Thuyet Minh Thi Cong 1 - c

CHNG I

AN TT NGHIP TAI : CAO C A CHU PHN THI CNG

CHNG INU PHNG HNG THI CNG TNG QUAT 1.c im cng trnh:

Cng trnh Cao c A Chu s 38-40 Yn Bai - Thanh ph a Nng, co qui m 12 tng va mt tng hm (mt nn tng hm su 0,8m so vi mt t t nhin). Cng trnh c xy dng trn nn t vi cac lp t:

1. Lp 1 : lp t p cua nn nha cu, chiu day 0,5m.

2. Lp 2 : lp t tht ln t cat mn, chiu day 3,5m.

3. Lp 3 : lp cat mn, day 2,5m.

4. Lp 4 : lp t set vi st B = 0,4 day 4m

5. Lp 5 : lp t cat hat trung, chiu day 20m.

Mc nc ngm nm cach mt t t nhin 3m.

c im khu t xy dng: hai bn la hai con hem nho rng khoang 2m phuc vu nhu cu i lai cua ngi dn trong hem, pha sau la sn vn cua nha dn pha trc giap vi ng Yn Bai. Vi nhng c im nay vic la chon phng phap thi cng cac hang muc cng trnh la ht sc quan trong. Vic la chon phng an thi cng c phn tch cu th trong phn sau.

Giai phap kt cu : + Mong: mong coc ai thp.

+ Thn: khung btng ct thep toan khi tai ch.

Cng trnh gn ng giao thng do o thun tin cho vic cung cp nguyn vt liu.

2. Chun b mt bng:

- Cng trnh c xy dng trn nn cng trnh cu tng i bng phng nn cng tac san ui mt bng khng co, ch thc hin don dep v sinh sach se. + Cng tac nh v cng trng: Tt ca cac truc chnh, cao u c truyn dn y u trn mt bng cng trng t h thng li nh v.

- Cp thoat nc: Khi thi cng thng phai dung mt lng nc ln, do vy trong khi thi cng nht thit phai chun b y u cac thit b cp thoat nc. Lng nc sach c ly t mang li cp nc chung cua thanh ph, ngoai ra con khoang mt ging khoang phong mt nc va ly nc phuc vu cho cng tac thi cng cng trnh. Chun b y u cac thit b phuc vu tiu nc (may bm hut nc) cho h ao khi xay ra tri ma nc ngp h ao.

- Thit b in: trn cng trng cac may cng cu ln nh xe cu hu ht dung ng c t trong. in y chu yu phuc vu vao vic chiu sang va cac thit b thi cng co cng sut khng ln lm. Do vy, in c ly t li in cua thanh ph, b tr cac ng dy hp l am bao an toan.3. Thi cng phn ngm:

Theo h s thit k th giai phap mong cua cng trnh la mong coc. Cng trnh xy dng trong thanh ph nn giam ting n va anh hng n cac cng trnh ln cn ta chon phng an mong coc ep. Coc c ep trc khi thi cng ao t nn at c su thit k th phai thc hin ep m.

Do cng trnh co tng hm, mt bng thi cng cht hep nn tranh sat l h ao ta dung c lam tng chen vach t h ao. D tnh ao t bng may n coste mt trn ai coc, sau o ao bng thu cng cho tng ai coc n su thit k.

Btng cho phn ngm: do mt bng cng trnh cht hep va rut ngn thi gian thi cng sm a cng trnh vao phuc vu ta cn ap dung cac tin b ky thut vao trong thi cng, do o btng phn ngm s dung b tng ti thng phm do cng ty san xut b tng cung cp.4. Thi cng phn thn:

Nhm muc ch rut ngn thi gian thi cng, sm a cng trnh vao s dung th btng phuc vu cho phn thn cung s dung btng thng phm. Giai phap thi cng ct, dm san th thi cng ct trc sau o mi n dm san.

Giai phap van khun: qua vic nghin cu th trng va nhng u im, ta chon van khun FUVI.

5. Phng hng t chc va iu hanh:

Cng tac mc bng va xy dng c s ha tng phai c tin hanh trc khi cng tac xy dng chnh am bao a cng trnh s dung ng b:

Vic t chc thi cng phai c tin hanh theo 3 cng oan sau:

- Giai oan chun b.

- Giai oan thi cng chnh.

- Giai oan hoan thin.

B may t chc thi cng phai gon, can b c giao vic phai co chuyn mn phu hp vi tng cng vic c giao

Phi hp cht che gia cac b phn ky thut, lp k hoach cung ng vt t cho cng trng am bao cung cp y u vt t, tin vn theo cung tin thi cng cua cng trnh.

B tr can b quan ly thi cng phu hp vi cng trng.

Chon, b tr th lanh ngh co th am ng cng vic co yu cu ky thut cao.iu ng hp ly cac t i cng nhn co chuyn mn khac nhau trn cng trng, tranh b chng cheo cng vic gy lang ph nhn cng va vt t.6. S b ln danh muc cng vic:

Cng tac mt bng va xy dng c s ha tng phai c tin hanh trc cng trnh xy dng chnh am bao a cng trnh s dung ng b:

Vic t chc thi cng phai c tin hanh theo 3 cng oan sau:

* Giai oan chun b.

* Giai oan thi cng chnh.

* Giai oan hoan thin.

a. Giai oan chun b:

- Cai thin don dep khu t.

- Lam rao tam thi.

- Xy dng cac nha ca tam thi phuc vu thi cng ( ban ch huy cng trnh, kho vt liu, cac xng phu tr, sn, bai xe, lang trai cng nhn, nha n, tram y t, nha v sinh. . . .).

b. Giai oan thi cng chnh:

- Thi cng coc ep.

- Thi cng ong c.

- Thi cng ao t tng hm, h mong bng may ao, vn chuyn t ra khoi cng trng bng xe tai.

- ao h mong bng thu cng.

- Thi cng btng ct thep cho ai coc.

- Thi cng btng ct thep cho dm mong, nn tng hm.

- Thi cng b tng ct thep ct, tng chn, thang may.

- Thi cng btng ct thep hm v sinh, b nc ngm.

- Thi cng b tng ct thep phn dm san, thang b.

- Thi cng xy tng, trat tng.

- Lp t ca khung nhm.

- Thi cng lat gach san cac tng, bc cu thang.

- Thi cng lat gach chng trt, p gach men khu v sinh.

c. Giai oan hoan thin:

- Sn vi cng trnh.

- Lp t lan can cu thang.

- Thi cng chng thm, san nha, tng khu v sinh.

- Lp mang in nc.

- Lp thang may.

- Lp thit b v sinh.

- Lp h thng iu hoa.

- Lp trn.

- Lat gach nn cng trnh.

- Trang tr ni, thi cng ng xa, he ranh cy xanh.

- Nghim thu trc khi ban giao.

CHNG II

BIN PHAP KY THUT VA T CHC THI CNGPHN A: THI CNG PHN NGM

*La chon phng phap thi cng coc:Vic thi cng coc co rt nhiu phng phap a coc n su thit k.

+ Dung lc tnh nen coc.

+ Dung lc xung kch.

+ Dung lc chn ng.

+ Dung lc kt hp: chn ng + xung kch.

+ Ha coc bng phng phap xoi nc...

Do mt bng thi cng cht hep, xung quanh co cng trnh hin hu, cng trnh nm trong long thanh ph. Nn vn thi cng c ra la: khng gy ra ting n; khng gy chn ng anh hng n cng trnh xung quanh. Hn na, do c im mt bng cng trnh hep, nu ao t trc sau o thi cng coc th vic thi cng tr nn kho khn co khi khng thc hin c. Do o phai thi cng coc trc khi ao t, nh vy coc a vao long t su hn mt t t nhin mt khoang. Vi phng an nay th phng phap thi cng coc bng: lc xung kch, lc chn ng hoc kt hp chn ng + xung kch gp kho khn co khi khng thi cng c. Qua nhng phn tch trn ta i n la chon phng phap ha coc bng lc tnh nen coc - ep coc. Vic phn tch u, nhc cua phng phap ep coc c trnh bay phn lp bin phap thi cng ep coc.

I. LP BIN PHAP THI CNG EP COC.

Cng trnh gm 12 ai mong ng vi 4 tn goi: M1, M2, M3 & M4.

M1 (s lng 5 ai): mi ai ong 13 coc dai 16m.




1. u nhc im cua coc ep.

- Coc ep la coc c ha vao trong t tng oan bng kch thuy lc co ng h o ap lc.

- u im: ni bt cua coc ep la thi cng m, khng pha v kt cu nn t, khng gy chn ng i vi cng trnh xung quanh, thch hp cho vic thi cng trong thanh ph, co tin cy, tnh kim tra cao, cht lng cua tng oan coc c th di lc ep, xac nh c lc ep cui cung. Rut ngn thi gian thi cng khi ep su.

- Nhc im: B han ch v kch thc va sc chu tai cua coc, trong mt s trng hp khi t nn tt (set cng..) th rt kho ep coc qua a ti su thit k.

2. La chon phng phap ep coc. Cng ngh thi cng ep coc co hai phng phap :

- Phng phap ep trc: coc c ep trc khi thi cng ai mong.

- Phng phap ep sau: tin hanh ep coc sau khi thi cng ai mong, i vi phng phap nay coc c ep trong qua trnh ln tng, rut ngn c thi gian thi cng. Tuy nhin chiu dai oan coc b han ch bi chiu cao tng. i chiu vi cng trnh: mt bng hep, chiu cao tng hm 3m, chiu dai cua mt coc 16m; ta chon phng phap thi cng coc la phng phap ep trc.

Phng phap ep trc co 2 cach tin hanh :+ Ep coc trc khi ao h mong (phng an 1).

+ Ep coc sau khi a tin hanh ao h mong (phng an 2).

a/ Phng an 1: - Tin hanh ao h mong n cao trnh nh coc sau o a may moc, thit b ep n va tin hanh ep coc n su cn thit.

* u im:

- ao h mong thun li, khng b can tr bi cac u coc nh phng an ep coc trc.

- Khng phai ep coc m.

* Nhc im:

- nhng ni co mach nc ngm cao, vic ao h mong trc, ri mi thi cng ep coc kho thc hin c.

- Khi thi cng ang ep coc gp tri ma, nht thit phai co bin phap bm hut nc ra khoi h mong.

- Vic di chuyn may moc, thit b phuc vu thi cng ep coc gp nhiu kho khn.

- Vi mt bng khng rng rai, xung quanh ang tn tai cac cng trnh, vic thi cng theo phng an nay gp kho khn ln, i khi khng thc hin c.

b/ Phng an 2:

Tin hanh san mt bng cho phng tin di chuyn may ep va vn chuyn coc, sau o tin hanh ep coc theo yu cu thit k. Nh vy at c cao trnh nh coc thit k cn phai ep m. Phai chun b cac oan coc dn bng thep hoc BTCT coc ep c ti chiu su thit k. Sau khi ep coc xong tin hanh ao t h mong thi cng phn ai coc, h ging ai coc.

* u im:

- Vic di chuyn thit b ep coc va cng tac vn chuyn coc co nhiu thun li, k ca khi gp tri ma.

