Thpng tin khoa hpc cong nghe mo \4JGHIEN CI)U LU'A CHON GIAI PHAP DAM BAO ON DjNH CHO ztfma nan no THfiN t>EO Nfii Recently, in the coal mining process, at the South slope TS LUUVANTHI/C of Deo Nai coal mine, there have the failure phenomena KS Le XUAN THU Basing on the determined reasons causing failures, the ThS D6 KI^N CLJ'6'NG researchers have selected the solutions for ensuring the Vi$n Khoa hoc Cdng ngh$ M6 - Vinacomin stability at the South slope to the level of -345m as its Bien tap: KS Ph^m D$i Hai scheduled design Bd try Nam, md than Deo Nai, qud trinh khai thdc, nhieu ndm dd lien tyc xdy trugl Id Tren eo sd nguyen nhan tnj-gt da duge xdc tSnh, tien hdnh nghien ciru lya chpn giai phdp dam bao I n djnh cho bd try khai thdc den k i t thue -345m theo thiet k l Be tdng phun cOng cd hieu qua doi vdi dit, edt vd dd dam rdi rac Be tdng phun dgc bigt ed hieu qud d l nang cao on djnh d cae cdng trinh nglm, thudng kit hgp vdi ludi thep vd c l n thiet, kit hgp vdi khung thep nhe; nd Id vgt ligu eo ban thi Cdc kit qua nghien ciru trudc day ve on d\nh edng dudng ham Ao kilu mdi Hg thing be cua bd md Deo Nai da xdc dmh nguyen nhan tdng phun tri sy tiep xue chat che vdi mat gdy trugt Id cua bd try Nam, md than Deo Nai dd vd cung giam sy djch chuyin eiia dd d i n Theo dd, vigc trugt Id cua bd try Nam dugc mire dp nhd nhit Cd hai phuong phdp phun be quylt djnh bdi cde y l u t l ty nhien vd cdng nghe, tdng, phun khd vd phun udt nhu c l u triic dja tang, tinh ehIt bin, dae tinh Gia c u v n g khdi da va cac mgt y l u bang ehira nudc vd tdng tru nudc nglm cung nhu luu giai phap xi mang hoa sau thdng nudc dja ting [1 ], [2] Cdc thdng s6 Xi mdng hod sau Id bom phyt dung djch xi cua hg thong khai thdc, nhu chilu cao bdm try mang lap day cde lo rdng, khe nut eua d i t dd lien tyc vugt qua chilu cao I n djnh gidi han cho Dudi dp lye bom phyt nhat dinh, thdng qua ede phep lo khoan hay gieng dirng nham tang cudng dp Bd try Nam dugc c l u tgo bdi cae Idp da elm bin, kha ndng ehju tdi vd ngdn chan ddng ngam, vdo khdng gian khai thdc vdi gdc doc tir 25-^35°, nang cao dp on djnh eho bd md, giam hg so dja ting t i n tgi ede mat giam y l u ty nhien tham nude cua dat dd phan bo sau dja theo tilp xiie Idp vdi dp ben rat thap (C'=0,017 tang MPa; cp=17.0°), nudc nglm cd mgt dia Gia cud'ng mai d i e bdng neo tang dudi dgng khdng dp, hlu nhu khdng dugc Vigc diing neo de dam bao on djnh eua mai hg thap qud trinh khai thdc xuong sau, doc da mdi hoac da cd vd cdc ho dao nglm do, chilu cao I n djnh gidi han cat tang theo dd dd dugc thilt lap tot cho hau hit cde mgt Idp (a = p) H £ 120m De nang eao on djnh loai dd Tuy theo hoan canh quy djnh, cdc neo cho bd try cd t h i lya chpn dp dyng mot s l gidi cd t h i disac diing lam phuong tien rieng d l tao phdp chu ylu sau: on djnh hogc ehung sir dyng phli hgp vdi cdc Gia cudng khdi dd bdng be tong phun dang gia c l khdc nhu be tdng phun, xd thep, kit Be tdng phun dugc su- dyng rpng rai d l nang c l u giu bdng be tdng cap I n djnh cdc bd doc, tudng cdc h i ddo sdu Cdc kilu phd hoai chinh phai k l d i n vd cac cdng trinh nglm mdi doc