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KHOA HOC VA C O N G N G H E MO^ NGHIEN COU LUA CHON CAC GIAI PHAP DAO CHONG LO TIET DIEN LCiij B A N G CAC PHIfONG PHAP DAC BIET
(Dun VUNG Din CHnr P H I / C i n p
' • ^ hyc t l , cdc cdng trinh nglm glao thdng, I thuy dipn thudng cd tilt dipn Idn, cdn trong hdm Id, cae him, tram, ga trdnh cung ed tilt dien tuong ddi Idn.
Trong md hdm Id, tilt dipn cdc dudng Id khai thdng, chudn bj phg thupe chu yeu vdo san lugng khai thac, kich thude thilt bj md cdn thdng qua vd luu lugng gid cdn thilt. Theo dipn tich tilt dien ngudi ta phdn ra cdc logi dudng Id cd lilt dipn nhd (dien tich d i n 12 m^), trung binh (12-^18 m^) va loai cd tilt dien Idn (trdn 18 m^).
Viec thi cdng eae dudng Id tilt dien Idn rdt khd khan, nhdt la khi dao qua vung dja chdt phuc tap, nhu phay pha kiln tgo, ddt da nut ne, ngdm nude,... [1].
Thdi gian tdi, trong ITnh vuc khai thdc than, khodng san se ed nhilu md hdm Id hipn dgi, nhu Nui Beo, Khe Cham ll-IV, vdi khdi lupng rdt Idn dudng Id khai thdng, chudn bj edn thi cdng, trong do nhilu dudng Id ed tilt dien Idn, phdn bd d muc sdu, trong vung ddt dd kdm dn djnh va ngam nudc. Trong dilu kidn nhu vdy, khi thi cdng dao, chdng Id, nhdt Id cac dudng Id tilt dien ldn, ngodi cdc giai phap ky thugt, cdng nghe dgc biet trong ddo, chdng Id, cdn phai ed nhung giai phap ky thugt bd sung d l xu ly ddt dd trudc, trong va sau khi dao Id [2].
1. Cac giai phdp XLP ly ddt da trong d i l u kien dja chdt phi>c tap
Sau khi Id dao vao da nguyen khdi, trgng thdi can bdng ty nhien eua khdi dd bj phd vd, khdi da bien dang va dich chuyin vdo dudng Id d l xde lap mdt trang thai cdn bdng mdi va tao dp lye len khung chlng. Mue dp biln dgng, djeh chuyin phu thuoc vao tinh chdt ca ly cua ddt dd, dilu kien dja chdt thuy van, kieh thudc, hinh dgng dudng id, chilu sdu bd tri cdng trinh vd
CONG NGHIEP MO s d 5 - 2 0 1 2
KS. NONG VI§T HUNG VA NNK Vi$n Khoa hpe Cdng ngh$ Md-Vinacomin phuang phdp thi cdng. So vdi eae khu vyc da\
dd dn d|nh, tgi cdc khu vye ed dilu kidn dja chit phdc tgp qud trinh djch chuyin vd biln dgng c6 diln biln nhanh han vd cudng dd ldn han nhilu. Vide dp dgng cdc giai phdp xu ly dIt da nhdm giam bdt muc dp khd khdn, tgo m6i trudng thi cdng thuan lgi han. Cac giai phdpxi)' ly ndng eao mue dp dn djnh cua ddt dd thuong dp dgng, bao gdm:
1.1. Giai phap ha mwe nwcyc ngam [3]
Trong trudng hgp dudng Id d khu vyc ngap nude, khi dd phai dp dung bipn phdp thoat nifdc, ha myc nude ngdm trudc khi thi cdng. D6i vai nhung dudng Id gdn mat ddt, cd t h l thoat nuac true tilp bdng cdc gieng khoan. bam nude len mat ddt, ddi vdi cdc dudng Id a dudi sau cung co tfil dupe thodt nudc bdng cdc gilng khoan, hoac thoat nudc xudng cdc tang dudi.
Qk thoat nudc tryc tilp ngudi ta thilt lap mot mgng Id khoan tu mdt dat d i n day tdng chipa nudc, doc theo tuyln dudng Id dy kiln dao (H.I).
