflc la BTCT do tai cho, trong do CO Burj-Dubai Tower (Dubai - A Rap, Petronas Twin Tower (Malaixia); Bank of China Tower (Hong Kong); Jin (Wao Building (ThUOng Hai);
Texas Commerce Tower (IVly); Federasia Tower - Moscow City (LB Nga) va nhieu cong trinh khac.
Tinh t f l nam 1985, vi^c sfl dung BTCT trong xiy dung ket eau khung chiu Iflc cua nha sieu eao tang c6 sfl phat tnen ro net (hinh 1).
STCr sfl d u n g eho xay d f l n g nha sieu cao tSng phai la be t o n g chJit luong eao, ket hap nhieu t i n h ch^t vuot troi; t i n h thi cong, cudng dp, do ben s f l d y n g cao, chi so mai moi va tham thau thap, b^o ve an toan ddi vdi cot thep, vflng b^n trudc an m o n hda hoc va vi sinh, on djnh v^ the tieh.
Khi thiet ke phan ldi khung chju Iflc cua nha si&u cao tang, theo ehi^u eao cong trinh, cuimg d 6 be t d n g duoc lUa chon giSm dan 3i phu h o p vdi tiet dign c^t vach, gi^m trong luong ban t h a n ket cau vi giam thieu ehi phi.
VI d u cdng trinh Jin IMao Building cudng do bi t o n g ciia cac ket cau sieu edt (megaeolumn) vi t f l d n g vach 6 eac tang dudi t u o n g flng \i C80 va C60, g i i m den cac tSng trgn eiing 1^ C40; cong trinh Hanoi Landmark Tower cuimg do be t o n g loi vicb cfl^n va cot giam t f l C70 den C50, k^t
cau san giam t f l C50 den C35 theo chieu eao cong trinh [9].
Oe tan dung nhflng Uu diem eua be tong cudng dd cao, viee sfl dung cot t h e p cuflng d p eao {High strength steeL HPS) la can thiet [10]
Hien nay tren the gioi, eae nha cao tang va sieu cao tang thudng sfl dung cdt thep co cuflng dd t f l SO ksi (345 IVIPa) den 75 ksi (517 MPa) [11].
3. Cosd phdp ly va khoa hoc cdng tac bao tri ket ciiu BTCT nha sieu cao tSng d Viet Nam 3.1. Cdng tde bdo tri kit edu BTCT nhd sieu eao tdng trin the gidi
d eSc nude, khong cd tieu chuan hay qui dinh ngng cho cong tcic b^o tri he ket cau ndi chung va ket cau BTCT ndi neng cua nha sieu cao tang. NhOng nguyen tac ca b i n ve bia tri tai san va cac he t h d n g thiet bi ky thuat toa nha 6\sac qui dinh trong "2012 International Property Mametance Code" [12]. Tuy nhien, trong tai lieu nay, khong co ndi dung qui djnh v^ b^o tri eae bg phan ket cau cua tda nha.
Tieu chuan "BS EN 15331-2011: Criteria for design management and control of maintenance services for build" [13] dUa ra tieu chi va eae phuong phap chung, phuc vu qua trinh lap ke hoach, quan ly va kiem soat b i o tri toa nha va khu vUc ngoai vi theo eae quy dinh phap 1;^, phii hop muc dich ciia chii dau t u va ngUdi sfldung.Tieu chuan eung de cap den yeu cau chat luong ciia edng tae bao tri, lam ecf sd eho qua trinh quan ly bao tri cac toa nha. Theo tai iieu nay, tda nha la cong trinh xay dUng bao g d m cac bd phan bao che, chiu lUc, Idp hoan thien, he thong ky thuat va cac chi tiet, ket cau bgn ngoai tda nha. Bao tri nha la sfl ket hop eiia tat ci cac cdng tac ky thuat, hanh chinh va quan 1^ trong sudt vdng ddi toa nhS vdi muc dieh duy tri. hay sfla chfla lai de nd cd the dap flng chflc nang sfl dung theo yeu cau.
