2010.07.12 Tccs 02.2010-Tcdbvn Tieu Chuan Tc Cau Duong Bo Aashto

TCCS T I U C H U N C S

B GIAO THNG VN TI TNG CC NG B VIT NAM

TCCS 02:2010/TCBVN

Xut bn ln 1

TIU CHUN THI CNG CU NG B - AASHTO LRFD

AASHTO LRFD Bridge Construction Specifications

H NI - 2010

TCCS 02:2010/TCBVN

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Li ni u

Tiu chun ny c bin dch t Tiu chun thi cng cu ng b AASHTO LRFD phin bn ban hnh nm 2004 v c b sung cc sa i ca phin bn ban hnh nm 2007. Cc ni dung ca Tiu chun gc c bn c gi nguyn nh c v ch sa i mt s ch sai st trong nguyn bn ting Anh. B Giao thng Vn ti c cng vn s 8579/BGTVT-KHCN ngy 4/12/2009 ngh Cc ng b Vit Nam (nay l Tng cc ng b Vit Nam) t chc cng b tiu chun ny di dng tiu chun c s (TCCS). Ngy 20/8/2010, B Giao thng Vn ti c vn bn s 5756/BGTVT-KHCN ngh Tng cc ng b Vit Nam cng b v p dng th nghim trong vng 2 nm. TCCS 02:2010/TCBVN do Hi cu ng Vit Nam bin son, V Khoa hc Cng ngh ca B Giao thng Vn ti xt duyt, Tng cc ng b Vit Nam ban hnh.

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NI DUNG TIU CHUN Tiu chun ny bao gm Phn m u v 32 phn c bin dch t Tiu chun thi cng cu AASHTO LRFD ln xut bn th 2 nm 2004 theo h n v o lng quc t SI, c th nh sau :

1. o v lp kt cu 2. Tho d kt cu hin c 3. Cng trnh tm 4. Mng cc ng 5. Cc khoan v ging khoan 6. Neo t 7. Cc kt cu chn t 8. Kt cu b tng 9. Ct thp 10. To ng sut trc 11. Kt cu thp 12. Mt cu mng dm thp 13. Sn 14. xy 15. Cng trnh xy bng khi b tng v gch 16. Kt cu g 17. X l bo qun g 18. Gi cu 19. Tm bt khe ni mt cu 20. Lan can 21. Lp phng nc 22. Bo v mi dc 23. Kim loi linh tinh 24. Va phun bng kh nn 25. Tm lt hm bng b tng v thp 26. Cng kim loi 27. Cng b tng 28. B mt chu mi mn 29. Neo chn 30. ng nha do nhit 31. Kt cu nhm 32. B truyn va p

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PHN M U

1. M u

tin s dng, phn Ch gii (Commentary) vi k t C trc ca mi iu c thc hin ngay sau mi iu ch khng vit thnh ct trang bn phi ca phn tiu chun nh trong bn gc, hoc lp thnh sch ring nh trong Gii thch tiu chun thit k cu 22 TCN 272.05. Phn ny c in nghing phn bit vi phn Tiu chun. Trong ti liu gc khng c mc nh ngha (thut ng) nh Tiu chun thit k nn chng ti khng lp thm. Mt s thut ng mi c ch gii khi xut hin ln u trong Tiu chun Tiu chun thi cng cu v c bn c trnh by theo mu ca TCVN 1-2: 2003. Phn 2 : Quy nh v trnh by v th hin ni dung Tiu chun Vit Nam v Thng t s 21 & 22/2007/TT-KHCN ngy 28/9/2007 ca B Khoa hc cng ngh hng dn v xy dng v p dng tiu chun. C bit c theo cch ca AASHTO tin i chiu. Trong Tiu chun ny cc t Ch u t (Owner), Nh thu (Contractor) v K s (Engineer) c vit hoa l ch 3 vai chnh trong cc hp ng thi cng xy dng theo c ch th trng. Trong K s c hiu l k s t vn gim st trng ca d n (hoc k s t vn gim st c ng ta u nhim). Cn k s ng b chuyn nghip l k s ca Nh thu. Khi cha c h thng ng b k s c hiu l k s chuyn nghip ca nh thu. Tn cc iu nh cp 5 (1.1.1.1.1) dng ch thng vit nghing theo nh bn gc. Thut ng nc ngoi do cha c trao i thng nht nn c ch tm dng nguyn gc ting Anh, c ch phin m Vit theo t in hoc theo m Vit ho ph cp. Hu ht cc Tiu chun trch dn trong Tiu chun ny l thuc h thng Tiu chun AASHTO v ASTM, nhng cng cn mt s Tiu chun ca cc lnh vc khc ca Hoa K. Cc ti liu vin dn bng ting Anh cui mi phn vn nguyn ting Anh tin s dng. Ch thch v nguyn bn ting Anh ca Tiu chun thi cng cu AASHTO LRFD:

o Tiu chun thi cng cu AASHTO LRFD l ti liu song hnh cng Tiu chun thit k cu AASHTO LFRD m Cc ng b lin bang Hoa K cng cc bang t ra mc tiu l sau nm 2007 cc Tiu chun LRFD phi c dng thit k cc cu mi.

o Cc Tiu chun tm thi (Interim Specifications) thng c pht hnh vo gia nm, c gi tr nh cc Tiu chun, gm cc sa i d kin c t nht 2/3 thnh vin ca Tiu ban cu v kt cu chp thun v s a vo ln xut bn mi.

o Tiu chun thi cng cu AASHTO LRFD xut bn ln th hai nm 2004 cng cc Tiu chun tm thi cc nm 2006 v 2007 l ti liu cp nht ti 2007 ca AASHTO v thi cng cu.

o Nguyn bn ting Anh dng cho c 2 h n v o lng Hoa k (US . Units) v n v o lng quc t (SI. Units). Trong bn dch ny ch dng h n v quc t tin s dng. Trong 32 phn ca Tiu chun thi cng cu AASHTO LRFD 2004 so vi Phn II ca Tiu chun thi cng cu AASHTO LRFD 1998 v ca Tiu chun thit k cu AASHTO LRFD 1998 c th c nhng phn c sa i ng k cp nht cc cng ngh mi, nh cc phn 3, 8, 10, 11, 18, 19, 27. C 3 phn mi thm so vi ln xut bn u tin nm 1998 l cc phn 30, 31 v 32.

o Bng vit tt cc n v o lng dng chung cho cc tiu chun LRFD theo n v quc t c lit k di y:

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n v Vit tt n v Vit tt

mt khi m3 megapascal MPa ngy ngy mt

mt vung mt khi micron

mt, m m2

m3

mm

celsius

oC mililt

milimt

ml

mm

gi giy

gi, h giy, s

Newton N

hc Hz Newton mt Nm Joule, Jun J Newton/mt

ngy N/m ngy

Kilmt/gi Km/h Pascal Pa kilonewton kN Pascal second

pht Pa.S

pht, min kilopascal kPa radian rad lt L Radian/giy rad/s

2. Phm vi p dng

Tiu chun ny c khuyn co p dng i vi cng tc thi cng v nghim thu cu v cng cho cc cu mi c kt cu thng thng v p dng cc cng ngh thng thng trn ng t, ng thnh ph. Phm vi p dng ca Tiu chun ny bao gm:

o Dng ch o thi cng cc cng trnh cu ng b Vit Nam nhm m bo cht lng, an ton v thn thin vi mi trng.

o L Tiu chun hi ho vi cc Tiu chun thit k v thi cng thng dng trn th gii ang c cc d n ODA v giao thng a vo cc Hp ng gia Ch u t v Nh thu, gia Ch u t v T vn gim st Vit Nam qua cc Ch dn k thut trong h s hp ng.

o Lm c s cho cc Nh thu tham kho lp cc Quy trnh cng ngh c th cho tng hng mc trong cc d n c th

Ngoi cc quy nh trong Tiu chun ny, trong thi cng v nghim thu cu v cng, cn cn phi tun theo cc Tiu chun hin hnh khc ca B GTVT v Nh nc c lin quan trong phn cc Tiu chun vin dn. Tiu chun ny khng cp ti vic kim tra, xem xt i chiu vi cc thit k cu. Cng tc ny cn phi c thc hin theo nhng quy nh chung ca Nh nc v nghim thu cc cng trnh xy dng c bn.

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3. Ti liu vin dn

(xp theo th t ban hnh t cc nm gn y)

o TCXDVN 364 : 2006 Tiu chun k thut o v x l s liu GPS trong Trc a cng trnh" o TCVN 7570: 2006 Ct liu cho b tng v va. Yu cu k thut o 22TCN 272:2005 Tiu chun thit k cu o TCXDVN 309:2004 Cng tc trc a trong cng trnh xy dng o TCXDVN 325:2004 Ph gia ho hc cho b tng o TCXDVN 327:2004 Kt cu b tng v b tng ct thp - Yu cu bo v chng n mn

trong mi trng bin. o TCXDVN 305: 2004 B tng khi ln - Quy phm thi cng v nghim thu o 22TCN288-02 Tiu chun dm cu thp v kt cu thp - Yu cu k thut ch to v

nghim thu trong cng xng o TCXD VN 262:2001 B tng nng -Phng php xc nh hm lng Clorua trong ct liu v

b tng o TCVN 2682:1999 Xi mng pooc lng - Yu cu k thut o TCXDVN 238:1999 Ct liu b tng - Phng php ho hc xc nh kh nng phn ng

kim silc o TCXDVN 234:1999 Ni ct thp c g o TCVN 6260:1997 Xi mng pooc lng hn hp - Yu cu k thut o TCVN 6067:1995 Xi mng pooc lng bn sunpht - Yu cu k thut o TCVN 6069:1995 Xi mng pooc lng t to nhit - Yu cu k thut o TCVN 4787:1989 Xi-mng Phng php ly mu v chun b mu th o TCVN 338:1988 Ct xy dng Phng php xc nh thnh phn khong vt o TCVN 1772:1987 , si trong xy dng Phng php th o TCVN4506:1987 Nc cho btng v va Yu cu k thut o TCVN 1770:1986 Ct xy dng Yu cu k thut o TCVN 1771:1986 dm, si v si dm dng trong xy dng Yu cu k thut o TCVN 1651-1985 Thp ct b tng cn nng o AASHTO M203M (ASTM A416M) Tao thp 7 si d ng lc khng sn ph, c kh ng

sut cho b tng d ng lc hoc o AASHTO M275M (ASTM A722) Thp thanh cng cao khng sn ph dng cho b

tng d ng lc.

PHN 1: O V LP KT CU 1 - 1 -

PHN 1: O V LP KT CU MC LC

1.1 TNG QUT 1.2 BN V THI CNG. 1.3 VT LIU... 1.4 THI CNG. 1.4.1 Chiu su mng.. 1.4.2 Chun b mng v khng ch nc.. 1.4.2.1 Tng qut 1.4.2.2 o trong dng nc 1.4.2.3 Mng trn .. 1.4.2.4 Cc mng khc.. 1.4.2.5 Chp thun nn mng.. 1.4.3 Lp t 1.5 O C V THANH TON 1.5.1 o c. 1.5.2 Thanh ton. Ti liu vin dn..

1-2 1-2 1-3 1-3 1-3 1-3 1-3 1-3 1-4 1-4 1-4 1-4 1-5 1-5 1-5 1-7


PHN 1 O V LP KT CU

1.1 TNG QUT

Cng tc o bao gm vic loi b tt c cc loi vt liu, d bn cht th no, cn thit cho vic thi cng mng cu, tng chn v cc kt cu ch yu khc theo h s hp ng hoc theo ch dn ca K s ( trong Tiu chun ny c hiu l K s t vn gim st trng hoc i din ca ng ta).

Nu khng c cc quy nh khc trong hp ng, cng tc o phi k c vic cung cp tt c cc thit b cn thit, vic thi cng v sau thu dn tt c cc vy, ct chng v cc h thng khng ch nc cn thit cho vic thi cng cng trnh.

N cng phi gm c vic lp t cn thit, nu khng c quy nh no khc trong h s hp ng, k c vic lu gi cn thit cc loi vt liu o ln c dng lp li v em cc vt liu khng cn thit cho vic lp li, cho nn ng p hoc theo quy nh i vi vt liu tha khng ph hp trong Tiu phn 203.02. Tiu chun hng dn thi cng ng t ca AASHTO.

Nu hp ng khng c mt mc thanh ton ring cho cng vic ny th cng tc o phi gm mi vic dn quang, o gc cy v d b cc kt cu hin c trong khu vc phi o.

Nu c, vic phn loi cng tc o phi c ch r trn h s hp ng v nu ln trong bn kin ngh.

Vic thu dn v em i cc vt liu t nhin hoc nhn to chn di t c a vo trong cp loi cng tc o ti ni c cc vt chn vi , tr khi vic thu dn v i nh vy c k vo cc hng mc khc ca cng trnh. Tuy nhin, trong trng hp vt chn vi l nhn to th vic thu dn v i ca cc vt ny s c chi tr nh cng vic lm thm v khi lng ny s khng bao gm trong khi lng o c ca h o nu:

vic loi b vt cn dng n cc phng php hoc thit b khng c s dng cho cc cng vic o khc trong n,

s tn ti ca vt khng c ch r trn cc bn v trong hp ng, s tn ti ca vt c th khng c xc nh trong kho st hin

trng, k c vic gp phi cc cng trnh tin ch cng cng trong khu vc,

nh thu yu cu nh vy bng vn bn trc khi thu dn vt . Ch gii: Tiu phn 203.02 trong Tiu chun hng dn thi cng ng t ca AASHTO.

1.2 BN V THI CNG

Khi c quy nh trong bn v hp ng, Nh thu phi cung cp cc bn v thi cng, km theo nhng tnh ton thch hp v phng php o, thi cng nn p v cc thao tc lp t. Bn v ny phi cho thy cc chi tit ging, chng, x l mi dc hoc h thng bo v kin ngh s dng khc v phi km theo cc tnh ton thit k


v cc s liu xc minh chi tit cho php xem xt v k thut bn thit k ngh. Cc bn v thi cng bo v chng ln st phi np trc khi s dng c thi gian xem xt, sa li nu cn thit v chp thun khng gy chm tr cho cng vic. Cc bn v thi cng phi c K s chp thun trc khi thc hin cng vic c lin quan v vic chp thun ny khng gim nh cho Nh thu khi bt k trch nhim no trong hp ng hon thnh tt p cng vic.

1.3 VT LIU

Vt liu dng lp khng c c cc cc b ng bng, g hoc cht c th b mc rung hoc nguy hi khc v phi c cp phi sao cho t c cht yu cu mt cch thch hp bng cch dng cc phng php m cht do Nh thu la chn. Vt liu thm nc lm rnh tiu nc ngm phi ph hp vi iu 704.01 Tiu chun hng dn thi cng ng t AASHTO nh sau: S dng ct cng bn v sch, si cui, nghin hoc x nghin lp ho, xy rnh thot nc ngm hoc cc mc ch thot nc ngm khc. Bo m vt liu thm nc khng cha cht hu c, cc st hoc cc cht c hi khc. Ch gii: Tiu phn 704.01 trong Tiu chun hng dn thi cng ng t ca AASHTO.

