Thong tin khoa hgc cong nghg m o
^%a hinh thanh, phan bo dng suat VA MOI LIEN HE GlffA llING SUAT VtTl KET CAU VO CHONG
KHI THI CONG GIENG DUlNG TRONG VUNG QUANG NINH
For meeting the coal demands to the national economy, in the coming time, the coal sector needs to carry out the coal mining operations at the deeper mining depth for Increasing the coal output, therefore, a series of new mines with vertical shafts have been developed. Due to the topographic features and mine structures, most of vertical shafts have to be constructed in the complicated hydrogeologlcal and engineering geotechnical conditions, causing the non-uniform force distribution, therefore, the structure of the steel and the reinforced concrete linings should meet the long time load- carrying ability The paper refers to the stress distribution and formation and the relationship between the stress and the structure of the reinforced concrete linings when constructing the vertical shafts at Quang Ninh coal area
TS. PHAM MINH OUC
Viin khoa hoc COng nghd Md- Vinacomin Bien t$p: TS. Trvomg Dufc Dif
1. Md'ddu
Trong md ham Id md via bang gieng dung, thdi gian ton tgi cua gieng dOng bdng tu6i md, do dd, ket cau ehong gieng dung phai dam bao on djnh trong suot qua trinh van hdnh md.
Tuy nhien, cde gieng dung xdy dyng a nudc ta thi ket edu vd ehong gieng cdn phai ehju tdc ddng eua nudc an mdn mang tinh axit, khi thanh phan hod hgc trong than viing Quang Ninh cd ham lup'ng luu huynh (S04) eao, khi hdu nong am Them vdo dd, gieng thudng dug-c xdy dyng trong d\hu kidn be mat dat phu Id dat dd rdi rac tren todn bd dogn mipng vd cd gieng, phan do mc cdng nghp, thdn gilng ddo qua eae Idp dd vd than cd chilu ddy vd gdc doc Idn.
D i l u kipn dja chat md vung Quang Ninh vdi nhu-ng dj biet nhu da neu Id nguyen nhdn gdy nen sy phdn bo ung suat vd hudng tdc dyng cua dp lye cung nhu dp Idn cua chung khdc nhau theo hudng phan bo, anh hudng den kha ndng 6n djnh Idu dai cua vd ehong, ddi hoi phdi cd sy quan tdm nghien cuu
2. S y hinh thdnh vung irng sudt tap trung, qua trinh phan bd irng sudt va tai trpng khi gidng di>ng ddo qua cac lap ddt da khac nhau
Dieu kien cau tgo Idp dat dd phu tren Idp da goc vung md Quang Ninh dug-e md ta khd day du trong cdc du an xay dyng cdng trinh khai thdc than xuong sau tgi cdc md ham Id md vfa bang gieng dung trong vung Quang Ninh, nhu md than Ha lam, Niii Beo, Khe Chdm ll-IV, Mao Khe...Trong thiet ke xdy dung gilng dung tai eae md ndi tren eho thdy, nhieu gieng md ed phan mieng vd eo gilng phai bo tri d cdc ldp dd thai, vdi ehieu ddy vdi met den vdi chuc met.
Thi edng mieng, co gieng trong vung dat da b6i tieh, md hinh tinh dug'c nhilu tdc gia lua chpn [1], [2], [5] Id mdi trudng dat da rdi rge. Khi dat dd chua ddng kit hoae ddng k i t chua sau, cdc hat dat da dup'c dua vao md hinh tinh cd tinh rdi rge cao. Trong khi dd, khi edng trinh xdy dung trong tang dd goc md hinh dat da dug'c xay dyng cd dang cdc khdi, Idp.
Khi xay dung mieng, co va thdn gilng trong ddt dd vd khoi dd, xung quanh thanh gieng xudt hien vur ^ ung suat tap trung. Cdc gilng dung da vd dang dup'c xay dung c nudc ta ed tilt dien hinh trdn. Khi ddt dd vd khoi da bj pha vd, xung quanh thdnh gieng dat dd bi nut ne. Chilu sau vung nut ne Idn hay nhd phy thude vao edu tao eua dat da nguyen trang va phy thude vdo
KHCNM s o 5/2015* CNKT HAM LO
Thong tin khoa hpc cdng nghe mo
cdng ngh0, trinh dp ky thuat phd dd duce su- dung. Song, do dup-c bo tri tren vung doi niii, boi tieh nen vCing mipng va co gilng, ddt da ehua ddng kit hogc ddng k i t chua b i n vD-ng ludn cd xu hudng djeh ehuyin theo hudng doc, chay theo eae sudn doi, niii, tac dgng len thdnh vo ehong gilng. Tiet dipn gieng dgng hinh trdn, la dang cd sy phdn bo irng suat ding d i u nhat vd khd ndng chiy tdc ddng cua tdi trpng (dp lye) idn nhdt. Nhung nhu dd phdn tich nguon goe vd ljch su hinh thanh khoi dat da phan boi lap tren, nen hudng tdc dgng cua ung sudt vd gid tn dg Idn eua lye tae dgng eung nhu gia tn ung suat khdng giong nhau. Mge dii ve nguyen 1^ irng suat phy thupc vdo chilu sdu (H) vd trpng lup'ng t h i tieh eua khli da quanh gilng (y). Hinh 1.
