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B nng nghipv pht trin nng thn

----------S : 109 /2001/Q-BNN

Cng ho x hi ch ngha vit namc lp - T do - Hnh phc

------------------------------------H Ni , ngy 16 thng 11 nm 2001

Quyt nh ca B trngB Nng nghip v pht trin nng thn

V vic Ban hnh tiu chun ngnh : 14TCN 101- 2001- Ging gim p Quytrnh k thut thi cng v Phng php kim tra, nghim thu.

--------------------------------

B Trng B Nng Nghip V Pht Trin Nng Thn

- Cn c ngh nh s 73/CP ngy 01 thng 11 nm 1995 ca Chnh ph quynh chc nng, nhim v, quyn hn v t chc b my ca B Nng nghip vPht trin nng thn;

- Cn c Php lnh cht lng hng ha ngy 24/12/1999 ;- Cn c Quy ch Lp, xt duyt v ban hnh tiu chun ngnh ban hnh

km theo quyt nh s 135/1999- Q- BNN- KHCN ngy 01/10/1999;- Theo ngh ca ng V trng v Khoa hc Cng ngh v CLSP,

Quyt nh

iu 1.Nay ban hnh km theo quyt nh ny tiu chun ngnh : 14TCN101- 2001- Ging gim p Quy trnh k thut thi cng v Phng php kim tra,nghim thu.

iu 2. Tiu chun ny c hiu lc sau 15 ngy k t ngy k

iu 3.Cc ng Chnh vn phng B, V trng V Khoa hc cng nghv CLSP, Th trng cc n v lin quan chu trch nhim thi hnh quyt nhny.

KT. B trng B Nng nghipv pht trin nng thn

Th trng

( k)

Phm Hng Giang

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B nng nghipv pht trin nng thn

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Cng ho x hi ch ngha vit namc lp - T do - Hnh phc------------------------------------

Tiu chun ngnh14TCN 101 -2001Ging gim p - Quy trnh k thut thi cng

v Phng php kim tra, nghim thu

(Ban hnh theo quyt nh s: 109/2001/Q-BNN ngy 16 thng 11 nm 2001ca B trng B Nng nghip v Pht trin nng thn)

1. Quy nh chung1.1.Tiu chun ny quy nh cc yu cu ca quy trnh k thut thi cng, phngphp kim tra cht lng thi cng v nghim thu ging gim p c kt cu ging lcc loi ng lc lm bng thp khng r hoc ng nha PVC c kh nng chng nmn, c bn thu lc v cng tng ng nh quy nh cho thp khng r.yu cu v vt liu, sn xut vt liu, thit k, duy tu bo dng ging c quynh trong cc tiu chun tng ng.1.2.Ging gim p trong tiu chun ny l ging c lp t chn pha ng,sau p lm gim p lc nc l rng nn bng cch cho thot nc theo hnhthc t chy v ma l, kim sot qu trnh thm v ngn nga xi ngm v ctchy lm mt n nh nn.1.3.Phn loi Ging gim p:

1.Theo iu kin thi cng, chia lm hai loi: Ging o v Ging khoan.2.Theo iu kin lm vic, chia lm hai loi: Ging hon chnh - l ging

qua ton b tng cha nc v t ng lc trn ton b chiu dy tng cha nc;Ging khng hon chnh l ging ch khoan v t ng lc mt phn trong tngcha nc.

Tiu chun ny ch quy nh cho ging gim p loi ging khoan (c gitt l ging gim p).1.4.Cu to ca ging gim p bao gm: ng lc, ng chng, ng lng, ct lc scp, ct lc th cp, ng bo v ming ging (xem hnh 1.1).

ng lc l ng c lm bng thp hoc nha PVC c l ngn ct voging nhng cho nc thm qua; ng chng l phn ng lin (khng c l) lmbng thp hoc nha PVC, c lp c nh trong ging, ni trn ng lc ngn

khng cho ct chy vo ging, n nh thnh v ming ging; ng lng l on nglin khng c l ni di ng lc c tc dng chn ct, to khong khng yging cha cc ht ct lng xung do chng xm nhp c vo ging trong qutrnh ging lm vic. Khc vi ng chng, ng chng tm l ng kim loi dng n nh thnh ging trong qu trnh khoan v s c rt ln khi ging trong qutrnh kt cu ging; Ct lc l ct c sng chn cp phi ht hp l theoyu cu ca thit k, dng chn lp vo khong khng gian vnh khn xungquanh ng lc v ng chng c tc dng lc ngc, cho nc thm vo ging d

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dng nhng ngn khng cho ct t nhin ca mi trng xm nhp vo ging. Ctlc s cp chn lp t y ging khoan, xung quanh ng lng, ng lc v 1 m trnon ng lc; Ct lc th cp chn trn ct lc s cp.

Hnh 1.1. Cu to ging gim p.2. Quy trnh k thut thi cng ging gim p

Quy trnh k thut thi cng ging gim p bao gm cc cng on: 1- Khoanto l kt hp xc nh a tng; 2- Kt cu ging; 3- Thi ra lm thng thongging; 4- Bm kim tra; 5- Hon thin ging.

