Mot so giai phap trong khai thac nUdrc ngam nham giam thieu ha thap mat dat tai khu viTc tp. Ho Chi Minh
Some solutions to the underground water exploitation low low to minimize the surface area in Ho Chi Minh city
Ngay nhan bai: 16/12/2016 Ngay stj^ bai: 5/01/2017 Ngay chap nhan dang: 5/02/2017
TOM T A T :
Khai thie niffic diidi dat (NDD) se dan d&i ha thiip nnfc nafic hoac h^ mtfc ap li^c nilfic ngam. Neu khfing co giai phap phii h(;fp se din dfin phi vd cin bing dia tang vi lam cho mat dat bi svp llin. Si^p lun mat dat gay nhQng hiu qua nghiem trpng ve kinh te, xa hfii. Bdo cio trinh biy hai giai phap giim thieu h?
thip rai/c NDD khi khai thac ntlfic bing bai gieng:
- Xiy di/ng bai gieng khai thac d ndi cfi ngufin niffic bfi cap;
- Tfii ifu hoa Iuu lUi^ng nUcFc tai cac gifng khai thac.
Tii khda: nUfic diffii dit, st^p tiin mgt dit, bai gieng, tfii uu hfia.
luu lU^ng nUfic
ABSTRACT:
Exploitation of ground water (groundwater) will lead to lower water pressure or lowering of groundwater levels. Without appropriate measures will lead to disruption of the stratigraphy and make ground subsidence coUapsed. Ground subsidence caused serious consequences on the economic and social development. The report presents two solutions to reduce the lowering of groundwater extraction wells water park:
- Construction Yard exploitation wells in areas where water recharge;
- Optimization ofthe flow of water in wells.
Key words: groundwater, land subsidence, beach wells,
optimization, water flow
Nguyin Thinh Nam Bfi Xiy dung Nguyin Xuin Man D?i hoc M6-Dia chat Hi Nfii
Nguyen Thanh Nam, Nguyen Xuan Man
MdoAu
Khai th^c nudc dudi dat (NDD) se ISm cho tang chisa nudc bj co nin lai, do: i) ha thip muc nudc din dfin h? miJc hp life trong dia tang; li) dc phin tiJr hat dit da xip xfip chat hOn ihm cho ciung trong dat dh t3ng len, 16 r6ng giim. NhCmg the ddng tren se ihm cho mat dat vj vong xuong. Khi khai thhe nUctc dudi dit quh nhi^u se Ihm cho chn bing dia tang bj pha v6, gay nen syt lun m3t dit. Di ngan ch3n hi^n tuOng nhy dn phhi khai thac phu hop: i) kh6ng khai thie vdi luu lupng I6n vuot gidl han cho ph^p; il) hoac ih bfi tri gifing khoan khai thdc trong khu VL/C sao chocd nguon bo trO d^ dcim bSo can bSng mUc nifdc.
Syp lun m$t dat gSy nhiJmg hau quS nghidm trong ve kinh te, xa hoi.
Bio cio trinh bay hai giii phip gihm thiiu ha thip mUc NDO trong khai thie nUde bing bai giing. Hai giii phip dd 1^ [3], [4]:
- Xay dyng bai giing khai thie d noi cd ngufin nudc bo cap:
- Tfil uu hda lUu lupng nudc tai cic giing khai thie.
I - XAY D\SNG BAI GI^NG KHAI THAC Ni/dc DiJOt DAT d Ndt C6
NGUdNBdcAP
Di xhy dyng cic cdng trinh khai thac NDD vdi viec bfi cip tU cic nguon khic phit cd cie dilu kiln sin cd cic nguon nudc tu nhien hoic nhan tao ben canh {sdng, hfi); ciu trOc dia chit thu>' v5n v i quan hi thuy life giiia nudc mht vh NDD thu^n lpi,
Thudng cd 4 cic kilu bfi c^p v^ quan he thuy lye giUa nUde m^t v i NDBni.p]:
Kiu 1: Pho bien trong ddi du im, dpc theo cic song Idn. Trong dieu kien tu nhi^n phan Idn thdi gian trong nim sdng, hfi dupc NDD cung cip, ddng chiy ngim hudng tif bd ra phfa sdng. hfi. Trong miia lu NDD tam thdi dupc nudc sdng, ho cung cip (Hinh 1 a). Si^ cung cip nay xiy ra d ddi ven bd, lim ddng ehiy ngim hUdng tU phia sdng, hfi ve ddi ven bd. Chieu r^ng ddi nay ty le thuin vdi dO idn cua, bien dp dao d$ng mife nudc song, hfi, hi s6 tham cila d i t . Khi cd cdng trinh khai thie ven bd vdi mUc nudc ha thip dudi muc nude sflng hfi (Hinh l.b.1) thi nudc song cung cip eho cdng trinh khai thie.