- Khng phu thuc vao mach nc ngm

- Tc thi cng nhanh

* Nhc im:

- Phai dng thm cac oan coc dn ep m, co nhiu kho khn khi ep oan coc cui cung xung chiu su thit k.

- Cng tac ao t h mong kho khn, phai ao thu cng, kho c gii hoa.

- Vic thi cng ai, ging kho khn hn.

Kt lun: Cn c vao u nhc im cua 2 phng an trn, cn c vao mt bng cng trnh cht hep ta chon phng an 2 thi cng la hp l nht ( ep m 1,95 m).

* Giai phap mt bng khi thc hin ep coc:

Mt bng thi cng cua ta cht hep, hai bn co hai con hem nho rng 2m (ch ap ng nhu cu i lai cua dn trong hem bng xe hai banh), bn kia la tng rao nha dn khoang cach t tng rao n nha la tng i gn. Sau lng la sn vn cua nha dn, pha trc la ng Yn Bai. Qua cng tac quan trc, cach cng trnh chng 50m co mt ng thng gia hai hem nay. Khi thi cng ep coc cho day coc ct bin th co hai phng phap t ra:

- Thc hin ep lch: ch cho i trong nm v mt pha khi ep.

+ u im: khng anh hng n s i lai cua dn trong hem, nha bn.

+ Nhc im: thi cng kho khn, yu cu i trong co tai trong rt ln.

- Thc hin ep gia: cho i trong nm v hai pha khi ep.

+ u im: cng tac thi cng n gian, yu cu i trong co tai trong khng ln.

+ Nhc im: anh hng n s i lai cua dn trong hem, do may ep t nh ra hem.

Qua phn tch trn va c s ng y cua chnh quyn, ngi dn trong hem ta chon phng an th hai ep coc. Khi thc hin ep cho day coc bin thuc cac truc1 n 5 th ta m mt ng thng qua hem kia sau cng trnh.

Hnh ve minh hoa:

3. Mt bng nh v bai coc:

S va cu tao mong coc nh hnh ve di y:

MT BNG BAI COC

Da vao cac h truc a c xac nh trn mt bng, ta nh v v tr tm ai coc, v tr tim coc. V tr tim coc trn thc a c anh du bng cac thanh thep (12 dai 0,3m.

4.Chon may ep coc:

- Coc btng ct thep mac 300, co tit din 300x300, ct thep doc 4(20.

- Tng chiu dai coc 2x8 = 16m. Coc chia lam 2 oan mi oan 8m.

- Cao trnh nn t t nhin -2,2m; cao trnh u coc -4,15m.

a/ Xac nh lc ep: s liu tnh toan ly theo h s thit k mong cua cng ty thit k a c kim nghim qua cng tac ep th ngoai hin trng co: (P( =65 tn , Pvl= 150 tn.

- Xac nh lc ep nho nht, tuy thuc vao loai t. y lp di la cat hat trung nn: Pemin > (1,5 ( 2)(P( = 1,5.65 = 97,5 (T)

- Xac nh lc ep ln nht.

Pemax < Pvl\1,25 =150/1,25 = 120 (T)

- Chon Pepmax = 115 (T)

b/ Chon may ep coc:

Cac tiu chun cua may ep phai thoa man:

- Lc nen (danh nh) danh nh cua may phai am bao >1,4Pemax = 1,4.115 = 161 (T).

- Lc nen cua kch phai am bao tac dung doc truc coc.

- Chuyn ng cua pittng phai u va khng ch c tc ep coc.

- ng h o ap lc phai tng xng vi khoang lc o.

- Ch nn huy ng (0,7 ( 0,8) kha nng cua thit b.

5. Tnh toan thit b neo gi:

a/ Chon gia ep coc:

Nhm tit kim chi ph, giam thiu thi gian di chuyn gia ep. Ta chon gia ep coc sao cho tai mt v tr ep c hai day coc nh hnh ve (cho mong bin). L do ta chon gia ep va b tr nh hnh ve la v thc hin phng phap ep gia (u im nu trn) chp nhn phai di chuyn gia ep nhiu ln, nhng bu lai la dung t i trong hn so vi ep lch va phu hp vi vi mt bng cng trnh nho.b/Xac nh i trong ep coc: - Theo iu kin chng nh: QPepmax= 115T

- Theo iu kin chng lt: Mgi 1,15 Mlt

+Tnh toan i trong khi may ep coc bin, tai coc s 1.

Kim tra lt theo phng doc:

S tnh nh hnh ve:

Kim tra lt quanh im B.

(Mgi = P(1,7 + 8,1) = 9,8P

(Mlt =5,8N

Theo iu kin th: 9,8 P ( 1,15.5,8N

( P ( 1,15.5,8N/9,8 = 1,15.5,8.115/9,8 = 78,27 (T)Nh vy trong lng i trong yu cu 2.P = 2.78,27 = 156,54 (T).

Trong lng mt khi i trong BTCT 1 x 1 x 3(m ) : 7,5 (T)

S lng khi i trong yu cu: n = chon 24 khi.

Mi bn t 12 khi, chia lam bn lp, mi lp t 3 khi. t ngang doc cac lp xen ke nhau tao s n nh cho khi i trong khi ep.

Kim tra lt theo phng ngang:

Chon 24 cuc, trong lng cua i trong: Q = 24.7,5 = 180 (T)

S tnh nh hnh ve:

Kim tra lt quanh im C.

(Mgi = Q.1,25= 180.1,25 = 225 (Tm)

1,15(Mlt =1,15.115.1,7 = 224,8 (Tm)

Co (Mgi > 1,15(Mlt nn thoa man iu kin chng lt theo phng ngang.

Vi cac thng s a tnh:

Chon may ep ma hiu:EBT200Co cac thng s k thut sau:

Chiu cao lng ep

: 8,2 (m).

Chiu dai gia ep

: 8(10 (m).

Din tch pittng

: 830 (cm).

Lc ep danh nh

: 200 (T)

6/Chon cn truc phuc vu ep coc:

+Khi cu i trong, gia ep va coc ta chon goc nghing tay cn .Trong lng coc: Qcoc= 1,1.0,3.0,3.8.2,5 =1,98 T

Trong lng cua i trong: Qt= 7,5 T

- Chiu cao nng moc cu yu cu:

Hm=h0+h1+a+h2+h3

Trong o:

h0 chiu cao b.

h1 chiu cao cua khi i trong = 4 m.

h2 chiu dai cu kin =8m.

h3 chiu dai thit b neo buc =1,5m

a khoang cach an toan =0,5m

Hm= 0,7 + 4 + 0,5 + 8 + 1,5

=14,7m.

- Chiu cao tnh n puli nh tay cn:

H = Hm + h4 = 14,7 + 1,5 =16,2m.

Vi:h4 chiu dai thit b puli rong roc =1,5m

Ban knh hoat ng

R = r + Lmin.cos=1,5 + 15,2.=5,43 m

Da vao cac thng s yu cu ta chon cn truc KX5361 L=20m, co Rmin=5,5m.

* Kim tra cac thng s k thut khi cu lp:

+ Cu kin co trong lng ln nht ma may cu phai cu la cuc i trong co trong lng 7,5 tn. Tra trn ng c tnh cn truc KX-5361: vi sc nng 7,5(T) th tm vi ti a cua cn truc la R = 10,5m; chiu cao nng moc cu la (H( = 15,5m - thoa man cac yu cu trn. Nhng trong thc t thi cng do cng trnh vi mt bng hep, ta co th thay i ban knh mi cho thch hp thun tin cho thi cng nhng phai nm trong khoang: 5,5m ( R ( 10,5m.

* Kim tra cn truc khi hoat ng vi vt can la khi i trong:

Kim tra vi iu kin bt li nht ng vi v tr cn truc ap sat may ep coc nht. Ta kim tra khi cn truc vi ban knh vi nho nht co th cu c cu kin la Rmin = 5,5m.

Ta i kim tra bng phng phap th:

T trn th: khoang cach t tay cn n khi i trong e = 1,75m > 1,5m. Vy thoa man iu kin.

( ng vi cac ban knh vi R > Rmin = 5,5m th iu kin nay lun thoa.

c tnh lam vic cn truc KX-5361 (L=20m)

7/Thit k mt bng ep coc va trnh t thi cng: Trong qua trnh ep coc cn truc cu gia ep va i trong di chuyn t mong nay sang mong khac. Con trong mt mong th gia ep se di chuyn trn cac dm ngang va doc ep cac coc cac v tr khac nhau.

Coc c a vao gia ep bng cn truc. thun tin cho thi cng va tit kim chi ph ta chon cn truc lam ca nhim vu cu lp coc va cu lp gia ep, i trong.

Coc c treo buc vao may cu bng cach s dung cap lun qua hai moc cu sn co trn coc.

Vi s di chuyn cua may ep va cn truc nh a thit k, mt bng se ln lt c giai phong trong qua trnh ep am bao cho cac thit b co u mt bng cng tac thi cng an toan.

Trong mt ai coc ep t coc gia trc ri ep ra xung quanh.

+ Thi cng ep cho day coc thuc ct truc B,C trc, sau o mi thc hin ep cho coc thuc ct truc A, D. Chon 4 v tr may cu nh hnh ve thi cng ep coc. Hai day coc thuc hai truc co tnh cht i xng nn trn hnh ta ch ve cho mt bn.

S DI CHUYN MAY EP VA XE CU CHO COC TRUC B,C.

S DI CHUYN MAY EP VA XE CU CHO COC TRUC A, D.8.Tnh toan thit b treo buc phuc vu cng tac ep coc:

* Chon dy cap khi cu i trong:

Chon dy cu 2 dy, goc nghing cua dy cu so vi phng thng ng la 450Trong lng mt khi i trong la: 7,5 T

Chiu dai dy cu: l =

Sc cng dy cu: S =

R ( k.S = 6.5,3 = 31,8 T

Chon cap mm cu truc 6x37x1, ng knh

D = 28,5mm, cng chu keo ( =140kG/cm2, lc lam t cap: 33,75 (T).

* Chon dy cap khi cu khung : S cu coc nh hnh ve:

Chum dy cu 4 dy, goc nghing dy cap 450, khung nm ngang nh puli t cn bng t u chum dy cu.

Trong lng khung : Q = 3,5 (T)

Chiu dai dy cu:

l = m.

Sc cng trong dy cap: S =

Chon cap co R ( k.S = 6.1,24 = 7,44 (T)

Chon cap mm cu truc 6x19x1, ng knh D = 14mm, cng chu keo

( =140kG/cm2, lc lam t cap: 8,62 (T).

* Chon dy cap khi bc xp coc:

S cu coc nh hnh ve:

V tr t hai u coc n im treo buc:

0,21.l = 0,21.8 = 1,68m.

Chon goc nghing nhanh dy so vi phng thng ng ( = 45o.

Sc cng trong dy cap:

= 1,3T

Lc keo t dy cap: R= k(S = 6(1,3= 7,8(T) < 33,75(T) nn ta chon cap nh trn la thoa man yu cu.