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2.1. Khoan to l kt hp xc nh a tng.2.1.1.Cng tc khoan to l phi tin hnh bng phng php khoan xoay, thi rabng nc l hoc dung dch chuyn dng t phn hu. Theo ng knh gingthit k, nn khoan ging thnh hai cp: khoan ly mu xc nh a tng v sutng cch nc (cp ng knh b); sau khi t su thit k th tin hnh khoandoa m rng (cp ng knh ln) t ng knh thit k nh nu trong iu

2.1.10, 2.1.11 v 2.1.12.2.1.2. Trong qu trnh khoan to l, phi nh v my khoan, thp khoan thngng bo m ging khoan thng ng, cn i. Nu dng my khoan t hnhth phi chn bnh xe k c nh my khoan.2.1.3.Cho php s dng phng php thi ra bng nc l khi khoan cp ngknh nh nhng my bm phi c cng sut ln y c "dung dch ct-nc l" ln khi ming h khoan v to dng chy ngc p lc gi thnhh khoan. Trng hp h khoan su v nc khng y c ct th ln khiming h khoan th phi dng mi khoan c km theo ng hng.2.1.4.Phi p dng ch khoan hp l i vi cc lp t khc nhau:

1.Khi khoan trong tng ct phi gim p lc khoan ng thi tng s vngquay v tng tc bm cho hp l;2.Khi khoan trong tng t st th tng p lc khoan v gim tc vng

quay cng nh lu lng nc ra;3.Khi khoan qua cc lp ct ht trung, ct ht th c ln si, phi thng

xuyn ko mi khoan ln lm sch ct trong ng hng.2.1.5.Trong qu trnh khoan xc nh a tng, hip khoan khng qu 1m. Cchhai mt ly mt mu lu v mt mu th nghim bng thit b ng ly mu chuyndng; Trong tng t st ly mu bng ng mu n c bi, trong tng t ct lymu bng ng khoan nng i hoc nng ba.

Vic thit k ging gim p trc khi thi cng ch l thit k in hnh; Thitk chi tit, hp l ng lc, hiu qu ging s thc hin khi c ti liu chnh xc atng ti hin trng. Mt ly mu s quyt nh chnh xc khi xc nh atng, ly mu cng dy cng tt, c bit su nghi c s thay i a tng.2.1.6.Ly mu, bao gi, vn chuyn v bo qun mu phi theo tiu chun VitNam TCVN 2683 - 91. Mu lu phi bc trong ti nylon buc kn, b trong cc ca khay g chuyn dng, trong thi gian ang hin trng phi k cao v chechn, khng b t hoc ngp nc. Mu lu ch c hu b khi nghim thu hthng ging gim p a vo s dng sau 2 nm v phi thng qua Hi ngchuyn mn t vn trc khi trnh cp c thm quyn quyt nh.2.1.7.Mu chn th nghim phn tch thnh phn ht phi cch u theo su,

c tnh i din cho lp t khoan qua, khng chn cc mu c th.2.1.8. Trong qu trnh khoan phi m t chi tit a tng v: Tn t, mu sc,thnh phn thch hc v thnh phn cp phi ht; cht (i vi ct) v trngthi (i vi cc loi t dnh); Mc ng nht v thnh phn, mu sc v trngthi, cc tp cht trong t; S tiu hao ca dung dch khoan; Quan trc mc ncxut hin v mc nc n nh trong ging. Vic m t, ghi chp phi tin hnhtheo tng hip khoan d gp lp t dy c mu sc, thnh phn v trng thi ca

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tng hip khoan t khc nhau; Phi m t v gi tn t theo tiu chun Vit NamTCVN 5747-1993.2.1.9.Sau khi khoan t su thit k, n v thi cng phi lp bn v ct a tngging khoan c xc nhn ca ch u t T vn thit k lm cn c thit k chitit ng lc v ng chng.2.1.10.Ch c tin hnh khoan doa m rng chun b kt cu ging khi c bn

v thit k chi tit do T vn thit k cp. bo m ging khoan trn u v thng ng, cn chn ch khoan doa

hp l: Tc vng quay s 1, p lc khoan nh nht v lu lng nc ratng hp l khng ph v thnh ging khoan, bm sch mn khoan trc khivo hip mi; Khoan doa hai ln, ht mt hip th ko ln doa li trnh to ccng xon.

Khi khoan doa m rng ging chun b kt cu, nn s dng dung dch tphn hu theo ng nng quy nh, m bo n nh thnh ging khoan.

Trong trng hp khoan doa c s dng ng chng tm, sau khi khoan doaxong cn ra sch ging bng cch bm nc qua cn khoan xung st y ging;

Khi s dng dung dch khoan t phn hu, sau khi khoan xong cn bm lu thngbng nc l ra sch dung dch c v thay bng dung dch mi cng cthnh ging khoan ri mi tin hnh kt cu ging.2.1.11.Tu thuc vo a tng, cn khoan su hn y ng lng mt on cn thit cha mn khoan lng ng trong qu trnh kt cu ging, khng mnkhoan ngp ln phn ng lc lm gim hiu qu ging.2.1.12.Trong trng hp gp ct chy y tri trong ging khoan th tu sugp ct chy, chiu dy ca lp ct chy v mc tri trong ging khoan m cth chn mt trong cc gii php sau: tng c ca dung dch hoc chng bngng chng tm.2.2. Kt cu ging.2.2.1.Sau khi ging khoan to ng yu cu thit k, tin hnh kt cu ging,gm cc thao tc: th ng lc, ng chng, ct lc s cp v th cp, bm trm vaximng-bentonit. Trong qu trnh lp t ng lc v ng chng, phi lp vt nhtm theo ng khong cch nh trong n thit k; Cn lp c nh vt nh tmdi cng, cc vt nh tm pha trn ch lp cht sau khi ni ng v iu chnhnh hng dn iu 2.2.8.2.2.2.Phi chun b y vt liu, thit b v nhn lc t chc thi cng lin tccc cng on, trong cng on th ng lc, ng chng, chn ct lc s cp vth cp cn thc hin vo ban ngy, trng hp hon thin cng vic m phiko di sang ban m th phi c nh sng cn thit v c s chp thun ca T