Khoang cdch giua cdc Id khoan, chilu sau 1§
khoan thdo khd dugc xdc djnh tuy thudc vdo chi§u cao myc nudc tTnh, hp sd thdm cua ddt da ya chilu sdu dudng Id cdn ddo. Nhiung thdng s6 can xdc djnh Id luu lugng cua mdy bam q, ban kinh anh hudng eua qud trinh bam R, thdi gian hoat dOng lien tyc cua mdy bam t, myc nudc cin h?
thap Z vd hp sd thdm cua tang chda nude k [4].
He so thdm k dugc xdc djnh theo bilu thi>c;
k=^.!!fiM, ^lu. (1) n zi-2?
Trong do: q - Lu'u luong hut nu'do thye t l ciia may bom dSt trong lo khoan thi nghidm, m^/h;xi, X2 - Khoang cSch tir tSm 16 khoan toi 2 fliera quan sat (nlm trong ban kinh anh huong) code cao mi^c nuoc tu'ong u'ng Z, v^ Z2.
KHOA HOC VA C O N G N G H E MO
J ^ ^
Oi^ fi khoan than nifftr
10nfiii^p ^i^^f, WVilngdgtdachiJ'anuec XiyiLfcnydchathap DiTdng 16 dang d^o
h^^^'i
H. 1. Sa do bo tri 16 khoan thoat nuac va cac thong so chinh cua Id khoan Bdn kinh anh hudng R thudng ndm trong
khoang [(100-^300).r] (r - Ban kinh cua lo khoan):
R=3000.(H-h).Vk,m. (2) Trong do: H - Chilu cao cua mye nude chua dugc
hg thdp, m; h - Chilu eao mue nudc dd ha thdp trong Id khoan, m; k - He sd thdm, m/s. Vdi c h i dp bam khdng thudng xuyen bdn kinh anh hudng duac xdc djnh nhu sau (theo Dupuit [5]):
R - L s J ^ , m (3) Trong dd. n - Dp rdng eua ddt dd; k - Hp sd thdm,
m/h; H - Dp eao myc nudc d dilm miit eua bdn kinh tae dung R, m; t - Thdi gian bam, h.
Ngodi ra, ban kinh anh hudng R cdn ed t h l dygc xac djnh tu cdc cdng thuc tinh luu lugng nudc chay vdo Id khoan nhu sau:
• Chi dp bom thudng xuyen:
Mdi quan he giua myc nude cdn ha thdp d day edng trinh Zn„ khoang cdch tu tdm Id khoan tdi ddy edng trinh x, luu lugng cdn bam cua Id khoan q vd myc nudc hg thdp trong Id khoan h nhu sau:
7 - h 2 ^ q
7t.k -.In- (6)
-Tt.k, H"
= 1,365.k.L
ln(R/r) ln(R/r) Chi dp bam khdng thudng xuyen:
2.H(H-h) q^T:.k.-
ln(R/r)
(4)
(5)
Can cu bieu thue (6) ta cd the xdc djnh dugc khoang each cdn thilt tu Id khoan tdi day md cung nhu khoang each can thilt giija cdc lo khoan.
Khi dudng Id d dudi sau, su dung eae Id khoan thdo nudc trudc guong {H.2), phuong phdp nay ciJng dugc su dung d l thao cac tui khi hay thao nudc trong cdc hang cdc ta, cdc thdng sd thuy vdn tinh todn tuang ty trong trudng hgp thao nudc tu tren mat Ngodi giai phdp tren, tgi Lien Xd (cu) cdn su dyng phuong phap ddng bang hoa khu vye chudn bi thi cdng.
1.2. Giai phap gia ew&ng ddt da
Nguyen tie ehung Id phai gia cudng ddt da bd rdi, tdch Id xung quanh dudng Id thdnh mdt mdi trudng eung vung nhdt dinh. Giai phap thdng dyng dd vd dang dupc dp dung trong dilu kien Viet Nam, dd la bam ep vua. Khi bam dp vija vao khdi ddt da bj nut ne, vd nhau se dinh kit ddt da bd rdi Igi vdi nhau, tao nen "Idp ddt da dupc gia eudng".
