do an hiep

8/8/2019 do an hiep.

1/36

N THI CNG CU GVHD:NGUYN NH KHANH

PHN M U Chng I: GII THIU NI DUNG N

Cc s liu ban u1. a hnh:

Cu qua song L32 thuc th trn A-tnh B thuc khu vc ng bng.2. a cht: a cht khu vc xy dng cu c chia thnh 3 lp kh r rt:

- Lp Ct dy 8.7m- Lp Ct dy 7m- Lp St dy v cng

3. Thu vn:- Mc nc cao nht : +21.5m.- Mc nc thng thuyn: +20.50 m.- Mc nc thp nht: +19 m.

4. Kh hu - Thi tit:- Khu vc xy dng cu c kh hu nhit i gi ma. Thi tit khng phn

chia r rt theo ma, tuy nhin lng ma thng tp trung t thng 10 nm ny nthng 1 nm sau.

- Chu nh hng trc tip gi ma ng Bc vo nhng thng ma.

- m khng kh kh cao (v nm vng gn ca bin ). I.5 Cc tiu chun k thut ca cng trnh:

- Qui m xy dng : Vnh cu.- Tn sut l thit k : P =1%.- Ti trng thit k : Hot ti H30 v on ngi 4MPa.- Khu cu: L=106.4.- Kh cu : K = 7+ 2x1,5 m.

- Cp sng : sng khng thng thuyn

SVTH:NGUYN THANH HIP LP K12XCTRANG1


2/36


Chng II :CC IU KIN T NHIN CA CNG TRNH II.1 iu kin a hnh:

Mt ct dc sng kh i xng, do rt thun tin cho vic b tr kt cu nhp

xng.Sng cp khng thng thuyn v khu cu L =106.4 m.

II.2. Tnh hnh dn c:- Qua kt qu bo co v kho st thng k cho thy khu vc u t xy dng c m phn b dn trung bnh, ngh nghip ch yu l nng nghip v tiu th cnnghip, bn cnh l bun bn nh v tp trung nh hng qun, ch ba trong vng Nhn dn y cng l ngun nhn lc cn thit trong qu trnh xy dng cng trnh

cu II.3. iu kin n, , sinh hot ca cng nhn- Ln tri c xy dng gn cng trnh. H thng in, nc, thng tin lin lc cc nhu yu phm trong sinh hot c m bo y . II.4. Chn thi gian thi cng:- Da vo cc s liu c kho st thng k v a hnh, a mo, a cht thu vthi tit kh hu, iu kin giao thng, vn ti ta chn thi gian thi cng t u thhai. Thi cng sm hn s gp ma v gi rt, cn thi cng mun hn s gp ma

cui giai on xy dng cu. Nu nh vy vo ma ma s khng tin, tin tcng s khng m bo, iu kin thi cng s gp nhiu kh khn, cht lng ctrnh kh t c nh thit k. II.5. iu kin cung ng vt liu: II.5.1. Ngun vt liu ct, si sn v cc vt liu xy dng cu khc :

- Ngun vt liu ct, si sn : C th dng vt liu a phng. Vt liu ct, ssn y c cht lng tt m bo tiu chun lm vt liu xy dng cu

--

Qua kho st v thm d th vt liu nh , ct, si a phng m bv yu cu khai thc v cht lng phc v cho cng trnh , gi thnh kh r ng c nhu cu xy dng cng trnh.

- Vt liu thp : S dung cc loi thp ca cc nh my luyn thp trong nc nh thThi Nguyn, Bin Ho...hoc cc loi thp lin doanh nh Vit_Nht, Vit _c...- Xi mng : Hin nay cc nh my xi mng u c xy dng cc tnh, thnh lunp ng nhu cu phc v xy dng. V vy, vn cung cp xi mng cho cc cntrnh xy dng rt thun li, gi r lun m bo cht lng v s lng m yu ccng trnh t ra.



3/36


-- Bn cnh thun li trn cn c thun li na l cng trnh gn c s sn xuvt liu xy dng ch yu nh xng v cc loi vt liu bn thnh phm. Cc cong dn n cng trnh cn khai thc c , thun li cho vic vn chuyn vt ln cng trnh , hai u bi sng cn rng thun li cho vic xy dng ln tri, cn

trnh ph, bi c cc.-- Ngun in chiu sng phc v cho vic xy dng v sinh hot c m bv cung cp y 24/24.

-- Tnh hnh dn c khu vc ny khng nhiu nhng rt thc t gic v tinhthn bo v cao s to iu kin thun li cho vic xy dng v bo v ti sn ctrnh. II.5.2. Nhn lc v my mc - thit b :

-- Cng ty trng gi thu thi cng cng trnh ny c y phng tin v thit b phc v thi cng, i ng cng nhn v k s chuyn mn cao v dy dn kinhnghim trong vn thit k v xy dng, hon ton c th a cng trnh vo khathc ng tin .

-- c bit i ng k s v cng nhn dn tip cn c nhng cng nghmi v xy dng cu. Mt khc khi c cng vic i hi nhiu nhn cng th c ththu dn c trong vng, nn khi thi cng cng trnh khng b hn ch v nhn lc. Cni vi my mc thit b cng c th thu nu cn



4/36


Chng III : XUT LA CHN PHNG N MNG

La chon phng an thi cng sao cho phu hp am baocac yu cu sau:- am bao an toan tuyt i cho ngi tham gia thi cng va

cho cng trnh- am bao tnh cht ky thut cua cng trnh (cht lng va

my quan)- am bao hoan thanh ung tin e a cng trnh vao

khai thac.- am bao gia thanh re.

Chon phng an thi cng mong coc s dung coc ucsn:

a-Phng an 1 : Thi cng trn can bng cach san lpt,ong vong vy coc van, sau o ong coc.

-u im:Li dung t co sn cng trnh ui ra tao mt bngGia bua t trn nn t a san bng nn trong qua trnh thi

cng la n nh, an toan lao ng la rt cao, nh v coc va dichuyn gia bua n gian d dang, khng phai tn kem lam gian gia bua va tn thi gian lam san ao. Giam ang k thigian hut nc h mong (nu co) v qua trnh ong coc trn hmong cha ao.

-Nhc im:ao t h mong ch dung phng phap ao thu cng nn thigian thi cng h mong keo dai. Nu dung may ao gu ngoam thcn ngi ch huy iu khin gu khoi va vao coc lam gaycoc. Con dung may ao gu thun hoc may ao gu nghch haymay ui th rt d lam gay coc.

b-Phng an 2: Thi cng di nc bng s lan, ong vongvy coc vn thp sau o ong coc.

- u im:Khng phai ui t ra tao mt bng cho gia bua thi cng.

Thi cng tai v tr co mc nc thi cng ln.- Nhc im:

Ph thuc vo thi tit,mc nc ln xung.Trong thi gian ba hot ng s lan phc neo gi c nh ti thi im thi cng

Vy Qua phn tch a hnh khu vc thi cng ta nhn thy: do mc nc thi cng thp nn phng n thi cng trn c l kh thi nht. Do vy chn phng n 1 d thi cng mng.