Vdnh mipng vd vanh chdn d l c6 gilng ehju tae dgng eua tai trgng cac edng trinh tren mgt (hinh 1). Tong tai trgng cua khoi kien true tdc dgng len vdnh mipng gilng vd vdnh d l c l gilng eao hay thap phy thugc vao vj tri dgt gieng, trong dd ben vung, nguyen khoi thi hp so lye day ngang (Am) nhd, cdn trong ddt da kem bin vung thi Am se Idn. Theo Ximbarevich [2], lye day ngang len vd ehong gieng cd gid trj (1):
;'.. =Cr,-A+ri ^ +r,AXgW - ^ ) (i)
Tgi ddy: tg^ (450 - ^ ) = A^ , Am Id lye day ngang, dug'c gidi thigu tgi bang 1
Khi ehilu eao Idp da thai va dat phu cdng Idn thi vide lya chgn kich thudc vdnh d l dd vd khoang cdch giu-a vdnh mi0ng gilng d i n vdnh
Hinh 1. M$t cit dia tdng die trwng cic khu vuc xiy di/ng gidng dwng vOng Quing Ninh d l dd e l gilng can dup'c nghidn cCi-u thgn trpng.
Tir dd, ed the rut ra nhu-ng nhdn djnh sau:
- Gilng dirng dug-e thi edng trong viing Quang Ninh, xuyen qua cdc via than cd goc die tir trung binh den doc, chilu ddy tir trung binh d i n ddy, Idp ddt da thai cung nam tren cac nen ddt ed gde d i e khae nhau. Vi vdy, vo ching thanh gilng dung chiu tae dgng khdng deu tie tit ca cde phia, nhung chu yeu theo hudng doc.
- Sy khdc nhau ve phucng, hudng eua luc tae dyng dug'c hinh thanh do cde y l u to ty nhien nen cung dong thdi hinh thanh u-ng suit quanh thdnh gilng vdi cdc gia trj khde nhau. Hay ndi Bing
Loai di 1 II III IV V VI VII Vlll XI X
1. Tri a6 cOa hisSluc diy ngang theo Ximbarevich Oac diem cua di
cat chay cat r&i C« * i ISn s « Ddyeu Bi m^m Bi trung binh Da tuong c36i ben eab6n ea tit b^n ea b^n nhat
Lo^i di die trung ciia nh6m di cat bgi c6 kich c& 0.1 - 0,15mm, d^t cat chay k[ch thyb-c kh6ng idn hen, flat Sit, dat trong trpt, cat mjn vi cac loai dit S6t deo, than bCin, than d6n
sat rSt b^n, da phin, da mu6i, than antraxit BOt k6t m4m, bit pha cat bin, cat k& mlm, cat ket ben, da v6i
ea bin vOng, cat hat mjn, qu$ng Granit, kvarxit, quang Pocfil, dioryt, bazalt, gneisy
He so liPC day ngang Am 0,5 - 0,6 0,25-0,35 0,15-0,2 0,12-0,13 0,08-0,12 0,04 - 0,07 0,01-0,085 0,006-0,009 0,003-0,005 0,001-0,003 KHCNM S6 5/20IS* CNKT HAM L 6
Thong tin khoa hpc cong nghe mo mgt each khdc irng suit phia canh nang cua via
tren vd ching gieng dirng cd gid tn Idn hen phia ednh chim cua via. Hai bdn hdng gilng gid tri Crng suit tgp tmng g i n nhu bdng nhau.
- Sy hinh thdnh vd x u i t hipn irng suit tdp trung quanh thdn gieng khdng can d l i , khdng cd gid tri nhu nhau ngay tren cung mdt mire Id rat cd the xay ra.
