KHfio sfnrOldcHm*CONG TRINH, o\fi wffv THOY V^N

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Thong tin khoa hoc cong nghe m o

KHfio sfnr Old cHm* CONG TRINH, o\fi wffv THOY V^N phuc v u thi^'t ke, thi coug gieug dufug

So far, some twin vertical shafts have been constructed in Quang Ninh coal basin for serving the purposes of increasing coal output by lowering the mining depths.

Therefore, experience in surveying, designing, constructing and supervising works for the vertical shaft construction have been limited. The paper refers to some problems related to the survey works for the hydro-geological and engineering geotechnical conditions for designing and constructing vertical shafts

Ths. VU CHAU TUAN KS. D 6 KIEN CUONG

Vien Khoa hgc Cong nghe Mo - Vinacomin

Trong Ijch s u thi cdng xay dyng va khai thac md ham Id d Viet Nam da ed r i t nhilu hang mue edng trinh phye vy cho cdng tac khai md nhu mat bing san edng nghiep, cac hp thong Id bang xuyen via, dpc via, eae Id gilng nghieng...

Tuy nhien, edng tac thi edng xay dyng gilng dipng cdn cd nhilu ban e h l . Hien nay, trong Tap doan Cdng nghiep Than -Khoang san Viet Nam (Vinacomin) chi ed cap gilng dipng d Cdng ty Co phan than Mong Dyong va gan day nhit la cap gilng dipng tai Cdng ty Co phin than Ha Lam. Cdng tac thi cdng xay dung cac gilng dipng nay d i u do cac chuyen gia Lien Xd va Trung Quoc giup 6a. Chinh vi vay ma g nude ta nhu'ng kinh nghiem ve khao sat, quy hoach thilt k l , thi cdng cung nhu giam sat thi cdng trong ITnh vuc xay dyng gieng dipng edn cd nhilu han che.

Trong sy phat triln chung cua cac hoat dpng kinh te - xa hpi eua d i t nude ndi chung va eua nganh than ndi rieng, khi trO lugng than t i n g Id bang ngay d i n can kipt, viec thilt k l khai thdng khai thae phan tru' lugng nam dudi sau bang

cac gilng dipng la xu the t i t y l u . Trong tuong lai g i n , md h i m Id Nui Beo va md than Khe Cham II - IV se dugc d i u t u xay dyng, khai thdng bang eae gilng dipng vdi chilu sau

«600m tinh tip mat dit. Chinh vi vay, chiing ta c i n thilt phai quan tam d i n nhu'ng v i n d l dac thil chuyen sau lien quan d i n cdng tac xay dyng gilng dipng, trong dd cd v i n d l khao sat dja chit cdng trinh (DCCT), dja chit thuy van (DCW) d l xac lap cac giai phap diing d i n v l ky thuat va hgp ly nhit v l kinh t l khi thilt k l , thi cdng xay dyng gilng dipng.

I.' NhiVng v i n d l chuyen mon khi khao sat DCCT cho xay difng gilng du'ng.

1. Quy hoach vj tri gieng.

O Viet Nam ton tai hai dang mdi trudng d i t da khac nhau: mdi trudng da CLPng va mdi trudng da mem rdi. Khi quy hoach chpn vj tri xay dung gilng dipng d hai dang mdi trudng d i t da khac nhau, can luu y nhu'ng v i n d l chuyen mdn sau:

- 6" khu vuc mdi trudng d i t da cd e l u tao dja chit tot, Cpng s u i t dja tTnh khdng Idn, dja

t i n g gom cac Idp d i t da cd chilu day Idn va da cd cudng do cao thi gilng dipng ed t h i dugc thilt k l khdng cd k i t c i u khung vd bao ve giu' dn djnh hoac chi thilt k l k i t e l u nhe. Trudng hgp e l u tao dja c h i t kem, ed nhilu dipt gay di qua, nhilu he thong khe nipt va ddi v g vyn, ipng suit dja tTnh r i t Idn, da t r i m tich vdi cac Idp da ed chilu day nhd, da bj phong hda, chipa nhilu nude... thi k i t e l u khung vd chong cua gilng se ehju ap luc cCia d i t da vay quanh r i t Idn, anh hudng d i n s u sap Id, m i t on djnh hoan toan cua khung vd chong.