vd cdt da dugc the hign tren hinh Cac Bd tdng phun sir dyng chu y l u d l tdng mu-c eo c h l sau day cd t h i dugc ghi nhgn, don le dp on d^nh cho cdc mat Ip dd, be mat dd nirt ne hoae phoi hgp: nlu khdng dugc xir ly b l mgt 10 dd ed t h i bj hu - Pha hogi theo mat tilp xiic dd ylu; hgi dudi ede dieu kign biln d l i udt vd khd - Phd hogi djnh trudc dgc theo mgt hogc KHCNM S 2/2015* DIA CO MO Thong tin khoa hpc cong nghe m d Phan IIJC phdp tuyfr W = Trpng lupng kh6i a) Trt/gf diy hoic cic mit phing lOp; b) Tnfot trin cic khe nOt; c) Trupt trin chd dui doan hoic cic mit phing nghlOng; d) Lit; e) Ndm phi ho$i; Hinh Cic kliu phi ho^i nguyin tic mii ddc vi chd cit di nhilu khe nirt; - Phd hogi kilu nem dgc theo cae khe nirt giao nhau; - Phd hogi dpc theo cdc c h l phan each yeu cdc viing cat hogc be mat phd hogi cd tip trudc; - Pha hogi Igt dd cd cdc khe nirt an sau Phdn tich khli dd hoac nhO'ng viing cd khd nang khdng I n djnh cd t h i thuc hien bang cdch xem xet cdc lye ngodi tdc dgng tren khoi vd cdc vung don diing phdp phdn tich dOng hgc don Cong thOv cho d^ siu cdn Mdt neo Tuyin nhiiu neo Lo^i da Di khflng dong nhit •^1^4.441 Bd niPt ne kh6ng theo quy ludt oa nirt ne bj ngdp kh6ng theo quy lu$t Hinh Phin tich dan giin dn dinh ciJa cic mii dOc di gian (hinh 2), De chl ddn, sau cua neo ed t h i dugc xdc djnh bing cdch diing cdc thdng so thich hgp cdng thCyc cua bang Trong dd: T - Dg bin ehju eat eua da, kN/m^; St - Hg so an todn ve phd hoai (trong thyc t l diing gid trj tip 2-5-3), s - Khoang cdch gitra cae neo, m; O' - Gde ma sdt cd hieu qua di qua eae cho nirt gay khoi dd, dp; Tw- Tdi trpng lam vigc tren neo, kN; Y - Trpng lugng don vi cua dd, kN/m^; yw - Trpng lugng don vj eua nude, kN/m^ Kinh nghi$m thuc t l vdi cdc neo nghieng hudng xuIng dd cho thiy, phd hogi ehung cCing vdi b l mgt lop tren khdng xay d l i vdi t j s l dp manh (h/D) vugt qua 15, (h Id dg sau tinh d i n dinh cua bau neo va D la dudng kinh cua %m't •1 "'""• iW-r.W*) KMCNM 2/2015* D|A CO MO C/Jliy 2.830 vl?^J vlo-j-.wvj Si2+4: GSc dinh bSng 90° (gia thik) Thong tin khoa hoc cong nghe mo (a) Ki^u A CO bio v$ neo cd djnh (b) Kilu (c) tGiu C (d) Kilu D Cic kliu neo phun vQ'a xl ming Hinh Neo diin hinh di, khdng dinh bim trdn sudt chidu dii diy neo ti/ blu neo) Ooi vdi cae neo manh (h/D>15) co che pha hogi da cd xu hudng cue bg d viing blu neo Da nirt ne bj ngdp khdng theo quy luat Hi$n d l gia co cae mdi doe, bd md ngudi ta dp dyng phi biln hai logi neo' Neo be tdng cot thep vd neo chat deo c l t thep Tinh chat co ban cua chiing dugc t h i hign tren hinh Khi sudn ting dugc cau tgo bdi cdc khoi da phan Idp cdm vao khdng gian khai thdc vdl gdc nghieng p = 20•^50° [3], d l dam I n dinh eho cdc cdc tang cat gdc doc sudn tang Idn hon gdc nghieng cua Idp at > p, ed the ap dung giai phap gia cudng sudn tang bang cpe neo be tdng elt thdp, so b l tri cac cgc neo tren tang diyoc gidi thi§u tren hinh SODOBOTRIC.