5/36


Chng III :BIN PHP K THUT V TRNH T THI CNG TR II. Trnh t thi cng chung tr s 1:Trnh t thi cng tr 1 gm cc bc nh sau:

- Tp kt vt t thit b thi cng.- nh v tim tr (dng my + nhn cng)- Thi cng vng vy cc vn thp.- o t h mng bng my kt hp nhn cng n cao thit k.- ng cc b tng ct thp .- Sa sang h mng, tin hnh btng bt y bng phng php va dng.- Ht nc v v sinh li h mng.- Nghim thu h mng.- p u cc v tin hnh lp btng m.- Lp dng ct thp, vn khun v tin hnh btng b tr.- Khi btng b tr t cng , tho d vn khun, lp t h mng

cao nh b mng.- Lp dng ct thp, vn khun v tin hnh btng thn tr T3.- Khi btng thn tr t cng , tin hnh tho d vn khun-Lp dng vn khun x m v b tng x m-Khi b tng t cng tho d vn khun va hon thin tr

II.Cc c im khi thi cng: Tr s 1l dng tr thn hp mng cc i th p, phn b tr nm trong

mt t t nhin 1.5 m, khi thi cng lm mng th ta o lp t nyi, thi cng xong b tr ta s dng t p li.

Cc ng cho tr l dng cc ma st di 18m, k t y b, tit din ccl 3535(cm), v cc di nn sn xut thnh 2 t ng, mi t di9m.

y vi lp t khng ln lm c nc mt, qua o c mc nc tithi im thi cng +0.5 m. Vi mc nc nh vy thi cng b cc tadung phng php san t ra v tr thi cng sau o t h mng , b

tr vng vy ngn nc, y phn b mng nm trong lp ct khi thi



6/36


cng phn b mng ta phi thi cng lp b tng bt y tnh ton sau ngn nc chy vo h mng .

Khi thi cng ta cho cc ngm vo b mng mt on l 0,15m v phnu cc cn x l l 0,35m.

Vic thi cng mng cc trc tin phi chun b vt liu, vt liu bnthnh phm, c bit l cc. Chun b ln tri lm ni cho cn b v cng nhn, kho, bi cha vt

t, vt liu; chun b mt bng thi cng, mt bng c cc v cc cukin khc......

II.K THUT CC TRNH T THI CNG CHI TIT V TNH TON II.1. Xy dng nh ,ln tri cho cng nhn:

Cng tc ny tin hnh ngay cng nhn c ni sinh hot ti cng trng.Vnchuyn g,tn,... xy dng ln tri cho cng nhn v xy dng kho bi cha vliu.Kt ni v xy dng h thng in ,nc phc v trong qu trnh thi cng. II.2. Chun b vt liu v c cc :

-Chun b vt liu-Ch tao coc vi kch thc 35 35 cm.-Co th ch tao tai cng trng hoc tai nha may-Lam bai uc coc co nn bng b tng xi mng co chiu day

h = (10 15) cm.

Hoc nn bng cat soi m cht hoc cat a dm day h= (10 15) cm.-Lp van khun-Lp ct thep c ch tao trc- b tng va bao dng b tng-B tng at cng 70% th vn chuyn coc xp vao

kho- Khi cc t 100% cng mi vn chuyn ti chn cng trnh v tin hn

dng, ng cc.-Co th ch tao coc chng ln nhau tit kim din

tch bai ch tao coc-Vn chuyn vao kho th phai xp chng ln nhau, phai ung

v tr moc cu.-Ch tao coc sau 24 ting ng h co th thao van khun

ch tao coc tip theo.-Theo nhim vu an th mi coc dai 19m nn ta co th

chia ra lam 2 oan cocmi oan dai 9 m.


S C CC


7/36


LP MCATDA Y10cm

THE PGO CL50x50x5

THE PBA Nd=5

KHUNGTHE P

35 35 35 35 35

3 5

II.3. nh v tim tr :

- Mc ch: Nhm m bo ng v tr, kch thc ca ton b cng trnh cng nhcc b phn kt cu c thc hin trong sut thi gian thi cng.- Ni dung:

+ Xc nh li v kim tra trn thc a cc mc cao v mc nh.+ Cm li cc mc trn thc a nh v tim cu, ng trc ca cc tr m

v ng dn u cu.+ Kim tra li hnh dng v kch thc cc cu kin ch to ti cng trng.

+ nh v cc cng trnh ph tm phc v thi cng.+ Xc nh tim tr cu bng phng php giao hi, phi c t nht 3 phngngm t 3 mc c nh ca mng li.T1- Cch xc nh tim tr:

- AA1, AA2 : l cc dng chun o chnh xc( A cch A1 v A cch A2 khongcch bng nhau v bng 8.66m


C

180m 15m

900

900

B1

B

B2

900

900

600

600103,92m

103,92m

8,66m

8,66m

A1

A

A2

600

600


8/36


- cch xc nh: Dng ba my kinh viw xc nh tim m, c th:+ t 1 my ti A nhn v B theo hng tim cu+ t 1 my ti A1 nhn v A quay 1 gc 60o

+ t 1 my ti A2 nhn v A quay 1 goc 60o

Giao hi gia ba dim l tim m. Ti B tin hnh tng t sau tin hn bnh sai

II.4. Cng tc chun b thi cng:- Khi thit k t chc thi cng cc ng cn phi iu tra v thu thp cc ti liu sau:

+ Bn v thit k mng cc, kh nng chu ti, cc yu cu th ti v phn php kim tra nghim thu.

+ Ti liu iu tra v mt a cht, thy vn nc ngm.+ Ti liu v bnh , a hnh ni thi cng, cc cng trnh h tng ti ch nhng giao thng, mng in, ngun nc phc v thi cng.

+ Ngun vt liu cung cp cho cng trnh, v tr ng cc .+ Tnh nng v s lng thit b my thi cng c th huy ng cho cng trnh.+ Cc nh hng c th tc ng n mi trng v cng trnh ln cn.+ Trnh cng ngh v k nng ca n v thi cng.+ Cc yu cu v k thut thi cng v kim tra cht lng cc ng .

- Cng tc t chc thi cng cc ng cn thc hin cc hng mc sau :+ Lp bn v mt bng thi cng tng th bao gm: v tr cc, s bi c c

ng vn chuyn cc v phng tin vn chuyn cc. Dy chuyn thit b cng ngthi cng nh my ng, cc thit b ng b i km, h thng phao ng cc trnc, h thng cp in nc .

+ Cc bin php m bo an ton lao ng v cht lng cng trnh.- Trc khi thi cng cc ng phi cn c vo cc bn v thit k thi cng ti

hnh xy dng cc cng trnh ph tr nh :+ ng cng v vn chuyn my mc, thit b, vt t phc v thi cng .+ s lng v cht lng cc ng yu cu v phi c cc d phng khi th

cng cc phi thay cc .+ Lp bn v th hin cc bc thi cng, cc ti liu hng dn cc thao tc th

cng i vi cc thit b ch yu, lp qui trnh cng ngh thi cng cc ng hdn, ph bin cho cn b, cng nhn tham gia thi cng lm ch cng ngh- Mt bng thi cng ph thuc vo a hnh: y ta s dng h phao ni t mng v neo c nh h thng phao ni.