CfiNGNGHIEPffl6s05-2012
KHOA HOC V A C O N G NGHE MO
H.2. Sa dd b6 tri lo khoan thdo nudc trong dudng him
phai dun n d n g c h a y b i t u m , chi dp d y n g khi khe nCrt a. Cac phwong phap gia cwdng dat dd
C d n h i l u p h u a n g phdp b a m dp v u a t h u d n g dp dyng, dd Id xi mdng hod, sdt hda, bi tum hod vd b o m ep v u a hod hgc.
• P h u a n g phdp xi mdng hod
D u d i dp Iyc b a m , dung djch v&a xi mdng d u g c dp vdo cdc khe n u t hay ede Id rong cua ddt d d , theo c h i l u sau phan bd eua Id khoan, ddng c u n g lai tao thdnh mdi lien k i t v u a xi mang v d i thdnh cdc khe nut. Tuy nhien p h u a n g phdp ndy ed n h u g c d i l m Id trong qud trinh ddng c u n g , vira xi mang bj eo ngdt t h l tich theo t h d i gian, Idm giam m u c do ldp day khe nut. Id rdng trong khdi d d . P h u a n g phap nay khdng phu h g p khi n u d c md mang tinh a xit cd hai v d i xi mdng, khdng t h l dp dung eho cae logi ddt dd ed he sd tham n h d h a n 1 cm/s, hogc cae khe nut ed c h i l u rdng nhd b a n 0,1mm, hodc cac khu v y c n u d e cd dp.
•> P h u a n g phdp set hod
P h u a n g phap nay ed tdc d y n g t u a n g t y n h u p h u a n g phap b a m dp v u a xi mdng n h u n g hidu qua thdp han Theo p h u a n g phdp ndy, thay bdng vi>a_xi mdng, n g u d i ta s u dgng dung dich sdt ldm t u hdn hpp set vdi ham l u g n g cdt n h d h a n 5 %. D^
tang tdc dp ldng cua dung dich sdt, cd t h l eho them vdo dung dich mdt sd chat dipn phdn n h u Clorua Canxi (CaCl2) hoae thuy tinh long (Na2Si03), vdi hdm l u g n g hgn c h i . S o v d i xi m d n g , set cd dp nhdt cao h a n , vi vdy d l lap day khe n u t vd lo rong ddt dd, cdn phai b a m dung dich sdt v d i dp Iyc cao hon
• P h u a n g phap bitum hod
Khac vdi cdc p h u a n g phdp trdn, mdi lien hp giua b i t u m v a thdnh khe n u t tao nen chi bdng l y e ma sat, D l ldp cdc khe n u t v a khoang trdng eua ddt da bdng Bitum, phai b a m dung djeh Bitum ndng chay vdo khdi da can gia c u d n g , ddy n u d c trong khdi ddt dd ra ngodi, sau d d bitum ngugi di v d ddng lgi P h u a n g phdp nay t u a n g ddi p h u e tgp, do
CONG NGHIEP mo sd 5 - 2 0 1 2
trong khdi dd I d n h a n 0,2-^1 m m v d luu lugng lan h a n 6 0 m^/ng.d.
•:• P h u a n g phdp h o d hpe
Trong p h u a n g p h d p nay, thay bdng xi mang, s6(
hay Bitum, n g u d i ta s u d y n g hda chdt thudng la PolyUrethane (Pus). D u n g djeh hod chdt diipc b a m dp s u i t c a o v d o khdi ddt d d , theo thdi gian ede phan u n g h o d hpe xay ra. xudt hien hien tii^ng t r u a n g n d sui bpt d l tdng t h l tich chen ldp cacl6 rdng ( t h l tieh v u a t d n g len 3 0 ldn), gdn k i t cdc thdnh phdn thgch hgc v a c d hieu qua ngan nuac tdt, tgo len I d p d d gia c u d n g c d dp b i n cao, eo ktia ndng chiu I y c n h u mgt d g n g vo chdng mdi. Dung dich hod chdt c d the Id mdt thdnh phdn hoac nhi§u thanh phdn rieng biet, d d t h d m thdu cua vi>a difac dieu k h i l n k h o n g n h u n g b d i d p sudt b a m ma con bdi d d deo cua s a n p h d m ,
b. Tinh toan xdc djnh cdc thdng so eua c6ng nghe bom dp vwa [4]
Cac t h a m sd c h i n h c u a c d n g nghe b a m ep vOa, bao g d m bdn kinh gia c u d n g (R), khoang cacti hdng Id k h o a n t h e o tryc d u d n g Id (a), c h i l u day ldp gia c u d n g (c), sd lo k h o a n tren g u a n g gia cu'O'ng (No), khdi l y g n g v y a b a m ep cho mgt l5 khoan (Q,), khdi l u g n g v d a cho 1 vdng (Q), dp Iyc pM vita vd c h i l u day t u d n g ehdn phan dp.
