Trng i hc xy dng n tt nghip

Khoa Xy dng DD&CN kho 2011 -2014

Phn IIIThi cng(45%)

*** Gio vin hng dn: th.s pHM TIN TI Sinh vin thc hin : L TIN HNGNhim v thit k:*. Lp bin php k thut thi cng phn ngm K thut thi cng+ thi cng cc ( cc p)

+ thi cng t h mng

+ thi cng mng

T chc thi cng

+ thit k tin thi cng phn mng

+ thit k tng mt bng thi cng phn mng

+ lp bin php an ton lao ngChng i:

c im thi cng cng trnhi.tng quan v cng trnh

+ Tn cng trnh: k tc x i hc rng hm mt

+ a im: Trng Thi Hon Kim TP H Ni

+ K tc x trng i hc Rng Hm Mt ta lc trn ng Trng Thi qun Hon Kim thnh ph H Ni. Vi din tch khu t 5788 m2, mt chnh ca cng trnh quay ra hng ng chnh to nn v p tuyn ph, thun tin cho vic i li v hp l trong qu trnh thi cng cng trnh. Cng trnh c xy dng nhm phc v nhu cu cho sinh vin vi cc hnh khi n gin nhng a n mt hiu qu thm m hi ha v ph hp vi cng nng s dng.ii.phng hng thi cng v tng qut ton cng trnh1.iu kin kh hu - a cht cng trnh

- Qua ti liu kho st a ca khu vc cho thy cng trnh c xy dng trn nn t kh bng phng v gm c cc lp a cht sau:

+ Lp 1: lp t p dy 1,5m

+ Lp 2: st pha xm g dy 8m

+ Lp 3: st pha xm tro dy 8m

+ Lp 4: ct pha dy 6m

+ Lp 5: ct ht va cha gp y trong l khoan. y l lp t kh tt cho vic t mng cng trnh.

- Mc nc l loi nc khng p, khng xut hin trong phm vi kho st. Vi c im a cht nh trn ta nn s dng loi mng cho cng trnh l mng cc i thp vi chiu su kho st nm trn mc nc ngm.2. Tng quan v kt cu quy m cng trnh

- Gii php thit k phn mng: kt cu mng l mng cc BTCT i thp, dng cc c tit din 30x30 cm, di 24m gm 3 on, mi on di 8m ni vi nhau. Cc c thi cng cm vo lp t 5 mt on 1,5m.

+ i cc t lp t 1 (t lp), y i t ti ct -1,5m so vi ct t t nhin, i cc cao 90cm, t trn lp BT 4x6 c cp bn B7,5 dy 10 cm.

+ Dng cc BTCT, mi cc t ct -25.450m.

- o t c gii kt hp th cng.

- Kt cu cng trnh l kt cu khung BTCT, c xy tng chn 220, sn sn ton khi vi h dm. Ton b cng trnh l 1 khi thng nht, khng c khe ln.

+ Cng trnh l 1 ta nh 10 tng, cao 37,85m, tng 1 cao 3m, cc tng 2-4 cao 4,5m, tng mi v cc tng cn li cao 3,6m.

+ Chiu rng cng trinh B=20,9m, chiu di L=46,5m.

+ Mt t t nhin ngoi nh -0.45m so vi ct 0.00 ca cng trnh.

- Vn khun dng vn khun nh hnh bng thp.

- Ct thp c gia cng bng my t ti xng t ti cng trng v oc bo qun trong kho kn.

- B tng s dng cho cng trnh l btng thng phm hoc btng trn ti cng trng.3. Ngun nc thi cng

Cng trnh c t trong thnh ph, v vy nc phc v cho sinh hot v thi cng c ly trc tip t mng li cp nc ca thnh ph.4. Ngun in thi cng

S dng in ca mng in thnh ph, ng thi cn d phng 1 my pht in m bo lun c in ti cng trng trong trng hp mng in ca thnh ph c s c.5. Cung cp vt t

Cng trnh nm trong thnh ph nn v vy c rt nhiu cng ty cung ng vt t, my mc v thit b thi cng. Vt t c vn chuyn n cng trng bng t.6. Giao thng

Xung quanh cng trng l h thng ng s c lm sn nn rt thun tin cho vic vn chuyn vt t v xe, my lu thng.

Lp cc hng ro bng tn xung quanh cng trng.

7. B tr h thng in nc

H thng in nc c ly t h thng cung cp in nc ca thnh ph, ta thit lp cc tuyn dn vo cng trng nhm s dng cho cng tc thi cng cng trnh, sinh hot tm thi cho cng nhn v cn b k thut.

8. Xy dng cng trnh tm

Kho bi cha vt liu

Cc phng iu hnh cng trng, phng ngh tm cho cng nhn

Nh n, trm y t.

Chng ii:Thit k bin php k thut thi cngThi cng phn ngmNi dung cng vic phn ngm

- Thi cng h cc BTCT

- Thi cng o t

- Thi cng mng

- Thi cng btng ton khi mng, cc kt cu ngm khc.

- Lp t h mngi. lp bin php thi cng cc1. Cng tc chun b:

a.Mt bng

- Ngin cu k h s ti liu quy hoch , kin trc, kt cu v cc ti liu khc ca cng trnh, ti liu thi cng v ti liu thit k v thi cng cc cng trnh ln cn.

- Nhn bn giao mt bng xy dng.

- Gii phng mt bng, pht quang thu dn, san lp cc h rnh.

- Tiu thot nc mt.

- Xy dng cc nh tm : bao gm xng v kho gia cng ln tri tm, nh v sinh . . .

- Lp cc h thng in nc.

b. Gic mng cng trnh:

- Xc nh tim ct cng trnh, dng c bao gm dy gai dy km, dy thp 1 ly, thc thp, my kinh v my thu bnh . . .

-T bn v h s v khu t xy dng ca cng trnh, phi tin hnh nh v cng trnh theo2 mc chun theo bn v

-T mc chun xc nh cc im chun ca cng trnh = my kinh v: t im 1 gc tri ca cng trnh (theo hng vo), xc nh im 2 cch 50(m) theo phng song song vi ng, xc nh im 3 cch 28 (m) theo phng vung gc vi ng ta c 1 im gc ca cng trnh.T im chun ny ta xc nh nt cc im chun khc ca cng trnh.

-T cc im chun ta xc nh cc ng tim cng trnh theo 2 phng ng nh trong bn v ng du cc ng tim cng trnh bng cc cc g sau dng dy km cng theo 2 ng cc chun, ng cc chun phi cch xa cng trnh t 3,4 m khng lm nh hng n thi cng.

-Da vo cc ng chun ta xc nh v tr ca tim cc , v tr cng nh kch thc h mng.2. u nhc im ca thi cng p cc

Cc p l cc c h vo trong t tng on bng kch thu lc c ng h o p lc.

u im ni bt ca cc p l thi cng m, khng gy chn ng i vi cc cng trnh xung quanh, thch hp cho vic thi cng trong thnh ph, c tin cy, tnh kim tra cao, cht lng ca tng on cc c th di lc p, xc nh c lc dng p.

Nhc im. B hn ch v kch thc v sc chu ti ca cc, trong mt s trng hp khi t nn tt th rt kh p cc qua a ti su thit k.3. La chn phng n p cc.

Hin nay c 2 phng n p cc: Nu p cc xong mi xy dng i cc v kt cu bn trn gi l phng php p trc. Cn nu xy dng i trc sn cc l ch sau p cc qua l ch ny gi l phng php p sau, phng php p sau p dng cho cng trnh ci to, xy chn trong iu kin mt bng xy dng cht hp.

Trong iu kin cng trnh xy dng ca ta c tin hnh t u nn ta s dng phng php p trc,

Trnh t thi cng: H tng on cc vo trong lng t bng thit b p cc, cc on cc c ni vi nhau bng phng php hn. Sau khi h on cc cui cng vo trong t phi m bo cho mi cc su thit k.

4. Cc yu cu k thut i vi vic hn ni cc.

B mt b tng u 2 on cc ni phi tip xc kht, trng hp tip xc khng kht phi c bin php chn cht.

Khi hn cc phi s dng phng php hn leo(hn t di ln trn) i vi cc ng hn ng.

Kim tra kch thc ng hn so vi thit k,

ng hn ni cc on cc phi c trn c 4 mt cc. Trn mi mt chiu di ng hn khng nh hn 10 cm

5. La chn phng n thi cng p cc

Vic thi cng p cc ngoi hin trng c nhiu phng n, sau y l hai phng n thi cng ph bin.

*. Phng n 1:

Tin hnh o h mng n cao trnh nh cc sau a my mc, thit b p n v tin hnh p cc n su cn thit.

+ u im:

- o h mng thun li, khng b cn tr bi cc u cc nh phng n p cc trc.

- Khng phi p m.

+ Nhc im:

- nhng ni c mch nc ngm cao, vic o h mng trc, ri mi thi cng p cc kh thc hin c.

- Khi thi cng p cc gp tri ma, nht thit phi c bin php bm ht nc ra khi h mng.

- Vic di chuyn my mc, thit b phc v thi cng p cc gp nhiu kh khn.

- Vi mt bng khng rng ri, xung quanh ang tn ti cc cng trnh, vic thi cng theo phng n ny gp kh khn ln, i khi khng thc hin c.

Kt lun :phng n ny ch thch hp vi mt bng cng trnh rng, vic thi cng mng cn o thnh ao.

* Phng n 2:

Tin hnh san mt bng cho phng tin di chuyn thit b p v vn chuyn cc, sau tin hnh p cc theo yu cu thit k. Nh vy t c cao trnh nh cc thit k cn phi p m. Cn phi chun b cc on cc dn bng thp hoc BTCT cc p c ti chiu su thit k. Sau khi p cc xong tin hnh o t h mng thi cng phn i cc, h ging i cc.

+ u im:

- Vic di chuyn thit b p cc v cng tc vn chuyn cc c nhiu thun li, k c khi gp tri ma.

- Khng b ph thuc vo mch nc ngm

- Tc thi cng nhanh

+ Nhc im:

- Phi dng thm cc on cc dn p m, c nhiu kh khn khi p on cc cui cng xung chiu su thit k.

