w" Thong tin khoa hoc cong nghe m o
NGHIEN ccira G I A M T H I E U NGCIY CO egc NOOC TIEM (m trong tidm Id khai dao dirdi hay gdn ki doi tirang chiifa niriHc
After providing the basic knowledge on the water breakout phenomena Including their reasons, their forms as well as the conditions for forming the water breakout, the authors propose some fundamental technical measures for preventing the potential water breakout risks at underground mines under or adjacent to the water bearing objects
TS. NGUYIN VAN CHI
Viin Khoa hge Cdng nghi Md-Vinaeomin GS.TSKH. IU. A. NORVATOV Viin VNIMI ( Liin bang Nga)
MR. EIJI. YAMASHITA, JCOAL (Nhit Ban)
Hidn tuyng xay ra trong qua trinh khai thde md h i m Id, khi gdp xult lp nude chay vdo 16 ed luu luyng tdng dyt biln, vi du, khi ddo Id chuin bj cd tilt didn Xm^ ma gdp xult ly nude vdi luu luyng Idn hen X m^/h ed t h i coi Id bgc nude.
Thyc t l . ddi khi bgc nude ldn biin eat, than, thdm ehi ca vdt lidu chlng Id, do Id bj sdp do.
Trong nhilu trudng hyp, bgc nude kdm theo ea bgc khi.
1. NhCrng nguyen nhan gay buc nuac trong md hdm Id
Bgc nudc thudng xay ra khi ddo Id gap phay hodc hang cdcta hay pha. hda dudi cae doi tuyng chira nudc, m|t nhu sdng, suoi, moong chii'a nudc, bai thai, hole cac i dii tuyng chira nudc ngim, I nhu ting dit, dd nirt ne chira . nude, thlu kinh cat chira
nude, ddi phd huy phay phd : sung nude, day bai thai tich
! nude. Id cu chira nudc, v.v Noi chung, trong khai thac md him Id, n l u khdng cd giai I phap phdng ngira hyp ly se i dd xay ra sy co bgc nudc.
i Tdm lai. xay ra bgc nudc i khong chf do qua trinh khai thae gap cac doi tuyng chu'a 1 nude tilm an trong Idng dat
hay trdn mdt, ma nguyen nhdn sdu xa, dd Id do vi phgm quy trinh khai thde khi khu khai thde bj anh hudng eua ede d i i tuyng ehira nude.
2. Phdn d^ng bye nu'd'e vd didu ki^n hinh thdnh
Trudc ddy, ngudi ta dd IJhdn dgng buc nude theo nguIn nude bgc, (tir cdc d i i tuyng ehira nude mat, nude ngim) vd theo dpng thdi luu luyng nude bgc (trir luyng tmh, trir luyng ddng...), tuy nhidn, kilu phdn dang ndy khdng ehi ra duye ban chit bgc nude. Theo IU A.
Norvatov [5], bgc nudc xay ra Id do mit edn bang thuy-dja- ea-md. ndn phan dang theo dilu kidn hinh thdnh bgc nude se chl ra ban chit tirng dang bgc dk ed ea sd phdng chlng.
Hinh 1 Id sa d l phdn dang bgc nudc theo dilu kiyn hinh thanh.
Bgc nude ehi xay ra khi h|i tg du cdc dilu kidn, bao g i m nguy ea (dilu kidn du) va xult hidn nhdn t l kieh thich, phd vd can blng thuy-<^a-ea-md.
Nguy ca xay ra bgc nudc duyc quy v l 4 dgng chinh: (1) do dp lyc nudc phd huy vdch ngan; (2) do nude chay qua khe nirt, hang hoc; (3) do dp
lye md tdng, phd huy vdch ngdn vd (4) do nude tich trdn ndc Id ehy.
Dang bgc nudc (1) thudng xay ra trong him Id, nhlt Id khi khai thde ting trdn ciing ngay g i n , dudi ddy d i i tuyng ehira nude mat. Bgc dgng ndy thudng gdy ra thidt hai Idn nhlt, edng trinh md bj phd hiiy.
Dang bgc nude (2) gan giong dang (1) nhung khde Id vdch ngdn ehua bj phd huy.
Bgc dang ndy thudng Idm ngap ham Id, kdo theo sy ha thip myc nude ngam trdn didn rdng xung quanh khai trudng (ddi khi di kdm vdi sgt dit).