1.4 THI CNG

1.4.1 Chiu su b mng Cao y b mng, nh cho trn h s hp ng, ch c xem l gn ng v K s c th yu cu bng vn bn v cc s thay i v kch thc hoc cao b mng cn thit m bo mt b mng tho ng.

1.4.2 Chun b mng v khng ch nc 1.4.2.1 Tng qut Tt c cc kt cu phn di, khi c th, phi thi cng trong cc h o h v khi cn thit h o phi ging chng hoc bo v bng cc vy thi cng theo cc yu cu trong iu 3.3 vy v khung chng. Khi mng c th t kh khng s dng vy, c th b cc khung chng vi s chp thun ca K s, ton b h o c y b tng ti cao yu cu ca mt trn mng. Lng b tng yu cu tng thm phi c cung cp v vi chi ph ca Nh thu. Cc h thng khng ch nc tm thi phi ph hp vi cc yu cu trong iu 3.4 H thng khng ch tm thi mc nc. 1.4.2.2 o trong dng nc Khi o trong mt dng knh hoc sng sui, tr khi c php lm khc, khng c o pha ngoi cc ging chm, ci, vy, cc thp hoc cc vn, lng sng thin nhin cnh kt cu khng c lm xo trn nu khng c K s cho


php. Nu o hoc no vt ti a im kt cu trc khi h ging chm, ci hoc lm vy kiu dm hoc ti ch, sau khi nn mng lm xong, Nh thu phi lp tt c h o ti mt t trc khi xy mng hoc y sng bng vt liu c K s ng v khng c thm mt khon tin no. Vt liu o t mng hoc cc h o khc c cht tm trong khu vc dng chy ca sng phi thu dn khu vc dng chy khng cn b cn tr. 1.4.2.3 Mng trn Khi mng t trn gc, gc phi khng c t ri rc, sch s v o ti mt mt phng, hoc bng phng, nh bc hoc g gh, theo ch dn ca K s. Cc khe ni phi lm sch v nhi y b tng, va hoc va phun trc khi lm b mng. Khi cn n mn b mng t n cao thit k, tt c cc mnh vn, ri rc b ph thp hn cao chu ti phi c loi b hoc thay bng b tng hoc phun va bng tin ca Nh thu. 1.4.2.4 Cc loi mng khc Khi mng nm trn nn o khng phi l , phi c bit lu khng c xo trn y h o v vic loi b cui cng vt liu nn ti cao d kin ch c thc hin ngay trc khi b mng. Khi t di y b mng khng c cc b xo trn, t phi vt i v thay bng b tng hoc vt liu c chp thun khc bng tin ca Nh thu. Di cc b mng c cc , th tch o qu hoc b xo trn phi c thay v lu ln theo ch o ca K s. 1.4.2.5 Chp thun nn mng Sau khi o xong, Nh thu phi thng bo cho K s v khng c b tng hoc vt liu mng khc trc khi K s chp thun chiu su h o v c tnh ca nn t.

1.4.3 Lp t t lp phi ph hp vi cc quy nh ca iu 1.3 Vt liu. Nu khng c t c cht lng ph hp ly t h o trong gii hn d n, Nh thu phi ly vt liu t ni khc n theo ch dn ca K s. Tr khi c quy nh khc trong h s hp ng, tt c cc khong khng lp khng b m, tr, hoc cng trnh vnh cu khc chim phi c lp li bng t cho ti b mt ca t xung quanh, vi d tr cho ln. Tr khi c cc quy nh khc, tt c t lp phi lu ln k cng ti cht ca t xung quanh, mt trn ca t phi san gn gng. t lp xung quanh tr phi sao cho c gn cng mt cao cng mt thi im hai bn tr. c kch thc ln hn 75 mm khng c ln trn mt b tng. Thi cng nn t phi ph hp vi cc yu cu ca Tiu phn 203.02 Tiu chun hng dn thi cng ng t ca AASHTO. t lp ti cc tng chn, m, tng cnh, cc tr khung trong nn ng p phi ri thnh tng lp nm ngang khng qu 150 mm, c m ln tt v phi lp ln trn tt c cc pha ca kt cu hoc cng trnh mt cch ng u. t lp trong hoc bn di nn ng p, bn trong lng ng trong cc khu vc o, hoc trc cc m v tng chn hoc tng cnh phi lp ti cng mt cht nh yu cu i vi nn ng p.


Nu cha c K s ng , khng c lp trn bt c kt cu b tng no. Vic t lp cng phi theo ng cc yu cu ca iu 8.15.2 Ti trng t. Vic lp t trc m v tng cnh phi lm trc ht phng nga chuyn ng ra pha trc. Khng c php xi nc vo t lp sau m hoc tng cnh. Ti cc l thot nc phi b tr tho ng thot hon ton nc ca t lp, phi t cc rnh tiu nc kiu Php gm t nht 0,06m3 vt liu thm nc bc trong cc tm si lc ngn nga b tc hoc lt cc ht mn ca t p ra ngoi. Vic lp cc cng kim loi v b tng phi thc hin theo cc yu cu ca Phn 26 Cng kim loi v 27 Cng b tng. Ch gii: Tiu phn 203.02 trong Tiu chun hng dn thi cng ng t ca AASHTO.

1.5 O C V THANH TON

1.5.1 o c Khi lng phi thanh ton cho cng tc o kt cu phi o theo mt khi. Khi lng thanh ton phi xc nh t gii hn cho trn h s hp ng, hoc theo lnh ca K s. Khng tr trong khi lng thanh ton ca cng tc o khi Nh thu khng o t nm ngoi gii hn ca kt cu thc t nhng nm trong gii hn thanh ton ca cng tc o. Khi khng c cc quy nh khc trong h s hp ng, cc gii hn thanh ton cho cng tc o kt cu c ly nh sau:

cc gii hn nm ngang s l cc mt phng thng ng cch 450mm pha ngoi ng gii hn mp b mng hoc mp ca kt cu nu khng c b mng,

cc gii hn trn mt l mt t trc khi xy mng hoc nh ca mt ct ngang san i theo yu cu, ly gii hn thp hn,

v cc gii hn pha di phi l y ca b mng hoc y ca kt cu hoc gii hn thp hn ca h o theo ch th ca K s.

Khi mng nm trong nn ng p v cc Tiu chun k thut yu cu nn ng p phi thi cng ti cao quy nh cao hn y b mng hoc y kt cu trc khi thi cng mng, th cao quy nh ny c xem l mt t ban u. Khi cn thit, theo kin ca K s, phi a mng xung di cc cao cho trn h s hp ng th 900mm o su thm c tnh trong khi lng c thanh ton theo hng mc ny. Vic o su thm qu su ny c thanh ton nh cng vic lm thm, tr khi Nh thu tuyn b bng vn bn rng vic thanh ton theo cc gi hp ng l chp nhn c.

1.5.2 Thanh ton Tr khi c quy nh khc, cng tc o c quy nh trong iu 1.5.1 o c s c thanh ton theo mt khi i vi cht t v loi o quy nh trong h s hp ng.


Vic thanh ton i vi cng tc o kt cu phi bao gm y vic b p cho tt c nhn cng, vt liu, thit b v cc hng mc cn thit khc hoc thun tin cho vic hon thnh tt cng vic o ti cao y b mng hoc kt cu. Phi xt vic b p y cho vic khng ch v tho nc khi cc h o v cho vic cung cp lp t hoc thi cng cc vy, thanh chng v tt c cc thit b khc cn cho cc thao tc, tr cc lp b tng bt y c th hin trong h s hp ng, k c vic thu dn chng phi xt n trong gi hp ng i vi cng tc o kt cu, tr khi hp ng quy nh thanh ton ring cho cng tc . Gi hp ng cho cng tc o phi bao gm mi khon thanh ton cho mi vic x l v ct gi t o dng cho vic lp li, k c cng vic lm kh cn thit; v vic thanh thi t o ln cn tha hoc khng ph hp. Tr khi c quy nh khc trong hp ng, mi vic dn quang, o gc cy hoc thu dn kt cu cn thit, nu khng thanh ton trong cc hng mc khc ca h s hp ng, s c xt gp vo gi thanh ton cho cng vic o kt cu. Tr khi hp ng quy nh thanh ton ring, gi hp ng cho cng tc o phi b p y cho vic v m ln t lp. Vic cung cp vt liu lp t cc ngun ngoi h o s c thanh ton theo n gi hp ng i vi vt liu s dng, hoc theo cng vic lm thm nu khng lp c n gi.


Ti liu vin dn

AASHTO.1998. AASHTO Guide Specifications for Highway Construction, GSH-8, American Association of State Highway and Transportation Officials, Washington, DC.

PHN 2: THO D KT CU HIN C 2 - 1 -

PHN 2: THO D KT CU HIN C MC LC

2.1 M T 2.2 BN V THI CNG. 2.3 THI CNG. 2.3.1 Tng qut 2.3.2 Tn dng. 2.3.3 Tho d mt phn kt cu.. 2.3.4 Thu dn cng trng.. 2.4 O C V THANH TON

2-2 2-2 2-2 2-2 2-3 2-3 2-3 2-4


PHN 2 THO D KT CU HIN C

2.1 M T

Cng vic ny bao gm vic tho d hon ton hoc mt phn, v thu dn cng trng, hoc tn dng tt c cc cu, tng chn v cc kt cu ch yu khc phi tho d c ch nh trong h s thu. Tr khi c quy nh khc, cng vic ny cng bao gm mi vic o v lp cc ho, cc l hoc h o do vic tho d m c. N cn bao gm mi chi ph cho h thng gim st mi trng v sc kho hoc cho cc k hoch khc c th c yu cu.

2.2 BN V THI CNG

Bn v thi cng cho bit cc phng php v trnh t tho d: khi cc kt cu hoc cc phn ca kt cu c quy nh phi tho d v

tn dng, khi cng tc tho d c thc hin trn hoc lin k ng xe chy hoc

ng st, hoc khi c quy nh trong h s hp ng.

t nht 10 ngy trc ngy d kin bt u cng vic tho d, cc bn v thi cng phi np cho K s c chp thun. Cng vic tho d khng c bt u trc khi bn v c chp thun. Vic chp thun ny khng gim nh trch nhim ca Nh thu c quy dnh trong h s hp ng cho vic hon thnh tt cng vic. Khi cn tn dng, cc bn v phi ch r rng cc du hiu ra t tn cc phn on ring r ca kt cu.

2.3 THI CNG

2.3.1 Tng qut Tr cc cng trnh tin ch cng cng v cc hng mc khc m K s c th ch th cho Nh thu li mt cch nguyn vn, Nh thu phi san bng, tho d v thanh thi mi kt cu hoc b phn kt cu c ch nh phi tho d. Tt c b tng v cc mng khc phi tho d ti su t nht 600mm di cao mt t hoc 900mm di cao lp mt nn ng, ly cao no thp hn. Tr khi c cc quy nh khc trong h s hp ng, Nh thu c th hoc nh cc cc hoc ct chng ti im khng t hn 600mm di mt t. Cc l hng li do vic tho d kt cu phi lp n cao ca t xung quanh, nu nm trong khu vc xy dng ng xe chy phi lu ln theo cc yu cu ca h s hp ng p nn ng. Khng c dng thuc n, tr ti cc v tr v iu kin ni trong cc h s hp ng. Tt c vic n mn phi hon thnh trc khi lm cng trnh mi.


2.3.2 Tn dng Cc vt liu c ch nh phi tn dng trong h s hp ng dng li trong d n hoc cho tng lai, phi thuc v ti sn ca Ch u t v phi c tho d cn thn thnh tng on c th vn chuyn c v phi ct gi gn cng trng ti v tr do K s ch nh. Nh thu phi khi phc v thay th vt liu h hng hoc b ph hu m khng c n b thm. Cc inh tn v bu lng phi tho ra khi cc kt cu thp c tn dng, phi tho bng cch ty u bng mt ci c, sau t hoc khoan ra khi l, hoc bng phng php khc m khng lm tn thng n cc cu kin s dng li v c s chp thun ca K s. Trc khi tho tt c cc cu kin hoc on kt cu thp phi nh du ch ni vi nhau bng sn theo s hoc bn v c K s chp thun. Tt c cc bu lng v inh phi tho khi cc tm g c K s coi l c th tn dng c nh mt phn ca cc kt cu g tn dng.

2.3.3 Tho d mt phn kt cu Khi kt cu phi m rng hoc sa i v ch phi tho d cc phn ca kt cu hin c, cc phn ny phi tho th no kt cu cn li khng b h hng v trong iu kin thch hp s dng theo d nh. Khng c dng cc phng php c s dng thuc n hoc n ph trong mt nhp hoc tr tr khi phi tho d ton b nhp hoc tr. Bt k h hng no cho cc phn cn li s dng Nh thu phi sa cha bng tin ca mnh. Trc khi bt u cc thao tc d b tng, gm c vic d mt phn ca mt b phn b tng lin khi, phi ca su khong 25mm theo mt ng chnh xc dc theo cc gii hn tho d trn tt c cc mt ca cu kin m c th nhn thy c khi cng vic hon thnh. B tng c c d b cn thn theo cc ng ch nh bng cch khoan, c hoc cc phng php khc c K s chp thun. Cc mt l ra do kt qu ca vic ph b phi tng i chnh xc v bng phng, vi cc gc thng, sc nt cho php ni gn gng v kho lo vi cng trnh mi hoc tho mn s dng theo d nh. Ch no c cc thanh ct thp hin c phi ko di t kt cu hin c sang kt cu mi, phi ph b b tng v li cc thanh thp th ra, sch s v khng h hng. Khi cc thanh thp th ra khng ko sang cng trnh mi phi c ct ngang bng vi b mt b tng c. Trong khi d b ton b b dy ca b tng mt cu trn cc dm ngang hoc dc bng thp s c gi li, Nh thu phi ch khng cho cc cnh trn b vt kha, vt khot hoc vn mo. Mi h hng phi do Nh thu sa cha theo ch dn ca K s v bng kinh ph ca mnh. Cc sa cha c th bao gm vic mi, hn, nn thng bng nhit hoc thay th cu kin tu thuc vo v tr v tnh cht nghim trng ca h hng.

2.3.4 Thu dn cng trng

Bt k vt liu no khng c ch nh tn dng u thuc v Nh thu. Tr quy nh y, Nh thu phi ct gi hoc loi b cc vt liu ny ngoi hnh lang


ng. Nu vt liu c thi b trn mt khu t t, Nh thu phi c giy php do ngi ch t cp v phi np mt bn sao ca mi tho thun cho K s. Cc vt liu ph thi c th vo a im ca Ch u t nu cc a im nh vy c ni n trong cc h s hp ng. Tr khi c cc quy nh khc trong h s hp ng, b tng ph b phi em chn trong nn ng k bn, min l b tng phi p thnh mnh c th x l d dng v chn vo trong nn ng p sau khng t hn 900mm bn di cao hon thin v mt mi dc. B tng ph b khng c chn trong cc khu vc phi ng cc hoc cch cc cy to , ng ng, ct, nh ca, cc cng trnh hoc kt cu vnh cu khc trong vng 3000mm, tr khi K s cho php. B tng d b cng c th bn ngoi hnh lang ng nh quy nh trn. H s hp ng phi ch r mi vt liu c hi bit, bao gm lai lch sn. Vt liu c hi phi c thanh thi ng cch v c ghi chp ph hp.