- Cng tc o t h mng kh khn, phi o th cng, kh c gii ho.

- Vic thi cng i, ging kh khn hn.

Kt lun :

Vic thi cng theo phng php ny thch hp vi mt bng thi cng hp, khi lng cc p khng qu ln.

Cn c vo u nhc im ca 2 phng n nu trn, cn c vo mt bng cng trnh ca ta khng c rng ri v xung quanh tn ti cc cng trnh khc ta chn phng n 2 thi cng.

Dng 2 my p cc thu lc tin hnh. S p cc xem trong bn v thi cng p cc . Cc c p m so vi ct thin nhin l 1,0 m6. Chn my thi cng

a cc xung su thit k cc phi qua cc tng a cht khc nhau. Ta thy cc mun qua c nhng a tng th lc p cc phi ph v c cu trc ca lp t di mi cc v m bo kt cu khng b v. Ngoi ra lc p phi m bo nh hn sc chu ti ca cc theo bn ca vn liu ch to cc.

Ta c: Pvl > Pep ( K1 x PnTrong :

- Pvl: Sc chu ti ca cc theo vt liu, Pvl = 157,54 T

- Peptk: Lc p ti thiu ca my

- Pn: Sc chu ti ca cc theo iu kin t nn, xc nh theo th nghim xuyn tnh CPT Pn = PSPT 75 T

- K1: h s an ton thi cng cho kt cu chu nn, ly bng h s tnh sc chu ti ca cc theo t nn theo th nghim xuyn tnh CPT, chn K1 = 2

Ta c: 157,54(T) > Pep (2x 75 = 150(T)

a. Tnh, chn cc thng s ca my p

Tnh ng knh xi lanh:Lc p do my sinh ra:

*kTrong :

nk: l s qu kch c trong gi p, nk = 2.

K: h s vt ti k= 1,2-1,3

D: l ng knh xi lanh

Pd: l p lc du, Pd = (0,6 ( 0,7)pd; pd = (210 ( 310)kG/cm2(Pd = (126 ( 217)kG/cm2 ( Ly Pd = 150kG/cm2Vy ng knh xi lanh:

D= ,ep))eq \l(\r(,, ,d))eq \l(\l((*P*neq \l(\o\ac( ,k))))*k)))) = (cm)Chn my p cc c cc thng s k thut sau:

+ Lc p ln nht Pmax=120 T, gm hai kch thu lc mi kch c Pmax =60T

+ng knh xilanh thu lc Dxl =30 cm

+ Tit din cc p c n 30x30cm

* Chn gi p:

- Chn gi p nh sau:

+ Kch thc ca gi p nh sau: (chn trong 1 ln lp gi p c 6 cc nh hnh v)

Chiu di gi p: L = 2Lt +2Lat + Lcoc = 2.3+2.0,7+0,9.2= 9,2 (m)Chiu rng gi p: B = 2Bat +2Bcoc= 2.0,7+2.0,6 = 2,6 (m) Trong : L - chiu di dm chnh bn p;

B - chiu rng gi p;

Lt- chiu di i trng;

Lat- khong cch an ton;

Lcoc- khong cch cc;

Bat- khong cch an ton;

Bcoc- khong cch cc theo chiu rng;

b. Thit k gi p

c.Xc nh i trng

-p cc t gia ra bn ngoi, vi cc gia i i trng t 2 bn l nh nhau

+ Thit k gi p c cu to bng dm t hp thp t hp ch I, b rng 25cm cao 55cm, khong cch gia hai dm i trng 2,6 m

+ Ta s dng i trng c kch thc l 1x1x3mPt = 1.1.3.2,5 = 7,5 T

Tng ti trng ca i trng ti thiu phi ln hn Pp = 150 TVy s cc i trng ti thiu l:

B tr mi bn 15 i trng c tng ti trng l Q = 15x7,5 = 112 TC 2 bn l 225 T> 150 TS lng cc cn p ca khi chnh cng trnh l

+ Mng M1 c 12 mng, mi mng c 6 cc

12x6 = 72 (cc)

+ Mng M2 c 6 mng, mi mng c 14 cc

6x12 = 72 (cc)

+ Mng M3 c 4 mng, mi mng c 10 cc

4x9 = 36 (cc)

+ Mng M4 c 2 mng, mi mng c 35 cc

2x34 = 68 (cc)

==> Tng s cc ca cng trnh l:

72+72+36+68 = 248 (cc)Tng chiu di cc p: 248x24 = 5952 (m)

+ Xt iu kin chng lt theo phng ngang quang im A: (p cc s 1)

2Q.1,3>1,9.Pp => T

+ Xt iu kin chng lt theo phng ngang quang im B: (p cc s 1)

Q.7,7+Q.1,5>5,5Pp => T

+ Xt iu kin nng bng

2.Q>Pp => TVy s i trng ta chn nh trn l tha mn.d . Chn cu cho cng tc p cc:

Trng lng cc: 0,3.0,3.8.2,5 = 1,8(T) Vy ta ly H=12,5m tnh chiu di tay cn

- Chiu di tay cn yu cu:

- Tm vi yu cu:

Ry/c=R +L.cos=1,5 + 12,5.cos75=4,74(m)Ta c bng chn thng s cn trc:

Chn KX-5361 loi c chiu di tay cn l = 20m c cc thng s l:Qmin = 2 T ; Rmax = 10m ; Rmin = 6 m

Qmax = 8,5T ; Hmax = 16 m

7. Xc nh thi gian thi cng, s nhn cng phc v p.

T s lng cc cn p v nh mc ca my ta tnh ra c s ca my cn thit cho vic thi cng cng trnh. Nu s ca my qu ln ta c th tng s my p ln.

Tit din cc trong thi cng cng trnh l cc 30x30cm, tng chiu di l 5952 m, tra nh mc vi tit din cc 30x30 v my p >150T, chiu di ca cc L> 4m ta c nh mc l 6,37ca/100m cc. Tnh thi gian thi cng theo nng sut thc t = 100 ( 120md/ca.

Vy s ca my cn thit l

Vy thi cng ton b cc ca cng trnh th cn 60 ngy. Ta tin hnh chn 2 my thi cng cc v sau khi c s ca my, s my ta s thit k c s p cc chnh thc.S nhn cng phc v cho 1 ca my p:

iu khin my p cc : 1 cng nhn

iu khin cu cu cc : 1 cng nhn

Phc v treo mc h i trng, mc cc v lp cc vo gi p: 2 cng nhn

Th hn ni cc on cc : 2 cng nhn

Cn chnh my kinh v : 2 k s

=> Tng s nhn cng phc v 1 ca p l : 8ngi/ca

Cc c tin hnh p theo s khm cc theo i ta phi tin hnh p cc t ch cht hp kh thi cng ra ch thong, p theo s p ui. Dng hai my p hai khu vc khc nhau vi s cc tng ng nhau. Trong khi p nn p cc pha trong trc nu khng c th cc khng xung c ti su thit k hay lm trng ni nhng cc xung quanh do t b ln qu gii hn => ph hoi.

8. Bin php thi cng, k thut p cca. Chun b mt bng thi cng v cc

Vic b tr mt bng thi cng p cc nh hng trc tip n tin thi cng ca cng trnh.Vic b tr mt bng thi cng phi hp l cng vic khng b chng cho, cn tr ln nhau gip y nhanh tin thi cng, rt ngn thi gian thc hin thi cng cng trnh.

Cc phi c b tr trn mt bng sao cho thun li cho vic thi cng m vn khng cn tr my mc thi cng

V tr cc cc phi c nh du sn trn mt bng bng cc ct mc chc chn, d nhn.

Cc phi c vch sn cc ng trc s dng my ngm kinh v

*.Gic i cc trn mt bng

Trc khi thi cng cn phi kt hp vi ngi lm cng vic o c, tri v tr cng trnh trong bn v ra hin trng xy dng. Trn bn v thi cng tng mt bng phi c li o c v xc nh y to ca tng hng mc cng trnh, bn cnh phi xc nh li to , da vo vt chun sn c hay mc dn xut, mc quc gia, cch chuyn mc vo a im xy dng.

Tri li ghi trong bn mt bng thnh li trn hin trng v to ca gc nh gic mng. Ch ti s m rng do phi lm mi dc. Thc hin cc bin php nh du trc mng, ch n mi dc taluy ca h mng

Khi gic mng cn dng nhng cc g ng su cch mp o 2m, trn 2 cc ng ming g c chiu dy 20mm, bn rng 150mm, di hn mng phi o 400mm. ng inh ghi du trc ca mng v 2 mp mng. Sau ng 2 inh na vo thanh g gc ln gi l nga nh du trc mng.

Cng dy thp d = 1mm ni cc ng mp o. Ly vi bt rc ln dy thp cng mp mng ny lm c o.Phn o bng my cng ly vi bt nh du lun v tr.*Gic cc trong mng

Gic mng xong, ta xc nh c v tr ca i, ta tin hnh xc nh v tr cc trong i

phn mng trn mt bng, ta xc nh c tim i nh cc im chun. Cc im ny c nh du bng cc mc

Cng dy trn cc mc, ly thng bng, sau t tim o ra cc khong cch xc nh v tr tim cc theo thit k

Xc nh tim cc bng phng php th cng, dng qu di th t cc giao im trn dy xc nh tim cc xc nh tim cc thc di t, nh du cc v tr ny

- Dng my kinh v xc nh v tr tim cc.

- Dng 2 my kinh v t hai trc vung gc nh v tr cc. Ring my knh v thnh v v tr cc, phi dng my kim tr 2, ngoi vic a thng ng ca trc cc.

*.Cng tc chun b p cc

Cc p sau nn thi im bt u p cc tu thuc vo s tho thun gia thit k ch cng trnh v ngi thi cng p cc

Vn chuyn v lp rp thit b p cc vo v tr p m bo an ton

Chnh my cc ng trc ca khung my, ng trc kch v ng trc ca cc ng thng v nm trong mt mt phng, mt phng ny phi vung gc vi mt phng chun nm ngang (mt phng chun i mng). nghing ca n khng qu 5%

Kim tra 2 mc cu ca dn my tht cn thn kim tra 2 cht ngang lin kt dm my v lp dn ln b my bng 2 my

Khi cu i trng, dn phi c k tht phng, khng nghing lch, kim tra cc cht vt tht an ton.