- Trong mdi trudng da khd hoac It chLPa nude, khi thilt k l khung vd chong gilng c i n thiet phai thilt k l thoat nude ca trong l i n ngoai, do dd, khdng can xet d i n v i n d l ap lye thuy tTnh do nude nglm gay ra. Tuy nhien, khi chpn vj tri xay dyng gilng thudng phai tranh nhung khoi da cd nhilu khe nCpt d l phdng tranh nude t h I m vao edng trinh khi cd mua bao, thdi t i l t b i t thudng eua thien nhien. Doi vdi mdi trudng da cd nude ngam phong phii, khi thilt k l thi edng gilng b i t budc phai

KHCNM s o 4/2011* CNKT HAM LO

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dac biet chii y din thilt k l chong thIm ben trong gilng, ddng thdi phai xet din tac dyng eua ap luc nude tip ben ngoai.

- 6" khu vuc mdi trudng dit da mIm rdi, khi thilt k l va thi cdng xay dung gilng thi cd hai vin d l v l dja chit cdng trinh cin phai dac biet chii y.

Dd la cudng dp ehju lye cua dit va mipc dp phong phii cua nude nglm. Nhit thilt phai chpn dja dilm xay dyng cd cac Idp dit day va cd kha nang ehju luc cao, khdng ed nude ngam hoac nude nglm khong phong phu, tranh nhCpng viing cd dit biin ylu, cat chay, dit lun udt, nhilu nude nglm.

2. Khao sat DCCT.

Khi khao sat DCCT cho xay dyng gilng dipng can dac biet quan tam din dja mao, tipc la nghien CLPU cac dac trung hinh thai cua dja hinh va qua trinh ddng luc lam biln ddi dia hinh. Cac dac trung dja mao se chi phoi viec quy hoach chpn vj tri mat bang md cipa gilng, cao do mat bang, tilt dien va chilu dai cua gilng. Trong mdi trudng dit da, vj tri eu'a gilng thudng dugc chpn ngi dja tang ed Idp da day va cudng dp ehju lye cao, do doc dja hinh nhd ban 45°, tranh chpn nhCpng noi ed vach da cao d l sat Id, cd hien tugng trugt, da do, lu da.

3. Dieu kien dia chat Dilu kien dja chit la mdt trong nhu'ng yeu to chu ylu anh hudng din sy on djnh eua cdng trinh. Quy hoach chpn dja diem, thilt k l va thi cdng xay dung gilng dipng

phai dua tren ca sd danh gia djnh tinh sy on djnh cua cdng trinh. Trong qua trinh khao sat DCCT dilu quan trpng chu ylu la phai dy bao danh gia sy on dinh cua dit da vay quanh gilng dipng sau khi da xay dyng xong nham myc dich cung d p dip lieu diu vao cho thilt k l va thi cdng gilng.

Cd hai ylu to chu ylu anh hudng din su dn dinh cua cdng trinh: ylu to dja chit va ylu td xay dung, bao gdm ca cdng tac thilt k l va thi cdng.

Ddi vdi ylu to dia chit cin chu y din dac trung kit elu cua t h i da nguyen trang, cudng dp ehju lye cua da nguyen trang va hoat dpng eua nude nglm.

gilng trong nIn dit cd the xult hien ap lye thuy ddng, tip dd gay ra cac hien tugng cat chay xdi nglm, ddng thdi nude ngam thIm vao khdng gian cua cdng trinh gay khd khan cho cdng tac thi cdng va nhCpng hoat ddng sau nay cua gilng.

4. Trang thai img suat ban dau cua moi tru<yng dat da.

Nlu mot lin xay ra van ddng dja chit thi se tao nen LPng suit kiln tao xult hien ben trong dja ting, v l sau chung cd t h i biln ddi va giai thoat gay nen cac hien tugng dja chit trong edng trinh, tao nen nhCpng biln dang dj thudng, gay mit on djnh va Phan cap do cirng cua da (dtra theo gia tn cwang do khang nen don true d trang thai bao hda)

F (MPa)

Dp CLPng cua da

>120 120 ^ 70 70H-30 Da cuTig Ra'f

cCrng Cimg Tuong ddi cCrng

30H-15 15H-5 <5 Da mIm Tuang

ddi mim Mim Rit mim Cudng do cua t h i da

nguyen trang dugc danh gia tren co sd dya vao cudng dp khang nen d trang thai bao hda cua da kit hgp vdi danh gia mipc do nguyen khdi eua nd.