2.4 O C V THANH TON

Cng vic nh quy nh theo hng mc ny phi c o c cho tng kt cu ring bit, hoc phn kt cu phi d b. Thanh ton c thc hin trn c s gi b thu trn gi i vi vic d b mi kt cu, hoc mt phn ca kt cu nh quy nh trong h s hp ng. Cc gi v thanh ton nu trn phi b p y mi cng vic, nhn cng, dng c, thit b, o, p, vt liu, thanh thi ng n v ph ph cn thit cho vic hon thnh cng vic, k c vt liu tn dng khng s dng li trong d n khi vic tn dng ny c quy nh v khng c thanh ton thm. Vic b p cho vic ph d v tn dng vt liu c s dng li trong d n phi c xem nh gm trong gi hp ng tr cho vic khi phc, xc nh li v tr hoc iu chnh li cc hng mc c lin quan, hoc trong cc hng mc thanh ton khc ca hp ng c th c ch nh trong h s hp ng, khng c khon b p no thm cho vic .

PHN 3: CNG TRNH TM 3 - 1 -

PHN 3: CNG TRNH TM MC LC

3.1 TNG QUT... 3.1.1 M t. 3.1.2 Bn v thi cng 3.1.3 Thit k. 3.1.4 Thi cng 3.1.5 Tho d. 3.2 GIO V VN KHUN... 3.2.1 Tng qut. 3.2.2 Thit k v thi cng gio.. 3.2.2.1 Ti trng 3.2.2.2 Mng.. 3.2.2.3 vng. 3.2.2.4 Tnh khng 3.2.2.5 Thi cng. 3.2.3 Thit k v thi cng vn khun. 3.2.3.1 Tng qut.. 3.2.3.2 Thit k.. 3.2.3.3 Thi cng. 3.2.3.4 Khun ng. 3.2.3.5 Cc vn khun li ti ch.. 3.2.4 Tho d gio v vn khun. 3.2.4.1 Tng qut.. 3.2.4.2 Thi gian tho d. 3.2.4.3 Phm vi tho d... 3.3 VY V KHUNG CHNG.. 3.3.1 Tng qut. 3.3.2 Bo v b tng 3.3.3 Tho d. 3.4 H THNG KHNG CH CH TM THI MC NC.. 3.4.1 Tng qut 3.4.2 Bn v thi cng 3.4.3 Thao tc vn hnh..

3-3 3-3 3-3 3-4 3-4 3-4 3-4 3-4 3-5 3-5 3-5 3-5 3-6 3-6 3-6 3-6 3-7 3-7 3-7 3-8 3-8 3-8 3-8 3-9 3-9 3-9 3-10 3-10 3-10 3-10 3-10 3-10


3.5 CU TM. 3.5.1 Tng qut. 3.5.2 Cu trnh.. 3.5.3 Cu cng v. 3.5.4 Bo tr 3.6 O C V THANH TON.. Ti liu vin dn....

3-11 3-11 3-11 3-11 3-11 3-12 3-13


PHN 3 CNG TRNH TM

3.1 TNG QUT

3.1.1 M t Cng vic ny gm c vic thi cng v thu dn cc cng trnh tm thng do Nh thu thit k v s dng trong thi cng cng trnh v nu chng khng c thc hin ng n, c th nh hng c hi n tnh cht ca cng trnh hp ng hoc gy mt an ton cho cc cng trnh tin ch k bn, bt ng sn hoc cng ng. Cc cng trnh tin ch ny bao gm nhng khng gii hn gio, vn khun, vn khun y, vy, khung chng, h vng vy ngn nc v cu tm. Phi gim thch ng cc ng sut cho php, h s sc khng hoc cc ti trng thit k khi s dng cc vt liu khng phi l mi hoc b h hng. Cc tnh ton phi bao gm vic xc nh cc c trng mt ct c xt n h hng hoc tn tht mt ct n chng mc c th. Tr khi cho php khc i, thit k cng trnh tm phi da vo Tiu chun thit k cu AASHTO LRFD vi cc h s ti trng quy inh trong iu 3.4.1 v 3.4.2, phi tnh ton vi mi t hp ti trng c th. Ch gii: FH WA ban hnh T vn k thut s T5140.24 vo ngy 29/10/1993 lin quan n Cng trnh cu tm. B trng B giao thng Hoa K c quc hi ch o bin son Tiu chun v hng dn dng trong thi cng cu tm. Vic sp gin gio thi cng cu Maryland ng 198 qua cng vin Baltimore/Washington v thc t l khng c mt quy chun hoc tiu chun quc gia no c sn v cng trnh cu tm dn n vic giao nhim v ny. Cc tiu chun hng dn, s tay v chng trnh chng thc l c ch lin quan n phn ny ca tiu chun. Cc bang cng khuyn khch xem xt cc n phm ny a nhng phn ph hp vo tiu chun ca S tay xy dng (xem di) l mt cng c ch dn c ch cho nhn vin kim tra hin trng. Cc n phm di y l cc ti liu tham kho c ch chun b tiu chun thit k, thm tra v gim st cng trnh tm.

Tng hp v gin gio, vn khun v bc gin i li cho kt cu cu ng t, Thng 11-1991 (FHWA-RD-91-062).

Tiu chun hng dn v cng trnh tm cho cu. Thng 11-1993 (FHWA-RD-93-031).

Tiu chun hng dn thit k cng trnh tm cho cu Thng 11-1993 (FHWA-RD-93-032).

Chng trnh chng thc v cng trnh tm cho cu Thng 11-1993 (FHWA-RD-93-033).

S tay xy dng cng trnh tm v cu Thng 11-1993 (FHWA-RD-93-034) 3.1.2 Bn v thi cng Mi khi c quy nh hoc c yu cu ca K s, Nh thu phi cung cp cc bn v thi cng vi cc tnh ton thit k v cc s liu cn c vi y chi tit cho php xem xt li v kt cu bn thit k kin ngh ca mt cng trnh tm thi. Khi c lin quan n b tng, cc s liu phi gm c trnh t v tc b tng. Phi


cung cp bn sao p ng yu cu ca K s v cc c quan khc c thm quyn xem xt. Cc bn v thi cng phi np trc ngy s dng d kin khong thi gian cho php xem xt, sa cha li nu thy cn, v chp thun m khng lm chm tr cho cng vic. Nh thu khng c khi cng bt c cng trnh tm no cn n cc bn v thi cng trc khi cc bn v c K s chp thun. Vic chp thun ny khng lm gim nh trch nhim ca Nh thu i vi kt qu t c do vic s dng cc bn v ny hoc bt k trch nhim no khc theo hp ng.

3.1.3 Thit k Vic thit k cc cng trnh tm phi ph hp vi Tiu chun thit k cu AASHTO LRFD, hoc phi ph hp vi mt Tiu chun hoc Quy trnh k thut thit k khc c xc lp v c chp nhn ph bin cho cng trnh .. Khi s dng cc cu kin ch sn, thit k khng c t ti ln cc cu kin ch sn ny vt qu mc ti trng do nh sn xut cc cu kin ch sn quy nh. Mc ti trng dng cho thit b c bit, nh cc gin phc v lp rp, khng trng hp no mc ti trng c vt qa 80% ti trng ti a chu ng c trong khi th nghim ti trng thit b. Khi c quy nh yu cu hoc quy nh trong h s hp ng, bn thit k phi c chun b v cc bn v phi do k s chuyn nghip k tn. Ch gii: iu 3.1.3 quy nh vic s dng Tiu chun thit k cu AASHTO LRFD hoc tiu chun hng dn thit k cng trnh tm cho cu, tr khi tiu chun c tha nhn khc c K s chp thun Tiu chun hng dn thit k cng trnh tm cho cu tham kho v ti trng thit k. Bc gin gio tip cn bao hm An ton ngh nghip v Qun tr sc kho (OSHA) cn cc gin gio n nh dng lp kt cu thp c thit k nh gin gio.

3.1.4 Thi cng Cng trnh tm phi thi cng theo cc bn v thi cng c chp thun. Nh thu phi kim tra cht lng vt liu v cng ngh s dng c ph hp vi gi nh khi thit k khng.

3.1.5 Tho d Tr khi c quy nh khc, tt c cng trnh tm phi c tho d v vn l ti sn ca Nh thu khi s dng xong. Khu vc phi c khi phc v tnh trng ban u hoc theo trng thi d kin v dn sch rc ri, mnh vn.

3.2 GIO V VN KHUN

3.2.1 Tng qut Bn v thi cng gio phi c k s chuyn nghip lp v ng du khi chiu cao gio vt qa 4300mm hoc khi c giao thng di cu, khng k cng nhn qua li di cu ang thi cng.


gio v vn khun phi cng v cng c mi ti trng t ln n mt cch an ton v to ra ng nt v cp kt cu c hon thin theo quy nh trong h s hp ng. Vn khun cn phi gp phn li cu trc v nhm b mt theo yu cu v khng lm gim tnh ng u v mu sc ca b mt c to khun. Ch gii: gio c xem l mt kt cu tm thi no cc b phn kt cu bng b tng, thp, gch xy hoc cc vt liu khc trong khi thi cng hoc lp rp. Vn khun c xem l cc vt bao quanh hoc cc tm vn cha b tng lng v chu ng cc lc do v m ln b tng. Cc vn khun c cc gio . Cc xe c c dng trong thi cng c hng phn on l mt t hp ca vn khun v gio.

3.2.2 Thit k v thi cng gio 3.2.2.1 Ti trng Ti trng tnh ton i vi gio gm c tng cc tnh ti v hot ti thng ng v mi ti trng nm ngang. Ti thiu, tnh ti phi bao gm trng lng gio v tt c vt liu thi cng m gio phi chu. Trng lng t hp b tng, ct thp, ct thp ng sut trc v vn khun phi gi nh khng nh hn 2560 kg/m3 i vi b tng thng v 2080 kg/m3 i vi b tng nh. Hot ti gm c trng lng thc t ca bt k thit b no phi nh cc ti trng tp trung ti cc im tip xc v mt ti trng ri u khng nh hn 0,001 MPa tc ng trn khu vc c cng thm 1,10 N/mm tc ng ti mp ngoi ca cnh hng mt cu. Ti trng nm ngang dng thit k h ging chng gio l tng s cc ti trng nm ngang do thit b, trnh t thi cng, gm c cc lc thu tnh khng cn bng t b tng lng, dng chy khi c tc dng v tc dng ca gi. Tuy nhin, khng c trng hp no ti trng nm ngang tnh ton theo mt phng no c nh hn 2% tng tnh ti. Vi cc kt cu ko sau, gio cng phi c thit k chu c bt k ti trng tng ln hoc phn b li no do vic to ng sut trc cho kt cu. Cc ti trng do gio tc ng vo kt cu hin c, mi hoc thi cng xong mt phn, khng c vt qu cc ti trng cho php trong iu 8.15 t ti. Ch gii: Trong n v quc t, b tng trng lng thng thng c hiu l b tng t trng thng thng v b tng trng lng nh c hiu l b tng t trng nh. 3.2.2.2 Mng gio phi xy dng trn mt b mng chc chn an ton khng b xi di chn, c bo v khng b ho mm v c th chu c ti trng t trn . Khi K s yu cu, Nh thu phi chng minh bng cc th ti thch hp rng cc gi tr chu nn ca t c gi nh cho vic thit k mng gio khng vt qu kh nng chng ca t. gio no khng th lm trn mt b mng tho ng phi c trn cc, cc phi c b tr, ng v tho d theo cch c chp thun. 3.2.2.3 vng


i vi kt cu b tng c ti ch, vng tnh ton ca cc cu kin chu un ca gio khng c vt 1/240 khu ca chng khng k phn vng c b bng vng ngc to trc. 3.2.2.4 Tnh khng Tr khi c quy nh khc, kch thc ti thiu ca cc khong tnh khng b tr qua cc gio i vi cc ng cn phi m cho giao thng trong khi thi cng phi ln hn b rng ca ng dn n t nht l 1500mm, o gia cc ro chn khi s dng chng. Tnh khng thng ng ti thiu trn quc l v ng cao tc l 4400 mm, trn cc ng khc l 4300 mm. 3.2.2.5 Thi cng gio phi thi cng v b tr dc cho php ln v vng d kin bao gm c trc dc v vng ca kt cu vnh cu c ch r trn h s hp ng hoc theo lnh ca K s. Khi K s ch dn, phi dng cc di vng ngc c chiu cao thay i gia cc dm gio v cc khun y thc hin vic ny. Phi dng cc kch vt thch hp, cc i nm hoc thit b khc ti mi ct :

iu chnh dc gio, cho php iu chnh nh trong khi b tng hoc t kt cu thp phi

quan st ln lch so vi d kin, v xt n vic lng dn ca gio.

Nh thu phi b tr o c chnh xc ln gio trong khi v bo dng b tng. gio hoc vn khun bn mt cu trn cc cu kiu dm phi c trc tip trn cc dm chng khng b ln chnh lch ng k trong khi b tng. Cc dm phi ging v neo chng li cc lc c th lm quay hoc xon trong cc dm do b tng mt cu hoc cc vch ngang hoc phi cho thy l cho cc hiu ng ny. Khng c php hn dm cha gio hoc cc thanh ging vo cc cu kin kt cu thp hoc ct thp, tr khi cho php ring.

3.2.3 Thit k v thi cng vn khun 3.2.3.1 Tng qut Vn khun phi bng g, thp hoc vt liu c chp thun khc, phi kn va v c cng phng xon c hi cho mt b tng c to thnh do p lc ca b tng v cc ti trng khc xy ra trong cc thao tc thi cng. Vn khun dng cho cc mt b tng l ra nhn thy c phi to c mt nhn c cu trc ng u v mu sc c bn ging vi mu sc khi dng g dn chuyn dng. Cc tm lt cc vn khun ny phi b tr sao cho cc ng ni to thnh mt s i xng ph hp vi cc ng nt chung ca kt cu. Phi dng cng mt loi vt liu lt vn khun trong sut mi b phn ca kt cu. Cc vn khun phi cng cho gn sng ca mt b tng khng vt qa 3mm khi kim tra bng mt thc thng hoc dng di 1500 mm. Tt c cc gc nhn phi to vt vi cc di vt cnh khong 20 mm. Khng c b tng vo trong vn khun trc khi mi cng vic lin quan n vic thi cng vn khun hon thnh, cc rc ri, mnh vn c dn sch, tt c cc vt liu chn trong b tng c t vo ch i vi khi c v K s kim tra vn khun v vt liu.