Cdng tac sfla chfla ket cau BTCT tda nha 6 chau Au dUae hudng dan trong trong "EN 1504: Products and Syetem for the protection and repair of concrete' [14]. Bd tieu chuan nay gdm 10 tigu chuan t f l EN 1504-1 den EN 1504- 10, qui d m h CO bein cae ngi dung lien quan den cdng tae khao sat danh gia, bao ve va sfla chfla ket eau bg tong cong trinh xay dung. Ngi dung tieu chuan de cap cac van de. yeu cau cdng tac chuan bj vat lieu va he thong sfla chfla ket cau;
ygu cau ky thuat ddi vfli vat lieu bao vg be mat va vat lieu, he t h d n g sfla chfla. gia cudng ket cau; ddi vdi chdng an m o n edt thep; qui dinh vigc kiem tra chat luong va luu hd so sfla chfla ket cau. Tai My, cac bg tigu chuan xay dung va b i o tri eiia eac bang n h u ' 2 0 1 0 Buiiding Code ofNewYorkState","2010 Property Maintenance Code of New York State", "2012 Virginia Uniform Statewide Building Code"{USBC),"2012 Virginia Maintenance Code" deu cd qui djnh co b i n ve b i o tri hg t h d n g ky thuat tda nha, tuy nhign lai khdng de cap den ngi dung bao tri cac bo phan ket eau vh kit cau BTCT.
Cdng tac bao tri tda nha d Lien bang Nga, Cong hoa Belariitxia dUOc qui dinh bdi tieu chu^n qudc gia ve vin h i n h ky thuat cdng trinh xay dung, trong do neu rd: b i o tri cong trinh xay dflng 1^ mot to h o p cac cdng vigc nhSm duy tri thdng sd thiet ke, t i n h trang \htn viee on djnh ciia ket cau, b d ph3n va he t h d n g ky thuat ciia cong trtnh [16,17]. Cdng t i c khao sat d^nh gia phuc vu b i o tri, sfla chfla ket c i u nha d Lien bang Nga duOe hudng dan bdi tigu chuan CP 13-102-2003: HUdng dan danh gia kgt cau ehiu Iflc nha v^ cong trinh [18] Cdng tae sfla chfla ket cau BTCT ciia edng trinh xay dUng d Nga hien nay cung duoe khuyen e^o ap dung tigu chuan EN 1504 eCia Chau Au.
Trong cac qude gia d Chau A, N h i t B i n da xay dflng dfloc tigu chu^n chi tiet ve b i o tri ket cau BTCT cong trinh xay dung: "JSCE Standard Specifications for Concrete Structures (2007) - Maintenance". Tieu chu^n nay de cap den c3e van de mang tinh nguyen t i c c o b i n eiia b i o tri ket cau BTCT, cac phuong phap xac dinh co che h u hdng cua kgt c i u , c i c loai hinh k i l m tra phuc vu b i o tri, e^e phuOng phdp b i o tri cho eac loai ket c i u BTCT kh^c nhau va each lap v^ lUu g i f l ho so b i o tri [15].
3.2. Ca sdphdp ly edng tde bdo tri kit cdu BTCT nhd si6u cao tdng d Viit Nam
Hien nay, he thdng van ban phap ly va tieu c h u i n xay dUng nUdc ta chUa cd quy dinh ve b i o tri nha Sieu cao tang Vi vay, trong thUc te phai van dung nhflng van bSn phdp 1^, tigu chuan, qui dinh vg bao tri cdng trinh dcin d u n g , nha d noi ehung ket hop vdi eae tigu c h u i n nude ngoai phu hop de thuc hign bao tri ddi vdi kgt eau BTCT nha sigu eao tang tai Vigt Nam.
Luat Xay dUng sd 16/2003/QHl 1 [1] neu ro, cdng trinh xay dung la t^i san dugc tao t h ^ n h t f l vat lieu xay dflng, t h i l t b| l i p dat Veio cdng trinh, duqc xay dung theo thiet ke. Chii sd hflu hoac ngudi quan ly sfl dung cong trinh co t r i c h nhiem b i o tri cdng trinh, may mdc, trang thiet bi cdng trinh. Viec t a o tri cong trinh xac dinh theo ioai v i c i p edng trinh va dflcfc qui dinh bdi Chinh phli.
Nghi dinh 114/2010/NO-CP ve bao t n cdng trinh xay dflng [2] dinh nghia: b i o tri edng trinh la tap hop cac cdng viee nham b i o d i m va duy tri sfl lam viec binh t h u d n g , an toan ciia edng trinh theo quy dinh cua thiet ke t r o n g suot q u i trinh khai thac sfl dung. Bao tri phai theo quy trinh dugc lap phu hdp vdi c i c bd phan, t h i l t bi lap dat vao cdng trinh. loai, cap cdng trinh.
dam b i o edng trinh van hanh lien tuc, an toan ve ngUdi va tai s i n . Ndi dung b i o tri edng trinh CO the bao gdm mdt. mdt sd hoac toan bo c i c cong viec sau: kiem tra, quan t r i e , k i l m dinh chat lugng, b i o d u d n g va sfla chfla cdng t r i n h .
