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TIU CHUN NGNH Nhm H

CNG HO X HI CH NGHA VIT

NAM

CU V CNG Quy phm thi cng

v nghim thu

22TCN 266 -2000

B GIAO THNGVN TI C hiu lc t 09 / 9/ 2000

Ban hnh km theo quyt nh s: 2453 /2000/Q-BGTVT, ngy 24 / 8 /2000. Thay th Quy trnh thi cng v nghim thu cu cng ban hnh km theo Quyt nh s 166/Q nm 1975.

1. CC QUY NH CHUNG

1.1. Cc yu cu ca quy phm ny phi c thi hnh i vi tt c cc t chc

t vn thit k, t vn gim st v cc nh thu khi thi cng v nghim thu cc cu cng xy dng mi vnh cu hoc ci to (trong bao gm ng ng, mng nc, cu tu bn cng, cu vt cn, cu dnh cho ngi i b) thuc ng st, ng tu in, ng t (gm c ng ni b ca cc x nghip v t chc nng nghip, ng ca cc x nghip cng nghip) trong v ngoi th, nu nh n bn v thi cng khng quy nh cc yu cu khc. Nhng hng mc thi cng v nghim thu khng c quy nh trong quy phm ny, phi thc hin theo ng ch dn ca n BVTC.

1.2 Khi thi cng cu v cng, ngoi cc yu cu ca quy phm ny, phi tun th

cc yu cu trong danh mc cc tiu chun nh nc, tiu chun ngnh v cc tiu chun khc c lin quan, trong bao gm c v an ton k thut, v sinh cng nghip v phng chy, nu trong ph lc 2.

1.3. Nhng qui nh ca quy phm ny da trn mt s tiu chun, qui phm hin

hnh ca Nh nc. Khi c khc bit gia qui phm ny v tiu chun, qui trnh lin quan khc v vic thi cng v nghim thu cu cng th phi tun theo quy phm ny.

1.4. Khi xy dng cc cng trnh cu v cng phi thc hin cc gii php thit

k, bo v mi trng sinh thi theo qui nh hin hnh. Cc gii php k thut c p dng phi ph hp tiu chun v sinh cng nghip

v khng cho php gy bn nc mt v nc ngm, khng c lm ly li khu vc cng trng, khng c sn sinh ra cc cht c hi cng nh khng cho php a cc cht thi khc ra ngoi tri gy nhim mi trng.

Nghim cm vic cht ph rng hoc cy ci vng ph cn cng trng xy dng: khng rc thi hoc vt liu xy dng ln mt t khu vc xy dng lm suy thoi thm thc vt cng nh vic tho nc ra ngoi sao cho khng lm thay i mc nc ngm sn c.

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Trc khi bn giao tr li mt bng cng trng bc vo khai thc cng trnh, phi tin hnh tho d cc nh tm ln tri v cc cng trnh ph tr, thu dn sch vt liu v cc cu kin cn tha, sa sang li mt bng, cng nh phi thu dn thanh thi lng sng di cu v khi thng cc l thot nc trong cng.

1.5. Vic xy dng cc cu ln v cu va phc tp th nht thit phi do cc nh

thu xy dng cu nng lc m nhn. 1.6. Vic xy dng cu v cng phi thc hin u tin bng phng php cng

nghip do ng dng cc kt cu v chi tit lp ghp. Vic t chc thi cng phi to iu kin sao cho t nng sut lao ng cao, m

bo c th bn giao cc cng trnh xy dng t tin nh, cng nh bo m cht lng thi cng cao v gi thnh r nht.

1.7. Trnh t thi cng v thi gian hon thnh cc cng tc xy dng v lp rp

phi c quy nh bng biu tin . Cc biu tin ny phi th hin c cc dy chuyn sn xut v s kt hp cc mi thi cng khc nhau.

Cng tc xy dng phi c tin hnh u n trong c nm. Mun vy ti cng trnh phi to ra cc khi lng d tr, khin cho cng tc trong ma kh v ma ma tin hnh bnh thng, khng phi tng cng nhn lc v nng cao gi thnh ln nhiu.

1.8. V cn bn, cc b phn ca kt cu lp ghp phi c ch to sn trong

xng my chuyn nghip. Khi no khng th ch to cc kt cu ti xng my chuyn nghip hoc khi vic chuyn ch cu kin ti cng trnh khng li v mt kinh t th n v thi cng phi lp bi ch to ring gn vi quy m v s lng, chng loi thit b do khi lng cng tc quyt nh.

1.9. n v thi cng phi hn ch s lng cng trnh tm trong cng trng ti

mc ti thiu v phi u tin dng cc kt cu tho lp vn nng, cc kt cu c th lun chuyn c lm cc cng trnh tm .

1.10. Cc cng tc xy dng v lp rp cn c c gii ho ti mc ti a v i

vi cc hng mc cng tc ln phi ng dng phng php c gii ho ton b. 1.11. Cc vt liu xy dng v cc kt cu, c bit i vi loi c khi lng ln,

phi a thng ti cc kho ti cng trng, khng qua chuyn ti. Cc kho ti cng trng phi c b tr vng hot ng ca cc thit b cn trc v phng tin vn ti phc v cng trng .

Nu vt liu xydng ch yu ca cng trnh l b-tng, phi lp phng th nghim vt liu ngay ti cng trng.

1.12. Cc gii php thi cng, trnh t v thi hn thi cng c xc nh trn c

s xt tnh n chu k v mc nc hng nm, cng va p ca sng, xi l lng sng, s va p ca vt tri, cy tri v.v...

Khi xy dng cu vt qua sng c dng chy mnh hoc c tu thuyn qua li, phi tun theo cc quy nh v m bo an ton giao thng ng thu ni a, cng nh

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m bo hot ng ca tu thuyn nh bt c, to iu kin thun li cho vic di chuyn n c.

Khi trin khai xy dng cc cng trnh v thit b ph tm thi cng trn mt sng c p bao, phi m bo n nh tuyt i cho trong khu vc lm cu v phi tun theo cc quy nh v bo v iu.

1.13. Khi chun b vt liu ti ch (, ct , g xy dng) ti chn cng trnh, phi

kim tra nghim ngt v cht lng v c tnh ca vt liu theo tng l khi lng, phi xem xt yu cu c th cho tng loi vt liu thch hp.

1.14. Sau khi bn giao cu v cng cho c quan khai thc qun l, nh thu xy

dng phi c trch nhim quan st tnh trng k thut ca cng trnh v kim tra v tr cc b phn kt cu theo mt bng v mt ct dc trong thi gian bo hnh, c bit l sau ma nc l.

Nh thu phi quan st k cc cng v kim tra v tr tng t cng sau 2 - 3 thng lp t xong di t.

Kt qu ca cc cuc kim tra phi c ghi r vo vn bn lu tr theo di. 1.15.Vic cht ti ln cc b phn cu c hon chnh theo n, ch cho

php sau khi kim tra v lp bin bn nghim thu cng on . Trnh t ch dn v cht ti phi c ch cng trnh chp thun.

1.16. Khi b tr cng trng xy dng, iu ng kt cu cng trnh ph tm v

my thit b thi cng, phi m bo an ton vi mc nc l xut hin trong sut thi gian thi cng; c th chn mc nc cao tng ng vi lu lng tnh ton dng chy c tn sut 10%.

Nu c c s v iu kin k thut - kinh t thch hp, cho php ly mc nc thi cng tng ng vi lu lng tnh tan c tn sut 50%.

2. CNG TC O C NH V

2.1. thc hin d n xy dng cu (cng), cn phi lp mng li o c sau: a) Mng li tam gic c, a gic c hoc ng sn - tam gic (i vi cu

di trn 300m, cu treo dy xin, cu trn ng cong hoc cu c tr cao hn 15m). b) Chi dn mc (trng hp a hnh phc tp, cc im o ca mng li

khng nhn r nhau c th trn tim ca im o cn phi lp chi dn mc c cao cn thit).

c) Cc im o dc theo tim cu (i vi cng l im giao ca tim cng v tim ng)

d) Cc im o dc theo trc tim ph song song vi trc tim chnh ca cu, trong trng hp xy dng cu vt qua bi sng c di hn 100m, khi xy dng cu trong cc iu kin phc tp (an xen vi cc kin trc sn c hoc bo tn thin nhin) v trong trng hp cc im o c th b h hng trong qu trnh thi cng cu.

e) Cc im o tim ng vo cu, trong trng hp phn ng vo cu cng nm trong khi lng thi cng ca d n cu.

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f) Cc im o tim tr trn bi sng ca cu c chiu di hn 100m, cu treo dy xin, cu trn ng cong hoc cu c tr cao hn 15m.

2.2. Vic lp mng li o c phi c xt thch hp sao cho t cc im o c

th xc nh c tim tr v kim tra v tr kt cu trong qu trnh thi cng. Nu tim cu ct qua mt khu t cao, nht thit phi lp thm t nht mt im o

ph trong mng li o c nh v tim cu v mt chi dn mc. Nu tim cu nm trn ng cong, cn bm st theo hng ca dy cung xc

nh im u v im cui cu. Trong trng hp b tr on cu vt sng nm trn ng thng, cn on cu dn nm trn ng cong, khi on cong chuyn tip ca cu bm st theo ng tang.

2.3. i vi cc cu c chiu di trn 300m, cc cu treo dy xin, cu trn ng

cong cng nh cu c tr cao hn 15m, cn phi lp bn v thit k mng li o c (ML) nh v kt cu v kim tra thi cng cu; bn v c lp trong h s thit k t chc xy dng cu.

i vi cc cu cn li v cng, cng tc o c bao gm vic lp s v tr im o nh v kt cu v xc nh c ly, cng nh nhng yu cu v chnh xc tng ng vi my - thit b kim tra trong qu trnh xy lp, phi c xem xt trong n bn v thi cng (BVTC).

2.4. Trong bn v thit k ML, cn nu thm nhng yu cu phc v thit k

t chc xy dng (TCXD) v thit k BVTC nh sau: Giai on chun b xy dng: s b tr cc im o v biu tin hnh cng

tc o c . Giai on thc hin xy dng: cc d kin v chnh xc v phng php thit

lp mng li o c cu, s b tr v xc nh im o trong mng li; dng cc tiu, cc mc; cc d kin v chnh xc, phng php, my - thit b o v trnh t trin khai chi tit cng vic o c, s o kim tra v thc hin php o; biu tin hnh cng tc o c.

Giai on kt thc xy dng, a cng trnh vo khai thc s dng: theo di quan st s chuyn v v bin dng ca cng trnh, phi c cc d liu v chnh xc, phng php, my - thit b o v trnh t theo di chuyn v - bin dng ti hin trng; s mng li o c, cc d kin v chnh xc ca cc php o kt cu, dng cc tiu cc mc; biu tin hnh cng vic o c.

Trong bn v thit k ML, cng cn ch r my o v cc php o chun. 2.5.Ton b bn v thit k ML do t chc t vn thit k lp phi c chuyn

giao bng vn bn cho bn nh thu tip nhn cng tc o c v nh v kt cu cng trnh.

Bin bn nghim thu ML phi c s ho mt bng v tr cc tiu cc mc khu vc lm cu, dng v su chn cc, to cc, k hiu v cao mc trong h thng to v cao trnh nh nc.

i vi cc cu c chiu di trn 300m, cc cu treo dy xin, cu trn ng cong, cng nh cu c tr cao hn 15m, trong bin bn nghim thu ML c bn v mt

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bng khu vc cng trnh, trong c v tr v cao trnh cc tiu cc mc, km theo nhng ch dn cn thit thc hin cng tc o c.

2.6. Cng tc o c nh v trong qu trnh t chc xy dng cu v cng, vic

phn nh tim ng nhnh tm thi, vic lp thm (nu cn) mng ng sn cho cu ngn hn 300m hoc cu vt qua dng chy c b rng nh hn 100m, cng nh mi cng vic kim tra o c khi tin hnh xy lp, u phi do nh thu thc hin. Nhng d kin v to cc tiu cc mc trong ML phi do ch cng trnh cung cp.

2.7. Khi tin hnh t chc xy dng cu, cn kim tra cng tc o c theo cc

cng on sau: a) Trc khi lm cu, tun th cc quy nh ca iu 2.5. b) Sau khi lm xong phn mng m tr (trc khi bt u xy thn m tr). c) Sau khi xy m tr cu (sau khi lm xong phn mng m tr) d) Thc hin cc bn v thit k ML trong qu trnh xy thn m tr e) Sau khi xy xong m tr v nh tim dm trn mt k gi f) Sau khi lp t kt cu nhp vo v tr gi . 2.8. Nhng yu cu k thut, khi lng v phng php cng tc o c c

ch dn trong bng 1. Bng 1

Yu cu k thut i tng kim

tra Phng php

hoc cch thc kim tra

1. S lng cc tiu - cc mc trong mng li o c i vi cu di trn 300m, cu treo dy xin, cu trn ng cong, cu c tr cao hn 15m, cng nh cu vt qua dng chy c b rng mt thong trn 100m, thc hin theo bn v thit k ML.

Tng cc

Dng trc c (tin hnh o khi nghim

thu ML)

2. S lng cc mc v cc tiu trn mt bng mng li o c dc theo tim cu c quy nh:

+ i vi cng v cu c chiu di nh hn 50m n 300m, 1 mc cao c v khng t hn 2 cc tiu mi bn b.

Tng cc mc v cc tiu

Dng trc c (tin hnh o khi nghim

thu ML) + i vi cu di trn 300m, cu treo

dy xin, cu trn ng cong v cu c tr cao hn 15m: 2 cc mc v khng t hn 2 cc tiu mi bn b.

nt nt

3. Sai s qun phng (mm) qui nh: + to cc cc theo mt bng mng

o c s, l 6

Ton b cc tiu trn mt bng o

Dng trc c (tin hnh o theo mt

bng phng). + cc mc cao c trn b v trn Ton b cc mc Dng trc c (o

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mt m tr: mc lu di l 3, mc tm thi l 5.

cao trnh theo hnh hc hoc lng gic, dng my ton c

in t.

Ghi ch: 1. Trn cc cu di hn 100m, cu treo dy xin, cu trn ng cong v cu c

tr cao hn 15m, cc cc tiu cc mc ca ng sn c bn u bng BTCT, trn mt cc c gn im tim m bo mng li o chun xc. Trn cc cu khc cn li, cc cng v ng vo cu cho php s dng cc g c u inh thp lm ng sn c bn.