Van de nay da dup-c cdc nhd dja ec hgc d i t dd md nghien ciru tir r i t sdm [2]. Tir nhifng nam 1909, Farber ngudi Dire, hay sau dd Id Damke, Mohr, Link hay Bals da nghien ciru v l sy hinh thdnh vd tdp trung O-ng suat khdng can d l i quanh gilng dirng, theo dd:
- U'ng suit quanh gilng dirng tgp trung nhilu nhit vd cd gid tri Idn nhdt tai % chu vi dudng trdn cua mgt cat ngang qua than gilng.
- Gid tri giu'a irng s u i t Idn nhat (phia ednh nang cua Idp dd) vd nhd nhit (phia ednh hg cua Idp da) dug-e gpi Id gid trj h$ s l khdng cdn bang irng suit trong Idp da quanh gilng dirng. Gia tn irhg suit v l hai phia tren eung mgt eat ngang gilng dCrng gan nhu nhau...
Tir mgt cat d\a tang va ec sd ly lugn theo [6], cho thay:
- Khi gilng du-ng thi cdng qua cdc ldp dd ed gdc nghidng khdc nhau, thi dy tgi mdt eat yn*i, n l u ben phai gieng Id than vdi trgng lugng the tich cua than nhd thi ben trai mat cat gieng du-ng Id dd cd trgng lup-ng t h i tich cua da ya cao hen.
Tir dd, irng suit hai phia ben phai vd ben trdi gilng se khdng nhu nhau.
Hinh 2. Sw tip tning Ong sudt khdng cin ddi quanh gidng trong vOng ddt di khdng ddng nhdt, di hwOng
Khi gilng xay dyng trong viing dat phu nhu set, d i t nguyen tho, thi gde ma sat cua ddt thay doi rat idn vd phy thugc vao dO I m eua ddt. Khi dat khd, gde ma sat trong cd t h i len tdi 45°, nhung khi am hoae bao hod nudc. gdc ma sat trong chi edn 5° hogc thip hen. Khi dd, dp lye tdc dpng len co vd mipng gilng se dgt gid tri cao vd dup-c xdc dinh theo edng thirc:
„ 2 \r.h k
c + ii c c(c-\) (2) Trong dd:
h - Chilu sdu eua Idp dd, m;
R - Ban kinh vung biln dgng deo, m;
Hinh 3. Sw tip trung wng suit quanh gidng khi gidng dio xuydn qua cic ldp di cd gdc ddc a - Bdn kinh ben trong eua gilng, m;
1 -H sin(i7 l - s i n ? ?
k- Lye dinh cua dd, MPa
Khi Idp da viing biln dang deo cd the biln dang, ldm kich thude vung biln dgng deo "R"
tdng, khi dd lue nen len vd gilng se giam dan d i n 0, hay po = 0, vd dg Idn vung bien dgng deo quanh gieng se Id (3):
^ = < * . - ; i
c(c + l) {c-\)h.
..,]
(3)Vo'i goc nna sat trong ciia da (<p) nho, gia tri ciJa ty so R so vo'i a se r^t lo'n, vi du vo'i gieng sau 500m, pz = 1200N/cm2, k = 20N/cm2, 9 = 20°, c = 2 , tu'ong irng R = 21a, khi do vijng bien dsng deo dao dong trong khoang a < R < 21a.
KHCNM 8 6 5/2015* CNKT H A M L 6
Thong tin khoa hoc cong nghg mo
3. SiF U c dpng khong d i u cDa tai trong tren mlit d i t len g i l n g dtpng
NhLP da de c^p tren, viec xay dyng gieng tren mat mo la bSi thai, nen mat diit nguyen thuy la cac syon d6c, suoi nu'dc v.v... nen tai trpng tac dOng len giing, nhat la phan mieng va co gieng khong deu (hinh 1). Theo Farber [2], ap lye nay 6u/QC xac djnh theo cong thi>c:
p = p,.^^^( -+|sinQ;[) (4) Trong do:
p - Toan bp ap li/c tac dong len v6 ch6ng gieng, MPa;
po - Ap lij'c khong d i u ;
(0 - Mi>c do khong d6ng deu ve ap ii.j'c;
a - Goc nghieng theo hu*6ng tac dpng ciJa ap lye.