* Chon dy cap khi cu coc vao gia ep:

S cu coc nh hnh ve:

V tr treo buc cach u coc oan 0,3l = 0,3.8 = 2,4m.

Sc cng trong dy cap: S=0,3(0,3(8(2,5=1,8(T)

Lc keo t dy cap: R= k(S = 6(1,8= 10,8(T) < 33,75 (T) nn ta chon cap nh trn la thoa man yu cu.

9. Ky thut thi cng :

a.Cng tac chun b:

+Tin hanh kim tra cht lng coc trc khi tin hanh thi cng va loai bo nhng oan coc khng at yu cu ky thut nh: coc co vt nt, truc coc khng thng, mt coc khng phng va vung goc vi truc coc, coc co kch thc khng ung so vi thit k...i vi nhng coc co mt u coc khng phng va khng vung goc vi truc coc th cn phai c x ly trc khi a vao ep.

+Cn chun b ky cac h s sau y:

- H s ky thut v san xut coc.

+ Phiu kim nghim tnh cht c ly cua thep, ximng va ct liu lam coc.

+ Phiu kim nghim xac nh cp phi va tnh cht c ly cua btng.

+ Bin ban kim tra cht lng coc.

- H s ky thut v thit b ep coc.

+ Ly lch may do ni san xut cp va c quan co thm quyn kim tra xac nhn cac c tnh ky thut:

Lng du cua may bm : l/ph

Ap lc bm du ln nht : kG/cm2 Din tch ay pittng cua kch : cm2 Hanh trnh pittng cua kch : cm

+ Phiu kim nh cht lng ng h o ap lc du va cac van chu ap (do c quan co thm quyn cp).

+ Vn ban v cac thng s ky thut cua cng vic ep coc do bn thit k a ra:

Lc ep gii han ti thiu yu cu tac ng ln nh coc Pepmin coc at sc chu tai d tnh.

Lc ep ln nht cho phep tac dung ln nh coc Pepmax nghing cho phep khi ni coc

Khoang chiu dai thit k cua coc

+ Ngi thi cng coc phai hnh dung mt cach ro rang va y u v s phat trin cua lc ep theo chiu su, d oan kha nng xuyn qua cac lp t cua coc. Cho nn trc khi ep phai thm do phat hin d vt, chun b y u cac bao cao a cht cng trnh, biu xuyn tnh, ban b tr mang li coc ...

+Vic b tr coc va i trong phai thoa man nhng iu kin sau y:

Coc khi vn chuyn va b tr trn mt bng phai c k ln cac m g.

Cac m g coc phai nm v tr cach u coc 0,21(l = 0,21(8 = 1,68 m. Nu xp thanh nhiu tng th cung khng cao qua 1,2 m. Luc nay cac m g phai thng hang theo phng thng ng.

- i trong phai c xp chng theo nguyn tc am bao n nh. Tuyt i khng i trong ri trong qua trnh ep coc.

- i trong phai k u khi lng thit k am bao an toan cho thit b ep trong qua trnh ep coc.

b / Xac nh v tr coc:

y la mt cng tac quan trong oi hoi phai c tin hanh mt cach chnh xac v no quyt nh n chnh xac cua cac phn cng trnh sau nay.

Trnh t tin hanh:

Dung cu gm may kinh vy, dy thep nho cng, thc dy va qua doi, ng bot nc hoc may thuy bnh.

T truc nha a c anh du dn v tim cua tng mong, trc tin cn xac nh truc cua hai hang mong theo hai phng vung goc bng may kinh vy, cng dy thep tm giao im hai truc o, t giao im o dung qua doi xac nh tim mong. anh du tim mong bng ct mc co sn o.

T tim mong tm c tin hanh xac nh tim cac coc trong mong o bng may kinh vy, thc dy...,anh du tim coc bng cac coc g thng ng, anh du cao trnh nh coc trn coc mc g bng sn o. c/ Qui trnh ep coc.

Vn chuyn thit b ep coc n cng trng, lp rap thit b vao v tr ep am bao an toan.

Chnh may cac ng truc cua khung may, ng truc kch va ng truc coc thng ng va nm trong mt mt phng, mt phng nay vung goc vi mt phng chun ai mong. Cho phep nghing 0,5%.

Chay th may ep kim tra tnh n nh cua thit b, chay khng tai va co tai.

Dung cn truc cu lp coc u tin (oan C1) vao gia ep coc. Yu cu oan coc u tin phai c dng lp cn thn, cn chnh truc cua oan nay trung vi truc kch va i qua v tr tim coc thit k.

Tin hanh ep oan coc C1. Ban u tng ap lc chm, u oan coc cm su vao t nhe nhang. Vn tc xuyn khng ln hn 1 cm/s.

Tin hanh lp ni va ep cac oan coc tip theo (oan C2).Yu cu i vi oan coc nay la b mt hai u coc phai phng va vung goc vi truc coc. Truc oan coc phai thng (cho phep nghing khng qua 1%).

Gia ln coc mt lc tao tip xuc sao cho ap lc mt tip xuc khoang 3-4 KG/cm2, tin hanh han ni coc.

Tng chm u ap lc ep cho n khi coc chuyn ng (khng qua 1cm/s), n khi coc chuyn ng u tng ap lc nhng khng ch sao cho tc xuyn khng qua 2cm/s.

Khi ep xong oan coc C2, tin hanh cu lp oan coc dn (bng thep) vao gia ep . Tin hanh ep coc gia cho n khi nh oan coc C2 n cao trnh thit k. Nh coc dn ln tin hanh ep coc khac.

Qui trnh ep coc khac tng t nh a trnh bay trn.

Coc c cng nhn ep xong khi thoa man ng thi hai iu kin sau:

- Chiu dai coc c ep su trong long t khng nho hn chiu dai ngn nht a qui nh.

- Tr s lc ep tai thi im cui cung phai at tr s lc ep a qui nh (Pep min < Pep < Pep max ) trn sut chiu su xuyn ln hn 3 ln canh coc (3.0,3 = 0,9m), trong khoang nay tc xuyn khng ln hn 1cm/s.

Nu hai iu kin trn khng am bao phai bao cho chu cng trnh va bn thit k x ly.

d/ Cng tac ghi chep trong nen coc.

Trong qua trnh ep coc phai ghi nht k ep coc theo hng dn di y.

i vi oan coc u tin (C1).

- Khi mui coc a cm su vao t 30 n 50 cm th ghi chep gia tr lc ep u tin.

- Theo doi ng h o ap lc nu gia tr ap lc trn ng h thay i th ghi ngay gia tr nay cung vi su tng ng.

- Nu trong qua trnh ep gia tr lc ep khng thay i hoc thay i khng ang k th ch cn ghi gia tr lc ep u va cui oan coc.

i vi oan coc C2.

- Ghi chep tng t nh oan coc C1.

i vi giai oan cui cung hoan thanh vic ep xong mt coc.

- Khi gia tr lc ep bng 0,8 Pep min th tin hanh ghi gia tr lc ep nay cung vi su tng ng. (Pep min qui nh cn c trn th nghim nen tnh thc t cng trnh).

- Bt u t y ghi chep gia tr lc ep vi xuyn 20 cm cho n khi ep xong.

Mu ghi chep nht k thi cng.

S hiu coc a epNgay, gi ep su ep cocGia tr lc epXac nhn ky thutGhi chu

Ky hiu oan coc su(m)Ap lc (kg/cm2)Lc ep (tn)

Trong o ct ghi chu phai ghi y u cht lng mi ni, ly do va thi gian coc ang ep phai dng lai, thi gian tip tuc ep coc. Khi o cn chu y theo doi chnh xac gia tr lc bt u ep lai.

Nu coc ep at yu cu k thut th ai din cac bn (A,B) phai k vao nht k ep coc.

e / X ly s c khi ep coc.

- Coc nghing qua qui nh (ln hn 1 %) ; coc ep d dang do gp chng ngai vt nh cat hoc li set cng bt thng; coc b v,... nh ln ep lai.

- Khi lc ep va at tr s thit k ma coc khng xung c na, trong khi o lc ep tip tuc tng vt qua tr s lc ep ln nht th trc khi dng ep phai dung van gi lc duy tr Pep max trong khoang thi gian 5 phut.- Khi gp d vt cng bt thng th bao cho n v thit k co bin phap x ly kp thi. f/ An toan lao ng trong cng tac ep coc.

- Tt ca cac k s, k thut vin, cng nhn,... thc hin cng tac ep coc u phai chp hanh nghim chnh ni quy an toan lao ng cua cng trng xy dng.

- Cac khi i trong phai c sp xp tun theo nguyn tc tao thanh khi n nh. Tuyt i khng c i trong nghing, ri trong qua trnh ep.

- Phai tuyt i tun thu cac nguyn tc an toan trong khi vn hanh ; ng c thuy lc, ng c in, cn cu, may han in,...

g/Vn chuyn coc t bai uc coc n mt bng thi cng:

Coc c vn chuyn t ni san xut n sp xp trn mt bng thi cng theo s b tr coc trc khi tin hanh ep coc.

10. Lp tin thi cng ep coc:

Lp tin gi cho cng tac ep coc.

Do mt bng thi cng cht hep va kha nng han ch v may ep nn ta chon giai phap thi cng ep coc mt cach tun t trn toan b mt bng mong. Mi t ep la 1 mong.

-Trnh t ep coc:

+ Bc xp coc vao v tr

+Lp i trong va gia ep

+Lp coc vao khung dn

+Ep coc

+D i trong

a/ Chia phn oan thi cng:

Do mt bng thi cng cht hep nn tin hanh ep coc trn tng phn oan, mi phn oan chia thanh nhiu t, mi t ng vi mt v tr gia ep.

+ Phn oan 1:mong thuc truc: B, C (tr hai mong thuc truc 6).

+ Phn oan 2: mong thuc truc: A, D, 6.b/ Nhp cng tac trn tng phn oan:

-Mi t ep1 khu vc coc, dan c nh, xi lanh di chuyn n cac v tr coc.

-Gia ep co trong lng 6 T, i trong co trong lng 180T chia lam 24 cu kin

-Thi gian bc xp lp dng cac cu kin ly theo chu ky hoat ng cua may khi bc xp cu kiu := (phut)

Trong o:tckc: thi gian cu 1 cu kin

tm: thi gian treo buc cu kin 1phut

hn: cao nng cu kin khoi cao trnh t cu kin 1,5m

hh: cao nng ha cu kin vao v tr tnh t cao hn

i: goc quay tay cn khi bc xp ly 0,5 vong

vn,vh: vn tc nng ha cu kin ly 2m/phut

vq: vn tc quay tay cn 2 vong/phut

tt: thi gian thao dy treo buc 1 phut

to: thi gian k chn cu kin +Thi gian bc xp coc t xe vn chuyn.

cao nng ha cu kin hh=hx+hn= 2+1,5= 3,5m.Vi hx la chiu cao thung xe.

