tc cong trinh bvbb-01

TRng i hc xy dngVIN XY DNG CNG TRNH BIN

BI GINGBI GINGBI GINGBI GINGkk thutthut TThi hi cngcng CT BO V CT BO V BB BINBIN

((titi liuliu lulu hnhhnh nini bb))

Bin son: Ths. Nguyn Quang To

H NI H NI 20122012

B mn C s k thut CTB&CT Ven bin Bi ging: K thut TCCT bo v b bin

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CHNG 1. THI CNG SAN NN VEN BIN 1.1. KHI NIM CHUNG 1.1.1. Khi nim chung San nn l mt hng mc chim t trng vn u t kh ln trong hu ht

cc loi cng trnh, c bit l cc khu vc ven sng, bin khi cn to mt bng ln ra mp nc. Cng tc san nn ven bin thng i hi mt khi lng vt liu (t, ct, ) san lp ln v qu trnh thi cng lun chu tc dng thng xuyn ca qu trnh bin i do t nn c kt, triu, sng bin...

San nn ven bin c th phc v nhiu mc tiu khc nhau nn vt liu san nn, m cht nn t ph thuc vo yu cu ca bi ton thit k.

1.1.2. c im thi cng san nn ven bin - Thng dng vt liu t ct khai thc ti ch tr mt s trng hp c

yu cu thit k c bit, do thng gim cc ph vn chuyn. Tr lng ni chung thng p ng c yu cu nn khng b nh hng v tin hay cng thi cng.

- Vt liu d khai thc v bo qun. - Ty loi vt liu san lp m c nhiu bin php khai thc, vn chuyn,

san lp - m cht khc nhau - Khi lng san lp thng ln, cng tc t chc thi cng khng phc tp.

C th p dng thi cng c gii trn quy m ln. - Khi i hi m cht cao trong thi gian thi cng ngn th thng phi

yu cu v m t nhin ca t hp l cng tc m nn hiu qu nht. 1.1.3. Cc yu cu chnh a) M vt liu, bi tp kt vt liu: - M vt liu phi p ng cc yu cu theo tiu chun thit k. - C phn nh vng khai thc, tp kt vt liu. - C quy trnh khai thc, tp kt vt liu. - C h thng thot nc cho m vt liu cng nh bi cha vt liu. - C ng cng v khai thc v vn chuyn. - C phng n hon th li lp t hu c sau khi khai thc xong (vi

t trng trt). b) Cng tc san lp - T chc cng tc khai thc, vn chuyn vt liu hp l.


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- C quy trnh san lp, m cht hp l. - C h thng thot nc quanh khu thi cng. - X l lng ngm nc (nu c). - C bin php tu sa, bt mi, bo v mi t c bit l pha mt nc. - C quy trnh kim tra cht lng, khi lng t p. c) T chc thi cng c gii Thi cng san lp t thng l s dng cc loi xe my chuyn dng

tng nng sut, y nhanh tin thi cng. Do vy m bo hiu qu kinh t v cht lng thi cng cng trnh, thi cng c gii cn m bo nhng nguyn tc c bn sau:

- Tn dng ht nng sut ca my, m bo s phi hp nhp nhng gia cc cng on v hn ch n mc ti a s ca trng ca my.

- Chn t chng loi my, khai thc ht mi tnh nng ca my. - La chn thit b thi cng phi ph hp vi iu kin khu vc thi cng,

bin php thi cng. - Tn dng c cc xe my, thit b sn c. 1.2. VT LIU SAN LP 1.2.1. Nguyn tc la chn - Vt liu m khai thc phi m bo mi tiu chun yu cu ca thit k.

Nu vt liu san lp l t dnh th phi c m ph hp. - Nn chn m khai thc vt liu gn khu vc san lp gim qung

ng vn chuyn. Vt liu c cu to ng u, d khai thc, vn chuyn bng cc phng tin c gii. C h thng giao thng tip cn thun li.

- Lp vt liu khai thc phn b trn b mt, a hnh phng, mc nc ngm thp (nu khai thc m t ct trn cn).

- t nh hng tiu cc n mi trng xung quanh nht. 1.2.2. Nguyn tc tn dng - Li dng khi t o vo khi t p, khu vc o no th p vo khu

vc lp . - Hn ch vt liu vn chuyn t ni xa n. - C kh nng p dng cc phng tin thit b c cng sut ln khai

thc, vn chuyn, san lp... 1.2.3. Nguyn tc chn phng n khai thc vt liu


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Khi thi cng san lp mt bng thng phi tin hnh cng tc o khai thc vt liu nh t, ct, ... Ni chung khu khai thc vt liu thng l khu u tin trong dy chuyn sn xut ca thi cng san nn v chim khi lng rt ln. V th gii quyt c khu ny s c c 1 ngha thc tin ln.

Cn c vo vic s dng my mc trang thit b c th chia lm 4 phng php o t c bn: o t bng th cng, my o, n mn, thy lc.

Yu cu c bn ca cng tc khai thc vt liu: - ng n thit k; - Nng sut cao - m bo an ton cho my mc thit b v con ngi Nguyn tc thc thi: - Chn dng c, my mc thi cng thch hp vi loi vt liu khai thc,

iu kin hin trng v khi lng khai thc; - T chc thi cng khoa hc; - To iu kin thi cng d dng; - D dng phi kt hp vi cc phng tin bc xp v vn chuyn. 1.3. THI CNG SAN NN 1.3.1. Thit b khai thc vt liu a) My o mt gu + Cu to, tnh nng my o gu nga :

Hnh 3.1a: My o gu nga Hnh 3.1b: My o gu sp


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B phn cng tc ca my o gu nga bao gm: Gu, tay gu, cn chng, mt s rng rc v dy cp. u di ca cn chng c ni tip bng khp vi b quay ca my. u trn dng h thng dy cp v rng rc thay i gc nghing v gi n nh gc nghing . gia cn chng c b phn c bit lin kt vi tay gu. u tay gu c lp gu, tay gu c th dch chyen ra vo c. Mt trc gu c 3 5 rang c th tho lp c y gu c np ng m. Nh h thng ng m lm cho np gu ng li khi o v m ra khi .

- Khi o t gu vn ng cng bc t di ln v nh lc y, lc p tay gu c a v pha trc tin hnh o t.

- My o gu thun thch hp khi o cao hn mt bng my ng v nng sut o cao.

+ Cu to, tnh nng my o gu sp: B phn cng tc ca n bao gm : cn chng, tay gu mt s rng rc dy

cp t hp. Cn chng c ni vi khp bn l b quay v di ng trn mt phng thng ng khi lm vic. Tay gu ni vi u mt cn chng c th quay quanh khp . Khi thao tc dng dy cp ko gu. Cui tay gu c dy cp ni vi thanh chng ng thao tc. Tc dng thanh chng ng l nng cn chng ng gim bt lc dy cp khi ko cn.

Phm vi ng dng: ng dng o nhng khi o thp hn mt bng my ng.

+ Cu to, tnh nng my o gu dy: B phn cng tc c cn chng tng i di, gu, dy cp ko gu v dy

cp nng gu. u di cn chng c ni bng khp ni vi b quay. u trn gi bi rng rc v dy cp. Khi bt u o th bung lng dy cp nng gu ng thi vng mnh v pha trc cho gu h xung. Dng dy cp ko gu v pha thn my. Khi y gu thi dng dy cp nng gu ko ln trong qu trnh o trt t gc nghing cn khng thay i.

1) Thn my; 2-4) puly; 3) cn vi; 5-7-8) cp ko; 6) gu o Hnh 3.2: My o gu dy


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Phm vi ng dng : Khai thc vt liu, no vt di nc. Thch hp vi phng n o t khng phi hp vi phng tin vn chuyn.

+ Cu to, tnh nng my o gu ngom: Nu thay gu xc my o gu dy bng gu xc kiu ngom th n tr

thnh my o gu ngom. Gu ngom c 2 - 4 mnh hm hp thnh. Gu c treo bi dy cp nng gu. Dy cp ngom dng thao tc cc

mnh hm khi ngom t. Khi ngom t cc mnh hm gu c m ra v gu h xung. Di tc dng ca trong lng bn thn gu cm su vo t. Ko cng cp ngom 2 mnh c ng li. Khi ti v tr t th ni lng cp ngom di sc nng ca trng lng bn thn 2 mnh gu m ra t c ra ngoi.

Phm vi ng dng: Do ch da vo trng lng bn thn o v xc t do my o gu ngom thch hp khi o t ri, t nh, o h mng ging su v hp.

Hnh 3.3: My o gu ngom

b) My o nhiu gu My o nhiu gu l loi my o lin tc nh c cc gu o gn vo

vng xch hoc rto. My thc hin o, vn chuyn, vt liu, di chuyn ng thi mt lc.

Vic s dng my xc nhiu gu ch c hiu qu kinh t cao hn my xc 1 gu nhng cng vic cn nh hnh ho v chuyn mn ho cao vi khi lng cng vic ln v v tr o tp trung.