Ch gii: Vn khun ca kt cu b tng dng g dn tham kho Tiu chun sn phm PSI G dn xy dng v cng nghip ca Vin tiu chun v cng ngh quc gia.

3.2.3.2 Thit k Vic thit k kt cu vn khun phi ph hp vi Tiu chun ACI K thut thc hnh nn dng i vi vn khun b tng (ACI 347) hoc Tiu chun khc c chp nhn ph bin. Khi la chn p lc thu tnh s dng thit k vn khun, phi xt n nng sut b tng ln nht, tc ng m rung, nhit b tng v mi cht ph gia lm chm ng kt hoc vt liu puzolan d kin s dng trong hn hp b tng. Ch gii: Thit k vn khun tham kho Thc hnh khuyn dng v vn khun b tng ca ACI 347-78.

3.2.3.3 Thi cng Vn khun phi t v gi chnh xc cc kch thc, cc ng nt v cc dc kt cu trc v trong khi b tng. Vn khun c th lm vt hoc g vin ti cc ch li nh nh tng, m bo d tho. Trc khi s dng li, cc vn khun phi sch, kim tra h hng v phi sa cha nu cn. Khi vn khun c biu hin b hng theo mt kiu no , hoc trc hoc trong khi b tng, K s c th ra lnh dng vic cho n khi ch h hng c sa cha. Vn khun phi x l bi trn bng du vn khun hoc cht tho khun khc c chp thun trc khi t ct thp. Khng c s dng loi vt liu dnh vo hoc lm bin mu b tng. Tr quy nh y, cc thanh ging hoc neo kim loi nm bn trong vn khun phi thi cng th no cho php tho chng ti mt su t nht 25mm t mt b tng m khng lm h hi n b tng. Ch c th dng cc thanh ging bng si thp thng thng khi b tng khng b l ra nhn thy c v khi b tng khng tip xc vi mui hoc sunpht. Cc si thp ging nh vy, khi tho vn khun, phi ct li vo t nht 6mm k t mt b tng bng c hoc km ct; vi b tng ti phi dng km ct. Cc g lp dng cho thanh ging kim loi phi c thit k sao cho khi tho chng, cc l li phi c kch thc nh nht c th. Cc l ny phi nhi va xi mng v b mt li phi tt, nhn, u v mu sc ng u.

Khi yu cu dng ct thp bc epoxy, tt c cc ging, neo hoc tng- kim loi nm li trong b tng phi lm bng loi vt liu chng n mn hoc ph mt cht in mi. Vi cc tng v ct hp, y khun khng th vo c, phi m mt l vo trong vn khun lm sch cc vt liu t bn ngoi vo ngay trc khi b tng.

3.2.3.4 Khun ng

Cc ng dng lm khun to ra l rng trong bn b tng phi c thit k v ch to thch hp hoc c x l lm cho mt ngoi khng thm nc. Trc khi b tng cc ng ny phi c bo v chng g, ct gi v lp t bng cc


phng php khng gy ra mo m h hi. Cc u ca khun ng phi c np y kn va v khng thm nc. Nu dng g hoc cc vt liu khc n ra khi b m lm np ng. phi dng mt vng m bng cao su c sn dy 6mm xung quanh chu vi np cho php dn n. Phi b tr mt ng thng hi PVC gn mi u ca mi ng. Cc ng ny c lm thot hi tt cho cc l rng. Sau khi d khun ngoi, ng thng hi phi c xn li vo trong mt y b tng hon thnh 15 mm. Cc neo v thanh ging cho khun ng phi ng khng b dch chuyn trong khi b tng. 3.2.3.5 Cc vn khun li ti ch Cc vn khun y mt cu li ti ch, nh bng tn ln sng hoc tm b tng c sn, c th c s dng nu c ch r trong h s hp ng hoc c ch dn ca K s. Trc khi dng cc vn khun ny, Nh thu phi cung cp mt b y cc chi tit cho K s xem xt v chp thun. Tr khi c ghi ch khc, cc h s hp ng i vi kt cu cn dng cc vn khun tho ra c. Mi thay i cn thit ph hp vi cc khun li ti ch, nu c chp thun, phi do Nh thu chu chi ph.

3.2.4 Tho d gio v vn khun 3.2.4.1 Tng qut gio v vn khun khng c tho d nu khng c K s chp thun. Khi xc nh thi gian tho gio v vn khun phi xt ti v tr v tnh cht ca kt cu, thi tit, cc vt liu s dng trong m trn v cc iu kin khc nh hng n cng sm ca b tng. Khng c dng cc phng php tho d c kh nng gy ra ng sut qu cao trong b tng hoc gy h hi b mt b tng. Cc ct phi c tho sao cho kt cu chu ng sut do trng lng bn thn ng u v dn dn. Vi kt cu vm c hai hoc nhiu nhp, trnh t tho gio phi theo nh quy nh hoc chp thun trong h s hp ng. 3.2.4.2 Thi gian tho d

Nu cc thao tc hin trng khng c kim tra bng cc th nghim cng b tng theo mu kiu dm hoc mu hnh tr, trc khi tho gio hoc vn khun phi tri qua thi gian ti thiu sau y k t ngy b tng, khng k cc ngy nhit thp di 50C: gio i vi: Khu trn 4300 mm 14 ngy Khu 4300 mm v nh hn 10 ngy M tr khung cha dm 10 ngy Vn khun: Khng trng lng bn thn b tng: 24 gi i vi cc ngn hp bn trong dm hp v i vi lan can: 12 gi

Nu cng c b tng tng nhanh nh dng xi mng loi III hoc s dng thm xi mng, cc thi hn trn c th c gim theo ch dn.


Khi cc thao tc hin trng c kim tra bng cc th nghim mu hnh tr: Ch c tho d cc vn khun chu lc hoc gio sau khi thy b tng

t cng nn quy nh. Khng trng hp no cc ct c tho d trc 7 ngy sau khi b

tng. Vn khun khng c tho trc khi b tng c cng khng

gy ra h hng cho b mt. gio ca cc phn kt cu cng ko sau ch c ni lng sau khi thp

d ng lc c cng ko xong. gio mt nhp bt k no ca mt cu lin tc hoc khung cng ch

c ni lng sau khi cc yu cu ni trn c tho mn i vi tt c b tng kt cu trong nhp v trong cc phn ln cn ca mi nhp k bn vi mt chiu di bng t nht mt na chiu di ca nhp m gio c ni lng.

Tr khi c quy nh hoc chp thun khc trong h s hp ng, gio phi c ni lng trc khi lp lan can, tng nh hoc ro chn cho mi loi cu. Vi cu vm, thi gian ni lng gio so vi thi cng cc b phn ca cu pha trn vm phi c ch ra trn h s hp ng hoc do K s ch dn. 3.2.4.3 Phm vi tho d Tt c gio v vn khun phi c tho d tr:

Cc phn ca cc ng lm gio di lp mt nn trn 300mm trong nn ng, hoc 600 mm di mt t ban u hoc cao hon thin ngoi nn ng, hoc 600 mm di cc gii hn xc nh cho lng knh c chy tu.

Cc vn khun c b mng m khi tho d chng s lm nguy him cho s an ton ca vy hoc cng trnh khc.

Cc vn khun trong cc khoang kn khng c li vo. Cc vn khun mt cu trong cc ngn ca cu dm hp khng cn tr g

n vic lp t cc cng trnh tin ch cng cng nu trong cc h s hp ng.

3.3 VY V KHUNG CHNG

3.3.1 Tng qut vy phi c thi cng ti chiu su thch hp m bo n nh v su bt khng cho nc vo. Chng phi c thit k v thi cng an ton, c lm kn nc cn thit thc hin tho ng cng vic phi lm bn trong . Ni chung, cc kch thc bn trong ca vy phi c khong trng thi cng cc vn khun v kim tra pha ngoi ca chng v cho php bm nc ra ngoi vn khun. vy b nghing hoc b dch ngang do qu trnh h phi nn thng v dch li, hoc lm rng thm to ra khong trng cn thit. Tin chi ph do Nh thu chu. Nh thu phi khng ch nc chy vo sao cho b tng b mng c th thi cng kh. Nh thu phi xc nh c cn lp bt y khng, nu cn th phi xc dnh


chiu dy ca lp bt y v thi gian bo dng cn thit v phi chu trch nhim hon ton v cht lng bt y. Sau khi lp bt c bo dng, vy phi c bm nc ra v phn b tng cn li c thi cng kh. Khi dng vy trng lc v trng lng c dng chng li mt phn p lc thu tnh tc ng vo y lp bt mng, phi b tr neo c bit nh cht hoc kho truyn ton b trng lng vy trong lp bt mng. Trong khi v bo dng lp bt mng, phi kim tra cao nc bn trong vng vy phng nga mi dng chy qua lp bt, nu vy c gi li ti ch, n phi c l thot nc di mc nc thp. Khung chng phi chu c tt c cc ti trng t vo v phi tun th mi quy tc an ton cn p dng. Ch gii: Cc vy v khung chng gm cc kt cu dng gi t tm thi xung quanh v nc ngoi cc h o v bo v ti sn hoc cc cng trnh lin k trong khi thi cng cng trnh vnh cu. Lp b tng bt y ph hp vi yu cu Phn 8 Kt cu b tng phi c di nc di cao mng.

3.3.2 Bo v b tng Cc vy c thi cng bo v b tng ti khi b h hi do dng nc dng ln t ngt v phng nga mng b h hng do xi. Khng c dng cc thanh chng hoc thanh ging hoc cc h chng trong vng vy m vo trong hoc xuyn qua cng trnh chnh m khng c K s cho php bng vn bn.

3.3.3 Tho d Tr khi c quy nh hoc chp thun khc, cc v h chng vi tt c cc cc vn v thanh chng phi tho d sau khi hon thnh kt cu phn di, phi ch khng lm ri hoc h hi cng trnh hon thnh.

3.4 H THNG KHNG CH TM THI MC NC

3.4.1 Tng qut H thng khng ch tm thi mc nc gm c , knh i dng, mng nc v cc cng trnh lm trch dng nc mt khc, h thng tng chn nc v bm, k c h thng ging su v b lc ng kim, dng ngn nc vo trong cc h o cho kt cu.

3.4.2 Bn v thi cng Cc bn v thi cng ca h thng khng ch tm thi mc nc khi cn thit phi bao gm cc chi tit thit k v thit b, phng thc thao tc vn hnh, v v tr im hoc cc im thot nc. Thit k v vn hnh phi ph hp vi tt c cc yu cu kim tra vic nhim bn v xi l ca nc.

3.4.3 Thao tc vn hnh


Vic ht nc ra khi khung vy mng phi loi tr kh nng nc chy qua b tng mi . Khng c ht nc trong khi b tng hoc trong thi gian t nht 24 gi sau , tr khi bm t mt h thch hp tch ring vi cng trnh b tng bng tng kn nc hoc phng php hu hiu khc c K s chp thun. Ch c ht cn nc mt vy bt y sau khi lp bt y cng chu c p lc thy tnh. Bm t cc b lc ng kim hoc cc ging su phi iu chnh trnh lm h hi cho ti sn tip gip do ln st.

3.5 CU TM

3.5.1 Tng qut Cc cu tm phi thi cng, bo tr v tho d sao cho khng lm nguy hi cho cng trnh v dn chng. .

Ghi ch: Cu tm bao gm cc cu i trnh dng cho giao thng cng cng, cu cng v v cc kt cu khc nh cc cu bng ti do nh thu s dng.

3.5.2 Cu trnh Khi c Ch u t cung cp thit k, cu trnh phi thi cng v bo tr theo ng thit k hoc mt phng n thit k khc c chp thun. Khi cc yu cu k thut cho php, Nh thu c th np mt phng n thit k kin ngh. Mi phng n thit k khc phi tng ng v mi mt vi bn thit k v cc s liu do Ch u t cp v phi c K s chp thun. Cc bn v thi cng v cc bn tnh ton cho mi phng n thit k phi do k s chuyn nghip k tn. Khi thit k khng c Ch u t cp, Nh thu phi lp bn thit k v cung cp cc bn v thi cng cho K s xin chp thun. Bn thit k phi cung cp cc khong tnh khng, tuyn, kh nng chu ti v cc thng s tnh ton khc quy nh hoc c chp thun trong h s hp ng. Bn thit k phi ph hp vi Tiu chun thit k cu AASHTO LRFD. Nu khng c quy nh no khc v hot ti thit k, phi dng 75% ca ti trng HL-93. Cc bn v thi cng v cc tnh ton thit k phi do k s chuyn nghip k tn.

3.5.3 Cu cng v Khi kin ngh lm mt cu cng v hoc cc cu khc cho thi cng khng dng cho cng cng vt bn trn mt hnh lang ng cho giao thng cng cng hoc mt ng st, phi np cho K s chp thun cc bn v thi cng vi thit k hon chnh v cc chi tit bao gm c ti trng ln nht phi chu. Cc bn v ny phi do k s chuyn nghip k tn. Bn thit k phi ph hp vi Tiu chun thit k cu AASHTO LRFD khi c th hoc cc Tiu chun thch hp khc. Ch gii: Thit k cu cng v tham kho Tiu chun thi cng cu AASHTO LRFD 2004.


3.5.4 Bo tr Vic bo tr cc cu tm i hi phi c cc bn v thi cng, phi bao gm c vic thay th chng trong trng hp b h hng mt phn hoc ton b. Trong trng hp Nh thu b chm tr hoc tin hnh khng tho ng vic sa cha hoc thay th, Ch u t c quyn cung cp nhn lc, vt liu v gim st cng trnh khi cn khi phc kt cu cho giao thng cng cng c m bo. Ton b chi ph ca vic khi phc v sa cha ny c xem l mt phn ca chi ph cho kt cu tm. Khi Ch u t chi cc khon tin , Nh thu phi gnh chu.

3.6 O C V THANH TON

Tr khi c quy nh khc trong h s hp ng, vic thanh ton cho cng trnh tm c xem l k vo tin thanh ton cho cc hng mc khc nhau ca cng trnh m chng c dng v khng c thanh ton ring. Khi trong bn danh mc hp ng c k n hng mc b tng bit y cho vy, b tng ny c o c v thanh ton nh quy nh trong Phn 8 Kt cu b tng. Khi mt hng mc hoc nhiu hng mc ca cu tm, vy khung chng hoc h khng ch mc nc tnh n trong hng mc b thu, vic thanh ton s l s tin trn gi b thu cho mi kt cu hoc h thng c lit k trong danh mc b thu v c thi cng v tho d theo ng cc yu cu ca h s hp ng. Vic thanh ton ny bao gm vic n b y cho tt c mi chi ph lin quan n vic cung cp mi vt liu, thi cng, bo tr v tho d cng trnh tm .


Ti liu vin dn

AASHTO.1995. Construction Handbook for Bridge Temporary Works, CHBTW-1, American Association of State Highway and Transportation Officials, Washington, DC.

AASHTO. 1995. Guide Desigh Specification for Bridge Temporary, FSBTW-1, American Association of State Highway and Transportation Officials, Washington, DC.