Dang bgc nude (3) thudng xay ra khi khai thde d mire sdu vd nude ngim bgc vdo Id ehinh.
Dang bgc nude (4) khd phdn dodn do nudc tich dpng trdn ndc Id chy sau nhilu ehu ky phd hda, ha tran.
MQt s l trudng hyp bgc nude da gap d Viet Nam duac ting hap trong bang 1.
a) Bye do ap luc nu&c phi huy vach ngan (dang 1)
Dilu kidn hinh thdnh bgc nude dang ndy phg thupc vdo
KHCNM SO 1/2012* DIA CO MO
«
Thdng tin khoa hye cdng nghd nid
Nhdn t6 kich thich. ph^ ho5, n l min, mu-a i^n, 10 dflng dOt ngOt, s$p 66...
Bgc til' ap luc nu'6c phS huy v^ch nqSn
1 Bgc n u d c chdy qua khe mVt hano hAr.
D9ngbi,ic(1)
Bgc nwdc vd fl^t cdt tu cdc 16'p vung dit dd chua nu^c hay vdt thi nudc vd'i dp Ig'c du id'n phd huy trgng thdi cSn bdng 16'p vdch ngdn v6i hkm 16.
Bgc til' dp luc m6 phd huy
vdch nadn
D^ng bye (2)
Nu6c tu cdc 16'P chua nu6'c, 16 cO, d6'i phd huy, v^t t h i nu6'c tr6n b6 mdt theo cdc khe nut dSn nu6'c bgc vdo 16
Bgc nu6c tich trgn vdch 16 chcr phd hoa
D^ng bMC (3) Nudc vd ddt dd trong dut gSy chua nu6c, 16 cO, thdu kinh... dO xAp cao bgc vdo trong vCing gia tdng dp \\jrc m6.
D^ng bMC (4)
I
Nu6'c bgc tich dpng trong khoang h6c tdch I6p phia trfen khflng gian khai thde 16 chcr
Hinh 1. Sa di phdn d^ng bgc nw&e theo dieu ki^n hinh thinh Bang 1
Bdn chat cde d^ng bgc nw&c D^ng bgc nw&c (1): Ap luc nude Idn nhlt Pgh phd huy vdeh ngdn (bl ddy h) bgc vdo 16, phd hiiy cdc cfing trinh trong 16.
Dang buc nw&c (2): Nudc chay qua khe nirt, hang hoc ede ta, 16 eO, Idm ngdp mo.
Dang bgc nw&c (3): Ap luc mo cue dai phd huy vdeh ngdn.
D^ng bgc nw&c (4): Nude tich dpng trdn vdch 16 cha phd hoa, tilm I n nguy ea bye vdo 16.
Mgt si trw&ng hgp thw&ng gip & Vigt Nam - Pgh Tdng nhanh trong khi h kh6ng d i i d i n tdi bue (h=const)
Pgh Tdng nhanh trong khi h gidm ddn dan tdi buc
Pgh khong d i i trong khi h gidm dan dan tdi bue (Pgh=const) Pgh Khong ddi trong khi vdeh ngdn bi ddo thung ( n l min ...) Vung khe nut d i n nudc lan tdi b l mdt dia hinh
Vung khe nirt d i n nudc lan tdi ddy d6ng khii nude mdt - Ddo 16 vdo vung nirt nd ehua nude, hang ede ta t h l u kinh cat - Ap lue m6 dp cdt bun phd thiing vdeh ngdn bge vdo Id
- Ap luc md dp bun nudc trong phay bgc vdo 16 - Ap lue mo dp bun nude trong 16 eO bgc vdo 16
- Nudc tich dpng trong khe nirt tdch Idp bdn trdn 16 chy phd hoa Nudc tich dQng trdn vdeh gid bdn trdn 16 ehd phd hoa
tuang quan giQ'a dp lye nudc Idn vdeh (Pgh) vdi lye khdng cdt eiia vdeh ngdn (OK) vd b l ddy vdeh ngdn (h) giira h i m Id vdi d i i tuyng chira nudc. Cd t h i k l d i n mpt s l trudng hyp diln hinh sau:
Trudng hyp dp lyc nudc mat (Pgh) tdng dyt biln phd huy vdeh ngan vdi h i m Id, vi du ngay 3/7/98 mua lien tijc vai ngay 318mm don chiy vao moong lp via +110 Lp Tri-
Thong Nhat, ding cao khoang vao dudi va each Idng suoi 4 66m, phi thung diy moong mit. bj tdt ndc.
bijc xuong Id +53 phia dudi vdi luu lugng khoang 5400m^/h (xem hinh 2).