9/36


II.5. Thi cng vng vy cc vn thp :- tin hnh xy dng tr s 3 ta phi tin hnh xy dng h thng ngn nc mv t ct chy vo h mng lm cn tr thi cng. Chnh cao t MNTC n CM l

5,5m (cha k chiu dy lp btng bt y). V vy chn phng n thi cng ngnnc bng vng vy cc vn thp l hp l v kinh t nht.- Chn loi cc vn kiu Lacxen IV c cc thng s k thut v kch thc nh sau:

+ Mmen qun tnh ca 1m tng cc vn l : 39600 cm4

+ Mmen qun tnh ca tng cc vn ring l l : 4640 cm4

+ Mmen khng un ca tng cc vn ring l l : 405 cm3

+ Mmen khng un ca 1m tng cc vn l : 2200 cm3

+ Din tch tit din l : 94,3 cm2

+ Khi lng n v di l : 74 kg/m

- Ti cc gc ca cc vn ta lin kt bng thp gc nh hnh v. Kch thc ca b tl 3 x 8(m2) v kch thc ca cc vn thp nn ta chn kch thc vng vy cc vnthp l 4 x 9,2(m2). S lng cc vn thp c ly nh sau:

- Cnh ngn ly : 10 cc- Cnh di ly : 23 cc- 4 gc dng 4 cc lin kt

Tng cng dng 66 cc Lacxen v 4 cc lin kt gc.II.6. Cng tc o t h mng:- Bin php o t trong h mng trong trng hp ny h mng c nc nn khng tho bng nhn cng c. Da vo iu kin a cht ca lng sng ta chn bin php cng c gii o t. Vi cao y b tr ta xc nh c phm vi o t trong lt u tin l ct, dng my o gu ngom o t. t o ln phi c vn chuyvo b ni khc m bo khng thu hp dng chy.


2 0 4

, 51 4 ,8 1 2

400Thp gc

L 100x100x10


10/36


- Trong qu trnh o ch phi m bo khng ph hoi cu trc t nhin ca t n cao thit k. V vy khi o n cao cch C thit k 0,3 0,5m th dngthit b nh hn sa san li h mng trc khi xy dng cng trnh.

II.7. Thi cng ng cc :Sau khi c cc 100% cng theo thit k v xc nh chnh xc

tim trcu, ta tin hnh thi cng ng cc trbng ba ng cc Diezel.Khi chn ba ng cc ta phi cn c vo cc yu t sau :

-- Loi ba s dng rt nh hng n hiu qu cng tc ng cc, ty thetrng lng cc, su ng cc, yu cu kh nng chu lc ca cc v iu kin cng chn ba cho hp l.

-- Theo cng thc kinh nghim nng lng W ca mt nht ba t nht phi lnhn 25 ln sc chu ti gii hn ca cc.

- Nng lng xung kch ca ba phi m bo :W 25 Pgh (N.m)

Trong :W : Nng lng xung kch ca ba.

Pgh : Kh nng chu lc gii hn ca cc, Pgh = m K P

.0

Vi P0 : sc chu ti tnh ton ca cc theo t nn (KN)P0 = 586,28 (KN)K : H s ng nht ca t, K = 0,70m : H s iu kin lm vic, ph thuc vo s lng cc, cu to b

mng .m = 1.

Pgh= 7,0.128,586

= 837,54 (KN)

Vy : W 25.837,54 = 20938,50 (N.m)=20,94 (KN.m)Vi s liu tnh ton trn, ta chn ba Diezel kiu ng ng S-1047 . Ba c

cc thng k thut sau :+ Trng lng ba : 2,5 (T)+ Trng lng ton b : 5,5 (T)+ Kch thc gii hn : cao 4,97 (m), rng 0,89 (m)+ Nng lng xung kch : 37 (kN.m)+ Tn s va p : (43 45) ln/pht+ cao nng ba ln nht : 3(m)



11/36


- H s thch dng ca ba :

K=9,81 W qQ+ K max

Trong :Q : Trng lng ton b ca ba (Q = 5,5 (T) = 5500(KG))q : Trng lng ca cc, m u cc, m ba, cc m

q= 2,5.0,352.9,5 + 2 + 2 = 6,9 (T) = 6900 (KG)W : Nng lng xung kch ca ba chn. W = 20938 (N.m)

Ta c : K = 9,81.5500 690020938

+ = 5,8

K max l h s tra bng , ng vi cc BTCT K max = 6 > K = 5,8t yu cu v h s s dng ba.

- Tnh ton chi ca cc :-- Trc khi cu cc vo gi ba ng cn nh du cc theo chiu di bn

cc vt sn tin cho vic theo gii ln xung ca cc trong qu trnh ng

ui cc nh cc vt sn vi khong cch 1(m) v cng gim dn v u cc 20; 10; 5 (cm).-- Cc phi ng cho n khi t c cao thit k.-- chi ca cc c tnh theo cng thc :

e = )./(.....81,9

F nm p P H Q F nm

+. qQ

qk Q+

+ .

Trong :++ Q : Trng lng ton b ca ba; Q = 6 (T)

++ q : Trng lng ca cc, m cc, m ba, cc dn ; q = 6,9 (T)++ m : H s an ton ; m = 0,5 cho cng trnh vnh cu .++ n : H s ph thuc vo vt liu lm cc v h cc : n = 1470 .++ k : H s phc hi ph thuc vo vt liu lm cc : k = 0,2 .++ F : Din tch tit din ca cc : F = 0,350,35 = 0,123 (m2).++ P : Ti trng gii hn ca cc. P = 837,54 kN++ H : cao ri ca ba : H = 3 m.

e = )123,0.14705,0/28,586(586,28.3.6.123,0.1470.5,0.81,9

+ .

6 0, 2.6, 9

6 6,9

++ = 0,0028 (m)



12/36


= 2,8 (mm)Trong qu trnh ng cc cn phi theo di chi ca ba. Tuy nhin cng cn

ch n hin tng chi gi khi ng cc. Nu sau khi ng cc xong m tin hnkim tra ngay chi th s cho kt qu khng chnh xc, l hin tng chi gi

Cc c ng vo lp ct ht trung do s thu c chi < chi thc t. C phi cho ngh 2 - 3 ngy cho tnh cht cu t phc hi th mi ng cc. chi khng c nh qu m cng khng c ln qu, thc t t 2 - 5 mm

Nu nh hn 2 mm th cn chn li ba nng hn.Trong thc t c th xy ra cc trng hp sau:

+ Khi ng n cao thit k m cha t chi (> etk ) th phi tip tcng na cho n khi chi.

+ Nu ng cha n cao thit k m chi th c th khng cn n

na nhng phi ng vi loi ba tnh chi v ng vi nng lc xung kch tnhton.

-Chn gi ba:Gi ba dng h cc, nhc t ba, nh hng chiu di chuyn ca h cc

ba trong qu trnh ng cc.Chiu cao cn thit ca gi ba xc nh theo cng thc:

H = h1 + h2 + h3 + h4 h1 + h2 + h3

Trong :++ h1 : chiu di cc cn ng; h1 = 9 m (V ng tng on v ni cc)++ h2 : chiu cao ca ba; h2 = 4,97 m++ h3 : chiu cao nng ba; h3 = 3 m++ h4 : Chiu cao treo buc.