Thng my xc nhiu gu c phn loi theo thit b mang gu: - My xc nhiu gu loi bng hay xch mang gu


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- My xc nhiu gu loi rto mang gu. Cn c vo hng di chuyn ca my gm 2 loi: My o kiu bn cnh

v my o kiu hng dc: - My o kiu bn cnh l loi my o khi o my dch chuyn cnh

khi o (hng di chuyn ca gu vung gc hng di chuyn ca my). Thng s dng o knh mng ln vng bng phng, no vt lng sng hay khai thc vt liu ct si c th o theo kiu hnh qut hay song song.

- My o kiu hng dc : l loi my khi o t th dch chuyn theo tuyn khi o, phng di chuyn ca my trng vi phng di chuyn ca gu, cu to ging my o kiu bn cnh thng dng o mng rnh hp.

+ My o nhiu gu loi xch mang gu My gm cc gu gn vi bng xch cch u nhau. Xch mang gu mt

u c quay c nh ng c qua h truyn ng, cn u kia c ko cng bi a. Gi gu c treo cn bng nh cn treo v i trng.

Khi my lm vic, xch mang gu di chuyn gu s ct vo vt liu, gu di chuyn qua a ri vng li nguyn liu cha trong gu vo phu cha hoc thit b vn chuyn. Phm vi s dng:

My xc nhiu gu loi bng hoc hoc xch mang gu c kh nng khai thc t cp 1 hoc cp 2. V tr khai thc trn, di hoc ngang mc t my.

1- xch; 2- gu o 3-4- puli 5- gi gu 6- cn treo 7, 9- i trng 8- phu 10- thit b vn chuyn 11- thit b di chuyn

Hnh 3.4: S my o nhiu gu loi xch mang gu

u im: Kh nng c gii ho ng b cao, nng sut ln. C kh nng hon thin

tng o, thi cng theo tuyn, iu khn d dng v nh nhng hn. Nhc im:


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- Vic s dng my xc nhiu gu ch c hiu qu kinh t cao hn my xc 1 gu nhng cng vic cn nh hnh ho v chuyn mn ho caovi khi lng cng vic ln v tp trung.

- My o nhiu gu khng a nng. Gi thnh ch to, mua sm v chi ph duy tu bo dng ln...

+ My o nhiu gu loi roto mang gu My gm rto c lp vo tay my. Trn rto lp u cc gu xc c

rng. Trong tay my c t thit b vn chuyn (bng ti ). Rto, tay my v thit b vn chuyn c gi v tr cn bng xc nh nh cc cn treo.

Khi my lm vic rto quay, cc gu gn trn rto o vo tng vt liu v vo thit b vn chuyn.

My xc nhiu gu loi rto mang gu thng dng khai thc t loi 1 n loi 3.

My thng c t cao trnh thp hn mt phng o. 1- rto 2- tay my 3- gu 4,5- bng ti 6- xe ch VL 7,8- cn treo 9- bung my 10- thit b di chuyn

Hnh 3.5: S nguyn l hot ng my o t loi Roto mang gu

Hnh 3.6: My o 288 do cng ty Krupp ca c sn xut nm 1978

(th tch 6,6 m3/gu, c tc quay 48 vng/pht)


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u im: - Lc ct vo nguyn liu ln hn nn khai thc c nguyn liu rn hn. - Nng sut khai thc cao.

Nhc im: tng t nh my o nhiu gu loi xch mang gu c) Tu cuc: Tu cuc l mt thit b o t kiu nhiu gu lp trn tu hay x lan

o cc bi bi lng sng, khai thc ct, si di nc. - Cu to bao gm cc b phn ch yu nh hnh v: gi gu, dy xch,

phu vt liu, bng chuyn. Tu cuc khng th t di ng m nh lc ko dy neo. Vt liu o c thng qua bng chuyn chuyn n cng c vn chuyn.

- Qu trnh cng tc ca tu cuc gm cc ng tc o t, vn chuyn t v di chuyn c tin hnh cng 1 lc.

- Nng sut tu cuc f (tc chuyn ng ca gung xch, tnh cht ca t, dung tch gu, dy lp o)

B tr o t cho tu cuc gm 3 phng php: -Phng php 1: mt pha ng vn chuyn chnh b tr nhiu ng nhnh song song

nhau. C ly gia cc ng nhnh cn c chiu di bng chuyn xc nh. u tin o mt bn ng nhnh vt liu o c qua bng chuyn

xung cc cng c vn chuyn dng trn ng nhnh. Qu trnh o ln lt tho d di chuyn cc ng nhnh cui cng cn li nn ng.

u im: - Ph hp vi din cng tc hp c th phi hp vi nhn cng v cc my

o khc. - Thit b trn ng nhnh c nh, ph tn vn chuyn t. Nhc im: - Khi lng o t, th tch nn ng lu li ln - Phng php 2: B tr khong cch cc ng nhnh tng gp 2 so vi phng php 1,

khong gia 2 ng nhnh tin hnh o 2 ln, ln lt t sang 2 bn khng o mt nn ca ng nhnh.

u im: - Din cng tc rng c th phi hp vi nhn cng v my o khc. - Thit b trn ng nhnh c nh, ph tn vn chuyn t.


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Nhc im: - Khi lng o t, th tch nn ng lu li ln - Phng php 3: Khong cch 2 ng nhnh nh phng php1. Khi o dng 2 tu, tu 1

o c 1 khong nht nh th tu 2 bt u o, tu i sau s o ng nhnh m tu 1 o.

u im: - C th o c khi lng ln, nn ng lu li t. Nhc im: - Khi 1 tu h hng cn tr lm vic lm tu san phi dng

Hnh 3.7: Tu quc

u nhc im ca tu cuc: Tu cuc c kh nng no vt bn ct vi khi lng v cng sut ln, c

kh nng no vt t c bn cao (t cp 2). su no vt ln. Tnh a nng khng cao, chi ph ch to, duy tu sa cha ln...

Hnh 3.8: Bng truyn vn chuyn vt liu trn tu quc


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d) Tu ht

Tu ht thng c s dng ph bin trong cng tc o bn, ct. Vi kh nng c ng, cng sut ln v vn chuyn vt liu qua ng ng nn c th vt qua cc a hnh phc tp nh sng, m...

Cu to gm tu, my bm ht bn ct. ph v kt cu bn ct, tng hiu qu ht mt s loi b tr thit b ct t u bm. Bn ct c ht cng nc ln bng tu hoc chuyn qua ng ng n bi tp kt. Bn ct s ng li v nc thot i.

Hnh 3.9: M hnh tu ht ct

u nhc im ca tu cuc: Tu ht c kh nng no vt bn ct vi khi lng v cng sut ln, c

kh nng no vt t c bn cao (t cp 2). su no vt ln. Tnh a nng khng cao, chi ph ch to, duy tu sa cha ln...

Hnh 3.10: Khai thc bng tu ht phun


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e) Khoan n Phng php khoan n mn cho php ph v cc cu trc cng m cc

thit b khc khng ph c. Phng php ny thng dng trong khai thc hoc o .

u im: - C th p dng khai thc hoc o vi bt k loi t no. - Khi lng thi cng a dng t nh n ln. Nhc im: - Ga thnh thng cao vi t mm (t cp 1, cp 2). - Mc i hi tnh chuyn nghip cao, cng tc an ton phc tp. 1.3.2. Chn phng n vn chuyn vt liu Chn phng n thi cng da trn cc c s sau c phng n ph hp

nht v chng loi thit b, cng sut thit b: - Tnh cht ca m vt liu: trn cn hay di nc; t dnh hay t ri,

b dy lp t khai thc ... - Khi lng san lp; - Khong cch vn chuyn, cc cung ng vn chuyn; - My mc hin c... - iu kin a hnh hin trng thi cng; - Kh nng tip cn ca cc phng tin vn chuyn; - S phn b cc bi ly t, khi lng, cng vn chuyn v thi k

thi cng; - Hnh dng, kch thc khi o, p, s quan h vi cng c o p; - Yu cu v cht lng o ph; - Tnh hnh cung ng nhn, vt lc vn chuyn. a) Vn chuyn bng t - my ko u im: - Yu cu v ng s khng cao, dc ng cho php ln, bn knh

cong ca ng nh. - K thut lm ng n gin, cng tc lm ng nhanh chng. - Phm vi ng dng tng i ln thch hp vi a hnh phc tp, din

cng tc hp, c tnh c ng ln. - p ng c cho mi loi vt liu, khong cch; Nhc im:


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- Ph tn vn chuyn ln, ng s thng xuyn phi tu sa; - Khi dng phi hp vi my xc, h s phi hp xe my thp hn khi my

xc phi hp vi ng ray. Mt ng rng hay hp ty thuc cp ca ng b, s ln xe chy, tc xe chy, thit k thng 3 - 6m

- Dc 2 bn ng phi c rnh thot nc trnh tnh trng ng b ly li khi ma xe khng chy c.