vn thit k v Ch u t.2.2.3.ng lc, ng chng c ni v th dn vo trong ging tng on mt chon ht theo ng n thit k. C th ni sn trn mt t thnh mt ct ri thmt lc vo ging khoan khi chiu di ca ct (ng lc v ng chng) nh hnchiu cao ca thp khoan.2.2.4.Nn s dng loi my khoan c cng sut v trng lng ln, thp caov c hai rng rc cp thi cng lp t ging thun li, gim thi gian th nglc, ng chng hn ch cc tc ng gy sp thnh ging khoan.

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Khi ging c khoan v n nh thnh bng ng chng tm th cho php thct lc trc tip t trn ming ging, u xung quanh khong vnh khn gia ngchng v ng chng tm. Trong qu trnh th ct lc s cp v th cp, ng chngtm c rt dn ln nhng phi bo m chiu su lun ngp trong ct lc 1m.2.2.13.Sau khi th ct lc s cp t cao trnh thit k, tin hnh ht nc t trongging lm n nh ct chn quanh on ng lc. Ch nn dng loi my bm

cng sut trung bnh to dng thm nh chy vo ging ct sp xp n nhxung quanh ng lc. Trong qu trnh bm, cn theo di lin tc cao b mt ctchn; Khi b mt ct chn n nh, khng h thp na th ngng bm v th ctb sung cho bng cao trnh thit k, sau tip tc th ct lc th cp. Quy trnhth ct lc th cp, bm cho n nh cng ging nh i vi th ct lc s cpxung khong vnh khn xung quanh ging sau khi bm ht nhiu gi v b mtct lc th cp thc s n nh khng cn kh nng h thp c na.

Kt thc thao tc th ct lc th cp v ct n nh th tin hnh bm vaxi mng-bentnit trm ging khoan.

Va ximng-bentnit c a xung ging bng phng php bm dng;

u di ca ng phu phi c mng ch T trnh trng hp va pht trc tipvo ct lm xo ng lp ct lc. Ngay sau khi phun va ximng-bentnit xongphi bm nc t trong ging ra kim tra kh nng va xm nhp vo ging. Khithy c hin tng va ximng-bentnit xm nhp vo ging th phi bm lin tcnhng bm chm (bm vi lu lng nh) cho n khi nc bm ra khng cn lnva th dng bm, thi gian bm khng c qu 12 gi.2.3. Thi ra lm thng thong ging.2.3.1.Thi ra lm thng thong ging c thc hin sau khi hon tt vic ktcu ging cho ging thng thong, nc thm vo ging d dng, bao gm: bmdng vt cn, nhi nc, bm pht tia, bm nn kh.

Cc thao tc cn tin hnh phi hp v an xen t c hiu qu ti a,theo yu cu k thut ca cc thao tc thi ra ging m bo khng lm rchmng ng lc gy hng ging.

Nn dng phng php bm dng vt cn thi ra tm ging khoan trckhi phi hp cc phng php thi ra khc, gm thao tc: th cn khoan xungging gn st y, dng my bm ca my khoan (my bm dung dch khoan) bmnc sch lin tc vo ging, nc cng vi mn khoan s tro ln khi mingging v c dn thot i m khng bm tun hon tr li ging.

Nhi nc l dng mt qu nhi bng g cng hoc kim loi ng knh nhhn ng knh trong ca ging 25mm, c l x p lc v c lp cc a da hoccao su ng knh xp x ng knh trong ca ging; Nn nhi dn t trn xung,

tng on hai mt mt, bt u t on cch nh ca ng lc 2m, mi on nhilin tc khong 5-10 pht tu a tng v mc bn ca ging, on cui cngcch y ging hai mt khng nhi trnh trng hp qu nhi ri chm vo yging lm bc y.

Phi treo qu nhi bng cp, khng bng cn khoan (thao tc nhi thng quacn khoan cng c th lm rch hoc bin dng ng lc).

i vi mi ging nn nhi khng t hn 3 chu k, ngha l sau khi nhi sutton b ng lc t trn xung, ngng nhi bm vt mn khoan v nc bn rakhi ging; Sau khi nc ln trong, li bt u nhi chu k tip theo thao tc

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nh chu k u. Nu sau 3 chu k nhi m nc ra vn c th tip tc nhi n khinc ra trong.2.3.2.Sau khi nhi nc kt thc, tin hnh bm pht tia v bm nn kh theo quynh di y. Thi gian bm pht tia ph thuc vo mc thng thong caging.

1.Bm pht tia l dng my nn kh di p sut cao thng qua mt ng

pht chuyn dng c l pht kh (thng c 4 l) nn mnh thng gc vo mnglc ra sch cc ht mn cn bm dnh lp nht cc khe rng ca mng lc theotrnh t bm t di ln. Thit b bm pht tia v p lc bm phi tun theo yucu ca h s thit k, ph thuc vo loi vt liu lm lc. Vn tc ca vi phtphi t 45-80m/s, p sut pht vo khong 14,07 kG/cm2i vi ng lc bng thpkhng g v 6,12 kG/cm2i vi ng lc bng nha PVC. Trong qu trnh bmpht tia phi xoay u ng pht v ko dn ln, bo m cho tia pht qut u tonb mt mng lc, nhng khng dng lu ti mt ch.