2. Khi ng vo cu nm trn ng cong, cn phi xc nh: im u v im cui ca ng cong, im phn gic v nh ng cong.

3. Mc cao c c b tr cch ng tim cng trnh khng qu 80m, nhng phi nm ngoi phm vi nn p, thng u, rnh thot nc,v.v...

4. quan st chuyn v v bin dng ca cc m tr cu (i vi cng trnh c ghi trong bn v thit k ML), cn phi nh du c nh im o trn mt bn m thp gi cu thng h lu hoc gn cc s c u hnh chm cu (trng men) ln nh m tr v tr thun tin t thc o ngm.

2.9.Khi xc nh khong cch gia cc mc nh v tim cu v cc tr bng

phng php trc c th mng li a gic cn phi p ng cc yu cu sau y:1. Tu theo iu kin a hnh

chn dng ca mng li cn c (hnh 1) nh sau:

i vi cc cu ln dng mng li a gic c, khi c bi ni gia sng th dng mng li trung tm.

i vi cu va, dng mng li ca 2 hoc 4 tam gic.

2. Gc ca hnh tam gic khng c nh hn 250 v khng ln hn 1300 cn trong a gic c th khng nh hn 200.

3.Mng li chung phi bao gm t nht l hai im c bn nh v tim cu, mi bn b c mt im, ngoi ra cn phi bao gm tt c cc im m t c th nh im tm cc tr bng cch giao tuyn thng v c th tin hnh kim tra trong qu trnh thi cng.

Trong trng hp ny giao nhau gia hng ngm v tim cu cng gn 900 cng tt, cn chiu di tuyn ngm (t my o ti tr) khng c ln hn:

Hnh 1: Cc dng ca mng li

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1000m khi nh im bng my

kinh v c chnh xc v s c l 1 giy.

300m khi nh im bng my kinh v c chnh xc v s c l 10 giy.

100m khi nh im bng my kinh v c chnh xc v s c l 30 giy.

S lng giao im bn sn khng c t hn hai im

4. Cc im ca mng li tam gic cn phi c ng bng cc c nh. Trong hon cnh a hnh phc tp, nu di t khng nhn r nhau c th trn tm ca im o cn phi dng chi dn mc c cao cn thit (hnh2).

Hnh 2: Chi dn mc v cc chi tit ca chi

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Trc mi ln ngm my phi dn tim ca mc ln ca my ngm. Nu khng

th dn tim ca mc ln ca my ngm th cn xc nh cc yu t quay v tm v i chnh cho thch hp.

5. Trong trng hp chiu di cu di 200m th trong mng li tam gic cho php o bng 1 c tuyn, cn nu chiu di ln hn th t nht phi o bng 2 c tuyn. Trong trng hp sau, cc c tuyn c cm mt bn b thng lu v h lu cu hoc hai bn b mi bn mt c tuyn. C tuyn phi c cm trn ch t phng c dc nh hn 1%. Trong trng hp c bit cho php cm mt mng li c tuyn c lp.

2.10. Chiu di ca c tuyn phi o vi chnh xc quy nh bng 2 v chnh

xc gp 2 ln so vi khi o khong cch gia cc mc nh v tim cu. Trong bng 2 cng ra chnh xc cn thit khi o gc v khp cho php i vi mi tam gic ca mng li trc c. Ngoi ra trong cng ra cc dng c cn dng o.

Bng 2

YU CU V CHNH XC KHI O C TUYN GC V CC DNG C CN THIT.

Chiu di ca cu

(m)

chnh

xc cn thit khi

o

chnh

xc cn thit khi o gc (giy)

khp cho

php trong cc

mng (giy)

Cc dng c cn dng o v s ln khi o gc

- Nh hn 100 - T 100 n 300 - T 300 n 1000

- Ln hn 1000

1/10.000

1/30.000

1/50.000

1/80.000

20

7

3

1,5

35

10

5

2

-Thc thp hoc thc cun. my ton c 30 vi 2 ln quay vng. - Thc o hoc thc cun c khc ly my ton c 10 vi 3 ln quay vng . - Thc o thp hoc my o quang in, my ton c 1 vi 3 ln quay vng. - My o quang in, my ton c 1 vi 5 ln quay vng.

2.11.Vic nh cc tim tr cu trn mt ng thng cn tin hnh bng phng

php giao im vi gc vung t nht l t 2 im ca h thng a gic c v t cc tim tr trn ng tim cu vi lch cho php ln nht l 15mm. Vic nh v cc b phn ca tr sau ny cn tin hnh t cc tim ca tr bng cch gin n, u tin l bng phng php ta vung gc.

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Trong qu trnh xy dng cn phi thng xuyn kim tra v tr ca tim tr. 2.12.Trong qu trnh xy dng mng v thn tr cu cn phi t trc nhng mc

cao c ph ngay ti nh tr, mc thp v mc cao nhanh chng xc nh c cc cao im cn thit cho vic xy dng tr hoc lp rp dm cu .

t cc mc cao c ph phi i cao c 2 ln t nhng mc chun vi sai s cao c nhiu nht l 15mm.

2.13. Ti cu di trn 200m phi t: a) Trn thnh ca mi m: mc cao c theo mu quy nh.Gia cc mc vi

nhau v vi cc mc chun phi i cao c t nht l 3 ln, vi sai s bnh qun 10mm. b) Trn cc m tr: mc cao c cc ni thun tin cho vic t thc ngm Trn cc tr sa cha li m trc y quan st thy c bin dng hoc ti cc

tr lm mi trong iu kin a cht phc tp, phi trong cc hm kn, mi tr 2 ng thu bnh t vung gc vi nhau. Mi ng thu bnh ny c khc kim tra nh hn 20 giy. Trc khi bn giao cho s dng, nh thu thi cng phi tin hnh cho xong vic kho st ln v bin dng bng mc cao c v bng ng thu bnh.

2.14.Khi sa cha cc cu sn c v khi phc cc cu b h hng phi xc nh

trng thi v v tr ng tim dc, ngang ca cc tr b ph hoi v kim tra khong cch gia cc tim tr, i chiu vi cc s liu thit k .

2.15.Tt c cc s liu o c c u phi ghi vo cc s cng tc hin trng

theo mu quy nh ring, cn mi tnh ton u ghi vo nhng biu mu hoc vit thnh vn bn r rng .

Tt c cc s cng tc hin trng, cc h s v cc s liu vn phng, trong qu trnh hon thnh, phi c kim k li, ng gi v a v phng k thut thi cng bo qun.

3. CC CNG TRNH V THIT B PH TR

3.1 Cc kt cu cng trnh v thit b ph tr (CTTBPT) thi cng cu phi thc hin

ng cc yu cu ca tiu chun ngnh Qui trnh thit k cc cng trnh v thit b ph tr thi cng cu v nhng qui nh trong phm vi ny.

3.2 Khi thi gian s dng cc kt cu bng g khng qu 5 nm, cho php khng

cn n cc bin php phng chng mc mt. 3.3 Khng c cht ti trng khc ln CTTBPT m trong thit k BVTC khng

qui nh. 3.4 Nu b tr CTTBPT trn sng c vi phm hnh lang thng thuyn, cn phi lp

t cc bin bo tn hiu v cc kt cu bo v c bit, trnh c s va chm ca tu thuyn.

3.5 Khi lm tr to nn lp t CTTBPT, cn phi c bin php sao cho phn

nn pha trn mt nc.

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Cng vic o t gn xung quanh tr ny cn phi tun theo ch dn ca thit k TCXD.

3.6. Vic lp t cc tr v dm tm, nu khng c cc ch dn c bit ca

thit k, cn c d phng ln do pht sinh bin dng d trong cc trng hp sau: p cc b mi mt tip gip gia g v g, l 2mm; p cc b mi mt tip gip gia g v thp l 1mm; Lp t nn m cht,d phng ln l 10mm; Lp t c ct hoc t ct, d phng ln l 5mm. 3.7. Vic to bi lp t kt cu nhp trn nn ng vo cu phi tin hnh p t

dn tng lp m cht theo yu cu ca n thit k. Mt bng p t phi m bo tiu thot nc nhanh. Trc mi t c m hoc y m v sau mi trn ma ro cn phi o li cao

trnh mt bi v khc phc cc bin dng pht sinh. 3.8. Mt trn ca ng trt ln phi st kht vi mt di ca m bin dm khi

lao y sao cho khng c nhng chi tit b phn no li cm ln. 3.9. Khi lao ko kt cu nhp trn ng trt ln, khng cho php dng nhng con

ln c ng knh khc nhau v c cc khuyt tt nh mo van, cn xc, st m hoc mn u. Mt ca ng ln khng c g gh, mi hn hoc cc chi tit khc li ln phi c ty bng.

3.10. Tc lao ko dm trn con ln khng c vt qu 30m/h, cn trn tm

trt, khng qu 15m/h. Tc hnh trnh ca pit-tng kch y dm theo hng ngang khng c vt qu 5mm/s.

Trc khi tin hnh lao ko dm, tt c cc vt liu thit b dng chng ko u phi c kim tra k lng v ghi vo bin bn nghim thu.

3.11. Khi thi cng c s dng h ni, phi kho st v thm d trc phm vi hot

ng ca h ni di nc m bo su nc di y h n ln hn 0,2m. 3.12. H ni dng trong thi cng l cc phao thp ni ghp hoc s lan thp. Trc khi lp t h ni mi phao thp hoc s lan phi c ng kim v c ghi

vo bin bn nghim thu. 3.13. Khi di chuyn h ni bng h ti ko hm phi b tr sn cc im neo d

phng v chun b sn cc thit b thay th chng buc cp ln thn h ni c d dng. 3.14. cc gc cnh ca h ni phi gn thc o vch sn r rng o

mn nc trong sng. Khi cht ti trn h ni phi thng xuyn kim tra ln lch ca h i chiu vi tr s thit k.

3.15. Trc khi v trong sut qu trnh s dng h ni lm vic trn mt sng, phi

c y thng tin v d bo thi tit thu vn trong thi gian tin hnh cng vic.

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3.16. i ch huy trn h ni phi c trang b b m in t lin lc vi b phn iu khin h ti ko hm, tr ni v vi b phn iu hnh trn b.

3.17. Khi vn hnh my cu t trn h ni phi m bo tnh n nh vng, cho

php my cu hot ng thi cng khi c gi vi vn tc khng qu 10m/s v khi c sng n cp 2 (vi chiu cao sng nh hn 25cm).

3.18. i vi my cu kiu cng t hnh v my cu kiu chn d khng c ng

ray dn, phi m bo tr s chnh lch ca chn cu khi di chuyn khng c vt qu 1/500 chiu di cn vi ca cu.

3.19. Ct s dng trong CTTBPT thi cng cu, nu khng c yu cu c bit khc

phi m bo sch, kh, ng knh ht qua mt sng t 1 n 1,2mm. Ct phi c bo qun tt, khng b ng nc hoc ngm nc.

3.20. Kch dng trong thi cng cn phi m bo lm vic theo hng ng tm,

vic iu chnh ch lm vic ca tng kch hoc nhm kch phi cn c vo ng h o p lc; dng kch y phi c thit b hm (d phng); khi kch ta trn mt thp th phi lt tm m bng g, khi ta trn mt g th lt m thp phn b lc.

Khi kt cu nhp t ln mt kch phi t bn thp m gia phn b lc. trong mi trng hp khc, phi c lp m gia bng g dn t trn mt kch.

Khi kch chu lc, phi m bo trng tm ca lc ln kch trng hp vi ng tim hnh trnh ca pit-tng.

3.21. Phi lp cng v tin hnh th ti cc CTTBPT trc khi a vo s

dng thi cng cu. 3.22. Trc khi a cc CTTBPT vo thi cng cu, cn phi t chc kim tra,

nghim thu v lp thnh bin bn. Danh mc cc CTTBPT cn nghim thu, theo ch dn ca n BVTC.

3.23. Trng thi ca cc CTTBPT phi c kim tra theo di trong qu trnh thi

cng cu. Vic quan st v kim tra CTTBPT phi c thc hin trc khi chu ti v sau khi vn hnh trn sng nc.

3.24. Cc yu cu k thut, hng mc v phng php kim tra cc CTTBPT trong

qu trnh trin khai thi cng cu, c quy nh theo bng 3. Bng 3

Yu cu k thut i tng

kim tra Cch thc kim tra

1. sai lch v v tr so vi n: i vi kt cu thp, theo mt bng,

khng qu 30mm.

Tng kt cu

o bng thc

i vi mi loi hnh kt cu, xin theo hng thng ng khng qu 0,0025.

nt nt

i vi mng cc, qui nh theo bng 5. nt nt

12

2. sai lch v cao trnh ca kt cu g v kt cu thp, khng qu 50mm.

nt nt

3. sai lch v ng bao hnh hc ca dm v gi , khng qu +20mm v -10mm

nt

o bng my thu bnh.

4. song song ca ng ln trt di khng sai chnh qu 25mm.

Tng kt cu o bng thc

5. chnh cao Theo mt phng ca ng ln ring r,

khng qu 1mm.

nt o bng my (cch 2m mt im o)

Theo hai im ta ln khng qu 2mm nt o bng my (cch 1m

mt im o). 6. chnh ng knh cc con ln thp

trn mt tr ta, khng qu 0,3mm. Tng con ln o bng thc kp

7. lt kh ca phao ng kn khi th, gim i khng qu 0,1At

Tng phao o bng ng h p lc th theo qui nh ng

kim

4. CNG TC CT THP V B-TNG

4.1. Khi tin hnh cng tc ct thp v b-tng phi tun theo cc yu cu ca Tiu chun nh nc Kt cu b-tng v b-tng ct thp ton khi - quy phm thi cng v nghim thu v cc qui nh ca qui phm ny.

CNG TC CT THP

4.2. Trong trng hp ct thp si cng cao c lm gia nhit, vic th nghim kim tra tnh nng ca si thp ch tin hnh sau khi gia nhit xong.

4.3. Khng cho php dng h quang in ct si thp cng cao, dy cp thp v thanh thp chu lc; khng cho php dng hi hn ct cp thp c bc; cm vic hn st gn vo ct thp chu lc m khng c bin php bo v ct thp ny khi s tc ng ca tng nhit v tia la; khng cho php dng ct thp chu lc lm dy dn mch ca my hn in hoc lm dy tip t cho mt my in.

4.4. Trong trng hp n BVTC quy nh ni buc ct thp sn v li thp

bng tay, th khng c php dng cch hn nh. 4.5. Si thp cng cao, dy thp bn, cp thp v cc loi ct thp khc dng

trong kt cu b-tng phi c chn theo ng chng loi yu cu ca n thit k, phi c lu gi trong nh kho kh gio v thong gi; phi c bin php chng g cho cc loi ct thp trong mi trng khng kh m.