Kiiu 2: Phfi biin d cie vung thifiu im, viing ed ciu true thuin lpi d l nUdc mat quanh nim cung cip cho NDD. Vio thdi kl lu gli tii eung eip tang len (Hinh 1 .a2). Khi c6 cdng trinh khai thie ven bd Ihi sy eung cip cing tang (Kinh 1 .b.2)
Kieu 3: Dhc tnfng eho tafdng hop sU dao ddng muc niAic sflng khdng Idn. Do dg nghieng thuy lyc cua nUdc dudl dat 6 ddi ven sdng Idn n^n khdng cd sueung cip cOa sdng (Hinh 1 .a3). Trong ttidl ki lu, qui trinh Ihoat ciia nudc ducri dat khong nhCmg khdng bi dUng lai mi cdn ting 1 ^ do sy gia tang luong cung cap Cac cflng trinh khai thie ven bd da sd trudng hpp khdng ha thap dupc muc NDD xuong dudi mUc nudc mit nen khdng nhin duoc cajng cap tU phfa song, cdn niu ha thap xudng ducin muc nudc mit thi lupng cung cap ciJng khdng ding ki (Hinh I.b3).
Kiu 4: Quan he thuy lue giOia nudc mit vi nude cd i p nSm sau duoc
ngan cich l>di kSp iham nUdc yeu Da sfi tnfdng hpp muc i p lUc cua tang
chua nudc cao hon m u t nu6c m i t nen NDO se cung c i p cho nuoc mat b i n g cdch t h i m xuyen tUdudi len qua Idp tham yeu (Hinh 1^4). Neu mUc i p luc thap hon m u t nudc mat thi se x i y ra hien tupr>g nguoc lai. Khi co cdng trinh khai thie ven bd, mUc NDO h^ t h i p xufing dudi muc n i ^ mat thl nudc m i t se cung cap cho cdng Irinh khai thac bAng each t h i m xxryin qua cac kip t t i i m y i u nin luong bo sung khdng ldn (Kmh 1 i>4).
Thuc t i l n eho t h i y viec xay dung cdng trinh khai t h i e nudc t h i m Ipc ven b d cd hieu qua nhat l i tU c i c ngudn nudc mat c6 quan he thuy lue vdi nudc dudi d i t Iheo kieu 1 va kieu 2 m d t i tren d i y ; ddi vdi Ivieu quan he 3 p h i i d i p d i p de nang cao mUc nudc mat; cdn ddi vert kieu quan he 4 thl c i n khoan t h i m cac 16 khoan d i n nucic tUtren xuong.
Oai lupng t h i m t u e i c ngudn nudc mat dupe xac ajnh b i n g cdng
thUe thuy ddng lye nhUsau:Q = K.M.B.I; (1) Trong 06: Q-dai lupng t h i m tU sdng ho, m V n g ; K-hi so tham eua
dat da t i n g chUa nudc v i cua c i Idp bun set l i n g d p n g d d i y sdng hd.
m/ng; M- c h i i u d i y t i n g chUa nudc, m; B-chieu dai d u d n g b d , m; l-dp nghieng thuy luc. x i c dinh theo b i i u thUc sau:l = (Hi - H J / L ; trong d d : H,-dd cao muc nudc mat; Hi-dd cao myc nudc ducS d i t t^i cdng trinh khai t h i e ; L- k h o i n g c i c h tU ngufin nuoc mat den cdng trinh khai t h i e .
->^-
Hinhl Nlilfn9lujuqiianUlluiylifC9iibK[)f)vJnif6ciTUtI1],(2]:
a)-tnmg die (J ki*n lir nhitn (a 1 ~ a.4); b)-ca cing Irinh kl«i Et* vm bi (b 1 - b 41 Trong mflt d i i u ki^n t u n h i * n cu t h i thi eic d^i luong K. M, B khdng thay dfii, d i t i n g d^i lupng t h i m Q ngudi ta p h i i l i m t i n g d d nghieng thuy l y t I b i n g 2 e i c h :
C i c h 1: c h u y i n cdng trinh khai t h i e c i n g g i n sdng hd c i n g t o t t h i m chl d i t ngay d Idng sdng hd (hinh 2a).
C i c h 2: ha t h i p s i u muc nudc dudi dat tai cdng trinh khai thac, tuy nhi*n cung chi cd t h i ha thap dfin gidi h?n cho phep (hinh 2b).