2.Bm nn kh c tin hnh sau khi bm pht tia. Khong cch gia ucui cn dn kh v y cn dn nc phi hp l bo m hiu qu bm. Khi

bm phi o lu lng v h thp mc nc. Ch tin hnh vic bm kim trakhi kt thc cng tc bm lm thng thong ging.2.4. Hon thin ging.

2.4.1.Vic hon thin ging bao gm: lp t ng bo v ming ging; ng thunc kt hp tiu nc chn v cc ng dn nc ra cc ao h ni ng; Lp tmng o lu lng; Trng c v lm v sinh hin trng.

ng thu nc kt hp tiu nc chn l on ng c c l v c baobi cc vt liu lc nh ct, si, vi a k thut, chy dc chn , ni gia ccging gim p thu nc thot ra t cc ging; ng dn nc l cc on ngkhng c l dn nc thot ra t h thng ng thu nc vo khu cha nc

theo n thit k.2.4.2.Lp t ng bo v ming ging c thc hin ngay sau khi lp t gingxong, cc cng vic cn li ch c php thc hin sau khi ging c bmkim tra theo quy trnh k thut c quy nh trong cc iu Mc 3 v t ccch tiu k thut quy nh iu 3.8.2.4.3.Cho php lp t ng bo v ming ging tm bo v ging, khi bm kimtra ging t cht lng quy nh iu 2.4.2 th tin hnh lp t ng bo v theo n thit k cng vi cc thao tc hon thin khc.2.4.4.Vic lp t cc on ng thu nc kt hp tiu nc chn phi theo ngbn v thit k; Kim tra cao trnh o rnh, cao trnh t ng bng my trc a

thng bng. Phi thi cng chiu dy cc lp lc ng bn v thit k, bo m ctkhng xm nhp vo trong ng.2.4.5.Khi lp t ng dn nc, phi kim tra cao trnh t ng bng my trc cthng bng. Sau khi lp, phi m cht.2.4.6.Lp t mng o lu lng ti cc v tr theo bn v thit k; nh v v nobu lng chc chn cc tm kim loi. Kim tra nm ngang ca cc cc cnh trnca thc o lu lng bng ng thu chun. y ca thit b o v im "0" cathu ch phi cng cao trnh nh trong ca ng dn nc v phi m bo tonb lng nc thot ra t ging gim p chy qua mng o lu lng.

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2.4.7.Sau khi hon chnh vic lp t ging, cn phi: thu dn v sinh, hon tr limt bng theo ng yu cu, trng c bo v chng xi.

3. Phng php kim tra cht lng thi cng v nghim thu

Trong qu trnh thi cng phi tin hnh kim tra tt c cc cng vic thicng, m bo yu cu k thut v cht lng. Vic tng kim tra, nh gi chtlng thi cng, nghim thu ging tin hnh bng vic bm kim tra theo quy nhc th di y:3.1. Thnh phn, ni dung, yu cu vic bm kim tra.3.1.1.Bm kim tra thu thp s liu v tnh ton hiu qu ging, lm c s nhgi cht lng thi cng ging. Tt c cc ging thi cng xong u phi c bmnc kim tra cht lng; Ch nhng ging t cht lng mi c a vo sdng, ging khng t cht lng phi honh trit trc ma ma l.3.1.2.Bm kim tra bao gm: bm git cp, bm kim tra 3 gi v 12 gi. Phibm git cp, bm kim tra 3 gi cho tt c cc ging; Bm kim tra 12 gi cho

mt s ging theo quy nh ca T vn thit k.3.2. Thit b bm kim tra v yu cu v lp t.3.2.1.Thit b dng bm kim tra bao gm: my bm, thit b o lu lng,thit b o mc nc, thit b kim tra hm lng ct.3.2.2.Nn dng loi my bm in chm trc ng, vn hnh bng mt in, chs dng my nn kh (trong trng hp c bit, phi c kin ca T vn thit kv chp thun ca Ch u t). Cn la chn loi my bm c lu lng, ct ncp lc tng ng vi lu lng, mc nc ng ph bin ca lot ging c bmkim tra khng gy ra p lc m trong ng lc; My bm phi c ng ctnh Q-H tng ng vi ch bm kim tra tng i phng m bo s thay

i lu lng trong qu trnh bm kim tra khng qu 5%.1.Vic la chn my bm, chiu su lp t trc khi bm kim tra phi cnc vo cc tr s lu lng, mc nc ng thp nht o c thi im cuicng ca giai on thi ra lm thng thong ging nu iu 2.3.1.

2.My bm (i vi bm in chm) hoc y ca ng dn nc (i vibm nn kh) phi c lp t su ti thiu 2m di mc nc ng thpnht, nhng phi cao hn nh ng lc t nht 1 m. My c treo c nh, chcchn trn ming ging, m bo n nh trong sut thi gian bm kim tra.

3.Trong thi gian bm kim tra, ngun in cp my bm phi lin tc vn nh v tn s v in p, nu cn th b tr ngun in d phng v m bo

thi gian thay th ngun in cho my bm khng qu 1 pht.3.2.3.Thit b o lu lng, bao gm: ng h lu lng v thng o lu lng.Nn s dng kt hp c hai loi m bo chnh xc o lu lng v n gintrong vic iu chnh khng ch lu lng bm n nh.

