Thflng tin khoa hpc c6ng ngh$ m6 w NGHIEN CCfa CfiC Gl(1l PHfiP i\Ai\G CAO oi\ nii\ii is(> i>i6 I O Tiiiftrv Up to now the solutions for increasing the open pit slope stability have been classified in[.]
Thflng tin khoa hpc c6ng ngh$ m6 w NGHIEN CCfa CfiC Gl(1l PHfiP i\Ai\G CAO oi\ nii\ii is(> i>i6 I.O Tiiiftrv Up to now the solutions for increasing the open pit slope stability have been classified into three main groups such as hydraulic, mechanical and chemical ones Jn this paper the authors introduce some fundamental methods that have been studied for increasing the open pit slope sl.il^ilily Hifin t^i vd nhung ndm t6i, cdc mo Ifi thifin sdu cua nuac ta ngdy edng xuing sdu, dieu kifin dja chat cfing trinh - dja chit thuy vdn phiPc tgp, nhieu mo dang phai doi m$t vfi'i hlfin tuyng tm'ot la bo mo gay mit an todn cho ngufi-i, thilt bj vd Idm giam hifiu qua san xult kinh doanh cho edc doanh nghifip Tie d6, vific nghien CLHU ndng cao dfi on dinh eho cde bfi* mfi Id rit c l n thilt Tu nhung kinh nghifim thyc t l vd ngoai nufi'c, bai bdo ndy gid'i thifiu mfit so phuang phap, giai phdp nang cao dfi on djnh bfi' mo Phu^yng phap hoa hgc - phun be tong Be tong phun duac su dyng rfing rdi de nang cao I n dinh cde bfi" dfic dd cung nhu cdc h i dao sau Ndng eao on djnh cua bfi' doc dit 16' tich, tdn tich va dd phong hod nham ngan chdn sy xfii mon, Id" rfi'i 6" mdi die Be tong phun cung duyc dp dyng dfi sua chCra nhung chd be tdng bj phd huy, hu hai vd dfi phun lot ede kenh ddo, ho chira vd b l bai Be tong phun dac bifit cfi hieu qua d l ndng eao on (Snh 6" ede cfing trinh ngam, thufi'ng kit hap vfi'i iufi'i thep, vd c l n thiet, k i t hyp vo'i khung thep nhe Be tong phun giup cho sy tiep xuc chat che gi&a kit c l u chong v6'i b l mat dit da vd lam giam thilu sy dich chuyin eua khoi dd Be tong phun Id vfit lieu co ban phuang phap ddo 16 kieu mo'i cua Ao (NATM), Vo ching mem deo sii' dyng be tfing phun kit hop luoi thep cfi kha nang chju duyc cac chin dong nfi min, ca vol cdc vy no gan, hifiu qua han so vfi'i vo chfing be tong eirng, Co hai phuang phap phun be tfing, phun khfi va phun ufi-t Trong phuang phdp phun khfi (hinh 1a), cdc cot lieu thfi va min, xi mang vd dfii bgt dfing eirng nhanh, d- dang khfi hoae nua ThS LUU VAN THl/C KS LE XUAN THU KS vu HAI DANG KS NGUYEN VAN DD'C Vidn Khoa hQC Cdng nghd Md-Vinacomin khfi, duac bam bing nfin qua Ing clp lifiu phun Ifin b l mfit efing trinh, bfi- mfi v.v Vfi'i phuang phdp phun yfi-t (hinh 1b, Ic), be tfing phun cfi ede thdnh phin khfi vd ufi't trfin vol gilng nhu bfi tfing thufi'ng vd cOng duoc phun Ifin be m|t efing trinh Trong hai phuang phdp tren, be tong phun khfi eho cdc kit qua tot hon vd dfi bin 16'n hon Phuang phdp phun khfi cung cho phep bo sung chit phu gia tdng b i n nhanh tgi mui vfii phun Tuy nhien, phuang phdp phun khfi phdt sinh nhilu byi va ldng phi vfit lieu Phuang phdp phun ufi't lai e6 uu dilm, d6 Id thudn lai vific vfin chuyin be tfing phun d i n chdn cfing trinh vfi'i cde xe cho' be tfing ehuyen dung Ngodi ra, phuang phdp phun ufil, ty Ifi nuac/xi mdng duoe kiem sodt ddy du, phuang phdp phun