Tac ddng eua nude nglm doi vdi do dn djnh cua cdng trinh la gay ra ap luc thuy tTnh tac dyng, len eae kit elu khung vd chong cua gilng lam giam cudng dp ehju lye cua dit da vay quanh, gay ra biln dang va mit on djnh, gay ra cac hien tugng anh hudng din su on djnh eua edng trinh:

hipn tugng phong hda phat triln, hien tugng an mdn hda hpc tao nen hang ddng trong dit da vay quanh, cdng trinh

cd t h i lam hu hdng cdng trinh. Vi vay, trang thai ipng suit ban diu cua mdi trudng dit da la mdt trong nhCVng ylu to can phai xet din khi khao sat thilt k l va thi cdng xay dyng cdng trinh. Trang thai LPng suit ban diu gom cd ipng suit dja tTnh va ipng suit kiln tao, chiing hien dien trong mdi trudng dit da ty nhien trudc khi edng trinh dugc khdi cdng. IJng suit dja tTnh la do trpng lugng ban than cua dit da tao nen, ipng suit kiln tao gay nen bdi lye kiln tao phat sinh tip cac van ddng dja chit ndi lye trong vd trai dit. Mdi trudng dit da sau khi da hinh thanh, trong suot qua trinh ton tai, ludn trai qua nhilu ki van

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ddng dia chit nhu van ddng nang ha mat dat, van dpng tao nui... IJng suit kiln tao theo phuang thing dipng va phuang nam ngang diu ed gia trj khac nhau, dong thdi tren mat phang nam ngang thudng xult hien ipng suit chinh Idn nhit va nhd nhit, gia trj cua chung khdng bang nhau.

11. Phu'O'ng phap va npi dung khao sat DCCT cho xay dyng gilng du'ng.

Trong thilt k l va thi edng xay dyng gilng dipng ed nhu'ng vin de chuyen mdn mang tinh dac thii rieng. Vi vay, ndi dung va yeu cau khao sat DCCT eCJng cd nhCpng myc dich va yeu elu rieng vdi cac phuang phap nhu do ve thyc dja, khoan, dao, tham dd dja vat ly, thi nghiem trong phdng va hien trudng, k l ca phuang phap quan trie hien trudng.

- Do ve thyc dja nghien CLPU cac b l mat kit elu, cac to hgp khe nipt, vj tri t h i nam cac dipt gay, kich thude va trang thai gin kit va mCpc dp chipa nude cua dipt gay, cua khe nipt, nghien CLPU eae dac trung dia mao va cac hien tugng dja chit ngoai sinh, hinh thai va sy on djnh eua dja hinh.

- Phugng phap khoan, dao kit hgp dja vat ly nghien CLPU

dac trung dja ting, sy phan bd cua dja ting va mdi trudng dit da, b l day cua ting phu va ddi phong hda, xac djnh quy luat eua cac dipt gay, cac to hgp khe nipt, cac Idp kep mim ylu va eae hang dpng.

- Phuang phap thi nghiem trong phdng nghien CLPU cac

tinh chit co-ly cua dit va da, nhipng tinh chit dac trung rieng nhu he so hda mem cua da, tinh chit an mdn tao hang ddng, tinh truang nd, tinh nen lun.

- Thi nghiem hien trudng nghien CLPU cac dac trung ca hpc eua t h i da nguyen trang va cua cac be mat kit elu, nghien CLPU pham vi phat triln cua ddi xao ddng trong da vay quanh va trang thai LPng suit ty nhien, cac dac tryng sdng dan hoi cua t h i da nguyen trang, nghien CLPU

dja nhiet va kha nang chipa khi chay va khi dde trong mdi trygng dit, da.

- Phugng phap quan trie theo ddi diln biln lau dai cua cac hien tugng biln dang va LPng suit trong dit da vay quanh, ap luc dit da va boat ddng eua nude ngam, sy xult hien cua khi chay va khi dpc.

Cac thong tin cin thilt phuc vu cho cong tac thilt k l va thi cong gilng:

- Xac djnh cac du' lieu v l dja ting va elu true kiln tao eua khoi da md (xac djnh chi tilt va chinh xac sy phan bo eua eae Idp nham thach dpc theo hanh trinh eua gieng nhu chilu sau, chilu day, gde cam, dp lien tyc, thanh phin vat chit va elu tao eua cac Idp dit da ylu va cac Idp dit da kep cd xu t h i bj ep trdi va biing nen, cac mat tilp xuc cua cac Idp cung nhu eae thiu kinh dit da ed dp lien kit ylu).

- Xac djnh chi tilt tinh chit ca ly cua cac Idp dit da dpc theo hanh trinh cua gilng nhu xac dinh tinh chit co ly cua

tipng doan theo chilu day va t h i nam, xac dinh chi tilt doi vdi t i t ca cac Idp dit da, cac Idp kep cd chilu day Idn hon 0,3m.