H = 9 + 4,97 + 3 = 16.97 (m)Chn gi ba hiu SP-33A chy trn ray c cc thng s sau:

- Chiu cao tha p: 20,4 m

- Sc nng trng lng cc v qu ba: 10 T- Cng sut ton b ca ng c in: 31,5 KW- Trng lng: 25T- Chiu rng ng ray: 4,5 m.- Tm vi : 6,2 m.- nghing gc vpha trc : 1/8, vpha sau : 1/3.- Kich thc gii hn : H = 20,4 m, B = 5 m, L = 9,6 mKhi ng cc trn nh cc phi c m cc gim nh lc xung kch tc dn

trc tip ln u cc v dn n ng sut trm ton b tit din cc. C th dng ch



13/36


u cc lm bng thp c di dng m, i hi lng quanh u cc, cho ccth xoay t do trnh nhng ng sut ph v khng c rng qu mi bn 1cm. su ca chp khong 1,5 - 2 ln cnh cc.

-K thut ng cc:- Sau khi b tr m lt, ta h ba t trn u cc. Chnh hng v kim tra v

tr cc ln cui cng bng my trc t ly tim cc theo ng bt mc c hhng.

- Sau cho ba ng nh vi nht cc cm vo t v kim tra cc, bah thng dy v n nh ca gi ba. Cui cng cho ba hot ng bnh thng.

- Trong qu trnh ng cc phi theo di thng xuyn v tr cc, nu pht hinsai lch cn chnh li ngay. Theo di tc xung ca cc phi ph hp vi lp ca cht. Nu t nhin cc ngng xung hoc ln gim t ngt v ba ny dln, chng t cc gp chng ngi. Nu khng qua c vt cn cc s gy, bhiu bi hin tng cc tt xung t ngt v trc tim cc b chch hng. Khi mcc b gy, s xy ra hin tng cc xung khng u, khi nhiu khi t. Cc gy phnh ln thay cc mi. Trong qu trnh ng cc phi c nht k theo di cc s c vnhng pht hin tnh hnh cc xung khng bnh thng phi ghi r.

- Nng sut ng cc ph thuc vo cc yu t sau nh thi gian di chuyn cgi ba t cc ny n cc tip theo, nng v dng cc vo v tr ng, iu chnh vnh v cho ton h trc khi ng. Phn ln thi gian u dnh cho khu chun bng tc ng cc trc tip ch chim khong 20 - 30% thi gian. V vy phi tnh cho gi ba di chuyn hp l, vic cung ng v nh v nhanh nht theo nguyn tcng cc trc khng nh hng n vic ng cc sau, ng di chuyn gi bthun li nht.

+ Cng tc ng cc :

Nguyn tc ng cc : ng theo trnh t sao cho thi gian ng v di chuyngi ba l t nht. Di chuyn gi ba sao cho cc cc ng ri khng lm nh hngn cc cc ng sau .

+Sau khi b tr m lt,h ba t trn u cc.Chnh hng v kim tra v trcc ln cui cng bng my trc a.

+Cho ba ng nh vi nht cc cm vo t v kim tra cc,ba,h thngdy& n nh gi ba.Cui cng cho ba hot ng bnh thng.



14/36


Ch :-Trong qu trnh ng cc phi nh v tim cc trong mt bng bng thc kp v

my kinh v. Trong qu trnh ng cc dng dy di,thc tam gic kim tra

thng ng ca cc kp thi iu chnh. Cn ch n cng tc an ton v n nhgi ba.-Trong sut qu trnh ng cc phi theo di chi ca cc.Nu tr s nh hn

2(mm/nht ba) th phi thay ba.

- Trnh t ng cc:Qu trnh ng cc phi tun theo nhng nguyn tc sau:

+ a ra s sao cho hnh trnh di chuyn thit b nh nht v d dngnht,an ton

+ Cc cc h trc khng cn tr cc cc ng sau .+ Cc cc h trc khng chn p,khng lm x lch cc cc sau

-S ng cc:

II.8. Thi cng lp b tng bt y:- b tng bt y:

Sau khi ng cc xong, ta tin hnh b tng bt y, lp b tng bt y c tcdng :+Ngn nc vo h mng



15/36


+To mt bng thi cng+Ngn t tri vo h mng

1. Xc nh chiu dy lp BT bt y

+5.7m

+2.2

CDM:+0,2m

Lp BT bt y chu p lc y ni ca nc t di ln khi ht cn nc bn tronvng vy.iu kin 1: Trng lng lp b tng phi ln hn sc y ni ca nc. Xt chotrng hp c k n lc ma st gia cc v b tng.- Gi X l chiu dy lp b tng bt y

m( n. b.x.F + u1.[ ]1 .x +k.u2. [ ]2 .x) n.hn.F

[ ] [ ]1 1 2 2. .

( . . . . . ) .n n

n

h F x

m n F u k u F

+ + .

Trong :-F: din tch y h mng

F = 4.9,2 = 36,8 (m2)- hn:chiu cao mc nc thi cng tnh t y b mng, hn =2 (m)- b: trng lng ring ca b tng b =2,5(T/m2)- n: trng lng ring ca nc, n =1(T/m2)- u1:chu vi h mng, u1= 2(4+9) =26(m)- u2:chu vi tit din 1 cc, u2= 0,35.4 = 1,4(m)-[ ]1 :lc ma st gia tng cc vn v lp b tng bt y, [ ]1 =3(T/m2)-[ ]2 :lc ma st gia cc v lp b tng bt y,[ ]2 =6(T/m2)-m: h s iu kin lm vic,m= 0,9-k:s lng cc trong mng,k = 21(cc)-n:h s ti trng,n=0,9

Thay tt c vo bt phng trn ta c:



16/36


2,5.5,5.36,81,67

0,9(0,9.2,5.36,8 26.3 21.1,4.6) 1.36 x =

+ +

x X 1,67 m (1)

b iu kin 2: Tha mn iu kin v cng - n gin ta xem lp b tng bt y l dm n gin k ln hai gi

- cng lp b tng bt y m bo chu lc th phi tha mn iu kin sau:

max= k RW M

max

Trong :M: momen ln nht gia nhp

Mmax 218

ql =(l:khong cch ln nht gia cc cc,l=1,2m)

Mmax 21

8ql = 21 1,44.1,2

8 8q q= =

q = qn-q bq = n(hn +x)=1.(5,5+x)q b= b.x =2,5.x

q= 5,5 +x-2,5x = 5,5-1,5x(T/m2- Lp b tng bt y s dng loi b tng M150 1x2 c R k = 65 (T/m2)

W 21. .6 b x=

b=1W 21.1.6 X =

max

2

1, 44(5,5 1,5 )

8 6516

k

xM

RW

x

= =

520x2+12,96.x-47,520 ()- Gii (*) ta c: x 0,29 m (2)- T (1) v (2) ta chn x = 1,7 (m)


g


17/36


- Th tch b tng cn l:V = 9,2.4.1,7 = 62,56 m3.