- Trudng hyp dp lyc nudc mdt (Pgh) tdng ddt biln khi khai ddo lam mdng vdch ngdn, vi dg, luc 21 h ngay 4/7/1982 mua 150mm tpo ra
lu Idn trong suSi Van Ldi trong „ ^ ^ 2. Moong Id via +110 Lo khi Id di cup 3 via 9 muc Tri ngiy 3/7/1998 tich day +100 khu 56 Mpo Khi, dao nw&c mwa bgc xuong Id+53
KHCNM s6 mon* DIA CO M6
I^Kk Thong tin khoa hoc cong nghe mo
Hinh 3. Sa do bge nw&c khi dp Hinh 4. Sa di bge nw&e khi dp Hinh 5. Sa do bge nw&e khi /(TC nw&e ngim = const nhwng Igx: nw&e ngim = const nhwng dp lyv nw&e ngam = const md ddo Id ehgc thing vdeh md ddo Id ehgc thing vdeh nhwng md ddo Id bdp vdo ngan a trin Id [5] ngdn & trg Id [5] thiu kfnh bun cdt [5]
\- i:'- ir:_:- - T ^ - - " ' ' I
i^upy^t^^...:.^"^
M.M iwr /•/.
i s I r- I ' l i K H i
-J
Hinh 6. Trw&ng hgp ving KNDN lan trwe tiep t&i ddy khoi nw&c mit
Hinh 7. Trw&ng hgp vung khe nwt dan nw&e cdt vdo tang ehwa nw&e, lien thdng thuy Igv vdn nw&e mat (Vdng danh) Tnrdng hyp tuang t y xay ra
d Mdng Duong vd Khe Chdm.
Trudng hap dp lyc n u d c khdng doi (Pgh= const) nhung khai ddo Idm mdng vdch ngan (h) ddn tdi bge nude, vi du, ngay 30/5/1981 d Mpo Khe, Id chg pha hda via 9b lam tgt long suoi Van Ldi.
Trudng h y p dp lye nude ngim khdng d i i (Pgh= const) nhung khai ddo thung vdeh ngan d ndc Id (hinh 3), n i n . 16 (hinh 4) hoac ddo vdo t h l u kinh biin cdt (hinh 5).
. b) Buc nu&c qua khe nut mng hoc, Id cu (dang 2)
Khde vdi dang (1). trong tardng h y p nay vdch ngan hau nhu khdng bj phd huy, chi CO nude mat hay n u d c n g i m
chay vdo Id qua khe nirt, hang hoe. Id eu,... d ddy Id khe nirt nhan tao, hinh thdnh sau ede vg no min hay phd hda todn p h l n . Khi k h l u than, phd hda, k h i i dd vdch djeh ehuyin b i l n dang, nirt vd, phdn ra 3-4 ddi (trong dd ddi sap do hdn loan d u d i ciing vd ddi ede khe nirt thang dirng ndm trdn gdp vdi nhau gpi Id viing khe n i i i ddn n u d c vd Id eon dudng ehinh d i n nude x u l n g Id. Thudng gap mpt s l trudng hap sau:
Trudng hap viing khe n i i i d i n nudc lan tdi b l mat dja hinh, khi dd kha ndng ehira vd d i n nudc trong viing tang ldn hdng tram, ngdn i l n so vdi dd nguyen khoi. Khi c h i l u eao vung khe nirt d i n nudc HKNDN
nhd han dd sau khai thde thi
Id cha CO nguy ea bge, ngdp vdo miia mua. Nhu trudng hap ha t i n g mire -50 md Hd Lam, trong ede ndm 1992.
1994, 1995 lidn tgc bj ngdp Id khi mua Idn, h o l e Id cha ea gidi hda via 8 Tdy Vdng Danh, khai thde dudi s u l i , thdng 7/2010, luang nude suoi chay vdo Id Idn d i n 380m^/h.
Trudng hap viing khe nirt d i n nude lan tdi ddy ddng k h i i nude mat (hinh 6), hoae eat vdo mot t i n g ehCra nude ddy vd tang ndy lai thdng thuy vdi khoi nude mat (hinh 7), khi dd chac chan khdng t h i to ehire khai thde duac.
