- May dao gau thu~ thich hgp kh6i dao cao hon m?tbdng may dUng va nang sudt cao.
lOOO.k, Trong do:
q- dung Hch gau; (lit).
n- s6 gau xa dAttrong I phUt ~- h~ s6 lam dAy gau.
k'g- h~ s6 thiJi gian su d\lIlg may.
k, - h~ s6 toi x6p Cila dAt (xem bang 1-2).
4.3.MAy nAo -CHUYEN nAT
May dao chuy€n dAt la nhUng may trong qila trinh di chuy€n d6ng thiJi cAt dAt thanh tirilg lap va mang dAt da den nm cful san lAp
4.3.1 May ui
May iii la m(lt trong nhUng 10(limaychil yeu trong cong mc thi c(lng dAtacac cong trinh giao thong, thuy IQ'i,thuy di~n, hAm mo v. v... May iii co th€ lam vi~c d(lc I~p hay ph6i hQ'PciJng veri cac may thi cong khac d8 thi cong cong trinh. Khi lam vi~c m(lt minh no co nhi~m Y\I: san bfutg, iii nhUng go d&tcao, I&ph6 va chuy€n d&tthila di nm khac, dAp d&tn8n cao til 1.0 den 1.5m, dao h6 dao ranh boc lap phil th\lc v~t, ...
1. ciu ttlO va cling dyng: a. cAu ttlo: (Hinh 4.17)
Theo ca c&u luai ben va kha nang thay dbi vi tri Cila lum ta co hal 10(limay iii: 10(li may iii thucrng co lum va khung lAp c6 dinh; 10(li may iii Vl;lDnang co co c&u lum ben va khung day khong c6 dinh, cae may iii Vl;lDnang lAp ben thfutg goc vai huang ehuy8n d(lng
Clla may keo va di~u chinh cac goc c~t cua lucri nhu may ui khong quay. Ngoai ra may ui
V(Ul nang con co kha nang quay lum ben atrong hai m(it ph~g: m(it ph~g ngang va m(it p~g th~g dUng.
b. May iii co ban iii ca djnh
Khi lam vi~c d(ic lip may iii lam dUV'ccac nhi~m VI} sau:
_ San nhiing go dAt cao, san lApcac ao hf>va chuy~n dAt thua dinai khac. _ D~p n~n cong trinh co dQ cao tU 1+1,Sm b~g cach lAytu hai ben d~ d~p.
_ Dao h6 mong cong trinh, dao d~p kenh muong, hOc lap dAt phong hoa, v~ chuy~n dAttrong c\lly ng~ 10+ 100 m.
Kbi may iii phai hQ'P cung vOi cac IO\limay thi cong khac:
_ Ph6i hgp vm may c~p: Tang cuang l\lc dAy d~ tang nang suM dao cho may c~p, sua duang cho may c~p thi congo ..
- Ph6i hgp vm may xuc: May ui lam nhi~m V\I dQn m(it b~g, sua khoang dao cho may xuc.
- Ph6i hgp vm may dfun dAt: May ui san b~g nhiing d6ng dAt mm db dung vcri dQ day theo yeu cAu d~ may dfun lam nhi~m V\I dfun nen dAt.
- Ph6i hgp vm oto: May iii lam duang di I~ cho 0 to ~ cong truang V.V.
c. May iii co ban iii quay
, \ 2 9) 1 S i .2 C) 'LL ri :~~rLa J[~J~---\ i ~ - - --' '. Jll . ~ . -b =! 1'- \ ..• ---- '_J.. 12 oJ"-
Binh4.17: May tii
1-Kh6p n<\i; 2.3. Clmg d~y; 4. Dao cllt; 5. Luai tii; 6. Thanh giiing; 7, Xylanh thuy I\l'c; 8. May keo; 9. Kh6p; 10. Thanh d~y; 11. Xylanh thuy I\l'c; 12. Kh6p c~n;
Hlnh4.18: Sodlic:lu410may iii co ban iii coc djnb va lucrixm ddt 1. Lum iii; 2. Khung iii; 3. Xilanh thiiy 1\fCdiiu ehinh goe cAt
4. xilanh thily llfCnang hll b(\ cong taciii;5. B(\ lucrix&i. 3. Tinh nang suAt va bi~n phap nang eao nang suAt eho may ui:
a. Tinh nang sudt eiia may iii:
Nang suAt ella may iii duge xae dinh theo eong thUe sau: 3600.V.kd.k,g 3
Q=----(m ih) (4.4)
Tck
Trong do:
V: th8 tieh kh6i dAt tru&e lucri ben eua m(\t ehu ky lam vi~e; (m3)
V = L.H' (m3) (4.5)
2tg<Po.k,
L: ehi8u dai lucri ben; (m) H: ehi8u eao lucri ben; (m)
<po:-goe ehay tv nhien eua kh6i dAttru&e lucri ben khi ui (<Po'"450); (d(\) k1: h~ s6 tai eua dAt; (xem bang (1- 2) aphfut may dao) .