AASHTO. 2004. AASHTO LRFD Bridge Desigh Specifications, 3rd Edition, LRFDUS-3 or LRFDSI-3, American Association of State Highway and Transportation Officials, Washington, DC. Available in customary U.S. units or SI units.

ACI.1978. Recommended Practice for Concrete Framework, American Concrete Institute, Farmington Hills, MI.

FHWA.1991. Synthesis of Falsework, Formwork, and Scaffolding for Highway Bridge Structures, FHWA-RD-91-062, Federal Highway Administration, U.S. Department of Transportation, Washington, DC, Nov. 1991.

FHWA. 1993. Bridge Temporary Works, TS 140.24, Federal Highway Administration, U.S, Department of Transportation, Washington, DC, Oct. 1993.

FHWA.1993. Guide Standard Specifications for Bridge Temporary Works, FHWA-RD-93-031, Federal Highway Administration, U.S. Department of Transportation, Washington, DC, Nov. 1993.

FHWA.1993. Guide Design Specifications for Bridge Temporary Works, FHWA-RD-93-032, Federal Highway Administration, U.S. Department of Transportation, Washington, DC, Nov,. 1993. See also AASHTO GSBTW-1, listed above.

FHWA. 1993. Certification Program for Bridge temporary Works, FHWA-RD-93-033, Federal Highway Administration, U.S. Department of Transportation, Washington, DC, Nov. 1993.

FHWA. 1993. Construction Handbook for Bridge Temporary Works, FHWA-RD-93-034, Federal Highway Administration, U.S. Department of Transportation, Washington, DC, Nov. 1993. See also AASHTO CHBTW-1, listed above.

NIST.1995. Construction and Industrial Plywood, Voluntary Product Standard PS 1-95, National Institute of Standards and Technology, U.S. Department of Commerce, Gaithersburg, MD.

PHN 4: MNG CC NG 4 - 1 -

PHN 4: MNG CC NG MC LC

4.1 M T 4.2 VT LIU... 4.2.1 Cc thp. 4.2.1.1 Sn.. 4.2.2 Cc g. 4.2.3 Cc b tng 4.3 CH TO CC. 4.3.1 Cc b tng c sn. 4.3.1.1 Vn khun... 4.3.1.2 b tng.. 4.3.1.3 Hon thin... 4.3.1.4 Bo dng v bo v 4.3.1.5 To ng sut trc 4.3.1.5.1 Bn v thi cng... 4.3.1.6 Ct gi v bc xp 4.3.2 Cc b tng c ti ch 4.3.2.1 Kim tra ng vch.. 4.3.2.2 b tng.. 4.4 NG CC... 4.4.1 Thit b ng cc... 4.4.1.1 Ba... 4.4.1.1.1 Tng qut. 4.4.1.1.2 Ba ri t do 4.4.1.1.3 Ba hi nc kh nn. 4.4.1.1.4 Ba iden.. 4.4.1.1.5 Ba rung.. 4.4.1.1.6 Thit b hoc cc phng php ph thm.. 4.4.1.2 Cc ph tng ng cc. 4.4.1.2.1 m ba.. 4.4.1.2.2 u truyn ng. 4.4.1.2.3 m cc... 4.4.1.2.4 Gi ba. 4.4.1.2.5 Cc dn

4-3 4-3 4-3 4-3 4-3 4-4 4-4 4-4 4-4 4-4 4-4 4-5 4-5 4-5 4-5 4-5 4-5 4-6 4-6 4-6 4-7 4-7 4-7 4-8 4-8 4-8 4-8 4-8 4-8 4-9 4-9 4-9 4-9


4.4.1.2.6 Xi nc.. 4.4.2 Chun b ng 4.4.2.1 Cng vic cng trng. 4.4.2.1.1 o 4.4.2.1.2 Khoan trc ng cc c d dng 4.4.2.1.3 Cc l khoan trc trong nn ng p.. 4.4.2.2 Chun b cc.. 4.4.2.2.1 ai cc. 4.4.2.2.2 Lm nhn u. 4.4.2.2.3 Thp bt mi cc v vu cc. 4.4.3 ng cc. 4.4.3.1 ng cc th.. 4.4.3.2 chnh xc ng cc. 4.4.4 Xc nh kh nng chu lc. 4.4.4.1 Tng qut 4.4.4.2 Phng php A Cng thc cc kinh nghim. 4.4.4.3 Phng php B Phn tch phng trnh sng........................ 4.4.4.4 Phng php C - Th nghim ti trng ng............................ 4.4.4.5 Phng php D - Th nghim ti trng tnh.............................. 4.4.5 Ni cc 4.4.5.1 Cc thp.. 4.4.5.2 Cc b tng. 4.4.5.3 Cc g. 4.4.6 Cc h hng.. 4.4.7 Ct cc 4.4.7.1 Tng qut 4.4.7.2 Cc g. 4.5 O C V THANH TON 4.5.1 Phng php o c 4.5.1.1 Cc g, thp v b tng 4.5.1.1.1 Cc cp.. 4.5.1.1.2 Cc ng 4.5.1.2 Mi ni cc, chp bt mi cc v vu cc.. 4.5.1.3 Th ti trng... 4.5.2 C s thanh ton.. Ti liu vin dn..

4-9 4-10 4-10 4-10 4-10 4-10 4-10 4-11 4-11 4-11 4-11 4-11 4-12 4-12 4-12 4-12 4-13 4-13 4-14 4-15 4-15 4-15 4-15 4-16 4-16 4-16 4-16 4-17 4-17 4-17 4-17 4-17 4-17 4-17 4-18 4-19


PHN 4 MNG CC NG

4.1 M T

Cng vic ny bao gm vic cung cp v ng cc cc mng thuc chng loi v kch thc ch nh trong h s hp ng, k c vic ct u cc hoc thi cng mng cc khi yu cu. Quy nh cng bao hm c vic cung cp cc cc th nghim v tin hnh cc th nghim ti trng. Cc phi ph hp v c lp t theo Tiu chun ny ng v tr, ng cao , chiu su ng cc v kh nng chu lc cho trn h s hp ng theo ch dn ca K s. Tr khi c yu cu th cc, Nh thu phi cung cp cc cc theo ng cc kch thc cho trong h s hp ng. Khi cn th cc, chiu di cc cho trong h s hp ng ch l c tnh, chiu di thc t cung cp sn xut cc s c K s xc nh sau khi ng cc cc th. Cc chiu di cho trong danh mc t hng ca K s ch gm cc chiu di d tnh dng trong kt cu hon thnh. Nh thu phi tng thm chiu di cho hoc b tng ti ch ni di u cc tng thm chiu di cn thit ph hp vi phng php ng cc ca mnh m khng c n b thm.

4.2 VT LIU

4.2.1 Cc thp

Thp kt cu dng trong cc mng phi ph hp vi Tiu chun AASHTO M 270M/M270 (ASTM A 709/A 709M) cp 36, 50 hoc 50W (cp 250, 345 hoc 345W) hoc ASTM A690/A 690M.

4.2.1.1 Sn

Tr khi c quy nh khc, khi cc thp hoc cc ng vch thp ko di ln trn mt t hoc mt nc, chng phi c bo v bng cc loi sn quy nh cho vic sn thp mi trong mi trng nhim cao hoc vng b bin nh quy nh trong Phn 13 Sn. Vic bo v ny phi lm t cao 600mm di mt nc hoc mt t ti nh ca thp l ra.

4.2.2 Cc g

Cc g phi ph hp vi cc yu cu ca AASHTO M 168. Cc g phi c x l hoc khng x l theo ch dn trong h s hp ng. X l bo qun phi ph hp vi cc yu cu ca Phn 17 X l bo qun g. Phng php ct gi v bc xp phi sao cho khng gy h hi cho cc. Phi c bit ch trnh lm v nt b mt cc x l. Khng c s dng cc mc


xin, ngom hoc thanh xin. Cc ch ct hoc ch v, nt trn b mt cc x l hoc l bu lng phi x l theo quy nh trong iu 16.3.3 G x l.

4.2.3 Cc b tng

Cc b tng gm cc b tng c sn hoc cc b tng c ti ch trong ng vch thp. B tng xi mng Porland phi ph hp vi cc yu cu trong Phn 8 Kt cu b tng, tr khi trong h s hp ng quy nh mt loi khc, b tng phi l loi A. Ct thp phi ph hp vi cc yu cu ca Phn 9 Ct Thp v vic to ng sut trc phi ph hp vi yu cu ca Phn 10 To ng sut trc. Cc ng vch thp dng lm cc b tng c ti ch phi c b dy khng nh hn b dy cho trong h s hp ng. Nh thu phi cung cp cc ng vch c b dy ln hn nu cn thit c cng v cng cho php ph hp vi thit b chn dng m khng lm h hi, v phng nga b vn do p lc t hoc do ng cc cc ln cn. Cc thit k ng vch khc phi c chp thun trc bt k ln h cc no. Cc ng vch cng phi kn nc loi tr nc trong khi b tng. Cc ng vch c th c hnh tr trn hoc cn, hnh cn nhiu bc hoc kt hp c hai vi cc on hnh tr trn.

4.3 CH TO CC

4.3.1 Cc b tng c sn

4.3.1.1 Vn khun

Vn khun cho cc b tng c sn phi ph hp vi cc yu cu chung i vi cng tc vn khun b tng theo quy nh trong Phn 3 Cng trnh tm. Cc khun phi b tr ch a my vo rung v san m b tng.

4.3.1.2 b tng

Vic vn chuyn v b tng phi ph hp vi cc yu cu ca Phn 8 Kt cu b tng v cc quy nh ny. Phi c bit ch b tng sao cho to c lin kt tho ng vi ct thp v trnh vic to thnh cc ti , t ong hoc cc khuyt tt khc. m bo ng u, b tng trong mi cc phi lin tc v phi m cht bng cch rung hoc bng cch khc m K s c th chp thun. Vn khun phi y trn, b tng tha phi gt i, mt trn c hon thin vi mt kt cu ng u, bng phng tng t nh c to thnh bi vn khun.

4.3.1.3 Hon thin


Cc phn cc l ra nhn thy c phi c hon thin theo cc quy nh v vic hon thin ct b tng. Phn cc khc khng phi hon thin, tr phn ni trn y.

4.3.1.4 Bo dng v bo v

Cc b tng phi bo dng theo quy nh trong Phn 8 Kt cu b tng v cc quy nhh ny. Ngay khi cc cng, trnh h hng chng c tho khi khun v xp trong mt chng cc bo dng ngn cch vi nhau bng cc khi g k. Khng c ng cc trc khi b tng cc c t nht 21 ngy tui sau khi c, trong thi tit lnh phi lu hn na theo quy nh ca k s. Cc b tng dng trong nc bin hoc t sunphat phi c bo dng khng t hn 30 ngy trc khi c s dng. B tng phi c bo v khng b ng bng cho ti khi cng nn t t nht 0,8 c.

4.3.1.5 To ng sut trc

Vic to ng sut trc cho cc b tng phi ph hp vi cc quy nh ca Phn 10 To ng sut trc.

4.3.1.5.1 Bn v thi cng Nh thu phi trnh hai b bn v thi cng cc b tng ng sut trc cho K s ti cng trng. Cc bn v ny ghi r kch thc cc, vt liu, phng php to ng sut trc, cch b tr b cp v cc lc to ng sut trc c kin ngh s dng v mi ct thp b tr thm hoc b tr li so vi h s hp ng. Vic thi cng cc ch c bt u sau khi cc bn v c K s chp thun.

4.3.1.6 Ct gi v bc xp

Vic tho vn khun, bo dng, ct gi, vn chuyn v cu lp cc b tng ct thp c sn phi thc hin theo cch no trnh cc ng sut un qa mc, nt v, tch lp hoc cc hu qu lm h hi khc. Phi p dng cc yu cu thit k trong iu 5.13.4 ca Tiu chun thit k cu AASHTO LRFD. Cc cc dng trong nc bin hoc trong t sunfat phi c cu sao cho trnh b mt b mi mn hoc cc tn thng khc l b tng bn trong. Ch gii: Cc yu cu thit k ct gi v cu lp xem iu 5.13.4 Cc b tng trong Tiu chun thit k cu AASHTO LRFD.

4.3.2 Cc b tng c ti ch 4.3.2.1 Kim tra ng vch


mi thi im trc khi b tng trong ng vch, Nh thu phi chun b nh sng kim tra mi ng vch trn sut chiu di ca chng.

4.3.2.2 b tng

Ch c b tng sau khi vic h tt c cc ng vch trong vng bn knh 4500 mm ca cc hon thnh, hoc cng tc h ng vch trong phm v trn phi dng cho ti khi b tng trong cc cui cng c c t nht 5 ngy. B tng trong cc cc c ti ch phi cht ch v ng nht. Thay cho cc quy nh lin quan n vic rung b tng nh quy nh trong iu 8.7.4 m cht b tng, vic rung hoc xc b tng i vi cc cc c ti ch ch yu cu ti sau 1500 mm di mt t. B tng cho mi cc phi theo mt thao tc lin tc duy nht vi dng b tng hng xung di v vo tm cc m b tng bng va p. Nc tch t trong ng vch phi c ht ht trc khi b tng. Sau khi b tng cng, b mt trn cng phi c ct i loi b sa xi mng v l ct liu ra nh quy nh trong Iu 8.8 Mi ni thi cng.

4.4 NG CC

4.4.1 Thit b ng cc

Khng c s dng thit b ng cc lm h hi n cc. Tt c thit b ng cc, bao gm ba ng cc, m ba, u dn, m cc v cc ph tng khc m Nh thu cung cp phi c K s chp thun trc khi ng cc. c chp thun, t nht hai tun trc khi ng cc Nh thu phi np bn m t thit b ng cc cho K s. Mt khi kh nng chu lc ca cc c quy nh phi xc nh theo iu 4.4.4.3 Phng php B-phn tch phng trnh sng, Nh thu cn phi np cc bn tnh da trn phn tch phng trnh sng, chng minh rng cc c th ng vi lc hp l ti chiu di nh m khng b h hi. Phi s dng cc h s c ch ca ba sau y trong phn tch phng trnh sng:

Loi ba H s c ch theo %

Ba n ng kh nn/ hi nc Ba song ng kh nn/ hi nc Ba iden

67 50 72

Ngoi cc quy inh khc ca Tiu chun ny, cc tiu ch m K s dng nh gi thit b ng cc gm c s nht ba cn thit cho mi 300 mm v ng sut cc tng ng vi kh nng chu ti cc hn yu cu ca cc. S nht ba cn thit


theo tnh ton tng ng vi kh nng chu ti cc hn yu cu phi gia 36 v 120 cho mi 300 mm l c th chp nhn c i vi thit b ng cc. Ngoi ra, thit b ng cc c th chp nhn c, ng sut cc tnh ton do thit b ng cc sinh ra khng c vt qu cc gi tr di y:

i vi cc thp, ng sut nn do ng cc khng vt qu 90% gii hn chy ca vt liu cc.

i vi cc b tng, cc ng sut ko khng c vt qu 0,25 nhn vi cn bc hai ca cng nn ca b tng c theo MPa, cng vi gi tr ng sut trc hu hiu, tc 0,25c + ng sut trc, cc ng sut nn khng c vt 85 % cng nn tr i gi tr ng sut trc hu hiu, tc l (0,85c ng sut trc).

i vi cc g, ng sut nn do ng cc khng c vt qu 3 ln cng thit k tnh cho php trong h s hp ng.