Khng cho php di chuyn cc b hoc cun thp mt cch tu tin, gy nn tnh trng un gy, h hng hoc lm bn ct thp.

Khi vn chuyn ct thp nguyn kin v ct thp ch to sn thnh sn, phi chn phng tin thch hp vt liu khng b t, bn hoc dnh, cc loi ho cht c mui v a xt.

13

4.6. Tt c vng neo phi c lau chi sch khng cn du m v khng c lm

hng cc rnh ren, trc khi lng t vng neo vo cc b ct thp; tt c cc li neo cng phi c lau sch v kh b mt li trc khi ng vo vng neo.

4.7. Trc khi lp t ct thp chu lc lin kt sn a vo vn khun, phi tin

hnh nghim thu v lp bin bn. Trong qu trnh lp t ct thp, khng cho php hn nh (hoc buc) ct thp

chu lc vi cc loi ct thp phn b, cc ct ai v vi bn thp m gi cng nh vi vn khun hoc cc chi tit khc.

Phi dng trc tip kh nn thi sch nc v cht bn bm vo khe rnh vn khun, trc khi t lng ct thp chu lc vo bn trong vn khun .

i vi ct thp c cng trc trn b, cn lu chng g cho ct thp ny trong thi gian cha b-tng. i vi ct thp c ko sau trong ng ghen, cn ch phng nga ct thp ny c th b xt st.

4.8. Mi cng tc lp t trong kt cu lp ghp hay ton khi(khng k nhng iu

b sung trong BVTC) u phi c tin hnh mt cch t m trc khi b-tng; cc kt qu kim tra v nghim thu phi c ghi vo bin bn i vi cc hng mc cng tc n du.

4.9. Trnh t cng ko ct thp trong kt cu phi tun theo ch dn ca n thit

k. Kt qu cng ko tng si hoc b si cng mt lc phi c ghi vo nht k

cng trnh. 4.10.Khi cng ko ct thp trong kt cu b-tng, phi m bo cc yu cu sau: a)Cng b-tng trong kt cu v v tr mi ni t khng c thp hn tr

s quy nh ca thit k tng ng vi mi cng on, cng b-tng c xc nh bng phng php khng ph hu mu hoc bng th nghim nn mu; trc khi cng ko ct thp, phi kim tra kch thc ca kt cu theo thit k v phi m bo khng c vy g, k h v nhng khuyt tt khc lm nh hng n cht lng ca b-tng;

b) Kt cu nn p phi ta ng v tr theo ch dn ca thit k, cn im ta gi dm phi m bo chuyn v t do;

c) u neo v kch phi c t ng tm trng vi si thp ko cng v gi nguyn v tr trong sut qu trnh cng ko;

d) Ct thp cng ko xong phi c ph lp bo v, hoc c b-tng chm ln, hoc c bao ph bng vt liu ngn cch theo ch dn ca thit k bo v ct thp khi b g trong sut qu trnh cng ko.

4.11.Khi cng trc ct thp trn b, cn phi: a) Trc ht chn la ct thp cng chu lc ng u: ko cng c nhm ct thp

hoc cc nhm thp n gi tr 20% ca lc cng kim tra, v gi trng thi ny; b) Theo di trng thi chu lc v gi nguyn v tr thit k ca ct thp, ca dy

no hoc ca cc thit b gi im un ca ct thp. c) m bo vic iu chnh li nhng si ct thp c lc cng thp hn lc cng tc

ng ban u, no cht li hoc cng ko li cc b ct thp .

14

d) Khng c gy ra mt mt ng sut trong ct thp to d ng lc vt qu tr s quy nh ca thit k (mt mt do chnh lch nhit ca ct thp cng ko v b-tng khi ninh kt); i vi kt cu theo thit k in hnh, quy nh khng qu 60MPaa (600kg/cm2).

4.12. Kt cu b-tng, khi c ni lc cng trc do ct thp truyn vo, phi m

bo c cng bn khng nh hn tr s quy nh ca thit k. Trong trng hp ny, cn tun theo nhng yu cu sau:

a)Kt cu phi c ta vo v tr theo d nh ca thit k sao cho c chuyn v t do; khng c cht ti ln kt cu ngoi d nh ca thit k, k c tr s phn lc do ti trng b tc ng;

b)Vic nn p ln kt cu phi c thc hin mt cch nhp nhng; trnh t nh tng tao si thp cng cao (CC) phi tun theo ch dn ca thit k;

c)Trc khi ct ct thp bng hi hn, phi lm sch mt ngoi thp cho n mt b t khng c vt b-tng hoc cht bn khc bm vo ; vng ct ct thp b nung nng (sau khi ct) cng phi c lm sch. Khng cho php ct ct thp bng in hn; nn ct ct thp bng ca.

4.13.Mt ngoi cn neo v u cc b thp chu lc cn bc b-tng c chiu dy

khng nh hn chiu dy tng bo h ca kt cu ch th. 4.14.Vic cng ko thanh thp CC bng phng php nhit in phi c tin

hnh theo yu cu cu thit k, ph thuc biu cng ngh vch ra trong BVTC. 4.15.Vic kim tra cht lng mi ni ct thp khng chu lc phi c thc hin

ph thuc chng loi thp v c ch dn trong n kt cu cng trnh. Phng php kim tra (ph hu hay khng ph hu mu) c quy nh trong

thit k. Theo phng php khng ph hu mu, phi kim tra 100% cc mi ni hn cho

chng loi thp u tin, 50% cho chng loi th hai v 15% cho chng loi th ba. Theo phng php ph hu mu, vic kim tra theo thit k quy nh vi s mu

th ph thuc chng loi mi ni cn kim tra. 4.16. Nghim thu cng tc ct thp, gim st cht lng, khi lng v phng

php kim tra ct thp, thc hin theo quy nh trong bng 4. Bng 4

Yu cu k thut i tng kim

tra Phng php

hoc cch thc kim tra

1. Thi gian bo qun si thp CC, ct thp v cp thp ni che ph kn hoc trong nh kho-khng qu 1 nm. m khng kh- khng c qu 75%.

100% ct thp CC

Dng my o m

2. sai lch cho php so vi thit k, tnh theo mm:

Kch thc bao ngoi ca sn ct

Tng sn

o bng thc

15

thp lin kt v li ct thp: i vi ct , dm, bn v vm, 10 i vi mng, 20 Khong cch gia cc thanh ct thp

ring r hoc cc hng ct thp vi nhau theo chiu cao:

nt nt

i vi kt cu c chiu dy trn 1m v kt cu mng, 20

nt nt

i vi dm, vm, bn, c chiu dy (theo mm)

Tng sn o bng thc

Trn 300l 10. nt nt T 100 n 300, 5 nt nt n 100, 3 nt nt Khong cch gia cc ct ai ca dm

v ct, gia cc lin kt ca sn ct thp, l 10.

nt nt

Khong cch gia cc ct thp phn b trong mi hng, 25.

nt nt

V tr cc ct ai so vi trc kt cu (hng ng, hng ngang hoc xin), l 15.

nt nt

3.Sai s cho php khi ch to, lp t v cng ko ct thp so vi tr s thit k:

Chuyn v dc tng h u mt thanh ct thp, l 0,5mm cho mi 10m di ca b thanh.

Tng thanh ct thp o kim tra theo mu

Cng ko t u neo cc si thp CC-khng thp hn tr s ni lc ko ca si.

Lm 6 mu kim tra trc khi thi cng.

Lp li vic kim tra ny khi dng n

10.000 neo, trong trng hp thay i khun c v sa

cha thit b cp gi neo

Lm th nghim ko t o kim

Kch thc u neo, 0,2mm nt o bng thc cp com pa

4.Sai s (theo mm) khi kim tra chiu di ca hai u thanh chu ko:

Theo nhm thanh, l 10. Theo th t, l 30.

Tng thanh ct thp

o bng thc trn b cng hoc trn gi

5.Sai s (theomm) v khong cch gia cc thp hoc thanh thp vi cc chi tit khc ca ct thp chu lc:

nt o bng thc trn b cng hoc trn gi

Khi c li tnh theo thit k nh hn

60mm, l 5. Tng b phn kt

cu nt

16

Khi c li tnh theo thit k ln hn 60mm, l 10.

nt nt

6.Sai s (theo mm) v v tr thit k ca neo trong b-tng khi cng ko ct thp v cp thp trn b:

mt u gn u dm, l 40

Tng ct thp nt

mt gia, gn u dm l 60. nt o bng thc cc mt khc, i vi cc neo cn

li, 200 (khi khong cch tnh nh nht gia cc neo l 100mm).

nt nt

7.Sai s cho php khi kim tra chiu di L ca thanh ct thp (khong cch gia mt trt trong ca neo v u neo) l 0,001, trong phm vi + 50; -40mm.

Tng kt cu neo o bng thc

8. knh ca mt ta (b cng trong phm vi t kch v neo, khng qu 1: 100

Mi thng kim tra mt ln, khi ko trn

b v khi ko sau trn khi b-tng

mi nt lin kt

o trc tip t trn b cng hoc trn gi

9. chnh xc ca im t kch khi

cng ko nhm ct thp tng ng vi lc tc dng ng u l 10mm

Tng im t kch o kim tra gc nghing v mt g gh theo mt phng

ta 10.Cng trc cp thp xon hoc bn

i, ko vt 10% tr s ni lc kim tra, duy tr trong khong 5 pht.

Tt c cp thp

o bng thc dt

11.Dung sai cho php (tnh theo %) v cc tr s cng ko ct thp bng kch(so vi ni lc kim tra):

Ring r i vi ct thp cp thp, thanh hoc si thp khi ko

Tng ct thp o lc bng my o tn s hoc my o ng tng t

Theo trnh t l 5 20% ct thp trong nhm

o kim tra bng my p k v dn

di Theo nhm l 10 Tng nhm nt Tng ct thp nt

Chung tt c i vi ct thp, cp

thp, thanh v si trong mt nhm, l 5. o bng thc dt

12.Sai s v tr s dn di so vi thit

k (theo %) Ring r i vi ct thp, cp thp,

thanh v si thp, l 15

Tng nhm

nt

Trong mt nhm ct thp, cp thp, thanh v si, 10.

Tng thanh ct thp nt

13. chnh xc khi o dn di nt o bng dng c c

17

n hi chu ko (theo mm) ca : Ct thp dc l 0,1

chnh xc tng ng

Ct thp ngang (ct ai) l 0,1 nt nt 14.Tr s (%) cho php ca tng cc

mt mt ng sut ko gy ra do ma st kch v phn ngm ca neo.

Vi neo kiu chn u c ng bc, l 5 (*)

Ch khi xc nh ni lc kim tra

o kim tra qua my p k v dn di bng my o tn s hoc my o ng

tng t Vi neo hnh cn, 10(*) nt nt 15.Thi hn cho php (tnh theo ngy

m(**) h ct thp trong rnh, khng c bo v chng g, nhng cha c phun p va bn trong (khi m khng kh ca mi trng bn ngoi nh hn 75%)

L 30, i vi thp si. Tt c cc ct thp Kim tra thi gian theo ng k (s nht k thi cng)

L 15, i vi cp thp. nt nt L 30, i vi thp thanh(to d ng

lc bng nhit ). nt nt

(*) - Tr s ny c th c xc nh qua th nghim. (**) - Cho php c thi hn cao hn quy nh ny ch trong trng hp p dng gii php c bit bo v ct thp tm thi khi b g. D c p dng gii php bo v ct thp tm thi, nhng i vi tt c ct thp chu lc h trong rnh khng c qu thi hn 3 thng. Tt c thi hn cho php c tnh tng ng m mi trng l 75%; nu m thc t ln hn, tt c thi hn cho php u phi rt ngn hn theo quan st hin trng. Ghi ch : 1. Cc ct thp dng si, cp v thanh nu c sai lch v tr s lc cng ko vt qu gi tr quy nh trong bng ny, u phi cng ko li hoc thay th. 2. Cho php li trong kt cu khng qu 5% s lng ct thp trong tng s, s ct thp ny hoc ko qu n di 20% ni lc lm vic, hoc ko cha n ng sut chu ca - si thp . 3. trit tiu dn n hi ca ct thp, tin hnh to ni lc trc bng 20% ni lc kim tra trong ct thp

18

CNG TC B TNG

4.17. Vic sn xut v vn chuyn b-tng phi tun theo quy nh ca Kt cu b-tng v b-tng ct thp ton khi-quy phm thi cng v nghim thu do Nh nc ban hnh v cc qui nh ca qui phm ny. Hn hp b-tng c sn xut trong my trn quay cng bc; cho php sn xut hn hp b-tng t nhuyn ln hn hoc bng 5cm bng my trn kiu trng lc, (o bng st t do).

Va xi mng- ct c sn xut trong my trn va. Cho php sn xut va xi mng-ct trong my trn quay cng bc lm b-tng.

4.18. Cht ph gia cho va c a vo my trn ng thi vi vic a nc

vo. Cht ph gia m c phi c ho sn cho long ra. Cc loi ph gia phi c ho trn sn trc khi vo my trn cc ct liu, theo ch dn ca hng ch to.

4.19. Thng cha, khi dng vn chuyn hn hp b-tng, cn phi c lm

sch v thau ra sau mi ln cha hn hp; vic lm sch v thau ra thng cha khng c chm lu qu 30 pht.

4.20. Vic b-tng phi thc hin theo quy nh ca BVTC. Hn hp b-tng phi c vo vn khun thnh tng lp ngang, khng c gin on theo hng di chuyn t mt pha cho tt c cc lp. Khi din tch mt ct ngang ca kt cu b-tng tri di trn 4m hoc tri rng trn 3m, cho php v m nn hn hp b-tng theo cc lp xin, hnh thnh cc on ngang di 1,5 - 2m ca cc lp chng ln nhau. Gc xin theo mt phng nm ngang ca cc lp chng ln nhau khng c vt qu 300, trc khi tin hnh m nn. Sau khi v ri u hn hp b-tng theo tng lp trn sut b mt, mi tin hnh vic m nn b-tng theo tng on.

4.21. Hn hp b-tng c th c cung cp bng my bm hoc my nn kh cho

mi hnh loi kt cu vi cng sut b-tng khng nh hn 6m3/gi, mc d c iu kin kh khn no v nhng ni mi phng tin c gii khng th qua li c.

4.22. Trc khi tin hnh m nn, tng lp hn hp b-tng phi c dn

u trn b mt ngang ca kt cu. Chiu cao tri ln cc b so vi cao chung ca mt phng hn hp b-tng, trc khi m nn, khng c qu 10cm. Cm dng cc loi m rung san u v nh bng cc lp hn hp b-tng nm trong vn khun. Cc lp hn hp b tng ch c tin hnh m nn sau khi dn tri v san u trn b mt .