- Thi cng BT bt y bng phng php ng .a. Ni dung:

- btng vo phu, phu phi c nt gi, khi btng lng tnh ton th ct dgi nt sau lin tc, va va nng dn ng ln theo chiu thng ng, tuyi khng c dch chuyn ngang. u ng lun ngp trong btng 1 khong thequy nh.- Phng php ny cho nng sut cao v m bo cht lng hn c v hn ch mtip xc gia btng v nc..

b. Thit b :- ng : c lm bng thp l nhng ng lp ghp tng on c tit din hnh trng knh D = 20cm, chiu dy ng = 4mm.- Phu: c lm bng thp c b dy = 4mm xung quanh c np bng st gc tng cng cng.- Nt gi: c lm bng thp l hoc bng cao su. Yu cu nt gi l d tt xung v

ni ln trn mt nc sau khi ra khi ng.- Khi BT bt y :

+ Phu phi th tch cha m trn u tin, c khi lng v c p l thng p lc nc y nc trong h mng ra ngoi

+ Th tch phu < 3m3 v > 1,5 ln th tch ng m bo p lc, khi lngv vn tc ca btng khi .

+ S lng ng ph thuc vo din tch h mng, bn knh tc dng v nng

sut my trn btng+ m bo nng sut btng qua ng > 0,3 0,4 m3 btng trn 1 din tchh mng v trong 1h.

+ Bn knh tc dng R < 3 4m, chn R = 4m, s ng l 4 b tr 1 hng.+ Cng ca BT bt y chn cao hn cng thit k 15 20%, btng

c st ln d xung v khng b tc, st = 18 20cm.+ btng di nc phi chun b chu o, lin tc v cng nhanh cng

tt.



18/36


+ Sau khi btng t cng 50Kg/cm2 th tin hnh ht ncII.9. Thi cng b tr:

Sau khi ng cc xong, tin hnh p u cc, un ct thp ccLm lp m b cc bng 1 lp b tng dy 20(cm) to bng phng, lm

v sinh sch s, tin hnh lp dng vn khun v b tng b tr

THI CNG TR S 1

Kch thc ca tr s 1:

Tnh ton cc vn thp:- thi cng vng vy cc vn, cc tng vnh ai c ch to sn trn b, sau ra v tr thi cng bng cn cu ri ng cc cc nh v, tip da vo vnh ai ng cc vn thp. Tng cc vn c gia c bng vnh ai hnh ch nht v bn

thanh chng ngang dc v cho gc. Cc b phn gia c c t dn theo qu trnthi cng v c cu to sao cho thun tin cho vic lp t v tho d.



19/36


- h cc vn thp vo t dng h thng ba, gi ba t trn x lan. trnh chng cc khng b nghing v khp kn theo chu vi th phi t ton b tng hocmt on tng vo v tr khung dn hng. ng cc lm 2 hoc 3 t ty theo su cn ng. Cc b phn ngm cc u phi c bi trn m trc khi ng. K

h thng ng gia cc cc cn phi c trt t st do trnh nc r r vo.- Cc nguyn tc tnh ton:- Vng vy cc vn c xem l tuyt i cng- p lc t tc dng ln tng cc vn ly theo nh l Culng vi mt ph hoi mt phng.- y ta chn vng vy cc vn thp c 1 tng khung chng. Do cn kim tra vmt n nh v tr v bn ca cc b phn c trong vng vy. Ta i xt 2 trng hnh sau:

+ Giai on 1: H mng o ti cao ca y lp btng bt y. Ht ramt phn nc trong h mng thi cng khung chng .

+ Giai on 2: H mng bt y. Nc trong vng vy ht cn. Cc vnc xu hng quay quanh im O nm cch mt trn ca lp b tng bt y khon0,5m v pha di.* Xt giai on 1:+ Xc nh chiu su ngm cc vn:

- S tnh :

+ Lp 1 : st do cng 9m c cc ch tiu c l sau:



20/36


1 = 2,00 (T/m3)1 = 0,551 = 29c1 = 0,11

+ Lp 2 : Ct ln si dy 4m c cc ch tiu c l sau:1 = 1,90 (T/m3)1 = 0,651 = 32c1 = 0,02

+ Lp 3 : Ct ht th dy v cng c cc ch tiu c l sau:3 = 1,90 (T/m3)3 = 0,653 = 38c3 = 0

- D kin cc vn thp s ng xuyn qua lp 1- i vi t nm trong nc ta tnh vi dung trng y ni

( )

+= 1

.1 0dn

Trong :

+l t trng ca t

= 2,65 (T/m3

)+ 0 l dung trng ca nc 0 =1 (T/m3)+ l rng trung bnh gia cc lp t = 0,55

=> ( ) 32,65 1 .1 1,06( / )1 0,55dn

T m = =+

+ Cc h s:H s vt ti ca p lc t ch ng: na = 1,2H s vt ti ca p lc t b ng: n b = 0,8

H s vt ti ca p lc thy tnh ly n = 1H s p lc t ch ng:

2 0 145 0,332a

tg

= =

H s p lc t b ng:2 0 145 3,06

2btg

= + =

- p lc thy tnh:P1 = n.h1=1.1,32 = 1,32(T/m2)



21/36


E1 =21 .(h 21 . n) = 0,87(T/m)

P2 = P1= 1,32(T/m2)E2 = h2.P1 =1,32.(3,95+ t) = 5,21 +1,32t (T/m)

- p lc t ch ng:E3 = aan nt ....

2

1 2 = 0,5.t2.1,2.0,33.0,95=0,188t2 (T/m)

- p lc t b ng:

E4 = bbn nt ....21 2 =0,5.t2.0,95.0,8.3,06 =1,163.t2 (T/m)

- iu kin m bo n nh chng lt:ML m.MG (1)

Trong :+ ML : Tng mmen cc lc gy lt i vi im lt O.+ MG : Tng mmen cc lc gi i vi im lt O.+ m : h s iu kin lm vic, m = 0,95. ( )1 2 3.1,67 .(1,7 ) / 2 . 1,7 .2 /3 LM E E t E t = + + + + 88,17.96,6.033,1.125,0 23 +++= t t t m. ( )40,95. . 1,7 .2 /3GM E t = +

23 82,5.737,0 t t +=

T iu kin (1) ta c c:0,121.t3 + 7,79.t2 6,96.t 17,88 0

- Gii ra ta c kt qu nh sau:t 1,99m.

- Chn: t = 2,00 m. t l chiu su cc vn ngm vo t sau khi o n cao y b tong bt y.+ Tnh n nh cc vn thp v tnh ton thanh chng:- Vic tnh ton cng ca cc vn ta xem cc vn thp l 1 dm n gin k ln gi l thanh chng ngang v gi di l im gia ca chiu su ngm cc vn vo t ca cc vn thp. Ti trng tc dng gm: p lc t ch ng v p lc nc nngoi h mng v b qua p lc t b ng v p lc nc trong h mng.- Theo kch thc ca vng vy ta dng 4 thanh chng cho.- S tnh duyt cng cc vn v tnh thanh chng :- Xc nh cc tr s tung biu p lc:



22/36


+ p lc thy tnh:P5 = ( ) )/(27,6.5,027,5. 2mT t n =+ .E5 = )/(69,1928,6..5,0 5 mT P = .