Theo Sterkowicz, myc dO khong dong deu ve tac dpng cua ap lye 0) = 1,1 + 1,15, con theo cao nha khoa hpc cua Nga, he s6 mij-c dO tae dpng khong dong deu eua ap lye len vo eh6ng gi§ng dyoc xac dinh theo eong thiJc (5):
(5) Trong do:
V - H$ s6 khong deu ve ap lye;
Psr- Gia tri ap lye trung binh;
PI- Gia tri ap lye tai diem xac djnh;
n - So lypng dilm xac djnh ap lye;
Gia tri ap lye cyc dai va eye tieu se la:
4. Nghien ci>u de xuat k i t c l u vo ch6ng gi§ng du'ng trong d i i u kien vung Quang Ninh Ty cac so do phan bo iJng sua! va hydng tae dpng lye len vo ehong thanh giSng dyng eo t h i nhan thay quanh vo ehong gieng dij'ng ngay tren eung mpt myc ehieu cao, tae dong eOa ap lye ngang va sy phan b6 iJng suat khong hoan loan gi6ng nhau nhy ehijng ta v i n nghT. Do la do khi gieng dao xuyen qua Idp vfa day doc. Tai phan canh nang cOa vfa ap lye tac dpng len vo ehong gieng diing Idn hon ca ve gia tri tuyet doi Iln sy tap trung ij-ng suat va gia tri Crng suat eda dat da quanh thanh gilng. Hay t^i vj tri nay, yng sulit mang dau "+". Vdi gia trj i>ng suat nen eao va
phia canh chim cua via t^i be mat thanh gilng gia tri ap lye ngang nho va Ong suit mang d i u
"-" nhieu hon.
Nhy v|y, viec bo tri cot thep ehju tai trong hay t^i vj tri gilng qua via c6 chilu day vi gde doc Idn phai chpn k i t eiu va vat lieu ching sao cho kha nang ehju nen va ehju keo cao hon so vdi cae vj tri khac. Theo [2], [6] sy t i p trung i>ng suit vi gia tri dp Idn ap lye d i y ngang ten thSnh vd ching gieng khi dao qua vfa co chieu d^y va goe d i e Idn phan b l ehO y l u tai mien g l c kSp theo hydng d i e vfa trong gidi han 90°(hinh 4). Ti> do, ta eo the lya chpn phyong phap gia c l de tang kha nang ehju nen, ehju u l n eua vo ehing gilng dijng theo ly thuyet tydng ehan.
Doi vdi cong tae thi cong va lap dyng eip pha d l thi cong vo ehong gilng di>ng theo doan dai hay doan ngin deu cd nhyng kho khan nhat djnh. Kho khan CO ban la vipc thay doi hinh dgng tilt dipn mat eat cop pha, nhat la d p pha trypi hay cop pha di dpng. Ly thuylt tu-dng ehln khong chr d l tinh toan ap lye ma eon de chpn ket eau thep va bo tri c l t thep. De eo eae gan gia tang kha nang ehiu ap lyo d i y hong tai cinh nang eiJa vfa va ap lye keo hong tai phin canh chim, xay dyng eae tydng ho trp nhy hinh 4.
Viee xay dyng eao gan gia cydng, v l ly thuylt, cd tac dpng kha tot doi vdi kha nang mang tai va kha nang ehIng bien dang eua vo ehong thanh gilng dij-ng. Tuy nhien, vin de dat ra d day la xay dyng mgt gan tang cydng khi gieng dyng thi eong dao xuyen qua via day va doe la vj tri ap lye va yng suit tac dpng len vo ehpng thanh gilng dyng Idn nhat.
Trong thye t l , de thi eong vanh de gilng di>ng mpt eong doan thi eong gia cydng vo ehong gieng di>ng thong dung eung gap khong it kho khan khi tao hinh dgng vanh d l dd vdi mcii die hinh con. Vi#c xay dyng gan gia cydng theo hinh 4 ehi mang tinh ly thuyet. Thye t l , gan gia cydng khong nhat thiet phai eo mat cat dpc dang hinh tam giac ma eo t h i d?ng hinh chO nhjt.
Nhyng de tao dyp'c gan hinh ehu' nhat, cong tac khoan pha tao hinh va thi edng be tong gSn gia cydng eung r i t kho khan.
Oe tang kha nang ehong uon, ehong biln dang vo ehong gilng diing theo mat elt ngang va dpc theo ehieu eao gilng dyng, eo the thay
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Thong tin khoa hoc cong nghe nno
Hinh 4. Sa di vi tri xiy dung gin ting cudng ^ ^ dii v6l v6 ching bi tdng cit thip gling dirng
khi thi cdng qua via diy doc the gan gia cydng bang vipc bo tri eae eot thep d l gia tang kha nang ching uon, ehong keo va tang dp b i n cho vo ehIng be tong thanh gilng.