4.23. Phn hn hp b-tng b mt mt trn dy chuyn v thit b b-tng vo

kt cu phi c tnh b cho . Cm vic dng nc b vo phn hn hp b tiu hao trong qu trnh b-tng.

4.24. Lp hn hp b-tng sau phi c trong thi gian lp b-tng ri

trc cha b ninh kt. Nu qu trnh b-tng b gin on vt qu thi gian bt u ninh kt ca lp hn hp b-tng trc, phi lm ngay vt ni thi cng. Lp b-tng vt ni ny phi t cng t nht l 1,2 MPa mi c tin hnh tip trn vt ni thi cng. thi gian cho php tip hn hp b-tng sau ln gin on c xc nh qua mu trong phng th nghim, ng thi ph thuc vo phng php lm sch lp mng xi mng trn mt vt ni thi cng.

19

V tr ca vt ni thi cng phi c quy nh theo BVTC. Nu khng c quy nh ring trong thit k th b dy ca lp b-tng tip sau khi t vt n thi cng phi t t nht bng 25cm. Cc vt ni thi cng khng c t nhng on c nc chy qua, v nhng on ngp nc c cht n mn.

4.25. Hn hp b-tng cho mi lp ri hoc mi ln hon thin bng my

rung, phi c m nn k sao cho c chc li mi ngng, khi vng bt xi mng ni ln trn mt v ch tip gip vi vn khun.

4.26. Cc loi thanh rung, x rung hoc my m bn ch c th dng thch hp vi

kt cu b-tng; chiu dy mi lp hn hp b-tng c v m nn khng c qu 25cm.

i vi kt cu BTCT, vic to rung ng mt ngoi c th p dng khi m nn lp b-tng mt trn v mt ngn cch.

4.27. Mt thong ca phn b-tng mi xong (k c khi tm ngng ) phi

c bo m khi b mt nc, phi che y kn trnh nc ma ri thng vo . Vic bo v mt thong ca b-tng mi xong phi c duy tr ngay trong sut

thi gian cho n khi b-tng t cng khng nh hn 70% cng thit k . 4.28. Trong qu trnh hn hp b-tng phi m bo nguyn vn trng thi ca

hnh dng kt cu, vn khun v dn gio . Khi pht hin c bin dng hoc c chuyn dch cc b kt cu vn khun, gio hoc ch lin kt, phi c gii php chnh sa ngay lp tc hoc trong trng hp cp bch, phi nh ch ngay vic thi cng khu vc xy ra.

4.29. Nhng yu cu k thut thi cng b-tng, khi lng v cch thc kim tra

nghim thu cng tc b-tng, c quy nh theo bng 5.

Bng 5

Yu cu k thut i tng kim tra

Phng php hoc cch thc

kim tra 1. Ti v tr , hn hp b-tng phi

m bo st theo thit k v khng sai khc qu 15%, cn ch s cng khng sai lch qu 10% so vi thit k.

Khng t hn 2 ln cho mt hn hp, hoc c 2gi kim tra 1 ln khi gp thi tit thay i, m thay i v khi thnh phn ct liu c bin ng.

Kim tra theo TCVN 4453 - 1995 v cn

c vo s nht k thi cng .

2. Nhit ca ct liu hn hp b-tng khng c sai khc qu 20C so vi tr s tnh ton khi lm th nghim (nc v thnh phn hn hp khi cho vo my trn, hn hp b-tng hoc va khi

C 4 gi kim tra 1 ln vo ma ng; hoc 2 ln kim tra cho mt ca lm hn hp b-tng trong

Da vo nht k thi cng, dng nhit k

o.

20

ra khi my, hn hp b-tng hoc va ti v tr .

iu kin nhit khng kh thun tin.

3. Chiu dy mi lp hn hp b-tng khng c vt qu tr s sau:

Trong sut qu trnh b-tng.

o v quan st

40cm - khi m cht trn bn rung, rung hoc h rung n hi.

nt nt

25cm - khi cch m cht nh trn v kt cu c hnh dng phc tp, c ct thp b tr dy c.

nt nt

5 n 10 cm - khi b tr u my m dc theo chiu di kt cu, my c gn cht v t cng vo thnh bn kt cu.

nt nt

40cm - khi m cht bng my m di cm tay.

nt nt

25 cm - khi dng my m bn hoc my rung trn x i vi kt cu b-tng khng c ct thp v c mt lp ct thp.

nt nt

12cm - i vi kt cu c 2 lp ct thp

nt nt

4. Phn nh khi lng b-tng cho ton b kt cu nh sau:

Din tch mi khi - khng qu 50m2.

Cho tng kt cu o v da vo nht k thi cng

Chiu cao khi - khng qu 2m B tr mi ni thi cng - nhng ch

c tht hp.

nt nt

5.Chiu cao (theo m) ri t do ca hn hp b-tng khng c ln hn tr s:

nt nt

2 - khi vo kt cu b-tng c ct thp.

nt o v quan st

1 - khi cu kin BTCT c sn. nt nt 6 - khi vo kt cu b-tng khng c ct thp, vi iu kin m bo ng nht ca b-tng v tnh nguyn vn ca vn khun.

nt

nt

5. THI CNG NN V MNG

5.1. Cng tc thi cng nn v mng cn theo cc yu cu ca Tiu chun hin hnh,

cc qui nh ca qui phm ny v n thit k k thut, BVTC.

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5.2. Trong trng hp thi cng cc dng mng khc nhau cn phi tun theo cc mc trong phn 5 ca qui phm ny, cho php tham kho cc ti liu c lin quan khc nh: a) s thi cng v v tr mng v b mng, cu to cc v h thng vng vy ngn nc km theo cc ch dn v sai s theo mt bng v chiu cao; b) bng tin tng hp, s nht k ng cc, cc ng, v cc vn thp, nht k khoan v b tng vo l cc khoan nhi; c) cc kt qu th ng cc ng (dng ba ng hoc ba rung); d) cc kt qu nn tnh cc ng, cc ng hoc t nn mng (nu h s thi cng yu cu).

H CC V CC NG

5.3 Cc c ng h bng ba m bo su ngm thit k n chi nhng khng c nh hn 0,2 cm cho mt nht p, cn cc ng c h xung bng ba rung vi nng sut h rung giai on cui khng nh hn 5 cm/pht. Nu yu cu trn khng c kh nng t c, cn p dng phng php xi mi cc hoc t cc vo l khoan mi h cc n chi tnh ton, i vi cc ng p dng phng php o t pha di mi cc trc hoc dng ba rung loi ln hn. Cho php o t ct pha di mi cc trc t 1-2m, vi iu kin khi c p lc nc tha trong lng cc, tc l c ct nc trong lng cc cao trn 4-5m so vi cao trnh mt nc hoc cao trnh mch ngm. 5.4. su khoan mi cc bng 0,9 chiu su h cc trong t, cn ng knh l khoan mi bng 0,9 ng knh cc trn hoc 0,8 ng cho cc vung cng nh cca gic, v c iu chnh theo kt qu h th cc. 5.5. Kt cu cc h xuyn qua tng dy l loi t cng, c thc hin bng cch dng mi khoan dn hng. Cho php ng cc trc tip qua lp st do mm hoc t st m khng c thnh phn t cng. 5.6. Sau khi h xong cc ng, cn ly ht t mn y lng cc, lm sch, nghim thu y cc (k c vic m rng mi cc) v t lng ct thp trong trng hp cn thit, sau b-tng nhi vo lng cc. Sau mi ln buc phi dng thi cng, cng vic b-tng nhi c th tip tc thc hin nu khong thi gian dng khng lm mt linh ng ca hn hp . Trong trng hp ngc li ch cho php tip tc cng vic khi c gii php m bo cht lng lin kt tt mt tip gip gia phn b tng mi v phn trc . 5.7. Vic y hn hp b tng trong lng cc ng BTCT trong phm vi c du hiu thay i nhit do tc ng ca mi trng xung quanh (nc, khng kh, t) phi thc hin theo yu cu c bit c ch dn trong BVTC (la chn thnh phn hn hp, cch nhi b-tng, lm sch mt trong lng cc,...) cao trnh di phm vi mt on bng mt ln ng knh cc nhng khng nh hn 1m, m bo an ton cho cc c th hn ch s xut hin vt nt trong khi b-tng nhi.

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5.8. Vic kim tra v nghim thu cht lng cng tc ng cc v cc ng qua cc a tng khc nhau phi tun theo yu cu k thut ghi trong bng 6.

Bng 6

Yu cu k thut i tng kim tra

Phng php kim

tra 1. Sai lch cho php v mt bng tim cc v cc ng so vi thit k ti v tr y b hoc i cc: a) i vi cc vung, cc tam gic v cc c kch thc khng ln hn 0,6 m (tnh theo cnh cc vung, cnh nh cc tam gic, hoc ng knh cc trn) b mng ti ch hoc trn i cc, tnh theo tr s cnh hoc ng knh (m) nh sau: Khi cc b tr mt hng theo mt chnh cu:

- theo hng dc cu, khng vt qu 0,2 ca tr s

Tng cc o bng thc

- theo hng ngang cu, khng vt qu 0,3 ca tr s

nt nt

Khi cc b tr hai hng hoc nhiu hn theo mt chnh cu:

- i vi hng cc ngoi cng, dc cu, khng vt qu 0,2 ca tr s

nt nt

- i vi hng cc gia, dc cu, khng vt qu 0,3 ca tr s

nt nt

- theo phng ngang cu, khng vt qu 0,4 nt nt b) i vi cc vung, cc tam gac v cc trn c kch thc khng ln hn 0,6 m sai lch cho php l 5 cm (khng ph thuc vo s lng cc) b mng kiu lp ghp hoc trn mt nn bt buc phi dng cc thit b nh hng (lng khung ct thp, khung dn hng, cn cu).

c) i vi cc ng ng knh ln hn 0,6 m n 3 m, ng xin, tnh theo tr s ng knh (m) nh sau:

Khng s dng thit b nh hng: - i vi cc n v cc b tr mt hng theo mt chnh cu, khng vt qu 0,1 ca tr s.

Tng cc ng o bng thc

- i vi cc b tr 2 hng hoc nhiu hn, khng vt qu 0,15 ca tr s.

nt nt

Khi c khung dn hng (khung nh v) - nu trn cn, khng vt qu 5 cm

Cho tng cc ng

o bng my thu bnh

- nu trn nc, su nc l H(m) khng vt qu 0,03H -

nt nt

2. v dch cho php ca tim h khung dn

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hng so vi v tr tim cao trnh mt khung nh sau: - nu trn cn, l 2,5 cm. nt nt - nu trn nc su nc H(m), l 0,015H. nt nt 3. sai lch ( gim nh) ca chiu su h cc v cc ng so vi tr s thit k (khi h cc vo t trn 4m, c xt n xi cc b):

a) Cc di n 10m (vi iu kin tnh kh nng chu theo t nn) l 25cm

Tng cc

Quan st o bng thc gn

trn thn cc Cc di trn 10m, l 50cm. nt nt b) Cc ng vi mi chiu di l 25 cm nt nt Ghi ch: 1. Sai s cho php ca cc cc (cc v cc ng) so vi n thit k, trong mt bng, c tnh ti mng v c tnh ngay trn cc tr khng c b ( b-tng ti ch) c coi nh ti cao trnh b mng hoc i cc. Cc tr s cho php v sai lch v tr so vi n thit k theo mt bng ca h cc nu trn bao gm c tr s chuyn v mt y b cc hoc i cc do c sai lch ca cc theo phng ng hoc do c thay i xin cc. Sai s cho php v thay i gc tang theo phng thng ng (so vi tr s thit k) ca cc cc xin khng c vt qu 200:1 khi b tr theo 1 hng v 100:1 khi b tr t hai hng tr ln. 2. i vi cc loi mng v cc tr c b hoc i cc ch to sn, c lin kt vo cc cc nh cc u ct thp dc th ra v lp y b-tng ti ch, sai lch cho php v v tr cc theo mt bng so vi thit k mt y b hoc i cc khng c ln hn 5cm.

Trong trng hp b v i cc ch to sn, khi lp ghp vo h cc v cc ng, phi dng ni ghp kiu lin hp hn thp vi thp v bu lng lin kt, sai lch cho php trong trng hp ny c qui nh theo thit k. 3. S lng cc b sai lch khng vt qu 25% tng s cc i vi cc mng v tr c mt hng cc v 40%, i vi mng cc c hai hoc nhiu hng cc. 4. Khi s cc thc t b sai lch so vi thit k vt qu tr s gii hn cho php, vic chp thun kh nng dng li h cc ny phi c c quan t vn thit k mng hoc tr xem xt gii quyt.

THI CNG CC KHOAN NHI

5.9. Cng tc thi cng cc khoan nhi cn theo cc yu cu ca qui phm ny v tiu chun ngnh v Cc khoan nhi-Qui trnh thi cng v nghim thu.

5.10. Cho php s dng p lc ca ct nc hoc dung dch va st gi thnh vch

l khoan thi cng cc khoan nhi; nu v tr l khoan cch cc ngi nh hoc cng trnh hin c nh hn 40m, cn la chn gii php thi cng thch hp m bo an ton n nh cho cc cng trnh ln cn .

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Trng hp to l cho cc khoan khng dng ng (ng thp, ng BTCT) gi vch l m dng gu ngom t (c bit i vi l cc c nc) cn phi hon chnh mt trong l cc khoan n ng knh thit k bng thit b ng doa hnh tr trn (ng chun lm c).

5.11. gi khng cho lng ct thp ca cc b y ln hoc dch chuyn trong qu trnh rt b tng vo l, cng nh trong mi trng hp b tr lng ct thp khng ht ton b chiu cao ca cc, cn phi c kt cu gng gi c nh lng thp theo ng v tr thit k.

5.12. Trng hp gp l khoan kh trong lp ct, l khoan c ng vch (ng thp

hoc BTCT) cng nh l khoan khng c ng vch do xuyn qua a tng st v st ti v tr cao hn mc nc ngm nhng khng xut hin lp ct hoc ct y l, cho php b-tng lng cc khng dng ng dn m rt t do cao ri khng qu 6m.

Trng hp gp l khoan y nc, thi cng b-tng trong lng cc theo phng php rt ng theo chiu thng ng, c qui nh trong Qui trnh thi cng b-tng di nc bng phng php va dng.