• Ban kinh gia c u d n g (R):
Bdn kinh gia e u d n g tinh todn:
- 1 5 ^ J K ' H r i . ( H i / U 2 ) .
' V Pn • (7)
Trong d o ; f i , va H2 - B o n h M cua n u d c va cua via gia c u o n g ; k - He s6 t h l m cua Sk Sa vCing gia eft' - T h o i gian c h u y i n dOng cua vCra trong 6k da tree khoang c4ch R; H - A p l u c nu'do thuy tTnh; ri - Ban kinh IS k h o a n ; n - H $ s 6 d5 rSng viing dSt da can gia c 6 ; p - H? s 6 ke den m u c do nhai dSy cua via.
•:• K h o a n g each giOa cac hang 16 khoan theo
KHOA HOC VA C A N G NGHE MO
jjUlB
trgc dudng td (a), dugc xdc djnh theo edng thi>c:
a=(2R/sina), m. _ (8) Trong do: a - Gdc tgo bdi gdc nghieng Id khoan vdi tnjc dudng Id; dd.
• Chilu ddy Idp gia cudng (c), dugc xdc 6\nh theo cdng thuc thye nghipm:
C=(b.m), m. (9) Trong dd: B - Chilu rOng dudng Id, m; m - H^ sd
thye nghipm.
• sd lo khoan tren guang gia cudng (No), ddi vdi guong Id tilt dipn trdn:
"•(D^O-5-C)... (lOj
Nn -:id.
Trong dd: D - Dudng kinh vdnh dai Idn nhit xung quanh dudng Id dugc gia cd, m; C - Chilu ddy vung gia cd xung quanh dudng Id, m; R - Bdn kinh gia cd nhd nhat, m.
•> Khdi lugng vua bam dp cho mdt Id khoan (Qi):
Qi-mh.7r.Ro.L, m^._ (11j Trong do: R- Bdn kinh thdm thdu cua vda; m; L- Chieu
ddi phdn Id ep vua; m; mh - Hd sd lo rdng hdu Ich;
mh=0.134.Qn.tn/Lth-d?p.%- , (12) Vdi: Qn - Khdi lugng nudc cho mpt lo khoan, m Is;
tn - Thdi gian bam nude cho mdt Id khoan, s; Lth - Chilu ddi thdm thdu cua mpt Id khoan, m; dep - Bdn kinh phdn bd nude trung binh, mh=0,14.
•:• Khdi luang vOa eho 1 vdng:
Q=(n.Qi). (13) Trong dd: n - Sd lo khoan tren vdng.
• Ap luc phut vua
Ap Iyc phyt vua cho phep ed quan hd din nhilu ylu td nhu chilu sdu Id khoan, tinh chdt eua nham thach, cua vung ddt da, chilu rdng va chilu sdu khe nut, dd sut eua vua,.... Trong trudng hgp cd nhilu nude ngdm, dp Iyc phyt vOa phg thude vdo dp luc nudc, binh thudng dp Iyc gdp 2-^3 ldn dp sudt thuy tinh. Thye t l ehua cd phuang phdp tinh todn chinh xdc nen thudng phai xdc dinh qua thi nghiem, tuy vdy, trong tinh todn sa bd dp tyc bom dp cho mpt lo khoan cd t h l theo cdng thue:
R ^ V R / O f ^ k G W . (14) 0,367.K.t
Trong dd: R - Bdn kinh phdn bd dung djch trong khdi ddt dd, m; (ph - Dp rong hO'u ich eua ddt dd, %;
Y - Trpng lugng t h l tieh cua dung djch, T/m^; rp - Bdn kinh Id khoan, m; K - He sd thdm thdu, m/ngdy-dem; t - Thdi gian bam dung djeh, phut.