Theo [2] quy trinh b i o tri cdng bao gdm c i c ndi dung sau: quy dinh cdc t h d n g sd ky t h u i t , cdng nghg, x f l ly k i t q u i quan t r i e khi cdng trinh cd ygu cau thuc hign quan t r i e ; quy d m h
MOC
ddi tflong, phuong p h i p va tan s u i t k i l m tra edng trinh; quy dinh ndi dung va chi dan thflc hien b i o dudng cdng trinh; xic dinh thdi diem, dfii tflong v i ndi dung c i n kiem d]nh djnh ky;
quy djnh thdi diem vi ehl dan thay the dinh ky cic thiet bi l i p dat v i o cdng trinh; chi d i n phUcmg ph^p sfla chfla c i c h f l hdng cfla cong trinh, xfl \j' cic trfldng hop cdng trinh bi xudng c i p , quy djnh cic dieu kign nham b i o dam an t o ^ n lao dgng, ve sinh mdi trUdng trong qua trinh thflc hien b i o tri cdng trinh.
Thdng t f l s6 02/2012/TT-BXD: "Hudng d i n m^t so ngi dung ve b i o tri edng trinh dan dung, cdng trinh cdng nghiep v^t lieu x i y dUng vi edng trinh ha t i n g ky t h u i t dd t h j " [3] quy djnh cic cdng trinh, bd p h i n cdng trinh b i t bude p h i i quan t r i e trong q u i trinh sfl dung; xfl ly ddi vdi cong trinh xuong cap ve c h i t lUong, khdng d i m b i o an todn khai thac; g i i i q u y l t sU cd trong qui trinh khai t h i c , sfl dung v i k i l m tra vigc thuc hign b i o tri cflng trinh.
3.3. Casdkhoa hgc edng tde bdo tri kit edu BTCT nhd sieu cao tdng A Wit Nam
Co sd khoa hoc vg b i o tri k i t c i u BTCT n h i sigu cao t i n g duoc lam ro t f l ket q u i phan tich, tdng hop Ccic tigu chuan eiia Viet Nam va nUdc ngodi tign quan d i n cdng nang v i tinh trang l i m Vlgc ciia k i t c i u ; tigu chuan vh cdc phUdng phdp kiem tra ddnh gid tinh trang k i t cau; hg thdng va phuong phap b i o tri, sfla chfla k i t c i u vd cdc v i n d l k h i c cd lign quan.
a) Cong ndng vd chl so cong ndng kit cdu BTCTcOa nhd vd cdng trinh
Theo "TCVN 9343:2012 Ket eau be t d n g vd bg tflng cdt t h ^ p - Hudng dan cdng t i c bdo t r i ' [4], cdng nang k i t cau l i k h i nang (hoac higu q u i ) ciia k i t c i u d i m nhdn ede chflc nang t h i l t k l eiia nd. Chi sd cdng nang Id chl sd d m h Ifldng ciia cdng nang k i t c i u . D d xudng c i p Id do suy g i i m cflng ndng hoae muc do xudng c i p cOa cdng trinh do eie tac ddng ciia mdi truimg ke t f l khi x i y dflng. D i u hieu xudng cap vd c i c t h d n g sd xudng cap cOa k i t cau c i n cd bign phap sfla chfla dflcfc x i c dinh qua cdng tde kiem tra k i t c i u . Cdng tde sfla chfla l i cdng vigc b i o tri dUdc thflc hign vdi mue dich ngan ngfla hodc l i m han c h l qud trinh xudng cap ciia k i t c i u , gifl vflng h o i c tang cUdng them cdng nang ciia no, hodc de g i i m nguy co gay hai eho ngudi sfl dung.
Ndi dung [4] quy dinh v l phan ioai b i o tri, cac nguygn t i c v i phUdng phdp thflc h i l n edng tde k i l m tra, ddnh g i i mflc d d h u hong d l phuc vu cflng t i e b i o tri, sfla chfla k i t cau BTCT. Nha sieu cao t i n g la cflng trinh cap dae biet va k i t cau BTCT ciia n d thudc foal b i o tri nhdm A.