5.13. Cng tc kim tra, nghim thu cht lng thi cng cc khoan nhi phi tun

theo yu cu k thut ghi trong bng 7. Bng 7

Sai s cho php i tng

Kim tra Phng php kim

tra 1. sai lch cho php v v tr mt bng nh v v trc xin (tga) ca cc khoan so vi thit k: (tnh theo tr s d - ng knh cc):

Khi b tr mt hng cc theo mt chnh cu: 0,04 d; 1:200 - trng hp thi cng trn nc.

Tng cc o bng my thu bnh, ng di v thc dy.

0,02 d; 1:200 - trng hp trn cn. Tng cc o bng my thu bnh, ng di v thc dy.

Khi b tr hai hoc nhiu hng cc theo mt chnh cu:

0,1 d; 1:100 - trng hp thi cng trn nc.

nt nt

0,05 d; 1:100 - trng hp thi cng trn cn.

nt nt

2. Sai s cho php (tnh theo cm) v kch thc thc t ca l khoan v kch thc m rng bu y cc so vi thit k:

25 - theo chiu su l khoan ( cao trnh)

Tng l khoan o theo ch dn ca thit k mng cc.

5 - theo ng knh l. nt nt

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10 - theo chiu su ca on hnh tr m rng bu.

Tng on m rng

nt

10 - theo ng knh m rng. nt nt 5 - theo chiu cao on hnh tr m rng.

nt nt

3. Sai s cho php (tnh theo cm) v v tr t lng ct thp trong lng cc khoan so vi thit k:

1 - theo v tr t ct thp dc vi nhau trn ton chu vi ca lng.

Tng lng ct thp

o bng thc cun thp v thc dt.

5 - theo chiu di thanh thp. nt nt 2 - theo c ly cc bc ai xon c. nt nt 10 - theo khong cch cc vng ai cng mt lng thp.

nt nt

10 - theo khong cch cc con k to lp bo v ct thp.

nt nt

1 - theo chiu cao con k nt nt 2 - theo ng knh ca lng thp ti v tr t vng ai cng.

nt nt

4. Sai s cho php v ch tiu va b-tng vi ln kim hnh chp 16-10cm, b-tng trong nc vo lng cc theo phng php rt ng theo chiu thng ng:

2 cm - theo tr s st. Theo TCVN Theo TCVN 2 % - theo tch nc. nt nt 5. Sai s cho php v ch tiu b tng lm cc khoan:

Khng c vi phm v tnh lin tc trn ton chiu di cc

2 cc cho mt cu

Kim tra bng thit b c chng v quan st

+ 20; - 5% cng b-tng nt Kim tra 6 mu t li khoan qua cc.

CH TO V H GING CHM

5.14. i vi mi v tr c th, cn la chn cc gii php thi cng ch to ging

chm ph hp vi kh nng k thut ca n v v m bo hiu qu kinh t cao, nh: ch to ngay trn v tr t mng (dn mt bng thi cng trc, to mt bng trn o p, lm sn cu cng tc c nh)hoc lm bn cnh v tr xy dng mng (lp cng a ring, lm trn h ni hoc sn cng tc); km theo cc gii php thi cng h ging chm vo su lng t : dng tc ng ca trng lng bn thn (thm ph ti xp-kch p nu cn; kt hp xi thnh bn; dng o va st ...) hoc dng dn ba rung h.

5.15. Trong qu trnh h ging n cao thit k, cn phi c gii php phng

nga kh nng ging b nghing lch (dng kt cu hng dn, o t ng u theo mt bng y ging, cht ti cn bng trn ging trong trng hp dng ph ti cn bng trn

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ging trong trng hp dng ph ti xp hoc kch p...) hoc b kt trong t (dng lp o va st, xi thu lc hoc kh nn, cht ti...).

5.16. phng nga kh nng ct tri xy ra lp y ging, phi m bo sao

cho chn ging lun ngp su vo t t 0,5 n 1m, cn mc nc trong ging khng c thp hn mc nc bn ngoi. Nu gp trng hp ging b treo hoc khi cn y xa cc m ci nm kt di chn ging, ch cho php tin hnh cc thao tc trong iu kin lun c p lc nc d tha trn mt y ging bng cch y nc vo sao cho mc nc bn trong cao hn mt nc bn ngoi xung quanh ging t 4 n 5m.

5.17. Kim tra nghim thu cht lng ch to v h ging chm phi tun theo cc

yu cu k thut ghi trong bng 8.

Bng 8

Sai s cho php i tng kim tra

Phng php kim tra

1. sai lch cho php (tnh theo %) v kch thc mt ct ging so vi thit k:

0,5 - theo ng knh ngoi, nhng khng qu 10 cm.

Tng ging o bng thc

0,5 - theo chiu di v chiu rng ca ging, nhng khng qu 12 cm.

nt nt

1 - theo ng cho ca ging. nt nt 0,5 - theo ng bn knh trn quanh ging, nhng khng qu 6 cm.

nt nt

2. sai lch cho php (tnh theo cm) v chiu dy thnh ging so vi thit k:

3 - nu l b tng nt nt 1 - nu l b tng ct thp nt nt 3. sai lch cho php v v tr h ging so vi thit k:

Theo chuyn v ngang mt trn ca ging l ... 0,01 ca su h ging

nt o bng my kinh v v thc

Theo phng thng ng l ... 1% ca nghing.

Tng ging o bng qu di v thc

Theo su h ging l ... 30 cm. nt nt

THI CNG MNG NNG

5.18. Khng cho php c s gin on gia hon thnh thi cng h o vi xy dng kt cu mng. Trong trng hp phi gin on cng vic trn, cn c gii php m bo c tnh t nhin ca t nn ti . Lp y h o gn n cao thit k (khong 5 - 10 cm) cn c sa dn sch mt trc khi thi cng mng.

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5.19. Trc khi thi cng mng phi hon thnh vic a nc mt v nc ngm ra khi h o (o rnh hoc m ng thot nc ngm, h mc nc ngm...)cn c la chn ph hp vi iu kin ti ch v c s chp thun ca t chc t vn thit k. Trong trng hp ny, cn c gii php khng cho t bn ng di y h o v khng lm ph hu c tnh t nhin ca t nn ti . 5.20. Trc khi thi cng mng cng trnh cn phi lp bin bn nghim thu h o vi s tham gia ca Ch cng trnh, T vn gim st v Nh thu; trong trng hp c bit phi c s tham gia ca c quan T vn thit k v n v o c.

Hi ng nghim thu cn cn c vo h s thit k mng: V tr, kch thc, cao y mng, hin trng ca nn v c tnh ca t nn, cng nh kh nng t mng theo thit k hoc thay i cao trnh mng. Vic tin hnh kim tra nn t mng khng c lm tn hi c tnh t nhin ca t ti ; khi cn thit, ngoi vic ly mu lm th nghim trong phng, c th thm d hoc p th trn nn t. Nu Hi ng nghim thu thy c trng ca t nn theo thc t khc vi thit k th cn phi xem xt n BVTC; vic tip tc thi cng phi c c quan T vn thit k v Ch cng trnh quyt nh sau khi i chiu v tnh ton li. 5.21. Cc kt cu c sn dng thi cng mng nng phi c t trn mt lp m ct, dm hoc ct xi mng c dy khng nh hn 5 cm (i vi t nn st) v c m cht san phng mt cch cn thn. Trong trng hp nn c ch lm cc b th phi p b t cng loi m bo mt nn phng v cht. 5.22. Vic kim tra nghim thu cht lng thi cng phi tun theo cc yu cu k thut ghi trong bng 9.

Bng 9

Sai s cho php i tng kim tra

Phng php kim tra

Sai s cho php (tnh theo cm) v kch thc thc t v v tr b tng mng - b mng ti ch (hoc lp ghp) so vi n thit k:

5 ( 2 ) - Theo kch thc mt bng Tng mng v b o bng my kinh v v thc

di + 2; - 5 ( + 1; - 0,5 ) - Theo chiu dy lp bo v.

Tng mng v b o bng my kinh v v thc

di 2 ( 1 ) - Theo cao trnh nh (mp) mng hoc b.

nt nt

2,5 (1) theo v tr mt bng soo vi tim cu nt nt Ghi ch: Tr s ghi trong du ngoc trn bng tng ng vi mng v b lp ghp.

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Trong qu trnh thi cng mng nng, cn kim tra: Phn t phi dn ht trong h o, cu trc ca t nn khng cho php b xo trn

hay b hu hoi; Cu trc ca t khng cho php b hu hoi trong thi gian ht dn, chun b mt

nn v lp t cc khi mng c sn; Gi cho t trong h o khi b ngp nc d lm lp trn mt nn b nho v xi

mn; c trng ca t nn thc c so vi thit k; Tnh y ca cc gii php p dng bo v t nn khi b bin tnh trong thi

gian h o h l ra v cho n khi hon thnh xy mng; su v kch thc thc t ca mng, cng nh v cu to v cht lng vt liu

lm mng, so vi thit k.

6. THI CNG CU CNG B TNG V B TNG CT THP.

6.1. Khi xy dng cu cng BT v BTCT phi tun theo cc iu qui nh ca tiu

chun Nh nc v Kt cu b-tng v b-tng ct thp- Quy phm thi cng v nghim thu, tiu chun ngnh v Qui trnh thi cng v nghim thu cu b-tng d ng lc, ngoi ra, phi tun theo cc yu cu k thut nu trong Qui phm ny.

6.2. Trong giai on thi cng lp hng, kch y, lao ko, ch ni kt cu nhp dm,

nh thu xy dng phi c trch nhim lp trc cc bc cng ngh thi cng trin khai thc hin.

6.3. Vic lp t cc kt cu c sn ch c php bt u sau khi kim tra

bng my v cao v v tr mt bng ca m tr, mng, v cc thit b ph tm thi cng, cng nh cc cng vic o c nh v xc nh v tr lp t kt cu theo thit k, kt qu kim tra c ghi vo bin bn.

Trc khi lp kt cu nhp trn cc tr m phi xp t sn cc gi theo ng tim cu.

Qu trnh lp t kt cu, t khi ghp ni cu kin cho n khi xong ton b, phi thng xuyn theo di v kim tra bng my. Ni dung kim tra gm: chnh xc v v tr cc on hoc khi lp, trng khp mt tip gip, cc chi tit k m, cc khoang trng, cc rnh ng lun v cc chi tit kt cu ti mt ni ghp v mi lin kt.

6.4. Sau mi khoang ch to xong (hoc mi khi lp) ca kt cu nhp, u phi

dng trc c kim tra v tr khoang lp theo mt bng v mt ct dc. Khi dng trc c kim tra, phi theo di ln ca tr trong qu trnh thi cng, cn trong trng hp cn thit, phi xt tnh n nh hng ca bin dng tc thi do c gia nhit khng u ln kt cu.

Trong qu trnh lao ko dc (hoc sng ngang) kt cu nhp trn h con ln phi tin hnh kim tra thng xuyn bng trc c v v tr tim nhp cu v cc tr (k c tr tm). tin hnh kim tra trng thi ng sut trong kt cu khi c ch nh ca thit k.

6.5. Khi thi cng lp t kt cu cu phi p ng cc yu cu c bn sau:

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a) Cn cu thi cng t ti v tr c xc nh trong BVTC v b tr ngoi thc a. Cm vic ngm gi my cu vo kt cu ang lp rp, cm vic neo gi v tho h khi lp nhng v tr cha c xem xt trong thit k TCXD;

b) Vic h kt cu nhp xung sn o, vic tho d sn o, cho kt cu nhp ta vo con ln v vic iu chnh tr s phn lc gi ta hoc tr s ng sut u phi tun theo cc yu cu k thut nu trong h s thi cng;

c)Vic lp t khi th ln t cu kin phng dng phin (bn) c thc hin bng cch dng gi dn hng hoc kt cu khc tng t, m bo chnh xc v hnh dng khi cng nh mt ct dc - ngang khi th, m bo ng dy ca lp tip gip cc cu kin;

d) Ch tin hnh tho b hoc tng cng cc b phn lin kt khi khng xut hin ni lc ph trong cc b phn .

6.6. Tt c cc cu kin v cc ph kin trc khi lp t thnh khi ln phi c kim tra k. Nu pht hin c sai st, Hi ng nghim thu bn bc c gii php khc phc.

Trn cc cu kin dn tri ra lp rp cn phi ghi r mt ngoi: danh s v trng lng m hng, im trng tm ca cu kin v tr mc cu cng nh ng tim kim tra v tr t mc o c.

6.7. B mt tip gip ca cu kin nhp cu BTCT, trc khi chuyn vo v tr lp

hoc trc khi ghp thnh khi th, cn phi lm sch bng phng php phun ct hoc bng bn chi. Khng c dng cc dng c no p hoc bm vo mt tip gip.

Vic lm sch b mt tip gip ca cu kin phi c thc hin k lng v c nghim thu cn thn.

6.8. Ti cc b mt tip gip (mt cu) ca cc t ng cng BTCT c sn nu b

st v do b c st vi mc cu, trc khi lp t, phi c sa cha v trt va b-tng lin mt nh ban u; khng c dng dng c c khot vo thn cng hoc khng c k t cho t cng b un vng.

6.9. Khi s dng cc phng tin chuyn ch ta v ghm cc cu kin cn phi

ch khng pht sinh bin dng d trong kt cu; mt u cc khi lp ghp ni theo chiu di kt cu v cc mt chng thm phi c bo v khi b st v.

Vic vn chuyn cc loi dm kh ln, cc cu kin c sn ca kt cu nhp v m tr, cng nh cc cu kin BTDL, phi c thc hin theo ng cc yu cu c bit nu trong BVTC hoc cc yu cu k thut qui nh trong cc tiu chun ca Nh nc v ngnh GTVT; nu vn chuyn trn sng, phi tun theo ch dn ca c quan qun l ng sng.

Vic xp t cc cu kin ln phng tin vn chuyn phi m bo neo chng chc chn, trnh c tc ng ca lc gi, lc xung kch v lc ly tm. Trong trng hp cn thit phi bo m xp t hng trong khun kh nht nh c th xoay chuyn d dng khi phng tin i vo ng cong; trng hp cu kin di chuyn ch trn xe moc, mt u ca cu kin phi trn mt ta sao cho d di ng; nu l phng tin ch ni, phi m bo n nh v thng bng khi di chuyn.

6.10. Cc cu kin phi xp vo kho cn p ng cc yu cu v bo qun nh sau:

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- Khng c qung nm hng ln cc phng tin vn chuyn; - Gi gn cc cu kin khng b h hng do dy buc hoc cc chi tit kp gi khc. - Khng c t cc khi lp BTCT ln cc con k. Cc loi gi cu cao su v cc b phn khe co dn mt cu phi c bo v

trnh tc ng ca nh sng mt tri, phi cch cc thit b sy t nht l 1 m, trnh mi tc ng ca du la v cc ho cht khc gy ph hu cao su.

