31TCXDVN 285_2002 quy dinh ve thiet ke CT thuyloi

8/7/2019 31TCXDVN 285_2002 quy dinh ve thiet ke CT thuyloi

1/35

TCXDVN TIU CHUN XY DNG VIT NAM

TCXDVN 285 : 2002

CNG TRNH THU LI

CC QUY NH CH YU V THIT K

H ni - 2002

LI NI U

Tiu chun xy dng Vit Nam TCXDVN 285 : 2002 - Cng trnhthu li - Cc quy nh ch yu v thit kdo B Nng nghip vpht trin Nng thn t chc bin son, V Khoa hc Cng ngh trnhduyt, B Xy Dng ban hnh theo Quyt nh s 26 /2002/Q-BXD ngy28 thng 8 nm 2002.

1


2/35

1. Phm vi p dng1.1. Tiu chun ny bao gm cc quy nh ch yu v thit k cn phi p dng khi lp,thm nh, xt duyt cc D n thy li, bao gm: D n quy hoch, D n u t (Boco nghin cu tin kh thi, Bo co nghin cu kh thi hoc Bo co u t), Thit kxy dng cng trnh (Thit k k thut, Thit k bn v thi cng hoc Thit k k thut-thi

cng). Tiu chun ny thay th TCVN 5060-90 - Cng trnh thu li - Cc quy nh ch yuv thit k.1.2. Thit k , b bao, cng trnh giao thng thu, cng trnh bin khng thuc phm viiu chnh ca tiu chun ny.1.3. Tiu chun ny p dng cho mi D n thy li thc hin trn lnh th Vit Nam,thuc mi loi hnh: xy dng mi, sa cha, phc hi, nng cp hoc m rng; khngphn bit ngun vn. Ch c php p dng nhng tiu chun khc vi tiu chun nykhi c s chp thun ca C quan qun l Nh nc c thm quyn.1.4. Khi nghin cu, thit k cc cng trnh thy li ngoi vic tun th nhng quy nhch yu nu trong tiu chun ny cn phi tun th cc quy nh trong cc Lut, cc vn

bn di Lut, cc tiu chun TCVN, TCXD, TCXDVN, TCN, cc iu c quc t v cctha thun m nh nc Vit Nam tham gia hoc k kt c lin quan n i tngthy li ang xem xt.2. Thut ngha, Phn loi v phn cp thit k cng trnh thy li

2.1. Gii thch mt s thut ng.- Tt c cc cng vic "nghin cu, thit k" nu trong iu 1.1 c vit gn l "thitk".- Tt c cc i tng nghin cu, thit k thy li nu trong iu 1.1 c gi chung l"D n thy li".- Nhng hng mc xy dng c th trong D n thy li nh p, cng, nh my thyin, knh dn nc v.v... c gi chung l "Cng trnh thy".- Cm t"Cng trnh thy li" trong tiu chun ny l tp hp tt c cc hng mccng trnh thy c trong D n thu li.- Cm u mi cng trnh thu li l mt t hp cc hng mc cng trnh thu tp trung v tr khi u ca h thng dn, thot nc; lm chc nng cp hoc thot nc, iutit, khng ch, phn phi nc.- H thng dn, thot nc l t hp mng li ng dn v cng trnh lin quan c mttrong d n.- Theo thi gian s dng, cng trnh thy trong cc D n thy li c chia thnh cng

trnh lu di v cng trnh tm thi:+ Cng trnh lu di l cng trnh c s dng thng xuyn hoc nh k trongsut qu trnh khai thc.+ Cng trnh tm thi l cng trnh ch s dng trong thi k xy dng hoc chdng sa cha cng trnh lu di trong thi k khai thc ( quy, cng trnhdn, x lu lng thi cng, cu tm v.v...).

2.2. Ty thuc vo chc nng, cng trnh lu di c chia thnh cng trnh ch yu vcng trnh th yu:

a. Cng trnh ch yu l cng trnh m s h hng ca chng s nh hng trc tip ns lm vic bnh thng ca cng trnh u mi v h thng, lm cho chng khng mnhn c nhim v nh thit k t ra.

2


3/35

b. Cng trnh th yu l cng trnh m s h hng ca chng khng nh hng n slm vic bnh thng ca cng trnh u mi v h thng, c th phc hi c trong mtthi gian ngn.

Danh mc cng trnh ch yu v cng trnh th yu qui nh Ph lc A.

2.3. Cng trnh thy li c phn thnh 5 cp thit k tu thuc vo quy m, a im

xy dng cng trnh, mc nh hng tch cc ca chng n pht trin kinh t x hi,an ninh, quc phng v.v... cng nh tc ng tiu cc n ti nguyn, mi trng, tntht v ngi v ti sn do s c ri ro c th gy ra. S khc nhau ca mi cp thit kc th hin bng h s an ton chung ca cng trnh v cc qui nh v kho st thitk. Cng trnh cp I c h s an ton chung ln nht v gim dn nhng cp thp hn.

2.4. Cp thit k ca cng trnh u mi, bao gm c cng trnh u mi trong khai thcbc thang l cp cao nht c la chn t cp xc nh theo nng lc phc v ca chnhu mi hoc t cp xc nh theo c tnh k thut ca cc hng mc cng trnh thyc mt trong cng trnh u mi:

a. Cp theo nng lc phc v c xc nh theo bng 2.1.

b. Cp theo c tnh k thut ca cc hng mc cng trnh thy trong cm u mi cxc nh theo bng 2.2.

2.5. Cp thit k ca h thng dn nc v cng trnh trn h thng dn nc cng lcp cao nht c la chn t cp xc nh theo nng lc phc v ca chnh on dnnc hoc t cp xc nh theo c tnh k thut ca cc hng mc cng trnh thy cmt trong on dn nc.

2.6. Cp thit k ca cng trnh u mi thng c xem l cp thit k ca cng trnhthy li. Cp thit k ca h thng dn nc v cng trnh lin quan thng bng hocnh hn cp thit k ca cng trnh u mi v gim dn theo s thu hp phm vi phcv. V nguyn tc, cp thit k ca knh dn nc cp di phi ly nh hn cp thit kca knh dn nc cp trn.

Bng 2.1. Cp thit k ca cng trnh theo nng lc phc v

Loi cng trnh thy li Cp thit k

I II III IV V

1. H thng thy nng c din tchc ti hoc din tch t nhinkhu tiu, 103ha

50


4/35


5/35

b. Cc cng trnh thy cp I v II khng nm trong tuyn chu p (tr nh my thu in,ng ng dn nc c p, ng dn nc vo tucbin, b p lc v thp iu p).

c. Cc cng trnh thy trong cm nng lng, h thng ti tiu nng nghip c th tinhnh tu b sa cha cng trnh m khng lm nh hng ng k n s lm vic bnhthng ca u mi thy li.

2.8. Cp thit k ca cng trnh thy li cn nng ln mt cp nu s c ri ro ca cngtrnh dng nc, tch nc c th gy thit hi to ln v ngi- vt cht- mi trng, dnn thm ha cho cc khu dn c, khu cng nghip, cc h cha hin c, cc tuyn giaothng huyt mch nm h lu v.v...

Nhng p xy dng bng vt liu ti ch trn nn st yu bo ho nc trng thi dochy, chy c php nng ln mt cp so vi quy nh trong bng 2.2.

2.9. Cc cng trnh xy dng thuc chuyn ngnh khc c mt trong thnh phn ca Dn thu li hoc cc cng trnh thy thit k c s giao ct vi cc cng trnh khc hinc (ng b, ng st v.v...), khi xc nh cp thit k cn phi i chiu vi cc tiu

chun lin quan v c s ng thun vi c quan ch qun cc cng trnh .

2.10. Cp thit k ca cng trnh thu giao ct bo v phng l c xc nh nh cpca cng trnh chu p (Bng 2.2) nhng khng c php thp hn cp thit k v tiuchun an ton ca tuyn .

2.11. Vic xc nh cp thit k cng trnh thu li theo bng 2.1 v 2.2 cng nh vic xut nng hoc h cp u phi gii trnh da trn nhng lun c xc ng trnh ln cpph duyt D n quyt nh.

2.12. Nhng cng trnh thu li cp I c c im nu iu 2.8 hoc c vai tr thencht trong pht trin kinh t ca khu vc, hoc nh hng trc tip n an ton x hi (lngun cp nc chnh, ngun nng lng ch o, cng trnh gim, phng l cho h luv.v...), hoc xy dng vng c iu kin t nhin khng thun li (vng c bo lt ln,vng c iu kin nn mng phc tp, vng c ng t ln v.v...) nu thy cn thit, cquan thit k phi kin ngh xy dng Tiu chun thit k ring cho mt phn hoc tonb cng trnh ny.

2.13. Quan h cp thit k gia cng trnh ch yu - cng trnh th yu - cng trnh tmthi trong mt cng trnh u mi hoc h thng dn c qui nh trong bng 2.3.

Bng 2.3. Quan h cp thit k gia cng trnh ch yu - cng trnh th yu -cng trnh tm thi trong mt cng trnh u mi hoc h thng dn

Cp thit k ca cng trnh umi hoc h thng dn I II III IV V

Cp thit k cng trnh ch yu I II III IV V

Cp thit k cng trnh th yu III III IV V V

Cp thit k cng trnh tm thi IV IV V V V

2.14. Cp thit k ca cng trnh tm thi c th c nng ln mt cp khi s h hngca chng dn n cc hu qu sau:

5


6/35

a. C th gy ra thm ha cho cc khu dn c, khu cng nghip tp trung, cc tuyn giaothng huyt mch h lu.

b. Lm mt an ton cho cng trnh lu di ang xy dng.

c. Thit hi v vt cht gy ra khi s c ln hn nhiu so vi vn u t thm cho cngtrnh tm thi.

d. y li thi gian a cng trnh vo khai thc, lm gim ng k hiu qu u t.

3. Nhng yu cu ch yu v thit k cng trnh thy li

3.1. Khi lp D n thy li phi cn c vo mc tiu pht trin kinh t x hi ca tngthi k (ngn hn, trung hn v di hn) c hoch nh trong k hoch pht trinquc gia - vng lnh th, k hoch pht trin ca cc ngnh v quy hoch khai thc luvc nhm xut phng n khai thc v s dng ti nguyn nc mt cch hp l nht.

3.2. Vic la chn trnh t khai thc bc thang, quy m cng trnh, hnh loi cng trnh,

b tr tng th, cc thng s chnh cng nh cc mc nc tnh ton in hnh cn phic quyt nh trn c s so snh cc ch tiu kinh t - k thut gia cc phng n vc xt ti:

a. a im xy dng cng trnh, cc iu kin t nhin trong vng chu nh hng caD n (iu kin kh hu, thy vn, a hnh, a cht cng trnh, a cht thy vn, tnkin to, mi trng sinh thi v.v...).

b. Nhu cu hin ti v tng lai cho ti tiu, cung cp nc, phng chng l, nng lng,vn ti thy, cng nghip, du lch v.v... c lin quan n ngun nc ca lu vc angxem xt.

c. D bo v s thay i ch thy vn, ch l thng h lu sau khi xy dngcng trnh c xt n k hoch m thm cc cng trnh hoc h dng nc mi trn luvc trong tng lai; D bo din bin lng dn, b sng, bi sng, b h, vng ca sng,vng ngp v bn ngp; S thay i ch lng ng bi xi bn ct thng, h lu;nh gi v xut bin php hn ch cc tc ng bt li.

d. Khi xy dng cc h cha cn phn tch nh gi nhng tc ng bt li sau y:

- Nhng thit hi vt cht do ngp gy ra: mt t c bit l t nng nghip, cc khubo tn thin nhin, rng c dng, ti nguyn khong sn, c s vt cht kinh t- x hi-vn ho v s mt i cc a danh lch s, cc danh lam thng cnh.