Vi^c d i n h gid cong nang dflOe thflc hign t h d n g qua c i c chi sd cdng nang yeu c i u (P ), xde ^ n h theo cdc tieu chuan phii hc»p dfloc dp dung trong q u i trinh t h i l t ke, thi cdng cong trinh v i chi s6 cong n i n g thuc te ma k i t eau dat dfloc (P^, xde dinh theo thuc t l k i l m tra k i t cau hodc tinh t o i n . Tuy theo loai hinh va mflc
I Chlin lirtrc bit (Ung sjin cda cOng ty
Chinh sach qudn li^toan nhi
TMngsAdvA n 1 [ Chi*nlinj«xaydi/ng 1 [ MfthlnhquSniy 1 1 Ph4nTng i n khai Iti4c 1
Sv Srrii hirdng tdi h$
kit (Au vd cdng n3ng
(Nhfln li/c, tniftntio,
Ihi^bi
ih hinh thOc bio tri [ xacalnhd^ng ] [ l / d c luvng co ch4 1 I bao til j xu^g cdp
m kit c i u Iheo quyln ifu tl»n can UiMp
in tich chl pi
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Dv tfnh ngln sach
i
Quy4t djnh m(K chl phi
Ki hoach b ^ trf Ung th6 Ti6u chuin dp dyng Nhflm dfli luyng bdo tri ThCr tl/ LTU tiSn baa tri Hinh ^i>c vi thfri giaci bao tri NguAn lire b^o Iil Ngan s6ct) bSo bl Nha thiu vS hinh thi>c hpp afing bi Quitrlnhbaotrlcffban
ThvchienKHbaotrf j — J DO'lieuphinhii I ifinh 2. Trinh tir l|p he hoadi t)Jo tri tong the he 1(3 cau dim lire BTQ nha s i ^ cao ting
do h u hdng eiia k i t cau, cd t h i xac djnh mdt hoae mot sd chl s6 cflng nang eho mdi loai hinh cdng ndng k i l m tra. Ket eau dfloc coi la d i m bao edng nang khi P„ > P [4].
Cdc chl sd cflng nang e i n ddnh gid eiia k i t cau BTCT bao gom do an t o i n ( k h i n i n g chju lUc) v i khd nang lam viee binh t h u d n g . 0 6 an todn bao gdm c i c chl sd mdmen udn, Iflc eat, Iflc d g c lUe x o i n , Iflc gay s i p do hodc mat ong
^ n h k i t cau. K h i nang lam viec binh t h u d n g theo chflc nang k i t eau (chdng t h i m . each nhigt, chdng chiy, chdng on, my quan b l mat);
theo sfl d i m bdo tien nghi cho ngudi sfl dung (do nghieng vdng, nflt, e h i n rung) va theo t i c ddng x i u d i n mdi trudng xung quanh ( k h i nang bong rai bg t o n g , t i c dgng x i u d i n mdi trfldng, dnh hudng d i n cdng trinh I i n c i n ) .
Trong [15] d i n h gia tinh trang k i t c i u theo
chl sd cdng nang Id d d ben. B d b i n dfldc djnh nghia la khd nang k i t eau d i m bao ede chl so cdng n^ng k l tren theo d i i n g mfle do eho phep trong qud trinh sfl dung d u k i l n (theo t h i l t ke).
D o ben dUde coi Id d i m b i o khi eie ehl s6 cdng nang trgn dat duqc d t h d i diem kiem tra v i t h d i diem k i t thuc qud trinh sfl dung dfl kiln.
D o ben dfldc k i l m tra khdng chl bSng phuong phap c^nh Ifldng md edn bSng phflong phdp ban d i n h ifldng.
Xet ve mat t d n g t h i , hg k i t c i u nha silu cao tang c i n d i m b i o khd nang ehiu Iflc ngang. Lu'c ngang tde d u n g , ed the d o gid hoac do dong d i t se Idm eho tda nhd chiu Iflc c3t v i Iflc udn [11]. Vdi Iflc c i t , tda nha khdng dfloc gay b&i lue c i t cling khong duoc nghigng q u i gidi han khdi phuc. Vdi lUe udn, nhd khdng duoc l i t , cdt khdng duOc gay d u d i t i e d u n g cua lUc u6n hay
xac lap thflng s6 cAng Wnh vi ket c i u
• Cfingnghe
• KJthuai - Si>dgng
Xem x a HSCT. xAc l^p cdc chl s6 cdng nang (an todn va si> dung)
xac iapcacth6ng s6 vh chuySn vi va bi6n dang xac lap PP quan tr^c c6ng trinh
Quan trac kit c i u (cflng
ky.