Ln lt cu cc i trng ln dm khung sao cho mt phng cha trng tm 2 i trng trng vi trng tm ng th cc. Trong trng hp i trng t ngoi dm th phi k chc chn

Dng cu t hnh cu trm bm n gn dn my, ni cc gic thu lc vo gic trm bm, bt u cho my hot ng

Chy th my p kim tra n nh ca thit b (chy khng ti v c ti)

Kim tra cc v vn chuyn cc vo v tr cc trc khi p

*.Kim tra cc chi tit ni cc v my hn

Trc khi p cc i tr, phi tin hnh p lm th nghim nn tnh cc ti nhng im c iu kin a cht tiu biu nhm la chn ng n loi cc, thit b thi cng v iu chnh n thit k, s lng cn kim tra vi th nghim nn tnh l 1% tng s cc p nhng khng t hn 3 cc.

*.Chun b ti liu

Phi kim tra loi b cc cc khng t yu cu k thut

Phi c y cc bn bo co kho st a cht cng trnh, biu xuyn tnh, bn cc cng trnh ngm.

C bn v mt bng b tr li cc trong khi thi cng

C phiu kim nghim cp phi, tnh cht c l ca thp v b tng cc

Bin bn kim tra cc

H s thit b s dng p cc

b. Lp on cc u tin

*.Chun b

on cc u tin phi c lp chnh xc, phi cn chnh trc ca C1 trng vi ng trc ca kch v i qua im nh v cc sai lch khng qu 1cm

u trn ca cc c gn vo thanh nh hng ca khung my

Nu on cc C1 b nghing s dn n hu qu ca ton b cc b nghing

*.Tin hnh thi cng p cc

Khi y kch (hoc nh pittong) tip xc vi nh cc th iu chnh van tng dn p lc, nhng giy u tin p lc du tng dn u, on cc C1 cm su dn vo t vi vn tc xuyn # 1m/s.

Trong qu trnh p dng 2 my kinh v t vung gc vi nhau kim tra thng ng ca cc lc xuyn xung. Nu xc nh cc nghing th dng li iu chnh ngay.

Khi u cc C1 cch mt t 0,3 # 0,5m th tin hnh lp on cc C2, kim tra v mt 2 u cc C2 sa cha sao cho tht phng.

Kim tra cc chi tit ni cc v my hn.

Lp on cc C2 vo v tr p, cn chnh ng trc cc C2 trng vi trc kch v trc on cc C1, nghing # 1%

Tc ng ln cc C2 mt lc to tip xc sao cho p lc mt tip xc khong 3 - 4kg/cm2 ri mi tin hnh ni 2 on cc theo thit k

Lm tng t vi cc on cc sau

*.Thao tc p m

Trong qu trnh p cc, khi p cc ti on cui cng, ta phi c bin php a u cc xung mt ct m 2,6m vi ct t nhin. C th dng 2 phng php

Phng php 1: Dng cc ph

Dng mt cc BTCT ph c chiu di ln hn chiu cao t nh cc trong i n mt t t nhin mt on (1 - 1,5m) p h u cc xung cao trnh ct m cn thit.

Thao tc: Khi p ti on cui cng, ta hn ni tip mt on cc ph di # 2,5m ln u cc, nh du ln thn cc ph chiu su cn p xung khi p cc u cc s tng i u nhau, khng xy ra tnh trng nhp nh khng bng nhau, gip thi cng p u cc v lin kt vi i thun li hn. xc nh su ny cn dng my kinh v t ln mt trn ca dm thp ch I xc nh cao trnh thc t ca dm thp vi ct 0,00, tnh ton xc nh c chiu su cn p v nh du ln thn cc ph (chiu su ny thay i theo tng v tr mt t ca i m ta t dm thp ca my p cc). Tin hnh thi cng cc ph nh cc chnh ti chiu su vch sn trn thn cc ph.

u im: khng phi dng cc p m nhng phi ch to thm s mt di cc BTCT lm cc dn, thi cng xong s p i gy tn km, hiu qu kinh t khng cao.Phng php 2: Phng php p m

Phng php ny dng mt on cc dn p cc xung ct m thit k sau li rt cc dn ln p cho cc khc, cu to cc p m do cn b thi cng thit k v ch to.

Cc p m c th l bng BTCT hoc thp

V hnh trnh ca pittng my p ch p c cch mt t t nhin khong 0,6 - 0,7m, do vy chiu di cc c ly t cao trnh nh cc trong i n mt t t nhin cng thm mt on 0,7m l hnh trnh pittng nh trn, c th ly ra thm 0,5m na gip thao tc p d dng hn.

u im: Khng phi dng cc ph BTCT, hiu qu kinh t cao hn, cc dn lc ny tr thnh cc cng c trong vic h cc xung ct m thit k.

Nhc im: thao tc vi cc dn phi thn trng trnh lm nghing u cc chnh v cc dn ch lin kt khp tm thi vi u cc chnh (chp m u cc ln u cc). Vic thi cng nhng cng trnh c tng hm, su y i ln hn thi cng dn kh hn, khi p xong rt cc ln kh khn hn, nhiu trng hp cc p chnh b nghing.

c. Kt thc cng vic p cc

Cc c coi l p xong khi tho mn 2 iu kin:

Chiu di cc p vo t nn trong khong Lmin # Lc # Lmax

Trong :

Lmin , Lmax l chiu di ngn nht v di nht ca cc c thit k d bo theo tnh hnh bin ng ca nn t trong khu vc

Lc l chiu di cc h vo trong t so vi ct thit k;

Lc p trc khi dng trong khong (Pep) min # (Pep)KT # (Pep)max

Trong :

(Pep) min l lc p nh nht do thit k quy nh;

(Pep)max l lc p ln nht do thit k quy nh;

(Pep)KT l lc p ti thi im kt thc p cc, tr s ny c duy tr vi vn tc xuyn khng qu 1cm/s trn chiu su khng t hn ba ln ng knh ( hoc cnh) cc.

Trng hp khng t 2 iu kin trn ngi thi cng phi bo cho ch u t v thit k s l kp thi khi cn thit, lm kho st t b sung, lm th nghim kim tra c c s l lun s l.

d. Cc im cn ch trong thi gian p cc

Vic ghi chp lc p theo nht k p cc nn tin hnh cho tng mt chiu di cc cho ti khi t ti (Pep)min, bt u t su ny nn ghi cho tng 20cm cho ti khi kt thc, hoc theo yu cu c th ca T vn, Thit k.

Ghi chp lc p u tin khi mi cc cm su vo lng t t 0,3 0,5m th ghi ch s lc p u tin sau c mi ln cc xuyn c 1m th ghi ch s lc p ti thi im vo nht l p cc

Nu thy ng h o p lc tng ln hoc gim xung 1 cch t ngt th phi ghi vo nht k p cc s thay i .

Nht k phi y cc s kin p cc c s chng kin ca cc bn c lin quan.

*.Ghi chp theo di lc p theo chiu di cc

Khi mi cc cm su vo t t 30- 50cm th ghi ch s lc u tin. Sau c mi ln cc i xung su c 1m th ghi lc p ti thi im vo s nht k p cc

Nu thy ch s trn ng h o p lc tng ln hoc gim xung t ngt th phi ghi

vo nht k cng su v gi tr lc p thay i t ngt ni trn. Nu thi gian thay i lc p ko di th ngng p v tm hiu nguyn nhn, xut phng php s l.

S nht k c ghi mt cch lin tc n ht su thit k, khi lc p tc dng ln cc c gi tr bng 0,8.Ppmin th ghi li su v gi tr

Bt u t su c p lc P=0,8Ppmin, ghi chp tng ng vi tng su xuyn 20 cm vo nht l, tip tc ghi nh vy cho n khi p xong 1 cc.

*.Thi im kha u cc

Mc ch ca kha u cc

Huy ng cc vo thi im thch hp trong qu trnh tng ti ca cng trnh khng chu nhng ln hoc ln khng u.

i vi cc p trc khi thi cng i, vic kha u cc do CT v ngi thi cng quyt nh

Thc hin vic kha u cc

Sa u cc cho ng cao trnh thit k

b xung quanh bng ct ht trung, m cht cho ti cao ca lp b tng lt

t li thp cho cc

e. X l cc s c khi thi cng p cc

Do cu to a cht di nn t khng ng nht nn thi cng p cc c th xy ra cc s c sau:

Khi p n su no cha n su thit k nhng p lc t, khi phi gim bt tc , tng lc p ln t t nhng khng ln hn Pp max. Nu cc vn khng xung th ngng p v bo co vi bn thit k kim tra s l.

Nu nguyn nhn l do lp ct ht trung b p qu cht th dng p cc li mt thi gian ch cho cht lp t gim dn ri p tip

Nu gp vt cn th khoan ph, khoan dn, p cc to l

Khi p n su thit k m p lc u cc vn cha t n yu cu theo tnh ton. Trng hp ny xy ra thng do khi u cc vn cha n lp ct ht trung, hoc gp cc thu knh, t yu, ta ngng p cc v bo vi bn thit k kim tra, xc nh nguyn nhn v tm bin php s l.

Bin php x l trong trng hp ny l ni thm cc khi kim tra v xc nh r lp t bn di l lp t yu sau p cho n khi t p lc thit k.

f. Kim tra sc chu ti ca cc

Sau khi p xong ton b cc ca cng trnh phi kim tra nn tnh cc bng cch thu cc c quan chuyn kim tra

S cc phi kim tra bng 1% tng s cc cng trnh, nhng khng nh hn 3 cc

Sau khi kim tra phi c kt qu u v kh nng chu ti, ln cho php, nu t yu cu c th tin hnh o mng thi cng b tng i.

g. An ton lao ng trong thi cng p cc

Phi hun luyn cho cng nhn, trang b bo h v kim tra an ton thit b p cc

Chp hnh nghim chnh quy nh trong an ton lao ng v s dng vn hnh kch thy lc, ng c in cn cu,...