Cc chun s ny dng nh gi cc kt qu tnh ton xc nh kh nng c th chp thun c ca thit b ng cc do Nh thu kin ngh. Trong cc thao tc ng cc, Nh thu phi s dng h thng c chp thun. Bt k thay i no trong h thng ng cc ch c xem xt sau khi Nh thu np cc s liu tnh ton thit b ng cc c sa i. Nh thu s c thng bo v s chp thun hay bc b cc thay i h thng ng cc trong vng 7 ngy k t lc K s nhn c yu cu thay i. Thi gian cn thit np, xem xt li, v chp thun mt h thng ng cc c sa i khng c to thnh c s cho nh thu ko di hp ng. Vic chp thun thit b ng cc khng lm gim trch nhim ca Nh thu trong vic ng cc, khng h hng ti kh nng chu nn v cao mi cc cho trong h s hp ng.

4.4.1.1 Ba

4.4.1.1.1 Tng qut Cc c th ng bng ba ri t do, ba kh nn/hi nc, hoc ba iden

ph hp vi cc quy nh ny. Cc ba ng cc, ngoi ba ri t do, phi c kch c cn thit c c nng lng ng cc vi chi khng nh hn 2,5mm mi nht gi tr chu ti yu cu.

4.4.1.1.2 Ba ri t do

Ba ri (trng lc) khng c dng cho cc cc b tng hoc cc cc c kh nng chu ti tnh ton vt qu 30 tn (267000N). Khi cho php dng ba ri t do, trng lng ba khng c nh hn 900kg v chiu cao ri khng vt qu 4500mm. Trong mi trng hp, trng lng u ba ca ba trng lc khng c nh hn tng trng lng ca m ng v cc. Tt c cc ba trng lc phi c


trang b cc thanh dn ba m bo lc va p tp trung vo u ng hoc m cc.

4.4.1.1.3 Ba hi nc kh nn Trng lng phn va p ca cc ba kh nn/hi nc c s dng khng c nh hn 1/3 trng lng cc v m ng, trong mi trng hp trng lng phn va p khng c nh hn 1250 kg. Xng v thit b cung cp cho ba kh nn/hi nc phi c nng lc duy tr, trong cc iu kin lm vic, p lc ti ba do nh sn xut quy nh.

4.4.1.1.4 Ba iden Ba iden u h n ng phi trang b mt dng c cho php k s xc nh s va p ca ba ti mi thi im trong khi ng cc. Ba iden u kn (song ng) phi trang b mt ng h o p lc bung ny, lm vic tt, lp gn mt t k s d dng c c. Nh thu phi cung cp mt th tng quan gia p lc bung ny v nng lng ba cung cp.

4.4.1.1.5 Ba rung Ch c th s dng phng php rung hoc cc phng php ng cc khc khi c quy nh trong h s hp ng hoc bng vn bn ca K s. Tr khi chiu di cc c xc nh t cc cc th ti, kh nng chu lc ca cc ng bng ba rung phi c kim tra bng cch ng li cc u tin ng trong mi nhm 10 cc bng mt ba va p c nng lng ph hp o kh nng ca cc trc khi ng cc cc cn li trong nhm.

4.4.1.1.6 Thit b hoc cc phng php ph thm Trong trng hp su h cc yu cu khng t c bng vic s dng mt ba tun th cc yu cu ti thiu trn y, Nh thu c th phi cung cp mt ba c nng lng ln hn hoc khi cho php cn dng cc phng php ph thm nh xi nc hoc khoan trc.

4.4.1.2 Cc ph tng ng cc

4.4.1.2.1 m ba

Tt c thit b ng cc kiu va p tr ba trng lc phi c trang b m ba vi vt liu m c b dy thch hp ngn nga h hi ba hoc cc v m bo tc ng ng cc ng u. m ba phi lm bng cc vt liu bn, c ch to gi c cc tnh cht ng u trong khi ng. Khng c s dng cc m ba bng g, cp thp v aming. Phi t mt tm va p trn m ba m bo nn ng u vt liu m. m ba phi c kim tra vi s c mt ca K s khi bt u ng cc v sau mi 100 gi ng cc. m ba phi c Nh thu thay th trc khi cho php tip tc ng cc khi b dy m ba b gim qu 25% b dy ban u.


4.4.1.2.2 u truyn ng Cc cc ng vi ba va p phi lp khp vi mt u truyn ng thch hp phn phi nht ba vo u cc. u truyn ng phi c tm thng hng vi tm ba v cc. u truyn ng phi c dn hng bng cc gi ba, khng c lc t do. u truyn ng phi kht vi xung quanh u cc sao cho ngn nga c vic truyn cc lc xon trong khi ng trong lc gi cho ba v cc ng thng hng. Vi cc thp v g, cc u cc phi ct vung v b tr mt u truyn ng gi cho trc dc ca cc thng hng vi trc ba. i vi cc b tng v b tng ng sut trc c sn, u cc phi phng v vung gc vi trc dc ca cc phng nga tc ng lch tm t u truyn ng. Vi cc loi cc c bit, phi b tr cc u truyn ng thch hp, cc cn dn hoc cc dng c khc cc cc c th ng khng b h hi.

4.4.1.2.3 m cc Cc u cc b tng phi c bo v bng mt tm m cc khi tnh cht ca vic ng cc s lm cc h hng qu mc. Khi s dng g dn, b dy ti thiu t trn u cc trc khi ng khng c nh hn 100mm. Phi b tr mt tm m cc mi nu trong khi ng m b nn qu mt na b dy ban u hoc bt u chy. Cc kch thc m ba phi phn phi nht ba trn ton b tit din ngang ca cc.

4.4.1.2.4 Gi ba Phi dng gi ba ng cc cc v ba trong cc v tr ng n trong sut thao tc ng cc. Thanh dn phi thi cng theo cch cho php ba t do chuyn ng trong khi gi thng hng gia ba v cc m bo tc ng ng tm ca mi nht ba. Gi ba phi di khng cn dng cc dn v phi thit k sao cho thng hng vi cc cc xin.

4.4.1.2.5 Cc dn Ch c s dng cc dn khi c K s chp thun bng vn bn hoc khi quy nh trong h s hp ng. Khi cho php dng cc dn, kim tra su h cc sao cho l pht trin kh nng chu lc mong mun ca cc, th cc th nht trong mi tr cu v c mi cc th 10 ng sau phi c lm di v phi ng ton b chiu di khng c cc dn. Cc dn v cc phi c gi v duy tr thng hng trong khi ng. Cc dn phi bng vt liu v kch thc sao cho cc cc c th c ng ti chiu di c xc nh l cn thit trn c s ng cc cc c chiu di. V tr v tim dc cui cng ca hai cc u tin c ng vi cc dn trong mt b mng phi c kim tra xem c ng cc dung sai v v tr quy nh trong iu 4.4.3 ng cc trc khi tip tc ng.

4.4.1.2.6 Xi nc Ch c php xi nc nu c quy nh trong h s hp ng hoc K s chp thun bng vn bn. Khi khng cn xi nc nhng c chp thun sau khi c yu cu ca Nh thu, Nh thu phi xc nh s lng tia xi, th tch v p lc nc cn thit ti vi phun xi d dng t tip gip vi cc m khng lm nh


hng n n nh bn ca cc v tr cui cng. Nh thu phi chu trch nhim v mi h hng ti ch do cc thao tc xi gy ra. Khi trong h s hp ng c quy nh xi nc, thit b xi nc phi c nng lng cung cp vo mi lc mt p lc tng ng vi t nht 0,7 MPa ti hai vi phun 20mm. Trong c hai trng hp, tr khi c quy nh khc ca K s, cc ng phun phi d i khi mi cc trn cao mi quy nh t nht 1500mm v cc phi ng ti kh nng chu lc cn thit bng mt ba va p. Nh thu cng phi kim tra, x l nu cn thit, v b tr tt c nc phun nhm tho mn K s.

4.4.2 Chun b ng cc

4.4.2.1 Cng vic cng trng

4.4.2.1.1 o

Ni chung cc chi c ng sau khi t o xong. Mi vt liu chn gia cc cc phi c ly i ti cao chnh xc trc khi b tng mng.

4.4.2.1.2 Khoan trc ng cc c d dng Khi c quy nh trong h s hp ng, Nh thu phi khoan trc cc l ti v tr cc ti cc chiu su cho trong h s hp ng hoc c K s cho php. Cc l khoan trc phi nh hn ng knh hoc ng cho ca tit din ngang cc v cho php cc thm nhp ti chiu su quy nh. Nu c tr ngi di mt t, nh c cc tng hoc gp cc lp , ng knh l c th tng ti kch thc nh nht lp cc. Mi khong rng cn li sau khi ng cc xong phi lp y ct hoc vt liu khc c chp thun. Vic s dng thun khng c php thay cho vic khoan trc, tr khi c quy nh trong h s hp ng hoc c php bng vn bn ca K s. Vt liu t cc l khoan phi dn i theo chp thun ca K s. Ch gii: Thun l mt thanh cng, ngn ng xung ri rt ln to thnh l t cc vo.

4.4.2.1.3 Cc l khoan trc trong nn ng p Cc cc phi ng qua nn ng mi p phi ng trong cc l khoan sn hoc l thun qua nn ng p khi chiu su ca nn ng p vt qu 1500mm. L phi c ng knh khng nh hn kch thc ln nht ca tit din ngang cc cng 150mm. Sau khi ng cc, khong trng xung quanh cc phi nhi bng ct kh hoc si ht u ti mt t. t ly t cc l khoan phi dn i theo s chp thun ca K s.

4.4.2.2 Chun b cc

Ngoi vic lm vung vn u cc trc khi ng, cc phi chun b thm ng theo quy nh sau y.


4.4.2.2.1 ai cc Khi cn ng cc g c sc chu hn 310.000N hoc khi iu kin ng c yu cu khc, phi b tr cc ai, di hoc dng c khc bo v cc khng b ch hoc x ra.

4.4.2.2.2 Lm nhn u Cc g phi lm nhn u khi iu kin t yu cu. Khi cn thit cc phi bt m cc bng kim loi theo thit k c K s ng , cc u nhn ca cc phi to hnh dng cn thn m bo lc nn ng u trn mi cc.

4.4.2.2.3 Thp bt mi cc v vu cc Thp bt mi cc bo v tt c cc loi cc khi d kin l kh ng v cc vu cc c dng tng kh nng chu lc ca cc thp phi thuc loi cho trong h s hp ng v phi dng ti cc v tr quy nh hoc theo lnh ca K s. Chp bt mi cc bng thp phi ch to t thp c ph hp vi AASHTO M 103M/M 103 (ASTM A 27/A 27M). Cc thp bt mi cc hoc vu cc no c s dng theo la chn ca Nh thu phi c K s chp thun.

4.4.3 ng cc

Cc phi ng ti cc cao mi cc ti thiu v kh nng chu lc cho trn h s hp ng hoc c K s chp thun. Cc cc b chi ln qu 6mm trong khi ng cc cc ln cn th phi ng li.

4.4.3.1 ng cc th

Cc th v cc th ti trng tnh khi c nu trong h s hp ng phi c cung cp theo cc chiu di nh v ng ti cc v tr v ti cao do K s hng dn trc khi cc cc khc trong khu vc cn c vo cc th c lnh ng. Tt c cc cc th phi ng bng ba xung ng (va p) tr khi c quy nh khc trong h s hp ng. Ni chung, chiu di t hng ca cc cc th s ln hn chiu di c tnh ca cc sn xut c th thay i theo iu kin t. Thit b dng ng cc th phi ging ht thit b m Nh thu kin ngh s dng khi ng cc tht. Vic chp thun thit b ng cc phi ph hp vi cc yu cu ca Tiu chun ny. Tr khi c K s cho php lm khc, Nh thu phi o t ti mi cc th ti cao ca y mng trc khi ng cc. Cc th phi ng theo cch m nht ba do K s xc nh ti cao c tnh ca mi cc. Cc th khng t s nht ba quy nh trn y su trn cao mi cc c tnh cho trn h s hp ng 300mm c php hi phc trong mt thi gian t 12 ti 24 gi theo xc nh ca K s trc khi ng li. Khi c th, ba phi khi ng trc khi bt u ng li bng cch ng t nht 20 nht vo cc khc. Nu s nht ba quy nh khng t c khi ng li, K s c th ch th cho Nh thu ng mt phn hoc c chiu di cc th cn li v lp li trnh t hi phc


ng li. Khi theo lnh ca K s, cc cc th ng ti cao ca bn v v khng t c s nht ba yu cu th phi ni v ng cho ti khi t c kh nng chu lc yu cu.

4.4.3.2 chnh xc ng cc

Cc cc phi ng vi sai lch khng qu 1:50 theo trc cc thng ng hoc theo trc cc xin cho trong h s hp ng, tr cc cc dng lm tr gio phi ng sao cho m cc c th t vo ng v tr m khng gy ra tc ng xu ln sc chu ti ca cc cc. Cc cc mng sau khi ng khng c lch khi v tr cho trong h s hp ng qa 25% ng knh cc hoc 150mm, ly s no ln hn. Mi ph tn do tng kch thc mng hoc tng ct thp do cc cc b lch khi v tr phi do Nh thu chu.

4.4.4 Xc nh kh nng chu lc

4.4.4.1 Tng qut

Cc cc phi ng ti kh nng chu lc cho trn h s hp ng. Kh nng chu lc ca cc s do K s xc nh nh quy nh trong h s hp ng bng cch s dng mt hoc mt t hp ca cc phng php sau. Phng php A, Cng thc cc kinh nghim s c s dng khi khng c cc quy nh khc trong h s hp ng.

4.4.4.2 Phng php A Cng thc cc kinh nghim

Khi khng ng ti chi theo thc hnh, kh nng chu lc nhn h s ca cc s c xc nh bng cng thc cc kinh nghim. Tr khi c quy nh khc trong h s hp ng, c th dng cng thc sau y: Vi ba ri t do (trng lc)

Pn = (0,6)1635

( 25)WH

S + (4.4.4.2-1)

Vi cc loi ba khc

Pn = (0,6)166,7

( 2,5)E

S + (4.4.4.2-2)

Trong : Pn : kh nng chu lc cha nhn h s, hay danh nh, N W : trng lng ca phn va p ca ba, kg H : chiu cao ri, m E : nng lng do mi nht ba sinh ra, J. Gi tr da trn nht ba thc t

hoc p lc bung ny quan st c (ba iden song ng),


S ; d xung su trung bnh tnh theo mm ca 5 ti 10 nht ba cui cng i vi ba trng lc v 10 n 20 nht ba cui cng i vi cc loi ba khc. Cc cng thc trn ch p dng c khi :

Ba c ri t do (ba trng lc v ba n ng). u cc khng b x ra, v vn hoc b cc h hi khc. xung su (thm nhp) nhanh hp l v ng u. ny tr li khng ng k. Khng dng cc dn.

xung su theo nht ba c th o trong ln ng u tin hoc trong ln ng li vi mt ba khi ng trc vi nng lng sau mt thi gian cc n nh, theo xc nh ca K s. Trong trng hp dng tia nc xi kt hp vi ng cc, kh nng chu lc c xc nh bng cng thc trn t cc kt qu ng cc sau khi khng xi nc na.