. kd: h~ s6 ph\l thu(\e vao dia hinh.
ktg: h~ s6 thai gian sir d\lllg may; (thuang lAy ktg = 0,75+0,85) Tek: thai gian thve hi~n m(\t ehu kY lam vi~e eua may; (s).
Tck =tt +t, +to +te +th +2t (s) (4.6) tl = ~: thai gian dao; (s)
VI
t, = ~: thai gian ehuy8n ddt; (s)
v,
10 ,.. .., > •
to = -: thm glan lUIve eho dao; (s)
Vo
th: thm gian h~ lum ben (1h"" 1,5+2,5); (s) t: thm gian rmiy quay d~u (t "" 10); (s)
h, h, 10:I~ lugt chi~u diti quang duimg dito, v~ chuy~n,vit trcr v~ ch6 dito,
0,60 1,70 15% 0,70 1,50 10% 6% 0,85 1,20 3% 0,90 1,10 < 2% 1,00 1,00
VI, V2, Vo: V~ t6c tu<mg img vo; cac quang duimg tren; (mls).
Bang tra h~ s6 ph\' thuqc dia hinh k.J:
DQ
k.!
Vi len doc
Vi xuongdoc (m).
b. Bi~n phap nang cao nang suit:
3600.V .kd.ktg• •
Qua clIng thuc Q = ----~ ta thay, nang suat cua may ui ph\! thu(jc vito cac Tck = 3,95 m = 1,15 m = 5,4km1gicr. = 9,0 kmlgicr. = 10;8 km/gicr. = IS m. =60m. =2 (s); =4 (s); dq.i Im;mg:
- Th~ tich kh6i d&ttruac lucri ben cua m(jt chu ky litm vi~c (V); - H~ s6 ph\! thuQc vito dja hinh (k.,);
- H~ s6 thm gian su d\lDg may (ktg);
- Thm gian th\fc hi~n mQt chu ky litm vi~c cua may (Tck).
Do v~y mu6n nang cao nang su&t cua may ui c~ pMi tang (V); B6 tri thi clIng hgp Iy vo; dja hinh co l(1inh&t d~ chQn dU(1ch~ s6 (kd) Ian nh&t; T~n d\lDg t6i da thiri gian hi~u ich litm vi~c Clla may, d~ tang h~ s6 (ktg) vit giitm (Tck).
4. Vidlp
DUng lo~i may ui CATERPILLAR-D5C-(5P) d~ thi cong san ui cho m(jt cong trinh
Yiiu cdu:
Tinh nang su&tcua may ui tren, cho bi~t cac thong s6 ky thu~t cua may ui vit cac di~u ki~n khac nhu sau:
- Chi~u dill lum ben: L
- Chi~u cao lum ben: H
- V~ t6c khi may dito d&t: VI
- V~ t6c khi may v~ chuy~n d&t: V2
- V~ t6c khi may khong v~ chuy~n d&t: Vo
- Quang duimg may dito d&t: h
- Quang duimg may v~ chuy~n d&t: h
- Thm gian nang hq.lum ben: th
- Thm gian sang s6: tc
- Goc cMy t\f nhien cua kh6i d&ttruac lum ben khi ui: <po= 450
- Cac h~ s6 khac: kt= 1,20; kd = 1,50; ktg= 0,80. - May ui chq.y theo sad5 ti~n lui
Nang sufit Clla may ui dugc xac djnh theo cong thuc: 3600.V.kd.k,g 3