Cc khi i trng phi c xp theo nguyn tc to thnh khi n nh, khng c khi i trng nghing v ri trong qu trnh p cc

Phi chp hnh nghim, cht ch quy trnh an ton lao ng trn caoii. lp bin php thi cng tCng tc o t c chia lm hai giai on:

- o mng bng my: Dng my bc mt lp t t ct t nhin ti cao trnh y ging mng,t trong phm vi cc i mng c tr li o th cng do vic o t bng my d va chm u cc lm nh hng cht lng cc . Lng t o ln mt phn li sau ny lp mng, cn li c a ln xe t ch i.

- o v sa mng bng th cng: V cc h mng c u cc nn thi cng o t bng my khng nng sut. Vy ta chn phng n o h mng i bng th cng.

Khi lng t o c tnh ton nh trong bng tnh khi lng.1.Thit k h mng.

la chn phng n o t tt nht, trc ht ta cn thit k h o cho tng mng ring bit, ri t xc nh tng th cc h mng trn mt bng, mt ct cc h mng la chn gii php o ti u.

Do mc nc ngm rt su (khng xut hin trong chiu su h khoan th nghim) nn ta khng cn b tr bin php h mc nc ngm. tiu thot nc mt cho cng trnh, ta o h thng mng xung quanh cng trnh vi dc i=3% chy v h ga thu nc v dng my bm bm i.

Mng nm trong 2 lp t: lp 1 l t p (ct) c h s mi dc l 0,67, lp 2 l st pha sm g trng thi do mm h s mi dc l 0,25. m bo an ton cho t khng tri xung h o ta o h mng vi h s mi dc l: m = 0,67Kch thc chiu rng v chiu di ca lp B tng lt mng ln hn kch thc chiu rng v chiu di ca i mng l 10 cm.Chiu su chn mng l: 1,5m so vi ct t t nhin v chiu dy lp lt mng 10cm, vy ta cn o h mng su H = 1,6 m.Kch thc chiu rng h mng: v h s mi dc l m = 0,67 v vy ming h mng s rng hn phn y l: (l = m.H = 0,67.1,6 = 1,1mChiu rng v chiu di ca y h mng ln hn chiu rng v chiu di ca i cc l 50 cm, khong cch ny phc v cng tc thi cng Btng lt mng, cng tc ct thp v dng lp vn khun. Vy chiu di v chiu rng ca y h mng ln hn i cc l: 2.50 = 100 cm.=> Nh vy phn h mng m rng mi bn s bng 1,1 + 0,5= 1,6m

2. Tnh ton khi lng o, p

Cn c vo s liu tnh ton phn kt cu, ta xc nh c chiu su chn i mng k c lp btng lt i l 1,6 m so vi ct t nhin. Vy ta s tin hnh o h mng xung ct -1,600 m so vi ct t t nhin (ct -2.050m) so vi ct 0.000. cho thun tin trong cc cng tc thi cng ta m rng thm mi bn i 500 cm tnh t mp i.2.1 La chn phng n o t.*.Phng n o hon ton bng th cng

Thi cng t th cng l phng php thi cng truyn thng,dng c lm t l dng c c truyn nh: xng, cuc, mai,cuc chim, ko ct t... vn chuyn t ngi ta dng quang gnh, xe ct kt mt bnh, xe ci tin... Nu thi cng theo phng php o t bng th cng th tuy c u im l n gin v c th tin hnh song song vi vic thi cng mng, d t chc theo dy chuyn, nhng vi khi lng cng kh ln th s lng cng nhn cng phi ln mi m bo c rt ngn thi gian thi cng..., do vy nu t chc thi cng khng kho th s gy tr ngi cho nhau dn n nng sut lao ng gim, khng m bo c tin .*. Phng n o hon ton bng my

Vic o t bng my s cho nng sut cao, thi gian thi cng ngn thi cng ngn, tnh c gii cao. Nu thi cng theo phng php ny th c u im ni bt l rt ngn thi gian thi cng, m bo k thut m tit kim c nhn lc. Nhng st y h o khong 20 cm ta phi o bng th cng sa li kch thc mng, nhm m bo chnh xc ct thit k, kt cu t di y mng s khng b ph hu.

*. Phng n kt hp gia c gii v th cng

-Phng n o bng c gii kt hp vi th cng c nhng u im ni bt sau:

+ Rt ngn thi gian thi cng

+ S dng my ca n v thi cng

+ m bo k thut, tit kim nhn lc

+ H gi thnh cng trnh

+ An ton lao ng cao.

Vi khi lng t o ca ta tng i ln, ng thi dy nhanh tin v tng nng sut ta chn phng n o t c gii kt hp vi th cng.

y l phng n ti u thi cng, ta s o bng my ti cao y ging mng v tra li din tch cc khm cc, phn t cn li s c thi cng bng phng php o th cng. Theo phng n ny ta s gim ti a thi gian thi cng v to iu kin cho phng tin i li thun tin khi thi cng.

==> Vy vi nhng phn tch nh trn y ta s la chn phng n o t bng my kt hp sa th cng2.2 Tnh ton khi lng o tTa s tin hnh o bng my theo kiu o ao n ct y ging mng, trong khi o ta cha li nhng lm t ti v tr nhng khm cc, lng t ny s c thi cng bng th cng.Khi lng t o bng my s c tnh bng 80% khi lng o ao, cn li l o bng th cng. (tnh gn ng)* Phn o bng myTin hnh o thnh ao tnh t ct t t nhin n ct y ging mng (tc ct -1.750 m so vi ct 0.000) c chiu su H=1,3 m.Khi lng o t c tnh vi h o hnh thang.

a=46,5+1,8+2x0,5=49,5 (m)b=20,9+1,2+0,86+2x0,5=23,96 (m)

c=46,5+1,8+2.1,6=51,5 (m)

d=20,9+1,2+0,96+2.1,6=26,26 (m)

==> vy tng khi lng o t bng my l :Vmy=1649.0,8= 1320(m3)*. Phn o bng th cng

c tnh bng 20% khi lng o ao trn v cng thm phn o tng h mng mt vi chiu cao l 0,3 m ( c n ct y i)Khi lng cc h mng c hnh dng n gin c tnh theo cng thc hnh thang v c th hin di bng sau:MngKch Thca(m)b(m)c(m)d(m)H(m)V mt h mng (m3)S LngTng

A (m)B (m)

M12,41,83,42,84,53,90,32,71232,3

M25,11,86,12,87,23,90,34,9629

M34,61,85,62,86,63,90,34,5417,7

Tng78,9

Mng M4:

a=12,96+2.0,5=13,96 (m)b=4,2+2.0,5=5,2 (m)

c=12,96+1+2.0,47=14,9 (m)

d=4,2+2.0,5+2.0,47=6,14 (m)H=0,3 (m)Vy:

Tr i th tch phn gch cho:Vgch=(2,76.2,4.0,3+6.2,4.0,3)=6,3(m3)==> Th tch khi lng t cn o thc t ca mng M4 lVtt=V5-Vgch=41-6,3=34,7 (m3)S lng mng M4 l 2 chic => V=2.34,7=69,4 (m3)

Tng khi lng t o bng th cng l: Vtc= 78,9+69,4+0,2.1649= 478 (m3)Vy:Vy Tng khi lng t c o th cng v o my l:

V= 1320+478=1798 (m3)3. Chn my o t, tnh ton my o v s ngi phc v my o

a. Nguyn tc chn my o

+ Chiu rng ming h o: c x d = 51,5 x 26,16 (m).

+ Chiu su h o :1,5 m.

+ Chiu cao ln nht: h ( hxe ti + 1m = 2,5 + 1 = 3,5m.

Hin nay ta c th dng cc loi my o gu thun, gu nghch o t mng cng trnh. Xt v u nhc im ca 2 loi my ny ta thy.

My o gu thun c cnh tay gu ngn v kho,my c th o c t cp I n cp IV, my c kh nng t hnh cao, c th lm vic m khng cn cc loi my khc h tr.Ngc li nhc im ca loi my ny l ch lm vic c nhng ni kh ro, khi o t my ng di h nn phi m ng cho my ln xung.

i vi my o gu nghch khi o my ng trn b nn n c th o c nhng ni c nc ngm. Khi o bng my my o gu nghch khng phi m ng ln xung, my c th o h c vch thng ng hoc mi dc. Thc t cng trnh ca ta lp t c o l lp t lp c su khng ln lm v kch thc h o cng khng qu ln nn ta chn my o gu nghch l hp l nht.

Da vo khi lng t o s b tnh ton, cp t o v trang thit b my mc thc t ca n v thi cng ta chn my o gu nghch, dn ng thy lc, m hiu E0-3322B1 c cc thng s k thut sau:

Cc thng s k thut ca my o c s hiu EO-3322B1

Thng sK hiuGa trn v

M hiuEO-3322B1

Dung tch guq0,5m

Bn knh o ln nhtRmax7,5m

Chiu cao nng ln nhth4,8m

Chiu su o ln nhtH4,2m

Trng lng myQ14,5T

Thi gian 1 chu k( khi quay 1 gc 90v t ln xe t vn chuyn)t

17s

B rng myb2,7m

Chiu cao myc3,84m

b. Tnh nng sut my o

Dung tch gu q =0,5(m3)

Bn knh hot ng ca cn theo phng ngang R=7,5(m)

vi o su ti a H = 4,2(m)

nng tay cn ti a h = 4,8(m)

Gc nng ca tay cn (=900

Thi gian hot ng 1 chu k tck =17

Trng lng my 14,5 (T) c : a =2,81(m) ; b =2,7(m) ; c =3,84(m)

Nng sut my o : N= q.

Trong :

Kd_H s y gu ly Kd =1,1

nck_S chu k trong 1 gi

Thi gian chu k : Tck= tck.Kvt.Kq H s ph thuc iu kin t ca my xc khi t ln thng xe Kvt=1,1

Kq_H s ph thuc vo gc quay cn khi (=900 ta c Kq=1

Ktg_H s s dng thi gian Ktg= 0,8

Tck= 17x1,1x1=18,7( nck==192,5

Nng sut ca my :

= 70,59(m3/h)

Khi lng t m my o c trong mt ca (mt ca 8 gi):

Vt = 70,59x8 = 564,71 m3/ca

( S ca my m my phi lm vic o xong:

EMBED Equation.DSMT4 Vy ta chn 3 ca.