+ p lc t ch ng:

P6 = ( ) )/(90,1.5,006,4... 2mT t n aan =+ E6 = )/(81,406,5..5,0 6 mT P =

- Lp phng trnh cn bng mmen i vi im A: MA = E5.2,10 + E6.1,69 - N.6,28 = 0N = 7,88(T).

- Ta coi thanh chng ngang l 1 dm chu nn ng tm.- Chn tit din thanh chng:

F )(75,3210010.88,7 2

3

cm R N

a==

- Ta chn loi thanh chng I No24 c cc c trng sau:F = 34,8 cm2 ; ix = 9,97 cm ; iy = 2,37 cm

- mnh ca thanh:

x = 06,2097,92000 ==

xil

y = 38,8437,22000 ==

yil

Vy: max = max ( x ; y) = 84,38


+2 .2 m

+5 .7 m

3 , 5

2 , 2

2

E 1

E 2

E 3 E 4

E 5E 6


23/36


Tra bng ta c = 0,751- Cng thc kim tra n nh :

R F N

=

.

50,301751,0.8,34

10.88,7 3== (kG/cm2) < R = 2100 (Kg/cm2).

Vy iu kin n nh ca thanh chng c tha mn.* Xt giai on 2:

+ Tnh duyt cng cc vn thp- S tnh cc vn thp l dm gin n k ln 2 gi l thanh chng v im O ccmt trn ca lp b tng y i 0,5m v pha di

- p lc thy tnh : E1, E2- p lc ngang ch ng : E3, E4, E5- p lc ngang b ng : E6, E7- Momen gy lt (E1, E3, E4, E5) - Momen gi (E2, E6, E7)- Khi kim tra cng ca tit din cc vn thp, ta c th ly momen ln nht trocc vn thp l momen gy lt- Ta tnh E1, E3


+2.2m

+5.7m

3 , 5

2 , 2

2

E1

E2

E3 E4

E5E6


24/36


E1 =21 .(h 21 . n) = 10,04 (T/m)

E3 = ( ) 00,2..26,3..21 2 =

aan n (T/m)

Ta tnh VA, VB bng cch xp 2 ti trong E1 v E3 ln dm n gin v tnh bnhthng

-VA = 8,21 (T)- VB = 3,83 (T)

- Gi z l on cn tm momen t maxM z V z B .6

1 3 =

m z dz

dM 39,30 ==

Mmax = (VA.1,09 - E3.0,003 + E1.0,403).1 = 12,994(Tm)64,590

220010.994,12 5max

max === W M

(Kg/cm2) R u =2100 (Kg/cm2)

- Vy cc vn thp kh nng chu lc Ht nc h mng :- Sau khi btng bt y ta tin hnh ht nc thi cng b tr v thn tr.- Ht nc trong h mng ta s dng my bm ht- Lu lng nc y ch yu l nc c sn trong h mng v nc thm qua ckhe gia cc cc vn rt t coi nh khng c:

V = 4.9,2.4 = 147,2 m3.- Chn my bm C-665 c cc thng s:

+ Nng sut : Q = 120 m3/h. + su ht nc : 4 m

+ ng knh ng ht 100 mm.+ Cng sut ng c 6KW.

- Thi gian ht ht nc trong h mng :n =

147,2 1,22( )120

V h

Q= =

- Chn my bm v phi d tr thm 1 my bm bm nc t ngoi vo trong hmng phng s c- V tr t ng ht phi v tr thp nht ca h mng v phi lm h t nc.III. Thi cng b cc, thn trIII.1. Thi cng b cc:III.1.1. Trnh t thi cng:



25/36


- H mng c ht ht nc, tin hnh p u cc l ct thp ra ngoi v uct thp theo thit k.- Lp dng ct thp cho i cc.- Lp dng vn khun b cc.

- Tin hnh b tng.III.1.2. K thut b tng:- Btng c trn ti trm trn v vn chuyn n v tr btng.- Khi btng vn chuyn t trm trn n, cn phi kim tra cht lng ca bt( kim tra v st ) trc khi cho btng.- Btng c thng qua my bm btng. Chiu dy mi lp b tng 30cm.- B tng theo di nghing vi gc nghing = 2025o

III.1.3. Chn my m v my trn btng:- Dng m di c cc thng s k thut sau:+ u cng tc di: 40cm+ Bn knh nh hng: R = 70cm+ Bc di chuyn ca di khng qu 1,5.R = 1,05m+ Khi m lp trn phi cm vo lp di 10cm btng c lin

khi.- Chn my trn b tng:

+ Nng sut ca my trn: N = Vsx. f . nck . K tg

Trong :Vsx: dung tch sn xut ca thng trn, V = 1m3

f : h s xut liu, f = 0,7.K tg = 0,8 : h s s dng thi gian.

nck =ckt

360: s m trn c trong mt gi

tck = t1 + t2 + t3 .Trong :

t1: thi gian vt liu vo thng, t1 = 20(s)t2: thi gian trn vt liu, t2 = 150(s)t3: thi gian b tng ra, t3 = 20(s)nck = 19 (m trn/h).N = 1.0,7.19.0,8 = 10,64 (m3/h)

III.1.4. Tnh ton vn khun:



26/36


III.1.4.1. Cu to vn khun b tr:- S dng vn khun lp ghp bng thp c chiu dy 4mm- Kch thc b mng: 2,2x7,0x2,0 m- Cc np ng v ngang l cc thp hnh L80x80x8

- Cc thanh cng bng thp = 10 t ti v tr giao nhau gia np ng v np ngang.1.Tnh ton vn khun b cc :Kch thc b cc : ( 8 x 3 x 2 ) .Chn kch thc cc b phn ca vn khun :

VANKHUONSOI

2 0 0

100

III.1.4.2. Xc nh chiu cao ca lp btng tc dng ln vn khun:- Vn khun chu p lc ca b tng ti. Cng p lc ny c th thay i tron phm vi ln, ph thuc vo nhiu yu t khc nhau nh st ca b tng, trnlng ct liu, phng php v m b tng.- Trong qu trnh m cng p lc ngang ti vng nh hng ca m s tng ln.- p lc ca b tng ti thay i r rt khi thay i cng c v phng php mTrong qu trnh ng kt th p lc ca b tng s gim dn v sau mt thi gian btng hnh thnh cng th p lc s mt i hon ton. Song ng sut v bidng trong cc b phn ca vn khun do p lc ngang ca b tng ti gy ra vn gnguyn.- Hn hp b tng ti di tc dng ca m rung c cu to nh t ct bo hnc, khng c dnh kt. Chiu cao H ca biu p lc ngang ph thuc vo thgian ng kt v chiu cao ca lp b tng ti.



27/36


(a) (b) (c)p=f(t)

H =

4 h o

pmax1 pmax2

R

R q

H

q

(a): p lc btng gi nh(b): p lc btng khi khng m rung(c): p lc btng khi c m rung

- Tc tng chiu cao lp b tng vn khun ph thuc vo cng sut my trn v

din tch b tng. Thi gian ng kt ca b tng ph thuc vo cht lng xmng, cc tp cht ha hc, nhit khng kh v cc yu t khc. Khi tnh vn khuta ly thi gian ng kt l 4h k t lc trn. Nh vy chiu cao p lc l : H = 4h0.