^CI-W Trong trudng hgp ndy, cdc cgc neo can dugc ddt sau hgn mgt trugt thir d p (cdc mat yeu) ting tip 3-H5m Sire ehju tai cua cgc neo vd cdc thdng so neo theo Iln lugt duge tinh todn xdc djnh theo cdc c6ng thirc: - Sire ehju tdi cua epc neo Q: Q = RaFa + RbFb, T; (1) Trong dd: Ra - Khdng lue cat tinh todn cua cot thep, kG/em^; Fa - Dign tich mat cdt cua cot thep, em^; Rb - Khdng lye cat cua be tdng, kG/cm^, Fb - Dien tich mat cat cua cpe be tdng, cm^; - So lugng epc neo theo mat cat: "=-; (2) Trong dd: AT - Lye gay truot eua khoi dd, T; Q - Sire ehju tdi eua epc, T; L - Chieu dai eua mgt y l u , m; D l i vdi bd try Nam, md than Deo Nai, de dam bao on dvnh eho sudn tang bang phuong phdp neo bang cgc be tdng c l t thep, cac thdng so neo duge xdc djnh nhu sau: - Dudng kinh lo khoan neo: DK = 230mm; Hinh So dd bd tr! h$ thdng cic cgc neo bO tdng - Dudng kinh epc neo: DN = 200mm (tilt dign cdt thip gia ci/Ong suxyn ting kdt thuc trdn hoac vudng); KHCNM s d 2/2015* DIA CO MO Thong tin khoa hoc cong nghe m d - Chieu ddi neo: Li = 14m; L2 = 8m; - Khoang cdch giii'a eae epc neo tren mat tang = 7m; - Khodng each tir mep tang d i n hang neo thir nhat: 3m; - Khoang each gCra eae hang neo: az = 5m Doi vdi cdc bd md Ip thien Viet Nam, giai phdp ndng cao on djnh bang neo ehua dugc dp dyng chi phi Idn vd thi edng phirc tgp Phu'cng phdp d i l u khiln I n djnh Dam bdo dp on ^nh cho cdc bd md qua trinh md rpng vd ddo sdu cde md lg thien bang giai phdp dieu khien tire Id sir dyng cde gidi phdp cdng nghg d l dieu chfnh trgng thdi vd cdc thdng s l hinh hgc cua bd md tirng giai dogn khai thdc cy thi, dam bao cho bd md ludn on djnh duge eau tao bdi eae idp ddt dd cam vdo khdng gian khai thdc vdi gdc d i e p > 20°, c l n cat gde doc sudn tang bang gdc doe mat Idp (a = p) Trinh ty dp dyng giai phap dilu khiln SLP dyng edng nghe khai thde d\xqc thyc hign theo tuan ty sau: - Bang thye nghi$m, xdc djnh t i e dp biln dang gidi han cho phep (Vgh) cho tirng khu vyc bd md cy the - Thilt ke bd md cdt tang vdo tm vdi hg so dy tru on djnh n = 1,11 - Tiln hdnh lap cdc tuyln quan trie djch dgng vd quan trac (^nh k>f, xac djnh tie dp djch chuyin cua bd V - Khi t i c dg djch ehuyin V > 10mm/ngdy dem vdo miia khd vd > 20 mm/ngdy dem vgo miia mua, kilm tra Igi dp I n djnh cua bd md Neu hd so on djnh tinh todn cua bd n < 1,05 ein dilu chfnh ede thdng so hinh hpe cua tang bang cdch md rpng chieu rdng mat tang, giam chieu cao ciia ting Tiln hdnh kiem tra dO I n djnh eua todn bd, dua bd ve trgng thdi I n djnh vdi hg s l dy tru'n = 1,10 Trong qud trinh thilt ke khai thdc, c l n ldm rd cdc khu vye ed t h i bj biln dgng can cu vdo sy cd mgt cdc Idp dat dd ylu, cde mat y l u ty nhien nhu mat Idp, phan Idp, mat pha huy elm vao khdng gian khai thac Trong qua trinh khai thde, trinh ty khai thde c l n tinh tdi cdc khu vyc Cde hao md vfa c l n duge dat viing dat da I n djnh Trong dilu kign cho phep cde viing cd Ap dyng giai phap dilu khien on dinh bd mo c l u trOe mlm yeu nen dua vdo khai thac sau qua trinh khai thdc cho phep hodn todn chu ciing de dam bao thdi gian ton tgi Id ngan nhat dpng dieu khiln qud trinh biln dang cua bd dam Trinh ty khai thdc can dugc lya chgn cho bdo khdng nhO'ng an todn eho qud trinh khai bd c6 djnh khdng edt chdn cde Idp dd cam vao thac xuong