• Chilu day tudng ehdn
Dd ndng eao hieu qua bam dp vu-a, phai ed tudng ehdn phan dp, vdi dp day phg thugc vdo dp Iyc bam, theo kinh nghiem cd t h l ehpn thdng sd ndy trong Bang 1.
2. Cac giai phap thi cong dao, chdng 16 t i l t dien Idn
Hai cdng dogn chinh trong thi cdng ddo, chdng Id anh hudng tryc tilp d i n di^ dn djnh cua dudng Id, dd Id ddo vd chdng giCr. tu dd hinh thdnh nhdm cdc giai phdp thi cdng tuang ung vdi ti>ng cdng dogn eg t h l .
Bdng 1.
Ap Iyc bom vOa, kG/cm^
>5
>10 20+30
>30
Chl^u dSy tu'ong chan, m 1,0 1.2 1.5 2.0 2.1. Cdc giai phdp dao Id
Be dao id, cd t h l dp dyng sa dd ddo todn guang; ddo vdm tiln trudc rdi hg ndn; nde tiln trude rdi md rpng sang hai ben vd hg nin nhidu ldn; ddo Id dan hai ben, nde tiln trudc, vdm ngygc vd md dudng hdm dan, khai ddo tdng phdn. D I dam bao dp dn djnh cua dudng Id vd tang tde dp thi edng cd t h l dp dung mpt sd giai phdp ddo Id, nhu sau:
• Kit cdu chdng tao d vdm vugt trudc, k i t cdu chdng trudc. Vipc su dung cdc kit cdu chdng tiln trude hoae euge ehdn nhdm chdng gid ddt dd phia trudc guang ddo d phia nde dam bao cho cdng viec hogt ddng khai dao ben dudi d vdm vupt trudc mdt cdch an todn.
• Chia nhd guang dao Id: ddi vdi cae guang Id tilt dien ldn, nhdt la trong_trudng hap_ dat dd lien kit y l u , nhdm giam thilu lugng ddt dd d guang hdm trdi vdo ben trong dudng hdm, ngudi ta thudng dp dyng giai phdp ehia nhd guang hdm d l thi edng. Giai phdp ndy phdt huy hipu qua ngay ea khi dao cdc dudng Id tilt dien Idn trong ddt dd cung d i n rat eung, khi dd viec chia nhd guang se tgo thugn Igi cho edng tdc ddo Id, do tgo ttiem_ nhieu mat thoang cho nd min vd Idm suy y l u k i t cau cua khdi dd.
2.2 Cdc giai phdp chong giir [5]
Mdt sd logi k i t eau chdng thudng dp dyng trong dilu kien dja chdt phuc tgp, bao gdm k i t cdu Id tilt dipn trdn. Id hinh vdm tudng dung vd Id hinh mdng ngya, cd dam n i n .
• Dgng k i t cdu tilt dien hinh trdn la logi k i t cdu chju iyc tdi uu nhdt khi dao trong eae mdi trudng cd dp lye tuang ddi d i u tu mgi hudng.
• Dang kit cdu_ Id hinh vdm tudng dung, cd ddm nin kit hgp dd be tdng luu vi de thi edng va cd kha nang chiu lye trong mdi trudng dp Iyc nde vd nin Idn, dp Iyc hdng nhd, phu hgp dp dyng cho cdc dudng Id dao qua sdt kit ho^c ddt da cd tinh truang nd, bDng nin.
CONG NGHIEP MO SO 5 - 2 0 1 2
I322|_
KHOAHQCVAcONGNGHiMO•:• Dgng kit clu Id hinh mdng ngya, c6 dim nin kit hgp uu dilm cua dgng Id hinh trdn vd kh^e phgc ddng k l hgn ehi cua Id hinh vdm tudng dung. Chinh vi v^y dgng kit clu ndy dugc dp dyng rdng rdi khi ddo Id qua vung ddt dd ylu (bai thai, phay, phd....), tuy nhidn gia cdng vi chdng vd thi cdng phdc tgp han so vdi cdc kit elu khde.