Vi cng trnh ta ch cn o my ti su H = 1,3m.Chn 1 my mi my lm vic 3 ca.

My o gu nghch E0-3322B14.Tnh s lng xe t vn chuynChn xe KOMATSU HD 180-4 c cc thng s sau:

+ Sc ch ln nht: 18T

+ Vn tc di chuyn: 48 km/h

+ Dung tch hnh hc: 10,7m3+ Trng lng: 16,79T

+ Bn knh quay nh nht: 9m

+ H s s dng thi gian: Ktg=0,85-0,9 ly Ktg=0,9

- Tnh ton s xe cn dng.

+ Do xe i trong thnh ph nn ly vn tc trung bnh: Vtb=30km/h

- Thi gian vn chuyn mt chuyn xe l: t = tb + ti + t + tv

+ tb: thi gian t ln xe tb=15+ ti : thi gian vn chyn i ti ni , qung ng l 10km, V=30km/h

( ti =

+ t : thi gian v quay xe t=5

+ tv: thi gian xe chy v tv=ti=20

Vy t = 15+20+5+20=60

+ Mt ca mi xe chy c: chuyn

- Chn sc ch ca xe l 14T tng ng vi th tch thng cha V=8m3

Trong 1 ca xe khi lng t vn chuyn c l: 7,2x8x0,9 = 51,84 m3

( S ca xe cn thit vn chuyn ht s t l: = 23,12 (ca xe) chn 23 (ca xe)Mt khc s ca my o l 3 (ca)

( S xe cn thit vn chuyn cho mt ca my o l: 23/3= 7,6 (xe) chn 8 (xe)5.S o t cho my o

6.Bin php thi cng t:

* Bin php o t bng my:

Mt bng cng trnh b gii hn. t ch t khng i vo nhng v tr o t. Ta chn phng n cho my o i ngang theo chiu ngang nh, my o gu nghch di chuyn li, o dc bn. Khi t ln xe, t lun chy mp bin v chy song song vi my o gc quay cn khoang 900. Cn ch n cc khong cch an ton:

( Khong cch t mp t n mp my o khong 3 m ;

( Khong cch t gu o n thng t: 0,5 ( 0,8 m ;

( Khong cch mp my o n mp h o :1 ( 1,5 m ;

Trc khi tin hnh o t cn cm cc ct mc xc nh kch thc h o v tr ca cc cc my o khng di chuyn trn cc u cc

Khi o cn c 1 ngi lm hiu, ch ng trnh o vo v tr u cc, nhng ch o khng lin tc cn ri vi bt nh du ng o.

* Bin php o t bng th cng

- Sau khi my o o xong phn t ca mnh, ta tin hnh sa h mng bng th cng trnh va chm vo my.- Chun b y dng c lao ng: mai, xng, cuc o v thng, st v vn chuyn ngoi bng st, ri vn chuyn ra ngoi bng xe ci tin,..c th trc tip vo xe ci tin.

- Xe vn chuyn t khng c ng trong phm vi nh hng ca mt trt.

- K thut o: Phi nh du phm vi o bng cc cc tiu hay rc vi bt, nn o theo hng t xa v gn pha t d thi cng. o theo ng k thut, khi o n u, sa h mng n trnh lp li mt im qu nhiu ln khng t c hiu qu cao khi lao ng .

- Gi kh h mng thi cng mng.* Thot nc trong qu trnh o t :

Nc c gom v cc h thu nc tm thi thng qua cc rnh thu nc c o su hn ct trung bnh ca cc lp t o

Cc rnh thu nc c to dc t 2%-5% v pha h thu nc tm thi. Ti cc h thu nc t cc my bm vi cng sut thch hp, lin tc a nc ln khi h v vo h thng thot nc cng trng, ri ra h thng thot nc thnh ph.

* Thot nc trong qu trnh thi cng i cc v ging mng :

Giai on thi cng i cc, ging mng: Cc h mng ca i cc l cc h c lp, c kch thc ln. Do bin php la chn l t my bm trc tip cho tng h.

* S c thng gp khi o v cch khc phc:

Khi o t h mng c rt nhiu s c xy ra, v vy cn phi ch c nhng bin php phng nga, hoc khi xy ra s c cn nhanh chng khc phc m bo yu cu v k thut v kp tin thi cng.ang o t, gp tri ma lm cho t b st l xung y mng. Khi tnh ma nhanh chng ly ht ch t sp xung, lc vt t sp l cn cha li 10 cm y h o so vi ct thit k. Khi bc b lp t cha li ny (bng th cng) n u phi tin hnh lm lp lt mng bng b tng gch v ngay n .

C th ng ngay cc lp vn v chng thnh vch sau khi dn xong t sp l xung mng.

Cn c bin php tiu nc b mt khi gp ma nc khng chy t mt xung y h o. Cn lm rnh mp h o thu nc, phi c rnh, con trch quanh h mng trnh nc trn b mt chy xung h o.

Khi o gp "m ci nm chm" hoc khi rn nm khng ht y mng th phi ph b thay vo bng lp ct pha dm ri m k li cho nn chu ti u.

Trong h mng gp ti bn: Phi vt sch ly ht phn bn ny trong phm vi mng. Phn bn ngoi mng phi c tng chn khng cho lu thng gia 2 phn bn trong v ngoi phm vi mng. Thay vo v tr ca ti bn ly i cn ct, t trn dm, hoc cc loi t c gia c do c quan thit k ch nh.* Nghim thu h o- Nghim thu kch thc hnh hc h o v chiu rng, di v chiu cao ca h c m bo vi thit k khng, nu c sai lch th phi nm trong gii hn cho php.

- V tr cng trnh trn mt bng v kch thc. - Cao ca cng trnh.

- nging mi dc cng trnh. 8. Cc bin php an ton lao ng trong cng tc o t* Khi o t bng my:- Trong thi gian my hot ng, cm mi ngi i li trn mi dc t nhin, cng nh trong phm vi hot ng ca my, khu vc ny phi c bin bo.

- Khi vn hnh my phi kim tra tnh trng my, v tr t my, thit b an ton phanh hm, tn hiu, m thanh, cho my chy th khng ti.

- Khng c thay i nghing ca my khi gu xc ang mang ti hay ang quay gn, cm hm phanh t ngt.

- Trong mi trng hp khong cch gia my o v thnh h o phi > 1,5 m.

* o t bng th cng

- Phi trang b dng c cho cng nhn theo ch hin hnh.- Cm ngi i li trong phm vi 2m tnh t mp xung quanh h trnh tnh trng ri xung h.

- Khng cht nng b h o. Phi cch mp h t nht 2m mi c xp t nhng khng qu nng.

- o t h mng sau mi trn ma phi rc ct vo bc thang ln xung trnh trt- Cm b tr ngi lm vic trn ming h trong khi ang c vic bn di h o trong cng mt khoang m t c th ri, l xung ngi bn di.

III. LP BIN PHP THI CNG GING V I MNG

1. Tnh khi lng cho cc cng vic chnh

a. Vn khun cho cng tc b tng i mng , ging mngKhi lng vn khun i mng ging mngCu kinKch thc(m)Din tchDin tch l gingDin tch thcS lngTng din tch

DiRngCaom2m2m2m2m2

i M12,41,80,97,560,487,081284,96

i M25,11,80,912,420,4811,94671,64

i M34,61,80,911,520,4811,04444,16

i M412,94,20,978,21,6876,522153,04

GM 15,40,40,66,481490,72

GM 24,20,40,65,041470,56

GM 33,20,40,63,8427,68

GM 41,20,40,61,4422,88

GM 55,70,40,66,841282,08

Tng khi lng607,7

b. Cng tc b tng i mng, ging mng

Khi lng b tng i mng ging mng

Cu kinKch thc(m)Th tchS lngTng th tch

DiRngCaom3ckm3

i M12,41,80,93,891246,66

i M25,11,80,98,26649,57

i M34,61,80,97,45429,81

i M412,94,20,929,98259,96

GM 15,40,40,61,301418,14

GM 24,20,40,61,011414,11

GM 33,20,40,60,7721,54

GM 41,20,40,60,2920,58

GM 55,70,40,61,371216,42

Tng khi lng236,78

c.Cng tc ct thp mng:

Do trong thit k nn mng cng trnh ch thit k cho hai i mng M1,M2, cc mng cn li ch xc nh s b vi hm lng ct thp 1%

Khi lng ct thp mng

Cu kinTh tch b tngTrng lng thpHm lng ct thpS lng cu kinKL/1CKKhi lng

(m3)(T/m3)%ck(Tn)(Tn)

i M13,897,850,010120,313,66

i M28,267,850,01060,653,89

i M37,457,850,01040,582,34

i M429,987,850,01022,354,71

GM 11,307,850,010140,101,42

GM 21,017,850,010140,081,11

GM 30,777,850,01020,060,12

GM 40,297,850,01020,020,05

GM 51,377,850,010120,111,29

Tng khi lng18,59

2. Khi lng cho cc cng tc khc

a. Vn khun cho cng tc b lt i mng, ging mng

Chiu dy lp b tng lt l 10(cm). Dng cc thanh g c chiu dy t(34)cm cao 10(cm) , ng thnh hnh ch nht v dng g (2x4)cm ging bn gc cho n nh khung.

Khi lng vn khun btng lt y i,ging mngCu kinKch thc(m)Din tchS lngTng din tch

DiRngCaom2ckm2

i M12,620,10,921211,04

i M25,320,11,4668,76

i M34,820,11,3645,44

i M413,14,40,13,426,8

GM 15,60,60,11,121415,68

GM 24,40,60,10,881412,32

GM 33,40,60,10,6821,36

GM 41,40,60,10,2820,56

GM 55,90,60,11,181214,16

Tng khi lng76,12

b. Cng tc b tng lt i mng, ging mng

Khi lng btng lt i,ging mng

Cu kinKch thc(m)Th tchS lngTng th tch

DiRngCaom3ckm3

i M12,620,10,52126,24

i M25,320,11,0666,36

i M34,820,10,9643,84

i M413,14,40,14,0128,02

GM 15,60,60,10,34144,70

GM 24,40,60,10,26143,70

GM 33,40,60,10,2020,41

GM 41,40,60,10,0820,17

GM 55,90,60,10,35124,25

Tng khi lng37,68

c. Cng tc ph b tng u cc.