- Ga thnh thng cao; - Tc thi cng thng chm.

Hnh 3.11: Khai thc vt liu bng my o, vn chuyn bng xe vn ti

b) Vn chuyn bng tu thy u im: - Kh nng vn chuyn vi khi lng ln; - Tin nhanh, c th p ng tt vi cc tuyn vn ti xa; - t nh hng n h tng giao thng; - Phng tin vn chuyn a dng t n gin n phc tp; - Ga thnh vn chuyn thng thp hn vn chuyn bng ng b. Nhc im: - Thng khng ph hp vi khi lng san lp nh; - i hi phi c lung lch, bn cp... - Thng phi kt hp vi bin php bc xp, chung chuyn bng cc

phng tin khc nh t, my xc... - Thi gian hot ng ph thuc nhiu vo iu kin kh tng hi vn.


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Hnh 3.12: Vn chuyn bng phng tin ni

c) Vn chuyn bng ng ng Vn chuyn bng ng ng thng p dng cho cng tc san lp bng vt

liu ct vng c kh nng cp thot nc thun li. u im: - Tc thi cng san lp nhanh, khi lng thi cng ln; - C th vn chuyn qua c cc vng a hnh phc tp nh vt sng,

m ly... - Ga thnh thng thp; - Hot ng c trong nhiu iu kin thi tit phc tp. Nhc im: - Khng ph hp vi khi lng san lp nh; - Khng ph hp khi khong cch m vt liu n khu san lp xa; - Ch ph hp vi vt liu ht nh nh bn, ct.

Hnh 3.13: Khai thc, vn chuyn bn ct bng tu ht - ng ng


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1.3.3. Chun b thi cng - Khi b tr mt bng thi cng khng lm nh hng n s hot ng v

cnh quan chung, m bo giao thng, an ton v sinh mi trng. - B tr mt bng thi cng phi hp l thun tin, hn ch ti a bi, ting

n lm nh hng n hot ng ca khu vc xung quanh v khng gy cn tr n qu trnh thi cng san lp.

- B tr phng tin thit b thi cng hp l. - m bo an ton trong qu trnh thi cng . - m bo an ninh trt t v phng chng chy n tt. 1.3.4. Thi cng san lp Ch bt u tin hnh san mt bng cng trnh khi c thit k san nn,

cn i khi lng o p v c thit k ca tt c nhng cng trnh ngm trong khu vc.

Cng tc san lp gm cc cng on chnh sau: - vt liu, san gt vt liu, m nn trn mt bng. - X l thot nc, khng nc chy trn qua mt bng v khng

hnh thnh vng ng trong qu trnh thi cng. - Bt mi, thi cng lp bo v mi. - Kim tra cht lng t m cht. i vi tng phn vic, cn t chc b tr cng vic sao cho hp l tng

nng xut y nhanh tin v m bo yu cu cht lng m gi thnh r. a) Bin php p t nn p nn bng vt liu t thng c p thnh cc lp ngang dy khng

qu 30cm (trng hp p t bng ct th c th dy hn). m ca t m phi ph hp t hiu qu cao trong lu nn.

B dy mi lp t ri m v s ln m cho mi lp ph thuc vo loi my m s dng h s m v loi t p. Nn ri t c dc 0,005 theo chiu thot nc.

Khi p t khng m nn phi tnh ti chiu cao phng ln. T l chiu cao phng ln tnh theo % phi theo ng ch dn trong bng 3.1.

b) m cht Cng tc m cht ph thuc vo yu cu thit k. C th s dng cc thit

b lu, m, p gia ti... lm cht t p. - m cht:


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cht yu cu ca t c biu th bng khi lng th tch kh ca t hay h s lm cht. cht yu cu ca t c quy nh trong thit k cng trnh trn c s kt qu nghin cu t theo phng php m nn tiu chun, xc nh cht ln nht v m ln nht ca t.

Chnh v l , th nghim m cht trong phng (22TCN 333:06) nhm mc ch tm gi tr ti hn ca khi lng th tch kh gkmax v m ti u W0 ca t dng lm san nn ng vi mt cng m nn theo tiu chun nht nh v dng lm cc thng s i chiu vi kt qu th nghim cht hin trng kt lun cng m nn ngoi hin trng t bao nhiu phn trm so vi cng m nn trong phng ( cht K%).

Mun t dc khi lng th tch kh ln nht, t p phi c m tt nht. sai lch v m ca t p i vi t dnh 10%; i vi t khng dnh 20% ca m tt nht.

Trc khi p phi bo m t nn cng c m trong phm vi khng ch. Nu nn t qu kh phi ti thm nc. Trong trng hp nn b qu c th phi s l mt nn c th m cht. Phi nh xm mt nn ri mi lp t p tip theo. Phng php s l mt nn cn xc nh tu theo loi t c th trn thc a.

Phi m bo lp t c v lp t mi lin kt chc vi nhau, khngc hin tng mt nhn gia hai lp t, m bo s lin tc v ng nht ca khi t p.

i vi cc cng trnh dng, gi v dn nc, trc khi lp t mi bt buc phi o, cuc xm lp t c. Nu s dng m chn d th phi nh xm tr hng ch ngi v xe i nhn.

Khi t dnh khng m tt nht th nn ti thm ni ly t ( m t, bi vt liu, khoang o, ch t d tr). i vi t khng dnh v dnh t khng m tt nht th c th ti nc theo tng lp ch p t.

Lng nc cn thit (tnh bng tn) tng thm m ca 1m khi t trong khoang o, bi vt liu c xc nh theo cng thc :

g = Vt (Wy - Wb + Wn) Trong : Vt- Khi lng th tch kh ca t ti m (T/m3) Wy - m tt nht ca t (%) Wb - m ca t ti bi vt liu (%) Wn - Tn tht m khi khai thc, vn chuyn v p t (%)


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Lng nc yu cu (g) tnh bng tn ti thm cho 1m2 lp t khng dnh hoc t dnh ln khi t p, Tnh theo cng thc:

g = Vkh (Wy - Wt) Trong : Vk - Khi lng th tch kh ca t m (T/m3) h - Chiu cao lp t (m) Wy - m tt nht ca t (%) Wt - m thin nhin ca t ln mt khi t p (%) Lp t c ti nc thm trn mt t khi p ch c m sau khi

c m ng u trn sut chiu di ca lp t ri. Tuyt i khng c m ngay sau khi ti nc. i vi t khng dnh nh ct, si, mc d khi ti nc ngm nhanh, cng phi ch cho nc ngm u ton b b mt v chiu dy lp t ri mi c tin hnh m nn.

Vic m nn khi t p phi tin hnh theo dy chuyn tng lp vi trnh t , san v m sao cho thi cng c hiu sut cao nht, chiu dy ca lp m phi c quy nh tu thuc v iu kin thi cng loi t, loi my m s dng v cht yu cu. Khi ri t m th cng phi san u, bo m chiu dy quy nh cho trng hp p t bng th cng. Nhng hn t to phi bm nh, nhng mng snh, gch v, hn to ln trong t phi nht loi b. Khng c t d tr trn khu vc ang m .

Cn phi xc nh chiu dy lp ri v s lt m kt qu m th nghim.

m t dnh, phi s dng dm bnh hi, m chn d, my m nm. dm t khng dnh phi s dng cc my m rung, m nm chn ng v m bnh hi.

Trc khi m chnh thc, i vi tng loi dt, cn t chc m th nghim xc nh cc thng s v phng php m hp l nht (p sut m, tc chy my, chiu dy lp t vi, s ln m, m tt nht, v m khng ch).

S dm c gii c 2 cch: m tin li v m theo ng vng. Nu m theo ng vng th phi gim tc di chuyn ca m on ng vng v khng c m st.

ng i ca my m phi theo hng dc trc ca cng rtnh p v t ngoi mp vo tim ca cng trnh. Khong cch t vt m cui cng ca my m n mp cng trnh khng c nh hn 0.5m.


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Khi m mi dc phi tin hnh t di ln trn, khng m mi t p trn mt ct ngang ca khi t p ln hn kch thc thit k, lp t tha phi bt i v s dng p cc lp trn.

Khi m, cc vt m ca 2 sn m k nhau phi chng ln nhau. - Nu theo hng song song vi tim cng tnh p th chiu rng vt m

phi chng ln nhau t 25 n 50 cm. - Nu theo hng thng gc vi tim cng tnh p th chiu rng phi

t 50 n 100 cm. Trong mt sn m, vt m sau phi ln vt m trc l 0.2m, nu

m bng my; v phi ln 1/3 vt m trc (m theo kiu xa tin) nu m bng th cng.

i vi cng trnh thu li th khng cho php m theo hng thng gc vi tim cng trnh.

Trong chn khi t p khng cho php c hin tng bung nhng. Nu c hin tng bng nhng vi din tch nh hn 5m2 chiu dy khng qu 1 lp m tu theo v tr i vi cng trnh c th cn nhc quyt nh khng cn x l v phi c s tho thun ca gim st thit k.