khfi dfii hoi ngufi-i dieu khien phdi cfi nhieu kinh nghiem d l dieu tilt luang nufi'c Hifiu qua phun be tfing se cao hon nlu phun a PhiKfng phip phun khd; b Phuvng phdp phun ud'f dung ndn; c Phwong phdp phun u&t dung bom bd tong Hinh Cdc phuvng phdp phun be tong KHCNM s d 8+9/2012* CNKT LO TIIIEN Thflng tin khoa h(?c cflng ngh$ nnfl âã vudng gdc vdi b i mdt cing trlnh, dd, g i n ddy ngydi ta cd xu hydng nghidng v i vide dp dyng phyong phdp phun u'dt diiu khiin tif xa, vdt lidu phun cd b i sung thdm chit microsillca vd sgi thdp Ddy chuyin cing nghd phun gia cydng b i mdt dygc t h i hidn trdn hinh 2, iu,rtim tm 011441 vj dtn o£n diy rao ^^^^ ai«4iv4dlynBDifldfcimo Dinh luvng; Miy trdn khd; Mdy phun khd: Du&ng dng din • Vdi phun Diiu khi6n Hinh Sor day chuyen cong ngh§ phun gia cu^g be m$t Tw < T, dd lim gidm thidu mdt mit cSng tru&c chiu tdi trgng chu ky Hinh Qua trinh cdng kdg neo Can cir vao ddc tinh vd uu diem cua cfing nghe phun be tfing cung nhu dac diem tinh chit CO ly dit da va dieu kifin khai thdc eua mfit s l mo, cdc kit qua nghien cuu cho thiy, phuang phdp be tfing phun cfi t h i dp dyng de gia euo'ng be mat bo' tru via 13.1 mo than Tdy Nam Da Mai, bo try Nam, mo than Na Duang Phwong phap co'hgc Trong viec nang cao dfi I n djnh cho bd" mo, phuang phdp co hpc duyc nghien cit'U dp dyng nhieu nhat hlfin Id phuang phap neo nong (thanh neo) vd neo sdu (CQC neo) Phuang phdp thufi'ng duac dp dyng nhung truong hap gia CO cho cdc ho dao sdu, on djnh mai die, fin dmh edc ho ddo ngim I n dmh cdc kit c l u moi va hlfin cfi, an todn cho kit c l u chiu tai trpng thing dung va di ehuyen • Neo mdi doc da: Vific dimg neo de dam bao on dmh cua mai die da, cdc ho dao ngim d i t da c6 the dp dung cho hau h i t cac logi d i t da Tuy tifng truong hop, neo c6 the duoc dung lam phuang tifin neng de tao on dmh hoac su dung ehung phli hop v6'i cac dgng gia co khac nhu be tfing phun, xa thep, kit cau giua bdng be tong, vv,,, Pham vi dp dyng cua neo duoc tong hyp P^ KIICN,MS()«t')2l)l2'(;NMI.Oni[L\ a TrwQt diy ho$c tiieo mit l&p; b Truot tr&n cic khe nut c TrwQt trdn chd dui doan hodc cic mit nghidng: d Ldt e Ndm phd huy Hinh Cdc kieu phd huy mai doc bang Sa cang, keo neo va cac dgng neo mdi doc duoc the hien tren hinh va 4, D I ehl d i n , dfi sdu cua neo cfi t h i duyc xac djnh bdng cdch dung cae thfing so thich hap cong thirc cua bang Thflng tin khoa hgc cflng ngh$ mfl w Bang Cac dieu ki^n dd vd dp dyng gia c6 Loai gia co Chot dd Bu ldng dd Neodd Cdc didu kl^n dd vd dp dyng D l dam bdo fin djnh cOa vCing rdt gdn bfi mdt ddo; Gia cfi cho dd sfi bdc di giai do$n sau; Gia c l chung d u y c ddt r i t g i n b l mdt cd tru'dc, hinh thdnh lyc kdo sau ddt; l gia c l trudc ddo Phy hop cho mpi logi d i t dd, dd y l u , c l n cd c h i l u ddi phili hyp d^ cd t h i tgo d u y c dfi ben chiu kdo cho c h l l Ap dyng gia c l chung cho moi logi ddo d i t hfi - Bu Ifing cd b l u k i l u co hpc chi thich hyp sir dyng dd cu'ng - Bu Idng cd b l u phun vi>a cd t h i dung mpi logi dd Khi dd y l u hofic l i n d i t sdt, cd the sUc chju tdi ciia neo khfing du thi dung b l u neo phun vua cao