- Xac djnh eae dac dilm DCTV cua dja ting dpc theo hanh trinh eua gilng di qua (su phan bo chilu day cua cac ting ehCpa nude va each nude, ap lye thuy tTnh, thuy dpng, he sd thIm eua cac ting chLPa nude va moi quan he cua chung vdi cac ddng nude tren be mat dit va cac edng trinh chipa nude, cac dac tinh an mdn hda hpc eua nude). Dy tinh lugng nude chay vao gilng.

- Xac dinh dac diem dja chit, elu tao, chit lugng va chilu day eae via than ma Id khoan di qua

- Danh gia chit lugng khoi da theo RQD phye vy edng tac gia ed thanh gilng.

Ket qua cong tac nghien cCeu DCCT phai dat dwac :

Hinh 1 - Mau Idi khoan

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- Xac djnh gia tri trung binh cac chi tieu eg ly da cho tipng Idp dit da dpc theo hanh trinh eua Id khoan.

- Xay dung bang tong hgp gia trj trung binh tinh chit eg ly cho tipng loai da dpc theo hanh trinh cua lo khoan.

- Xac djnh ehi sd RQD theo cac doan miu eua tipng hiep khoan.

* Cac chi tieu eg ly da yeu cau thi nghiem:

- Cudng dp khang keo (ak);

cudng dp khang nen (an);

dung trong (y); ty trong (A); dp Im (Wkg); lye dinh kit (C);

gde ma sat trong (cp); Tinh toan he so kien eo (/).

* Cac thdng sd DCTV yeu cau xac djnh trong cdng tac bom hut nude thi nghiem: he s l thIm thIu K (m/ngd); luu lugng Q (l/s); he sd ty luu lugng q (l/sm); trj so ha thip mue nude S (m); phan tich thanh phan hoa hpc eua nude gom: anion (CI'; HCO3'; S04^';

COs^"); Cation (Ca""; Mg"";

Fe""; Fe"""; Na"; K"); tong dp CLPng: ma/I.; do cipng vTnh CLPU:

ma/I; dp cipng tam thdi: ma/I;

dp pH; tong dp kilm: ma/I;

lugng CO2 an mdn: ma/I;

Lugng CO2 ty do: ma/I; Can saukhislyg160°C: ma/I.

* Yeu elu phan tich mlu khi dinh luong gom: CO2, CH4, 62, N2, H2, CO

* Doi vdi cac miu liy tip via than, eae chi tieu yeu elu phan tich: Dp tro than Ak (%);

Dp Im phan tich Wpt (%);

Nhiet luong chay Qeh (Kcai/kg ); Chit boc Vch (%);

Ham lugng luu huynh trong

Hinh 2 - Thi cdng khoan khao sat DCCT- DCTV tai md Nui Beo

than (%); Khoi lugng rieng than (dk g/em^);

Doi vdi cac mlu liy tip da kep va sat vach, sat try via than vdi myc tieu chu yeu la xac djnh ham lugng chipa than trong da, nen chi eIn phan tich dp tro cua m i u Ak (%) va khoi lugng rieng than (dk g/em^).

Tdm lai, trong cdng tac thi cdng xay dyng cdng trinh nglm ndi chung va gilng dipng ndi rieng ed rit nhilu vin d l phLPC tap nhy; dp on djnh cua dit da vay quanh, cac hien tugng eg hpc va dja chit dj thudng, ap lye dit da biln dpng, LPng suit dja tTnh

Mdi trudng dja chit va moi trudng dit da thudng khdng ddng nhit va khdng dang hudng, khi ehju tac ddng cua ylu td khach quan thi se biln doi va t h i hien thdng qua eae hien tugng mit on djnh. Kit qua khao sat chi dya tren nhu'ng du' lieu han ehl d l dua ra nhCpng danh gia dy bao. Vi vay, mCpc dp chic chan cua nhCpng dy bao dd la ed ban, cin phai dugc kilm chipng bang nhCpng tham dd dy bao trudc thi edng. Ngoai viec phai tiin hanh khao sat DCCT- DCTV d l phye vy thi edng la dilu phai lam, doi vdi bit thudng, thao khd va cdng tac xay dyng gilng dirng chong thIm phipc tap, anh cin phai tiin hanh khao sat hygng cua khi chay va khi

dpc... Vi vay, edng tac quy hoach, thilt k l thi cdng xay dung ddi hdi phai chat che, chit lugng cao; kem theo dd cdng tac khao sat DCCT, DCTV phai dugc nghien CLPU

mpt each chi tilt.

trudc thi edng nham kiem chipng nhCi-ng danh gia dy bao dyge neu ra trong khao sat g giai doan trydc, dong thdi, edn dy bao nhCpng vin de cd the phai doi mat trong khi thi edng./.