Trong trng hp ngc li nu ch bung nhng rng hp 5m2 hoc 2 ch bng nhung chng ln nhau th phi o ht ch bng nhng ny (o cc lp) v p li vi cht lng nh trong thit k yu cu.

Khi m t ca cc cng trnh (tr cng trnh thu li) bng my m chn d th phn t ti ca lp trn cng phi c m bng my m loi khc v nh hn.

Vic m t trong iu kin kh khn, cht hp (lp t vo cc khe mng, xung quanh cc gi ta ca ng dn, cc ging khoan trc, p t mt nn, ch tip gip t vi cng trnh...) cn phi tin hnh m bng cc phng tin c gi nh my m nm, m nm chn ng treo vo cc my khc nh cn cu, my ko, my o... nhng ch c bit kh m, phi s dng my m loi nh. Nu khng th m dc bngmy th phi m th cng theo cc quy nh hin hnh.

Sau khi so snh cc ch tiu kinh t k thut ca phng n p t bng c gii th cho php m rng cc ni cht hp ti kch thc m bo cho cc my m c nng sut cao lm vic.

Khi p tr li vo h mng c kt hp tn dng t o p nhng nu loi t tn dng khng m bo c cht lng th phi s dng t khc. Phi s dng loi t t b bin dng khi chu nn nh ct, ct si.


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Khi la chn cc gii php kt cu phn di mt t , c qua thit k phi to mi iu kin c th c gii ho ng b cng tc t, m bo cht lng m nn v s dng my mc c nng sut cao.

Trong qu trnh p t, phi kim tra cht lng m nn mu kim tra ti hin trng cn tnh theo din tch (m2). Khi kim tra li t p th tnh theo khi lng (m3). V tr ly mu phi phn b u trn bnh , lp trn v lp di phi xen k nhau (theo TIU CHUN Vit nam TCVn 4447-1987 bnh khi p)

Khi lng th tch kh ch c php sai lch thp hn 0.03T/ m3 so vi yu cu ca thit k. S mu khng t yu cu so vi tng s mu ly th ngim khng c ln hn tp trung vo mt vng.

Mi lp m xong phi kim tra Vk. Ch c p tip lp sau nu lp trc p t yu cu v cht thit k.

Trong qu trnh thi cng san lp cn ch n bin php quan trc ln, mc cao ...

i vi trng hp san mt bng sai lch so vi cao trnh thit k (o cha ti hoc o vt qu cao trnh thit k) phn o t cho php nh sau:

- i vi t mm: 0,05 khi thi cng th cng v 0,1m khi thi cng c gii. - i vi t cng: +0,1m v -0,2m. Nhng ch o vt qu cao trnh

thit k phi c lp phng bng hn hp. Bng 3.1: d phng ln t p khng m cht (%)

Mt s loi thit b m t: - m ln p: S dng thit b c trng lng ln ln p cht t. Lc

tc dng thng coi nh tnh, tr s p lc nn n nh theo vng ln v thi gian.


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1-Khung m 2- Trng m 3- Li no 4- Trc m 5- Vt iu chnh

Hnh 3.14: Cu to m ln phng - m xung kch: S dng tc ng xung kch to lc p t, lc m

nn l lc ng v thay i theo thi gian ti mt a im. Nng sut thp so vi nhng loi m khc

c) Bo v mi dc Cng tc bo v mi dc c bit mi dc pha bin cn c ch c

bit. Mi dc phi m bo gi c vt liu trnh b xi tri nh hng n khu vc. Trng hp cn thit phi thit k h thng bo v mi tm thi nh bao ti ct, r ...


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CHNG 2. THI CNG NO VT LUNG LCH 2.1. KHI NIM CHUNG No vt v o p di nc l mt khu rt quan trng trong thit k v

thi cng cc khu nc neo u tu thuyn cng nh lung lch cho tu. Thm ch cng tc no vt cn l yu t quan trng u tin trong vic xc nh xy dng lung, cng.

Cng tc no vt duy tr lung lch, khu nc u tu... thng c thc hin theo nh k duy tr kh nng s dng cng trnh.

cng tc no vt lung lch t hiu qu th vn quan trng cn xc nh l:

- Khi lng no vt; - Tnh cht ca vt liu no vt; - c im a hnh khu vc no vt; - V tr tp kt vt liu no vt. 2.1.1. Khi lng no vt Vic xc nh chnh xc khi lng no vt rt quan trng trong vic chn

phng n no vt, nng sut no vt, thi gian thi cng v c th ti u gi thnh. Khi lng no vt c th t vi trm n hng chc, hng trm triu mt khi. xc nh chnh xc khi lng cn phi:

- C s liu chi tit mt bng khu vc no vt, su no vt yu cu v cc mt ct ngang thit k;

- S liu kho st a cht khu vc no vt; - Li khng ch cc im no vt trn mt bng. 2.1.2. c im vt liu Xc nh c tnh ha l ca vt liu no vt lm c s cho vic la

chn phng php thi cng, kh nng s dng sn phm no vt, x l cht thi v nh gi tc ng mi trng.

Tnh cht vt l: Tnh cht c l ca vt liu quyt nh vic la chn my mc, thit b v

phng thc no vt do nh hng n chi ph thi cng c bit khi phi di chuyn cc thit b t xa n. Vic phn loi vt liu c th theo cc loi trm tch bn ct, ct, st...

Tnh cht ha hc: Cc thnh phn cht ha hc c hi trong vt liu no vt c th c nh

hng ln n mi trng khu vc xy dng. V vy cn c thng tin v cc


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thnh phn ha hc c hi trong vt liu no vt c bin php x l ph hp trnh gy tc hi n mi trng. ng thi phi xc nh vng nh hng (khu vc no vt, ng vn chuyn, khu vc vt liu...).

c im sinh vt: Vn sinh vt trong khu vc no vt cng phi xem xt iu tra mt cch

k lng. Trng hp cn thit phi c bin php thi cng ph hp tng ng gim thiu tc hi n sinh vt khu xy dng.

2.2. BIN PHP NO VT Sn phm no vt lung lch, khu nc thng l mt trong cc loi trm

tch: - Vt liu ri nh ct, ct pha; - Vt liu dnh kt nh st, st pha; - Bn, bn st do ph sa, sa bi... - Cc loi nh san h, vi... Ty thuc vo c im ca vt liu no vt, khi lng no vt... c th

la chn mt hoc kt hp nhiu bin php, phng tin. 2.2.1. Tu gu ngom Tu gu ngom l loi c dng kh ph bin. C th s dng cho cng

tc no vt, bc xp nhiu loi vt liu. Khi no vt bn t tu gu ngom thng c neo bng h thng 01 neo

ch cng cc neo bin v tin hnh o t theo phng ngang. Bn t c vo bng tu v ch n v tr tp kt (i vi tu t hnh) hoc ln tu khc ch n v tr tp kt (i vi khng t hnh).

Hnh 3.10 : Tu gu ngom

u im: - Linh hot, ph hp vi nhiu loi vt liu no vt nh bn, ct, si...


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- C th lm vic trong iu kin mc nc t nng n su, c th t n su nc ln (c th ti 35m hoc hn, ph thuc vo trng lng gu);

- Thun tin cho thi cng trong cc khu vc bn, cc gc c a hnh hp, khi lng no vt nh, chiu dy lp no vt mng.

Nhc im: - Cng sut no vt khng ln; - a hnh y h o khng ng u, kh to cc mi taluy; - Khng ph hp vi loi vt liu c tnh lin kt ln nh st cng, khi

Hnh 3.11 : Tu o gu ngom


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Hnh 3.12 : gu ngom 2.2.2. Tu o gu thun Tu o gu thun l loi thit b c dng kh ph bin v a nng. n

gin nht l loi my o gu thun t trn ponton ngoi ra cn c loi tu o t hnh. C th s dng cho cng tc no vt, bc xp nhiu loi vt liu.

Tu o t hnh loi ln c th hot ng trong iu kin sng gi kh ln, th tch gu o c th n 40m3. Tu o thng vt liu ln phng tin khc ch i, t l gia vt liu rn v nc trong sn phm o thng ln. Tu gu o thng tin hnh o theo phng ngang v nh v bng h thng chn chng.

Hnh 3.13 : My o gu thun trn poton

u im: - Linh hot, ph hp vi nhiu loi vt liu no vt nh bn, ct, si, san

h... - C th lm vic trong iu kin mc nc t nng n kh su, c th t

n su nc ti 32m (ph thuc vo tay vi ca gu);


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- Thun tin cho thi cng trong cc khu vc bn, cc gc c a hnh hp, khi lng no vt nh, chiu dy no vt mng.

Nhc im: - Cng sut no vt thng khng ln; - Khng c kh nng thi cng su nc ln.

Hnh 3.14 : Tu o t hnh

2.2.3. My o gu ko My o gu ko thng l loi thit b c cng sut nh. Cu to thng

l dng my o gu ko t trn ponton hoc trn xe xch. C th s dng cho cng tc no vt nhiu loi vt liu.