Khi lng b tng p u ccTn cu kinng knh (m)Din tch (m2)Chiu di (m)Khi lng (m3)S lngTng khi lng (m3)

Cc BTCT0,30,090,40,0362488,93

3. S b chn bin php k thut b tng.Do iu kin thi cng trong thnh ph v khi lng b tng mng khng qu ln, do vy s dng l b tng thng phm c ch trn sn trong nh my v ch n cng trnh bng xe chuyn dng. b tng c thc hin bng my bm t hnh.

4. Thit k vn khun mng

a. La chn vt liu lm vn khun mng.

S dng vn khun nh hnh bng kim loi. Do cng ty NITETSU ca Nht Bn ch to.

B vn khun bao gm :

- Cc tm khun chnh.

- Cc tm gc (trong v ngoi).

Cc tm vn khun ny c ch to bng tn, c sn dc v sn ngang dy 3mm, mt khun dy 2mm.

- Cc ph kin lin kt : mc kp ch U, cht ch L.

- Thanh chng kim loi.

Cc c tnh k thut ca tm vn khun c nu trong cc bng sau:Bng 1: Bng c tnh k thut ca tm khun phng

Rng

(mm)Di

(mm)Cao

(mm)Mmen qun

tnh (cm4)Mmen khng

un (cm3)

300

300

300

300

300

250

250

250

250

250

220

220

220

220

220

200

200

200

200

200

150

150

150

150

150

100

100

100

100

1001800

1500

1200

900

600

1800

1500

1200

900

600

1800

1500

1200

900

600

1800

1500

1200

900

600

1800

1500

1200

900

600

1800

1500

1200

900

60055

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

55

5528,46

28,46

28,46

28,46

28,46

28,46

28,46

28,46

28,46

28,46

20,2

20,2

20,2

20,2

20,2

17,63

17,63

17,63

17,63

17,63

15,63

15,63

15,63

15,63

15,63

14,53

14,53

14,53

14,53

14,536,55

6,55

6,55

6,55

6,55

4,57

4,57

4,57

4,57

4,57

4,42

4,42

4,42

4,42

4,42

4,3

4,3

4,3

4,3

4,3

4,08

4,08

4,08

4,08

4,08

3,86

3,86

3,86

3,86

3,86

Bng 2: Bng c tnh k thut tm khun gc ngoi

KiuRng (mm)Di (mm)

100(100

1800

1500

1200

900

750

600

Bng 3: Bng c tnh k thut tm khun gc trong

KiuRng (mm)Di (mm)

700

600

300

1500

1200

900

150(150

100(100

1800

1500

1200

900

750

600

b. Thit k vn khun mng ( vn khun i M3)

b.1-B tr h vn khun:

Kch thc i : 5,1x1,8x0,9 (m)

Kch thc ging : 0,4x0,6 (m)

Hnh v cu kin:

Do mng c chiu cao 90 cm nn ta chn vn khun ng, chn loi vn khun c chiu di 90 cm

- 4 gc, dng 4 tm vn khun gc ngoi c kch thc 10x10x90 cm

- Cch cnh di dng cc tm vn khun phng c kch thc (30x90 cm)nhng ch cn thiu ghp thm cc tm vn khun gc trong c kch thc ( 15x15x90 cm) v vn khun phng (15x90 cm)

Ta c bng thng k cc loi vn khun cn dng, hnh v cu to vn khun mt mt thnh i.

Tn vn khunRngDiDyS lng(1 mng)

(mm)(mm)(mm)

Tm chnh 3009005534

150900554

100900556

b.2 Tnh ton lc tc dng ln vn khun:

- Cc lc ngang tc dng vo vn khun:Vn khun thnh i mng chu ti trng tc ng l p lc ngang ca hn hp b tng mi v ti trng ng khi b tng vo ct pha bng my bm b tng.

Theo tiu chun thi cng b tng ct thp TCVN 4453-95 th p lc ngang ca va b tng mi xc nh theo cng thc (ng vi phng php m di).

+ p lc ngang ti a ca va b tng ti:

P= n.(.H = 1,3(2500(0,7 = 2275(kg/m2)

P1tc =( .H = 2500 x0,7 =1750 (Kg/m2)

Trong :H = 0,7m l chiu su nh hng ca m di.

(- Dung trng ca btng: ( = 2500Kg/m3 n- H s tin cy n = 1,3

+Ti trng do chn ng khi b tng ng vi phng php b tng bng my bm b tng tc dng vo vn khun:

P= 1,3(400 =520( Kg/m2)

P2tc = 400( Kg/m2)

+Ti trng do m va b tng bng my:

P= 1,3(200= 260 (Kg/m2)

P3tc = 200( Kg/m2)

Tuy nhin vi cp pha ng, thng khi th khng m nn chn Pmax=( P2,P3) = P2+ Ti trng ngang tng cng tc dng vo vn khun l:

Ptt = P1tt +P2tt =2275 + 520 = 2795( kG/m2 ) = 0,279( kG/cm2)

Ptc = 1750 + 400 = 2150 (kG/m2 )= 0,215 )kG/cm2)

- S tnh ton: ly ra 1 tm vn khun rng 0,3 m di 0,9m tnh, coi l dm n gin ta trn gi l cc thanh sn ngang.

+ Ti trng tc dng theo chiu rng vn khun (0,3 m) l:

qtt = Ptt(0,3 = 2795x0,3 = 838,5(Kg/m) = 8,385(Kg/cm)

qtc = Ptc(0,3 = 2150x0,3 =645 (Kg/m) = 6,45 (Kg/cm)

- Kim tra vn khun:

+ iu kin bn ca tm vn khun :

Mmax=( R.W

Trong :

R - cng ca vn khun kim loi R=2100 Kg/cm2W - mmen khng un ca vn khun.vi b rng 300 tra bng ta c W = 6,55 cm3

=> =>

Chn l=80cm

Vy ta chn khong cch gia cc np ngang l l=80cm. V b tr nh sau:

a.3 Kim tra kch thc sn ngang v tnh khong cch sn ng

- Chn sn ngang bng g tit din l 100x100 mm

s tnh sn ngang c coi l 1 dm lin tc gi ln cc gi ta l cc sn dc.

Ti trng:

Ti trng tc dng ln sn ng di dng lc phn b u vi chiu rng ti tc dng bng khong cch cc sn ngang (0,8m)

qtt= 0,8xPtt= 0,8x 2795= 2236 kG/m.

qtc= 0,8xPtc= 0,8x 2150= 1720 kG/m.

M men un ln nht trong sn ng: M =

+Khong cch sn theo iu kin bn:

Sn ngang bng g 100x100 c:

, , [(]=110kG/cm2.

T iu kin bn ta suy ra:

S b chn khong cch cc sn ng l 60 cm

Vy chn khong cch cc sn ng l l= 60cm.

b.5 Kt qu tnh ton.

+ Hnh v kt qu tnh ton nh sau

c. Tnh ton thit k vn khun ging mng:

- Tnh in hnh cho GM trc B nhip 1-2( 5,7 x0,4x0,6 m)

- Theo chiu cao thnh ging ta chn 2 tm vn khun 300x1200) v 2 tm vn khun 300x900 xp nm ngang theo chiu di ging mng.

Tn vn khunRngDiDyS lng(1 ging)

(mm)(mm)(mm)

Tm chnh 3001200558

Tm ph300900552

T hp vn khun ging mng GM

- Nhng ch no b h, thiu vn khun ta b vo bng nhng tm vn g hoc nhng tm vn khun khc cho kn tu theo yu cu thc t.

- Cu to vn khun ging:Cc vn khun thp nh hnh c t hp theo phng ngang

- Ti trng tc dng ln vn khun thnh ging mng:

+ p lc ngang ti a ca va b tng ti:

P= n.(.H = 1,3(2500(0,7 = 2275(kg/m2)

P1tc =( .H = 2500 x0,7 =1750 (Kg/m2)

Trong :H = 0,7m l chiu su nh hng ca m di.

(- Dung trng ca btng: ( = 2500Kg/m3 n- H s tin cy n = 1,3

+Ti trng do chn ng khi b tng ng vi phng php b tng bng my bm b tng tc dng vo vn khun:

P= 1,3(400 =520( Kg/m2)

P2tc = 400( Kg/m2)

+Ti trng do m va b tng bng my:

P= 1,3(200= 260 (Kg/m2)

P3tc = 200( Kg/m2)

Tuy nhin vi cp pha ng, thng khi th khng m nn chn Pmax=( P2,P3) = P2+ Ti trng ngang tng cng tc dng vo vn khun l:

Ptt = P1tt +P2tt =2275 + 520 = 2795( kG/m2 ) = 0,279( kG/cm2)

Ptc = 1750 + 400 = 2150 (kG/m2 )= 0,215 )kG/cm2)

- S tnh ton: ly ra 1 tm vn khun rng 300 di 1,2 m tnh, coi l dm n gin

+ Ti trng tc dng theo chiu rng vn khun (0,3 m) l:

qtt = Ptt(0,3 = 2715x0,3 = 814,5(Kg/m) = 8,15 (Kg/cm)

qtc = Ptc(0,3 = 2150x0,3 = 645 (Kg/m) = 6,45 (Kg/cm)

Tnh khong cch gia cc np ng

+ Dng np ng g c kch thc tit din: b(h = 60x80 cm+ Tnh khong cch gia cc np ng theo iu kin cng :

- iu kin bn ca tm vn khun :

Mmax=( R.W

Trong :

R - cng ca vn khun kim loi R=2100 Kg/cm2W - mmen khng un ca vn khun.vi b rng 300 tra bng ta c W = 6,55 cm3

=> =>

Chn l = 80cm

Vy ta chn khong cch gia cc np ngang l l=80cm. V b tr nh sau:

4. Bin php k thut thi cng i mng, ging mng

a. Cng tc chun b:

- Dn dp mt bng, cng vic thi cng i mng ch tin hnh sau khi tin hnh nghim thu cng tc t.