Vi ho: Chiu cao ca lp b tng trong 1 gi 10,64 0,44

3.8o N

h m F

= = = (Dng 1 my trn btng)

Trong :F: din tch btng, F = 3.8 = 24 (m2)

N: Nng xut ca my trn b tng c dung tch thng trn 1m3; N=10,64 m3/hH = 4.ho = 4.0.44 = 1,76 (m)

III.1.4.3. Xc nh p lc ngang ca btng ti tc dng ln vn khun:- Hin nay b tng cc kt cu khc nhau u dng m rung khi hn hp btng ti nm trong vng tc ng ca m c nhng tnh cht gn vi tnh cht ccht lng c ngha l s lin kt gia cc phn t b ph v, hn hp b tng tronvng ny hon ton lng v gy ra mt p lc ngang ln vn khun ging nh p lcthy tnh ca nc.- p lc ca hn hp b tng pha di vng tc dng ca m ph thuc vo sv cc tnh cht khc ca hn hp, song tr s p lc ny khng th ln hn gi tr ci ca p lc b tng trong vng b tc ng ca dm.V th c th ly bng gi tcc i ni trn, khi b tng nhng kt cu ln hn hoc tng mng m dng th p lc ngang ca b tng ti c tnh theo cng thc:

Pmax = (q+ .R ).nTrong :



28/36


q = 200 KG/m2 : Lc xung kch khi b tng . = 2500 KG/m3 : Trng lng ring ca b tng . R = 0,7 m : Bn knh tc dng ca m . n = 1,3 : H s vt ti .

Pmax = (200+2500.0,7 ) .1,3 = 2535 (KG/m2).* Cc tm thp ca vn khun c tnh nh bn k 4 cnh ngm cng v m menun ln nht c tnh cho 1m rng bn.

Mmax= .Pmax.b2

Trong :Tra bng 2.1 sch thi cng cu ta c: = 0,0829

=0,0574 :H s ph thuc vo cc cnh a v b,2 21ab

= =

+ Pq: p lc ngang qui i trn chiu cao biu p lc.

H F

P al q =

Trong :Fal: Din tch biu p lc

( ) ( )R P q R H P F al ..21

. maxmax ++= (Xem hnh bn)

( ) ( ) 7,0.25352002

17,076,2.2535 ++=

=5767,35(kG/m)

5767,35 3453,5

1,76al

q

F P

H = = = (kG/m2) = 0,34(T/cm2)

Mmax = 0,0529.3453,5.12 = 29,98 (kG.m)- Mmen khng un ca 1m b rng tm thp bn:

Wx = )(17,46

5,0.100 32

cm=

- Kim tra cng ca thp bn:

u x

RW

M = maxmax

Trong :+ R u: l cng tnh ton ca thp khi chu un, R u = 2100(kG/cm2)

2100)/(10,71917,4

10.98,29 22

max= Vy iu kin v cng ca thp bn c tho mn.


q

R

H

Pmax


29/36


R

H

P*max

- Kim tra vng ca thp bn:

f =250

][.

..3

4'l

f E

b P qd =

(i vi mt bn)

Trong :+ P'qd : p lc quy i khng tnh lc xung kch

H F

P al qd '

' =

P ' max = .R = 2500.0,7 = 1750 (Kg/m2) ( )( ) 'max' ..2

1 P R H H F al += (xem hnh bn)

= 4217,5 (Kg/m)P 'qd = 10,152876,2

5,4217= (Kg/m2)

+ = 0,0162 : H s ph thuc t s a/b+ b = 50cm = 0,5m+ = 0,4cm l chiu dy ca thp bn.+ E l muyl n hi ca vn thp E = 2,1.106(kG/cm2)

=> f = cm115,04,0.10.1,2

0162,0.50.15281,036

4

=

[f] = cml 2,025050

250==

C: f = 0,115cm < [f] = 0,2cmVy iu kin v vng gia nhp ca bn thp c m bo. Kim ton kh nng chu lc ca thp sn ngang:

- Cc thp sn ngang c xem nh dm lin tc k trn cc gi l cc thp sn ng.- Thp sn ngang chu p lc btng ln nht trn c chiu di thanh thp. V vymmen un cc tit din ca n (trn 1m b rng) c xc nh theo cng thc:

M tt max = 21 ..1,0 a P q

Trong :+ a : Khong cch gia cc thp sn ng, a = 0,5m



30/362x0.5m

4 x 0 . 5 m


+ P1q : p lc ca btng phn b u trn thp sn ngangTa c H = 2,76 m > 1m nn :P1q = Pq. = 2089,62.1.0,5 = 1044,81 (Kg/m2)- Momen ln nht ti gia nhp:

Mttmax = 0,1.1044,81.0,52 = 26,12 Kg.mThp gc L80*80*8 c cc c trng hnh hc nh sau :

+ F = 12,3cm2

+ Jx = 72,2cm4

+ ix = 2,43cm+ Wx = 14,03cm3 + z=2,77 cm

- Kim tra iu kin v cng : u

x

RW

M = max

max

+ Ru: l cng tnh ton ca thp khi chu un: Ru = 2100(kG/cm2 )=> u RcmkG


31/36


- Din tch chu p lc ngang b tng ti ca thanh cng:F = 2.a.l=2.0,5.0,5 = 0,5(m2)

- Lc ko tc dng ln thanh cng:

T = Pq.F = 2,08962.0,5 = 1,045 (T)- Chn thanh cng 10 c Fa = 0,785(cm2); R o=1900(kG/cm2).- iu kin bn ca thanh cng:

)/(1900 20 cmkG R F T

a

==

=> 023

)/(21,1331785,0

10.045,1 Rcmkg


32/36


Trong qu trnh cn ch :- Khng lm sai lch v tr ct thp- Khng dng m di dch chuyn ngang b tng- B tng phi c lin tc cho n khi hon thnh,trnh hin tng phn

tng.

CHNG IITHI CNG NHP.

Cu gm 4 nhp btng ct thp ng sut trc dm T, mi nhp di 42m.