Hinh I Ting «r>qh*ng itiuj luc (Jong itiim til sdng [2], |4]:
2.d-Oui]!^ cing tiinh klui thie irl phu 9in tdng, 2 J)-Ha thip siu m ^ NDD a c6ng trirdi khai thac
Cdng thUc t f i n g q u i t de t i n h tnjf l u p n g khai t h i e NDD cd d^ng nhu sau [2], [4]:
Qu = Q,„ + { V A / D + a(V,i /t) -I- Qc, (2)
Trong (2): Qu- triJr lupng khai thac, m V n g ; Qn> - trU lupng dflng tg n h i l n , m ' / n g ; V«, - trCr lUpng tinh d i n hfii, m ' Vn - trif luong Hnh trpng luc, m ' Qa - trU luong cufin theo, m ' / n g ;
t - thcri gian khai thac (thudng dupc han d i n h la 27 n i m =10" ngiy):
0 - he sfi xam p h a m v i o trU lupng t i n h t r o n g lue eho p h ^ p [ l i y b i n g 30% d o i v d i cac tang chUa nude khdng i p ) .
Cac dai lupng QBV Va^ Vo duoc hinh th^nh trong d i i u kien t y n h U a con trtf lupng Qtichi hinh t h i n h tnang qua trinh khai t h i e , khi ma do sy bpm hiit m u t nude dudi dat bi h? t h i p se ldi cufin ddng c h i y tU c i c phfa v i o ting c h i n nUdc khai t h i e ( t h i m xuy^n tU c i c khdi nudc m i t xudng, t h i m nghieng tir c i c tang chOa nudc k l can vao„), trong d d lupng t h i m xuy^n tir cac khdi nude mat trong mflt sfi dieu k i f n chiim ti trpng r i t kfn. Dd l i tiin de d i x i y dUng c i c g i i n g t h i m kich thich ven b d .
C i c tang chUa nude dUdi d i t Pleistocen, Pliocen tr&n khu vyc TP. Ho Chi Mmh dupe bfi c§p tif c i c ngufin chinh 15]: kfinh D f l n g , nudc sflng Sii Gdn, sdng Odng Nai. NUdc mUa c i i n g l i ngufin bfi c|ip Idn cho t i n g chOa nudc Pleistocen v i g i i n tiep c h o PlicKen trfin. Chinh v l v^y m i myc NDO dao d p n g Idn Iheo myc nudc c i e d d n g sflng, kinh Odng v i theo hai miia khd va mua. Nudc kenh O d n g cung c i p eho nudc dUdI dSt t i n g Pleitocen. Khi nude kenh Ddng d i n g cao thi mUc NDO d cie vl tri c i c h kenh 20-lOOm d i u d i n g cao. Khi x i y d y n g xong k i n h Dfli muc NDO dang l&n 2-2,5m so vdi chua xay d y n g kinh D d i . Nudc mUa l i ngufin bo trp NDO Idn. K h i o s i t mUc NDD eho t h i y , khi cd tr^n mua kio d i i 1 -2 g i d thi myc NDD d CO Chi t i n g tin 0,1 - a 2 5 m . V l miia mUa myc NDD cao hon miia khd tU 1,5-3,0m. Nudc sdng S i l Gdn cd quan hi thuy lyc vdi NDO r i t tot: khi nudc sdng d i n g cao thi bfi e$p cho NDO, ngupe lai khi nudc sdng can thl NDD l^i cung c i p cho sdng.
Luong nude bfi c^p eho NDO tang Pleistocen tU c i c ngufin bfi c i p chinh n h u s a u [5]:
-TU kinh Odng l i : QKD = q.L.1,0 = 0,55x285000 = 156750mVngiy;
trong dd: q - luu lupng nhd n h i t kinh D d n g eung c i p cho nudc dUdl flit = O.SSmV n g i y ; L - c h i l u d i i p h i n kenh chua bj x i m i n g h o i (400km -115km
= 28Skm) = 285000m; g i i tri 1,0 l i be rpng tinh t o i n , l i y b i n g 1.0m.
- TU Sdng Sai Gdn l i : Q^^ = KLW(Fs^ - F »g«^,)/M; trong d d : K - h * sfi I h i m cua Idp dat d i d i y sdng; K = l m / n g i y ; L - c h i i u dai do^n sdng cung c i p cho nude dudl d i t , L = 22500m; W - c h i i u rdng trung binh cua sdng, W = 8 0 m ; M - c h l l u d i y ldp t r i m tfch d i y sdng, M=4,0m; Fson, • myc nudc tren sdng, I3y trung binh t h e o tram quan t r i e Binh Duong l i 0,15m; F * , „ * , - muc nudc ngam ben sdng lay t n j n g binh nhi^u n i m t^l tram quan t r i e Q002 Binh My l i 0,0m. Thay s6 ta cd: Q I M = 1,0 x 22 SOO x80 X (0,15-0,0)/4 = 67.500mVngiy.