sau ma edn cho phep giam din mirc khdng gian khai thde, tao gde doe sudn tang it nhat khli lugng dat bde xir 1;^ ngoai gidi hgn theo gde die mat Idp vdi chilu cao gidi hgn on ting giai doan khai thac xuIng sdu cua mo djnh cho tirng khu vuc cy the LiKa chpn giai phdp dam bao I n djnh Trong khu vye ylu, c l n tang eudng dp khai cho bd tru Nam thac d l dam bdo kit thiic khai thde bat diu Can cir vdo thilt ke khai thde vd nguyen nhan xay pha biln dgng tieh cue mdi (nhu cudng dg djch ehuyin tuyen edng tdc, t i e dp xuong trugt Id tgi bd try Nam, bd try se khdng dam bao sau ) Khi edng tdc md tiln g i n tdi bien gidi kit on djnh tien hdnh khai thdc bdm try lien tyc thiic bd dirng tgm thdi, nlu dieu kidn eho phep den kit thuc -330m theo thilt k l (chilu cao bd thi khai thde theo Idp ngang va n l tap bien md 450^80m; a = p = 25^33°) bang cac Id khoan nghieng Vdi c l u tn^c dia tang cua bd try Nam cho Trong thyc t l khai thdc, nhilu khdng the phep xem xet dp dyng gidi phdp gia eudng khli dipng dugc qud trinh khai thae, ma can phai khai dd bdng neo be tdng e l t thep, neo irng suit thdc viing bj bien dgng, vdi toe dp biln trudc bing neo, day neo hay neo chit dgng chua vugt qud toe dp biin dang gidi han, deo; han che eua giai phdp Id chilu sdu neo dd, vigc khai thae can dugc tiln hanh vdi bi hgn che Hien nay, phin Idn cdc logi neo dugc thilt bj boe xuc cd tinh eg ddng cao, nhu may che tao cd chilu dai khdng qud 10m Vige dp dung giai phap neo dk gia cudng khli dd theo xiic thuy lye g i u ngugc, mdy xiic tai Vdi cac bd md cd ehilu cao Idn hon 200m va mat Idp gap phai nhimg hgn che sau: Chilu sau mat trugt tir 30+50m bi pha huy trugt Id vdi KIIC\iMSO2/20l5*D!ACa.M6 Thong tin khoa hoc cong nghe md chieu cao tip SO^ISOm, khdng dam bao an todn vdi phugng dn XLP ly duge thilt ke, dg dn tSnh cho qua trinh thi cdng Do vay, giai phdp neo d l i eua bd tru Nam dugc dam bao vdi he s l on ^nh vdi bd tn,! Nam chl cho phep xem xet kit hgp vdi n>1,10 giai phdp hg thip gdc d i e cua bd d nh&ng khu Ve mat kinh t l , kinh phi thyc hign ciia vyc xay bien dang thir c i p vdi chieu ddy khoi phuong dn XLP ly Id 458 ty dong, phuong dn trugt nhd hon 5m de ehong lai qua trinh bong x\> ly Id 487 ty dong, do, ve hieu qua kinh Idp va sir dyng epc neo be tdng cdt thep tien t l , kinh phi xCr ly on djnh cua bd try Nam theo hdnh cat ting bd try d giai doan kit thiic phuong an XLP ly Idn hon phuong dn xu ly 11d Gidi phap dilu khien on djnh bdng cdng nghe 29 ty ddng khai thdc doi vdi bd tru Nam Id tinh todn dilu Tip cdc tinh todn thu dugc cho thay, phuong khiln cae thdng so hinh hpe eua bd, dua bd v l an XLP ly dam bao on djnh cho bd try Nam khai trgng thai on djnh mdi, vgy, giai phdp ndy thdc din kit thuc ddy md d mire -330m bdng eat thudng dugc dp dyng phli hgp vdi giai phdp hg tang vdo try (phuong an XLP ly 1) khdng ehf toi thip gdc doc eua bd uu v l mat kinh t l - ky thugt md cdng tdc thi cdng Kit qua nghien ciru cho thay, bd try Nam, md cho phep sip dyng toi da cdng nghe khai thac Deo Nai hien dang d trgng thai I n djnh hien md dang dp dung Ket qua thir nghiem gidi han (n = 0,983) Qua