Thi gian k chn cu kin ly to=2phut.

tckc=(phut/cu kin)

+Thi gian bc xp i trong ln gia ep va d i trong ra khoi gia ep.

cao nng, ha i trong ly trung bnh hh= 4m

Thi gian k chn cu kin ly to=3phut

tckc=(phut/cu kin)

+Thi gian cu lp gia ep

Vn tc nng ha cu kin ly vn=vh =1m/phut

cao nng gia ep khoi cao trnh hn, hh= 0,5m

Thi gian k chn iu chnh gia ep ly to=15phut

tckc=(phut)

+ Thi gian cu lp coc vao khung dn

cao nng coc khoi cao trnh hn, hh=10m

Thi gian iu chnh coc vao khung dn ly to=5phut

tckc=phut/cu kin

+Coc BTCT s dung co chiu dai 16m c ct thanh 2 oan 8 m, thi gian ni coc 10 phut.

+Vn tc ep coc trung bnh la : 1,5 cm/s

Hao ph khi ep mt coc (gm hai oan coc dai 8m va oan coc dn dai 1,95m) la: phut

+Thi gian di chuyn xi lanh t v tr coc nay n vi tr coc khac ly 2 phut.

Vic tnh toan tin thi cng cng tac ep coc c th hin bang sau:

PtCac thao tacTng

(gi)

Bc xp

coc

(gi)Bc xp gia ep, i trong

(gi)Lp ni coc

(gi)Ep coc

(gi)Di chuyn xilanh

(gi)D i trong

(gi)

I3,4,5,6,7,8,11,12,13,140,933,62,431,320,133,3

1,9,151,173,63,041,660,163,3

2,10,160,73,61,8210,13,3

Tng14,9157,638,8821,182,0852,8187,45

II1,2,3,4,5,10,11,12,13,14.1,173,63,041,660,163,3

6,90,933,62,431,320,133,3

7,81,43,63,651,990,23,3

Tng16,3650,442,5623,222,2646,2181,0

Tng thi gian ep coc368,45

Tin gi thi cng ep coc c th hin trn ban ve TC-01.II. THI CNG AO T.

*. Chun b:

Trc khi thi cng cng trnh phai tin hanh ban giao ct mc chun gia bn giao thu va bn thi cng. Ct mc chun lam bng b tng t tai v tr khng anh hng n vic thi cng va c rao ky bao v. T ct mc chun, n v thi cng lam nhng coc phu xac nh v tr cng trnh. Nhng coc nay nm ngoai ng i cua xe may va phai c kim tra thng xuyn.

*. La chon phng an ao:

Do cng trnh co tng hm, bin phap thi cng coc ep trc khi ao h mong. V vy, se gp kho khn cho cng tac ao t bng c gii n cao trnh thit k do trong qua trnh ep se xay ra hin tng: mt s coc khng xung c cao trnh thit k se can tr cho vic ao bng c gii. Qua cng tac tnh toan s b lng t cn vn chuyn i khoi cng trng (do cac kt cu ngm: ai mong, ging mong, th tch t ao xy tng hm) ta i n chon phng an ao bng may n cao trnh mt trn ai coc -3,7m , sau o ao thu cng cac h mong ring bit cho n cao trnh thit k -5.0m, chiu su ao thu cng 1,3m bng chiu cao ai mong (1,2m) cng vi lp btng lot ai mong (0,1m). Vi phng an nh trn th lng t cn vn chuyn khoi cng trnh tng ng vi lng t ao bng c gii (tnh toan cu th phn thi cng ao t h mong ). Thao tac ao thu cng, lp t ao thuc loai t tht pha t cat mn nn chon h s mai dc m = 0,25.

Do mt bng cng trnh cht hep, cac ai mong nm sat nhau, chung quanh co cng trnh hin hu, chiu su ao t tng i ln 2,8m (tnh n ay lp btng lot ai mong) nn tranh sut l vach h ao ta chon phng an ong c thep xung quanh h ao chng sat l va giam khi lng ao t.

1. Thi cng ha c thep:

a/ Xac nh s lng, chiu dai va phng phap ha c:

* Xac nh s lng c:

- C c ong cach mep ai coc 0,2m.

- Tng chiu dai ong c : c c ong doc hai bn khu t, mt sau khu t, ring mt trc khu t c ong cha lai mt oan 3,5m gia cha ng ln xung trong thi cng. (lc = 2. 23,75 + 16,6 + (16,6-3,5) = 77,2m

- Chiu rng c thep 0,32(0,45m chon thanh c loai ch U LLL5 co: B = 400; H = 320; d = 14; W = 1256 cm3; I = 20100 cm4.

- S lng c: nc = (lc /0,4 = 77,2/0,4 = 193 (thanh)

* Xac nh chiu dai c chng vach khi ao su 2,8m.

- Lp t th nht (nn nha cu) 0,5m xem nh co tnh cht ging lp th 2.

- Xem c la cng tuyt i ( ch xoay, khng un).

- S ap lc t tac dung ln c:

- Xac nh tai trong tac dung ln c:

+ Ap lc t chu ng tac ng ln 1m tng chn:

Pa = (.H.tg2(450 - ) + q.tg2(450 - ) - C.c (theo l thuyt Coulomb - Sach c hoc t - tac gia Vu Cng Ng, Nguyn Vn Dung).

Trong o: ( = 1,75T/m3: trong lng ring cua t.

( = 250: goc ni ma sat cua t.

q = 1000kG/m2: hoat tai phn b trn nn t.

C == = 1,27

c = 0,07kG/cm2 = 700kG/m2: lc dnh n v

+Ap lc tai mt t:

Po = q.tg2(450 - ) = 1000.tg2(450 - ) = 405,8 (kG/m2)

+Ap lc tai cao trnh ao t H = 2,8m:

PH = 1750.2,8.tg2(450 - ) + 1000.tg2(450 - ) - 1,27.700 =1505,7(kG/m2)

+Xac nh su cua im khng N, tnh t ay h mong bng cng thc:

u = (theo tai liu Thit K Thi Cng- tac gia L Vn Kim- trng ai hoc Bach Khoa TP H Ch Minh).

Vi K = .KP - Ka = .tg2(450 + ) - tg2 (450 - )

Trong o:

- eH: ap lc t tai im ay h mong eH = PH = 1505,7 (kG/m2)

- (g: dung tch cua t (g = 1750 (kG/m3)

- ( = 0,8 h s tra bang phu thuc vao (

- ( =1,3h s an toan v cng

(010152025303540

(0,940,900,860,800,740,670,59

( u = (m)

Tnh tr s QN , MN :

QN = ( Eai; MN =( Eai.ai

- Eai : lc phn b trn 1m dai tng chn:

Ea1 = Po.H = 405,8.2,8 = 1136,3(kG/m).

Ea2 = (kG/m)

Ea3 = PH .u/2 = 1505,7.0,447/2 = 336,5 (kG/m)

- ai: la khoang cach t im t hp lc cua cac lc phn b Eai n im N.

a1 = u + H/2 = 0,447 + 2,8/2 = 1,847 (m)

a2 = u + H/3 = 0,447 + 2,8/3 = 1,380 (m)

a3 = 2u/3 = 2.0,447/3 = 0,298 (m)

QN = ( Eai = Ea1 + Ea2 + Ea3 = 1136,3 + 1539,9 + 336,5 = 3012,7 (kG/m)

MN =( Eai.ai = 1136,3.1,847 + 1539,9.1,38 + 336,5.0,298 = 4324,1(kGm/m)

* Xac nh cm su cua tng c t iu kin n nh:Xem nh c c ngam vao t tai im N, iu kin n nh:

(Mgi ( k(Mlt vi: (Mlt = ( Eai.ai = MN = 4324,1 (kGm)

(

(

( h ( 1,924 (m).

Trong o: h su cua c cm vao long t tnh t im N.

(n = 0,96 T/m3dung trong y ni do lp t nay ngp trong nc.

Vy chiu dai c tnh toan ong xung am bao n nh khi khng dung neo la: L = 2,8 + 0,447 + 1,924 = 5,171. Chon c co chiu dai 5,5m.

* Xac nh kha nng chu lc cua tng c:

Mmen cc ai xut hin trong c tnh cho tm van c rng 0,4m la:

Mmax = 4324,1.0,4 = 1729,64(kGm)

Kha nng chu lc cua tng c:

( = kG/cm2 0,15.9800 = 1470 kG

( Qb > 1470 - 385 = 1085 kG

(a)

va Q0 < 0,5.9800 = 4900 kG

( Qb < 4900 - 385 = 4515 kG

(b)

T (a) va (b), tra S Tay Chon May Thi Cng Xy Dng, chon may ma hiu VPP- 4 co cac thng s ky thut nh sau: P0 = 140kN = 14000kG; n = 1500ln/phut; Qb = 1200 kG, H = 1,5m; L = 1m; B = 0,96m.

c/ Chon cn truc phuc vu thi cng ep c:

S liu phuc vu tnh toan:

+ Chiu dai c thep l =5,5m

+ Chiu cao cua may H = 1,5m

+ Trong lng cua may va c: Q = 1200+385 = 1585kG.

Khi thc hin ep c khng co vt can pha trc nn ta chon goc nghing tay cn (max = 750.- Chiu cao nng moc cu yu cu:

Hm=h1+h2+h3+h4

Trong o:h1 = 0,5m; khoang cach mui c cach mt t khi cu c.

h2 = 5,5m; chiu dai cua c.

h3 = 0,5m; khoang h gia u c va may ong. h4 = 1,5m; chiu cao cua may ong c.

Hm=0,5 + 5,5 + 0,5 +1,5 = 8m.

- Chiu cao tnh n puli nh tay cn:

H = Hm + h5 = 8 + 1,5 = 9,5m.

Vi:h5 chiu dai thit b puli rong roc =1,5m.

Chiu dai tay cn ti thiu:

Ban knh hoat ng nho nht:

R = r + Lmin.cos=1,5 + 8,28.=3,64 m

Da vao cac thng s yu cu ta chon cn truc MKG- 6,3 vi tay cn L = 10m, co ban knh hoat ng 4m < R < 10m.

* Kim tra cac thng s k thut khi cu lp:

Chon ban knh cu lp R = 6m, tra biu c tnh cua cn truc ta c (Q( =3000kG > 1585 kG; (H( = 9m > 8m. Vy thoa man cac thng s trn.

d/ Thi cng ong c thep:

Khi vn chuyn, bc d van c phai cn thn tranh khng b cong vnh, moc ni khng b h hong gy kho khn khi thi cng. Van c c xp ngay ngn, trn cac khuc g m cach nhau 2,5 ( 3m. Trc khi ong, kim tra mep c co tt hay khng, anh du th t van c bng sn. Ha c bng bua chn ng, u van c c khoan l c nh c vao mu di bua chn ng.

ha c, s dung mt cn truc t hanh co 2 puli. Mt puli dung qun dy cap treo bua rung, mt puli dung qun dy cap nng c. u tin, cn truc nng c ln khoi mt t, a c vao ung v tr ep, tc la phai lng tm c a c ep trc, s dung mt cng nhn dung iu chnh c. Sau o cn truc nng bua rung ln, s dung mt s cng nhn iu chnh a bua vao v tr u c. Cui cung la rung bua ha c xung.

Kho khn khi thi cng la trong qua trnh thi cng thng xay ra hin tng xoe nan quat. Cach khc phuc:

+ Ct (vat) u van c v pha trong.