-Tif nudc mua l i : Q,„ = F.W, t r o n g d o : F- di$n tieh hUng mUa cila khu vyc TP. Hd Chf Minh; W- cudng d p cung c i p nude mua cho t i n g . Thay s6:Qm=30953amVngiy.
D l x u i t x i y dung b i l g i i n g , Quy hoach vj trf x i y dyng c i c n h i m i y khai t h i e nude nin Uu lien vi trf ven sdng, kinh, rach v i hfi chUa vi khu vyc dd ed ngudn cung c i p , bfi trp ldn cho tang chua nudc khai t h i e G l i m luu lupng khai thie NDO b i n g v l ^ khai t h i e . xUly ngudn nudc m i t Trong viing TPilfi Chi Minh tdn tai hai t i n g ehUa nudc 16 hfing trong cde t r i m tfeh D | t U b d i t t cd g i i tri khai t h i e tdt: t i n g ehUa nudc Pleistocen v i Pliocen (trfin, dudl). Hai t i n g n i y dupc bfi c i p nudc m i t tU kenh Odi, sdng Sii Gdn, sdng Dflng Nai, hfi thdng sdng. rach khic v i nudc mua.
K i t q u i quan trie ddng t h i i NDO cung x i c dinh duoc dflng t h i i thuy v i n , tUc l i viing dflng t h i l NDO bj chi phdi bdl e h i d d thu^ v i n cua sdng Sii Gdn, kenh Ddi va miia mua, miia khd. Trfin cp sd nghifin cUu c i c luin ciS khoa hpc v i d i e d i l m dia c h i t thuy van viing TPXd Chi Minh d l xuit xiy dung bai g i l n g khai t h i e nudc t h i m tpc dpc tbeo d i i ven b d sdng Sii Gdn, sdng Ddng Nai, c i c sdng khic v i c i c kinh trong khu vUc T h i n h phd, n h i l l i kinh Odng, Bii gieng dua ra c i n g g i n sdng thi d d nghifing thuy luc c i n g kin
va nhan dupc liAi lupng t h i m tU sdng cang nhieu. Cac k i t cfui tinh toan cho t h i y vdi dien tich nhU nhau n i u dat bai g i l n g s i t mep nude sdng thi luu i- Ucmg khai t h i e se t i n g 2A-3,0 lan so vdi bai g i l n g c i d i xa mep niidc sdng (khoing each xa tU BSO-SOOm).
T d m lai, cdng trinh khai t h i e nudc dat cac gieng ven b d l i m d t dang khai thac c d n g u d n b f i sung nhan tao e i n dupc i p d y n g rdng rai d Tp>t6 Chf M i n h . D i lam vific n i y thi v i m g ven b d eac sdng nfin quy hoach t h i n h edng vifin, khu du ljch, g l i l t r i . . . va xay d u n g cac cdng t r i n h Idiai thiic nude dudi dat.
11 - T d i U u HOA LlAJ LUONG CAC L 6 KHOAN TRONG C 6 N G TRlNH KHAI T H A C N U O C D l / O l D A T
D i t v i n d l : N h u chOng ta da b i i t d i i u kifin dia c h i t thuy van [OCCV) cOa m p t sd loai m d NDO khdng d d n g i i n d o sy bat d d n g n h i t v i t i n h t h i m , chiia nudc. SP d f i b f i trf cac Id khoan khai t h i e trong c i c t i u d n g hpp n i y t h u d n g khdng cd dang hinh hpc d i e t r u n g (dudng t h i n g , dudng t r d n , ludi, .v.v) m i cd d a n g phan b f i bat ky dang difin tfch. Van d l d i t ra l i nen khai t h i e tU mfii 16 khoan vdi luu lupng la bao n h i ^ de tri sfi ha t h i p m y c nUdc v i n n h d hem hoac b i n g tri sfi ha thap mUc nudc cho phfip m i t f i n g luu l u p n g khai t h i e cCia chiing dat g l i ^ i cpc dai. Day ehfnh l i nfli d u n g eOa b i i t o i n t o i Uu lUu luong khai t h i e c i c Ifi khoan.