Ch gii: Cng thc k lc mi v cng trnh ENR c sa dng cho ti trng nhn h s bng cch nhn vi tng cc ti trng nhn h s v chia cho tng cc ti trng cha nhn h s. y khng phi l s hiu chnh thng k v do khng th hin bt k s ci thin no v tnh khng chnh xc ni ting ca phng trnh ENR. H s sc khng dng cho cc phng trnh ENR ph thuc vo phng php c dng xc nh sc khng a k thut ca cc chu ti dc trc. H s 0,8 l s trit gim tip theo ch dng khi s dng cng thc ENR.

H s 0,6 l xt n s khc bit truyn thng gia bin an ton gi nh trong thit k v quy nh truyn thng trong Phn II ca Tiu chun cu.

Phn ny cn hay dng t K s-lp-bin bn (Engineer-of-Record) nn b i v nhim v caT vn gim st Vit Nam l phi lp bin bn ri.

4.4.4.3 Phng php B Phn tch phng trnh sng

Khi c quy nh trong h s hp ng, kh nng chu lc cc hn ca cc c xc nh bng vic phn tch phng trnh sng. Cc tnh cht ca t, cc v thit b ng cc s dng trong phn tch ny dc cho trong h s hp ng, hoc theo xc nh ca K s bng cch s dng cc s liu do Nh thu cung cp, cc l khoan th nghim v khi s dng cc th nghim ng lc cc (Phng php C). Kh nng chu lc ca mt cc phi ly bng 85% kh nng chu lc cc hn tnh ton ch ly theo phn tch pbng trnh sng cho mt mc thm nhp cho trc. Khi kh nng chu lc cc hn c xc nh t phn tch phng trnh sng c hiu chnh t cc kt qu th nghim ng lc cc th kh nng chu lc cha nhn h s hoc danh nh phi ly bng kh nng chu lc cc hn tnh ton c t phn tch phng trnh sng cho mc thm nhp cho trc.

4.4.4.4 Phng php C - Th nghim ti trng ng


Cc o c ng lc phi do k s lm trong khi ng cc cc gi l cc th nghim ti trng ng. Kh nng chu lc cc hn ca cc s c xc nh vi vic s dng cc dng c phn tch cc v kt qu ny c coi l sc khng danh nh. Trc khi t ln gi ba, Nh thu phi chun b cho mi cc b tng v /hoc cc g c ch nh c th ly c cc s liu o c tc sng v phi khoan sn vo cc cc l gn thit b o cn thit. Khng cn ly cc s liu o c tc sng trc khi ng cc thp. Khi o c tc sng, cc phi t v tr nm ngang cch khi mt t v khng tip xc vi cc khc. K s s cung cp thit b, vt liu v nhn lc cn thit khoan cc l trn cc lp cc thit b. Nh thu phi lp cc thit b vo cc sau khi cc t trn gi ba, hoc cung cp cho K s cc phng tin hp l ti c cc lp cc thit b sau khi cc dng trn gi ba. Nh thu phi cung cp sn c kch thc ti thiu 1200x1200mm (1,44m2) c thit k nng c ti nh cc trong khi cc nm trn gi ba. Nh thu phi cung cp in cho thit b th nghim ng lc. in xoay chiu cp ti cm phi l in 10A, 115 vn, 55-60 chu k. Cc my pht in hin trng dng lm ngun in phi c trang b ng h o gim st cc mc in th v tn s. Nh thu phi cung cp mt bung nh bo v thit b th nghim ng lc. Bung bo v phi c kch thc sn ti thiu 2400x2400mm (5,76m2) v mt mi che cao ti thiu 2100mm. Nhit trong bung phi duy tr trn 70C. Bung phi t cch v tr th nghim trong vng 15000mm. Nh thu phi ng cc ti sau ti thit b th nghim ng lc cho bit t c kh nng chu lc thit k cho trong h s hp ng, tr khi c ch th khc ca K s. Nu K s ch th, Nh thu phi gim nng lng ng truyn cho cc bng cch dng thm cc m hoc gim nng lng ra ca ba duy tr cc ng sut c th chp nhn c trong cc. Nu cc s o ca thit b th ng lc cho thy ng khng ng tm cc, Nh thu phi ngay tc khc chnh li h thng ng cc cho thng hng. Khi K s ch th, nh thu phi i ti 24 gi sau khi thit b li c gn vo, ng li cc th nghim ti trng ng. Ba phi khi ng trc khi bt u ng li bng cch ng t nht 20 nht vo cc cc khc. Yu cu cc xuyn xung ti a khi ng li phi l 150mm hoc tng nht ba ti a bng 50, ly trng hp no xy ra trc. Sau khi ng li, K s s cung cp cao ct u cc hoc quy nh ng su thm v th nghim thm.

4.4.4.5 Phng php D - Th nghim ti trng tnh

Th nghim ti trng phi tin hnh theo cc phng php xut trong ASTM D 1143 bng cch s dng phng php th nghim nn nhanh ti trng tr khi phi th nghim ti lc ph hoi ln st hoc ba ln ti trng thit k, ly trng hp no xy ra trc. Thit b th nghim v h thng o phi ph hp vi ASTM D 1143. Nh thu phi np cho K s chp thun h s hp ng chi tit v dng c cht ti kin ngh do k s chuyn nghip chun b. Dng c phi c ch to cho php tng dn cc ti trng khc nhau m khng lm rung cc th. Khi phng php th nghim yu cu s dng cc cc chu ko (neo) sau c s dng nh cc vnh


cu trong cng trnh, cc cc chu ko ny phi cng loi v ng knh nh cc cng trnh v phi ng v tr cc vnh cu khi c th. Kh nng chu lc danh nh phi ly bng ti trng ph hoi. Ti trng ph hoi ca mt cc th nghim chu nn dc trc l ti trng to ra ln lc ph hoi u cc bng: Sf = S + (3,8 + 0,008D) (4.4.4.5-1) Trong : Sf = ln lc ph hoi, mm D = ng knh hoc b rng cc, mm S = bin dng n hi ca tng chiu di cc khng c chng , mm Cao nh cc th nghim phi xc nh ngay sau khi ng v ngay trc khi th ti kim tra nng ln ca cc. Cc no b nng ln qu 6mm phi ng li hoc kch cho v cao ban u trc khi th nghim. Tr khi c quy nh khc trong h s hp ng, phi quan st mt thi gian ti thiu l ba ngy gia lc ng mt cc neo no hoc cc th ti v lc bt u th ti.

4.4.5 Ni cc

4.4.5.1 Cc thp

Phi s dng cc c chiu di khi c th. Nu cho php ni, phng php ni phi c quy nh trong h s hp ng hoc c K s chp thun. Nn dng phng php hn h quang khi ni cc cc thp. Ch cc th hn c cp chng ch mi c hn.

4.4.5.2 Cc b tng

Cc b tng khng c ni, ngoi cc on ni ngn cho php y, tr khi c quy nh trong h s hp ng hoc bng vn bn ca K s. Cc on ni ngn c th thm vo nh cc cc b tng ct thp sa li cc trng hp khng d on trc. Sau khi ng xong, b tng u cc phi ct b, li ct thp l ra mt on di bng 40 ng knh. Mt ct cui cng ca b tng phi vung gc vi trc cc. Phi buc chc chn ct thp tng t ct thp dng trong cc vo on thp th ra v t vn khun cn thit, ch cn thn phng nga r r dc theo cc. Cht lng b tng khng c km cht lng b tng dng trong cc. Ngay trc khi b tng, u cc phi xi nc k, cho kh, sau ph mt lp mng xi mng, va hoc vt liu dnh kt ph hp. Vn khun phi gi ti ch t nht by ngy, sau c tho cn thn v ton b b mt l ra ca cc phi c hon thin nh quy nh phn trc.

4.4.5.3 Cc g


Cc g khng c ni tr khi c quy nh trong h s hp ng hoc bng vn bn ca K s.

4.4.6 Cc h hng

Phng php ng cc khng c lm dng qu mc v sai phm qu ng lm cho b tng b v v nt, b nt n c hi, g b v v x ra, hoc thp b bin dng qu mc. Khng c php kch p cc dch vo ng v tr nu K s cho rng vic dch l qu ng. Bt c cc no b h hng do cc khuyt tt bn trong, hoc do ng khng ng cch hoc ng lch khi v tr ng ca n, hoc ng thp hn cao u cc c h s hp ng hoc K s quy nh u phi sa cha li bng chi ph ca Nh thu theo mt trong cc cch c s chp thun ca K s i vi cc c vn di y:

Phi rt cc ln v thay bng cc mi, nu cn, l mt cc di hn. ng mt cc th hai k vi cc b h hng hoc cc b thp. Cc phi ni hoc c di thm theo quy nh khc y hoc mt phn

mng c m rng chn cc ng cch.

Tt c cc cc b y ln do ng cc cc ln cn hoc do bt c nguyn nhn g cng phi ng xung li. Tt c cc vt liu v cng vic sa cha phi do Nh thu cung cp vi khon chi ph ca h.

4.4.7 Ct cc

4.4.7.1 Tng qut

Tt c cc cc phi ct mt mt phng ng vi cao yu cu v neo vo kt cu nh cho trong h s hp ng. Tt c cc on cc ct b thuc v ti sn ca Nh thu v phi thu dn tho ng.

4.4.7.2 Cc g

Cc cc g m g hoc i cc phi ca theo ng mt phng y kt cu chng bn trn. Ni chung, chiu di cc trn cao ct b phi cho php loi b hon ton mi vt liu b h hng do ng cc, nhng cc ng ti rt gn cao ct phi b vo hoc loi b bng cch khc tt c cc vt liu b x, v hoc b h hi khc mt cch thn trng. Ngay sau khi ct ln cui cng cc cc g c x l ca mng, din tch ct phi qut kn hai lp cht bo qun, sau l mt lp dy c hc n trn ph xi mng hoc cht bt c chp thun khc. Cc g x l c cc ch ct l ra trong kt cu th din tch ct phi x l bng ba lp vt liu bo qun ph hp.


Ch gii: Bo qun cc g tham kho Tiu chun gi gn g x l bo qun M4 ca Hip hi bo qun g.

4.5 O C V THANH TON

4.5.1 Phng php o c

4.5.1.1 Cc g, thp v b tng

4.5.1.1.1 Cc cung cp Khi lng ca mi loi cc c thanh ton s l tng s chiu di tnh bng mt ca cc cc. Cc phi l loi hnh v chiu di c ghi trong h s hp ng hoc c K s cho dng bng vn bn, c cung cp ph hp vi cc yu cu v vt liu theo Tiu chun ny v c ct gi, i vi cc cc b tng c ti ch h xong, trng thi tt ti a im cng trnh v c K s chp thun. Chiu di ca cc cc, k c cc th do Nh thu cung cp thay th nhng cc trc y c K s chp thun nhng sau b h hng trc khi hon thnh hp ng khng c tnh vo khi lng thanh ton. Khi cn ni thm cc, chiu di ni thm theo lnh bng vn bn ca K s c tnh vo trong chiu di cc cp.

4.5.1.1.2 Cc ng Khi lng cc ng ca mi loi c thanh ton l s lng cc chp nhn c ca mi loi cc ng. Vic khoan trc, xi nc hoc cc phng php khc lm d dng cho vic ng cc, khi c yu cu hoc c php s khng c tnh khi lng v vic thanh ton phi xt tnh vo trong n gi thanh ton cho cc cc ng.

4.5.1.2 Mi ni cc, chp bt mi cc v vu cc

Khi trn h s hp ng c nu cc mi ni cc, cc chp bt mi cc bo v hoc cc vu ct t, s lng mi ni, chp bt v vu cc o thanh ton l s lng cho trn h s hp ng hoc theo lnh bng vn bn ca K s, v thc t lp trn cc dng cho cng trnh. Khng thanh ton cho cc mi ni, chp bt v vu cc c dng theo phng n ca Nh thu. Khi khng c nu trong h s hp ng, cc mi ni, chp bt hoc vu do K s ra lnh s c thanh ton theo cng vic lm thm.

4.5.1.3 Th ti trng

Khi lng th ti trng c thanh ton l s lng th nghim ti trng hon thnh v c chp thun, tr cc th nghim ti trng c lm theo ca Nh thu khng c k vo khi lng o c thanh ton.


Cc cc neo v cc th lm th nghim ti trng, d c nm trong cng trnh vnh cu hay khng, c tnh nh cc cc cung cp v ng v c thanh ton theo hng mc thch hp.

4.5.2 C s thanh ton

Cc khi lng c xc nh nh quy nh, c thanh ton theo n gi trong h s hp ng cho n v o c tng ng cho tng loi, vi mi loi hng mc thanh ton chung lit k di y i vi mi kch thc v loi cc cho trong h s hp ng:

Hng mc thanh ton n v thanh ton

Cc cp Cc ng Cc th cp Cc th ng Th ti trng cc (tnh) Th ti trng cc (ng) Mi ni Chp bt Vu cc

Mt di Ci

Mt di Ci Ci Ci Ci Ci Ci

Vic thanh ton cho vic cung cp cc bao gm mi chi ph lin quan trong vic cung cp v giao cc, k c ng vch cho cc cc c ti ch, ti cng trng v tt c cc chi ph lin quan n vic cung cp v c b tng v t ct thp i vi cc cc c ti ch. Vic thanh ton cho vic ng cc phi n b y cho mi chi ph lin quan trong vic ng v ct thc s cc cc v ng vch, v cho tt c cc chi ph cha c n b trong cc hng mc thanh ton khc lin quan ti vic cung cp nhn lc, thit b v vt liu dng thi cng cc cc nh cho trn h s hp ng. Khi vic huy ng my mc v thit b cho d n khng c thanh ton ring, vic thanh ton cho vic ng cc cng phi k n vic n b y cho chi ph huy ng tt c cc thit b cn thit bc d v ng cc sau khi cc cc c giao ti cng trng. Vic thanh ton cho cc th nghim ti trng bao gm vic n b y cho vic cung cp nhn lc, thit b v vt liu cn thit cho vic thc hin cc th nghim ti trng nh quy nh. Vic thanh ton theo cc hng mc chi tr thch hp i vi cc mi ni cc, cc chp bt v vu cc bao gm vic n b y cho tt c cc chi ph lin quan n vic cung cp tt c vt liu v thc hin cng vic bao gm vic gn vo hoc lp t cc mi ni, cc chp bt v vu vo cc.