+ Han thm mt ming thep nho vao mep u di c tao lc cn bng vi lc ma sat mep bn kia va t khoi ket vao ranh mep.

+ Ghep mt s van c lai vi nhau ep.

+ Mun cho kht va tt, th ong toan b van c n su 1/3 chiu dai van c, sau o ong tip 1/3 na, vong cui cung ong nt. Nhng nhc im la bua phai di chuyn nhiu.

2. Thi cng ao t h mong:

a/ Tnh toan khi lng cac thanh phn cng tac:

* Khi lng ao t bng c gii:

Hnh dang h ao nh hnh ve:

- Khi lng ao t: VCG = F.h = 23,75.16,6.1,5 = 591,4m3.

MT BNG KHOANG AO, S DI CHUYN

CUA MAY AO VA XE VN CHUYN * Khi lng ao t bng thu cng:

ao cac h mong c lp, vi h s mai dc 0,25. Vy khoang cach t chn h ao n mep h theo phng ngang bng 1,3.0,25 = 0,325m; chon bng 0,35m.

y ta ao bng thu cng nn ta ao cac h mong c lp nhau. V vy ta khng quan tm n khoang cach gia hai mep h ao.

Hnh dang cac h ao nh hnh ve:

Khi lng ao t cac h mong bang sau:

Tn CKKhi lng t ao 1 CK

(m3)S lng CKTng khi lng t ao

(m3)

Mong M133,685168,40

Mong M227,70383,10

Mong M318,83237,66

Mong M411,67223,34

Vy tng khi lng t ao bng thu cng la:

VTC = 168,4 + 83,10 + 37,66 + 23,34 = 312,5 (m3)

* Tnh khi lng t cn vn chuyn khoi cng trnh:

VVC = Khi lng t ao n mt di lp nn tng hm + Khi lng t do kt cu phn ngm chim ch.

+ Khi lng t ao n mt di nn tng hm:

V = 23,55.16,4.1 = 386,2 (m3)

+ Khi lng t do kt cu phn ngm chim ch: ai mong + btng lot ai va dm mong 40x60cm.

Da vao kch thc cua ai, kch thc cua dm mong ta tnh c:

Th tch btng lot ai va ai: V = 178,3 (m3)

Th tch btng dm mong: VK = 33,04 (m3)

Vy khi lng t cn vn chuyn khoi cng trnh la:

VVC = 386.2 + 178,3 + 33,04 = 597,54 (m3)

Khi lng nay tng ng vi khi lng ao bng c gii. V vy, khi lng t ao bng may c vn chuyn ra khoi cng trnh n bai ; con khi lng ao thu cng gi lai phu vu cho vic sang mt bng nn tng hm. Do khi lng t ao bng thu cng tng i ln, lng t nay lai cng trng nn yu cu phai co mt bng t. Mt bng cng trnh cht, nu ta thi cng ao t cho tt ca cac h mong th khng co ch t. V vy, cng tac ao t bng thu cng c chia lam hai giai oan:

+ Giai oan 1: ao h mong thuc truc A, B. Sau khi ao xong tin hanh btng ai coc cho khu vc nay.

+ Giai oan 2: sau khi thao van khun ai mong giai oan 1, ta tin hanh ao h mong truc C, D. Sau khi ao xong tin hanh btng ai coc.

b/ Chon t hp may thi cng ao t:

iu kin t hp la s phu hp v thi gian lam vic cua xe va may. Quan h v s lng va chu k lam vic cua xe va may la:

Chon may ao EO-3322B1 co cac thng s ky thut sau:

Dung tch gu: q = 0,5 m.

Ban knh ao ln nht: R = 7,5 m

Chiu su ao ln nht: H = 4,2m.

Chiu cao t ln nht: H = 4,8 m.

Chu ky ky thut: t

= 17 giy.

H s y gu: k = 1,1 ( t cp II m )

H s quy i v t nguyn th: k = k/k = 1,1/1,2 = 0,92

H s s dung thi gian: k= 0,7.

Tnh nng sut ca may.

+ Khi ao ln xe.

Chu ky ao (goc quay khi t bng 90)

k = 17.1,1.1 = 18,7 giy.

S chu ky ao trong 1 gi n= 3600/18,7 = 192,5.

Nng sut ca cua may ao:

Wca = 7.q.k.n.k = 7.0,5.0,92.192,5.0,7 = 433,9 (m/ca).

S ca cn thit . Chon 1,5 ca. h s thc hin nh mc se la: 1,36/1,5 = 0,91.

Chon xe phi hp vi may vn chuyn t i .

Chon xe Yaz-201E co trong tai P = 10T.

C ly vn chuyn t n bai cach cng trng 5km.

Vn tc trung bnhVtb=25km/h.

Thi gian t tai bai va ng tranh xe trn ng ly td+t0=2+5=7 phut.

Thi gian xe hoat ng c lp.

tx = 2l/vtb + td + t0 = 2.5.60/25 + 7 = 31 phut

Thi gian t y mt chuyn xe.

S gu t y xe:

gu.tb = 13.18,7 = 243,1 giy = 4,05 phut.

Chu k hoat ng cua xe: tckx = 31 + 4,05 = 35,05 phut.

S lng xe cn: Nx = tckx/tckm =35,05/4,05 = 8,65 xe. Chon 9 xe, h s s dung tai trong la: kp = 8,65/9 = 0,96.

S chuyn xe vn chuyn trong 1 ca lam vic:

nch = t.ktg/tckx = 7.60.0,75.0,91/ 35,05 = 8,18 chuyn; ly chn 8 chuyn

Nng sut hoat ng cua xe:

Wcax = nch.P.kp/( = 8.10.0,96/1,75 = 43,9 m3/ca.

Thi gian mt xe vn chuyn ht lng t trn:

t = 591,4/(9.43,9) = 1,496 ca. Ly tron 1,5 ca

Kim tra thy thi gian ao bng may bng thi gian t cua xe nn thoa man.

Vy ta chon t hp: 1 may ao EO-3322B1 va 9 xe vn chuyn Yaz-201E. Tnh s cng nhn ao t :

Theo nh mc XDCB-1242 (do kch thc h ao ln, su nng nn co th tra nh mc theo ao t p) ma hiu BA-120 th ao 1m3 t cp 2 cn 0,62 cng .

Vy s cng ao t thu cng la : 0,62.312,5 = 193 cng.III. THI CNG AI MONG COC:

1.Cng tac chun b:

- Sau khi hoan tt cng tac ao t h mong, ta i xac nh lai cao cua ay mong v tr ct ngam vao ai.

Tin hanh p u coc t trn xung, khi oan coc con lai khoang 250mm th ta lam phng u coc. oan coc 250mm gm 100mm nm trong lp btng lot, 150mm c ngam vao ai coc.

Tin hanh tao phng, v sinh ay h mong, chun b lp btng lot.

2. btng lot:

Dung btng lot a 4x6 mac 75 day 100mm.

Khi lng btng lot cho tng cu kin:

Tn CKKhi lng btng 1 CK

(m3)S lng CKTng khi lng btng

(m3)

Mong M11,59457,97

Mong M21,43234,296

Mong M30,84521,69

Mong M40,40320,806

Vy tng khi lng btng cn dung: V = 14,76 (m3)

3.Ct pha mong:

Ct pha s dung trong an la ct pha FUVI, tm ct pha c ch tao bng nha, cac thanh ngang, doc c lam bng thep rng. Nhng c tnh, thng s k thut cung nh cac qui nh khi s dung tm ct pha nay c trnh bay phn thi cng phn thn.

a/ Tnh toan ct pha:

Theo qui nh, khi lp rap van khun ng chu tai trong ngang phai t cac thanh ngang tai v tr tip giap cua cac tm ct pha, vi khoang cach bng b rng cua tm ct pha.Tt ca cac tm van khun c lin kt vao nhng thanh nep ngang co tac dung nh gng. Cac thanh nep ngang nay c lin kt vao nhng thanh nep ng ly h van khun mong va gi no n nh. ai mong cao 1,2m nn s dung tm ct pha co kch thc 300x1000x50, cac thanh ngang cach nhau 0,3m.

Do cac mong co kch thc khac nhau nn ta i kim tra s lam vic cua h van khun cho ai mong co tit din ln nht la mong M1.* Xac nh tai trong

+ Ap lc cua va btng mi tac dung vao cac thanh van khun:

Bin phap m la m trong, vi ban knh tac dung R = 0,75m

Chiu cao lp btng H = 1,2m > R

( P = ((R = 2500.0,75 = 1875 KG/m2.

+ Tai trong do chn ng phat sinh khi btng bng bm: P = 200KG/m2.

+ Tai trong do m va btng tnh bng 200 KG/m2 b mt cua van khun.

( Cac tai trong nay ly theo tai liu Van Khun Va Gian Dao -Tac gia Phan Hung - Trn Nh nh - Nha Xut Ban Xy Dng).

Tuy nhin tai trong nay ch tnh khi khng tnh tai trong chn ng.

( Tng tai trong ngang tac dung vao thanh van khun:

Ptc = 1875 + 200 = 2075 G/m2

Ptt = 1,1.1875 + 1,4.200 = 2342,5 KG/m2(1,1 va n = 1,4 la h s vt tai do trong lng cua btng va chn ng khi ).* Tnh toan khoang cach cac thanh chng ng:

Xem thanh ngang la dm lin tuc gi ln cac thanh chng ng, chu tai trong phn b u, tnh cho thanh ngang di cung chu tai trong ln nht.

S tnh:

Tai trong phn b qui v 1m dai tac dung ln sn ngang:

qtc = 2075.0,3 = 622,5 KG/m

qtt = 2342,5.0,3 = 702,8 KG/m

Tnh khoang cach gia cac thanh chng theo cng thc sau :

+ Theo iu kin cng : < RkCT3 = 2100 KG/cm2

Vi M la moment ln nht tai cac gi ta : M

Chon thanh ngang co tit din vung co BxHxd = 50x50x1,5 mm co moment chng un W va moment quan tnh J tnh nh sau :

J cm4 cm3Thay M va W vao cng thc trn co :

lcm.

+ Theo iu kin vong :

cm.Chon khoang cach cac thanh chng ng tuy thuc vao chiu dai tm van khun va thoa man l < 116,8cm. Ta chon khoang cach thanh chng ng ln nht la 1m.

* Tnh toan kha nng chu lc cua cac thanh chng ng :Thanh nep ng chu cac lc tp trung t cac a ngang truyn vao di dang tp trung. hai u thanh chng ng c bt bu lng lin kt vi cac cac thanh chng hoc dy cng.Ta xem nh thanh chng ng lam vic nh 1 dm n gian chu lc tp trung vi nhp tnh toan la chiu cao ai mong.