+4.0

+8.0

3 0 0 0 30 0 0

7006700

3 0 0 0

2 0 0 0

-21.5-18.8

-16.6

-19.5

-12.6

7 0 0 5

0 0

1000

1600

5 0 0

7 0 0

1600

2000

5 0 0

7 0 0

1600

2000

+0.2

1 9 0 0 0

L?PC?PPH?I?I20CM5050420005042000504200050

5 0 0

3000 3000

2 0 0 0

3000

2 0 0 0

3000

2 0 0 0

42000

3000

2 0 0 0

1500

+6.4

0.0

+2.0

+16.7

-6.0

+6.4

+2.2

300

42000 42000

M? A NH?P1 TR? 1 NH?P 2 TR? 2 NH?P3 TR? 4 NH?P4 MB

2 0 0

1500

5 0 0

300

L=19m

L=19m

L=19m

L=19mL=19m

II-III

I II-II

7 5 0 0

1 3 0 0 0

1 5 0 0 0

2 0 0 0

7 5 0 0

-2.5

+18.8

-0.5

+8.7+9.8

+0.6

-64

+4.7

-2.5

1500

L?PSTD?OC?NG

L?PCTL?NS?I

L?PCTH?TL?N

C?CD?NHU?NGVOC?UB?NGBTCT1/2 M?T C? T CHNH DI?N,T?L?:1/200 1/2 M? T C?T D? C C?U,T?L? 1/200

PHUONG N I:C? U BTCT UST (42+42+42+42)ML?PBTNH? ADY75MML?PPHNGNU?CDY0.4CML?PBT B?NM?TC?U

MNTT: +11.7

MNTN:+5.7

MNCN:+15.7

LANCAN

18C?C BTCT35X35 CM

21C?CBTCT35X35 CM

21C?C BTCT35X35CM21C?CBTCT35X35CM

21C?C BTCT35X35CM

L?PBTNH? ADY75MM

L?PC?P PH?IDAM20CM

I .I . iu kin a hnh - a cht thu vn: I.1. iu kin a hnh:

Do khu vc xy dng cu thuc khu vc h lu ca sng nn mt ct dc sntng i bng phng, xung quanh khu vc xy dng tp trung nhiu dn c.



33/36


I.2. iu kin a cht:a cht thy vn ti v tr tr s 3 gm 3 lp t nh sau :+ Lp 1 : St so cng+ Lp 2 : Ct ln si+ Lp 3 : Ct ht ln dy v cng- Cao mc nc thi cng l : +5,7 m.- Khu cu l : L0 = 163 m.

I I .I I . iu kin kh hu - thu vn: II.1. iu kin kh hu:

Khu vc xy dng tuyn thuc vng kh hu hay thay i, nhit trung bnhquanh nm khong 25oC. Vo ma h nhit cao nht c th ln ti 37oC.

Giai an t thng 2 ti thng 9 nng ko di, t c ma, nn thun li cho victhi cng cu.

Vo ma ng thng c gi ma ng bc lm nhit gim v thng c

ma ko di, nhit trung bnh 15-20o

C. m : 90%. Ngoi cc yu t ni trn cc u kin t nhin cn li khng nh hng nhin vic xy dng cu.

- Dn c ni xy dng cu c mt trung bnh. Hu ht nhn dn khu vc nylm nng nghip nn n v thi cng c thun li thu mn lao ng ti ch khi nnnhn thi cng nhng cng vic n gin, khng yu cu cao v k thut, gi thulao ng khng cao.

II.2. iu kin thu vn:Khu vc ny thuc h lu sng nn mc nc thay i t vo cc ma.

Cc s liu thu vn :- Mc nc cao nht : +15,7 m.- Mc nc thng thuyn : +11,7m.

- Mc nc thp nht : +5,7m. III. iu kin thi cng - tin hnh thi cng lao lp nhp th cc cng vic sau phi c tin hnh

hon chnh .- M tr cu c xy dng xong.- Dm c sn bi- Cc cu kin b tng t 100% cng

IV. ngh cc phng n



34/36


- Dm ta thi cng l loi dm b tng ct thp ng sut trc tit din ch Tchiu di 35(m),chiu cao 1,80(m).

- T iu kin a hnh a cht thy vn,chiu di trng lng kt cu,chicao tr ta a ra cc phng n sau:

- Lao lp dm bng gi long mn.- Lao lp dm bng t hp kiu mt tha loi ln.

Ni chung cc phng php trn v cc phng khc u c th thi cng u c Nhng chng c nhng nhc im rt ln m qu trnh thi cng ta hay gp phi.

-Phn n I: Lao lp dm bng gi long mn:Dng hai cn trc long mn di chuyn dc trn cu tm. Cu tm c cc tr

c k trn cc r . Dm c vn chuyn bng xe gong n trc gi long mri c nng ln bng h thng palng xch v vn chuyn ngang h xung v tr gCh khng c nng ti khi cn trc di chuyn

u, nhc im :Dng cn trc long mn th cu lp c cu kin nng, cao ln.Nhn

nhc im thi gian lp rp lu.Hn na v iu kin a cht v tr cao nn thi githi cng rt lu v tn km.Vic xy dng tr tm cng lm tng chi ph,thi gian thcng m n nh v tnh an ton khng cao .


ROA

CU TAM

GIALONG MN

DM ANG LAO

TRUTAM


35/36


Phng n 2 :

Lao lp dm bng t hp kiu mt thaloi ln:T hp gm dn lin tc, u hng c kch rng iu chnh vng ca gin clao t b ra. Sau khi c nh cc u ca gin mt tha, ta tin hnh vn chuyndmb tng ct thp d ng lc t b ra bng xe gong. Khi phin dm b tng n vtr, dng rng rc v pa-lng xch nng dm ln v vn chuyn dm ra, ri sau adm sang ngang h xung gi. Mun gin n nh khi ko sang nhp khc cn c phi t i trng. Sau khi lp ht cc dm trong nhp, ta li tin hnh cc bc nhtrn.

NG RAY

DA N CHU

DA M B TC T HNG DI CHUYEN CUA D AM

S ODUNG DAN CHNH L AP DAM BTCT

35.0

2.0 2.0

I I

II



36/36


5 . 0

2 . 8

5.6

0 . 5

PA LANGDAM NGANG MUT THA

TAVET GO(15x20x200 Cm)

XE GOONGCHDAM

DAN CHULAO DAM

RAY THEP

T hp mt tha c lp rp trn b nn c th rt ngn thi gian thicng,vic lao gin cng tng i d dng, nhanh chng. Kt cu nh hnh, tnh lng cao rt thch hp cho vic thi cng cu nhiu nhp c chiu di nhp bng nhau.

Dm c xe goong ch n v a ra n v tr mc dm pha ngoi, tin hnh mc dm xung v mc vo dm.lc ny khng nng dm ln m di chuyn dmcn lao theo phng dc, pha sau l dm di chuyn trn xe goong bng h thng coln . Sau khi dm di chuyn gn n v tr mc dm pha sau ta dng h thng khncho dm chy theo phng dc na m cho mc dm h xung v mc dm. Lc nta mi nng dm ln v h thng di chuyn mc dm bt u di chuyn cng lc va dm ra n v tr cn t .Sau ta dng h thng h dm xung v t d

xung .H thng nng h dm c th di chuyn trn dn ch theo phng dc vngang cu a dm n v tr cn t . Kt lun:

T vic so snh cc phng n v mt kinh t - k thut, cng nh nhng aton trong qu trnh thi cng ta chn phng n thi cng l phng n II (lao lp dm bng t hp mt tha loi ln)

Thi cng nhp s 1 :Cng tc lao cu lp ghp gm 2 giai on chnh :

Giai on 1 :Chun b hin trng nh dn gio, bi c dm, ng vn chuyn v sa chacc sai lch, lp th kim tra h thng kch ti, pa lng ko cn trc .

Giai on 2 :B tr cc gi lp buc v cu dm, lao lp cc phin dm vo v tr cn trc hocgi lao, iu chnh v lin kt cc mi ni, hon thin mt ng trn cu .

Documents

do an hiep