- Chun b cc phng tin thi cng i mng.

- Kim tra tim i mng v cc mc nh du.

- Kim tra li cao trnh cc u cc c p.

- Phn nh tuyn thi cng i cc.

- Chun b vt liu : xi mng, , ct,si st thp nc m bo s lng v cht lng

- B tr trm trn in nc phi m bo cho qu trnh thi cng, kim tra ng v phng vn chuyn b tng. b. Gic i cc v ph b tng u cc:

b1. Gic i cc:

- Trc khi thi cng phn mng, ngi thi cng phi kt hp vi ngi o c tri v tr cng trnh trong bn v ra hin trng xy dng. Trn bn v thi cng tng mt bng phi c li o c v xc nh y to ca tng hng mc cng trnh. Bn cnh phi ghi r cch xc nh li to , da vo vt chun sn c, da vo mc quc gia hay mc dn xut, cch chuyn mc vo a im xy dng.

- Tri li trn bn v thnh li trn mt bng hin trng v to ca gc nh gic mng.

- Khi gic mng cn dng nhng cc g ng su cch mp o 2 m. Trn cc cc, ng ming g c chiu dy 20 mm, rng 150 mm, di hn kch thc mng phi o 400 mm. ng inh ghi du trc ca mng v hai mp mng; sau ng 2 inh vo hai mp o. Dng c ny c tn l nga nh du trc mng.- Cng dy thp (d = 1mm) ni cc ng mp o. Ly vi bt rc ln dy thp cng mp mng ny lm c o.

b.2. Ph b tng u cc

- Sau khi o h mng xong ta tin hnh p u cc vi chiu di on cc b ph l 0,4m tr ct thp lm neo. Ta s dng cc dng c nh my ph b tng, chong, c...

- Yu cu ca b mt b tng u cc sau khi ph phi c nhm, phi v sinh sch s b mt u cc trc khi b tng i nhm trnh vic khng lin kt gia b tng mi v b tng c.

- Phn u cc sau khi p b phi cao hn ct y i l 10 cm.

c. b tng lt

- Lm sch y h mng sau dng m bn m phng ton b y mng mt ln. B tng lt c khi lng khng ln nn ta c th s dng my trn b tng ti hin trng, vn chuyn b tng xung mng bng xe ci tin v xe ct kt, lp btng lt dy 100 mm.

d. Cng tc ct thp mng.d.1. Yu cu k thut

* Gia cng:

- Ct thp trc khi gia cng v trc khi b tng cn m bo: B mt sch, khng dnh bn t, khng c vy st v cc lp r.

- Ct, un ct thp ng kch thc, chiu di nh trong bn v.

- Vic ct ct thp cn linh hot gim ti a lng thp tha (mu vn...)

- Ct thp cn c ko, un v nn thng.

- Cc thanh thp b bp , b gim tit din do lm sch hoc do cc nguyn nhn khc khng vt qu gii hn ng knh cho php l 2%. Nu vt qu gii hn ny th loi thp c s dng theo din tch tit din cn li.

+ Hn ct thp:

- Lin kt hn thc hin bng cc phng php khc nhau, cc mi hn phi m bo yu cu: B mt nhn, khng chy, khng t qung khng c bt, m bo chiu di v chiu cao ng hn theo thit k.

+ Ni buc ct thp:

- Vic ni buc ct thp: Khng ni cc v tr c ni lc ln.

- Trn 1 mt ct ngang khng qu 25% din tch tng cng ct thp chu lc c ni, (vi thp trn trn) v khng qu 50% i vi thp gai.

- Chiu di ni buc ct thp khng nh hn 250mm vi ct thp chu ko v khng nh hn 200mm ct thp chu nn v c ly theo bng ca quy phm.

- Khi ni buc ct thp vng chu ko phi c un mc (thp trn) v khng cn un mc vi thp gai. Trn cc mi ni buc t nht ti 3 v tr.

* Lp dng :

- Xc nh tim i theo 2 phng. Lc ny trn mt lp BT lt c cc on cc cn nguyn (di 10cm) v nhng ru thp di 40cm sau khi ph v BT u cc.

- Lp dng ct thp trc tip ngay ti v tr i mng. Tri ct thp chu lc chnh theo khong cch thit k (bn trn u cc). Tri ct thp chu lc ph theo khong cch thit k. Dng dy thp buc li thnh li sau lp dng ct thp ch ca i. Ct thp ging c t hp thnh khung theo ng thit k a vo lp dng ti v tr vn khun. Dng cc vin k bng BTCT c gn ru thp buc m bo ng khong cch abv.

- Cc b phn lp dng trc khng gy tr ngi cho b phn lp dng sau, cn c bin php n nh v tr ct thp khng gy bin dng trong qu trnh b tng.

- Theo thit k ta ri lp ct thp di xung trc sau ri tip lp thp pha trn v buc ti cc nt giao nhau ca 2 lp thp. Yu cu l nt buc phi chc khng ct thp b lch khi v tr thit k. Khng c buc b nt.

- Ct thp c k ln cc con k bng b tng mc 100# m bo chiu dy lp bo v. Cc con k ny c t ti cc gc ca mng v gia sao cho khong cch gia cc con k khng ln hn 1m. Chuyn v ca tng thanh thp khi lp dng xong khng c ln hn 1/5 ng knh thanh ln nht v 1/4 ng knh ca chnh thanh y. Sai s i vi ct thp mng khng qu ( 50 mm.

- Thp ch lp dng ct phi c lp vo trc v tnh ton di ch phi > 25d.- Khi c thay i phi bo cho n v thit k v phi c s ng mi thay i.

- Ct thp i cc c thi cng trc tip ngay ti v tr ca i. Cc thanh thp c ct theo ng chiu di thit k, ng chng loi thp. Li thp y i l li thp buc vi nguyn tc ging nh buc ct thp sn :

+ m bo v tr cc thanh.

+ m bo khong cch gia cc thanh.

+ m bo s n nh ca li thp khi b tng.

- Sai lch khi lp dng ct thp ly theo quy phm.

- Vn chuyn v lp dng ct thp cn:

+ Khng lm h hng v bin dng sn phm ct thp.

+ Ct thp khung phn chia thnh b phn nh ph hp phng tin vn chuyn.

* Nghim thu ct thp:

Trc khi tin hnh thi cng b tng phi lm bin bn nghim thu ct thp gm :- Cn b k thut ca n v ch qun trc tip qun l cng trnh (Bn A) - Cn b k thut ca bn trng thu (Bn B).

+ Nhng ni dung c bn cn ca cng tc nghim thu:

- ng knh ct thp, hnh dng, kch thc, mc, v tr, cht lng mi buc, s lng ct thp, khong cch ct thp theo thit k.

- Chiu dy lp BT bo v.

- Phi ghi r ngy gi nghim thu cht lng ct thp, nu cn phi sa cha th tin hnh ngay trc khi BT. Sau tt c cc ban tham gia nghim thu phi k vo bin bn.

- H s nghim thu phi c lu xem xt qu trnh thi cng sau ny.

e. Cng tc vn khun mng.

* Lp dng:

Thi cng lp dng cc tm vn khun kim loi, dng lin kt l cht U v L.

- Tin hnh lp cc tm ny theo hnh dng kt cu mng, ti cc v tr gc dng nhng tm gc ngoi hoc gc trong.

- Tin hnh lp cc thanh chng kim loi.

- Cp pha i cc c lp sn thnh tng mng vng chc theo thit k bn ngoi h mng.

- Dng cn cu, kt hp vi th cng a vn khun ti v tr ca tng i.

- Khi cu lp ch nng h vn khun nh nhng, trnh va chm mnh gy bin dng cho vn khun.

- Cn c vo mc trc c trn mt t, cng dy ly tim v hnh bao chu vi ca tng i.

- C nh cc tm mng vi nhau theo ng v tr thit k bng cc dy chng, neo v cy chng.

- Ti cc v tr thiu ht do m uyn khc nhau th phi chn bng vn g c dy ti thiu l 40 mm.

- Trc khi b tng, mt vn khun phi c qut 1 lp du chng dnh.

- Dng my thu bnh hay my kinh v, thc, dy di kim tra li kch thc, to ca cc i.

- Vn khun v gio khi a vo ch to phi tun th theo TCVN 4453-1995 ( TCVN v kt cu b tng ct thp ton ton khi quy phm thi cng v nghim thu).

- Vn khun, gio phi c thit k v thi cng m bo cng, n nh, d tho lp khng gy kh khn cho vic t c th, v m BT.

- Vn khun phi c ghp kn, kht khng lm mt nc xi mng, bo v cho b tng mi di tc ng ca thi tit.

- Vn khun khi tip xc vi b tng cn c chng dnh.

- Tr chng ca gio phi t vng chc trn nn cng khng b trt v khng b bin dng khi chu ti trng trong qu trnh thi cng.

- Trong qu trnh lp, dng coffa cn cu to 1 s l thch hp pha di khi c ra mt nn nc v rc bn thot ra ngoi

- Khi lp dng vn khun, gio c sai s cho php theo quy phm.* Tho d:

- Vn khun, gio ch c tho d khi b tng t cng cn thit kt cu chu c trng lng bn thn v ti trng thi cng khc. Khi tho d vn khun cn trnh khng gy ng sut t ngt hoc va chm mnh lm h hi n KCBT.

- Cc b phn vn khun gio khng cn chu lc sau khi b tng ng rn c th tho d khi b tng t 50 daN/cm2- i vi vn khun gio chu lc ch c tho d khi b tng t cng quy nh theo quy phm.

f. Cng tc b tng:

* Cng tc chun b.

+Lm nghim thu vn khun, ct thp trc khi b tng.

+ Vi vn khun phi kn kht; nu h t (( 4mm) th ti nc cho g n ra, nu h nhiu (( 5mm) th chn kn bng giy xi mng hoc bng nm tre hay nm g.

+ Ti nc vo vn khun lm cho g n ra bt kn cc khe h v khng ht nc b tng sau ny.

+ Cc vn khun c qut 1 lp chng dnh d dng tho r vn khun v sau.