1.ng h lu lng phi c thang o ti 1 lt v phi c kim nh chnh xc trc mi t bm nc kim tra.

2.Theo lu lng bm, thng o lu lng s dng l loi mng trn hnhtam gic vung cn hoc hnh ch nht, kch thc m bo cc tr s ti thiu quynh cho loi thng ny v c ti thiu 3 ngn. Cc li chn sng b tr m bo

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ngn cui cng, trc ca ming x mc nc n nh c chiu cao mc ncchnh xc c ti 1mm. Thc o phi gn thng ng v tr tm thng, cchming x 0,5m v m bo v tr 0 trng vi v tr thp nht ca ming x.

3.Phi lp t van iu chnh, ng h hoc thng o lu lng v tr thchhp trn ng ng x ca my bm iu chnh lu lng bm. Thng o lulng phi t nm ngang v c kim tra trc khi tin hnh bm kim tra.

4.Phi m bo nc x ra khng tr li ging (k c bng thm lc) lmnh hng n kt qu quan trc mc nc trong ging bm v cc ging quantrc; Trong iu kin bnh thng, v tr x nc cch ging ht nc v cc gingquan trc ti thiu khng di 20m.3.2.4.Quan trc mc nc trong qu trnh bm kim tra, c th dng thit b t ghimc nc hoc thit b bo mc nc bng in (nh sng hoc ng h). Chiudi dy o mc nc ti thiu phi ln hn su t u bm t nht 5,0m vc khc vch ti milimt, c ghi di 0,5m v th t su tng mt. Phikim tra chnh xc ca thit b o trc khi tin hnh bm bng cch o chiusu mc nc tnh trong ging vi chnh lch kt qu o gia ba ln o lin tip

khng qu 1cm.u o ca thit b quan trc c th vo ging trong ng o nc bngthp hoc nha PVC, c ng knh trong ti thiu ln hn 1,5 ln ng knhngoi ln nht ca u o mc nc; ng o nc phi lp t su thch hpvi loi thit b bm s dng, i vi bm chm th y ca ng o cch nh camy bm khng qu 0,5m; i vi my nn kh th chiu su lp t ng o phinm di phn ho kh ca ng dn kh t 5m tr ln.3.2.5. Kim tra hm lng ct: nn s dng loi thit b kim tra trc tip kiuRossum hoc tng ng v c gn v tr thch hp ti ngay u on ra cang ng x ca my bm. C th ly mu nc kim tra hm lng ct theoquy nh ti iu 3.8.3, v tr ly mu nc pha mt di ca ng ng x vti v tr chy ri ca dng nc trong ng, mu nc ly vo thi im cui cagiai on bm kim tra.3.3. Yu cu k thut bm kim tra.3.3.1.Ch tin hnh bm kim tra vo ma khng c l, mc nc ngm khng bnh hng bi dao ng ca mc nc sng.3.3.2.Cng mt thi im ch c bm kim tra mt ging v trong lc bm kimtra th khng c khoan, o, thi ra hoc bm trong phm vi phu h thp mcnc ca ging bm kim tra.3.3.3.Phi bm lin tc trong mt ch bm (3 gi, 12 gi hoc trong mi cpca bm git cp) v khng ch lu lng n nh trong qu trnh bm. Phi hu

kt qu bm khi c bt c s gin on no, ch mc nc hi phc hon ton thmi bm li t u.3.3.4.Lu lng bm phi ph hp vi iu kin a cht thu vn. Lu lng thct ln nht c th ca tng ging c nh gi sau qu trnh thi ra lm thngthong ging v m bo mc nc ng cui giai on bm khng nm di 1/3chiu dy ca tng cha nc hoc 1/3 chiu di ca on ng lc c lp ttrong ging.

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3.3.5.Tr s h thp mc nc phi m bo 2m i vi ging bm v chnhs h thp mc nc gia cc ging quan trc lin tip khng di 0,1m.3.3.6.Khi tin hnh bm (tr trng hp bm git cp) phi quan trc mc nctrong t nht bn ging lin tip v mi pha cn ging bm v cc ging o, gingkhoan khc hoc mc nc ao h (gi chung l im quan trc mc nc) trongphm vi xung quanh ging bm (trong khong t ging quan trc th t n gingbm nc). Khi bm git cp, ch cn quan trc mc nc trong ging ang bm.3.3.7.Trong qu trnh bm kim tra phi ghi chp y din bin v mc nc,lu lng v cc thng tin cn thit khc theo biu mu Ph lc A.3.4. Chun b bm kim tra.

Cn tin hnh cc cng vic sau y:1.Trc khi tin hnh bm kim tra mc nc trong cc ging phi l mc

nc tnh trng thi t nhin, o ti thiu 3 ln mc nc tnh trong ging bm vti cc ging quan trc, mi ln cch nhau 15 pht trc khi bm; S dng cngmt mc c nh o mc nc tnh v mc nc ng trong sut qu trnh bmkim tra.

2.B tr t nht mt thit b o mc nc cho mi im d nh quan trcmc nc.

3. Tng kim tra tt c cc thit b, cng tc lp t v tnh n nh cangun in cung cp.

4.B tr nhn lc tin hnh o mc nc, lu lng ging bm vcc im quan trc tng ng theo thi gian (tn sut) quan trc quy nh ti iu3.5.

5.Kim tra trnh t bm kim tra (bm git cp, bm kim tra 3 gi v 12gi).3.5. Quy nh v thi gian (tn sut) o lu lng, mc nc.