LP T CC MI NI THI CNG CU

6.11. Cc ct thp ch v tm lt phi c hn ghp li sau khi ghm gi cc cu kin c sn ng v tr thit k. Trnh t thao tc hn phi thc hin theo ch dn ca thit k, theo cc yu cu ca Tiu chun ngnh Cu thp v kt cu thp- quy trnh thi cng v nghim thu v bo m gim nh nht tr s ng sut ph pht sinh do hn. Khi chnh sa cc u ni cn ch loi tr cc vt nt gy thp v khng lm vo tng bo h b-tng. Cng tc b-tng mi ni ch c thc hin sau khi nghim thu mi hn v t ct thp, cng nh khc phc cc sai st pht sinh. Ti nhng mi ni m ct thp ch khng s dng hn hoc ti cc chi tit m lt, ch c thc hin b-tng sau khi hon thnh cng vic chnh sa mi ni v c nh cc cu kin c sn vo ng v tr ni ghp theo thit k. Cc mi ni dc gia cc phin dm (bn dm) v cc mi ni ngang ca nhp dm gin n c thc hin b-tng sau khi h dm vo gi cu chnh thc. Trnh t b-tng ti cc mi ni trn nhp dm lin tc hoc lin tc nhit c tin hnh theo n BVTC ring. 6.12. Ti cc mi ni trn mt cu, trc khi b-tng hoc va, phi c ra sch v gi m t. Hn hp b-tng (va) c vo mi ni mt cch lin tc v c m nn cn thn. Mt l ra ngoi ca b-tng (va) phi c m nn tht bng phng ngang u vi kt cu cn c ni ghp v trnh khi b bc hi nc trong thi gian bo dng (ph lp gi m, ri vt liu ngn cch nh nng..) 6.13. Hn hp cht keo dng vo mi ni phi c lm th nghim trc trong phng th nghim kim tra cht lng ca thnh phn vt liu. Khi cn thit, phi kim tra Moduyn n hi v h s Poatsng ca keo. D vi hp cht keo tng ng theo yu cu ca thit k nh vy, nhng vn phi kim tra thm sc chu ct ca mi ni keo qua mu th nghim (mu keo hnh lp phng). i vi cc mi ni b-tng dng keo dn, phi chn thnh phn cu t thch hp vi iu kin ngoi tri thay i, khi ng dn khng phi dng cch sy nng kao dn trong mi ni. 6.14. Khi thi cng mi ni, keo c ph u ln hai mt ca kt cu b-tng cn ni ghp. Khng c l keo chy tri trn mt ng ca kt cu vto dy lp ph keo thch hp, c mi ni keo kht cht khi nn bng trc p n gin ng vin chu vi. Mi ni keo c nn p trc tip sau khi bi keo ln b mt b-tng cn ni ghp trong mt thi gian ngn tu thuc c tnh cng ngh v bm dnh ca keo. tin hnh nn p mi ni keo, nn p dng mt s ct thp trung gian to ng sut hoc

31

dng thit b chuyn dng, to nn lc nn p u trn ton mt ct ca mi ni keo t tr s ng sut 0,05- 0,2 Mpa (0,5- 2 kgl/cm2). Trong trng hp cn phi iu chnh mt ct dc v v tr ca kt cu lp t trong mt bng, c s tho thun ca c quan thit k, cho php b sung khng qu 15% khi lng keo lm lp chm iu chnh kt cu, nhng chiu dy ln nht mi ni khng qu 5mm.

Trong trng hp dng keo ni ghp cc cu kin ca m tr theo chiu cao, cho php bi keo ln mt mt ca mi ni v keo c nn p ngay trong qu trnh lp t dn cc khi lp ln cao.

6.15. Trong qu trnh v sau khi kt thc thi cng lp ghp kt cu (trc khi tho d vn khun, cht ti tm thi hoc kt thc vic cht ti) cn phi kim tra cng bn ca mi ni v i chiu vi thit k theo tng giai on thi cng. Mi trng hp thay i thnh phn hp cht, vt liu lm mi ni v thnh phn keo, cn phi ghi chp y vo s nht k thi cng.

6.16. Yu cu k thut thc hin cc mi ni thi cng cu, khi lng v

phng php hoc cch thc kim tra nghim thu trong qu trnh thi cng, c qui nh theo bng 10.

Bng 10

Yu cu k thut i tng kim tra

Phng php hoc cch thc

kim tra 1. sai lch cho php v v tr tng

quan cc cu kin BTCT c sn, lin kt bng mi ni va b-tng:

a) Sai lch mp ngoi ca cc cu kin ni gn nhau: 5mm

Cc lin kt o bng thc dt, my ton c hoc

th di. b) Nghing lch ca ng tim tr ng

c chiu cao H (m) so vi v tr thit k mt ct nh tr:

Khi H < 4,5m, l 10mm

Cc tr ng o kim tra bng my ton c hoc

th di. H = 4,5m 15m, l 15

nt nt

H > 15m, l 0,001 H nhng khng ln hn 35mm

nt nt

c) Sai lch vcao trnh nh tr, ct ng, tr khung l 10mm

Cc kt cu o my thu bnh

32

d) Sai s v chiu dy khe ni gia cc cu kin c sn:

Vi khe ni hp, dy t 20 n 30mm l 10mm.

Vi khe ni rng, dy t 70mm tr ln, l 20mm

Cc khe ni o bng thc dt

2. Dung sai cho php v cc ch tiu hn hp b-tng v va lm mi ni:

nt nt

a) T l nc: xi mng vi hn hp b-tng l 0,35-0,5 vi va, khng ln hn 0,45

100%

Theo cc tiu chun t TCVN 3105-1993 n TCVN

3111-1993 b) st

vi hn hp b-tng l 4-5 cm vi va, khng ln hn 8 cm

nt

nt

3. Cng cho php ca b-tng v va khi lm mi ni;

a) Trong thi gian nn p trong khun dn khi lin kt tm thi v tho d vn khun, khng nh hn 15 Mpa (150 kgl/cm2).

b) Trc khi tho d ti trng thi cng hoc ti trng khai thc, cng phi t tng ng tr s qui nh ca thit k i vi tng giai on thi cng

4. Cc ch tiu cho php v lin kt cc cu kin c sn bng keo:

a) i vi mi ni dn keo cht kht c chiu dy trung bnh (chn khng t hn 4 im o theo chu vi mi ni) khng c ln hn 3mm. Chiu dy ln nht ca mi ni keo nhng im o cc b theo chu vi, cho php khng ln hn 5mm.

Tng mi ni Quan st, kim tra bng thc cp hoc thc dt chnh xc.

b) Mduyn n hi ca keo 1500 MPa (15000 kgl/cm2).

Tng m phi trn keo

Quan st, kim tra mu 2x2x8 cm khi tng ng sut 0,2-0,4 MPa/s

c) H s Potsng 0,25 nt nt 5. lu ho ca keo (tnh theo gi):

Theo cng ngh (thi gian bi keo ln b mt cn dn), khng t hn 1 gi.

Tng t 20 pht mt ln

Quan st, kim tra s sut hin dng

chy t qung ca keo khi nhng a thu tinh hay inh

vo . Theo tnh ho cng (thi gian cu kin

c th dnh cht vo nhau khi p) khng t hn 4 gi

Tng t qua mi

gi

Quan st, kim tra dnh bm ca keo

qua gng tay

33

PHUN P V LP Y TRONG NG RNH.

6.17. Vic phun p va xi mng ct vo ng kn v lp y vo rnh h phi do i th chuyn nghip thc hin.

Vic phun p vo ng kn v lp vo rnh h c tin hnh sau khi kt cu lp t xong v a trc tip cc b thp cng cao hoc ton b ct thp d ng lc vo trong kt cu. Nu khong thi gian t lc ko xong ct thp n khi phun lp va vo ng rnh vt qu thi hn quy nh ghi trong mc 15 bng 4 th phi c gii php tm thi bo v ct thp khi b g (dng np hoc ng chp kn ln u neo, lm l thot khi m y di ca u neo, nh k a lung kh nng kh vo rnh, dng cht c ch tm thi to mng ph ln ct thp trong ng kn, hoc c th dng xi mng-cadein bc tm thi ln ct thp t trong rnh h..)

6.18. Dung dch va phun p phi c ch bin sn v nho trn trn my chuyn

dng cho nhuyn bm vo kt cu. Khng c trn va phun p bng phng php th cng.

6.19. Trc khi bt u phun p va vo ng khng qu mt ngy, phi bm y

nc vo xc nh kn ca ng. Nhng ch r r pht hin thy v mp vin ng phi c bt kn ngay sau khi y nc ra khi ng. ng thi dng ng chp lm sn y kht ln neo, nu cu to neo khng c sn cc nt y l bm ny.

Trong trng hp ng khng c kn n mc nh hng n cht lng phun p, Hi ng nghim thu phi a ra gii php khc phc, c s tham gia ca i din c quan t vn Thit k.

6.20. Dung dch va c tin hnh phun p vo trong ng, sau khi bm y

nc vo ng ny. Khi cc v tr neo ct thp d ng lc t cc cao khc nhau, vic bm y va phi bt u t cc neo nm pha di trc.

Phun p va vo ng c tin hnh lin tc. Trong trng hp hnh thnh Nt bt ng ng, dng nc bm ra lng ng v phun p va mi thay th. Sau khi ng kn no va cn nt cht l bm va ninh kt tt.

i vi nhng ng c on cong xin hai u, tin hnh nn p va qua ng ni gn vo c 2 u neo. Trong qu trnh phun p va vo ng, va c bm t mt pha u neo sang u neo i din l hon tt vic phun p.

6.21. Vic phun p va vo nhng ng t thng ng theo chiu cao ca thn m

tr c thc hin theo tng tng cao 20-25m mt on, tng ng vi tng on ct thp to d ng lc t theo chiu cao ca thn m tr nh thit k quy nh.

Phn trn ca cc tng t ng (khng k tng trn cng) trong thn m tr u c lp ng ni va thot ra khi bm vo lng ng, va lp tip on ng cho tng trn v bm va tip vo.

T vic bt u phun p va vo ng tng di cng ln n tng trn cng theo chiu cao ca thn m tr, ch tin hnh trong thi gian khng qu 5 gi. Ring phn va trong ng ca tng trn cng phi c nn p cht.

34

Trc khi lp y va (b-tng) vo rnh h, hai bn vch ca rnh v cc ct thp cng d ng lc phi c lm sch v thi kh kh. Va (b-tng) lp y vo rnh phi c m nn cn thn. Trng hp ct thp d ng lc c xp thnh b v t vo mt s hng rnh h, vic lp va phi tun theo ch dn ca BVTC. Trn b mt b-tng lp rnh c ph lp chng thm nc gm mt s mng ngn p li, hoc lp ph bao ti, bo dng m 2-3 ln trong ngy v duy tr trong vng 2 tun l.

6.22. Khi phun p vo ng kn v lp y trong rnh h, phi tin hnh kim tra

thng xuyn cht lng cung cp va (b-tng) v qu trnh p () va (b-tng),kt qu kim tra phi ghi vo s nht k thi cng.

6.23. Nhng yu cu k thut khi thi cng phun p v lp y trong ng rnh, khi

lng cng vic kim tra nghim thu cng nh phng php v cch thc kim tra, c qui nh theo bng 11.

Bng 11

Yu cu k thut i tng kim

tra Phng php

hoc cch thc kim tra

1. Cc ch tiu c trng ca va bm a) Tnh lu ng: ngay sau khi va sn

xut ra, l 40 2 giy. Va sn xut ra sau 60 pht, l 80 5

Khi c s thay i kp th iu kin vt liu v cng

ngh bm

Theo TCVN, kim tra qua mu 10x10x10cm

b) co ngt (gim th tch) khng qu 2%

nt Theo TCVN

c) Cng t c sau 7 ngy khng nh hn 20 MPa (200 kgl/cm2) v sau 28 ngy, khng nh hn 30 MPa (300 kgl/cm2)

Kim tra trn mu nn th 10x10x10cm

(theo TCVN) 2. Vt liu va bm: a) Xi mng poclng (lm b-tng cu

cng) mc 400 hoc cao hn. Khi phi trn vt

liu Kim tra theo TCVN

b) Cht ph gia ho do nt nt V kt qu trong phng th nghim

3. Cng ngh phun p: a) p lc lm vic ca my bm va

0,5- 1 MPa (5-10 kgl/cm2) Trong qu trnh

bm Qua my p lc k

b) tc lp y va vo ng rnh khng ln qu 3m/pht

nt Theo di tng gi

c) nn p va trong ng 0,6 0,05 MPa (6 0,5 kgl/cm2)

Trong qu trnh bm

Kim tra bng p lc k

d) thi gian nn p, 5 2 pht nt Quan st trn ng h e) ng knh l u vi bm khng

nh hn 14mm Trc khi bt u

thi cng o bng thc cp

35

g) ng knh l u neo hoc kt cu tip nhn va bm vo, khng nh hn 16mm.

nt nt

4. Vt liu b-tng (va) dng lp y rnh h:

Xi mng poclng mc 500 hoc cao hn

Khi la chn thnh phn b-tng hoc va

Theo TCVN

5. tch nc ca b-tng (va) trong 24 gi khng ln hn 2% th tch

Khi la chn thnh phn b-tng hoc va

Theo TCVN

Ghi ch:

Trng hp ng rnh bng kim loi hoc bng nha tng hp, vic phun p v lp y va c t l N/X ln hn 0,4 c tin hnh bt k ma kh hu trong nm.

NHNG C IM THI CNG KT CU B-TNG TON KHI

6.24. Khi la chn loi hnh vn khun pha tun theo cc yu cu quinh ca Tiu chun ngnh Qui trnh thit k cc cng trnh v thit b ph tr thi cng cu.

6.25. Khi la chn gia cng vn khun dng b tng v b tng ct thp lm m tr cu, cn phi xem xt nhng im sau:

- Tnh bin dng ca vn khun v b t (i vi kt cu d ng lc) di tc dng ca ni lc nn p;

- Nhng u gc vung v gc nhn ca kt cu b-tng phi gia cng vn khun vut thnh gc trn bn knh 20mm, hoc phi vt mp theo kch thc khng nh hn 10x10mm (nu trong bn v thit k khng c ch dn khc);

- dc mt bn vn khun ca khi nguyn th l 1 : 20.