- Nguy c dn n vic thu hp hoc lm mt i nhng vng dn c sinh sng lu i;nhng bt li v an ninh- x hi- dn tc- quc phng, hu qu do v p c th gy ra.

- Tnh kh thi v iu kin tin cy ca cng tc di dn ti nh c m bo s hn hn vmi mt ca ni mi.

- Vng chu nh hng h lu h cha do s thay i dng chy, bn ct v.v... d botc ng ca chng n lng dn, k, vng ca sng; nh gi li ch kinh t x hisau khi xy dng cng trnh.

e. S bin ng mc tiu, nng lc v iu kin hot ng ca cc ngnh hng li hin

c khi cng trnh thy li mi i vo hot ng nh: vn ti thy, ngh c, ngh rng, cccng trnh thy nng, thy in, iu, cc cng trnh cp nc khc v.v...

6


7/35

f. Cc bin php bo m cht lng nc: dn lng h, ch v sinh thch ng vngquanh h cha, hn ch xm nhp cc cht c hi thng qua vic kim sot hm lngc hi khng vt qu tiu chun cho php.

g. Nhng iu kin khai thc tm thi v lu di ca cng trnh.

h. Nhng iu kin v phng php thi cng; kh nng cung ng lao ng, vt t, thit b

v ngun lc t nhin phc v xy dng.

i. S hi ha v kin trc, thm m ca bn thn cng trnh v s ho nhp ca chng vimi trng khu vc; Duy tr cc iu kin bo v thin nhin, cnh quan, v sinh mitrng sinh thi; Kh nng kt hp to thnh im du lch, an dng.

3.3. Khi thit k cng trnh thy li phi t c cc yu cu c bn sau:

a. bn vng ca cng trnh v tho mn nhng iu kin khai thc i hi phi png; Qun l vn hnh thun li, an ton; C gii php gim nh nhng tc ng bt ligy ra cho bn thn cng trnh v cc i tng b nh hng khc.

b. Gim st thng xuyn tnh trng cng trnh v trang thit b trong thi gian thi cngcng nh trong sut qu trnh khai thc sau ny.

c. B cc kin trc cc cm cng trnh u mi ph hp vi cnh quan xung quanh vkin trc c trng ca khu vc.

d. S dng vt liu ti ch mc ti a c th.

e. Bin php thi cng ti u, thi gian xy dng hp l ph hp vi lch khai thc sinh li,kh nng ca trang thit b hin c v cung ng vt liu xy dng; Kt hp gia c gii vth cng mt cch hp l.

g. T chc dn lng h v vng k cn; t chc n b di dn ti nh c v di di cc cs vt cht kinh t; Bo v nhng cng trnh kin trc vn ha lch s c gi tr trongvng ngp.

h. Tn dng khai thc hoc bo v cc m c ch trong lng h; Bo tn t nng nghipc gi tr mc cao nht c th; T chc bo v ngun thy sn.

i. Nhng iu kin cn thit p ng cho giao thng thy.

k. Cung cp lu lng cn thit cng nh m bo ch vn tc, mc nc thun licho cc h dng nc hin c v mi trng sinh thi h lu.

l. Cc bin php v phng tin bo m an ton khi thi cng v khai thc sau ny.

3.4. Khi thit k cng trnh thy li phi xem xt kh nng v tnh hp l v kinh t kthut trn cc mt:

a. Kh nng kt hp mt s chc nng trong mt hng mc cng trnh. C k hoch acng trnh vo khai thc tng phn nhm pht huy hiu qu kp thi.

b. C cu li cc cng trnh hin c v xut cc gii php ci to, khc phc chngph hp khi D n mi i vo hot ng.

c. Quy chun ho b tr thit b, kt cu, kch thc v phng php thi cng xy lpnhm y nhanh tin , h gi thnh v to thun li cho qun l sau ny.

d. Tn dng u nc c to ra cc u mi thy li pht in v cho cc mcch khc.

7


8/35

3.5. Cn phi nh gi tc ng mi trng v thit k tng th bin php bo v trn cs d bo s thay i ca chng sau khi hnh thnh h thng thy li.

3.6. Khi thit k cc cng trnh thy ch yu cp I, II v III phi b tr thit b kim tra- olng quan trc s lm vic ca cng trnh v nn trong sut qu trnh xy dng vkhai thc nhm nh gi bn vng ca cng trnh, pht hin kp thi nhng h hng

khuyt tt quyt nh bin php sa cha, phng nga s c v ci thin iu kinkhai thc.

Khi c lun chng tha ng, c th khng t thit b kim tra- o lng trong cng trnhcp III hoc ngh b tr thit b cho cng trnh cp IV.

3.7. Khi thit k cng trnh thy cp I, II cn phi tin hnh mt s nghin cu thcnghim i chng, hiu chnh, chnh xc ho cc thng s k thut v tng thm tin cy cho n nh: cc nghin cu v nn, vt liu xy dng, ch thy lc, ch thm, tnh trng lm vic ca cc kt cu phc tp, ch nhit trong b tng, ch lm vic ca thit b, hiu qu ca vic ng dng tin b khoa hc v cng ngh mi

v.v... i tng v phm vi nghin cu ty thuc vo iu kin c th ca tng cng trnhv c xut ngay trong giai on lp Bo co nghin cu kh thi. Cng tc ny cngc php thc hin cho hng mc cng trnh cp di khi c lun chng cn thit.

3.8. Khi thit k cc cng trnh thy dng khi ln phi tnh n vic phn b hp l vtliu trong thn cng trnh, ph hp vi trng thi ng sut, bin dng, yu cu chngthm v.v... nhm gim gi thnh m vn m bo c cc yu cu k thut.

3.9. Cc cng trnh thy phi m bo cc tiu chun v n nh, bn, khng chophp nt hoc hn ch m rng vt nt, bin dng ca cng trnh v nn trong miiu kin lm vic. ng thi phi tha mn cc yu cu gii hn v tnh thm nc, tc

ng xm thc ha hc, c hc ca nc, bn ct v cc vt tri ni; tc ng xi ngmtrong thn v nn cng trnh; tc ng ca sinh vt v thc vt v.v...

3.10. Khi thit k sa cha, phc hi, nng cp v m rng cng trnh cn p ng thmnhng yu cu sau:

a. Xc nh r mc tiu sa cha, phc hi, nng cp, m rng cng trnh, c th l:

- Sa cha cng trnh hot ng bnh thng hoc ko di thi gian hot ng trn cs cng trnh hin ti.

- Nng cp cng trnh, trang thit b nhm ci thin iu kin vn hnh, qun l, tngmc bo m, hoc ci thin mi trng hoc m rng nng lc phc v v.v...

b. Trong thi gian tin hnh ci to, nng cp cng trnh v nguyn tc khng c gyra nhng nh hng qu bt li cho cc h ang dng nc. Cn nghin cu s dng licng trnh c mc ti a.

c. Cn thu thp y cc ti liu kho st, thit k, thi cng, qun l, quan trc, s c xy ra ca cng trnh c, kt hp vi cc nghin cu kho st chuyn ngnh nhgi ng cht lng, tnh trng k thut, trang thit b, nn v cng trnh, lm c s chovic la chn cc gii php k thut.

8


9/35

4. Cc ch tiu thit k chnh4.1. Mc bo m ca cng trnh thy li phc v cho cc ngnh kinh t quc dn cxc nh theo bng 4.1.

Bng 4.1. Mc bo m thit k ca cng trnh thy li

i tngphc v cacng trnh

Mc bo m (%) theocp cng trnh

Ch thchI II III IV V

1. Ti rung

75 75 75 75 75 - C th nng mc bo m ti ln trn75% cho nhng vng c lng nc ngun

phong ph, vng chuyn canh mang lihiu qu kinh t cao khi c lun chng tincy nhng phi c c quan ph duyt Dn chp nhn.

2. Tiu chonng nghip

80 90

- Tn sut bo m ca h thng tiu phthuc quy m ca h thng, dng cngtrnh (t chy hay ng lc), kh nng tipnhn nc ca sng bn ngoi, hiu quu t ca h thng tiu.v.v. do c quanthit k lun c v ngh.

1. 3. Phtin

a) H c lp

90

90

85

80

80

- Mc gim st cng sut, in lng,thi gian b nh hng trong nm (hoc

ma) khi xy ra thiu nc ph thuc vov tr m nhn ca nh my thy introng h thng nng lng do ch u tn nh v cp cho c quan thit k

b) H s dngnc ti pht in

Theo ch tI - Khi nc dng cho pht in v ti trongngy c s chnh lch, cn phi lm thmh iu tit ngy m iu tit li.

4. Cp nc a) Khng chophp gin

on hocgim yu cucp nc

95

95

95

95

95 - Lu lng cp tnh ton c th l lulng ln nht, lu lng trung bnh ngy

hoc trung bnh thng v.v... do ch u tn nh v cp cho c quan thit k.

9


10/35

b) Khng chophp ginon nhngc phpgim yu cucp nc

90

90

90

90

90- Mc thiu nc, thi gian cho phpgin on cp nc cn cn c vo yucu c th ca h dng nc do ch u tn nh v cp cho c quan thit k.

c) Cho phpgin onthi gianngn v gimyu cu cpnc

80

80

80

80

80

Ch thch:

1. Mc bo m phc v ca cng trnh l s nm lm vic m bo cng sut thit k (ringthu in l cng sut bo m) trong chui 100 nm khai thc lin tc.

2. Vic tng hoc h mc bo m ch c php khi c lun chng chc chn v do c quanph duyt D n quyt nh.

3. Khi vic ly nc (hoc tiu nc) gy nh hng xu n nhng h dng nc hoc dn sinh,mi trng hin c, c quan lp D n cn c lun chng v cc nh hng ny, nu gii phpkhc phc v lm sng t tnh u vit khi c thm D n mi trnh ln c quan ph duyt vcc ngnh ch qun c cc i tng b nh hng cng xem xt v quyt nh.

4. Cng trnh a mc tiu phi thit k sao cho mc bo m ca tng mc tiu phc v ph hp

vi tiu chun nu trong bng ny.