3.5.1.i v bm 3 gi v 12 gi, thi gian (tn sut) o lu lng trong gingkim tra c quy nh nh sau:

Thi gian k t khi bt u bm, pht Khong cch gia cc ln o, pht0 60 5

60 120 10120 300 20300 600 30

600 kt thc 60

3.5.2.i vi bm 3 gi v 12 gi, thi gian (tn sut) o mc nc trong gingkim tra c quy nh nh sau:

Thi gian k t khi bt u bm, pht Khong cch gia cc ln o, pht0 5 15 30 2

30 60 560 90 10

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12

90 120 20120 kt thc 30

3.5.3.i vi bm 3 gi v 12 gi, thi gian (tn sut) o mc nc trong gingquan trc c quy nh nh sau:

Thi gian k t khi bt u bm, pht Khong cch gia cc ln o, pht0 5 0,55 15 1

15 30 230 60 560 90 1090 120 20

120 kt thc 303.5.4.i vi bm git cp, thi gian (tn sut) o mc nc, lu lng trong qutrnh bm quy nh nh iu 3.5.1 v 3.5.2 nhng thi im tnh t khi bt u

mt cp lu lng mi.3.5.5.o hi phc mc nc trong ging bm c tin hnh vi thi gian (tnsut) o nh iu 3.5.2 v 3.5.3 nhng thi im tnh t khi kt thc bm.3.6. Bm git cp.3.6.1.Bm git cp phi tin hnh cho tt c cc ging xc nh t lu lng caging, lm c s chn lu lng bm kim tra 3 gi, 12 gi hp l, bo m dngthm ti ging trng thi chy tng; Cc yu cu v bm git cp c quy nhnh sau:

1.S lng cp lu lng bm khng nh hn 4 cp.2.Lu lng bm ti a (Qmax) c xc nh trn c s kt qu s b v lu

lng, mc nc trong ging giai on cui cng ca qu trnh thi ra lmthng thong ging. Lu lng bm mi cp c xc nh trn c s Q max nhsau:

Cp 1: 25% Qmax;Cp 2: 50% Qmax;Cp 3: 75% Qmax;Cp 4: 100% Qmax.

3.Thi gian bm mi cp mt gi. Trnh t bm theo th t cc cp lulng tng dn. Phi duy tr s n nh ca lu lng bm ngay t thi im uca mi cp lu lng.

4.C th chn mt trong hai ch bm git cp: git cp lin tc hoc gitcp cch qung. Nu chn ch bm git cp lin tc th sau khi kt thc bm mt cp, tip tc tng lu lng t n cp tip theo; Khng c dng bmgia cc cp lu lng. Thi gian iu chnh lu lng mi cp cng nhanh cngtt, khng vt qu thi hn 5 pht u tin mi cp. Nu chn ch bm gitcp cch qung th sau mi cp lu lng, ngng bm ch mc nc hi phc honton mi c bm cp tip theo.

5.Phi o hi phc mc nc cho ti khi phc hi hon ton hoc ti thiukhng di 4 gi trong trng hp thi gian hi phc mc nc ko di.

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3.7. Bm 3 gi, 12 gi.3.7.1.Bm kim tra 3 gi, 12 gi thu thp cc s liu cn thit, xc nh ccthng s a cht thu vn c bn ca tng cha nc, phc v cho vic tnh tonhiu qu ca ging. Thi gian bm ca mi ch bm ph thuc vo iu kina cht khu vc trn c s s liu kho st ban u (h s nh nc v dn thulc ca tng cha nc), do T vn thit k quy nh, m bo:

1.Bm kim tra 3 gi, tin hnh cho tt c cc ging thi cng.2.Bm kim tra 12 gi, ch nh cho mt s ging i din, phn thnh cc

cm ging c cc iu kin v a tng, cu trc ging tng ng. Mi cm lachn mt ging i din bm kim tra 12 gi, do T vn thit k la chn.

3.7.2.Chn lu lng bm cn c vo kt qu phng trnh ng cong lu lngthc t ca tng ging xc nh t kt qu bm git cp, bo m dng thm voging ch chy tng.3.7.3.Qu trnh bm kim tra phi m bo lin tc, khng c ngt qung; Lulng bm duy tr trong sut thi gian bm kim tra c iu chnh v quyt nh

ti hin trng trong 5 pht u tin v m bo sai s khng vt qu 10% so vilu lng la chn. Trong sut thi gian bm phi duy tr lu lng n nh visai s khng vt qu 5% so vi mc lu lng c quyt nh giai onu.3.7.4.Kt thc bm kim tra phi tin hnh o mc nc hi phc tt c ccging quan trc v ging bm theo thi gian (tn sut) quy nh iu 3.5.2 v3.5.3. Thi gian o: T lc dng bm ti khi mc nc hi phc hon ton hoc tithiu bng thi gian tng ng ca mi ch bm trong trng hp thi gian hiphc qu di.3.7.5.Phi kim tra tt c cc s liu bm kim tra, x l cc sai s th trc khi

a vo tnh ton. Cc ging c cc sai s v lu lng, mc nc hoc b ginon trong qu trnh bm kim tra phi c loi b v tin hnh bm li t u.3.8. nh gi cht lng thi cng ging.3.8.1.Cht lng thi cng ging c nh gi thng qua ch tiu "hiu qu ging",k hiu l "" v lng ct ra theo nc trong qu trnh bm, k hiu l "m". Hiuqu ging , tnh theo phn trm, l t s gia h thp mc nc l thuyt (S lt)v h thp mc nc thc t (Stt). h thp mc nc thc t (Stt) c o trctip trong ging ht ti thi im kt thc bm kim tra. h thp mc nc lthuyt (Slt) c xc nh bng mt trong cc phng php sau y:

1.Phng php th (xem biu B.2 Ph lc B), p dng khi c t nht 3

ging quan trc v mt pha ca ging ht.T kt qu o h thp mc nc trong t nht 3 ging quan trc ln cnging ht v mt pha, v th S=f(r) trn giy bn logarit, trc tung t l thng(bng mt) biu th h thp mc nc S, trc honh t l logarit biu th khongcch t cc ging quan trc n ging ht nc tnh bng mt. Ko di on thngthu c v pha ging ht nc n ranh gii gia vnh khn ct lc v ct tnhin ca mi trng thm (ngoi suy kt qu). Tung ca im giao nhau caon thng ko di v ranh gii ngoi ca vnh khn ct lc chnh l h thpmc nc l thuyt.

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2.Phng php th suy din (xem biu B.1 v B.3 Phc lc B), p dngkhi ch c mt ging quan trc.

T kt qu o h thp mc nc trong ging quan trc v th S=f(t)trn giy bn logarit, trc tung t l thng (bng mt) biu th h thp mcnc, trc honh t l logarit biu th thi gian k t khi bt u bm, tnh bngpht. Trn biu ny xc nh S ng vi hai thi im t1 v t2sao cho t2/t1= 10v t2cng gn thi im kt thc bm cng tt. V h to S theo r trn giy bnlogarit, trc tung t l thng (bng mt) biu th h thp mc nc, trc honht l logarit (bng mt) biu th khong cch k t tm ging bm. Trn h to ny xc nh im A c honh bng khong cch t ging quan trc v tung l kt qu o h thp mc nc trong ging quan trc vo thi im cuitrc khi ngng bm. V on thng i qua im A ng thi i qua hai im chonh r1v r2sao cho r2/r1= 10 (im A nm trong khong gia r1v r2) v Sng vi hai im ny gp i gi tr S thu c trn. Ko di on thng thuc v pha ging ht n ranh gii ngoi ca vnh khn ct lc. Tung caim giao nhau ca on thng ko di v ranh gii ngoi ca vnh khn ct lc

chnh l h thp mc nc l thuyt.3. Phng php th - gii tch.Trn th trc tip S=f(r) nu im 1 iu 3.8.1 hoc th suy din

S=f(r) suy t th S=f(t) trnh by im 2 iu 3.8.1 xc nh S ng vi r1=10m v r2= 100m, ng thi ko di on thng thu c ct trc honh ti imA. To ca im A ng vi r = r0v S = 0. Xc nh cc thng s ca tng chanc T=0,366.Q/S; =2,25.T.t/r0

2. Trong T - dn thu lc, m2/ng; - h snh nc; t - thi gian bm , ng; r0- bn knh nh hng ca ging, l honh ca im A xc nh trn, m. Thay cc gi tr T v va tnh c vo cng thcsau:

S QT

Ttr

= 0 183 2 252

, lg ,

Trong : r - ly gi tr bng bn knh ca ging k c phn vnh khn ct lc, m.Gi tr S thu c chnh l h thp l thuyt.

Nu mi trng thm c ng nht cao (mi trng thm khng c ccthu knh, lp kp thm nc km) c th nh gi theo bt k mt trong 3 phngphp trn; Mi trng thm khng ng nht, nn nh gi theo phng php th.3.8.2.Khi nh gi cht lng thi cng ging, cn lu :

1.i vi cc ging khng hon chnh, c s bin dng dng thm vnggn y ging nn h thp l thuyt xc nh bng cc phng php nu trn cth c sai s kh ln, tu thuc vo t l gia chiu di ng lc v chiu dy tngthm nc. h thp mc nc l thuyt c th xc nh chnh xc hn bngcch t mt piezometer ln cn ging ht nc (cch ging ht khng qu 2m)v o trc tip h thp mc nc l thuyt trong ng piezometer ny.

2.i vi cc ging hon chnh, trong trng hp nghi ng kt qu tnh ton h thp mc nc l thuyt th cng c th kim tra li bng phng php o

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trc tip mc nc trong piezometer ln cn ging ht nh quy nh im 1 iu3.8.2.

3.Nu khi bm kim tra, mc nc trong ging kim tra h thp vt qu20% chiu dy tng thm nc th s nh hng ng k n dn thu lc catng cha nc, khi x l kt qu h thp mc nc phi hiu chnh theo cngthc sau:

S S S

Htth tdtd=

2

2

Trong : Stth- h thp mc nc thc t hiu chnh, m;St- h thp mc nc thc o, m;H - chiu dy tng cha nc khi cha bm, m.