Do chuySn v|
theo phirong dCmg (lOn] va ngang (d|ch chuyen) TCVN 9360 2012 [6], TCVN 94002012 [7], GPS lileo TC qudcl^.
Kiim tra thuang xuyfin Kiim Ira djnh
PhiFO'ng phap 5i>a cho^
cac hir hflng, xuAng cip, gia c i r a ^ KM d u
Kim tra ban dau Trong qua Irlnli nghiem thu bSn giao.
PP tn/c quan, kit hop xem x6t HSCT Lap s6 k&u vk chdt liFong va cdng nang K/C Xi> l j hi hong nhj
ISZ
pp tryu qjan phSt hiSn nghiSng lun. b i ^ dang, thim, gl, hi/ hing b^ m^t . Khio phyc ngay hw hfing nhfl HIT hong nang l6 chi>c kiim tra chi nit
Kiem tra dinh ky 2 nanVmdt Iin, cho loan bfl kit ciu BTCT loa nha PP tn/c quan. Ihi/ khOng pha hoai
Phat hi$n diu hieu hit hing cua kit ciu. lap bign phap
Kiim tra d ^ xuat Khi kit ciu c6 diu hieu hi/ hdrg dot ngOl Tn/c quan, d/gia linh trang hi/ hong va s6 li$u quan trie Kit luln cin kiim tra chi tiit khdng? Niu khdng thi cd giai phap sira chO^ phuc hii
Niu hu hong cfl nguy co' gay nguy hiim c6 bien phap xir W khin cip
Kiem Ira chi tret Khao sat chl nil toSn bfl (mOt bfl ph|n) K/C bi hie hong PP IttI ngtiiem hifin tn/ftng vi trong phdng Luong hda binq (si lifu hinh anh) tinh tr^irtg hir hing biin d^ng. chuyin vi nirt, gay. an mfln, chit li/ong BT cflng nang K/C, s6 li@u quan trSc
Phan tich CO chi, aanh gia mi>c dO luing cip cua K/C O i xuit giai phap va phiri/ng phap sua chQa.
Lam sadi cac vit bin, rSu m6c tren b i mSt kit ciu XCr ly cac vit r i . nui, hu Hong nho trfin b i mat kit ciu Phuongphap va vailieubiodirtT5glhamldiao[4,14]
ChQ cOi>g trinh cd thi tu thuc hien sua cbOa nho Iheo khi nang
Sija chOB gia cutmg \(m phai chon dem vf cd nang li/c ph(j hep thi/c hi6n
Nguyen tac sua chOa gia ci/dng dam bao cdng nSng va ae> bin lau cua kit ciu sau khi sua chO'a vat li$u, pp, kj thuat, he ihing si/a c^Oa, gia cu^ng tfieophucng an du'O'c duyet, tham khao [4,14,15,171 Ghi chep, bao cao va luu qiO h i so bao tri theo qyi djnh An loan sir dung vSt liSu, thiit D| vS di$n thi cflng An toan Irong sir dgng dan giao cflng tic Ching d t\hilm mfli Inring do bui, hfla chit, phi Ih
Hinh 3. Qui trinh bdo tri he kit eau ehiu Iflc BTCT nha sieu cao tang
nen trong cdt va nha khdng duoe cong qud gidi han cho phep. Cdng trinh phdi ehju dUdc Iflc dong dat ma khdng mat khd nang chju t i i trong dflng. Mot van dg nfla Id dd rung phii dudi mflc cho phgp de trdnh lim dnh hudng tdi ngudi trong nha va trinh lam vd ede ciu kien khdng ehiu Iflc. Nhu vay, trong qua trinh bio tri edng ndng tong the he ket ciu BTCT nha sigu eao
tang, cac tigu chi cdng nang {dn dmh chdng lit, do eflng khung vieh, do cflng tudng, dao dong) phii thda man ygu ciu cCia tigu chuin thiet ke duoc ap dung.