4.2. Cc ch tiu thit k chnh v dng chy

Khi xc nh cc ch tiu chnh v dng chy bng s liu thng k hoc tnh ton, cn dbo kh nng din bin ca cc ch tiu trong tng lai sau xy dng: do iu kin tnhin ca lu vc thay i, do k hoch khai thc tip theo dng chy trn lu vc, do s

pht trin dn sinh kinh t ca vng v.v... c gii php k thut v quyt nh ng nnhm m bo an ton cho cng trnh, ko di thi gian phc v v tit kim vn:

a. i vi cng trnh cp V III thi gian cn d bo khng t hn 20 nm.b. i vi cng trnh cp II I thi gian cn d bo khng t hn 30 nm.

4.2.1. Lu lng, mc nc ln nht tnh ton thit k v kim tra n nh, kt cu,nn mng, nng lc x nc ca cc cng trnh thy li trn sng v ven b, cc cngtrnh trn tuyn chu p, cc cng trnh trong h thng ti tiu khi pha thng nguncha c cng trnh iu tit dng chy c xc nh theo bng 4.2.

Bng 4.2. Lu lng, mc nc ln nht thit k v kim tra cng trnh thy

Loi cng trnh thyCp thit k

I II III IV V

1. Cm u mi cc loi (tr cng trnh umi vng triu); H thng dn - thot ncv cc cng trnh lin quan khng thuc hthng ti tiu nng nghip; Cng trnh dn- tho nc qua sng sui ca h thng titiu nng nghip

-- Tn sut thit k

%0,1 0,2*(1000

500)

0,5(200)

1(100)

1,5(67)

2(50)

10


11/35

(Tng ng vi chu k lp li, nm)

- Tn sut kim tra %


0,02 0,04*(50002500)

0,1

(1000)

0,2

(500)

0,5

(200)

2. Cng trnh u mi vng triu; Cng trnh

v h thng dn thot lin quan trong hthng ti tiu nng nghip (tr cng trnhdn - tho nc qua sng sui ni im1)

- - Tn sut thit k%


0,2

(500)

0,5

(200)

1

(100)

1,5

(67)

2

(50)

Ch thch: * Tn sut nh p dng cho cc cng trnh c dng l phc tp thng xut hin min ni, trung du. Tn sut ln p dng cho cc cng trnh c dng l n nh thngxut hin vng ng bng.

1. Lu lng, mc nc ln nht trong tp hp thng k l lu lng, mc nc c tr sln nht xut hin trong tng nm. Cht lng ca chui thng k ( di, tnh i biu,thi gian thng k v.v...) cn phi tha mn cc yu cu nu trong cc tiu chun tngng. Cc s liu cn c x l v cng mt iu kin trc khi tin hnh tnh ton..

2. Nu pha thng ngun c nhng tc ng lm thay i iu kin hnh thnh dngchy hoc c cng trnh iu tit th khi xc nh cc yu t trong iu ny, cn phi kn kh nng iu chnh li dng chy ca cc cng trnh .

3. Nu pha h du c cng trnh iu tit, th m hnh x khng c ph hoi hocvt qu kh nng iu tit ca cng trnh .

4. Nhng cng trnh thu li cp I c Tiu chun thit k ring nu trong iu 2.12 tn sutl kim tra c th tnh vi p=0,01% hoc l cc hn khi kt qu tnh ton tin cy

c n nh c th trong "Tiu chun thit k".

4.2.2. Lu lng, mc nc thp nht tnh ton n nh kt cu cng trnh, nn mngc quy nh theo bng 4.3.

4.2.3. Mc nc ln nht tnh ton ch khai thc ca cc cng trnh cp nct chy t h, p dng bnh thng c xc nh theo bng 4.2, tr trng hp cnhng quy nh khng cho php khai thc cc mc nc ny phng nga ri ro cth gy ra cho h lu, hoc tri vi nhng quy nh v bo v iu. Trong trng hp, c quan thit k phi kin ngh mc nc khai thc an ton cp c thm quynquyt nh.

Bng 4.3. Lu lng, mc nc thp nht tnh ton n nh kt cucng trnh, nn mng

Loi cng trnh

Cp cng trnh

Tn sut lu lng, mc ncthp nht (%)

Thit k Kim tra

1. H cha I, II, III, IV v V Mc nc cht Mc nc tho cnthp nht sa

cha, no vt v.v...

2. Cng trnh trn sng I 99%

11


12/35

II 97% III 95% (khng qui nh)

IV 95% V 90%

3. H thng thot nc vcng trnh lin quan trongh thng ti tiu

I, II, III, IV v V Mc nc thpnht qui nhtrong khai thc

Mc nc tho cn sa cha, novt v.v...

Ch thch:

1. Lu lng, mc nc thp nht dng trong tp hp thng k l lu lng, mc ncc tr s b nht xut hin tng nm.

2. Khi cc h dng nc h lu yu cu phi bo m lu lng ti thiu ln hn lulng theo quy nh bng 4.3 th lu lng thp nht c chn theo lu lng tithiu . Mc nc thp nht tnh ton lc ny chnh l mc nc ng vi lu lng ti

thiu ni trn.3. Khi thit k cc cng trnh cp I, II cn phi xt n kh nng mc nc ny c thh thp hn do lng dn h lu b xi su hoc do nh hng iu tit li ca cc cngtrnh khc trong bc thang s c xy dng tip theo.

4.2.4. Mc nc ln nht sng nhn nc tiu tnh ton ch khai thc cho cccng trnh tiu nng nghip t chy hoc ng lc c xc nh theo bng 4.4.

4.2.5. Mc nc thp nht ngun (ti h cha hoc sng) tnh ton ch khai thc

cho cc cng trnh cp nc, tiu nc c quy nh theo bng 4.5.

Bng 4.4. Mc nc ln nht sng nhn nc tiu tnh ton ch

khai thc cho cc cng trnh tiu nng nghip

Cp cng trnh

Tn sut mc nc ln nht sng nhn nc tiu tnh ton ch khai thc

cho cc cng trnh tiu nng nghip (%)

Tiu t chy Tiu ng lc

I, II, III, IV v V

Mc nc ngoi sng ln nht c th tiut chy (1)

10% (2)

Ch thch:

(1) Mc nc ngoi sng ln nht c th tiu t chy xc nh c bng cch kim trakh nng thot nc ca u mi theo chui mc nc ngoi sng c nh gi l btli nht xy ra trong 10 nm lin tc. Lng ma tnh ton chnh l lng ma tngng xy ra cng thi gian, trong t nht c mt nm xy ra trn ma bnghoc ln hn trn ma tiu thit k.

Khi kim tra iu kin trn, nu 9/10 nm (ng vi mc bo m p=90%), hoc 8/10nm (ng vi mc bo m p=80%) hon ton tiu t chy c th quy m cng trnhla chn l ph hp vi mc bo m thit k.

Nu khng bo m c iu kin nu trn cn tip tc tng khu din tho hoc kthp gia tiu t chy vi cc bin php khc, hoc phi tiu hon ton bng ng lc tm ra phng n kh thi v kinh t - k thut nht.

12


13/35

(2) nhng tuyn chu p quan trng, cc sng v.v... tiu chun ny c th thay itu thuc vo cc quy nh an ton chng bo lt c th cho cc on sng ny.

Bng 4.5. Mc nc khai thc thp nht

Loicng trnh

Cpcng trnh

Tn sut mc nc khai thc thp nht (%)

Thit k Kim tra

T chy ng lc T chy ng lc1. H cha

I, II, III, IVv V

Mc nccht

2. Cng trnhtrn sng

I, II, III, IVv V

a) Ti nc,cp nc

Mc ncca sngcp ngunng vi tnsut nu

trong mcbo mthit k bng 4.1,phi ly lu lngthit k

Mc ncca sngcp ngunng vi tnsut nu

trong mcbo mthit k bng 4.1,phi ly lu lngthit k

Mc nc casng cpngun ng vitn sut nutrong mc

bo m thitk bng 4.1,cng thm5% vn mbo ly c75% lu lngthit k

Mc nc casng cpngun ng vitn sut nutrong mc bo

m thit k bng 4.1, cngthm 5% vnm bo lyc 75% lulng thit k

b) Tiu chonng nghip

I, II, III, IVv V

Mc ncti thiucn gitrong knhtiu theo

yu cusn xutnngnghiphoc mitrng

Mc nc b httng ngvi thigian tiu

m uv hoctiu u v

(Khng quinh)

(Khng quinh)

c) Pht in I, II, III, IVv V

Mc nckhai thcthp nht

(Khng quinh)

(Khng quinh)

(Khng quinh)

Ch thch:

1. Mc nc khai thc thp nht nu trong mc (a) l mc nc trung bnh ngy c tr s

thp nht xut hin trong thi on khai thc ca tng nm thng k.

2. Mc nc ti thiu khai thc nu trong mc (b) l mc nc thp nht cn gi cuithi on tiu nc m u v hoc tiu u v nhm tng hiu qu tiu do quy trnhkhai thc n nh.

4.2.6. Lu lng mc nc ln nht thit k cc cng trnh tm thi phc v cng tcdn dng quai, knh dn... c xc nh theo bng 4.6.Bng 4.6. Lu lng mc nc ln nht thit k cc cng trnh tm thi phc

v cng tc dn dng

Cp cng trnhTn sut lu lng, mc nc ln nht thit k cng

trnh tm thi phc v cng tc dn dng (%)

Trong 1 ma kh 2 ma khI 10% 5%

13


14/35

II 10% 5%

III 10% 10%

IV 10% 10%

V 10% 10%

Ch thch:

1. Lu lng, mc nc ln nht trong tp hp thng k l lu lng mc nc c tr sln nht xut hin trong tng ma dn dng. Ma dn dng l thi gian trong nm yucu cng trnh phc v cng tc dn dng cn phi tn ti chc chn, khi xut hin tnsut thit k. Tn sut thit k c ly theo bng 4.6

2. Nhng cng trnh phi thi cng nhiu nm, khi c lun chng chc chn nu thit kvi tn sut nu trong bng c th gy thit hi cho phn cng trnh chnh xy dngv tn tht v ngi, ti sn vt cht h lu ln hn ng k so vi phn u t thm chocng trnh dn dng th c quan thit k phi kin ngh tng thm mc bo m cho cngtrnh ny.

3. Nhng cng trnh b tng trng lc c iu kin nn tt cho php trn qua th c quanthit k c th kin ngh h mc bo m ca cng trnh tm thi gim vn xy dng.

Tt c kin ngh nng v h tn sut u phi c lun chng kinh t k thut chc chnv phi c c quan ph duyt chp nhn.

4.2.7. Lu lng ln nht thit k chn dng c xc nh theo bng 4.7Bng 4.7. Lu lng ln nht thit k chn dng

Cp cng trnh Tn sut lu lng ln nht thit k chn dng (%)

I 5%

II 5%

III 10%IV 10%

V 10%

Ch thch:

Lu lng trong tp hp thng k tnh ton l lu lng trung bnh ngy c tr s ln nhti vi dng chy khng b nh hng triu hoc lu lng trung bnh gi c tr s lnnht i vi dng chy chu nh hng ca triu xut hin trong thi on d tnh chndng ca tng nm thng k. Thi on d tnh chn dng c xc nh ty thuc voc im thy vn c th v khi lng cng tc nhng khng qu 30 ngy.