trinh khai thdc xuong xip ly cdng nghg cat tang vdo try dugc thyc hign sdu din kit thuc -330m theo thilt k l bam tn^ lien tgi khu vyc tai bd try Nam ndm 2014 da tyc (a = p) bd try Nam cd chilu eao tip xae nhdn tinh kha thi cua giai phap XLP ly dugc 450-^480m, khdng on djnh (hg so on dinh n = lua chgn 0,68-^0,85) K i t lugn Vdi eo c h l trugt Id xay tgi bd tm Nam, Dk dam bao on djnh cho bd try Nam, md than theo cae kit qua nghien ciru da dugc thye hien, Deo Nai, qud trinh khai thae xuong sdu din giai phap xu ly duge kiln nghj ap dyng la cat kit thiic theo thilt k l (-330m), giai phap xiy ly ting vao try vdi cac thdng so ting duge xdc djnh dugc lya chgn Id giam gdc doe cua bd bdng nhu sau: bign phap edt tang vdo try vdi gdc doe sudn ting Chieu cao tang: ht = 80-^150m; bdng gdc doc mgt Idp (a = p) Gdc doc sudn ting: at = p = 25-5-33°; Trong qud trinh khai thde xuIng sau tiln hdnh Chilu rgng mat ting: bt = 20^25m quan trie djeh ddng kit hgp tinh todn dieu khien Uu diem cua giai phap la dam bao on hg so on djnh eua bd theo tirng ehdng xuIng sau djnh cho bd md ( n = 1,145); qua trinh thi cdng 50m vdi he so I n ^nh n =1,1, cho phep dam bdo su* dyng cac thilt bj khai thac cua md va an toan eho qud trinh khai thac vd gidm khoi cae dang cdng nghg khoan n l min, bic xiic van lugng dat bdc xie ly d i n mirc thap nhit tgi bd tnj tai dang duge sip dyng se eho nang suit vd higu Nam, md than Deo Nai./ qua cao Qud trinh XLP ly dugc thyc hien theo Tai lieu tham khao: trinh ty khai thac xuong sdu da duge thilt k l , Bdo cdo kit qua {^990y'Nghien cO-u on vgy, qua trinh xu ly, ed t h i theo doi qua trinh on djnh cua bd d l dieu khien cho phep dinh bo mo IQ thien Vi$t Nam va kidn nghi cic glai phap nang cao Sn dinh bo mo", Vien Nghien giam khli lugng theo tinh toan ciru Khoa hpe Ky thugt Md - Hd Npl, 2003 D I SO sanh higu qua kinh t l ky thugt cua giai Bdo edo tong kit d l tdi "Nghien cCru bien phap dugc lya chgn, tiln hanh tinh toan so sanh gidl phap dieu khien I n djnh bang phugng phap dang ba mo va cac bien phap dam bao on dinh clt ting vdo try theo cdc thdng sd thilt k l da bo mo 16 thien a cac mo: Deo Nai, CQC Sau, Ha dir(yc xdc djnh tren todn bd md {phuong an XCF Tu, Na Duong, Nui Beo va Cao Son" Vien khoa iy 1) vdi giai phdp neo bdng epc be tdng cot thep hpe Cdng nghe Md, Hd Npi, B.P Beliaeb 1973"Gdn ket dat da', Nhd kit hgp cat ting tir eao trinh - 200 den -100m (phugng dn xCr ly 2) Kit qua tinh todn eho thiy, xuat ban Nhetdra - Matscova KHCNM s o 2/2015* DJA CO MO ... i t lugn Vdi eo c h l trugt Id xay tgi bd tm Nam, Dk dam bao on djnh cho bd try Nam, md than theo cae kit qua nghien ciru da dugc thye hien, Deo Nai, qud trinh khai thae xuong sdu din giai phap... kinh t l - ky thugt md cdng tdc thi cdng Kit qua nghien ciru cho thay, bd try Nam, md cho phep sip dyng toi da cdng nghe khai thac Deo Nai hien dang d trgng thai I n djnh hien md dang dp dung Ket... phugng dn XLP ly duge thilt ke, dg dn tSnh cho qua trinh thi cdng Do vay, giai phdp neo d l i eua bd tru Nam dugc dam bao vdi he s l on ^nh vdi bd tn,! Nam chl cho phep xem xet kit hgp vdi n>1,10 giai