Hnh 3.15 : My o gu ko

u im: - Linh hot, ph hp vi nhiu loi vt liu no vt nh bn, ct, si...


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- C th lm vic trong iu kin mc nc t nng n su, c th t n su nc ln (c th ti 35m, ph thuc vo trng lng gu);

- Thun tin cho thi cng trong trong trng hp khi lng no vt nh, chiu dy no vt mng.

Nhc im: - Cng sut no vt khng ln; - Khng ph hp vi loi vt liu c tnh lin kt ln nh st cng,

khi... - Khng thun tin cho thi cng trong cc khu vc bn, cc gc c a hnh

hp. 2.2.4. My bm trn phao ni My bm c gn trn gi (cn iu khin) kt ni trn phng tin ni.

Thit b ny thng s dng cho vic no vt bn, ct ht nh.

Hnh 3.16 : My bm trn phao ni

u im: - C kh nng no vt bn ct ht nh vi cng sut khng ln; - Vn chuyn sn phm no vt bng ng ng nn c th vt a hnh

phc tp; - C th lm vic trong iu kin mc nc t nng n su, c th t n

su nc ln. - Thun tin cho thi cng trong trong trng hp khi lng no vt nh,

chiu dy no vt mng. Nhc im: - Khng ph hp vi cc loi vt liu c kch thc ht ln; - Khng ph hp vi loi vt liu t dnh nh st, st... - iu kin thi cng hn ch khi tc ng ca sng, dng chy mnh - a hnh y sau o khng ng u.


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Hnh 3.17 : My bm trn phao ni 2.2.5. Tu ht bn-ct

y l dng thit b t hnh s dng bm ht. C th dng ngay bng tu cha vt liu sau vn chuyn n v tr hoc vn chuyn bng ng ng bm. Thng s dng trong trng hp khi lng no vt ln.

Hnh 3.18: Tu ht bn-ct

u im: - C kh nng no vt bn ct ht nh n va vi cng sut ln; - Vn chuyn sn phm no vt bng nhiu cch nh cha trn tu, bm

ln tu khc hoc ng ng nn c th vt a hnh phc tp; - C th lm vic trong iu kin mc nc su (c th t n su

nc ln ti 120m), sng dng chy ln; - C th ch to thit b vi nhiu cng sut, kch thc p ng a dng

cng vic Nhc im:


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- Thng khng ph hp vi khi lng no vt nh; - Kh t su chnh xc; - Chi ph huy ng, di chuyn thit b kh ln. 2.2.6. Tu cuc Tu quc thuc dng my o nhiu gu. Thng thng cu to gu c th

t 50 n 1000 lt, kh nng no vt thng thng n 25m thm ch c th t n 34m.

u im: - Kh nng no vt nhiu loi bn t; - Cng sut a dng theo cp ; - C kh nng di chuyn linh hot, no vt cha ng vn chuyn. Nhc im: - Chi ph huy ng, di chuyn thit b kh ln.


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CHNG 3: THI CNG BO V B BIN 3.1. KHI NIM CHUNG bo v b thng c thi cng ven bin trong iu kin mi trng

bin i lin tc v phc tp. V vy vic la chn thi im (ma) thi cng, thi gian thi cng l mt yu t v cng quan trng. Mt s khu vc cc cng trnh ch c th xy dng trong mt ma nht nh trong nm.

Cng trnh k thng thi cng trong iu kin chn khay v mt phn thn ngp nc nn i hi cc bin php thi cng thit b c bit.

Thi cng tng on theo hnh thc cun chiu: Thi cng t di chn ln nh , thi cng chn khay trc sau thi cng mi bin. Pha ng v ng mt , trng c thi cng sau.

3.2. Thi cng chn khay

Chn khay ca c th l cc: g, b tng, c thp, ng buy, hc... chn khay thng xuyn ngp di nc nn cn phi c bin php m bo thi cng nhanh trnh xt l mi h o. Thng phi xc nh thi gian triu rt v tranh th thi gian triu thp d dng thi cng.

- Chn khay bng cc g, b tng, c thp: th c th p dng thit b ng t trn b hoc di nc.

- Chn khay l ng buy b tng: c th o mng bng my o gu sp, cn di. Ch cho nc triu h xung, o n u, h ngay ng buy ri chn ct xung quanh hoc r . Bn trong ng buy c th hc, cn chnh v y np ng buy nu c. Cng c th h ng chn khay theo phng php h ging: h ng buy v dng bm p lc xi t nn h ng buy xung.

- Chn khay hc: c th o mng bng my o gu sp, cn di. Ch cho nc triu h xung, o n u, th ngay hc n .

Hnh 3.19 : Thi cng chn khay bng ng buy BT


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- Chn khay hc: c th o mng bng my o gu sp, cn di. Ch cho nc triu h xung, o n u, th ngay hc n .

3.3. Thi cng thn 3.3.1. Quy trnh k thut p Ln ga theo mt ct thit k S dng cc v dy ln ga trn hin trng theo mt ct thit k, cch

nhau khng qu 50m. Cc mc nh dng phi thng xuyn kim tra cn chnh m bo chnh xc v kch thc, v tr.

o c Khi lng p xc nh trn c s o c mt ct ngang trc v sau

khi p (ton b hoc tng phn). Cn o c, m bo chnh xc theo yu cu cc kch thc v v tr cng trnh theo thit k.

Chun b nn ( mi v nng cp) San bng cc l hng, ch trng v tin hnh m k theo tiu chun. Lm

m nn b mt nn c hoc mi ni tip vi lp t p mi. Nu mi c c nng cp th phi nh cp vi chiu cao ln nht mi cp bng 2 ln chiu dy lp m (khong 30 cm).

Vt liu t p Phi loi b tt c r cy, bi cy, c hay tt c cc loi vt liu d b phn

ra khc khi thn . p theo tng lp lin tc, trc ht p theo chiu ngang, sau p ln dn theo cao ca . Ni ly t phi cch chn t nht 20m (nm ngoi phm vi bo v )

Cng tc m nn: Ri t v san m cc lp trn mt thi cng m bo theo dy nht

nh, m cht n cht thit k. Trong qu trnh ri t cn phi ch m ca t c th t hiu qu m cht cao nht


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Hnh 3.20 : Thi cng thn

3.3.2. Cnhg tc m cht thn Ty vo loi vt liu p , quy m , mt bng thi cng m la chn

thit b m nn ph hp. - t pha ct hoc ct th s dng m hoc ti nc. - t st t th p dng theo phng php sau: + Xn, ct to thnh nhng khi t st c kch thc u nhau; + Vn chuyn khng lm ph v kt cu ca khi t st; + Xp nhng khi t st theo chiu ngang thnh tng lp u nhau, gim

ti a cc l hng gia cc khi t st; + Lp cc l hng bng t st v lm nhn mt tip xc; + Nn chia mi nhm thi cng mt khi lng thch hp (khong 10%

xp cc khi t st vo ng v tr). Khi m nn m ct bng bn rung th c th b tr mt hoc ghp hai, ba

m bn rung vi nhau, ri chia din m ra thnh nhiu khu vc nh m. m theo trnh t ng hng li t n cht trung bnh.

Trng hp m nn bng xe lu th yu cu vt lu phi st nhau. Sau khi m mt lt ngang xong th li phi chuyn sang mt lt dc khc v c tin hnh nh vy cho n khi t ti cht thit k.


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Hnh 3.21 : Thi cng m cht thn bng m v

Hnh 3.22 : Thi cng p bi thn Cc quy nh v kim tra cht lng Kim tra v mt ct Khi thi cng xong, c 100m phi kim tra kch thc hnh hc mt ct

theo tiu chun hin hnh. Kim tra cht lng m V ngm nc v dung trng kh cn ly mu th nghim khong

cch u nhau (1 mu/300m3 t p) vi cc thit b chuyn dng tin hnh phn tch ti cng trng v trong phng th nghim.


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Loi v s ln kim tra nh sau: - Dung trng v ngm nc ca t ti cng trng: Vi t ri nn th

nghim t nht 6 mu v ly kt qu trung bnh cho mi v tr. Vi t kt dnh, sau khi thc hin m nn nh nu iu 8.1.1.4, cn ly mu kim tra dung trng hin trng bng cch ly mu dao vng trn ming t st mu hnh khi, b mt nhn (kch thc thch hp cnh vung l 30 cm hoc 40 cm).

- Phn tch cp phi ht: Ly mt lng mu t thch hp phn tch cp phi ht.

- Tin hnh xc nh gii hn chy v gii hn do theo tiu chun hin hnh.

3.3.3. Thi cng lp m a) Bin php thi cng vi a k thut - Trc khi tri vi a k thut, mt bng mi phi c san hoc lp

t cao thit k v m n cht yu cu. B mt tip xc vi vi phi tng i phng, m bo cho vi tip xc tt vi nn. Nhng vt cng sc nhn phi c dn sch khng lm rch, hng vi.

- Nu c th th tho ht nc khu vc t vi lc hoc thc hin lc triu rt thp.