Cn c vo s liu o c thc t trong thi gian trc thi im n nh tin hnh chndng (thng tin hnh o c lin tc t thi im kt thc ma l n thi im nnh chn dng), c quan thi cng hiu chnh li phng n chn dng cho ph hp thct ca dng chy, thi tit, lch triu v trnh ln ch u t thng qua.4.2.8. Hnh thc, mt ct, cao trnh phn xy dng d dang (hoc phn t thi cng) cacc hng mc cng trnh thy lu di cn c quyt nh theo iu kin c th c xtn: Tin xy dng, iu kin kh tng thu vn, kh nng cung ng vt liu xydng nht l vt liu ti ch, mt bng thi cng, nng lc v tc xy dng ca n vthi cng, bin php x l khi gp l ln hn tn sut thi cng hn ch thit hi cngtrnh.

4.3. Cc ch tiu chnh v kh hu.

4.3.1. Tn sut ma tnh ton xc nh nhu cu nc cn cho h thng ti c quy

14


15/35

nh tnh vi p = 75%; khi c lun chng chc chn hiu qu kinh t do ti em li cth ngh nng tn sut ma tnh ton ln cao hn (xem ct ch thch bng 4.1).

Tn sut ma tnh ton xc nh nng lc tho dn cho h thng tiu nng nghip quynh p = 10 20% (xem ct ch thch bng 4.1).4.3.2. Khi khng c hoc khng s liu o dng chy tin cy xc nh lng nc

n cho cc h cha c php dng ti liu ma c tn sut tnh ton tng ng vimc bo m nu trong bng 4.1 suy ra lng nc n.

4.3.3. Ch tiu tnh ton cho cc yu t kh hu khc c qui nh c th trong cc tiuchun thit k chuyn ngnh tu thuc vo tng i tng v trng hp tnh ton.5. Ti trng, tc ng v t hp ca chng

5.1. Khi thit k cng trnh thy cn tnh n cc ti trng tc ng sau:

5.1.1. Cc ti trng thng xuynv tm thi (di hn v ngn hn):

a. Trng lng ca cng trnh v cc thit b c nh t trn v trong cng trnh.

b. p lc nc tc ng trc tip ln b mt cng trnh v nn; p lc nc thm (baogm lc thm v lc y ni th tch phn cng trnh v nn b bo ho nc; p lcngc ca nc ln mt khng thm ca cng trnh) ng vi mc nc ln nht khi xy ral thit k trong iu kin thit b lc v tiu nc lm vic bnh thng. Ring cc hngmc nm trong tuyn chu p ca h cha, p dng cn cn phi tnh thm cc p lcnu trong mc ny ng vi mc nc dng bnh thng.

c. Trng lng t v p lc bn ca n; p lc ca nham thch (gy ra cho cc hm l,tuynen).

d. Ti trng gy ra do kt cu chu ng sut trc.

e. p lc t pht sinh do bin dng nn v kt cu cng trnh, do ti trng bn ngoikhc.

g. p lc bn ct.

h. Tc dng ca co ngt v t bin.

i. Ti trng gy ra do p lc d ca k rng trong t bo ho nc khi cha c kt honton mc nc dng bnh thng, trong iu kin thit b lc v tiu nc lm vic bnhthng.

k. Tc ng nhit ln cng trnh v nn trong thi k thi cng v khai thc ca nm cbin dao ng nhit bnh qun thng ca khng kh l trung bnh.

l. Ti trng do tu, thuyn v vt tri (neo buc, va p).

m. Ti trng do cc thit b nng, bc d, vn chuyn v cc my mc, kt cu khc (cntrc, cu treo, palng v.v...), cht hng c xt n kh nng cht vt ti thit k.

n. p lc do sng c xc nh theo tc gi ln nht trung bnh nhiu nm.

o. Ti trng gi.

p. p lc nc va trong thi k khai thc bnh thng.

15


16/35

q. Ti trng ng sinh ra trong ng dn c p v khng p khi dn mc nc dngbnh thng.

5.1.2.Cc ti trng tm thi c bitgm:

a. Ti trng do ng t hoc n.

b. p lc nc tng ng vi mc nc khi xy ra l kim tra.c. Ti trng gy ra do p lc d ca k rng trong t bo ho nc khi cha c kt honton ng vi mc nc kim tra ln nht trong iu kin thit b lc v tiu nc lm vicbnh thng hoc mc nc dng bnh thng nhng thit b lc v tiu nc b hng.

d. p lc nc thm gia tng khi thit b chng thm v tiu nc khng lm vic bnhthng.

e. Tc ng do nhit trong thi k thi cng v khai thc ca nm c bin dao ngnhit bnh qun thng ca khng kh l ln nht.

g. p lc sng khi xy ra tc gi ln nht thit k.

h. p lc nc va khi t ngt ct ton b ph ti.

i. Ti trng ng sinh ra trong ng dn c p v khng p khi dn mc nc ln nhtthit k.

k. p lc pht sinh trong mi t do mc nc sng, h b h thp t ngt (rt nhanh).

5.2. Khi thit k cng trnh thy phi tnh ton theo t hpti trng c bn vkim tratheo t hp ti trng c bit:

a. T hp ti trng c bn bao gm cc ti trng v tc ng: thng xuyn, tm thi dihn, tm thi ngn hn m i tng ang thit k c th phi tip nhn cng mt lc.

b. T hp ti trng c bitvn bao gm cc ti trng v tc ng xt trong t hp titrng c bn nhng mt trong chng c thay th bng ti trng (hoc tc ng) tmthi c bit. Trng hp ti trng c bn c xt thm ti trng ng t hoc n cngc xp vo loi t hp c bit. Khi c lun chng chc chn c th ly 2 trong cc titrng hoc tc ng tm thi c bit kim tra. Thit k phi la chn a ra thp ti trng c bn v t hp ti trng c bitbt li nhtc th xy ra trong thi kthi cng v khai thc cng trnh.

6. Cc quy nh tnh ton ch yu6.1. Khi tnh ton n nh, bn, ng sut, bin dng chung v cc b cho cc cngtrnh thy v nn ca chng, phi tin hnh theo phng php trng thi gii hn. Cctnh ton cn phi tin hnh theo hai nhm trng thi gii hn:

a. Trng thi gii hn th nht- Cng trnh, kt cu v nn ca chng lm vic trong iukin khai thc bt li nht, gm: cc tnh ton v bn v n nh chung ca hcng trnh- nn; bn thm chung ca nn v ca cng trnh t; bn ca cc bphn m s h hng ca chng s lm cho vic khai thc cng trnh b ngng tr; Cctnh ton v ng sut, chuyn v ca kt cu b phn m bn hoc n nh cng

trnh chung ph thuc vo chng v.v...b. Trng thi gii hn th hai - Cng trnh, kt cu v nn ca chng lm vic bt li trongiu kin khai thc bnh thng, gm: cc tnh ton bn cc b ca nn; Cc tnh ton

16


17/35

v hn ch chuyn v v bin dng, v s to thnh hoc m rng vt nt v mi ni thicng; V s ph hoi bn thm cc b hoc bn ca kt cu b phn m chngcha c xem xt trng thi gii hn th nht.

6.2. m bo kt cu v nn ca cng trnh thy trong tnh ton cn phi tun thiu kin sau:

mnc . Ntt R

kn

R nc.knhoc K=

Ntt m

Trong :

nc - H s t hp ti trng.

- Trong tnh ton theo trng thi gii hn th nht:

nc = 1,00 - i vi t hp ti trng c bn;= 0,90 - i vi t hp ti trng c bit;= 0,95 - i vi t hp ti trng trong thi k thi cng v

sa cha.

- Trong tnh ton theo trng thi gii hn th hai: nc = 1,00

K - H s an ton chung ca cng trnh; Bnh thng h s K khng c vt qu 15%gi tr nc.kn /m tr trng hp c nhng quy nh ring.

Ntt - Ti trng tnh ton tng qut (lc, mmen, ng sut), bin dng hoc thng s khcm n l cn c nh gi trng thi gii hn.

R - Sc chu ti tnh ton tng qut, bin dng hoc thng s khc c xc lp theo tiuchun thit k (TCVN, TCXD, TCXDVN, TCN).

m - H s iu kin lm vic: xt ti hnh loi cng trnh, kt cu hoc nn, dng vt liu,tnh gn ng ca s tnh, nhm trng thi gii hn v cc yu t khc c qui nhtrong cc ti liu tiu chun thit k hin hnh cho mi loi cng trnh, kt cu v nnkhc nhau. H s iu kin ca mt s cng trnh thy in hnh qui nh ph lc B.

kn - H s bo m c xt theo quy m, nhim v ca cng trnh.

- Khi tnh ton trng thi gii hn theo nhm th nht: kn c xc nh theo cp

cng trnh:

Cng trnh cp I ly kn= 1,25Cng trnh cp II ly kn= 1,20Cng trnh cp III, IV v V ly kn= 1,15

- Khi tnh ton theo trng thi gii hn th hai: ly kn = 1,00.

- Khi tnh ton n nh cho nhng mi dc t nhin nm k st cng trnh khc c

h s bo m ln hn: phi ly h s bo m ca mi bng h s bo m ca cngtrnh .

6.3. Tr s ca cc h s sai lch v vt liu nvl v t n dng xc nh sc khngtnh ton ca vt liu v cc c trng ca t c nu trong tiu chun thit k quinh ring bit cho mi loi cng trnh thy, kt cu v nn ca chng.

17


18/35

Khi cng trnh s dng khi lng ln vt liu ti ch bao gm c vt liu t p, pv.v... sc khng tnh ton ca vt liu c xc nh thng qua x l thng k cc kt quth nghim trong phng v nghin cu thc nghim ti hin trng.

6.4. Tnh ton theo trng thi gii hn th nht c thc hin vi ti trng tnh ton. Titrng tnh ton bng ti trng tiu chun nhn vi h s lch ti n (bng 6.1). Ti trng

tiu chun c nu trong tiu chun kho st thit k qui nh ring bit cho mi loicng trnh, kt cu v nn ca chng.