Khi sfl suy giam edng ndng eUa ket ciu BTCT den mfle do g i * han, dan den sfl nguy hiem eCta ket eau nha thi phii ip dung eac phflong phdp kiem tra vi ddnh gia tinh trang cdng nang va
mflc dd nguy hi^m ci^a ket ciu. Co sd eua cic phflong phdp ddnh gii la TCVN 9381-2012 l-ludng dan dinh gid mflc dd nguy hiem cua kgt ciu nha" [5] vd cac tieu chuan khdc cd lign quan.
b) Cdc dang hu hdng thudng gap 6 kit cau BTCT
Hfl hdng 6 ket eau BTCT bao gdm hu hdng doi vdi be tdng va hu hdng edt thep. Nguygn nhin gay hu hdng bg tdng gdm: i) ed hpc: va dap, qui til, ehuyen vi, chay nd va chin ddng;
li) hda hgc: kigm hda cdt lieu be tdng, tic ddng eUa xam thflc mdi trudng, tie ddng cfla vi sinh;
lii) vit 1^ hoc: bien ddi the tieh, ket tinh mudi, xung nhiet, co ngdt, mdi, xdi mdn. Nguyen nhan gdy hU hong edt thep la do hien tflong an mon cdt thgp bdi sU xam thue eOa mdi trudng qua ldp be tong bio vg.
Dau hlgu hu hdng cua be tdng l i hign tuong nflt, thfldng l i dau higu dau tien cua nhflng hu hdng nang hon trong kgt ciu.Thdng thudng nhflng vet nflt gdy ra lien quan dgn tinh tfl bign va co ngdt cCia bg tdng vdi be rdng nhd, cd hudng vudng gdc vdi chieu dii kgt ciu, v i xuit hien trong eae khoang thdi gian 6iu dan.
Nflt cung c6 the do nguyen nhin tdi trong, 6 thd cang eua dam, san, d gan gdi tUa ei!ia dam da duoe du dodn trUde.Tuy nhign, nhflng vet ed be rdng Idn, nflt do liin, chuydn vj, hoae nflt tai nhflng vj tri khdng mong ddi eh? ra sfl qua tdi hoac thiet kg khdng diing ci!ia ket ciu. Vgt niilt cd th^ do an mdn edt thep. An mdn edt thep se khien cdt thep tang the tich tfl 4 dgn 5 lan so vdi ban diu, tao flng suit keo trong be tdng, neu vUOt qua eUdng do chiu keo cOa bg tdng, bg tdng sg nflt. Cot thgp cang gi, vet nflt se md rgng ra be mat be tdng. Vet nflt tao dieu kign de do am vd khdng khi tiep tuc xSm nhap vao bg tdng, kgt qui l i edt thgp tiep tue bj an mdn vdi mfle do Idn hdn [15].
An mon cot thep xiy ra d hai hinh thflc co ban: an mdn do cacbonat hda va an mdn do ion clorua. Thiet ke ket cau va chit luong be tdng anh hudng trflc tiep den nguy eo an mdn. Be tdng rong vdi ti le N/X cao se cho phep khdng khi va dd am nhanh chdng xim nhap vao c6t thep. Be tdng rdng vdi ham luqng cacbonic cao cd khi nang dan dign tdt, thiic day ca che an mdn cdt thep. Be tdng cd chfla ion clorua cung de dan den dn mdn khi ion clorua ket hop vdi oxy vd mdi trUdng am d be mat edt thep. He qui cOa an mdn Id edt thgp mat dan khi nang ehiu Iflc va bg tong bi nflt, ldp bio ve bi phi hiJy.Tinh trang an mdn cdt thep dUdc ddnh gii qua do pH, ham luong ion clorua, thiet dign cot thep, thiet dien kgt ciu va mflc dd dim bdo khi nang chiu lUeeUa ket ciu.
4. Quy trinh bao tri ket cau BTCT nhi sieu caotJngdVJgtNam
4.1. Chinh sdch bdo tri
Ddi vdi nhi sieu eao ting, edng tic bdo tri kgt eau BTCT phdi duqc xem xgt tren nhieu khfa canh: ehinh sdch bao tdn bat dgng sin, phuong
10!
an khai thae sfl dung toa nha, hieu qud kinh te va ky t h u i t b i o tri. Chinh sach b i o tri ket cau BTCT dugc thiet lap t f l giai doan thiet ke dU an dau t u eCing vdi chien lucre xay dung va khai thac, bdo tdn tdi san. Qua chinh sach b i o tri, kg hoach b i o tri tdng the, cdc van de ky thuat, ngudn Iflc, kinh phi, dang hgp ddng va nha thau b i o tri duqc d[nh hinh ro rang hon.