su Ap lyc c h i n g Ifin n h i f 300kN/m^ Ap dyng gia cfi cdc hfi ddo hfi' ldn ddi hdi dp lyc chdng dd* cao vd chidu ddi gia cd ldn Chu y l u dung p h l i hyp vfii bu Ifing, c h i t ho$c bd tfing phun Thich hyp cho mpi logi dd, n h i t Id dd c h i t iuyng t h i p d u y c lifin k i t cung hodc da vun, mdt truyt n h l n cdc khe niPt du'oc l i p diy, ddng nu'dc mgnh, ung s u i t tgi chd cao, dd troi ien hay bl nfin mgnh, Ap lyc c h i n g nhfi n h i t 200kN/m', Ap lyc c h i n g ldn n h i t 600kN/m^ Ap luc chdng = dp lyc chdng c6 duxyc t$i th&i diem lip d$t Bang Xdc djnh sdu cua neo Cdng th&c cho dg sau neo Da khong dong nhat Chu y Tuyen nhieu neo Mpt neo s,r„ 44rJ Da nu't ne khdng theo quy ludt Da nu't ne bi ngap khdng theo quy luat Sr=2-4 Gdc dinh bdng 90° (gia thilt) 3-f,7;, (y-r.W" ir - r».)^f}i~^ Trong cac cong thuc & bang T-OQ bin chiu cdt cua dd kN/rn^; Si - He sd an toan vi phi hoai (thuc ti thu&ng liy Si=2^ 3), s~ Khoing cdch giua cic neo m, - Gdc ma sat tai cdc vi tri dut gay khdi di dd; 7* - 7a/ lam vide tren neo kN y - Trpng luong don vi cua da kN/m^ Mat phang phS hi P h u a n g phap phan tich s u fin dinh eua neo mdi dfic da d u a c gid'i thifiu tren hinh 5, a Hinh dang khdi mo ta cdc lyc, nguyen tac dgng tren khdi Lijcca bin Phan luc phap tuyfin n Thanh phin mit phdng phd hoai Hwdng W W I = Wsinp Wn = Wcosn tg* Trpng luc Ngu'cc hudng chuyen dich T Tl = Tcos (6 + p) Tn = Tin(0 + p)tg(D' Mai ddc tren Mai d i e du'di Ngu'O'c hudng chuyin dich • W- Trong luang khdi Hinh Phan tich sy on djnh cOa cdc mdi ddc da tic KIICNM SO 8*') 21112' ( N K r I.O TlIlf.N Thflng tin khoa hgc cflng ngh$ mfl W' chi>a nydc c i dp vd khdng dp Phin Idn cdc mo d i u dyiyc thiit k i khai thdc vdl mdt bd cdng tdc, Tdng cic lifc chSng chuyin djch dd, trdn md hinh thdnh hai dang bd Id bd cdng Hi si an loin Sl= jing cic Ivc giy chuyin dich tdc (bd vdch) vd bd khdng cdng tdc (bd tm) Bd trg d i u dydc thiit k i bdm tM lidn tuc, Dang cua hd ndy phu thudc vdo cdc dd Idn vd hydng tyong d i i oCia cdc lyc tdc ding, til'c vdy a|a ting tru g i n nhy khing d i i qua trlnh khai thdc xuing sdu, Diiu ndy din din cdc Id, ting chCra nydc ngim dyp'c bao t i n dd tao nen dp lyc thuy ddng tdc dyng Idn khii dd bd tn,i gdy trypl Id bd tru chiiu cao cua bd Mtrql qud chiiu cao gidi han cho phdp cua bd (0 + |J)< 90°, T, > w, thi St = (2) D i ndng cao i n dinh cho bd khdng cdng tdc T, bd md chju i n h hydng cua nydc ngim d T,+W, d^ing cd dp vd khdng dp, gidi phdp thuy lyc dycc (3) (e + p) ( \ K T I.O TIIIEN ... Idn khii dd bd tn,i gdy trypl Id bd tru chiiu cao cua bd Mtrql qud chiiu cao gidi han cho phdp cua bd (0 + |J)< 90°, T, > w, thi St = (2) D i ndng cao i n dinh cho bd khdng cdng tdc T, bd md chju... neo khfing du thi dung b l u neo phun vua cao su Ap lyc c h i n g Ifin n h i f 300kN/m^ Ap dyng gia cfi cdc hfi ddo hfi'' ldn ddi hdi dp lyc chdng dd* cao vd chidu ddi gia cd ldn Chu y l u dung... S = H -\ H'' -2q \n-^ (9) Trong dfi: H- Chieu cao muc nufi''c ban ddu, m; Qt- Luu luang cua ting chua nufi''c, m^/ngdy Muc tieu cua thdo khfi Id giam cao trinh nufi''c ngim, tu dfi, giam dp lue nufi''c