Bng 6.1. H s lch ti (n)Tn cc ti trng v tc ng H s lch ti (n)

- Trng lng bn thn cng trnh (khng k trng lng t, lp ong hm)

1,05 (0,95)

- Trng lng bn thn ca lp o ng hm 1,20 (0,80)- p lc thng do trng lng t gy ra 1,10 (0,90)- p lc bn ca t 1,20 (0,80)- p lc bn ct 1,20

- p lc :+ Trng lng ca khi to vm 1,50+ p lc ngang ca 1,20 (0,80)

- Trng lng ton b lp t, trn ng hm hoc trng lngvng b ph hu v.v... (p lc thng ng do trng lng t gy ra)

1,10 (0,90)

- p lc nc trc tip ln b mt cng trnh v nn, p lc sng, plc nc y ngc cng nh p lc nc thm, p lc k rng

1,00

- p lc tnh ca nc ngm ln lp o ng hm 1,10 (0,90)- p lc nc bn trong ng hm (k c nc va) 1,00- p lc mch ng ca nc 1,20- p lc ca va khi pht xi mng 1,20 (1,00)- Ti thng ng v nm ngang ca my nng, bc d, vn chuyncng nh ti trng ca cc thit b cng ngh c nh

1,20

- Ti trng xp kho trong phm vi bn xp d, hot ng ca culn

1,30

- Ti trng do gi 1,30- Ti trng do tu thuyn 1,20- Tc ng ca nhit v m 1,10- Tc ng ca ng t 1,10- Ti trng bc hng khi 1,30 (1,00)

Ch thch:

1. H s lch ti do tu chy trn ng st, xe chy trn ng t, phi ly theo tiuchun thit k cu;

2. Cho php ly h s lch ti bng 1,00 i vi trng lng ca bn thn cng trnh, p

lc thng ng do trng lng ca khi t p, nu trng lng ca khi c xcnh t cc gi tr tnh ton c trng ca t (trng lng ring v c trng bn), cnb tng c xc nh t c trng vt liu (trng lng ring ca b tng v cc ctrng khc) ph hp vi cc tiu chun th nghim, v tiu chun thit k nn hin hnh;

3. Ch s dng cc h s lch ti ghi trong ngoc n khi kt qu tnh ton th hin cngtrnh trong tnh trng bt li hn.

6.5. Tnh ton theo trng thi gii hn th hai cho cng trnh, kt cu v nn c thchin vi h s lch ti (n), h s sai lch v vt liu nvl v t n u ly bng 1,00 trcc trng hp c qui nh c th trong tiu chun kho st thit k chuyn ngnh.

6.6. Cc ni dung cn thit phi tnh ton, cc gi nh trng hp tnh ton, s tnhcho cng trnh v nn phi ph hp vi kh nng c th xy ra, tun th y cc tiu

18


19/35

chun kho st thit k hin hnh v cui cng phi tm c li gii bt li nht. Trongnhng trng hp cn thit cn phi xt thm cc yu t sau:

a. Trnh t thi cng v trnh t cht ti ca cc b phn cng trnh.

b. nh hng ca cc tc ng ca nhit , co ngt v tc ng ca p lc thm tbin.

c. Cc bin dng phi tuyn n hi v do cng nh tnh t bin ca vt liu cu thnhcng trnh v nham thch nn.

d. Tnh ri rc ca cu trc thn cng trnh v nn ca chng ( nt n v.v...).

e. Tnh khng ng nht ca vt liu xy dng, nham thch nn v tnh d hng cachng.

6.7. Khi tnh ton cc kt cu cng trnh trn nn b ln phi xt ti ni lc pht sinhtrong chng do bin dng ca nn gy ra. ln v chnh lch ln phi nm trong giihn cho php, khng gy bt li cho khai thc v bn, bin dng ca cng trnh, kt

cu tng b phn hoc gia cc b phn vi nhau.6.8. Nhng cng trnh dn, tho, x nc cp I, II phi tin hnh th nghim m hnh thylc xc nh kh nng dn tho nc, kim tra ch thy lc, vn tc, p lc ncln cng trnh, gii php ni tip cng trnh vi thng h lu, bin php gia c chng mimn, xm thc v.v... xc nh hnh dng kch thc cc b phn, la chn phng n btr tng th cm u mi mt cch hp l v kinh t nht. iu ny cng c php pdng cho cc cng trnh cp III c hnh dng ng dn phc tp m nhng ch dn tnhton thy lc thng thng khng t c tin cy cn thit, ng thi trong thc tcha c hnh mu xy dng tng t khi c lun chng tho ng.

6.9. Tng t, khi cha c cc ch dn v phng php tnh ton tin cy xc nhtrng thi lm vic v n nh ca cc kt cu phc tp, tnh trng thm trong nn vcng trnh, nh gi kh nng lin kt gia nn v cng trnh, xc nh mt s ch tiuc trng ca a khi v.v... cho cc cng trnh cp I v II phi tin hnh cc nghin cuthc nghim tng ng.7. Nhng yu cu ch yu i vi cc cng trnh thu

7.1. p

7.1.1. Kiu v kt cu p cn la chn trn c s so snh kinh t - k thut cc phngn, tu thuc vo nhim v, thng s ca cng trnh, iu kin t nhin ti ch (thy vn

v kh hu, a hnh, a cht cng trnh, kin to khu vc v ng t, vt liu xy dngti ch v.v...), b tr tng th ca cm u mi, s t chc thi cng, thi hn thi cng,iu kin khai thc p, ngun nhn lc vt liu v trang thit b thi cng.

7.1.2. Khuyn khch p dng cc hnh loi, cng ngh xy dng p mi nhm khc phcnhng nhc im ca cc loi p truyn thng nh khi lng xy dng ln, thi gianthi cng ko di, tc thi cng b hn ch trong ma ma, nhit trong khi xy crt cao v.v...

7.2. Cng trnh ly nc

7.2.1.Cng trnh ly nc phi m bo:

a. Cp nc lin tc cho ng dn theo yu cu;

19


20/35

b. C kh nng iu chnh v ch ng ngng cp nc vo ng dn khi cn tin hnhkim tra, sa cha theo quy trnh vn hnh hoc trng hp gp s c;

c. Phi b tr li chn rc, thit b hoc phng tin thu gom rc, bc phn vo, blng ct, hnh lang tho ra v.v... ngn nga v loi b bn ct, vt ni, c rc xmnhp vo ng dn.

7.2.2. Kiu kt cu v b tr tng th ca cng trnh ly nc cn phi la chn ph hpvi nhim v ca cng trnh v ty thuc vo kiu ng dn (c p - khng p - hn hp;iu tit v khng t iu tit); c im ca cng trnh thu nc (kiu c p - kiukhng p); iu kin t nhin: ch thy vn, dng chy bn ct, hnh thi b, s hindin ca c rc, vt ni, ch vn hnh v bi lng thng lu cng trnh.

Cn m bo nc vo ng dn c p khng ht theo khng kh v c tn tht ctnc t nht.

Thng thng ca ly nc c thit k gm mt s n nguyn khi cn thit c thtch ri tng n nguyn tin hnh sa cha hoc no vt.

7.2.3. Khi b tr cng trnh ly nc sinh hot t h cha phi xt n kh nng ti tong b, cht lng nc hin ti v trong tng lai trn cc on quyt nh v trt cng trnh; ng thi phi xem xt mc hm kh v s chy dn xit cng nhhm lng sinh khi dng mt bao gm c ru rong, to v tr ny.

7.2.4. Vic chn kiu cng trnh ly nc phi tu thuc vo cc loi mc nc in hnhtrn sng v cao trnh mc nc yu cu t trong ng dn chnh, c xt n iukin thy vn, a hnh v a cht ti ch.

Cng trnh ly nc khng p c s dng trong trng hp mc nc sng lun m

bo cao hn cao trnh mc nc yu cu ca ng dn chnh. Trong trng hp mcnc sng ti tuyn cng trnh ly nc thp hn mc nc yu cu ca ng dn chnhth phi dng cng trnh ly nc c p.

Cho php thay th cng trnh ly nc c p bng trm bm thng qua so snh hiu quu t.

7.2.5. Mc nc tnh ton thng lu cng trnh ly nc qui nh nh sau:

a. Vi cng trnh ly nc khng p - Mc nc tng ng vi lu lng tnh ton lnnht thit k v kim tra ti tuyn cng trnh c xc nh ph hp vi cc yu cu iu

4.2.1 ca Tiu chun ny.b. Vi cng trnh ly nc c p - Mc nc tng ng thng lu p khi x lu lngtnh ton ln nht thit k v kim tra.

7.2.6. bo m iu kin vn hnh khai thc v phng nga s c cho bn thn cngtrnh, cho ng dn - trang thit b cng ngh ca cc cng trnh pha sau cn trang bcc loi ca van thch hp cho ca nhn nc. Loi ca van, s lng, v tr c xc nhtheo nhim v c th ca cng trnh.

7.2.7. m bo nc a vo ng dn c trong cn thit phi d kin cng trnh

lng ct cng cc thit b thch hp v c quyt nh trn c s tnh ton kinh t - kthut.

20


21/35

7.2.8. Khi thit k cng trnh ly nc phi tun th cc yu cu nu iu 4.11 phn 4 -Cc cng trnh cho c i v cng trnh bo v c.

7.3. B lng ct

7.3.1. B lng ct v thit b cn phi bo m:

a. Gi li trong b cc ht bn ct c ln vt qu tr s cho php ly c nc c trong ph hp vi yu cu cht lng. ln ca bn ct cho php a vo ngdn c xc nh thng qua tnh ton kinh t - k thut (tn dng lng ph sa c ch mc ti a; Hn ch hoc khng gy bi lng hoc xi l knh dn; Khng lm gim tuith trang thit b cng ngh di mc qui nh v.v...);

b. m bo cp nc c trong ph hp p ng biu dng nc;

c. Ch ng loi b bn ct lng ng trong bung lng khi cn thit. Tn dng bin phpxi ra bn ct lng ng bng phng php thy lc.

7.3.2. Tnh ton b lng ct trn knh ca h thng ti phi cn c vo thnh phn bn

ct ca nm c c trung bnh v kim tra kh nng lm vic ca b theo nm c c ln nht c xt n ch lm vic ca knh.

7.3.3. V tr b lng ct cn t trong phm vi cm u mi hoc u ng dn chnhc xt n cc iu kin sau:

a. iu kin a hnh v a cht ti ch cho php b tr ng dn nc ti b lng ct ckch thc v ch chy thch hp nhng ht bn ct c hi lng ng trong bunglng;

b. C kh nng x b bn ct lng ng ra khi bung lng hoc dn ng trong b

no vt nh k bng c gii.

7.3.4. Vic chn kiu bung lng thau ra lin tc hoc nh k bng phng php thylc hay lm sch bng c gii phi tin hnh trn c s so snh kinh t - k thut, lachn kiu bung lng da trn c s sau:

a. Bung lng thau ra bng thy lc p dng cho nhng ni c lng nc tha phongph, tuyn thau ra c dc thy lc;

b. Khi khng chnh ct nc xi ra ton b lp lng ng trong b cn s dngbung lng thau ra kiu hn hp: bn ct ht nh c loi b bng phng php thy

lc, bn ct ht ln c dn sch bng c gii;c. Cc b lng ct kiu mt bung thau ra nh k ch p dng khi c php ngng cpnc hon ton hoc c php cp nc cha x l (th) trong thi gian thau ra.

7.3.5. Khi thit k cng trnh thu nc v ly nc cho h thng cp nc sinh hot vnc cho cc ngnh sn xut khc phi tun th yu cu ca cc tiu chun thit kmng li bn ngoi v cng trnh cp nc tng ng.

7.4. Cng trnh x nc, tho nc

7.4.1. Cng trnh x nc, tho nc phi m bo thc hin cc chc nng sau y:

a. i vi cng trnh x:

21


22/35

- Cc cng trnh x lu di bao gm cc ca trn, l x, ng dn tucbin v.v... c mttrong u mi thy lc v cng trnh x l d phng phi nng lc m bo cho mcnc thng h lu khng vt qu mc nc qui nh khi x l thit k v l kim tra.