3. K i t lugn
Theo k l hogch phdt triln san lugng, thdi gian tdi nhilu md than hdm Id vCing Quang Ninh se ngdy cdng phai khai thdc xudng sdu, dilu kl^n khai thdc ngdy cdng khd khdn vd se phai thi cdng mdt khdi lugng Idn cdc dudng Id tilt di$n Idn, trong dilu kien dja chit phuc tgp. D^ ndng eao chit lugng, hi$u qua cua cdng trinh, dam bao an todn trong thl edng ede dudng Id ndy, cdn thilt phai dp dyng cdc giai phdp ky thudt, cdng nghp ddc bidt, kit hgp dp dyng ca hai nhdm giai phdp, bao gdm cdc giai phdp xu ly dat dd, thdo khd, gia cudng ddt da ylu nhlm eai thipn dilu kien thi cdng vd cdc giai phap thi cdng hgp ly trong khdu tdch phd gyang vd su dung cdc kit cdu chdng giu hgp ly •
TAI LIEU THAM KHAO
1. Quy hoach phdt triln nganh than giai doan 2010-2015. tdm nhin din 2025.
2. Dy an ddu tu khai thac hdm Id md Khe Chdm ll-IV. Vien KHCN Md-Vinacomin.
3. Dy an ddu tu khai thde hdm Id md Nui Beo, Vien KIHCN Md-Vinacomin.
4. Thodt nude md Id thien. NXB Giao thdng Vgn lai. Ha Npi. 1992.
5. Phgm Minh Due. Bao cao tdng kit d l tdi nghien cuu dp dyng thu nghiem phuang phdp gia eudng tgi cdc md hdm Id. 2005.
6 Nguyin Quang Phich. Bdi giang ca hpe dd.
Tru'dng Dal hoc Md-Dja chdt.
7. Tinh todn thilt k l cdng trinh ngdm. Nhd xudt ban Xay dyng
8, Bdi giang cdc phuang phap ddo va xu ly mdt dn dinh cdng trinh su dyng phuang phap bom dp vi>a xung quanh cdng trinh ngdm ndm 2006.
Ngwdi bien tap: Vd Trpng Hung
The paper introduces the method choosing the especial driving and supporting method for the big cross section tunnel in the rock mass with complicated conditions.
NGHIEN CUU KHA NANG...
(Tigp theo trang 26) thdng VJn tai. H4 NOI. 1999.
2. NguySn Boi. TuySn noi. Nha xuat ban Gia{
thdng V$n tai. HS NOI. 1998.
3. Ta Qu6c HCing, Nguyen Thu Thuy, Pharr Thj Hai Dang. Nghidn cuu th^nh phin v|t chii qu$ng feldspar mo Lap Thach-VTnh Phuc nhlm djnh huting cdng ngh$ ch4 bl4n. Bao cao Hpi thao Khoa hoc vS Cdng ngh§ Phuc vg phat triln KTXH Khu vu'C TSy Blc. Vi#n Khoa hoc & Cong ngh0 Vi^t Nam - Ban Chi dao Tay Blc - Uy Ban Nhan dan tinh YSn BA\. 2012.
Ngwdi bien i$p: Tran Van Tr^ch
1. Dao tri noflo khong lo khong co phep trj, chi lo khong chon dirac ngUdi hien. Bing Huy Trir.
2. Khong cl dau ngi/cIi ta c6 the sung sudng han bSng trong gia dinh cila chinh minh. J.
F. Marmontei.
3. NhiJng bSi hoc tha'm thi'a nhat dau phai do thSnh c6ng mS c6, m& chijng c6 dudc chinh la nhd d siJ gian truan, A. B. Alcott.
4. Khdng o6 gi cao thirong va dang kinh blng I6ng chung thu^. Cicero.
5. Tr^ khdng ging sCrc, gi^ nhufng ngam ngiji. CSthi Trung QuSc.
6. Con ve cSi kiSn III t i m gifong ve sif lo xa va c i n trpng, Ng^n ngCT Phuang Ddng.
7. Ngubi ban tfit nhit bao gid cung la ngKcli ban d i n vdi ta trong nhCfng phijt khd khan, cay ding nhit cila cudc ddi. M. Gorki.
V VTHstnitAn^
C(lNGNGHI|PM6sttS-2012