+ Phi dn dp, lm sch rc bn vn khun.

+ Phi gi chiu dy lp bo v b tng bng cch buc thm cc cc k bng va b tng gia ct thp v vn khun.

+ Trc khi b tng phi kim tra hnh dng v kch thc, v tr, sch v n nh ca vn khun v ct thp.

+ Trong sut qu trnh b tng, phi thng xuyn kim tra vn khun, thanh chng. Tt c nhng sai st, h hng phi c sa cha ngay.

* Cng tc kim tra b tng.

y l khu quan trng v n nh hng trc tip n cht lng kt cu sau ny. Kim tra b tng c tin hnh trc khi thi cng ( kim tra st ca b tng ) v sau khi thi cng ( kim tra cng b tng ).

* K thut b tng.

+B tng thng phm c chuyn n bng t chuyn dng, thng qua my v phu a vo t bm.

+ B tng c t bm vo v tr ca kt cu : My bm phi bm lin tc t u ny n du kia. Khi cn ngng v l do g th c 10 pht li phi bm li trnh b tng lm tc ng.

+ Nu my bm phi ngng trn 2 gi th phi thng ng bng nc. Khng nn ngng trong thi gian qu lu. Khi bm xong phi dng nc bm ra sch.

+ Khi c lp b tng dy 30 cm ta s dng m di m b tng.

+ Chia kt cu thnh nhiu khi theo chiu cao.

+ B tng cn c lin tc thnh nhiu lp c chiu dy bng nhau ph hp vi c trng ca my m s dng theo 1 phng nht nh cho tt c cc lp.

*m b tng.

+ Mc ch:

- m bo cho khi b tng c ng nht.

- m bo cho khi b tng c chc khng b rng hoc r ngoi.

- m bo cho b tng bm cht vo ct thp ton khi b tng ct thp cng chu lc.

+ Phng php m.

- Vi b tng lt mng:

m b tng lt bng my m chn ng mt (m bn), thi gian m mt ch vi m bn l t (30 ( 50) s.

Khi m b tng bng m bn phi ko t t v m bo v tr gii m sau p ln gii m trc mt khong t (5 ( 10) cm.

- Vi b tng mng v ging:

Khi s dng m chn ng trong cn tun theo mt s quy nh sau:

+ m lun lun phi hng vung gc vi mt b tng.

+ B tng lm nhiu lp th m phi cm c 5 ( 10 cm vo lp b tng trc.

+ Chiu dy ca lp b tng m khng vt qu 3/4 chiu di ca m.

+ Khi m xong 1 v tr, di chuyn sang v tr khc phi nh nhng, rt ln hoc tra m xung t t.

+ Khong cch gia hai v tr m l 1,5r0. Vi r0 L bn knh nh hng ca m.

+ Khi m phi trnh lm sai lch vi tr ct thp hoc vn khun.

+ Du hiu chng t m xong l khng thy va st ln r rng, trn mt bng phng.

+ Nu thy nc c ng thnh vng chng t va b tng b phn tng do dm qu lu ti 1 v tr.

* Ch khi dng m rung m b tng cn.

- Ni t vi v m rung .

- Dng dy buc cch in ni t bng phn phi n ng c in ca m.

- Lm sch m rung lau kh v qun dy dn khi ngng lm vic.

- Ngng m rung t 5 n 7 pht sau mi ln lm vic lin tc t 30 n 35 pht.

- Cng nhn vn hnh my phi trang b ng cao su cch in v cc phng tin bo v c nhn khc .

*Bo dng b tng i v ging mng.

- Cn che chn cho b tng i mng khng b nh hng ca mi trng.

- Trn mt b tng sau khi xong cn ph 1 lp gi m nh bo ti, mn ca...

- Thi gian gi m cho b tng i: 7 ngy

Ln u tin ti nc cho b tng l sau 4h khi xong b tng. Hai ngy u c sau 2 ting ng h ti nc mt ln. Nhng ngy sau c 3-10 ting ti nc 1 ln.

+ Khi bo dng ch : Khi b tng cha cng , trnh va chm vo b mt b tng. Vic bo dng b tng tt s m bo cho cht lng b tng ng nh mc thit k v gip cho kt cu lm vic n nh sau ny.

5. T chc thi cng mng

a) Da vo khi lng cng tc,bin php k thut thi cng chn ta chia cng tc b tng phn ngm thnh 3 phn on thun tin cho cng tc thi cng v t chc thi cng.- B tng mng c thi cng lm hai t:

+ t 1 b tng i ging

+ t 2 b tng c ct

b) Ring i vi cng tc vn khun v ct thp do khi lng khng ln, trnh thi gian thi cng lu,nh hng ca thi tit lm chm tin v cn c theo bin ch t i thi cng ta cng tin hnh chia thnh 3 phn on

c. Xc nh khi lng cho tng phn on

KHI LNG B TNG I GING MNG CHO 1 PHN ONSTTCu kinKhi lngS lngTng khi lng(m3)

Phn on1M13,89479,21

M28,262

M429,981

GM11,34

GM21,017

GM30,771

GM51,373

Phn on 2M13,89479,99

M28,262

M37,454

GM11,34

GM40,292

GM51,379

Phn on3M13,89479,14

M28,262

M429,981

GM11,35

GM21,017

GM30,771

GM51,373

KHI LNG VN KHUN 1 PHN ONSTTCu kinKhi lng (m2)S lngTng din tch(m2)

Phn on1M17,084200,6

M211,942

M476,521

GM16,484

GM25,047

GM33,841

GM56,843

Phn on 2M17,084186,72

M211,942

M311,044

GM16,484

GM41,442

GM56,849

Phn on3M17,084213,92

M211,942

M476,521

GM16,485

GM25,047

GM33,841

GM56,843

KHI LNG CT THP CHO 1 PHN ONSTTCu kinKhi lng (Tn)S lngTng khi lng (Tn)

Phn on1M10,3146,24

M20,562

M42,351

GM10,24

GM20,087

GM30,061

GM50,113

Phn on 2M10,3146,11

M20,562

M30,584

GM10,14

GM40,022

GM50,119

Phn on3M10,3146,66

M20,562

M42,351

GM10,25

GM20,087

GM30,061

GM50,113

d. Xc nh thi gian thi cng v nhn cng cho tng phn on

* Tra nh mc 1776 ta c:

- M AF.31125 Btng mng, chiu rng >250cm, btng thng phm bng my bm t hnh nhn cng 1,21 cng/m3, xe bm btng 0,033ca/m3. Trn thc t s lng nhn cng phc v cng tc bm btng bng my th chim khong 25-30% lng nhn cng theo nh mc v ch cn nhn cng m, san mt, vn chuyn ng, sn thao tc(nu c) do lng cng cn thit l 1,21*30% = 0,363cng/m3.

- M AF.61120 Sn xut lp dng ct thp i,ging mng, nhn cng 8,3cng/Tn

- M AF.82111 Vn khun cho b tng ti ch vn khun kim loi, vn khun mng.Nhn cng 38,28 cng/100m2: trong nhn cng sn xut lp dng chim 85%x38,28 =32,538 cng/100m2, tho d vn khun chim 15%x38,28=5,742 cng/100m2

* Tnh chi phi nhn cng cho cc cng vic cho 1 phn on

Phn onTn cu kinM nh mcKhi lngnh mc

Cng/n vNhu cu L

( cng)Tng cng L(cng)

Phn on 1

Lp dng ct thp mng phn on 1AF.611206,24 tn8,3 cng/tn51,7952

Lp dng vn khun thp phn on 1,2,3AF.82111200,6 m232,5 cng/100m265,1965

b tng phn on 1AF.3112579,21 m30,363 cng/m328,7529

Tho vn khun mng phn on 1AF.82111206,6 m25,74 cng/100m211,5412

IV. Bin php k thut thi cng cc cng vic khc ti cos ( 0,000

1. Tnh khi lng cc cng tc

a) Cng tc xy tng mng

Khi lng xy tng t cos -1,05-> - 0.45Tn cu kinKch thc (m)Khi lng (m3)S lngTng khi lng (m3)

Di RngCao

Trc C,D,E44,50,330,68,81326,43

Trc A32,70,330,66,4716,47

Trc B11,10,330,62,2024,40

Trc 1,817,980,330,63,5627,12

Trc 2,720,080,330,63,9827,95

Trc 3,4,5,619,970,330,63,95415,82

Tng khi lng41,76

Khi lng xy tng t cos - 0.45 -> 0.00

Tn cu kinKch thc (m)Khi lng (m3)S lngTng khi lng (m3)

Di RngCao

Trc C,D,E44,50,330,68,81326,43

Trc A32,70,330,454,8614,86

Trc B11,10,330,451,6523,30

Trc 1,817,980,330,452,6725,34

Trc 2,720,080,330,452,9825,96

Trc 3,4,5,619,970,330,452,97411,86

Tng khi lng31,32

b. Cng tc b tng c ct

Khi lng b tng c ctCu kinKch thc (m)Th tch (S)S Tng th tch

DiRng Caom3lngm3

Ct C10,70,31,050,22183,97

Ct C20,70,31,050,22183,97

Ct C30,50,31,050,1660,95

Tng khi lng8,88

c. Cng tc vn khun c ct.

Khi lng vn khun c ct

Cu kinKch thc (m)Din tch (S)S Tng din tch

DiRng Caom2lngm2

Ct C10,70,31,052,11837,8

Ct C20,70,31,052,1851839,33

Ct C30,50,31,051,08366,498

Tng khi lng83,63

d. cng tc lp dng ct thp c ct

khi lng ct thp c ct

Tn vn liuTh tch b tng(m3)Trng lng thp (tn/m3)Hm lng ct thp %Khi lng

(tn)

Thp D250cm, btng thng phm bng my bm t hnh nhn cng 1,21 cng/m3, xe bm btng 0,033ca/m3. Trn thc t s lng nhn cng phc v cng tc bm btng bng my th chim khong 25-30% lng nhn cng theo nh mc v ch cn nhn cng m, san mt, vn chuyn ng, sn thao tc(nu c) do lng cng cn thit l 1,21*30% = 0,363cng/m3.

.- M AF.12230 Btng ct TD ct > 0,1m2, cao