Lc tp trung P: ptc = qtc.l = 622,5.1 = 622,5 KG

ptt = qtt.l = 702,8.1 = 702,8 KG

Vic tnh toan ni lc cua thanh chu lc phn b la phc tap. n gian ta qui lc tp trung v tai trong phn b u: qtc = ptc/l1 = 622,5/0,3 = 2075 KG/m

qtt = ptt/l1 = 702,8/0,3 = 2342,5 KG/m

S tnh la:


M = Mmax = qttl2/8 = 2342,5.1,22/8 = 421,65 KGm

Wyc = Mmax/R = 421,65.102/2100 = 20,1 cm3Chon thanh ng la thep ng tit din vung co BxHxd = 100x50x5mm co W = 34,73cm3, J = 173,67 cm4.

+ Kim tra theo iu kin vong :

f =

am bao iu kin vong.b/ Trnh t lp dng va thao ct pha mong:

+ Trnh t lp ct pha ai:

Ly du chu vi ai mong.

Lin kt cac ct pha nh hnh vi nhau va tm ct pha vi thep hp.

- Lp ghep cac tm ct pha bao quanh 3 mt cua ai mong c nh chc chn bng h chng thanh ct pha.

Tin hanh lp t ct thep.

Lp t ct pha thanh ai con lai.

Kim tra thng ng cua van khun.

Kim tra, sa cha va hoan chnh ln cui cung trc khi btng.

+ Trnh t thao d van khun: tin hanh ngc lai cac giai oan trn.

4. Thi cng ct thep mong:

Cng tac ct thep c tin hanh sau khi a lp t xong van khun ai coc.

Ct thep c gia cng xng thep tai cng trnh theo ung qui cach va chung loai a thit k. Sau o c ct lai thanh tng bo, anh s hiu theo tng cu kin tin cho thi cng va khng b nhm.

u tin cho thi cng ct thep ai coc. Thep ai coc c t trn cac u coc, tai cac v tr khng co u coc ta k bng cac chn thep t ln mt btng lot.

Sau khi t xong ct thep ai coc, ta kim tra lai v tr tim ct mt ln na ri cho t thep ch cua ct.

5. Thi cng btng mong:

c tin hanh khi a nghim thu xong van khun va ct thep ai coc. Do qua trnh ao t cac h mong chia lam hai khu vc nn qua trnh btng cung chia lam hai khu vc thi cng tng ng vi hai khu vc ao t: khu vc 1 la ai mong thuc truc A, B; khu vc 2 la ai mong thuc truc C, D. y ta i t chc thi cng cho khu vc1. Khu vc th hai co khi lng tng ng khu vc 1 nn qua trnh t chc thi cng ging khu vc mt.

Trong khu vc 1 ta chia ra lam 5 phn oan thi cng.

* Bin phap thi cng:

V lng btng kha ln nn ta dung btng c bm trc tip t xe btng vao cac h mong thng qua tram bm.

Btng c day tng lp khoang 30cm. Cng nhn ng trn san cng tac tha m dui xung va m btng.

Du hiu chng to m xong la khng thy va btng sut lun ro rang, trn mt bng phng va co nc btng ni ln.

Khi rut dm qua v tr khac phai rut t t va khng nn tt ng c tranh lai l rng trong btng a m.

Mi bc cua m khng nn vt qua 1,5 ln ban knh anh hng cua m.

6. T chc thi cng ai mong:

a/ Phn oan thi cng:

Chia nh hnh ve:

Vic tnh toan khi lng cng tac cua tng loai mong va mi phn oan c tnh toan kt qua ghi trong bang sau:

Khi lng cng tacKch thc(m)

(LxBxh)Btng

(m3)Ct thep

(tn)Van khun

(m2)

Mong M16,03x2,4x1,217,3671,04220,232

Mong M25,63x2,4x1,216,2150,97319,272

Mong M35,35x1,45x1,29,3090,55816,32

Mong M42,4x1,45x1,24,1760,259,24

Phn oan 113,4850,80825,56

Phn oan 2, 3,417,3671,04220,232

Phn oan 516,2150,97319,272

(Ham lng ct thep cho 1m3 btng mong: 60 kG)b/ Tnh nhp cng tac cac dy chuyn b phn:

Chon t th chuyn nghip:

T thTng Bc thGhi chu

2345

Ct thep622111t

Van khun 61321t

Btng 1043211t

Thao van khun31111t

Chi ph lao ng cac cng vic ly theo nh mc 1242:

Gia cng lp dng ct thep:6,35 cng/tn (ma hiu IA.1130)

- Gia cng lp dng thao d van khun mong (ly theo van khun kim loai): 38,28cng /100m2 (ma hiu KB.2110).

Btng mong: 0,63 cng/m3 (ma hiu HC.1210).

nh mc chi ph cng cho van khun nha khng co nn y ta ly nh mc chi ph nhn cng theo van khun thep.

nh mc chi ph nhn cng cho cng tac van khun bao gm san xut lp dng, thao d. phn chia chi ph lao ng cho cac cng vic thanh phn da vao c cu chi ph theo nh mc 726, ma hiu 5.007.

San xut: 0,8gc/cm2 (5.007a)

Lp dng: 1,00gc/cm2 (5.007d)

Thao d: 0,4gc/cm2 (5.007e)

T l chi ph la:

San xut, lp dng: ( Thao d: (Vy: Chi ph san xut, lp dng: 38,28.81,8( = 31,31cng/100m2 Chi ph thao d: 38,28.18,2( = 6,96cng/100m2

Nhp cng tac cua dy chuyn: kij = (ngay)

Chon h s ca lam vic nc = 1.

Tin hanh tnh toan va chon lai nhp cng tac cua cac dy chuyn b phn nh sau:

DC

PCt thepVan khunBtngThao van khun

Tnh toanChon(Tnh toanChon(Tnh toanChon(Tnh toanChon(

10,8610,861,331,50,890,8510,850,590,51,18

2,3,41,111,11,0511,051,0911,090,470,50,94

51,0311,031111,0211,020,450,50,9

H s thc hin nh mc trn toan b cac phn oan:

t ct thep: (1 =

Lp dng van khun: (2 =

btng: (3 =

Thao van khun: (4 =

c/Tnh thi gian dy chuyn ky thut:Gian oan cng ngh gia btng va thao d van khun: t = 2 ngay.

+ Gian cach gia dy chuyn ct thep va lp van khun vao phn oan 1:

O11 = 1 ngay.

+ Gian cach gia dy chuyn lp van khun va btng vao phn oan 1:

O21 = 1,5 ngay.

+ Gian cach gia dy chuyn btng va thao van khun vao phn oan 1:

O11 = 3+2 = 5 ngay.

Bang tnh ghep ni cac dy chuyn b phn:

DC1234tjSj

P

1012.57.5

11.514 0.544

12.53.58

212.53.58

10.5 114 0.53.54

23.54.58.5

323.54.58.5

10.5 113 0.53.53.5

34.55.59

434.55.59

10.5 112.5 0.53.53.5

45.56.59.5

545.56.59.5

10.5 112 0.53.52.5

56.57.510

Ti55.552.518/17.5

th tin :

DC1: lp t ct thep. - DC 3: btng mong.

DC 2: lp t van khun - DC 4: thao d van khun.

Thi gian thc hin dy chuyn btng mong khu vc I la: T = 10ngay.

H s s dung thi gian cua phng an: k = 18/ (18+17,5) = 0,507.

IV. THI CNG DM MONG, C MONG:

Dm mong co kch thc 400x600 c th hin trn hnh ve sau:

Sau khi hoan thanh cng tac btng ai mong va lp t xung quanh ai coc ta tin hanh btng dm mong va c ct. Btng s dung la btng ti thng phm do cng ty san xut btng cung cp. Btng dm mong c ng thi vi c ct n cach coste nn tng hm 0,1m.

Tng khi lng btng dung la: V = V1 + V2Vi V1 la btng c ct.

Cu kinC1C2C3C4C5

BxLxh (m)0,7x0,7x0,60,7x0,7x0,60,5x0,5x0,60,4x0,7x0,60,5x0,5x0,6

K/lng 1CK(m3)0,2940,2940,150,1680,15

S lng CK44284

Tng K/lng(m3)1,1761,1760,31,3440,6

Vi V2 la btng dm mong: V2 = 28,44m3.

Vy khi lng btng cn thit la: V = 4,596 + 28,44 = 33,036m3.

Lng ct thep cn thit: 33,036.150 = 4955,4kG

(Ly ham lng ct thep 150kG/1m3)

Din tch van khun cn thit: 167,4m2.

Khi lng btng lot dm mong: bxhxl = 0,5.0.1.72,26 = 3,613m3.

V. THI CNG NN TNG HM.

1. Ky thut thi cng:

Nn tng hm gm lp btng lot a 4x6 mac 100 day 100, san btng ct thep mac 300 day 100. Sau khi lp t va m cht n cao ay tng hm, ta thi cng lp btng lot trt. Sau o tin hanh t ct thep, thep c k ln cac thanh chng thep cao 3m. Khoang cach cac thanh thep c anh c anh du bng mc trn lp btng lot va anh du phn trn cy thep.

2. T chc thi cng:

a/ Xac nh c cu qua trnh:

Qua trnh thi cng san tng hm gm cac qua trnh thanh phn sau:

btng lot san tng hm.

t ct thep.

btng va bao dng.

b/ Tnh nhp cng tac cho cac qua trnh:

Khi lng thi cng san:

- Lp btng lot co khi lng bng lp btng san tr i phn th tch dm mong va c mong chim ch co khi lng: 18,2 m3.

Khi lng btng san: 23,7m3 Khi lng thep: 0,711 (T)

( Ly ham lng ct thep cho 1m3 la 30kG)

Chi ph lao ng ly theo inh mc 1242.

Btng lot mong (ma hiu HA.1120): 1,18 cng/m3 Ct thep (ma hiu IA.2511): 14,63 cng/tn.

Btng nn (ma hiu HC.1310): 0,58 cng/m3.

Chi ph cng tac:

Cng tacn vKhi lngnh mcCng

btng lotm318,2HA.112021.48

t ct theptn0.711IA.251110.4

btngm323.7HB.131013.75

Tng cng45.63

VI. THI CNG TNG TNG HM.

1. Trnh t thi cng:

t ct pha cho mt sat thanh h, sau o t ct thep va cui cung dng ct pha cho mt con lai. ct pha ng vng va chu c tai trong ngang cua btng ti th ta phai dung cac thanh chng .

Chiu cao cua tng chn 3m nn ta dung tm ct pha co kch thc 300x1000x50 ghep lai thanh mang tng. Cac tm ct pha nay t ng va c bi cac thanh ng dang thep hp rng t tai v tr tip giap cua cac tm ct pha, cac thanh ng lai gi ln cac thanh ngang c nh v bng cac thanh xin va ngang.

2. Tnh toan van khun:

Khi tnh toan van khun tng, thin v an toan ta ly ap lc va btng tac dung ln van khun trn sut chiu cao bng ap lc va btng tai ay tng. * Tai trong ngang tac dung ln thanh van khun: tng t van khun ai mong, tng tai trong ngang tac dung ln thanh van khun tng:

Ptc = 2075 kG/m2

Ptt = 2342,5 kG/m2a. Tnh thanh ng:

Xem thanh ng la dm lin tuc chu tai trong phn b u ma gi ta la cac thanh ngang, chon khoang cach gi cac thanh ngang 1m.