T h i l t l i p bai t o i n tfii Uu luu lupng nude c i c 16 khoan khi vj t r i cua chung da b i l t
Viec nghien cUu c i c b i i t o i n tdi Uu trong OCTV ndi ehung v i d i e bl^t l i b i l t o i n t f i l uu h o i luu lupng c i c 16 khoan ciia cdng t r i n h khai t h i e khi da i n djnh vj t r i eiia chiing d i dupe J.K.Gavitch v i F.M. Botrever d i c i p , Nfli d u n g b i i t o i n la x i c dinh luu lupng c i c Ifi khoan khai thac nudc Qi d i sao cho t f i n g luu lUpng khai t h i e Q i trong t h d i gian khai thac t dat eye dai, khi m i tri sfi ha thap mye nude Si tai 16 khoan j Widng vupt q u i tri sfi ha t h i p m y c nude cho phfip [S]i. Luu l u p n g cua cac 16 khoan cd t h i thay dfii tU 0 d i n Qmu ( g i i trj Qmu p h u thude v i o hfi sfi d i n nude cOa t i n g ehUa nude tai vi tri d i t Id khoan. c i u triic ciia n d v i d i e tfnh ky t h u i t cua m i y bom). Di dan g i i n h o i , g i i t h i i t c h i t lupng nudc d i m b i o va khdng p h i i d l c i p d i n gidl han v i chat luong nudc (dp k h o i n g h o i , t h i n h p h i n h o i hpcv.v).
Vdi dieu kien trfin b i l t o i n dUcK t h i i t lap n h u sau: x i e djnh luu I- Upng cda c i c 16 khoan khai t h i e nude Q, (i = 1 , 2 3 _ k) d l tfing cua chung d^t eye dai. TUc l i [4]:
F ^ Z Q
(3)D f i n g t h d i p h i l tuan theo c i e gidi h^n:
S , ( t ) < [ S I i , (4) 0 S Q, < Q « « ; (5) Trong cae cdng thUe tren' F - h i m mye tifiu; i, j = 1 , 2 _ , k l i sfi t h U
t y v i sd 16 khoan khai t h i e nudc. G l i t q S) phy thudc v i o d i i u kifin OCTV cua t i m g vung, luu l u p n g Ifi khoan Qi va thdi gian khai t h i e t Ddi vdi t i n g chUa nudc v d h^in g i i tri S, dupe x i c d j n h theo cflng thUc (6) hay (7). Ofii vdi nudc cd i p m f i i quan hfi (7) t h u d n g la mfil quan hfi tuyen tfnh giila tri sd ha thap 5, v i luu lupng 16 khoan [4].
(6)
Si = Z Q . a „
(7)Trong dd- f^- sUc can t h u ^ lyc khdng t h U nguyen; T - he so d i n n- U6c (mVng); a, * h i m i n h hudng cOa id khoan t h U i d i n thU j cd tfnh d i n tfnh tham, chiia nUde, loai bifin, k h o i n g c i c h tU bien d i n ehiing h o i c k h o i n g c i c h glCTa c i c 16 khoan. Ve mat t h u ^ luc n d chfnh l i sUc e i n thuy luc cda nude d i n 16 khoan; x i c dinh Iheo cdng thUc:
a, = ft2T, (8) G i i t n a „ v i mat v i t I;? l i trj sfi ha thap m y t nude trong 16 khoan t h U
j d o i n h h i i d n g khai t h i e cua Id khoan t h U I vdi luu lUpng b i n g m d t dcxn
vf. Biet ap cho phep xac ^ n h S,(t) d o i vdi t i t c i e i c Id khoan t u o n g t i e . GMM han (4), (5) bieu dien d u d i d a n g b i t phucmg t r i n h v i b i l u thUe S,{t) d u p c viet n h u he p h u o n g t r i n h dai sfi t u y i n t f n h .