Thng thng cc cng trnh x l d phng ch lm vic khi mc nc thng lu btu vt qa mc nc thit k ln nht. Khi khng c iu kin b tr cng trnh x l d

phng ring bit th phi m rng cng trnh x chnh hoc nng p tng dung tchiu tit ca h cha, hoc kt hp c hai m bo x l kim tra an ton.

- Ch ng x nc theo quy trnh qun l khai thc.

b. i vi cng trnh tho:

- Tho cn hon ton hoc mt phn h cha hoc ng dn (knh) xem xt v sacha cng trnh cng nh dn sch theo yu cu v sinh mi trng hoc rt ncphng s c cho cng trnh chu p;

- Xi ra bn ct;

- C th tham gia tho l.

7.4.2. Khi thit k cng trnh x nc, tho nc cn xem xt kh nng kt hp chngvi cc cng trnh khc trong cm u mi cng nh tnh n kh nng s dng chng x lu lng thi cng.

7.4.3. Lu lng x tnh ton trong qu trnh khai thc qua cc cng trnh x - tho -chuyn nc lu di ca cng trnh u mi cn xc nh xut pht t lu lng l thitk c qui nh khon 4.2.1 iu 4.2 v bng 4.2 c xt n s bin i ca n do tcng iu tit li ca cc h cha hin c hoc h cha ang thit k v s thay i iu

kin hnh thnh dng chy do nhng hot ng kinh t x hi trong lu vc.Khi xc nh lu lng ln nht thit k v kim tra ca cng trnh u mi trn sng khaithc theo s bc thang cn xt n cp ca bn thn cng trnh, v tr ca n trongbc thang, nng lc x -tho - chuyn nc ca cm u mi bc trn ng vi mcnc dng bnh thng v mc nc gia cng (khi x l thit k v l kim tra), quy nhvn hnh khai thc cng trnh thu v h cha ca cc bc thang, dng chy nhp luca cc sng nhnh vo on sng thng lu tip cn vi cng trnh u mi ang thitk.

Khng ph thuc vo cp ca cng trnh u mi v v tr ca chng trong bc thang, qu

trnh x - tho - chuyn lu lng v h lu ca trng hp tnh ton c bn khng cnh hng n vic khai thc bnh thng ca cc cng trnh thu lu di bc thangdi.

Trng hp cp ch yu ca cng trnh u mi ang thit k thp hn cp ca cngtrnh u mi bc trn, cho php tng nng lc x - tho - chuyn dn c lulng kim tra ca cng trnh u mi bc trn m khng nng cp thit k cng trnh.

a. Mc nc thit k ln nht thng lu cng trnh u mi: l mc nc cao nht xuthin trong qu trnh x l thit k khi cc cng trnh x nc m hon ton, tt c cc

tuc bin u lm vic, cc cng trnh tho, chuyn nc khc lm vic ch khai thcbnh thng.

22


23/35

Khi khai thc trng hp ny cc hng mc trong cng trnh u mi k c phn nitip thng h lu cng trang thit b phi bo m lm vic bnh thng, khng b hnghc.

Ti trng v tc ng ng vi trng hp ny c tnh theo t hp ti trng c bn.

b. Mc nc kim tra thng lu cng trnh u mi: l mc nc cao nht xut hin

trong qu trnh x l kim tra khi tt c cc cng trnh tho nc, x nc, chuyn ncv.v... ni mc (a) v cng trnh x d phng u hot ng.

Khi khai thc trng hp ny cho php:

- Gim sn lng ca trm thy in (nu iu c li cho an ton cng trnh).

- Cng trnh ly nc lm vic khc iu kin khai thc bnh thng nhng khng dn ntnh hung s c cho cc i tng dng nc.

- Tho nc qua ng dn kn vi ch thy lc thay i (t khng p sang c p vngc li) nhng khng dn n ph hng ng dn.

- Lng dn v mi dc h lu cng trnh u mi b xi l nhng s h hng ny khnge da ph hy cc hng mc chnh ca cng trnh u mi, cc vng dn c, cngnghip h lu.

- C h hng cng trnh x d phng nhng s h hng ny khng nh hng n anton ca cng trnh chnh.

- Ti trng v tc ng ng vi trng hp ny c tnh theo t hp ti trng c bit.

7.4.4. thun li cho vic chun ho v tng kh nng lp ln khi cn thit, b rngca l thot ch nht c ca van nn ly theo cc kch thc sau: 0,40; 0,60; 0,80; 1;

1,25; 1,50; 1,75; 2; 2,50; 3; 3,50; 4; 4,50; 5; 6; 7; 8; 10; 12; 14; 16; 18; 20; 22; 24; 30m.Tng t, chiu cao ca l thot l 0,6; 0,8; 1; 1,25;1,5; 1,75; 2; 2,5; 3; 3,5; 4; 4,5; 5; 5,5;6; 7; 8; 9; 10; 12; 15; 16; 18; 20m.

Ch thch:Chiu rng ca l l kch thc trong lng nh nht gia hai mt bn thng

ng.Chiu cao ca l c xc nh nh sau:- Vi cc l mt- l kch thc t mt ngng n mc nc dng bnh thng.- Vi cc l di su - l kch thc t mt ngng n trn ca l.

7.4.5. Vic quyt nh t lu ca cng trnh, vn tc lng dn h lu, ch ni tip

thng h lu, kt cu cng trnh chnh, b tiu nng, sn sau, gia c b, tng chuyntip v phn cch ca cng trnh x nc, tho nc phi cn c vo kt qu so snh chtiu kinh t - k thut cc phng n.

B tr tng th v kt cu ca cng trnh x nc, tho nc, gii php ni tip cng trnhvi h lu phi bo m khi chng hot ng s khng gy nguy him cho cc hng mccng trnh thy trong cng trnh u mi do xi nn. Dng nc x, tho khng c nhhng n hot ng bnh thng ca nh my thu in, knh giao thng thy, khnggy ra nhng bin dng lng dn bt li cho khai thc.

Bn thn cng trnh x nc, tho nc khi thit k cn phi xt n nhng tc ng btli do lc thy ng, kh thc v hin tng mi mn do bn ct gy ra.

23


24/35

7.4.6. Kt cu ca cng trnh x nc, tho nc v cc b phn ni tip thng h luca chng c thit k vi cc trng hp khai thc c bn v phi kim tra li vitrng hp bt thng m bo an ton cho cng trnh v khng c php nc trn qua nh tuyn chu p, gm:

a. Cng trnh x nc, tho nc lm vic khi gp l thit k c m hon ton. Khi c

lun chng tho ng cho php xt n kh nng mt s ca b kt;b. Cng trnh x nc, tho nc lm vic khi gp l kim tra c m hon ton. Khngxt n kh nng ca b kt;

c. Do yu cu vn hnh khai thc, iu tit l hoc s c c th phi xt thm cc t hpm khc p ng mc tiu thit k v an ton cho cng trnh.

7.4.7. Khi thit k cng trnh x nc, tho nc cn phi lp quy trnh vn hnh cc ca.V nguyn tc th quy trnh ny khng c gy ra xi l ngoi d tnh thit k dn nphi b sung nhng bin php phng xi h lu.

7.4.8. Khi thit k cng trnh x nc, tho nc phi trang b ca van chnh v ca vansa cha.

Trc ca van chnh ca cng trnh x mt l van phng cng nh trc ca van chnhca cng trnh x su (khng ph thuc vo dng ca van chnh) cn phi b tr ca sacha - s c. Nhng cng trnh x mt c nhiu khoang cng loi cho php s dng cavan phng s c - sa cha loi di chuyn c gim bt s lng. Khi c lun chngtin cy cho php dng phai tm ln thay cho van phng s c.

Khi khng c kh nng tho cn l phn vo ca cng trnh x su th ngoi ca vanchnh v van sa cha - s c cn phi b tr thm ca van sa cha (c th l phai sacha) pha trc.

Khi ngng cng trnh x su thp hn mc nc h lu th phn sau mt ct ra cacng phi b tr thm ca van sa cha loi di chuyn c.

7.4.9. Khi la chn kiu ca van v my nng phi cn c vo tc ln ca l, khnng tch nc thng h lu, yu cu bo m lu lng ti thiu cho h lu, trong bao gm c trng hp ct t ngt mt phn hoc ton b ph ti ca nh my thyin quyt nh.

7.4.10. Khi ca van ca cng trnh x su l ca phng c din tch trn 60m2 song li cyu cu tho lu lng nh hn ng k so vi kh nng tho ca 1 l cng th phi thitk 1 l tho ring nh hn tha mn yu cu ny.

7.5. ng dn nc kn ca nh my thu in v trm bm

7.5.1. ng dn kn (c mt ct ngang khp kn) ca nh my thy in, trm bmphi m bo dn nc vi mi ch khai thc d kin trong thit k.

7.5.2. Vic la chn tuyn v mt ct dc ng dn nc c p v nguyn tc cn philoi tr kh nng sinh chn khng trong ng dn khi lm vic.

24


25/35


26/35

7.6.6. Vi ng ng dn bng b tng ct thp cn phi nh r tiu chun hn ch ntnhm m bo tui th ca kt cu theo cc iu kin n mn v chng thm.

7.7. Tuynen thy cng

7.7.1. La chn tuyn, kiu (c p hoc khng p) cng nh kt cu v hnh dng mtct ngang ca tuynen cn phi cn c vo nhim v ca chng v tin hnh trn c s so

snh kinh t - k thut cc phng n, c xt n: b tr tng th cm u mi; chiu sut di mt t; tr s ct nc; iu kin a cht cng trnh; ch thy lc catuynen; iu kin thi cng; nh hng qua li gia tuynen vi cc cng trnh b tr trnmt t v cng trnh ngm lin k.

7.7.2. V nguyn tc, tuyn tuynen thit k cn la chn l tuyn thng vi chiu dingn nht. Trong iu kin a cht cng trnh v a cht thy vn khng thun, thi cngphc tp hoc cn p ng theo yu cu an ton cho php p dng tuyn tuynen khngthng.

7.7.3. Khi tuynen c nhim v tho lu lng khai thc lu di cn phi tnh n khnng s dng chng tho lu lng thi cng.7.8. H iu tit ngy m, b p lc ca nh my thy in, trm bm, thpiu p

7.8.1. Khi dung tch iu tit thng lu ca nh my thy in knh dn khng phi xt n vic to h iu tit ngy m. S thiu ht dung tch iu tit phi chngminh bng cc tnh ton kinh t - k thut.

7.8.2. H iu tit ngy m phi b tr trn tuyn knh dn hoc trn nhnh ca n, cng gn b p lc cng tt. Ty thuc iu kin ti ch c th s dng cc lng sng,vng trng t nhin lm h iu tit ngy m nhng phi xt n iu kin thm mtnc v kh nng b bi lp ca h.

7.8.3. Khi thit k h iu tit ngy m cho nh my thy in lm vic theo ch ph nh phi c bit quan tm n n nh, bn ca cc cng trnh ngn nc bngt v lp o bo v khi mc nc trong h b giao ng ln.