S tnh:

Tai trong phn b trn 1m dai tac dung ln thanh ng:

qtc = 2075.0,3 = 622,5 kG/m

qtt = 2342,5.0,3 = 702,8 KG/m

(Khoang cach gia cac thanh ng la 0,3m)

+ Theo iu kin cng :

Mmax = qtt.l2/10 = 702,8.12/10 = 70,28 kGm

Wyc =

Chon thep thanh lam thanh ng la thep ng tit din vung co

BxHxd = 50x50x1,5mm co W = 4,568 cm3, J = 11,419 cm4.

+ Kim tra vong:

am bao iu kin vong.

b. Tnh thanh ngang:

Tnh thanh ngang nh dm lin tuc chu tai trong tp trung do cac thanh ng truyn vao co gi ta la tai v tr ty xuyn lin kt gia hai tm ct pha trong va ngoai cua tng chn. Chon khoang cach gia hai ty xuyn la 0,9m.

S tnh :

Lc tp trung P: Ptc = qtc.l = 622,5.1 = 622,5 kG

Ptt = qtt.l = 702,8.1 = 702,8 kG

tin cho tnh toan ta qui tai trong tp trung v phn b u.

qtc = Ptc/ 0,3 = 622,5/ 0,3 = 2075 kG/m

qtt = Ptt / 0,3 = 702,8/ 0,3 = 2342,5 kG/m

+ Theo iu kin cng :

Mmax = qtt.l2/ 10 = 2342,5.0,92/ 10 = 189,74 kGm

Wyc = cm3.

Chon thanh ngang la 2 thanh thep hp tit din vung ghep sat nhau co kch thc BxHxd = 50x50x1,5 co W = 9,136 cm3, J = 22,838 cm4.

+ Theo iu kin vong:

am bao iu kin vong.

3. T chc thi cng:

Btng tng thi cng lin khi vi ct bin cua tng hm va c t chc thi cng trong thi cng phn thn cng trnh c trnh bay trong phn sau.

PHN B: THI CNG PHN THN

Chng 1: GII THIU COPPHA FUVII. Li ch khi s dung:

Ct pha FUVI san xut bng nguyn liu va phu gia t bit vi dy chuyn san xut hin ai bc nht th gii. Nhng li ch to ln mang lai khi s dung ct pha FUVI trong qua trnh thi cng xy dng cng trnh nh sau:

1. S ln s dung rt cao: ct pha FUVI co bn rt cao, chu c va p va anh nng mt tri. S ln s dung thc t vt qua 100 ln.2. chnh xac cao: kch thc va vung goc cua tng tm ct pha rt chnh xac. iu o thun li cho lp rap va giam thi gian thi cng.3. a dang kch thc: ct pha FUVI co nhiu kch thc tiu chun khac nhau tao thanh t hp din tch va vi kch thc mong mun nn khng tn thi gian va cng sc lot dm g.4. Kinh t: do s dung nhiu ln, lp t nhanh thm vao o b mt san, ct co th khng cn trat va nn gia thanh cho mt ln s dung ha n mc khng cn ang k.5. Tng cht lng b mt san, ct: do ct pha FUVI lam bng plastic khng thm nc va r st, cht lng b mt btng lam ban hai long hn bao gi ht.

6. Nhe, an toan: so vi ct pha lam bng st, ct pha FUVI an toan cho cng nhn, t bit la khi thao tac cao ln. Ct pha FUVI khng ct tay va va cham nguy him cho cng nhn. Cht nha thay cho inh st cung la mt yu t an toan khi s dung ct pha FUVI.

7. a nng: ngoai chc nng chnh la lam ct pha, co th s dung lam paralet k lot chng thm cho ximng hay cac vt liu xy dng khac mt cach l tng.

8. Vn con mang li ch sau 3 nm s dung: sau 3 nm s dung, vic thanh l san phm khng nhng v cung thun li so vi ct pha st va g ma con co th thu hi mt khoang kinh ph ang k.

Tm van khun a nng:

II. Cac qui nh khi s dung:

1. san:

- u tm ct pha phai trn a.

- Khoang cach gia hai a bng 500mm.

- u tm ct pha khng ta ln a se b sup xung khi co tai trong cua btng.

- Khoang cach gia hai a ln hn 500mm se lam tng vong qui nh cua tm ct pha. Do o khoang cach a cn c kim tra phai ung bng 500mm.

2. tng:

- Tm ct pha t thng ng.

+ Trng hp 1: nu dung thanh doc, t ngay tai canh tip giap cua cac tm ct pha: khoang cach bng ung chiu rng cua tm ct pha.

+Trng hp 2: nu dung thanh ngang ,c canh nhau khng qua 0,25m.

tao mang ct pha s dung cac tm ct pha a nng vi cac kiu lp ghep tao t hp tm, tao goc trong, goc ngoai, lin kt tm ct pha vi xng thep hp, lin kt xng vi nhau .

Hai mang ct pha tng c ging vi nhau bng h thng cac thanh xuyn tuy thuc vao kch thc kt cu tng.

Ct pha tng c nh v bng cy chng thep hoc thep tron dy cap vi tng .

3. ct:

Tuy theo kch thc, phng an b tng thu cng hay bm, bc gng L se chon t 0,5n 1m

Ct pha ct s dung cac kiu lp ghep tao goc ngoai vi tm ni goc ngoai va dung cach p mt m.

dng ct s dung cy chng g hoc chng thep vao b gng ct. S dung dy cap va tng nh v ct.

4. dm:

Vi dm c nho, dm cht tam giac lin kt tm ct pha vi tm ct pha ay dm.

Vi dm c ln, dung tm ni goc ngoai tao goc ngoai cho van khun dm.

Chng 2: THIT K VAN KHUN PHN THNS liu thit k:

- Chiu cao tng: + Hm: 3m

+ Trt: 3,5m

+ Cac tng con lai co chiu cao 3,3m.

- Kch thc tit din ct (xem hnh ve mt bng ep coc chng 1).

Tn ct

TngTit din

C1C2C3C4C5

Hm n tng 4700x700700x700500x500400x700500x500

Tng 5 n 7600x600600x600500x500400x700400x400

Tng 8 600x600500x500500x500400x700400x400

Tng 9 n 10500x500500x500500x500400x700400x400

Tng 11500x500500x500500x500400x400400x400

- Kch thc tit din dm:

+ Dm ngang nha: 300x500 mm.

+ Dm doc nha: 300x500; 300x700 mm.

+ Dm bo: 200x400 mm.

I. Tnh van khun, xa g, ct chng san:

Cng trnh Cao c A Chu gm 12 tng va mt tng hm, kch thc cac san mi tng tng i ging nhau. Chiu cao tng trt la 3,5m (cac tng con lai cao 3,3m) nn ta chon tng 1 tnh s dung ct chng xa g. Tai v tr thng tng th ct chng van khun san tng 2 t ln san tng trt vi khoang cach hai tng 6,8m, nn s dung h giao PAL cua cng ty Hoa Phat.

Cac san c phn chia bi cac h thng dm phu va chnh. Cac san co cac kch thc ln nho khac nhau ma ta khng th s dung lun 1 tm van khun cu tao ma la s dung t hp cac van khun theo kch thc cua cu kin ( dai ( rng = 1000(A) vi A la kch thc con lai cua ban o. Sau y la bang t hp thng s dung :

A

Loai 4004505005506006507007508008509009501000

1000x200211221122

1000x250111111

1000x3001121122312

lin kt lai vi nhau bng cac cht ch I, L, T va c gac lin cac xa g ngang, cac xa g nay c bi cac xa g doc. Vic lp ghep cac tm ct pha phai tun thu ung yu cu cua nha san xut. Do o ni dung tnh toan bao gm cac bc sau y:

+ Chon tit din xa g, tnh va kim tra kha nng chu lc theo iu kin cng va vong.

+ Tnh toan, kim tra ct chng (giao PAL).

Do trong mt san co nhiu san co kch thc khac nhau, tin ta i tnh toan cho mt vai san in hnh bt li nht sau o t cho cac san con lai.

1.Trng hp san 4,5 x 4,5 m:

Tai trong tac dung ln san:

Trong lng cua san btng ct thep day 100mm: 0,1.2600 = 260 kG/m2.

- Hoat tai thi cng: 250kG/m2 - tai liu Van Khun Gian Giao- tac gia Phan Hung va Trn Nh nh.

- Tai trong do trong lng ban thn cua van khun la rt nho nn trong tnh toan co th bo qua.

Tai trong tiu chun tac dung ln san: qtc = 260 + 250 = 510 kG/m2.

Tai trong tnh toan tac dung ln san: qtt = 260.1,1 + 250.1,4 = 636kG/m2.

a/ Tnh xa g ngang:

Chon thanh thep lam xa g ngang la thep ng co tit din BxHxd = 50x50x1,5mm co: W = 4,568cm3, J = 11,419cm4.

S tnh xa g ngang la dm lin tuc chu tai trong phn b u do tm ct pha san truyn xung vi gi ta la cac xa g doc, khoang cach theo qui nh cua cac xa g ngang la 0,5m.

Tai trong tac dung ln xa g ngang :(bo qua trong lng ban thn xa g v qua nho).

qtc = 510.0,5 = 255kG/m

qtt = 636.0,5 = 318kG/m

S tnh:



Thay vao cng thc trn co :

lcm.

+ Theo iu kin vong:

cm.

Vy chon khoang cach gia hai xa g doc Ptt = 915,9.4 = 3663,6kG. am bao u khng nng chu lc.

2. Trng hp san co b rng thay i theo chiu cong cua dm bo:

san co canh cong theo dm bo nn khi s dung tm van khun nha a nng lp th ta phai co bin phap lp nhng khoang h con lai do tm khun la nhng tm khun co canh vung goc. y, ta lp van khun nha ra1m, phn con lai dung van khun g lam van san.

a/ Tnh van san:

Chon g van san day 3cm, chiu dai tm van san c theo phng canh ngn cua san. S lam vic cua van san la dm n gian k ln cac gi ta la xa g.

Tai trong tac dung ln van san (ct ra mt day san theo phng canh ngn).

Trong lngbtng ct thep: 2600.0,1.1 = 260 kG/m.

Trong lng van g: 0,03.600.1 = 18 kG/m.

Hoat tai thi cng: 250.1 = 250 kG/m.

( qtc = 260 + 18 + 250 = 528 kG/m.

qtt = (260 + 18).1,1 + 250.1,4 = 655,8 kG/m.

Tnh khoang cach xa g theo kha nng chu lc cua vt liu:

+ Theo iu kin cng :

( = = 150kG/cm2. vi M = qtt.l2/ 8; W = b.h2/ 6

( l ( cm.

+ Theo iu kin vong:

( =

Chon khoang cach ln nht gia hai xa g la: 90cm.

b/ Tnh xa g san:

Chon xa g lam bng thep hp co kch thc BxHxd = 40x80x1,5mm; co W = 7,475cm3, J = 29,902cm4.

Tai trong tac dung ln xa g ( trong lng xa g thep rt nho nn co th bo qua).

qtc = 0,9.528 = 475,2 kG/m

qtt = 0,9.655,8 = 590,22 kG/m

S tnh xa g la dm lin tuc k ln cac gi ta la ct chng.

