Sự hình thành, phân bố ứng suất và mối liên hệ giữa ứng suất với kết cấu vỏ chống khi thi công giếng đứng trong vùng quảng ninh

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 TS PHAM MINH OUC the coming time, the coal sector needs to carry out the coal mining operations at the deeper mining depth for Increasing theViin khoa hoc COng nghd Md- Vinacomin coal output, therefore, a series of new mines with vertical shafts Bien t$p: TS Trvomg Dufc Dif 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 loadcarrying 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 Md'ddu Trong md ham Id md via bang gieng dung, thdi gian ton tgi cua gieng dOng bdng tu6i md, dd, ket cau ehong gieng dung phai dam bao on djnh 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, phan hod hgc than viing Quang Ninh cd ham lup'ng luu huynh (S04) eao, hdu nong am Them vdo dd, gieng thudng dug-c xdy dyng d\hu kidn be mat dat phu Id dat dd rdi rac tren todn bd dogn mipng vd cd gieng, phan mc cdng nghp, thdn gilng ddo qua eae Idp dd vd than cd chilu ddy vd gdc doc Idn Dilu 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 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 S y hinh thdnh vung irng sudt tap trung, qua trinh phan bd irng sudt va tai trpng gidng di>ng ddo qua cac lap ddt da khac Dieu kien cau tgo Idp dat dd phu tren Idp da goc vung md Quang Ninh dug-e md ta khd day du cdc du an xay dyng cdng trinh khai thdc than xuong sau tgi cdc md ham Id md vfa bang gieng dung 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 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 kit chua sau, cdc hat dat da dup'c dua vao md hinh tinh cd tinh rdi rge cao Trong dd, edng trinh xdy dung tang dd goc md hinh dat da dug'c xay dyng cd dang cdc khdi, Idp Khi xay dung mieng, co va thdn gilng ddt dd vd khoi dd, xung quanh 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 sudung Song, dup-c bo tri tren vung doi niii, boi tieh nen vCing mipng va co gilng, ddt da ehua ddng kit hogc ddng kit 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 diu 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 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 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 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, dd ben vung, nguyen khoi thi hp so lye day ngang (Am) nhd, cdn ddt da kem bin vung thi Am se Idn Theo Ximbarevich [2], lye day ngang len vd ehong gieng cd gid trj (1): Hinh 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 nhu-ng nhdn djnh sau: - Gilng dirng dug-e thi edng viing Quang Ninh, xuyen qua cdc via than cd goc die tir trung binh den doc, chilu ddy tir trung binh ;' =Cr,-A+ri ^ +r,AXgW - ^ ) (i) d i n ddy, Idp ddt da thai cung nam tren cac nen ddt ed gde d i e khae Vi vdy, vo ching Tgi ddy: tg^ (450 - ^ ) = A^ , Am Id lye day gilng dung chiu tae dgng khdng deu tie tit ca cde phia, nhung chu yeu theo hudng doc ngang, dug'c gidi thigu tgi bang - Sy khdc ve phucng, hudng eua luc Khi ehilu eao Idp da thai va dat phu cdng Idn tae dyng dug'c hinh cde y l u to ty nhien thi vide lya chgn kich thudc vdnh d l dd vd nen cung dong thdi hinh u-ng suit quanh khoang cdch giu-a vdnh mi0ng gilng d i n vdnh thdnh gilng vdi cdc gia trj khde Hay ndi Bing Tri a6 cOa hisSluc diy ngang theo Ximbarevich Lo^i di die trung ciia nh6m di Oac diem cua di cat chay cat bgi c6 kich c& 0.1 - 0,15mm, d^t cat chay k[ch thyb-c kh6ng idn hen, flat cat r&i C« * i ISn s « Sit, dat trpt, cat mjn vi cac loai dit S6t deo, than bCin, than d6n Ddyeu sat rSt b^n, da phin, da mu6i, than antraxit V Bi m^m BOt k6t m4m, bit pha cat bin, cat k& mlm, VI Bi trung binh cat ket ben, da v6i VII Da tuong c36i ben eab6n ea bin vOng, cat hat mjn, qu$ng Vlll ea tit b^n Granit, kvarxit, quang XI ea b^n nhat Pocfil, dioryt, bazalt, gneisy X Loai di II III IV KHCNM S6 5/20IS* CNKT HAM L He so liPC day ngang Am 0,5 - 0,6 0,25-0,35 0,15-0,2 0,12-0,13 0,08-0,12 0,04 - 0,07 0,01-0,085 0,006-0,009 0,003-0,005 0,001-0,003 Thong tin khoa hpc cong nghe mo mgt each khdc irng suit phia canh nang cua via tren vd ching gieng dirng cd gid tn Idn hen phia ednh chim cua via Hai bdn hdng gilng gid tri Crng suit tgp tmng g i n nhu bdng - Sy hinh thdnh vd xuit hipn irng suit tdp trung quanh thdn gieng khdng can d l i , khdng cd gid tri nhu tren cung mdt mire Id rat cd the xay Van de da dup-c cdc nhd dja ec hgc d i t dd md nghien ciru tir rit sdm [2] Tir nhifng nam 1909, Farber ngudi Dire, hay sau dd Id Damke, Mohr, Link hay Bals da nghien ciru v l sy hinh thdnh vd tdp trung O-ng suat khdng can d l i quanh gilng dirng, theo dd: - U'ng suit quanh gilng dirng tgp trung nhilu nhit vd cd gid tri Idn nhdt tai % chu vi dudng trdn cua mgt cat ngang qua than gilng - Gid tri giu'a irng suit Idn nhat (phia ednh nang cua Idp dd) vd nhd nhit (phia ednh hg cua Idp da) dug-e gpi Id gid trj h$ s l khdng cdn bang irng suit Idp da quanh gilng dirng Gia tn irhg suit v l hai phia tren eung mgt eat ngang gilng dCrng gan nhu 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, nlu 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 Khi gilng xay dyng 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 cd t h i len tdi 45°, nhung am hoae bao hod nudc gdc ma sat 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: „ \r.h c + ii c k c(c-\) (2) Trong dd: h - Chilu sdu eua Idp dd, m; R - Ban kinh vung biln dgng deo, m; Hinh Sw tip trung wng suit quanh gidng gidng dio xuydn qua cic ldp di cd gdc ddc a - Bdn kinh ben eua gilng, m; -H sin(i7 l-sin?? 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, 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): ^=c khong d6ng deu ve ap ii.j'c; Doi vdi cong tae thi cong va lap dyng eip pha a - Goc nghieng theo hu*6ng tac dpng ciJa ap d l thi cong vo ehong gilng di>ng theo doan dai lye hay doan ngin deu cd nhyng kho khan nhat Theo Sterkowicz, myc dO khong dong deu ve djnh Kho khan CO ban la vipc thay doi hinh dgng tac dpng cua ap lye 0) = 1,1 + 1,15, theo cao tilt dipn mat eat cop pha, nhat la d p pha trypi nha khoa hpc cua Nga, he s6 mij-c dO tae dpng hay cop pha di dpng Ly thuylt tu-dng ehln khong dong deu eua ap lye len vo eh6ng gi§ng khong chr d l tinh toan ap lye ma eon de chpn dyoc xac dinh theo eong thiJc (5): 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 (5) chim, xay dyng eae tydng ho trp nhy hinh SiF Uc dpng khong d i u cDa tai 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 6u/QC xac djnh theo cong thi>c: 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 gilng dij-ng Tuy nhien, vin de dat d day la xay dyng mgt gan tang cydng gieng dyng thi eong dao xuyen qua via day va doe la vj tri ap lye va yng suit tac dpng len vo ehpng gilng dyng Idn nhat Trong thye t l , de thi eong vanh de gilng Nghien ci>u de xuat k i t c l u vo ch6ng di>ng mpt eong doan thi eong gia cydng vo gi§ng du'ng d i i u kien vung Quang Ninh ehong gieng di>ng thong dung eung gap khong Ty cac so phan bo iJng sua! va hydng tae dpng lye len vo ehong giSng dyng eo t h i it kho khan tao hinh dgng vanh d l dd vdi mcii nhan thay quanh vo ehong gieng dij'ng tren die hinh Vi#c xay dyng gan gia cydng theo eung mpt myc ehieu cao, tae dong eOa ap lye hinh ehi mang tinh ly thuyet Thye t l , gan gia ngang va sy phan b6 iJng suat khong hoan loan cydng khong nhat thiet phai eo mat cat dpc dang gi6ng nhy ehijng ta v i n nghT Do la hinh tam giac ma eo t h i d?ng hinh chO nhjt gieng dao xuyen qua Idp vfa day doc Tai phan Nhyng de tao dyp'c gan hinh ehu' nhat, cong tac canh nang cOa vfa ap lye tac dpng len vo ehong khoan pha tao hinh va thi edng be tong gSn gia gieng diing Idn hon ca ve gia tri tuyet doi Iln sy cydng eung rit kho khan Oe tang kha nang ehong uon, ehong biln tap trung ij-ng suat va gia tri Crng suat eda dat da quanh