6.26. Cng tc nghim thu vn khun nh hnh, ch to sn trong xng, phi tun theo cc yu cu ca nh my ch to.

6.27. Mi cng tc chun b b-tng vo vn khun u phi c ghi nhn vo bin bn cng tc.

6.28. B mt vn khun tip xc vi b-tng phi c ph lp chng dnh trc khi . Cht chng dnh c ph kn mt lp mng ln b mt vn khun c lm sch cn thn.

B mt vn khun sau khi c ph lp chng dnh cn phi gi khng dy bn, nc ma v nh nng mt tri.

36

Khng cho php lm dy cht chng dnh vo ct thp v cc chi tit k m.

Khng cho php s dng cht chng dnh trong c thnh phn gy tc ng xu cho b-tng.

Khng cho php s dng cht hn tp du m thi cng nghip lm cht chng dnh.

6.29. Cc yu cu k thut cn phi p ng trong gia cng ch to v lp t vn khun, khi lng cng tc kim tra nghim thu cng nh cch thc kim tra, c qui nh theo bng 12. Kt cu vn khun v cc bo m theo ng kch thc ca cc b phn cu (c tnh n vng thi cng) nh trong bn v thit k.

Bng 12

Yu cu k thut i tng kim tra

Cch thc kim tra

1. Sai s cho php v v tr v kch thc lp t vn khun tun theo Tiu chn Vit Nam v Tiu chun ngnh v kt cu b-tng v b-tng ct thp ton khi.

Mi kt cu vn khun, kim tra trong qu trnh

lp.

o bng my kinh v, i chiu mc cao c v o bng thc cun

2. Sai s cho php v khong cch: Gia cc gi ta vn khun ca kt cu chu

un v gia cc im lin kt ca kt cu b t thng ng so vi kch thc thit k, l 25mm- theo 1m chiu di. Khng ln hn 75mm- theo ton di.

Tng khong

cch

o bng thc

cun

Vnh phng trn mt phng thng ng hoc mt nghing ca vn khun theo thit k, gia cc ng giao ct, l:

5mm- theo 1m chiu cao. 20mm- theo ton chiu cao ca mng. 10mm- theo ton chiu cao n 5m ca thn

tr v ct.

Tng mt phng o bng thc dt v dy di

3. Sai lch cho php v v tr tim vn khun so vi thit k l:

15mm- i vi mng 8mm- i vi thn tr v mng kiu ct

kt cu thp.

Tng ng tim

o bng thc

cun

4. Sai lch ca khung t kch vi ng tim ca kch theo ng thng ng: khng cho

Tng ng tim im kch hoc

o bng thc v th di

37

php c sai lch. b t 5. chnh cao ln nht cho php ca

dm gnh khung t kch, l 10mm Cao mi dm

gnh o bng my

thu bnh 6. cn cho php ca vn khun trt

vi mi cnh bn l + 4 v -2 tnh theo 1 m chiu cao.

Tng vn khun trt

o bng th di

7. cn ngc: khng cho php nt nt 8. Khong cch cho php gia kch v

khung t (khng k trng hp khong cch gia cc khung t tu ) l 10mm

Theo thit k o bng thc cun

9. Sai lch cho php v ng tim: ca kch so vi ng tim kt cu l 2mm.

Tng ng tim nt

ca vn khun c hon v hoc xp t li, so vi ng tim ca cng trnh, l 10mm

nt nt

10. Sai lch cho php v khong cch gia cc mt trong vn khun so vi kch thc thit k, l 5mm

Tng vn khun o trn vn khun hoc sn

phm kt cu u tin

11. g gh cc b cho php ca vn khun l 3mm.

nt Quan st bn ngoi v kim tra bng thc 2m.

6.30. Hn hp b-tng khi vo trong thn tr kiu lp ghp theo tng tng phi c ri u theo chu vi ca thn tr v m nn k trn ton b din tch theo tng tng , nht l gn cc v tr ni thng ng v cc khe lm ca khi.

Vt ni thi cng gia cc tng ring r phi nm cch mt trn ca tng khi lp bao quanh v phi di l 20-30cm, nhng khng c ln hn mt na chiu cao ca khi lp bao quanh.

Qu trnh b-tng cc khi lp phi ghm gi cht gia cc lin kt cng vi nhau; nhng mp ni ghp no b h cn c trt kn li.

6.31. Ti phn thn tr m tip xc thng xuyn vi mc nc thay i cao-thp trong ngy, hn hp b-tng kt cu thn tr hoc b-tng trong lng ct ng, trong phm vi ny, phi c thm cht ph gia chng n mn do mi trng; st ca hn hp phi t trong khong 2-4cm theo phng php o hnh chp ct.

Trc khi hn hp b-tng vo trong lng ct ng theo phng php di nc, b mt b-tng c trc phi lm sch mn t v lp xp ph bn trn.

6.32. Khi thi cng kt cu nhp theo phng php c hng, vic b-tng tng

on hng phi c tin hnh lin tc v khng c c vt ni thi cng. on b-tng tip sau ch c tin hnh sau khi phn b-tng trc t cng theo ch dn ca thit k.

6.33. Nhng yu cu k thut phi thc hin khi tin hnh b-tng kt cu ton

khi, khi lng v cch thc kim tra, theo qui nh ca bng 13.

38

Bng 13

Yu cu k thut i tng kim

tra Cch thc kim tra

1. Cng b-tng cho php t: ca lp bt y trong lng mng ging hoc

trong h mng trc khi tin hnh ht nc, khng nh hn 2,5 MPa (25 kgl/cm2)

Trc khi bt u ht nc ra

Theo TCVN v TCN

ca phn kt cu thi im b ngp nc, khng nh hn 2,5 MPa (25 kgl/cm2)

Trc khi b ngp nc

nt

ca phn nm trong lng ct ng, theo phng php trong nc, trc khi lm sch mn v b-tng xp trn mt, khng nh hn 2,5 MPa (25kgl/cm2)

Trc khi bt u b-tng tip

o ti ch v ghi vo s nht k

cng trnh

2. Nhit cho php: ca kh quyn khi b-tng vo lng kt cu thn tr ton khi lp ghp, khng thp hn 150C.

C 4 gi mt ln o ti ch

XY LP MNG V M TR.

6.34. Cc khi lp m tr phi c t ng cao trnh v theo ng ng th di bng cc tm nm iu chnh. Mi tng khi lp thn m tr khng cao qu 5m, mt trn ca tng di ng thi l nn ca tng trn phi c o c cao trnh v i chiu v sai s cho php. Khi thc hin thi cng cc mi ni ghp cc khi lp, phi ch trt kn cc khe l h c th gy mt va.

Va b-tng xi mng ct dng trt kn phi c st trong khong 6-9cm.

6.35.Mt ngoi ca cc mi ni ghp khi lp theo vin bao quanh phi c trt kn bng va xi mng-ct kh t cng 30 MPa (300 kgl/cm2) v bo qun trnh b nt. Mi ni theo vin bao quanh phi c lm phng mn, cht, dnh kt tt vi b-tng. Khng dng keo dn lm mi ni theo vin bao quanh ny.

6.36. Khi thi cng kt cu c sn ca m tr cu dng ct (nh cu vt cao),

phn ca thn ct phi c gi cht tm thi nh b g dng chuyn dng bng thp hoc kt cu dn hng.

ng lt ct dng nm chn gi phi c a vo n mt na chiu su ca bo m sao cho c th b-tng lin khi cho ct chn v rt nm chn ra. Trong mi trng hp phi c bin php khng cho nc chy vo ng lt ct v mng.

6.37. Trc khi xp t cc khi lp thn m tr v mng, phi gi gn cc khi

ny khng b bn. 6.38. Cc yu cu k thut cn phi tun th khi thi cng mng v m tr, khi

lng cng tc v cch thc kim tra, c qui nh theo bng 14.

39

Bng 14

Yu cu k thut i tng kim

tra Cch thc kim

tra 1. lch dch cho php:

cc mp bin ca khi lp c sn lin k lm thn m tr l 5mm.

Tng hai khi lin k

o bng thc

2. Sai s cho php: v chiu dy khe ni t thn m tr,

to thnh t cc mp ca khi lp, l 5mm.

La chn ch nghi

ng

nt

v ng tim cc khi lp mng v m tr, lin kt bng cc khe ni t

l 5mm- theo chiu cao l 10mm theo cc kch thc khc cn

li

La chn ch nghi ng

o bng thc

3. dy cho php ca mi ni thn m tr bng cc khi lp, vi mi ni l keo dn, tun theo im 4-5 ca bng 9.

Xem im 4-5 bng 9

Xem im 4-5 bng 9

4. Sai lch cho php ca cc ng tim to thnh theo chiu cao kt cu m tr:

Khi dng mi ni keo dn, tnh theo n v chiu cao H, l 1/250.

Tng thn m tr Dng my kinh v v cao c quan

st

Khi dng mi ni t, khng ln hn 20mm

nt o bng thc

5. Hn hp b-tng dng vo lng m tr:

thnh phn xi mng khng nhiu qu 350 kg/m3.

Tng tr m Kim tra t mu b-tng chn.

T l N/X khng qu 0,5. nt nt Chiu dy ca mi lp ri khng ln hn

300mm Tng tr m o bng thc

1. Sai s cho php v v tr tim kt cu: khi thi cng so vi ng tim m tr

theo mt bng o c trn ton mng i vi tim cc, cc ng, ct theo mt

bng, cao trnh mt di i cc, l 30mm

Tu chn ch nghi ng

nt

i vi tim tr , ct tr , cao trnh mt nh, l 5mm.

Tu chn ch nghi ng

o bng thc

7. Sai s cho php v cao trnh thit k nh cc cc (cc ng, cc ng, cc khoan) so vi mt di ca i cc, l 50mm

nt nt

8. Khe h nh nht cho php: gia mt bn kt cu cc, ct tr vi mt bn ca l cha sn trn i cc, l 30mm.

nt nt

THI CNG XY LP CNG

40

6.39. Cc khi c sn lm mng ng cng c lp t trc tip trn nn ngay sau khi nghim thu h mng, nn t mng cng c thi cng theo ng dc dc thit k v vng xy dng qui nh.

Cc khi lp c t theo tng on mng theo hng t ca ra cng ln dn n ca vo cng. Mi khi hoc mi hng khi lp trong phm vi mt on mng phi t ph hp vi thit k v thng hng theo mt mt phng ca mng lm chun. Cc khi lp sau khi lm sch mt ngoi, phi c t theo ng v tr thit k trn mt lp va xi mng ri mt; khng cho php trt va b sung vo di khi c lp t, cng nh vic x dch khi c sau khi va ninh kt. chnh cao khi lp trong mt hng khng c vt qu 10mm.

Mt dc ch ghp ni phn h o su nht ca mng tng u vi mt nn ca mng thn cng phi c lp y bng ct- dm hoc hn hp ct- xi mng, m cht theo tng lp v ri va xi mng ln.

6.40. Khe ni ng ca mi hng khi c phi c lp y va ct- xi mng, cnh ngoi khe ni ng cng trt kn mt vi cc khi tip gip nhau.

Khi va khe ni mt ngoi ninh kt th khng c trt thm vo mch ni. 6.41. Cng kiu ng thp tn ln sng c sp xp v lp t ti v tr thit k

sau khi nghim thu phn t nn lm mng cng. 6.42. Khi thi cng cng, cn phi thc hin cc yu cu sau: a) u cng ca ra c thi cng trc khi lp t cc on thn cng. b) Khi lp t cc t cng trn phi m bo lp b-tng m di cc t cng

t dc thit k v c gc vt sao cho tip xc cht kht vi b mt ng cng pha di theo sut chiu di thn cng.

c) Lp t cc t cng vung gc hoc t cng ta trn mt , phi dng va c st 6-8 cm lm lp m.

d) Khi t cc on cng bng thp tn ln sng phi dng b g nh hnh bao gi pha di khng thp hn 1/3 mt ct ngang ng, hoc phi to mt nn san rt bng phng sau nm t ct hai bn thnh ng rt cn thn ng thi m nn k n cao trn 1/3 mt ct ngang ng.

e) Vic lp rp cc ng tn ln sng phi m bo sao cho gia m bulng, ai c, vng m vi bn tn thp khng c dnh ht t.

6.43. Vic kim tra nghim thu lp t cng phi c tin hnh trc khi lp t c ghi bin bn.

6.44. Cc ch tiu k thut cn thc hin trong thi cng xy dng cng, khi lng

v cch thc kim tra c qui nh theo bng 15.

Bng 15

41

Yu cu k thut i tng kim tra

Cch thc kim tra

1. Sai s cho php v v tr thi cng lp t cc cu kin ca cng:

Bc chnh cc khi c lm mng trong cc hng khng cao qu 10mm.

Tng mp chnh khi c

Dng thc o

Chiu di v chiu rng ca cc on mng, l + 2 v -1cm.

Tng on mng Dng thc o

x dch tng i ca cc cu kin b-tng v BTCT lin k, l 10mm.

Tng cu kin nt

Khe h gia cc on mng v cc t cng (theo ch s thit k), l 5mm.

Tng khe h nt

ng tim dc cng theo mt bng v mt ct dc (vi iu kin khng c on ng nc), l 30mm

Tng cng Dng my thu bnh v da vo

bnh . 2. Cng bn cho php ca lp va ct

xi mng: Khi xy cc khi lp mng, dng cp va

theo quy nh ca thit k nhng khng nh hn 20 MPa.

T l N/X khng ln hn 0,65

Tng th tch va mt mng

Theo TCVN

3. st cho php ca va ct - xi mng: Dng cho san nn di y ca hng khi

lp mng di cng v dng cho khe ni ngang, l 6-8cm, theo phng php hnh nn ct.

nt

nt

Nh trn cho khe ni ng l 11-13cm. nt nt Nh trn, cho khe ni ph ngoi, l 2-3cm nt nt

Ghi ch:

Khe h gia cc t cng v cc on mng cng phi trong mt mt phng.

LP T KT CU NHP

6.45. Trc khi thi cng lp t kt cu nhp, h thng cn cu nng chuyn cc loi a n cng trng u phi qua kim nh v nh gi cht lng. Hot ng ca cc my cu trn nn t p ch c php tin hnh sau khi t ti y m nn cht ph hp vi yu cu ca BVTC.

42

6.46. Cc loi cu kiu cnh hng v kiu khung cng t trn ng ray, khi vn hnh, phi c n v chuyn ngnh qun l ng st cho php. ng ray my cu di chuyn phi ph hp tiu chun lp t hin hnh.

6.47. Khi nng, h v di chuyn kt cu nhp (dm) phi: - m bo sao cho qu trnh nng v h theo phng thng ng; khng c dng

ti ng thi no cng kt cu; - m bo khe h gia mt di ca kt cu lp t vi nh ray hoc mt t

khng nh hn 0,2m; - m bo sao cho cn vi ch hot ng trong phm vi nh trc ca n

BVTC.