Tnh khoang cach ct chng :

+ Theo iu kin cng :

( = = 2100kG/cm2. vi M = qtt.l2/ 10; W = b.h2/ 6

( l ( cm.

+ Theo iu kin vong:

( =

Chon khoang cach ln nht gia hai ct ( 161,7cm. Ta chon khoang cach ln nht la: 150cm.

c/ Tnh ct chng:

Tai trong tac dung ln ct chng: Ptt = qtt.l = 590,22.1,5 = 885,33kG < 915,9kG (lc ct chng xa g san phai chu).

Chiu cao cn thit cua ct: h = 3,3 - 0,1 - 0,03 - 0,08 = 3,09m.

Chon ct chng ma hiu K-103 la thoa man.

II. Tnh van khun dm va ct chng dm:

1. Tnh cho dm co tit din 300x700:

Tnh cho dm co tit din 300x700 cac dm khac co kch thc nho hn b tr nh dm nay la thoa. H van khun dm c t hp t cac tm ct pha a nng. Tai v tr tip giap cua hai tm ct pha t thanh . S dung cac tm ct pha 250x1000x50, 200x1000x50 va tm ni goc trong 100x100x50, tm ni goc ngoai 100x100x50.

a/ Tnh toan thanh ay dm:

Chon thanh thep dm la thep ng co tit din BxHxd = 50x50x1,5mm co: W = 4,568cm3, J = 11,419cm4. Tai trong tac dung ln tm van khun:

Trong lng btng ct thep: 2600.0,3.0,7 = 546kG/m.

Tai trong do chn ng cua btng: 100.0,3 = 30kG/m (theo tai liu Van Khun va Gian Giao cua Phan Hung - Trn Nh nh).

Tai trong van khun nha rt nho nn co th bo qua.

( qtc = 546 +30 = 576 kG/m

qtt = 546.1,1 +30.1,4 = 642,6 kG/m.

Thanh ay dm lam vic nh dm lin tuc k ln gi la ct chng.

S tnh:

Tai trong tac dung ln mt thanh ay dm (bo qua trong lng ban thn thanh ).

qtc = 576/2 = 288kG/m

qtt = 642,6/2 = 321,3kG/m




lcm.


cm.

Vy chon khoang cach gia hai ct chng < 138,6 cm. Ta chon khoang cach ln nht la: 120cm.

b. Tnh thanh ngang van thanh dm:

Tai trong ngang tac dung ln 1m dai thanh ngang:

Ap lc cua va btng mi : 2500.0,6 = 1500kG/m2.

Tai trong do chn ng cua btng: 200kG/m2.

( qtc = (1500 + 200).0,25 = 425kG/m

qtt = (1500.1,1 + 200.1,4).0,25 = 482,5 kG/m.

Chon thanh thep dm la thep ng co tit din BxHxd = 50x50x1,5mm co: W = 4,568cm3, J = 11,419cm4.

S tnh thanh ngang van khun thanh dm la dm lin tuc k ln cac thanh ng. Vic tnh khoang cach thanh ng theo hai iu kin:

+ Theo iu kin cng :

lcm.


cm.

Vy chon khoang cach gia hai thanh ng < 122 cm. Ta chon khoang cach ln nht la: 120cm.

c. Tnh toan ct chng:

S tnh ct chng la ct chu nen hai u lin kt khp. Vi khoang cach ct chng la 1,2m.

Tai trong tnh toan tac dung ln ct chng dm la: Ptt = 642,6.1,2 = 771,12kG

Chiu cao cn thit cua ct chng: 3,5 - 0,7 - 0,05 - 0,05 - 0,08 = 2,62m.

Tai trong tac dung va chiu cao cn thit nho hn so vi ct chng xa g san, nn chon ct chng K-103 la thoa man.

2. Tnh cho dm tai sanh on co tit din 300x950:

Do dm co chiu cao ln, nn ap lc tac dung cua va btng ln van khun thanh dm ln. V vy, am bao n nh ta b tr cac ty xuyn lin kt tm van khun trong va ngoai, cac thanh chng ng luc nay ch lam nhim vu nh v cho dm thng ng khi btng.

a/ Tnh toan thanh ay dm:

Chon thanh thep dm la thep ng co tit din BxHxd = 50x50x1,5mm co: W = 4,568cm3, J = 11,419cm4. Tai trong tac dung ln tm van khun:

Trong lng btng ct thep: 2600.0,3.0,95 = 741kG/m.

Tai trong do chn ng cua btng: 100.0,3 = 30kG/m (theo tai liu Van Khun va Gian Giao cua Phan Hung - Trn Nh nh).

- Tai trong van khun nha rt nho nn co th bo qua.

( qtc = 741 +30 = 771 kG/m

qtt = 741.1,1 +30.1,4 = 857,1 kG/m.

Thanh ay dm lam vic nh dm lin tuc k ln gi la ct chng.

S tnh:

Tai trong tac dung ln mt thanh ay dm (bo qua trong lng ban thn thanh ).

qtc = 771/ 2 = 385,5 kG/m

qtt = 857,1/ 2 = 428,6k G/m




lcm.


cm.

Vy chon khoang cach gia hai ct chng < 125,8 cm. Ta chon khoang cach ln nht la: 120 cm.

b. Tnh thanh ngang van thanh dm:

Tai trong ngang tac dung ln 1m dai thanh ngang:

Ap lc cua va btng mi : (.h = 2500.0,75 = 1875 kG/m2.

(vi h = max(0,75 va R), chon may m chn ng (116 co R = 0,35cm).

Tai trong do chn ng cua btng: 200kG/m2.

( qtc = (1875 + 200).0,25 = 518,75kG/m

qtt = (1875.1,1 + 200.1,4).0,25 = 585,6 kG/m.

Chon thanh thep van khun thanh dm la thep ng co tit din BxHxd = 50x50x1,5mm co: W = 4,568cm3, J = 11,419cm4.

S tnh thanh ngang van khun thanh dm la dm lin tuc chu tai trong phn b do tm van khun truyn vao, co gi ta la cac thanh ng (v tr t cac ty xuyn lin kt gia hai tm ct pha trong va ngoai). Vic tnh khoang cach thanh ng theo hai iu kin:

+ Theo iu kin cng :

lcm.


cm.

Vy chon khoang cach gia hai thanh ng (hay hai ty xuyn) < 114 cm. Ta chon khoang cach ln nht la: 100cm.

c. Tnh toan ct chng:

S tnh ct chng la ct chu nen hai u lin kt khp. Vi khoang cach ct chng la 1,2m.

Tai trong tnh toan tac dung ln mt ct chng dm la: Ptt = 857,1.1,2/ 2 = 514,3kG.

Chiu cao cn thit cua ct chng: 4,29 - 0,05 - 0,05 - 0,1 = 4,09m

Chon ct chng co ma hiu K-105, co chiu cao lam vic ti a la 4,5m; tai trong khi nen la 1,7(T).

3. Tnh dm bo (cong) tit din 200x400:

V dm cong nn ta khng th s dung nhng tm van khun nha a nng cu tao c. y, cu tao van khun dm ta t hp hai loai vt liu o la: van cho tm ay dm va tm thep mong lam thanh tao chiu cong.

Cu tao nh hnh ve:

a/ Tnh van ay dm:

Chon g lam van ay dm day 3cm. S tnh la dm lin tuc vi cac gi ta la ct chng van ay dm.

Tai trong tac dung ln van ay dm:

Trong lng btng ct thep: 2600.0,2.0,4 = 208 kG/m

Trong lng g van khun: 0,2.0,03.600 = 3,6 kG/m

Tai trong do chn ng: 100.0,2 = 20 kG/m.

( qtc = 208 + 3,6 + 20 = 231,6 kG/m.

qtt = (208 + 3,6).1,1 + 20.1,4 = 260,76kG/m.

Tnh khoang cach ct chng van ay dm:

+ Theo iu kin cng :

( = = 150kG/cm2. vi M = qtt.l2/ 10; W = b.h2/ 6

( l ( cm.

+ Theo iu kin vong:

( =

Chon khoang cach ln nht gia hai ct chng ( 85,35cm. Chon khoang cach ln nht la: 80cm.

b/ Tnh ct chng:

Lc ma ct chng phai chu: Ptt = 260,76.0,8 = 208,6 kG < 915,9 kG nn chon ct chng ma hiu K-103 la thoa man.

III. Van khun ct va gng ct:

Khi tnh toan van khun ct, thin v an toan ta ly ap lc va btng tac dung ln van khun thanh trn sut chiu cao bng ap lc va btng tai ay ct.

H van khun ct cung c t hp t cac tm ct pha a nng. S dung cac kiu lp ghep tao goc ngoai. Tai v tr tip giap gia cac tm van khun t cac thanh ng, gi ta cua cac thanh ng la cac gng ct. ct c thng ng th ta s dung thanh chng thep chng vao b gng ct. Tnh cho ct co kch thc ln nht 700x700, cac ct con lai lam tng t.

S dung cac tm ct pha a nng: 300x1000x50, tm ni goc ngoai 50x50x100.

Hnh ve van khun ct:

Tai trong tac dung ln thanh van khun ct gm:

+ Ap lc cua va btng mi tac dung ln thanh van khun.

P = (.h

S dung may m chn ng (116 co cac thng s ky thut nh sau :

Nng sut : 3 ( 6(m3/h)

Ban knh anh hng : R = 35cm.

Chiu cao cua lp btng: h = 3,5- 0,5- 0,03 = 2,97m

Vi: 3,5m la chiu cao ct tng trt.

0,5m la chiu cao dm.

0,03m la chiu cao khi btng ct cach dm.

Chiu cao lp btng: h = 2,97 >R = 0,35m va > 0,75m nn chon h = 0,75m.

( P = 2500.0,75 = 1875 kG/m2.

+ Tai trong do chn ng phat sinh khi btng: P = 200kG/m2.

+ Tai trong do m va btng, tnh bng 200kG/m2 b mt ng cua van khun. Tuy nhin tai trong nay ch tnh khi khng k n tai trong chn ng. (tai liu Van Khun va Gian Giao cua Phan Hung, Trn Nh nh).

Vy tai trong tac dung vao thanh van khun:

Ptc = (.h + P = 1875 + 200 = 2075kG/m2.

Ptt = 1,1.1875 + 1,4.200 = 2342,5kG/m2.

Tai trong phn b tac dung ln thanh ng van khun ct, vi khoang cach ln nht gi hai thanh ng la 0,3m.

qtc = 2075.0,3 = 622,5kG/m

qtt = 2342,5.0,3 = 702,75kG/m

S tnh thanh ng la dm lin tuc chu tai trong phn b u do van khun thanh ct truyn vao vi cac gi ta la gng ct.

Chon thanh ng la thep hp co tit din BxHxd = 50x50x1,5mm; co W = 4,568cm3, J = 11,419cm4.

Xac nh khoang cach gng ct:

- Theo iu kin cng :

lcm.

- Theo iu kin vong :

Chon khoang cach gia cac gng ct

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Thuyet Minh Thi Cong 1 - c