7.8.4. Khi thit k b p lc cn c gii php m bo:

a. Nc i vo ng dn tucbin khng ht theo khng kh v c tn tht ct nc l

nh nht;b. Ngn nga vt ni v rc tri vo ng dn tucbin;

c. Ch ng ngng cp nc vo ng dn tucbin khi cn xem xt, sa cha hoc sc;

d. B tr thit b thch hp np khng kh vo ng dn tucbin khi tho cn vdn khng kh trong ng dn ra ngoi khi chng c lm y nc;

e. X nc tha cng nh vt tri ni v rc ri;

g. Loi b bn ct lng ng trong b.

Cn trang b ca van, phai sa cha, li chn rc, thit b dn rc cho b.

26


27/35

7.8.5. Khi xc nh cao trnh nh tng b p lc cn phi xt n tc ng ca sngdng pht sinh do ct t ngt ton b ph ti.

7.8.6. Khi xc nh mc nc khai thc thp nht trong b p lc cn phi xt n tcng ca sng m pht sinh do ng ph ti ln nht.

7.8.7. Khi b p lc c cp nc bng ng dn khng t iu chnh, cn b tr cngtrnh x t ng nm k b p lc. Cc cng trnh x ny phi m bo thot c tonb lu lng tnh ton ln nht ca nh my thy in hoc lu lng cn cp cho cc hdng nc h lu khi nh my thy in ngng lm vic c xt n cc ngun d trln cn.

7.8.8. Khi b p lc c cp nc bng ng dn t iu chnh, trong trng hp cnthit cn b tr cng trnh x k b p lc cp nc cho nhng h pha h lu trongtrng hp nh my thy in ngng lm vic.

7.8.9. Khi b tr b p lc trn nn t, c bit l trn t yu, cn d kin bin php phng ln khng u, hin tng trt c th xut hin do nc thm ra t b p lclm suy gim cht lng nn.

Khi thit k b x ca trm bm cn phi d kin cc bin php nhm bo m:

a. Tiu hao ng nng ca nc chy ra t ng y;

b. Loi b bn ct lng ng trong b x;

c. Ni tip thun b x vi knh hoc vi ng dn.

7.8.10. Ni tip ng y vi b x ca trm bm c th thc hin theo cc hnh thc sau:

a. ng y bm nc trc tip vo b x. Ming ra ca ng y lun thp hn mc ncthp nht trong b mt khong cch an ton. Cui mi ng y c t mt van clap ngn dng chy ngc khi dng bm. Trng hp c bit khi khng c php h thpmc nc trong b x xung thp hn cao trnh y ca van clap th phi trang b thmmt van trn ng y ngn dng chy ngc khi tin hnh sa cha cc van clap;

b. Khi dng hnh thc xiphng ngc chuyn nc t ng y vo b x th ming raca xi phng phi nm thp hn mc nc thp nht trong b x. Xiphng c trang bvan np kh t ng ph chn khng pht sinh trong xi phng khi dng bm, ngnnga dng chy ngc t b x v my bm.

Vic la chn phng n ni tip cn phi thng qua so snh kinh t - k thut.

7.8.11. S cn thit phi b tr thp iu p bo m cho cc t my pht lmvic an ton cn phi chng minh bng s liu tnh ton nc va.

7.8.12. Tnh ton thy lc ch chuyn i trong thp iu p phi tin hnh ch ngt v ng ph ti. Mc nc dng cao nht trong thp iu p c xc nh theoiu kin ct t ngt ton b ph ti. Khi mc nc thng lu phi ly mc ncln nht, cn tn tht ct nc l tn tht b nht c th xy ra.

Mc nc thp nht trong thp iu p c xc nh theo iu kin tng t ngt phti ti a khi khai thc. Khi mc nc thng lu phi ly bng mc nc thp nht,cn tn tht ct nc ly theo tn tht ln nht c th xy ra.

27


28/35

7.9.Knh dn nc

7.9.1. Vic la chn tuyn, dng knh, cc thng s, tn tht u nc phi c lunchng bng cch so snh phng n c xt n: kh nng chuyn nc, kh nng png giao thng thy (nu c), khi lng cng tc xy dng v trang thit b, phngthc vn hnh iu phi nc, chi ph khai thc, yu cu bo v mi trng xung quanh

v.v...

7.9.2. Nu khng c yu cu khng ch cao mt nc th knh cn b tr trong khio hoc na o na p. Ch cho php s dng knh p nhng on c bit khi clun chng ring. Khi xc nh bn knh cong ca tuyn knh cn m bo kh nng i lica thuyn b v khng gy ra xi l lng dn.

7.9.3. Cn d kin bin php chng ngp v snh ly ha vng t ven tuyn knh cngnh thc vt thy sinh pht trin trong knh.

7.9.4. Khi thit k knh trong nhng iu kin phc tp (trong t ln t, trng n, tcha mui d ha tan, trn sn dc trt l, nhng ni tuyn knh c th giao ct vidng bn v.v...) cn xt n s thay i c trng ca t nn v t p trong thigian khai thc sau ny v trong trng hp cn thit phi p dng cc gii php kt cuv cng ngh thi cng thch hp.

7.9.5. Lu tc trong knh c quyt nh theo iu kin khng gy xi hoc bi tronglng dn. Ngoi ra, cn d kin bin php phng nga tc nghn lng dn do rc ri,rong to, cy c ph mt.

7.9.6. knh khng b xi l v h hi c hc do ma, do dng chy, do thm mt nccn d kin kt cu bo v thch hp.

7.9.7. dc mi knh phi xc nh t iu kin n nh mi dc.

7.9.8. m bo t tiu chun trong ca nc dng, cn phi d kin cng trnhlng ct hoc thay th bng gii php m rng kch thc on u knh. Hnh thc lngct s c quyt nh thng qua lun chng kinh t - k thut.

7.9.9. Khi thit k knh cn tnh n kh nng phn on thun li cho vic kim trabo dng nh k. Chiu di mi on c quyt nh theo iu kin c th c tnh n

iu kin t nhin v cc yu cu khai thc sa cha.

7.9.10. Khi thit k knh cn xem xt kh nng s dng ngun nc b sung t sngsui giao ct. Lng dng chy b sung l lng nc c bn ca sng sui sau khi trphn lu lng phi cp v h lu cho nhu cu v sinh mi trng.

7.9.11. Thng thng, dc knh cn b tr ng qun l kim tra thng xuyn tnhtrng ca knh. Nhng ni knh i qua cc khu vc nguy him, t im dn c, cc cngtrnh dn dng c th phi xt n vic xy dng hng ro cch ly.

7.9.12. Khi s dng ngun b sung t cc sng sui cn phi tun th cc iu kin sau:

a. Cc ch tiu cht lng nc tuyn ly nc phi ph hp vi yu cu ca tiu chunnc dng;

28


29/35

b. Lng dng chy rn v thnh phn ht ca n phi ph hp vi kh nng chuyn tica knh.

7.9.13. Tnh ton thu lc knh cn phi xt n ch chy khng n nh xut hinkhi lu lng v mc nc thay i, nh hng ca nc dnh do gi, sng do gi vsng to thnh khi vn hnh ca van, vn hnh t my, cng trnh iu tit, trm bm,

u thuyn v.v...

7.9.14. Trn cc on tuyn knh c iu kin a hnh, a cht khng thun li (ahnh b chia ct cc b, gp cc loi t d b xi, t yu v.v...) cn phi xem xt phngn thay th bng cu mng.

7.9.15. Thit k knh a chc nng phi tin hnh trn c s d bo nhu cu nc vyu cu cht lng thch ng cho cc h dng nc trong vng D n m knh c nhimv cung cp.

7.9.16. Khi thit k knh kt hp vn ti thy phi cn c vo loi tu thuyn v c cuon tu xc nh cc mc nc tnh ton v kch thc ca knh ng thi phi xtn cc yu cu ca cng trnh u thuyn. Knh vn ti thy thng c thit k chotu thuyn c th i li theo hai chiu. Dc knh cn b tr cc bn bi nhng v trthun li.

7.10. Nh my thy in, trm bm

7.10.1. Vic la chn kiu nh trm ca nh my thy in, trm bm cn phi thc hintrn c s so snh ch tiu kinh t - k thut cc phng n, c xt n cc iu kin sau:

a. m bo cho nh my lm vic t hiu qu cao;

b. m bo cng trnh v thit b lm vic an ton, tin cy v thun li trong khai thc(thng xuyn v tm thi);

c. m bo i lng ct nc tc ng ln cng trnh v thit b cng ngh ph hp vitnh ton thit k;

d. V tr nh trm trong b tr tng th cm u mi v kiu ca cng trnh dng ncchnh l hp l;

e. Ph hp vi dng t nn;

g. To thun li cho thi cng xy lp v cng tc phc hi - sa cha sau ny.

7.10.2. Gii php b cc phn di nc ca nh my thy in, trm bm phi tnh nbin php chia nh trm thnh cc n nguyn. Kch thc ca n nguyn tu thuc vokch thc t my, dng t nn, gii php kt cu ca phn xy dng, bin dng chophp.

Cho php dng kt cu lin khi (khng chia ct) cho ton b phn di nc ca nhtrm khi c lun chng tin cy. Kch thc sn lp my phi din tch sp t ccchi tit tho (lp) t mt t my ln nht v mt my bin p chnh. Cn tnh n khnng s dng mt phn din tch ca gian my gim din tch sn lp my. Trong nhmy ngm cn phi trit thu hp din tch sn lp my bng cch tn dng ti a dintch trn mt t tho lp.

29


30/35

7.10.3. Khi thit k phn nh trm ca nh my thy in kiu lng sng, kiu k p,phi xem xt cc phng n b tr nh trm tch ri hoc kt hp vi cng trnh x mthoc x su, b tr t my ng hoc t my ngang. Vi nh my thy in kiu ngdn cn phi thit k nh trm ng ring bit dng h hoc ngm, hoc b tr gian mykiu ging vi cch sp xp t my thnh mt hoc hai hng.

Khi c lun chng tha ng, nhng nh my thy in t trong khe ni hp c th btr t my thnh hai hng hoc theo mt cch sp xp thch hp.

7.10.4. Kch thc phn di nc ca nh my thy in, trm bm cn phi ly mccn thit ti thiu xut pht t kch thc phn thng nc ca t my v b tr trangthit b theo yu cu cng ngh. Vic b tr cc phng sn xut, phc v v ph tr khngc lm tng kch thc phn di nc ca nh trm. Kt cu phn ngp nc phic quy cch ha trn tt c cc n nguyn ca t my.

7.10.5. quan st tnh trng phn di nc ca nh my cn phi b tr cc ging vhnh lang quan st. Trong hnh lang nh my thy in, trm bm cn d tr hai li ra.Cc li phi c cu thang ring cch ly vi cc phng b tr bn trong nh my. nhging hoc li vo ca nh my ngm cn b tr cao hn mc nc ln nht h lu0,5m; ng thi phi c np kn nc (hoc ca) hnh lang khng b ngp.