- vng khng c nc th o chn khay n cao trnh thit k v t vi lc, ghim cht vi chn khay v mi theo ch dn trong thit k.

- vng c nc, vi lc t vo rnh khay v ghim neo. Phi tri vi tip t chn ln mi trong iu kin c nc, ch ghim neo cn thn phn chn v mi ngp nc, trnh b y ni ra khi v tr tc dng do nc v sng.

- Ch tip gip gia hai tm vi cn chng m l 3050 cm. Nu may ni hai tm th cng ch ni phi t t nht 80% cng ca vi lc. Phn nh ca tm vi lc cn c nh chc chn, khng cho nc chy pha di v chng ph hy do ngoi tri thi gian di (khng qu 5 ngy), khng phi di nng nng.

Lu trong qa trnh thi cng, ngi thi cng phi chu trch nhim m bo vi khng b ph hoi khi t vi v khi m, trong nhng trng hp nhn thy cc im li trn vi, nh thu phi bo ngay cho cc k thit k c bin php gia c kp thi v cc lp tip theo.


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Hnh 3.23 : Thi cng lp vi m Kim tra cht lng thi cng vi lc Thc hin ngoi hin trng ng thi kim tra kch thc chn khay v

xp t k. Cht lng vi phi t yu cu thit v kim tra theo 14 TCN 91- 1996 n 14TCN 99- 1996: vi a k thut - yu cu k thut v phng php th.

b) Bin php thi cng lp m, lc ngc Chiu dy v cch t - Phi t ng v tr, cp phi v chiu dy nh trong bn v thit k. Cc

lp lc khng cn m, nhng phi thi cng m bo u nhau theo chiu dy quy nh.

- Cp phi lp m phi p ng theo yu cu thit k. - Thi cng cc lp m c thc hin t thp ln cao, v thng kt hp

thi cng lp ph ngoi ngay bo v trnh x, trt. Kim tra cht lng lp lc - Phi m bo chiu dy thit k, cho php chnh lch khng qu 10%. - Vt liu s dng lm lp lc p ng yu cu cht lng gii hn v

cp phi nh bng 9.2 v 9.3. - Theo chiu di , c 20m ly cc mu si ct dng lm lp lc phn

tch cp phi ht, kim tra dy.


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Hnh 3.24 : Thi cng lp m 3.3.4. Thi cng lp gia c mi

a) K xp, xy dng xy, lt phi cng rn, c chc, bn, khng b nt rn, khng

b phong ha, chng c tc ng ca khng kh v nc. Khi g bng ba, pht ra ting ku trong. Phi loi b pht ra ting ku c hoc c va canxi mm. dng xy, lt phi sch, t v tp cht dnh trn mt phi ra sch bng nc tng s dnh bm ca va vi mt . Nn chn loi c cng nn ti thiu bng 85 MPa v khi lng th tch ti thiu 2400 kg/m3. Ch tiu c l c th phi theo ch dn thit k

- Cht lng : Phi m bo cc tiu chun k thut ca tiu chun Cng trnh thy li- Xy lt - Yu cu k thut thi cng v nghim thu:14TCN 12-2002 v cc yu cu ca thit k.

- Xp t sao cho cc vin ln dc phn b ng u trn ton b din tch v nh hn c t xen k mt di, gia cc vin ln. B mt k khng c khe h ln. Khe h pha di cc vin c bt lp bng nh lm cho cc vin t st nhau, dy k ng u, khng ri dm trn b mt k.

- xp bng th cng, cc vin dng vung gc vi b mt ca mi dc. t vin theo chiu thng ng (nu chiu di ca hn bng chiu dy ca lp lt) v thng gc vi mt nn. i vi cc hn ln v qu di, c th t nghing (chiu rng ca hn bng chiu dy ca lp lt). Khng c xp hai vin dt chng ln nhau. Khe k gia cc vin lt ln c chn bng cc vin nh.


Trang35

- Cc vin lt khan hng trn cng ca mi nghing phi c cng hai mt phng: theo mi nghing v trn mt nn nm ngang.

- Lt trn mi nghing phi lt t di ln trn, chn cc vin ln nht lt hng di cng v hai bn ra ca phm vi lt . Khi lt phi m bo cht ch (cc vin tip xc cht vi nhau, vin trn t nht c 3 im tip xc vi cc vin di) nng cao tnh n nh ca mt lt mi dc.

- Sau khi lt , phi m bo mt nn cht ch v tng i bng phng. Chiu dy k phi m bo dy thit k. g gh ca mt lt mi dc khng qu 100mm so vi tuyn thit k.

- Trng hp vin c kch thc ln hn chiu dy ca k, th c th t chiu nh hn vung gc vi mi .

- gn va lin kt thnh khi ln: C th gn cc vin vi nhau bng va thch hp m bo yu cu v kch thc v trng lng theo thit k. Chn vt liu v phng php ghp bng va nh sau:

- t khun (g hoc thp) ln mi theo tun t t thp ln cao; - Mt c ti nc, t ln mi k sao cho khong cch gia cc vin

l nh nht, va s c pht vo cc khe h gia cc vin . - Xp thnh lp trn lp va lt ri chn cht cc khe k bng cc vin

hoc mnh nh ph hp, sau hn hp va vo khe k v chc bng bay hoc que m bng g to thnh mt khi lin kt cht v c chc. Ri dn lp va theo vic t cc vin lt c t trn hn hp va cn do, cha bt u ng cng.

- Cc lp lc bng ct si cn tin hnh ng thi vi vic t xp k. Kim tra cht lng k sau khi thi cng - Cht lng ca vin : Cn kim tra bng mt thng v cng nn

phng th nghim i vi c kch c khc nhau nu c s khc bit khi kim tra hin trng.

- B dy xp : Chiu dy k phi m bo khng sai lch vi thit k qu 5%.

- Cp phi k: Chn ly din tch 50 m2, tin hnh o ng knh ngoi ca mi vin , nh du bng sn hoc phn. Xp cc vin c cng kch thc vo trong mt nhm (theo bng 15), tnh ton xc nh t l % cho mi nhm.

Bng 9.1: Phn nhm


Trang36

STT Nhm STT Nhm 1 0,801,0 m 5 0,300,40 m 2 0,600,70 m 6 0,200,30 m 3 0,500,60 m 7 0,100,20 m 4 0,400,50 m 8 0,050,10 m

- T cc ng knh o c, xc nh din tch ca mi vin nhn vi chiu dy ca k v trng lng ring ca thuc mi nhm. Bng cch ny s xc nh c s phn b ca cc vin c kch thc trn b mt ca k . Cn m bo s c mt ca 50% s c trng lng trung bnh (w50), sai s cho php 10%.

- Cht lng k xy va: st m bo 39cm.C 30m3 va phi ly 6 mu va a v phng th nghim kim tra.

- Khi c ghp xong trn ton b cc khun mi tin hnh pht va xi mng, cn dng x beng ny va nht ht vo cc khe.Va pht l loi mc 1012,5 m bo tiu chun Va thy cng, yu cu k thut 14TCN 80-2001.

b) Cng trnh k b tng

- Ct, si, nc, xi mng dng ch to b tng k lt mi theo 14TCN66-2002 n 14TCN 73-2002 Vt liu lm thy cng - Yu cu k thut v phng php th.

- Thi cng cu kin BT c sn: Tm lt mi BT c thi cng c sn, dng h trong iu kin k thut khi cng mi vn chuyn lp ghp vo mi.

- Trc khi lp cu kin BT cn mim tra b mt sao cho sai s khng qu 5cm.


Trang37

Hnh 3.25 : Thi cng cun chiu mi k

Hnh 3.26 : Thi cng lp ph mi b tng

3.3.5. Thi cng mt , tng nh a) Thi cng tng nh - Chnh sa h mng b tng tng chn sng bng th cng. Dng my

thu bnh v ln ga h mng, m bo tun theo hng v kch thc theo h s thit k.

- m dm mng tng chn sng, m cht bng m cc.


Trang38

- Vn khun m bo kn kht trnh lm mt nc xi mng. Vn khun c vng chng bng cc g m bo chc chn, n nh v an ton cho thi cng b tng m bo ng v tr, kch thc c xc nh, nh du cao trn vn khun, vn khun c v sinh sch s bi du m trc khi lp t.

- Ct thp c gia cng theo ng n thit k v s hiu, hnh dng v yu cu k thut trong v c bo qun trnh ma v kh ro

Mi khonh b tng k thut hin trng phi tnh khi lng BT, khonh v vch ra bin php thi cng, tin cung cp v quyt nh thit b v nhn lc ph hp khi thi cng BT c lin tc m bo yu cu k thut cht lng thi cng b tng.

b) Cng ha mt Dng my i kt hp vi th cng o khun ng trong phm vi p p

trc. m bo chiu rng khun ng theo thit k. Th cng chnh sa khun ng v o mng dm nh pha ng theo ng cao v kch thc hnh hc theo h s thit k.