Theo [2], d l gia cydng, tang kha nang ehIng bien dang va tang dp ben ehong u l n theo ehieu thing diing cua gilng diing, nen tinh toan thiet k l va b l sung them cae elt thep tang cydng. Tai eung vinh gilng vdi gde 90° theo hydng doe cua via, nen b l tri cae eot thep diing vdi khoang caeh nho hon. Dong thdi, cac cot tiiep theo chu tuyln eung sii dung eae loai thep eo kich cd Idn hon. Vipc b l tri them cot thep trong goc eung 90°
khong qua ton kem ma hieu qua cao. Theo do, cac cot thep thang diing chpn loai i/ 24mm thay eho th4p If 22mm hay thay th6p vdng If 18mm bang thep i/ 20mm, eung nhu' tang mat dp eot thep gia cydng (hinh 5).
5. K i t l u | n
Thi cdng xSy dyng dao sSu va ehong giy vd ehong gilng diing trong dilu kipn dja chit cong trinh va dja chit thuy van phiic tap nhy viJng Quang Ninh khi mipng eo va than gilng diing nam trong viing d i t da khing I n djnh, goc doe va ehilu day via Idn, dp ben than thap nen r i t d l xuat hien iing suit va ap lye mo phan bo va tac dpng khdng can dpi len vd ching gieng. Mat khac, dilu kipn dia chit thuy van, vdi nydc mo ed tinh an mon kim loai eao, lypng nydc thim qua thinh gilng Idn \i nguy co t i l m an v l sy an mdn kim loai va an mon be tong. Nhiing tiem an do d i l u ki^n dja c h i t cong trinh, dia chit thuy van la nguyen nhan lam giam tuli thp vd ehong gilng
Hinh 5. So' di bi tri cit thip gia cudng tai vung ting ip luc vi Ung suit trin thinh vd ching gling
thi cdng trong khu vuc via diy die.
D l tang cydng miic dp on djnh va kha nang lam vipe lau dat cua vd ehong va c l t gieng diing, can cd nhiing nghien ciiu ly thuyet va thyc nghipm de dap iing nhiing kho khan do sy thay doi dja CO hoc da va khoi da gay nen. Can nghien ciiu theo hu'dng gia tang miic dp dn i^nh va kha nang mang tai eua vd ehong gilng bing cae giai phap gia tang kha nang lam viee cua k i t c l u va vat lipu ehong gilng, trong do, xem xet d i n viee SUP dung, bo tri phu hpp elt thep trong vung vd ching gieng bj tac dpng mpnh cua ling suit va ap lye. Lya chpn va sii dung be tong dp ben cao phoi hyp vdi k i t c l u cot thep hpp ly la giai phap tilt kiem d l thyc hien phu hpp vdi dilu kipn kinh t l , ky thuat cua nydc ta./.
Tai lieu tham khao:
1. Vo trpng Hung, Phiing Manh Oac (2005), Ca hoc di - Ohg dung trong xay dijng cong trinh ngam va khai thac mo. NXB Khoa hpc va Ky thuat Ha Noi.
2. M. Boreeki., M. Chudek., Mechanika Gorot- woru., (1978) H^dvm/chv S/as/c-Katowice.
3. AnHMjKaHOB A. M., (2012) llpocmpacmeeH- Han OcecuMMempu^Hafi VcmoQ^ueocmb Bepmu- KanbHoO CkeaxuHbi B Maccuee Codepxau^oM Cnou C tlOHUMeHHbiMU ripcHpocmHbiMU CeoO- cmeaMU, KaaaxcKwCi HauHOHanbHbiM TexHMMecKMti yHMBepcMTTer HMPHH K V\ CaMTaeaa AniviaTbi.
4. B.H. ApMeiieKOB ilpoeKmupoeauue MOHO- numnoq BemoHHOu Kpenu BepmuKanbubix Cmeo- noe Vnpo^eHHHOLi xenesoSemoHHbiMU AnKupaMU.
5. AP"5aH B. A., CeepKiKOB A. O., (N° 11.2012) OGecnmeHue VcmoiMueocmu HiyBokux Bepmu- KanbHbix Cmeonoe e Pauonax feonoau^eckux Ha- pyuiOHUu moHeuf< YKpH^Mkl.
6. BOPMCOBCC, (1988) FopHoefleno., MocKsa
"HeApa".
KHCNM S6 5/2015* CNKT HAM LO