7.10.6. kim tra v sa cha bung tucbin, bung ht v ng x cn phi b trhnh lang tiu nc, ca cng tc v li i ring cch bit vi cc phng ca nh my;phi d kin thit b bm nc loi tr kh nng nh my b ngp do s c.

7.10.7. Cc ca nhn nc phi b tr cc khe lp t li chn rc, thit b dn rc,ca van sa cha, ca van vn hnh chnh hoc ca van sa cha - s c v.v... Phi b tr

ca van sa cha - s c cui ng dn cp nc cho mt vi tucbin v trc ngdn vo bung ca mi tucbin.

7.10.8. Khi thit k lp bc (o) ca gian hm ngm, tuynen cn phi tun th nhngyu cu ca cc tiu chun thit k ng hm thy cng tng ng.

7.10.9. Khi thit k nh trm ngm, phi d kin nhng hnh lang v ging giao thnglin lc c th c gii ha vic vn chuyn thit b, vt liu v i li ca nhn vinqun l. ng thi phi d kin li i b hoc cu thang tng li thot ra bn ngoi chocc nhn vin qun l khi c s c.

Nu c th nn thit k hnh lang vn chuyn nm ngang. Hnh lang v ging vnchuyn phi ni vi sn lp my. ng cp lin lc cn kt hp b tr trong hnh lang vging vn chuyn.

Trong nh trm ngm phi b tr h thng thng gi m bo cho nh my hot ngbnh thng.

7.10.10. Cc phng sn xut ph (bao gm c h thng du), khi khng c yu cu cbit cn phi b tr chng trn mt t.

7.10.11. Thit b phn phi in p ca my pht v nhu cu t dng, trm iu khintrung tm trong trng hp t ngm cn b tr kt hp trong gian my nhng khng

30


31/35

c lm tng kch thc mt bng chnh. Trng hp cn thit c th lm ngch ring b tr thit b v my mc.

7.10.12. Ch thy lc trong tuynen tho vi mi trng hp khai thc phi duy tr ch chy n nh c p hoc khng p. Ch chuyn i t c p sang khng p hocngc li trong tuynen tho ch c php xy ra trong mt thi gian ngn khi c lun

chng tha ng.

Phi d kin a khng kh vo tuynen tho trong mi ch lm vic.

7.10.13. Khi thit k trm bm phi m bo cp lng nc theo yu cu ca biu dng nc.

Lng nc cn v biu dng nc c xc nh thng qua tnh ton cn bng thyli ton h thng c xt n:

a. Cc thng s thy vn ca ngun cp nc;

b. Cc thng s tnh ton ca h thng thit k: lng nc cn cp v ch dng nc,tn tht lng nc trong h thng bm chuyn, kh nng dn v iu chnh ca hthng, s khai thc c chp nhn v.v...;

c. Lu lng ca ngun cn li x v h lu phi p ng yu cu cho cc h dngnc v yu cu bo v mi trng.

7.10.14. Khi thit k ch lm vic ca cc trm bm c cng sut ln hn 10.000KW,cn xem xt kh nng s dng mt phn hoc ton b cng sut trm vi t cch l mth tiu th iu chnh cng sut b ca h thng nng lng.

7.10.15. Khi thit k kt cu b x ca trm bm cn to ra ch chy thun bngcch lm tn dng chy, phn b li v gim nh lu tc.

7.11. H cha nc

7.11.1. Khi thit k h cha cn phi gii quyt vn di dn ti nh c, n b thithi sn xut nng nghip; Bo v t nng nghip khi b ng ngp; Bo v bng binphp cng trnh hoc di di cc im dn c, cng nghip, vt kin trc, di tch lch skin trc, ng x, ng ng dn du kh, ng dy ti in, thng tin lin lc v.v...;Cht dn rng, v sinh lng h; Khai thc ti nguyn khong sn; to iu kin khai thcvn ti thy, thy sn; Bo v v s dng hp l ti nguyn nc, thy sinh vt, rng v

cc ngun ti nguyn khc.

7.11.2. Khi thit k h cha cn phi:

a. Lp cc Bo co nghin cu nh gi tc ng mi trng v d bo v s thay i mitrng sinh thi xung quanh vng h v lu vc do vic hnh thnh h cha c xt ncc yu t thy vn, a cht, a cht thy vn, ng thc vt trn cn v di nc,nng nghip, sinh thi v cc yu t khc, trong c vic lp d bo v cht lngnc, ti to b, s bin i ca mc nc ngm v cc tnh cht ca t theo tiu chunhin hnh;

b. Tnh ton phm vi mt thong ca h cha, vng ngp thng xuyn v vng bnngp c th khai thc;

31


32/35

c. D kin cc bin php khc phc khi than bn v cc khi vt cht khc b y ni khih cha tch nc.

7.11.3. Dung tch bi lng ti thiu ca h cha c xc nh tu thuc vo cp ca hcha nu trong bng 2.2. Thi gian dung tch bi lng ca h cha b lp y trong iukin bnh thng khng c t hn quy nh nu trong bng 7.1.

Bng 7.1. Thi gian tnh ton dung tch bi lng ca h cha b lp yCp ca h cha Thi gian tnh ton dung tch bi lng

b lp y

Cp V, IV 50 nm

Cp III 75 nm

Cp II v I 100 nm

Ch thch:

1. Dung tch bi lng ca h cha xem nh b lp y khi cao trnh b mt bn ct lngng trc tuyn chu p t bng cao trnh ngng ca nhn nc chnh.

2. Qu trnh bi lng ca h cha cp I, II cn xc nh thng qua tnh ton thy lchoc th nghim m hnh.

3. C bit, khi c lun chng kinh t - k thut tha ng c php chn thi giandung tch bi lng nh hn quy nh bng 7.1. Trong trng hp ny nht thit phic bin php hn ch bn ct lp trc ca nhn nc bng gii php cng trnh nhxy dng thm cng x ct hoc c bin php no vt nh k. V tr, qui m cng xct ca h cha cp I, II c quyt nh thng qua th nghim m hnh thy lc.

7.11.4. Trong trng hp dng chy ma l c lng nc tha phong ph cn phi xemxt phng n b tr cng x ct gim bt dung tch bi lng, tng dung tch hu ch.Cng ny c kt hp lm nhim v dn dng thi cng v rt nc h khi c nguy c s

c.

7.11.5. Lu lng, lu tc, ch vn hnh ca cng x ct ty thuc vo c tnh bnct cn x, tc rt nc cho php ca h cha sao cho m bo y c bn ct lngng trc cng v h lu m khng gy ra tnh trng st mi cng trnh t v b dc.

7.11.6. Mc nc thit k ln nht v mc nc kim tra ca cc h cha lm nhim vcp nc, pht in c xc nh trn c s iu tit l phn dung tch t mc ncdng bnh thng tr ln. Khi h c t dung tch phng l th mc nc ny c xcnh trn c s iu tit l phn dung tch t mc nc phng l tr ln. Lng nc x

v tho qua cc cng trnh trong tuyn chu p ca h cha phi tnh ton theo m hnhl bt li nht v nh l hoc tng lng l c xt n kh nng xy ra l kp do nhhng ca ma bo (nu tng xy ra trong vng D n).

7.12. Cng trnh bo v h cha v h lu cm u mi

7.12.1. Phi d kin cng trnh bo v h cha v h lu cm u mi ( bao, cngtrnh gia c b v.v...) nhm bo v ti a cc vng t c gi tr, cc i tng kinh tquc dn (thnh ph, x nghip cng nghip, t nng nghip, ci thin iu kin v sinhca ao h v.v...) khi b ng ngp v l b.

7.12.2. Vic thit k cc cng trnh bo v c thc hin theo cc tiu chun thit ktng ng hin hnh.

32


33/35

7.12.3. Khi tiu nc cho vng c bo v cn phi tnh n kh nng iu tit ti chmt phn dng chy gim bt quy m ca trm bm.

7.12.4. Khi thit k gia c b phi d bo s chuyn dch v xi su lng dn (nu c), sti to b v s m bo n nh chung ca c on tuyn phi bo v.

7.12.5. vng t c bo v khi b ngp ng, cn phi d kin thit lp mng li hkhoan quan trc din bin ca nc ngm.

7.13. Cng trnh cho c i v cng trnh bo v c

7.13.1. Khi thit k u mi thy li trn sng, h cha hoc ao m ni a vng cgi tr thy sn cn phi d kin xy dng cc cng trnh cho c i, cng trnh bo v c. n thit k cc cng trnh ny cn ph hp vi yu cu, tiu chun bo v ngun lithy sn.

7.13.2. bo tn ngun c d tr trong khu vc, cc cng trnh cho c i phi bo m

ng cho loi c qua li thng xuyn hoc qua li theo ma.

7.13.3. Khi thit k cng trnh ly nc ao h nui c cn phi d kin t cc dng cchuyn ngnh ngn nga c lt vo cng trnh ly nc.

33


34/35

Ph lc A

Danh mc cc cng trnh ch yu v th yu

A1. Cc cng trnh thy c xp vo cng trnh ch yu gm:

a. , p cc loi.

b. Tng bin, tng chn, cng trnh cho c i trong tuyn chu p.

c. Cng trnh nhn nc, ly nc v x nc, thot nc.

d. Knh dn cc loi v cng trnh trn knh.

e. Trm bm; Trm thy in; ng dn nc; Tuynen.

g. B p lc v thp iu p.

h. Cng trnh gia c b v chnh tr sng; Cng trnh thng tu (u thuyn, nngtu, p iu tit).

i. Cng trnh thy cng trong t hp xy dng nh my nhit in.A2. Cc cng trnh thy c xp vo Cng trnh th yu gm:

a. Tng phn cch.

b. Tng bin v tng chn khng nm trong tuyn chu p.

c. Cng trnh x d phng.

d. Cng trnh gia c b nm ngoi cm u mi; Cc cng trnh bo v c.

e. Cc ng mng cho b mng lm nghip, g cy xui v h lu.

Ch thch: Tu thuc mc tn tht c th gy ra khi b h hng hoc kh nng xydng li gp nhiu kh khn, mt s cng trnh th yu khi c lun chng thch ng c

th chuyn thnh cng trnh ch yu.

Ph lc BH s iu kin lm vic ca mt s cng trnh thy

Cc loi cng trnh v cc loi nnH s iu

kin lm vicm

1. Cng trnh b tng v b tng ct thp trn nn t v nacng.

1,00

2. Cng trnh b tng v b tng ct thp trn nn . a) Khi mt trt i qua cc khe nt trong nn 1,00

b) Khi mt trt i qua mt tip xc gia b tng v hoc i trong nn c mt phn qua cc khe nt, mt phn qua nguyn khi.

0,95

3. p vm v cc cng trnh ngn chng khc trn nn 0,75

4. Cc mi dc t nhin v nhn to 1,00

Ch thch: Trong cc trng hp cn thit, khi c lun chng thch ng, ngoi cc h snu trong bng, c php ly cc h s iu kin lm vic b sung xt ti c im

ring ca cc kt cu cng trnh v nn ca chng.

34


35/35

Documents

31TCXDVN 285_2002 quy dinh ve thiet ke CT thuyloi