B mn C

4. T

Phnghin cphp thi cthi cng dca c hai

Ty cung ng

4.1.

Mt bo kh n

- T- Ch

- Kh

Bi thi cng. trnh.

s k thut

THI CNG

ng php u ngay tcng chnh di nc. i cch trn.

loi hnh vt t, thi

H

Chun b bng b t

nng thun p kt, bc h to cc ch nng di cha vt lii vi v

CTB&CT Ve

G M HNthi cng m khi thit

hay l hai Tuy nhin

.

cu to t b thi cn

Hnh3.27 :

mt bngr thi cngtin nht cxp vt li

cu kin; chuyn cciu phi t liu l

en bin

Tran

N, CHm hn hayk cng trcch tip c

n a s cc

, v tr xyng m la

: S xyg cng trn

g phi ph cho cng t

u xy dng

c phng tm bo hc c th

Bi gi

ng39

HN SNGy chn rnh. Hin cn chnh l cng trnh

y dng ichn ph

y dng phnh:

hp vi quc:

g cng trn

tin, thit bkh nng

h tp kt t

ng: K thu

G sng mi nay c ph

l thi cng h c thi

iu kin mng n thi c

ng n thi

uy trnh, th

nh;

b phc v tcung cp vti bi ngp

t TCCT bo

nghing ph bin hatrn cn tcng bi s

mi trng, cng ph h

i cng

hit b thi c

thi cng.

vt liu thep nc c

v b bin

phi c ai phng b ra v kt hp

kh nng hp.

cng m

eo tin chn cng


Trang40

Hnh 3.28: Quan h ga nhu cu cung cp VL v tin XD

4.2. Cc cn c la chn xy dng phng n thi cng 4.2.1. Thit b thi cng Vic la chn thit b thi cng l mt khu quan trng trong vic xc nh

gi thnh xy dng cng trnh. Cn c vo thit k chi tit, iu kin t nhin khu vc xy dng la chn thit b thi cng.

a) Thit b trn cn Cn cu: Cn cu lm nhim v cu, bc xp cc cu kin xy dng cng

trnh. Loi cu ph hp nht l cu bnh xch do kh nng n nh tt, khng cn chn chng ph v c kh nng di chuyn trong iu kin a hnh g gh phc tp thm ch ngp nc.

Kh nng nng ti danh ngha ca cu l kh nng nng ti ln nht m cu c th nng. Kh nng nng ti ca cu ph thuc vo tm vi ca cu, phng lm vic ca tay cu v kh nng gia ti ca cu.

My o: My o c th l loi gu thun hoc ngc. C th kt hp mt s thit b khoan ph u tay, c th thay i dung tch gu.

Xe i: Xe i thng dng loi bnh xch, dng san gt to phng mt Xe ti: Xe ti phn lm hai loi l loi chuyn ch vt liu trn ng v

loi chuyn dng trong cng trng.


Trang41

Hnh 3.29: Mt s thit b o, xc Bng: c im ca mt s loi thit b

b) Phng tin-Thit b ni Cn cu ni Cu ni c th l loi chuyn dng t hnh hoc n gin ch l cn cu

bnh thng gn trn s lan. Tnh n nh ca cu ph thuc vo s lan v trong qu trnh vn hnh cn phi m bo tnh n nh ca phng tin ni.

Hnh 3.30: Cu gn trn s lan

Tu ch VL: Tu ch vt liu c th l tu t hnh hoc s lan. Mt s loi tu chuyn

dng ch c kh nng t .


Trang42

Hnh 3.31: S lan ch

Hnh 3.32: Tu ch c cu t hnh

4.2.2. Vn chuyn Vn chuyn vt liu cn m bo tin cung cp vt liu cho cng tc thi

cng. Cng tc bc xp vt liu xung cc phng tin ni cn c nghin cu ngay t u cn c vo iu kin bn bi, mc nc, thit b bc xp.

Khi bc xp VL xung tu thuyn cn ch chnh lch do dao ng mc nc, do bin ng mn nc ca phng tin.


Trang43

Hnh 3.33: nh hng bin ng mc nc, ti hng ha

Hnh 3.34: Chuyn VL xung s lan

Hnh 3.3: Chuyn VL bng s lan

Vn chuyn ng b cc khi cu kin ln cn c cc phng tin chuyn dng ph hp.


Trang44

Hnh 3.36: Chuyn khi bng xe t 4.2.3. iu kin t nhin, mi trng khu vc xy dng - V tr, h tng khu vc xy dng Cn c s liu r rng v v tr cng trnh, h tng khu vc xy dng v h

tng lin kt khu vc ngoi cng trnh xem xt nh gi cng tc vn chuyn vt t, thit b, kh nng cung cp in nc...

- a hnh thc t khi thi cng: Do khu vc ven b a hnh lun bin i nn cn tin hnh o c kho

st li a hnh khu vc xy dng, m bo xc nh chnh xc a thc t khi thi cng.

- S liu mc nc: Cn c s liu mc nc triu, bin ng triu. Cn phi tnh ton d bo

bin ng mc nc triu trong sut qu trnh thi cng c phng n b tr thi cng hp l.

- S liu sng, dng chy: Cn iu tra, tnh ton v sng, dng chy khu vc xy dng. Cn kho st

o c v d bo cc s liu sng dng chy trong qu trnh thi cng cng trnh.

Hnh 3.37: D bo mc nc triu ti v tr xy dng


Trang45

4.2.4. nh gi ri ro Cng tc thi cng ven bin lun tim n nhng ri ro do c im ca mi

trng bin. Do cng tc nh gi, d bo ri ro l quan trng t a ra cc bin php phng ph hp.

Cn c thit b cnh bo nguy him khi thi cng. Trong qu trnh chun b thi cng cn nh gi ng nh hng ca cc yu t mi trng khng xc nh nh gi, triu, sng, dng chy...Ngoi ra cn quan tm n kh nng thay i ng b bin, y bin trong qu trnh thi cng cng trnh.

Nguyn tc qun l ri ro: a) Bo v cng trnh Cng trnh hon thnh hoc mt b phn cng trnh xy dng phi lun

m bo n nh trong iu kin bnh thng. Tuy nhin trong trng hp iu kin tc ng mi trng ln trong khi thi cng th cng trnh c th b h hi. Do cn c gii php ph hp d on v la chn bo v cng trnh khng h hi hoc h hi t.

b) Xc nh thi gian thi cng hp l v chnh xc Cn xc nh chnh xc thi gian thc hin xy dng cng trnh, t la

chn thi im thi cng, cng vic v tin thi cng hp l trnh cc cc ma c iu kin mi trng nguy him cho cng tc xy dng.

c) Gii hn cc iu kin hot ng ca phng tin, thit b Cc phng tin, thit b cn c gii hn hot ng r rng, cc gii hn

ny ph thuc khng ch tnh nng thit b m cn ph thuc c ngi iu khin.

d) Cng trnh tm phc v thi cng Cc cng trnh tm phc v thi cng cn c thit k vi iu kin mi

trng hp l. Thng thng nu cc cng trnh ny quan trng th c thit k vi chu k lp ca KMT l 10 nm.

e) Kh nng thay i ng b, y bin Ttong khi thi cng c th xy ra s bin i ng b bin, y bin lm

nh hng n kh nng tip cn, hot ng ca cc phng tin, thit b c bit l cc phng tin, thit b ni.

f) Thi gian thc hin d n g) Bo v ngi lao ng

B mn C

h) B

i) L4.3.

4.3.1

Phtrong khi lung lch

Cn - C

yu t mbit khc.

- V c ti v tr

- Vvt liu

- XD

- Khnng bn

a) L

Cmy o s

Cxung bn

Lkhi t trnh t

s k thut

Bo v mi a chn vPhng 1. Phng ng n tixy dng

h phi ph xem xt c

c iu kii trng d..

tr cng trr XD, ln

tr cc mng b raD cc b phh nng cunbi v lun

Lp li ng tc osp trn phng tc ng gu ngop li

x lan c trn x la

CTB&CT Ve

trng chu s dng pn thi cng

n thi cn

p cn t b cng trnhhp vi phc iu kin, yu cud bo tron

rnh, khu vcn khu v vt liu, ka v tr bn hn cng trng cp thing lch.