- Trudng hap ddo 16 vdo khoi da nirt ne, hang cdcta, ddi pha huy, trudng hap nay luang nudc chay vdo Id ldn.
KHCNM s6 mon* DIA CO M6
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Thong tin khoa hoc cong ngh§ moftwNi^ffiHHHBSHKfii ''"•"^^^ji
..r''-.
Hinh 8,9. Sut dat sau khi buc nw&c md Phan Me 1998 va Idm myc nudc ngim quanh khai trudng ha thip nhanh chdng, ddi khi cdn xay ra sgt dit (hinh 8, 9, 10).
c) Bye do ip /{/c md phi thung vich ngan (dgng 3)
Bge dang (3) gilng vdi dang 1 Id vdch ngdn bj phd thiing khi bgc nhung do dp lyc md chir khdng phai dp lye nude. Theo IU. A. NorvaTov, dp lye md sau guang Id d mpt khoang cdch nhlt djnh dat gia tri Idn nhlt. N l u Idp dd vdch tai vj tri dp lye md dat gid tn eye dai (F^ax) mdng han xung quanh, lai tilp gidp vdi t h l u kinh chii'a biin, cdt (hinh 11)
Hinh 10. Sau khi Id -87 Khinh Hda bye nw&c (9/2011) hing lo^t giing nw&c dio trong nhi din bj mit nw&c thi Idp dd vdch se bj phd huy.
(tgt phay FA Mao Khd ngdy 20/3/1996). Khi ddo Id chuin bj md khdng khoan thdm dd trudc guang, phai ldp duac Idt cdt chi tilt cde Idp dd edeh nude, chira nudc ndm vdy quanh dudng Id trong khoang 10-50 met. Tai vj tri dp lyc md dat gid trj cyc dai (F^ax) giap vdi Id eu hay ddi phd huy phay nghjch eung xay ra bgc nude dang 3.
d) Bye do nu&c Uch dgng tren ndc Id (dgng 4)
Tardng hyp nude tich dyng trong cac khe nut. Id ring d ndc Id, sau khi phd hda, da vdch bj ha xulng, ding thdi
vdi sy tdch Idp, hinh thdnh cdc khoang, h i e (hinh 12). Do dd sdt hilt nudc truang nd co t h i ddng kin cdc khe kin vudng gdc vdi mdt Idp, Idm tdng tich tg nudc trong nhCrng khoang, h i e ndy.
D i i vdi Id chy khai thde than, vdi t i c dy tiln guang khoang 2 m/ngdy. thi ehu ky gdy vdch ca ban cd t h i den hang thang. tuang ung Id thdi gian tich nudc trong khoang hie, nhu vay, vdi guang 16 cha ddi hdng trdm met thi dii tinh t h i m cua dd vdch rit nho, v l n cd t h i tich tg hang tram met k h i i nudc vd d i n thdi d i l m thich hap se bgc vao 16
Hinh 11. Sa do bye bun cit vio Id do ip lyc md Hinh 12. Sa do buc nwac tich dgng trong khe , nwt vd khoang hoc tdch lap trong vdch Id chg [
KHCNM S6 1/2012* DIA CO M 6
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ehy. Chu trinh ndy se tdi didn eho cdc lan bgc tilp theo [1].
Trudng hap bgc nudc tich dpng trdn vdch gia tren noc Id cha. Trudng hyp ndy da xay ra d Id cha khu Ddng Binh Minh ngdy 30/10/2009, vdi luang nude d i n 7000 m^
3. Nhung giai phap giam thilu nguy c a bye nu'd'e.
Giai phdp trudc tien, dd Id t l ehire thye hiyn edng tdc quan trac dja chit thuy van, theo hudng d i n eua Tdp dodn Cdng nghidp Than-Khodng san Viet Nam (ban hdnh theo Cdng vdn 2827/CV-TM ngdy 28/4/2006). Theo dd, khi gdp sy c l bge nude, vide d i u tidn la dilu tra Idm rd nguydn nhdn bgc nudc, ding thdi thing kd lai, Idm ca sd nghidn eiru, phdn tich nguydn nhdn bge nude.
Mot so giai phdp dp dgng cho ede trudng hap eg t h i , nhu sau:
Trudng hap doi vdi cdc mo khai thde dudi cdc doi tuyng ehua nudc can dy tinh trudc dp lye nudc cue dai (Pgh) cd t h i xult hiyn. Tir dd tinh todn b l ddy Idp ngdn toi thieu giQ'a h i m Id vdi d i i tuyng chira nudc.