Ti liu vin dn

AASHTO. 2002. Standard Specifications for Highway Bridge, 17th Edition, HB-17, American Association of State Highway and Transportation Officials, Washington, DC.

AASHTO. 2004. AASHTO LRFD Bridge Design Specifications, 3rd Edition, LRFDUS-3 or LRFDSI-3, American Association of State Highway and Transportation Officials, Wahington, DC. Available in customary U.S. units or SI units.

AASHTO. 2004. Standard Specifications for Transportation Materials and Methods of Sampling and Testing, 24th Edition, HM-24, American Association of State Highway and Transportation Officials, Washington, DC.

AWPA. 2002. Standard for the Care of Preservative- Treated Wood Products, AWPA-M4-02, American Wood-Preserverss Association, Selma, AL.

Engineering News-Record formula. Based on a formula published in 1888 by A.M. Wellington, editor of Engineering News-Record, New York, NY.

PHN 5: CC KHOAN V GING KHOAN 5 - 1 -

PHN 5: CC KHOAN V GING KHOAN MC LC

5.1 M T 5.2 BN V THI CNG. 5.3 VT LIU... 5.3.1 B tng 5.3.2 Ct thp.. 5.3.3 ng vch 5.4 THI CNG. 5.4.1 Bo v cc kt cu hin c.. 5.4.2 Trnh t thi cng 5.4.3 Cc phng php v thit b chung... 5.4.4 Phng php thi cng kh.. 5.4.5 Phng php thi cng t.. 5.4.6 Phng php thi cng ng vch tm thi. 5.4.7 Phng php thi cng ng vch vnh cu 5.4.8 Cc phng php thi cng khc 5.4.9 Cng tc o.. 5.4.10 ng vch.. 5.4.11 Va khoan 5.4.12 Kim tra l khoan o 5.4.13 Thi cng v t lng ct thp 5.4.14 b tng, bo dng v bo v b tng. 5.4.15 Cc th v cc m rng chn. 5.4.16 Dung sai thi cng ... 5.4.17 Th nghim tnh ng nht.. 5.5 CC TH NGHIM TI TRNG CC KHOAN. 5.6 O C V THANH TON 5.6.1 o c. 5.6.1.1 Cc khoan... 5.6.1.2 Mng m rng chn...... 5.6.1.3 Cc th 5.6.1.4 Phn m rng th nghim... 5.6.1.5 Thm d..

5-3 5-3 5-3 5-3 5-4 5-4 5-4 5-4 5-4 5-4 5-5 5-5 5-5 5-6 5-6 5-6 5-6 5-7 5-8 5-8 5-8 5-9 5-9 5-10 5-10 5-11 5-11 5-11 5-11 5-11 5-11 5-11


5.6.1.6 ng vch vnh cu 5.6.1.7 Th ti. 5.6.2 Thanh ton. 5.6.2.1 Cc khoan.. 5.6.2.2 Mng m rng chn.. 5.6.2.3 Cc th 5.6.2.4 Phn m rng th nghim.. 5.6.2.5 L thm d.. 5.6.2.6 ng vch vnh cu 5.6.2.7 Th ti.

5-11 5-12 5-12 5-12 5-12 5-12 5-12 5-12 5-13 5-13


PHN 5 CC KHOAN V GING KHOAN

5.1 M T

Cng vic ny bao gm vic thi cng cc cc khoan v ging khoan, c hoc khng c mng loe, k c vic t ct thp v b tng theo ng cc h s hp ng v cc quy nh ny.

Ch gii: . Trong phn ny thut ng cc c ngha l cc hoc ging.

5.2 BN V THI CNG

Khi h s hp ng yu cu, t nht bn tun l trc khi bt u cng vic khoan cc, Nh thu phi np cho K s xem xt v chp thun k hoch thi cng cc khoan. H s np phi bao gm:

Danh mc thit b ngh s dng, gm cn cu, my khoan, mi khoan, thng vt bn, thit b lm sch sau cng, thit b lc ct, bm va st, thit b ly mu, cc phu hoc cc bm b tng, ng vch vv

Trnh t chi tit thao tc thi cng chung v trnh t thi cng cc khoan trong cc tr khung hoc nhm cc.

Chi tit cc phng php thi cng cc khoan. Khi cn n va st, chi tit ca phng php kin ngh trn, lun

chuyn v lc ct trong va st. Chi tit cc phng php lm sch h khoan. Chi tit t ct thp k c cc phng php v t ng tm. Chi tit b tng, bo dng v bo v. Chi tit mi th nghim ti trng yu cu. Thng tin khc cho trn h s hp ng hoc do K s yu cu.

Nh thu ch c bt u thi cng cc cc khoan sau khi cc bn v thi cng ca chng c K s chp thun. Vic chp thun ny khng gim nh trch nhim ca Nh thu v cc kt qu t c do s dng cc bn v ny hoc bt k trch nhim no khc ca Nh thu theo h s hp ng.

5.3 VT LIU

5.3.1 B tng

B tng phi ph hp vi cc yu cu ca Phn 8 Kt cu b tng. B tng phi l loi A tr khi c quy nh khc trong h s hp ng.


5.3.2 Ct thp

Ct thp phi ph hp cc yu cu ca Phn 9 Ct thp.

5.3.3 ng vch

ng vch no c coi l mt phn ca cng trnh vnh cu phi ph hp vi cc yu cu ca Phn 11 Kt cu thp. Thp phi l loi AASHTO M270M/M270 (ASTM A709/A 709M) cp 36 (cp 250) tr khi c quy nh khc trong h s hp ng.

5.4 THI CNG

5.4.1 Bo v cc kt cu hin c

Phi dng mi cch phng nga hp l phng h hng cho cc kt cu hin c v cng trnh tin ch cng cng. Cc bin php ny phi bao gm, nhng khng ch hn ch vic la chn cc phng php thi cng v cc phng thc ngn nga vic ln st qu mc khi ly t trong cc, gim st v kim tra cc rung ng do h cc ng vch hoc cc vn, khoan cc hoc do n mn nu c php.

5.4.2 Trnh t thi cng

Mi vic o mng trong cc cc khoan c thi cng phi hon thnh trc khi vic thi cng cc bt u. Tr khi h s hp ng quy nh khc, ni no cc khoan c thi cng cng vi vic p nn ng, chng phi thi cng sau khi p t.

5.4.3 Cc phng php v thit b chung

Phi tin hnh o theo yu cu ca cc khoan v mng loe xuyn qua bt c loi t no gp phi, theo cc kch thc v cao cho trn h s hp ng hoc theo lnh ca K s. Cc phng php v thit b s dng phi ph hp vi cc mc ch nh lm v t phi gp. Ni chung, thng dng phng php kh, phng php t, phng php ng vch tm thi, phng php ng vch vnh cu tu theo cn thit to ra cc mng b tng tt, bn khng c khuyt tt. Phng php ng vch vnh cu ch dng khi h s hp ng yu cu hoc c K s cho php. Khi h s hp ng yu cu mt phng php thi cng no , phi s dng phng php . Nu khng quy nh phi dng phng php no, Nh thu phi la chn v s dng phng php cn thit hon thnh tt cng trnh tu theo cc iu kin ti ch v c K s chp thun.


5.4.4 Phng php thi cng kh

Ch c dng phng php thi cng kh ti cc a im m mc nc ngm v cc iu kin a im ph hp cho php thi cng cc trong h o tng i kh, v khi mt bn v chn ct n nh v c th kim tra bng mt trc khi b tng. Ch gii: Phng php kh gm c khoan h ct, rt nc tch t v loi b vt liu ri rc khi h o, b tng cc trong h o tng i kh.

5.4.5 Phng php thi cng t

Phi s dng phng php thi cng t ti cc a im m cch o kh khng th duy tr b tng cc. Phi b tr cc ng vch tm thi trn b mt gip cho vic nh v v tr v tuyn cc, ngn nga nh h o b st, tr khi chng minh c cho K s tho mn l khng cn n ng vch trn mt. Ch gii: Phng php ny gm c vic s dng nc hoc va khong duy tr n nh ca chu vi l trong khi tin hnh o ti su cui cng, t lng thp v b tng. Phng php ny c th yu cu loi b ct v lm sch va st; lm sch cui cng l o bng gu tt, my ht kh nn, bm t chm hoc cc thit b khc; b tng cc vi mt ci phu hoc bm b tng.

5.4.6 Phng php thi cng ng vch tm thi

Phi dng phng php thi cng ng vch tm thi ti cc a im m cc phng php thi cng kh hoc t khng thch hp. Nh mt phng n khc ca phng php o t, ng vch tm thi c th t bng cch ng hoc rung trc khi o ti cc gii hn cao thp hn lp t st. Trc khi rt ng vch v trong khi ang rt ng vch, cao b tng ti trong ng vch phi cao sao cho mi cht lng tp trung sau ng vch c dch chuyn ln trn m khng lm bn b tng cc. Ch gii: phng php ny gm c vic tin hnh o qua lp t d st bng phng php t nh m t trong iu 5.4.5 Phng php thi cng t. Khi o ti mt lp gn nh khng thm nc, t mt ng vch trong l v kht kn trong lp gn nh khng thm nc. Sau khi dung dch khoan b ht i khi ng vch, c th tin hnh khoan theo phng php kh tr khi ng vch phi rt ln khi b tng cc. nu tnh hnh nc r ngn cn vic s dng phng php kh, vic o phi hon thnh theo phng php t. C th b va st nu c th t ng vch m ch gy ra st rt nh trong l.


5.4.7 Phng php thi cng ng vch vnh cu

Phi dng phng php thi cng ng vch vnh cu khi h s hp ng yu cu. Nu khng th h chiu su thm nhp, K s c th yu cu o t trong phn chn ngp ca ng vch hoc o mt l dn di chn ng vch cho ti khi ng vch t thm nhp cn thit. Trong mt s trng hp c th cn n vic khot rng thm ng knh ngoi ca ng vch a ng vch xung. ng vch phi lin tc gia cc cao cho trn h s hp ng. Khng c dng ng vch tm thi thay cho hoc thm vo ng vch vnh cu, tr khi quy nh trong h s hp ng hoc cho php bng vn bn ca K s. Sau khi t ng vch v o cc xong, ng vch phi ct ti cao quy nh, t ct thp v b tng vo trong phn ng vch li ti ch. Ch gii; Phng php ny gm c vic ng hoc xoay mt ng vch ti chiu su quy nh trc khi vic o bt u.

5.4.8 Cc phng php thi cng khc

Nh thu c th ngh cc phng php thi cng khc ngn nga t st v khng ch nc ngm. Cc kin ngh ny phi np theo iu 5.2 Bn v thi cng km theo cc s liu chng minh.

5.4.9 Cng tc o

Cao y ca cc khoan cho trn bn v c th iu chnh trong thi cng nu K s xc nh rng t nn gp phi trong khi o khng ph hp hoc khc vi loi t d kin trong thit k cc khoan. Nh thu phi ly cc mu t hoc li khi c nu trong h s hp ng hoc theo ch dn ca K s xc nh tnh cht t trc tip bn di h o. K s s kim tra cc mu hoc li t xc nh su yu cu cui cng ca h o cc khoan. t o ly ra khi l khoan v mi dung dch khoan phi dn b theo h s hp ng hoc theo ch th ca K s. Khi trn h s hp ng c nu dn cc mng loe, chng phi c o to thnh mt din tch chu nn c kch thc v hnh dng cho. Ming loe phi o bng phng php c gii.

5.4.10 ng vch

ng vch phi bng kim loi, nhn, sch, kn nc v c d cng chu c cc ng sut khi cu v khi ng v chu c p lc ca c b tng v ca cc loi t xung quanh. ng knh ngoi ca ng vch khng c nh hn kch thc quy nh ca cc.


Phi rt cc ng vch tm thi ln khi b tng cn cha ng cng. Ni chung, vic rt ng vch tm thi ch c bt u sau khi b tng trong cc ti mt t hoc trn mt t. c php lm ng vch c th chuyn ng bng cch quay, tc ng p lc xung v v d rt ln hoc rt bng ba rung. Vic rt ng vch phi lm vi tc chm, vi lc ko ng u theo trc dc. Phi duy tr mt ct b tng bn trn y ng vch thng c p lc thu tnh ca nc hoc dung dch khoan bn ngoi ng vch.

5.4.11 Va khoan

Va trong qu trnh khoan phi l loi va khong, va phi c c ht khong cht l lng vi cc c trng nht v keo vn chuyn t o ti h thng phn loi ph hp. T l phn trm v trng lng ring ca vt liu dng lm cht l lng phi duy tr n nh ca l o v cho php b tng ng n. Cao va phi duy tr ti mt chiu cao phng nga l b st. Va khong phi trn k trc vi nc ngt sch v vi thi gian cho vic hydrat ho trc khi a vo trong l o. Phi cn n cc thng cha va thch hp khi c quy nh. Khng c php lm cc h cha va khi c yu cu thng cha va trong d n, tr khi c php bng vn bn ca K s. Khi c quy nh trong h s hp ng phi c thit b loi b ct thch hp. Phi c cc bin php ngn chn va b ng cng trong l cc, nh khuy, tun hon hoc iu chnh cc tnh cht ca va. Nh thu phi tin hnh cc th nghim kim tra bng cc dng c ph hp i vi va khong xc nh t trng, nht v pH. Trong bng sau cho phm vi c th chp nhn c ca cc gi tr i vi cc tnh cht vt l ny.

Bng 5.4.11-1 Phm vi cc gi tr 20oC

Tnh cht, n v lc a va vo lc b tng trong l

Phng php th nghim

T trng (kg/m3) 1030 -1110 1030 - 1200 Cn t trng nht (S/L) 30 48 30 48 Hnh nn pH 8 11 8 11 Giy hoc thc

o pH

Cc chun s sau y dng cho Bng 5.4.11-1 Tng gi tr t trng thm 32 kg/m3 trong nc mn. Nu cn loi b ct; hm lng ct khng c vt qu 4% (theo th tch)

bt c im no trong l o xc nh theo th nghim hm lng ct ca Vin Du m M.


Cc th nghim xc nh cc gi tr t trng, nht v pH phi lm trong khi o l cc xc nh kiu lm vic ph hp. Trc khi b tng cc, cc mu va phi ly t y v ti cc khong cch khng qu 3000mm trn ton b chiu cao va. Mi phn va b nhim bn nng tch t y cc phi loi b. Va khong phi trong phm v cc yu cu k thut ngay trc khi b tng.

5.4.12 Kim tra l khoan o

Nh thu phi cung cp thit b kim tra cc kch thc v thng ca mi l cc. Cc kch thc v thng phi do Nh thu xc nh c s ch dn ca K s. Chiu su cui cng ca cc phi c o sau khi dn sch ln cui. L cc khoan phi dn sch s ch cn khng qu 1

2010.07.12 Tccs 02.2010-Tcdbvn Tieu Chuan Tc Cau Duong Bo Aashto

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Transcript of 2010.07.12 Tccs 02.2010-Tcdbvn Tieu Chuan Tc Cau Duong Bo Aashto