M d t so tac g l i x i c d j n h Si theo cdng thUc sau day [4J:
S = ( l / 2 k m ) j Q , l n l ^ ; (9)
Trong do: k- he sfi t h a m ; m - c h i l u day l d p d i t da; r, - k h o i n g c i c h tU 16 khoan t h U i d i n 16 khoan t h U j ; khi 1=] t h i r, ban kinh fing Ipc cua 16 khoan,
TU (4), (5) v i (6) ehiing ta nhan dupc b i t p h u o n g t r i n h v i dieu kifin giiA han [4]:
H a m t 6 i U u : F = Qt + Q 3 + Q j + . . . + Q k —> M a x , (10) Cac rang b u d c
a.,Q, + a , j Q i + + a,tQi < [S]i (10.1)
a„Q, + anQi+ ...„+ a^Qi < [Sh (10.2)
a3iQ.+ai2Qj-(- + ajiQk < (SJj (10.3)anQ, + a.jQj-i- -1- ao,Qk < [S]i, (lO.k) O i i u k i ? n : 0 < Q, < Q««; i = 1,2,3 k (11) G l i tri cua h i m i n h hudng a^ duoc x i c d j n h n h u sau:
- TU mflt trong k 16 khoan, t h i d y Id khoan t h U n h i t ( N l ) dat luu I- u p n g duy nhat, c i c I6 khoan cdn lai xem nhU b i n g k h d n g ;
- X i c dinh g i i In S, eho t i t c i c i e 16 khoan t u o n g Ung vclii a, - B i n g phucmg p h i p t u o n g t u tlnh cho t i t c i c i c 16 khoan cdn lai (t=2,1=3, . . . , i = k ) se t i m dUpc nhUng gia tri cfln lai cfia ham i n h hUdng a^, va nhan dUpc (8).
O i l vdi tang chiia nudc co ap, vd han, khi khai t h i e kfio dai, h i m i n h hudng a, ed t h l t i n h theo cdng thife [4]:
a, = (0,183/T)lg(2,25at/r,'); (12) Trong d d : T- h ^ sfi dan nudc , m V n g ; a - h ^ sfi t r u y i n i p , m V n g ; t -
t h d i gian b o m khai t h i e , n g i y - d e m ; rp - k h o i n g c i c h tU 16 khoan j d i n c i c ifi khc»n edn lai, m ; khi j = i t h l rj, =r» = d u d n g kinh fing Ipc ctia 16 khoan h i i t nudc (thudng b i n g 0,2m -0,4m).
B i i t o i n thiet lap dupc d i e trUng bdi h i m muc tifiu F v i t i t e i c i c gidi han la t u y i n t i n h vdi c i c t h f l n g sfi tdi Uu Qi v i dupe t r i n h b i y n h u tiai t o i n quy hoach tuyen tfnh. N l u ham muc tifiu hay m d t trong n h d n g gidi han l i phi t u y i n so vdi Q thl he p h u o n g trinh (9), (10) l i b i i t o i n quy hoaeh phi t u y i n . Trong m d t so trUdng hop h i m phi t u y i n cd t h l dupc thay bdi h i m t u y i n tfnh t i m g k h o i n g t h l quy hoach phi t u y i n ducjc thay the bin quy hoaeh tuyen t l n h .
G i i i b i l t o i n tren b i n g n h i l u c i c h .
Mflt trong phUcmg p h i p g i i l l i d i m g p h u o n g p h i p simplex.
Sau d i y trinh bay ngi d u n g g i i i b i i t o i n tren bSng p h u p n g p h i p Simplex.
O l l i m v l f c nay ta v i i t lai b i i t o i n d dang [4]:
H i m t d i u u : G = - F = - Q i - Q j - Q j - . . -Qk —^ M m , (13)
" ang ea so 1 X / Q
X,
"•
X Q a., a, a,
Q.
a„
'"
1 - < 1 -
, x>
X.
• G a . , a., C = - 1
atu 1 a>.
' C . = - l Q.
a'!
a.i d ' l
a w d o C . = - l
Q.
a i l ais a »
aMs am C
- i Q-
1 ai>
1 a,.
1
a . . a . .
B»1S1 B, B; B I
B . B.
y~^,
Cac rang buoc.
+ a i i Q ,
0 2 . 2 0 1 7 & n i i i i i » «
aiiQi + a n Q j + ..._+ aaQw + Xj = [Sjj a a i Q i + a i j Q j + ..._+ a a Q t + X j = ( S l 3
a i . Q i + a u Q ) + . - + ai*Qi, -t-X^^ [S]»
O i l u kien: 0 < Q, < Q««; 1 = 1,2,3 k; (15) Lap b i n g Simplex cd dang sau d i y ( b i n g 1):
B i i n dfii b i n g c o s d theo nguyen t i e sau d i y :
- Chpn cdt cho phfip: cflt chiia g l i tri t u y ^ t dfii C Idn n h a t Gia t h i l t dd l i cflt s (cflt t d d i m ) .
- Sau khi cd cot eo sd s ta di tfnh cac gia tri cua cdt n i y theo cdng thUc-aB=bya;j=l,2^.,k.
- Chpn h i n g cho p h ^ p : h i n g chiia gia tri nhd nhat tU eac ajs tfnh trfin d i y . G l i thU d d l i h i n g m (hang t d dam).