Tigu ehf cda mgt chinh sach b i o tri hieu q u i la chi phf b i o tri tdi Uu va d i m bdo sU hoat ddng an todn, lien tue ciia tda nhd. Can cfl vao nguon lUc tai ehinh, can xac djnh d f l toan chi phi b i o tri va kha nang tuong thich cua chiing vdi cae ket qud duoc d u dodn va quyen Uu tien can thiep sfla chfla da ehl dinh, phu hgp vdi ehien luge xaydUng, khai thdeva gidi han cCia kg hoach tai ehinh.
Trgn quan diem q u i n ly tdi s i n hflu dung, chii sd hflu nen lUa chgn sU Uu tign bdo tri ddi vdi tflng loai ket eau BTCT cUa tda nhd dua trgn vai trd, cdng nang va dieu kign Idm viee eiia ehUng. Vdi su hd tro cCia cdc cdng cu chuan dodn, trgn ca sd chinh sdch bdo tri va eae quy dmh ludt phdp cd tign quan, xde dinh nhdm ddi tuong ( k i t cau), phuong thflc, mue tieu va t h f l t f l Uu tign bdo tri, sfla chfla ddi vdi ket eau BTCT tda nhd.
4.2, Ki hogeh bdo tri tdng thi Ke hoach b i o tri t d n g the Id cong cu qudn ly chCi dao cho hoat dong bdo tri, sSp xgp t h d i gian cho ede can thigp sfla chfla, nhdn biet vd ehi ^ n h ngudn luc can thiet eho qua trinh thflc hign nhflng chign lupc trudc dd. Muc tigu la tdi uu hda todn b d khd nang vdn cd ciia tda nha vd tflng bd phdn cau thanh dde lap ciia nd b i n g cacli quygt dinh mfle bao tri dugc thuc hien va tan suat can thigp sfla chfla. Ndi dung eCia ke hoach b i o tri tdng the can neu bdt duoc' i) su phan ehia tda nha thanh cac ti^u he thdng, bd phan eau thanh vd hang muc vdi mdt trat tuphCi hgp c i u true phan ehia xdy dflng; ii) phan tieh rui ro eiia tda nhi_ya cac tieu he t h d n g , bd phan eau t h i n h ciia nd nam trong cau triie phan ehia xay dflng; in) so sdnh phdn tieh riii ro vdi chien luoc x i y dung da thiet lap trudc dd; iv) xac djnh eae edng vigc b i o tri sg tign hdnh eho m6i tieu hg thdng va bg phdn eau thdnh; xde ^ n h ngudn tdi nguyen s i n cd eho bdo tri (hinh 2).
4.3. Quy trinh bdo tri kit cdu BTCT nhd sieu eao tSng 6 Wit Nam
Qui trinh b i o tri co b i n ket c i u BTCT ciia tda nhd dUde ldp tren co sd eiia ke hoach b i o tri t d n g t h i . Qui trinh bdo tri cy the eho tflng bd p h i n kgt c i u dUde hodn thign trong q u i trinh thi edng dua trgn edc can cfl: quy chuan, tieu chuan ky t h u i t ap dung cho cdng trinh;
dieu kien t f l nhign nai xay dUng; c i c quy dinh eiia eO quan nha nUdc cd t h i m quygn va duoc ban giao eho ehii dau t f l t r u d c khi v i n hanh khai thde. Ndi dung quy trinh bdo tri kgt cau quy
^ n h ve t h d n g so ky t h u i t - cdng nghe; quan tr3c, kiem tra; b i o dfldng, siia chfla, gia eUdng
ket cau va cac bien phap d i m bdo an todn lao ddng, ve sinh mdi trUdng trong q u i trinh thflc hign (hinh 3).
Ket iuanva kien nghi:
- Ket cau BTCT cdt thep nha sieu eao t i n g ed ygu cau vg an toan vd cdng nang dae biet ddi hdi phai xay dung chinh sach, ke hoach v i qui trinh bao tri khoa hgc, phij hop de ap dung trong dieu kien Viet Nam
- Oe xuat trinh tU lap kg hoach bdo tri t d n g the eho he ket eau BTCT nha sieu cao t i n g dViet Nam tren co sd ehinh sdeh qudn ly khai thde tda nhd, ngudn tai nguygn bd trf cho bdo tri, ket q u i phan tich hg thdng vd bd phan cau thanh tda nha. Oac bigt lUu ^ den vigc phan chia hg ket cau toa nha t h i n h c i c t i l u he t h d n g , bd p h i n eau thanh vdi mgt trat tU phii hgp eau triie phan ehia xay dflng de phue vu xac lap qui trinh b i o tri.