Ap lye nude gidi han Pgh 6\j/ge tinh theo edng thirc cua V.D. Xlexatev [1, 2]:
Pgh
= ^(^K-^-rh-rA
Vdi nhCrng bai thai, viyc do ap lye nudc Pgh khd han, c i n phai khoan tir tren b l niat xulng day de quan trac.
Trong nhQ'ng nam qua, Vien Khoa hye Cdng nghd Md- Vinaeomin (Vien KHCN Md) da thi cdng 15 Id khoan quan
trie dp lye nude loai ndy d viing Quang Ninh.
Ben eanh dd, phai cap nhat duye chilu ddy Idp ngdn cdch (h), lyc khdng clt eua vdch ngdn (OK) giCra him Id vdi d i i tuyng ehira nude.
B l ddy vdch ngdn (h) hodn todn ed t h i xdc djnh bdng trie dja md, doi vdi lyc khdng eat (OK), eIn djnh ky ily m i u ca ly 6k xae djnh, dong thdi phai tinh d i n dp giam bin eua vdch ngdn do anh hudng eua khoan n l min, sung nude vd cdc tde nhdn phong hda.
Trudng hap d i i vdi ede md khai thde g i n , dudi ede d i i tuang ehira nude, ed liyn hd thiiy lyc vdi sdng, suli, eIn dy tinh 6uge dinh lu eao nhlt ed t h i xult hidn, khi ed mua Idn, mua lidn tgc nhilu ngdy. Tir quan trie luyng mua X tinh duye tong luyng nudc lu cue dai khi mua Idn W„,ax:
Wmax=1000 a Xrnax-F
Tir dd ed t h i dy tinh duyc dinh IQ Idn tire thdi Qmax.tt, thdi gian tap trung nude Ep vd myc nudc lu H [6]:
Ep = (16,67.K.L)A/s= ^ 6,67.1./:, Vdi md khai thde g i n biln, c i n tinh tdi myc nudc biln dang, dinh trilu cudng, nguy ca sdng than.
Trudng hap khai thde ed nguy ea gap cde doi tuang chu'a nude ngim, eIn thdm dd xdc djnh cae d i i tuang chira nudc nay. Trdn mat d i t cd t h i tiln hanh do dja vdt ly dien tu' vd do vi tryng lyc. Cdc phuang phdp nay cd the plidt hidn cdc ddi chira nudc nam sau bang 1/3 chilu ddi tuyln
do vudng gde vdi via than.
Trong Id, trudc khi tiln guang c i n khao sdt dja ehin phan xa Khi phdt hiyn doi tuang ehira nude phia trudc guang, tiln hdnh khoan thdm do kilm tra vd thdo nude.
K i t luan
Cy ede md than him 16 viing Quang Ninh ed tilm an nguy ea bue nude. Dk phdng ngua ede md eIn tudn thu nghidm ngdt quy trinh, quy pham vd khdng chay theo san luang, to chirc thye hidn eong tde quan trdc dja c l t thuy vdn, koan thdm dd tiln trudc, khoan thdo khd nude vd mpt s l giai phdp khde./.
Tai ligu tham khao
[1]- Dieu kipn hinh thanh va anh hudng cua ddng chay tdi khai thac than ham Id vung Quang Ninh, 2000. Nguyen Van Chi (thu vipn Quoc Gia).
[2]- Quy hoach phan vung dja chit thuy van theo nguy ca buc nudc dam bao khai thac an toan cac md than ham Id Quang Ninh, 2007. Phung Mpnh Dac, Nguyen Van Chi va nnk).
[3]- Buc nudc ngpp Id khi khai thac than trong dieu kipn phuc tpp. Nguyen Van Chi
(tuyen tap Hpi nghj KHKT md quoc te. Ha Long-2010).
[4]- Du bao nguy ca buc nudc, ngpp md tu lu sdng suoi, 2004. Ha Thj Xuyen, Nguyen Van Chi (tuyen tap hpi nghj KHKT md toan quoc 2004).
[SJ-Bopbda c enesanHbrn npophieahA eodbi e eopHbie ebipadomKu. KanMbiKoe E fl, MocKea-Hedpa, 1973 aoda (Thu vien khoa hpc ky thuat Trung uang).