gilng Hay t^i vj tri nay, yng sulit dang vo ehong gilng diing theo mat elt ngang va dpc theo ehieu eao gilng dyng, eo the thay mang dau "+" Vdi gia trj i>ng suat nen eao va 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: KHCNM s o 5/201S' CNKT HAM L Thong tin khoa hoc cong nghe nno Hinh So' di bi tri cit thip gia cudng tai vung ting ip luc vi Ung suit trin thinh vd ching gling thi cdng khu vuc via diy die Hinh Sa di vi tri xiy dung gin ting cudng ^ ^ D l tang cydng miic dp on djnh va kha nang dii v6l v6 ching bi tdng cit thip gling dirng lam vipe lau dat cua vd ehong va clt gieng diing, thi cdng qua via diy doc can cd nhiing nghien ciiu ly thuyet va thyc the gan gia cydng bang vipc bo tri eae eot thep nghipm de dap iing nhiing kho khan sy thay d l gia tang kha nang ching uon, ehong keo va doi dja CO hoc da va khoi da gay nen Can tang dp bin cho vo ehIng be tong gilng nghien ciiu theo hu'dng gia tang miic dp dn i^nh Theo [2], d l gia cydng, tang kha nang ehIng va kha nang mang tai eua vd ehong gilng bing bien dang va tang dp ben ehong uln theo ehieu cae giai phap gia tang kha nang lam viee cua kit thing diing cua gilng diing, nen tinh toan thiet c l u va vat lipu ehong gilng, do, xem xet k l va b l sung them cae elt thep tang cydng Tai d i n viee SUP dung, bo tri phu hpp elt thep eung vinh gilng vdi gde 90° theo hydng doe vung vd ching gieng bj tac dpng mpnh cua ling cua via, nen b l tri cae eot thep diing vdi khoang suit va ap lye Lya chpn va sii dung be tong dp caeh nho hon Dong thdi, cac cot tiiep theo chu ben cao phoi hyp vdi kit c l u cot thep hpp ly la tuyln eung sii dung eae loai thep eo kich cd Idn giai phap tilt kiem d l thyc hien phu hpp vdi dilu hon Vipc b l tri them cot thep goc eung 90° kipn kinh t l , ky thuat cua nydc ta./ khong qua ton kem ma hieu qua cao Theo do, Tai lieu tham khao: cac cot thep thang diing chpn loai i/ 24mm thay Vo trpng Hung, Phiing Manh Oac (2005), Ca eho th4p If 22mm hay thay th6p vdng If 18mm hoc di - Ohg dung xay dijng cong trinh ngam bang thep i/ 20mm, eung nhu' tang mat dp eot va khai thac mo NXB Khoa hpc va Ky thuat Ha Noi thep gia cydng (hinh 5) M Boreeki., M Chudek., Mechanika Gorotworu., (1978) H^dvm/chv S/as/c-Katowice K i t lu|n AnHMjKaHOB A M., (2012) llpocmpacmeeHThi cdng xSy dyng dao sSu va ehong giy vd ehong gilng diing dilu kipn dja chit cong Han OcecuMMempu^Hafi VcmoQ^ueocmb Bepmutrinh va dja chit thuy van phiic tap nhy viJng KanbHoO CkeaxuHbi B Maccuee Codepxau^oM Quang Ninh mipng eo va than gilng diing Cnou C tlOHUMeHHbiMU ripcHpocmHbiMU CeoOnam viing d i t da khing I n djnh, goc doe cmeaMU, KaaaxcKwCi HauHOHanbHbiM TexHMMecKMti va ehilu day via Idn, dp ben than thap nen rit yHMBepcMTTer HMPHH K V\ CaMTaeaa AniviaTbi B.H ApMeiieKOB ilpoeKmupoeauue MOHOd l xuat hien iing suit va ap lye mo phan bo va tac dpng khdng can dpi len vd ching gieng Mat numnoq BemoHHOu Kpenu BepmuKanbubix Cmeonoe Vnpo^eHHHOLi xenesoSemoHHbiMU AnKupaMU khac, dilu kipn dia chit thuy van, vdi nydc mo AP"5aH B A., CeepKiKOB A O., (N° 11.2012) ed tinh an mon kim loai eao, lypng nydc thim qua thinh gilng Idn \i nguy co tilm an v l sy an OGecnmeHue VcmoiMueocmu HiyBokux Bepmumdn kim loai va an mon be tong Nhiing tiem an KanbHbix Cmeonoe e Pauonax feonoau^eckux Hado dilu ki^n dja chit cong trinh, dia chit thuy pyuiOHUu moHeuf< YKpH^Mkl BOPMCOBCC, (1988) FopHoefleno., MocKsa van la nguyen nhan lam giam tuli thp vd ehong "HeApa" gilng KHCNM S6 5/2015* CNKT HAM LO ... [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, nlu ben phai gieng Id than vdi trgng lugng the tich cua than nhd thi ben trai mat cat... gdc ma sat 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: „ \r.h c + ii c k c(c-\) (2) Trong dd: h - Chilu sdu eua... 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 nhu-ng nhdn djnh sau: - Gilng dirng dug-e thi edng viing Quang Ninh, xuyen qua cdc via than