B i l n dfii b i n g ea sd theo c i c budc sau:
4-tinh y l u t f i cho p h i p : auj thay b i n g BMS = l / a u i ; + c i e y i u tfi ciia l i i n g cho phfip: a u, = au /aus;
+ c i c y i u t d cua cflt eho phfip: a ,i = - ajs / a u i
+ che y l u tfl cdn lai bao gfim h i n g t y d o B va hang G tinh nhU sau:
aj>=a)i-(ais.au,)/aM
+ Thay do! vj trf cila b i l n sfi Qs trong cflt s cho bien XM trong hang m, B i i n doi c i c bude t i i p theo n h u trong c i c bude trfin d i y eho d i n khi t i t e i c i c y i u t d eua hang G d i u khdng i m (iing vdidcX.>0). Khi d d c i e g i i trj B^ d cflt cudi Ung vdi c i c X, 2 0 chmh l i nghidm cua b i i t o i n tfil Uu.
B i n g Simplex cudi ciing ling vdi glal dOfin b i i n dfii t h u k v i e i c y l u tfi cua h i r i g G l i C i khdng i m cd dang ( b i n g 2)-
t h i p muc nude cho p h i p tai c i c 16 khoan cd t h l l i y n h u sau:
[Sl,=IS]i=[S]i=50m.
Dua v i o (12) v i c i e sfi l l ^ u d i cho x i c d i n h dUpc g i i trj h i m i n h h- u ^ g an ( i = 1 , 2 , 3 : j = 1 , 2 , 3 ) l i n g vdfl luu l u p n g l i y b i n g 1000 m V n g .
B i i toan tfii Uu h o i dupc bieu d i l n b d i hfi p h u p n g t r i n h sau [4]:
G = - F = - Q i - Q ) - Q 3 - > • m i n 10,07 Q, + 6,845 Q: + 4,578 Q j -I- X, = 50 6,845 Q, + 10,07 Qi + 4,414 Q j -I- X; = 50 4,578 Q j + 4.414 Q j -i-10,07 Q j + X j = 50
0 < = a < = Q»-«
X , X I va Xj - l i e i e b i l n sfi p h u k h d n g a m dUa v i o theo phuong p h i p Simplex d e b i t p h u o n g trinh d a n g (14) t r d t h i n h p h u o n g trinh.
Q/X Q I Q ] Q i
Qk G = -F
X, a^ii a';i aSi
aV,
C ,X l aSi a':.- aS)
a'w C,
X I a ' l i a'ji a'li
a'o C,
Xk.
c,
X., a ^ I a'M
aV
a'w C .
B=[S]
BS BS Bfl
BS
Nghi$m tdi uu tUong Ung l i : Q, = BS
G l i lr| toi Uu h i m : G = - F = (BS + BS + BS + ...+BS i + BS) = Mm V i F = - G = -(BS + BS + BS +...+BS. + B'O = Max.
Trong trudng hpp b i i t o i n nhieu bien th) vi$c g i i i tren d i y l i r i t l i u v i m i l k h i n h i l u thdi gian Chfnh vi v i y m i n h i i u chuong trinh g i i l da dupe l i p . Sau d i y Ung d y n g mflt trong c i c chucmg trinh tlnh da ed sSn d l tim nghiem tdi Uu,
B i l t o i n trfin dupc thiet l i p theo m d h1nh c h u i n cua b i i toan l o i n quy hoach t u y i n tlnh nhU sau:
F = - X c , Q , - . M i n ;
X a Q < B , ;
0 < Q, < Qn«^c, > 0.
TU d i y cd I h i g i i i theo chucmg trinh tinh cua Biii V i n Tuan, Nguyen Mlnh Phuong hay theo Maple 9.5 cho ket q u i nhanh chdng. Sau d i y l i Ilnh t o i n minh ho9 sfi:
Vf d y : D l cung c i p nUdc cho m d t xl n g h i i p ngudi ta da khoan 3 l6 khoan khat t h i e cd dudng kinh fing loc: rii = r j i = r i ] = 0,2 m. T i n g chUa nudc i p l y c vd han ed b l d i y trung binh l i 30m. Ap lUe trgn m i i t i n g chiia nude l i SOm. TU t i i lifiu hut nudc thf nghidm [11] da xac dinh dupc h^ sfi d i n nudc T=220 mVng, he so t n j y i n ap a = 2,25x10* mVng. Cic Ifi khoan dupe bd tri theo dinh eda tam g l i c vdi k h o i n g each n h u sau: r u = r „ = 300m; r , = i i , = 400m v i r., = i„ = SOOm. Thiri gian khai t h i e l i t
=10* n g i y dfim (tucmg duong 27 n i m ) . Theo t i i lieu t h i m d d , tri sfl ha X/Q
X, Xl X, G = -F
Q i G = -F
Qi 10,07 6,845 4,578 -1,0 -0.440 0,039
Cb 6.845 10,07 4,414
•1,0 -0,025 0,047
Q j 4,578 4,414 10,07
•1,0 0,129 0,027
B 5 0 5 0 50 0 3.129 - 7 3 9 7 Ldi g i i i t h e o p h u o n g p h i p Simplex cho c i c n g h i d m : Qi=2046, Q)=2204 v i Qi =3129;
Fn« = QT = Q I + Qi + Qi = 2046 + 2204 + 3129 = 7379 m V n g . Ldi giai tfii Uu theo Maple 9.5 cho c i c n g h i d m : Qi=2.067; Qi=2.222; Q j = 3.051; F ™ = 7341 m V n g . So s i n h ket q u i g l i l t h e o Simplex v i d i m g c h u o n g trinh Maple 9.S cho t h i y sal k h i c khdng d i n g ke. Sai sfi l i : As= {(7379-7341 }/7341].100%
= 0,52%.