- Quy trinh b i o tri ket cau BTCT nha sieu eao tang d Viet Nam duoe de xuat d d a n g so do khdi, lam rd trinh t u va mdi quan he cae cdng tde, ehi d i n noi dung quan t r i e vd kiem tra ket c i u ; x i e lap nguyen tae, hg thdng bdo dudng, sfla chfla h u hdng xudng cap v i gia eUdng ket eau.
- Q u i trinh thiet lap vd thflc hien qui trinh b i o tri ket eau BTCT nha sieu cao t i n g d Viet Nam phdi can cfl cac qui chuan, tieu ehuan da duoc sfl dung trong thiet ke, thi cdng, nghigm thu, van hanh cdng trinh va c i c tieu e h u i n Viet Nam va nUdc n g o i i k h i c phii hgp.
- Kien n g h j d a u t U n g h i g n cflu k h g a h o e v d i q u i m d p h i i h o p d e s d m b a n h d n h t i g u c h u a n ( h u d n g d a n ) b i o t r i k e t c a u BTCT n h a sieu eao t a n g , d a p flng n h u eau t h f l c t e t r o n g q u d n ly x i y d u n g h i g n nay.
TAltiEUTHAMKHAO:
1, Quoc hoi Viet Nam (2003), Lual nay diflig so 16/2003/
QH11,NhaxuatlianXaydiAig,ifaN6i.
2.Thu tUiSng Oiinh phii (2010), Nghi dinh 114/2010/Nfi-CP ve Sao tri cong trinh XD.
3. Bo Xa/ dimg (2012), Thong \\l so 02/2012m-BXD ban hanh Huang dan mot so noi dung ve bao tri cong trinh xiiy di/ng, cong trinh cong nghiep vat lieu xay dung va cong trinh ha tSng ky thuat do thi.
4 TCVN 9343 2012, Ke't cau be tong va be tong cot thip - Hudng dan cong tac bao tri.
5. TCVN 93S1 '2012, Hu^g dan danfi gia mile do nguy litem cila kit d u nha.
6.TCVN 9360.1012, Qui trinh xac dinh do lun cong trinh d5n dung va cong nghiep bSng phi/ong phap do cao hinh hoc
7. TCVN 9400 2012, Nhava cong trinh dang thap-X^c dinh do nghieng bang phuong phap trie dja.
8 Ho Ngoc Khoa (2013), "Bio (ri ke't cau bao che nha sieu tao tang d Viet Nam'Tap chi KHCN Xay dUng, so 18/12, fiai hoc XSy dung. Ha Noi.
9. Tran Hong Hai, Ho Kgoc Khoa (2012),"Cong nghe th) cong nha sieu cao tang betong toin khoi" Tap chi KHCN Xay dung, so 11,OaihocXaydUng,HaNdi.
10. Shahrooz, Bahram M. (2011), Design of conaete stmctures using high-strength steel reinforcement.
Transporiation Research Board, Vol. 679
ll.Taranath, BungaleS. (2009), Reinforced concretedKign oftall buildings, CRC Press
12. International Code Council (2012), Intemational Property Maintenance Code.
13. BS EN 15331:2011, Qiteria for design managmenl and control of maintenance services for build.
14. EN 1504 (2004), Products and Syetem for the protecBon and repair of concrete.
15. JSCE Standard (2007), Specifications for Concretf Structures - Maintenance
16. rocopoij PoccHH (2003) - npaeiina H HopMu rex 3KcnnyaTamiHmuiHuiKoro^Hfla.
17. MKHitaepcTBo wwiHuiHo-KOMMyHanbHaro xosniiaBa Pecny6niiKH Eenapycb (2006) - MeTOflH^iecKiie penoMeHjiaiiiw noTexHMMecKoii aKcnnyaraiiiiM )Kiviiiu|Horo iJiOHjia.
18. CP 13-102-2003 ilpaeM/ia o6oiejtosaHHfi Necyu|HX apoHie/ibHbix KOHcrpyKUHii iRiHM H coopy^KeHHii