6.48. Trc khi tin hnh lp t kt cu nhp v cc dm ring r bng my cu kiu hng chy trn ng ray qua cc tr , phi:

a) Kim tra trc nn ng p cho my qua li, tnh trng ng, cng bn v n nh vn c ca kt cu cn lp t, v quan st phm vi gii hn bi cc kin trc xung quanh my cu nng ti c th a lt vo;

b) m bo sao cho vic qua li ca my cu trn cc ng ray k tip nhau m khng b st mt in p trong li in cung cp.

6.49. Trnh t di chuyn my cu cc loi trn cng trng lp t kt cu nhp phi c xc nh trc trong h s BVTC.

6.50. Trong trng hp cng mt lc dng hai cn cu vi tin hnh mt cng

vic, cn thc hin mt cch nghim ngt cc qui nh ca BVTC, di s ch o thng nht ca ngi chu trch nhim v an ton lao ng trn cng trng. Trong h s BVTC phi xc nh r trnh t vn hnh (nng cu, thay i chiu cao, gc quay) cho mi cn cu vi, s cp treo v ng di chuyn c xt n ti trng trn my cu v sc nng ti.

6.51. Cc yu cu k thut cn tun th trong thi cng lp t kt cu nhp, khi v

cch thc kim tra theo qui nh trong bng 16.

Bng 16

Yu cu k thut i tng kim tra

Cch thc kim tra

1. Tim dc theo mt bng ca kt cu nhp (hoc dm) ng st so vi ng tim ca mng o c, l 10mm.

Mi phin dm v kt cu nhp

o bng my kinh v da vo mng tam gic

c

2. Nh trn, nhng kt cu nhp (hoc dm) ng b, l 0,0005 L (L- chiu di nhp)

Mi phin dm v kt cu nhp

o bng my kinh v da vo

43

nhng khng ln hn 50mm. mng tam gic c

3. Nh trn, nhng kt cu nhp bng g, l 20mm.

nt nt

4. ng tim dm thi cng lp t trn kt cu nhp l 15mm.

nt nt

VIC NNG V H KT CU NHP.

6.52. Vic nng v h kt cu nhp bng h thng kch, bng cc loi my nng y hoc h bng cc hp hnh tr trn, c p dng trong iu kin khng th dng my cu mt cch thun li c. Khi nng kt cu nhp phi bo m t th lun n nh v ti trng phn b trn mi my nng lun ng u trn im ta. Khi nng (h) kt cu nhp bng h thng kch phi kim tra n nh ca kt cu trong trng hp chu tc ng ng thi ca ti trng ngang do lc gi v s gia tng tng h ca im ta, gia tng ny c tnh bng 0,01 tr s khong cch gia im ta. i vi cc im ta nhp dm BTCT, phi gi gn sao cho phn b-tng trn mt tr khi b h hng.

6.53. Qu trnh nng (h) kt cu nhp trn h thng kch thu lc, cho php:

- nghing lch ca kch khng vt qu 0,005 tr s chiu rng b k;

- Hnh trnh t do ca pit-tng (khng t nc hm) khng qu 15mm;

- Nng (h) kt cu nhp ng thi khng qu 2 im gn lin nhau;

- chnh cao cc gi ta nng (h) kt cu nhp theo hng dc v hng ngang khng ln hn 0,005 tr s khong cch cc gi ta khi dng kch nng v khng ln hn 0,001- khi dng pa-lng xch.

6.54. Khi phi h kt cu nhp t cao ln hn hoc bng 2m, nu khng th p dng h thng my cu c th dng cc hp ct hnh tr trn l li th. Trong trng hp , phi dng cc gii php bo m tnh n nh ca hp ct khi xy ra ti trng gi ngang cng nh khi dm b nghing lch.

Kt cu nhp h trn cc hp ct phi thc hin mt cch ln lt v t t, sao cho u ny ca kt cu khng c chnh cao vt hn u kia 0,005 tr s chiu di nhp. Cho php h ng thi kt cu nhp dm thp u trn cc hp ct khi c s theo di kim tra bngf my o c ti mi im h kt cu nhp sao cho chnh cao nt gi ta ny so vi gi ta kia khng vt qu 5cm.

THI CNG LP HNG KT CU NHP

44

6.55. Khi thi cng lp hng, na hng hoc lp hng cn bng cc kt cu nhp, phi tun theo cc yu cu sau:

a) Trc khi lp hng kt cu phi tin hnh phc tra t m vic ngm gi cc khi c lm i trng (neo) hoc lin kt cc cm khi neo, phi xc nh v tr lp hng theo mt bng v mt ct dc, nhng cu to lm mc (du), cch thc nh hng v lin kt chnh xc v tr cc khi lp theo h khng gian phi c qui nh trong n BVTC v c ch dn k thut sn xut khi c.

b) Cc khi lp hoc cc cu kin lp phi c t vo kt cu theo ng trnh t v tun th nghim ngt cc ch dn trong BVTC.

c) Nghim cm di chuyn cc my thit b lp hng, cc kt cu v vt liu, cng nh bt c khi th no khc cha c xt tnh trong thit k;

d) Trong qu trnh thi cng lp phi c m bo c h thng kim tra ng b v v tr khng gian mi cu kin c v kt cu; h thng kim tra v cc thng s kim tra ng b phi c quy nh trong BVTC.

e) Cn phi loi tr mi kh nng va p vo kt cu lp t trong khi thi cng hng.

6.56. Ch cho php kt cu lp t hng c ta trn hai tr tm (theo s lin tc) khi c cc my thit b c bit kim tra thng xuyn tr s phn lc c hai tr ta theo ch dn ca thit k, c s gim st ca tc gi n v s kim tra thng xuyn ca K s trng T vn gim st.

6.57. Cc b phn gi cu ca kt cu nhp lin tc sau khi c t ng vo v tr thit k, phi tin hnh tho d cc khi neo i trng. Vic d b cc khi ny phi tun theo ch dn BVTC. Cu to gi cu v neo gi cc khi phi c xt tnh n kh nng tin hnh chnh sa v tr gi ca kt cu nhp cho ng v tr trn mt bng v mt ct dc.

a cc thit b neo gi cc khi phi theo ng trnh t qui nh ca n BVTC.

6.58. Trc khi b-tng khi neo, phi thc hin lin kt vng chc cc on hng vo khi b-tng neo, loi tr mi kh nng phn b-tng trc b h hng do nhit bin i tng ln hoc do cc bin dng khc ca phn kt cu ghp ni hng.

6.59. Vic cng ko cc thanh b ct thp trong qu trnh ghp ni theo chiu di kt cu nhp cn phi thc hin c trnh t theo ch dn ca BVTC. Trong cc kt cu c dng keo dn ghp ni, cc ct thp chu cng ko d ng lc phi c b sung cho sau khi keo ng dn.

6.60. Khi to d ng lc cng hoc nn p kt cu bng cc ct thp cng cao, ngoi vic kim tra ni lc v ng sut ko trong ct thp, cn phi kim tra vng ca

45

kt cu, chuyn v ca cc gi ta v cc bin dng trong b-tng, theo yu cu ca bn thit k.

6.61. Thi cng ghp ni cc khi theo chiu di kt cu nhp bng keo dn phi t chc sao cho khong thi gian t khi bi keo n khi nn p mi ni keo t ngn nht (ph thuc cng ngh hoc kh nng bm dnh khi s dng mi ni keo).

Vic nn p nhanh mi ni keo y lng keo tha ra ngoi v vic t cht keo ni phi thc hin ng u trn ton mt ct ni. Ni lc nn p ph thuc c ca keo v kch thc b rng ca b mt dn keo. Kt thc vic nn p mt ni keo, tt c ct thp t trong rnh ca kt cu phi c lm sch cc vt c dnh keo.

Khi bi keo ln b mt cn ni ca khi lp lin k, phi bo m khong cch gia cc mt u khng nh hn 0,3m; cc khi lp phi c c nh chc chn khi b x dch gn li nhau trong qu trnh gia cng mt ni keo.

6.62. Cc yu cu k thut cn phi thc hin khi thi cng lp hng kt cu nhp BTCT c sn, khi lng v cch thc kim tra, c qui nh theo bng 17.

Bng 17

Yu cu k thut i tng kim tra

Cch thc kim tra

1. sai lch cho php theo mt ct dc v mt bng u mt cc khi lp hng, ghp ni theo chiu di bng keo dn, l 50mm, so vi v tr thit k.

Tng kt cu nhp

Quan st bng my cao c, kinh v v thc o di

2. Tr s cho php nn p nhanh mi ni keo khi lp hng khng nh hn 0,2 Mpa (2kgl/cm2).

Cho mi mt ni o bng p lc k v lc cng trong ct thp

3. lch cho php theo mt ct dc v mt bng v v tr ca cc khi lp hng, ghp ni theo chiu di bng hn hp va b-tng, l 20mm so vi v tr thit k.

Tng kt cu nhp

Quan st bng my cao c, kinh v v thc o di

LP T CC KT CU NHP TRN CU TM

6.63. Vic lp t t hp kt cu nhp theo chiu di trn h cu tm di chuyn phi c thc hin mt cch chnh xc ph thuc cc cng c v thit b a ra phc v thi cng.

46

6.64. Vic t hp ng s hnh hc theo chiu di kt cu nhp trn cc dm di chuyn phi c o c kim tra trc theo ch dn ca BVTC v v tr khng gian ca ng ray dng di chuyn my thi cng. Mt ct dc nh ray phi tng thch vi ng vng n hi ca dm do chu ti trng ca khi lp v phi kt hp xem xt n cng ngh ch to cc khi lp c lm sn trong cng xng.

6.65. Vic vn hnh thit b lp dm c thc hin thng qua b tr tho d dm

cu tm, bo m c th di chuyn dm theo hng thng ng xui chiu hoc ngc chiu.

6.66. Khng cho php s dng my thi cng nng cu cc khi lp khc cha

c xt tnh trong thit k. 6.67. Mi phn on kt cu nhp a vo lp t phi c kim tra k lng v

v tr v phi nh v lin kt chc chn khi dn hng u tin. Vic ghp ni cc on khi c bng hp cht keo dn phi tun theo cc ch dn v cng ngh ta khe ni, m bo thun tin v an ton cho vic a keo vo khe.

Khi nn p cc on khi c c ghp ni bng keo phi t ng u trn ton b mt ni v theo ng thi hn, khng vt qu qui nh k thut s dng hp cht keo cho n khi bt u ng cng. Kt thc vic nn p mi ni keo, tt c rnh t ct thp cng cao phi lm sch trn ton chiu di rnh khi b dnh keo.

6.68. Mi ni hp long ca cc phn on lp kt cu nhp c thc hin bng

b-tng ti ch. B-tng khe ni c xc nh tu theo cu to ca khe v ch dn ca thit k.

6.69. Cc yu cu k thut phi thc hin khi thi cng lp t kt cu nhp dm

BTCT trn cc dm di chuyn, khi lng v cch thc kim tra c qui nh theo bng 18.

Bng 18

Yu cu k thut i tng kim tra

Cch thc kim tra

1. sai lch cho php v ng tim ca thit b lp dm v ng chy ca my cu so ci v tr thit k, l:

30mm, theo ng tim ca my lp dm 2mm, theo mt bng tim ray 2mm, theo mt bng nh ray nhng

chnh cao v nh ray trn cng mt ct bt k khng ln hn 1mm.

Trc khi lp t mi nhp

Quan st o bng my cao c, my

kinh v

2. Khe h cho php thi cng mi ni hp long:

Khng nh hn 600mm, i vi khe ni gia khi dn hng vi khi lin kt u tin, cng nh vi cc khi lin kt trc

Trong qu trnh lp t tng phn

o bng thc

47

bng keo dn. on.

Khng nh hn 400mm i vi khe h c tri u neo ca cc khi lp t sn

nt nt

Khng nh hn chiu da ca kch v 400mm, trong trng hp phi t kch vo khe ni cng ko ct thp cng cao.

nt

nt

LAO KO DC V SNG NGANG CC NHP CU

6.70. Vic ko v sng nhp cu phi c tin hnh di s ch huy trc tip ca

k s trng hoc i trng cng trnh. Nhng ngi hiu bit cc quy tc thi cng thch hp v cc quy nh v an ton k thut mi c php tham gia cng vic ko v sng nhp cu.

6.71. Lao ko nhp cu cn c thc hin bng cc thit b y, vic di chuyn kt cu nhp phi m bo u n vi tc cho php bng cch lp t kp thi cc tm m lm t vt liu d trt ln, nhm trnh lao mnh dm v chch hng i. Trong qu trnh lao ko cc nhp cu lin tc phi kim tra cc phn lc thc c ca tr v cc bin dng trong kt cu, ph hp cc hng dn ca BVTC. Trn nhp cu v c bit mi dn, khng c t nhng thit b v vt liu ngoi d tnh ca BVTC. 6.72. Khi lao ko nhp cu ti nhng ni c dc dc hay c cong ng th mt dc trt trn mi gi ta cn song song vi mt phng y dm trn cc gi gi . Trong BVTC cn c tr b trc thit b hm hoc cn cn thit.

6.73. Trong qu trnh lao ko, phi b tr sn thit b c bit theo di hng i ca kt cu nhp m bo chun xc v tr thit k tim cu theo mt bng.

6.74. kim tra vic sng ngang nhp cu, cc ng ln phi c nh du

bng sn bn vng vi 0,001 tr s khong cch gia cc ng ln.

6.75. Trong qu trnh ko v sng nhp cu, phi kim sot c vic di chuyn dm trn cc tr cu bng cch dng thit b m bo t ngt hot ng khi cn thit.

Trong thi gian lao ko (bng con ln ) nhp cu phi lp t h thng in m t i ch huy n cc v tr iu khin ln trn cng trng.

6.76. Kt cu ca gio cc phn on kt cu nhp t trn ng dn phi iu chnh c cao trnh v phi m bo khng b ln qu tr s cho php khi chu tc ng ca trng lng cc phn on v ca my cu.

6.77. Kch thc ca b phn y trt phi c t dc theo mt pha cng

hng vi kch hot ng v d sa cha b phn trt ny.

48

6.78.Khi lao ko kt cu m trong rnh dc ct thp khng c phun p va

hoc c phun p nhng cng va t nh hn 20 Mpa (200kg/cm2 ) th phi xt tnh thm cho kt cu ny trng hp c ct thp chu lc nhng khng c lin kt vi b-tng.

6.79