:

o y mnghng tin li c

om. khi th cth s dn

an cn xem

en bin

Tran

ung trong q

phng ting

ng t bin bin ph th. ng thhng tinn c thu ca cngng sut thi

c xy dnc xy dnkh nng ttp kt. rnh st b: s ph

Hnh 3.38

g, chn khni. Khi th th s d

th thi cng my kt

m xt cc y

Bi gi

ng46

qu trnh x

n thit b p

thuc rt lhi i hn thi cng..

thi cng g vic: thii gian d k

ng: s nh ng

tip cn c

u nc lh hp ca

8: S XD

hay c thhi cng cnng s lan

ng vi t hp th lu t sau:

ng: K thu

xy dng h hp

n vo ii h thng.

t bin: i im xy

kin xy d

hng ca

a cc ph

n: m ycc thit b

DCT

s dng tn ch khm y ho

chnh khln hon

t TCCT bo

u kin mg bn bi, c

y dng, ting, cc y

a cc cng

ng tin ch

y, chn kha

b vi cng

u quc k nng st noc bc t

ng i hn thin lp

v b bin

i trng cu cng,

n , cc u cu c

trnh hin

huyn ch

ay...

vic, kh

t hp vi n mi. s lan th

i cao, sau p li. Qa


Trang47

- Vn tc dng chy lc thi cng; - su th t mt nc; - c in li (kch thc , hm lng cc loi ); - Khi bng s lan x y cn phi xc nh mc nc thi cng hp l

m bo kh nng vn hnh ca s lan. Khi mc nc khng cho php th s dng my gu ngom.

Hnh 3.39: li bng s lan x y

- Khi c lp hc gia ti, phi th phn gia ti, sau th thn ln trn. - Khi cn p tri i vi nn th th t gia ln dn ra hai bn.


Trang48

Hnh 3.40: S lan x cnh

Hnh 3.41: li bng s lan x cnh

b) Lp gia c: Phi xt n nh hng ca sng, tin m bo ph kn lt trc khi

b xi. Trc lc lp t, cn kim tra tu sa b sung dc v tnh trng b mt lp lt, cn lm phng bng cch san ri nh lp cc khe ln. Sai s cho php, i vi phn thi cng trn nc khng ln hn 5cm, phn di nc khng ln hn 10cm.


Trang49

Hnh 3.42: Thi cng mi bng gu ngom ni

4.3.2. Phng n thi cng t t lin Phng n tip cn t t lin ph thuc rt ln vo kh nng tip cn khu

vc xy dng cng trnh bng ng b. Cn xem xt cc iu kin c th thi cng t t lin: - Cc iu kin, yu cu ca cng vic: thi im xy dng, tin , cc

yu t mi trng d bo trong sut thi gian d kin xy dng, cc yu cu c bit khc...

- V tr cng trnh, khu vc xy dng: s nh hng ca cc cng trnh hin c ti v tr XD, ln cn khu vc xy dng

- V tr cc m vt liu, kh nng tip cn ca cc phng tin chuyn ch vt liu ng b ra v tr bn tp kt.

- XD cc b phn cng trnh su nc ln: m y, chn khay... - Kh nng cung cp thit b: s ph hp ca cc thit b vi cng vic...


Trang50

Hnh 3.43: li bng xe vn ti

Hnh 3.44: Thi cng mi

Hnh 3.45: Cu lp v theo di lp t khi ph di nc


Trang51

Hnh 3.46: Thi cng khi ph

Hnh 3.47: Thi cng khi ph

4.3.3. Phng n thi cng kt hp y l phng n thi cng kt hp dng c phng php tip cn t bin

v t b. Phng n ny cho php la chn thit b thi cng a dng hn, khc phc c cc hn ch ca c hai phng n l tip cn t bin v t b.

4.3.4. Yu cu k thut Cc khi ph cui dc phi m bo tip xc cht ch vi lng th

chn . Dng khi dolos hoc tetrapod ph mi m bo mt ng u trn ton mi.


Trang52

Hnh 3.48: S lp t khi dolos trn mi nghing

Hnh 3.49: Phng php lp t khi terrapod trn mi nghing

a. Mt ct ngang; b. Mt bng - Cch lp t khi dolos: cch t ng pha di dc v ln cnh

nm ngang ca khi pha di , cch t ngang ln lp mi . Thanh ni vt qua cnh ngang ca khi ln cn sao cho lt di khng l ra ( hnh 9.2).

Sai s lp t cu kin c quy nh nh sau - i vi khi dolos v tetrapod: s lng lp t thc t so vi thit k

khng sai lch qu 5%.


Trang53

- i vi tm khi vung : chnh lch cao so vi khi ln cn khng qu 15 cm, khe lt gia hai khi khng ln hn 10cm.

Hnh 3.50: S kim tra lp t khi gia c trn mi nghing

Bng 3.1: Sai s cho php i vi ng vin mt ct thit k ca . Trng lng th(kg) 10100 100200 20030

0 300500 50070

0 7001000

Chnh lch cao cho php(cm)

40 50 60 70 80 90

Bng 3.2: Chnh lch cao cho php gia ng vin thc t so vi thit k

i vi trng hp ph mi bng hc lt khan


Trang54

Nn chn vin tng i gn vi lng tr, chiu di khng nh hn chiu dy thit k. Vin t dng ng, trng lng khng nh hn trng lng thit k. Lp ph bng hc cn t cc yu cu sau :

- Trn 90% din tch bo m dy thit k; - Khe rng gia hai vin lt khng ln hn 2/3 ng knh b nht ca

lt pha di, khng tn ti khe lin thng vung gc vi mt lp ph: + Chiu rng khe ghp cho php : 3 cm; + Chiu rng khe tam gic cho php: 7 cm; + nhp nh mt mi cho php : 3 cm; - lt khan cn chn cht, nh c gi pha di, dng x beng by

mt vin ln ri khi mi th 2- 3 vin xung quanh cng b by ln. Xy cn t cc yu cu cho php sau: - Mch xy : 4 cm - rng khe tam gic: 8 cm - li lm mt mi : 3 cm

B mn C

5. TLC

Phc nghxy dng la chn p

5.1.

B kh nng

Cnhin bngnn c b

s k thut

THI CNG

ng php in cu ng iu ki

phng n

H

Phng c thvt liu

ng tc kimg th ln dit hoc c

CTB&CT Ve

G M HN

thi cng mgay t khi tn mi tr thi cng p

Hnh3.27 :

n thi cng

hi cng m b tri dtm tra pha trn h

c m dn

en bin

Tran

N, CH

m hn hathit k cng, kh nph hp.

: S xyg b m bo pt do dng c

hng ca bga ngm.

ng trng lc

Bi gi

ng55

HN SNG

ay chnng trnh. Tng cung

y dng ph

phng, c chy v sn mt y B c th t tr

ng: K thu

G TNG

n sng tTy loi hng vt t,

ng n thi

chc. Khing.

m ngc m chn tu.

t TCCT bo

G NG T

ng ng cnh cu tothit b thi

i cng

i thi cng c

gp nc t bng thi

v b bin

TRNG

cng phi o , v tr i cng m

ch n

c thc it b m


Trang56

Hnh 5.1: Thi lm phng cng b

Hnh 5.2: Thi cng m hc


Trang57

Hnh 5.3: Mt s dng thi cng m hc 5.2. Thi cng khi thng chm Thng BTCT thng c thi cng trn b, trong ni hoc trn s lan.

Ty tng iu kin c th chn cch thi cng. - Thi cng trn b: thng dng vi cc thng c kch thc, trng lng

nh do kh nng hn ch ca phng tin cu, vn chuyn v h thy. - Thi cng trong kh: Thng dng vi cc thng c kch thc v trng

lng ln, c tnh n nh v t ni cao trong qu trnh vn chuyn ko ra v tr lp t.

- Thi trn s lan ( ni): Thng dng vi cc thng c kch thc v trng lng ln, c kh nng n nh v t ni trong qu trnh ko vo v tr lp t.

Ty tng iu kin c th l chn bin php thi cng ph hp. Khi thi cng h thy, vn chuyn v nh chm cn tnh ton cc bi ton

la chn thit b thit b hp l: - La chn cu vn chuyn, h thy cu kin: Cn cn c vo kh nng nng - tm vi ca cu v kch thc trng

lng ca thng BT la chn phng n cu ph hp.


Trang58

Hnh 5.4: Quan h tm vi v sc nng ca cu - La chn tu lai dt: Khi vn chuyn lai dt thng BT (t ni, ch bng s lan) cn xc nh

lc ko ca tu lai dt. Cn ch n cc nh hngr ca dng chy, sng n cng tc lai dt.

Cn kim tra kh nng t ni v n nh ca thng khi ko thng ra v tr tp kt ti cng trnh v nh chm vo v tr xy dng. Nu ko thng trn qung ng di th nh ca thng i hi cao hn l ch bng s lan ra v tr xy dng.

Hnh 5.5: n nh ni thng chm BTCT - La chn s lan, ni: S lan, ni c cc cu kin trn boong cn phi m bo kh nng

chu ti ca mt boong khi cng cc thng trn boong. Cn xc nh thi gian thi cng trn s lan mt cch chnh xc b tr

thit b v la chn v tr neo u ph hp.


Trang59

Hnh 5.5: Thi cng lp t thng chm BTCT Cn d bo, xc nh kh nng thay i mc nc bin, mn nc thi cng

trong sut qu trnh thi cng trn bin.

Hnh 5.6: Lai dt thng chm vo v tr xy dng

Cng tc thi cng cn c tnh ton d kin ngay t khi thit k. La chn c phng n hp l thi cng s m bo tnh kinh t k thut ca cng trnh.

tc cong trinh bvbb-01

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