I l l - K ^ L U A N
1-Khai t h i e nude dudl d i t tat y e u l i m c h o m y c nude n g i m g l i m h o i c mUe i p lyc g l i m . Trong c i hai t r u d n g h p p trfin dan d i n sy h? t h i p m§t dat. D l g i i m t h i l u lun syt m^t d i t can cd bign p h i p khai t h i e nUdc dudl d i t sao cho v i n d i p Ong luu l u o n g c i n t h i l t m i mpc nude n g i m khdng ha t h i p q u i gidl h^n cho phfip.
2-Bio c i o trinh b i y hai g l i l p h i p khai t h i e nUde dUdi d i t n h i m g i i m t h i l u ha t h i p m$t d i t d d l i :
+ X i y d y n g bai g i l n g g i n sflng, hfi hay n g u f i n nudc t y nhifin khie d i d i m bao b f i c^p ngufin nudc d u d l d i t .
-I- Tfii Uu hda luu lupng khai t h i e eua c i e g i i n g khai t h i e trong b i l g i l n g n h i m d i m b i o lUu l u p n g khai t h i e cyc dai m i d f l h^ t h i p mire nudc khdng vupt g i i tri cho phfip.
TAIUEUTHAMKHAOCHINH,
|1) Bolrever Ph.M., 1978, Lf thuyit vd phuang phdp thUc hdnh linh trSIUpng khai Ihdc mSdc di/diSdt. NXB • L6ng dSf, MaWtovs, Bin ti^ng Nga,
1211.K. Gavilch, 1988, Thiiy ddng luc HXB' L6ng flir, MaCtcova. Bin tifng Nga.
13] A.A, KonopdianKep, E,H, laxepva-Popova, 1983. liin sup ml^t ddt do khai thdc na» ngdm nw L6ng dif. Malncowva. Bin lieng Nga.
14] Nguyen Xuin Man. 2008 "Uy dung mang quan trdc ldn mdi ddi do Idial Ihdc node ngSitf.
ti t i i Khoa hoc cip Vi^n Khoa hoc va Cong nghi Viit Nam.
15], Trin H6ng Phu. 2006. Bio cio difu tra dia d i i t dA tin vung TP.HCM, Lien doin Dja chit Thiiy vin - Dia chit Cong Trinh mien Nam,
[6]. V,fl.lomta[lze, 1979, Oia chit cing tnnh -Bia chit dOng luc cflng irlnh, Nhi xuit bin EM hpc v i Trung hoc chuyen nghifp, Hi Ngi.
[7]. N,A.TiaJt6vich, 1997. CohpcdSt, Nhi xuit ban Hflng nghifp. Hi N^i, [Sl Vo Ihi bm Loan 2004. Die difrn ilgng thii thuy hoi nudc dudl d i l t ^ ndng (< 100m) o i l W»ivucn#thanhTPHCM,Df t i l nghien oSli khoa hoc cipimen9,KhcB Oia (hit-Tn«ngCHI«IR
[9]. Ta M c Thinh, Nguyfn Huy Phuong. 2002. Co hpc d i t , Nhi xuil bin xiy d ^ , Hi Nfi.
IlOLTfinVinVifl 2004. Cim nang (fing cho kysu dia ky thuit NXB Xiy d ^ Hi Nfl.
[11]. Bg mfln DCa-DQV&MT 2007. Til lifu thi nghifm ca ly i l i l 6 khu v\fc TP.HCM, Khoa Dia chit - Troiing Dal hoc Khoa hoc Tu nhien TP HCM