4.Phi kim tra v x l ngay cc s liu th ti hin trng, hu b kt quv tin hnh bm kim tra li trong cc trng hp sau:a) Lu lng bm c s thay i vt qu 5%;b) Biu S=f(t), tr cc gi tr ban u, khng th hin ng ng c trng, cc

s o khng nm trn ng thng hoc gn thng;c) Biu S=f(t) l ng gy khc.3.8.3.Lng ct ra theo nc trong qu trnh bm c xc nh bng thit b nh nu iu 3.2.5 hoc bng cch quay ly tm mu nc ly t ng x ca mybm. Khi xc nh lng ct thng qua mu nc, phi ly ti thiu 3 mu nc,mi mu t nht 1 lt 3 thi im khc nhau vo cui thi gian bm, kt qu l gitr trung bnh ca 3 mu nc .3.8.4.Ging c nh gi thi cng bo m cht lng khi bo m ng thi 2ch tiu sau:

1. Ch s "hiu qu ging" khng nh hn 70%.2. Lng ct ra theo nc m khng ln hn 10 mg/lt.Cc ging bm kim tra khng t c thi ra v kim tra li, sau 3 ln

thi ra, kim tra m vn khng t th honh trit v thay ging khc vo ln cnging c.3.8.5.Phi lp h s hon cng ging gim p sau khi kt thc bm kim tra vhon thin ging. H s bao gm: Bo co hon cng km theo tr ging khoan ca chi tit cc thng s v kt cu, cu trc ging kt hp vi a tng dc trcging. Bo co hon cng phi nu y bin php thi cng to ging, kt cuging, thi ra lm thng thong ging; Chng loi vt liu s dng to gingnh: loi dung dch dng thi ra, khi lng v cht lng ct lc s cp v thcp, khi lng ximng-bentnit, cc c tnh k thut ca ng lc v ng chng,

ng v np bo v; c tnh v chng loi cc thit b bm kim tra, s kim trav cc kt qu bm kim tra; S b tr ging gim p, h thng ng thu, dnnc v cc ti liu lin quan khc.

KT. B trng B Nng nghip v PTNTTh trng Phm Hng giang k

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Ph lc AMt s biu mu s dng trong qu trnh

bm kim tra ging gim p

Biu A.1.

Biu quan trc mc nc trong ging bm/ging quan trcK hiu im o: Ging bm:V tr: im so snh cao :n v hnh chnh: Cao im so snh (m):Khong cch n ging ht: su mc nc tnh n im sosnh:Ngy bm: Ngi o:Thi gian bt u: Ngi kim tra:Thi gian kt thc: Xc nhn ca T vn gim st:

STT Thi giano

Khong cch tim so snh n

mc nc (m)Cao mc

nc (m)Ghi ch

M t thi tit, dinbin cc s kin trongqu trnh o, cc s ck thut nu c.

Biu A.2.

Biu ghi chp s liu o lu lng ca ging bm

Ging bm: Thit b o:V tr: Ngi o:n v hnh chnh: Ngi kim tra:Ngy bm: Xc nhn ca T vn gim st:Thi gian bt u: Thi gian kt thc:

STT Thi gian o Lu lng, l/pht Ghi chM t thi tit, din bin cc s

kin trong qu trnh o, cc sc k thut nu c.

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Ph lc B(Tham kho)Mt s biu s dng tnh h thp mc nc l thuyt trong gingkhoanBiu B.1. Biu h thp mc ncS=f(lgt)Ging quan trc RW81.5-02, khong cch n ging ht RW81.5-01 r = 30,5m

S Thi gian hthp

TT bm ht mc nc

(pht) (m)

to 0.000

1 1 0.007

2 2 0.030

3 3 0.068

4 4 0.097

5 5 0.120

6 6 0.1427 7 0.162

8 8 0.180

9 9 0.188

10 10 0.208

11 11 0.218

12 12 0.225

13 13 0.235

14 14 0.246

15 15 0.253

16 20 0.284

17 25 0.310

18 30 0.335

19 35 0.360

20 40 0.380

21 45 0.395

22 50 0.407

23 55 0.423

24 60 0.432

25 75 0.46026 90 0.48827 105 0.50528 120 0.51729 135 0.53530 150 0.55031 165 0.56032 180 0.568

Lu lng bm: Q = 6.5l/s = 561.60 3/ngS = S(100) - S(10) S2 S1 St

0.496 0.202 0.293

y = 0 .1274Ln (x) - 0 .0911

0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1

1 1 0 1 0 0 1 0 0 0

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Bi u b.2. Bi u h thp mc nc s=f(logr)

Biu S = f(logr) ca ging ht nc RW81.5 - 01

Ging Ging Mc nc Mc nc r Stt Sltht nc quan trc tnh ng (m) (m) (m) %

RW81.5 - 01 3.820 1.248 0.076 2.572 2.033 79.043RW81.5 - 02 3.766 3.198 30.50 0.568RW81.5 - 03 3.770 3.355 60.05 0.415RW81.5 - 04 3.750 3.449 90.35 0.301

y = -0.2438Ln(x) + 1.4047

0

1

2

3

0.01 0.1 1 10 100 1000

y = -0.2438Ln(x) + 1.4047

0

1

2

3

0.01 0.1 1 10 100 1000

Slt

Stt

h

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i u b.3.bi u suy di n S=f(lgr) suy t S=f(lgt) ca ging quan trc g n nht

Biu suy din S = f(logr) ca ging ht RW81.5 - 01suy t ging quan trc RW81.5-02

Ging Ging Mc nc Mc nc r Stt Sltht nc quan trc tnh ng (m) (m) (m) %

rw81.5 - 01 3.820 1.248 0.076 2.572 2.094 81.401rw81.5 - 02 3.766 3.198 30.50 0.568

S= 2S* = S(100) S(10) = 0.586 10.00 0.852 tg= S/(ln(100) - ln(10)) = 0.254 100.00 0.266

_________________________

y = -0.2545Ln(x) + 1.4378

0

1

2

3

0.01 0.1 1 10 100 1000

Slt

Stt

h

S

Stt