Ky niem 43 nam thanh lap Vien Khoa hoc Cong nghe Mo - Vinacomin
I/NGH!EN,CUU AP DUNG KET CAU KET HOP SUT DUNG NEO VA NEO CAP NHAM NANG CAO HIEU QUA CHONG GIUTCONG TRINH NGAM
Active support structure with using reinforced anchors and cable anchors has many dominant advantages. However, during its application, it is necessary to have some control methods for increasing its supporting efficiency and then, as a result, for orientating the support design and selecting the reasonable output and input parameters to increase the mutual assistance between reinforced anchois end cable anchors. The paper refers to some methods in the coordinate uWization of anchors and cable anchors for increasing the supporting efficiency at underground constructions and mine dnfts
TS. TRINH eANG HUNG KS. PHI VAN LONG KS. NGUYEN VAN CONG KS. HOANG PHUONG THAO Vi$n Khoa hoc Cdng ngh$ Md - Vinacomin
Bien tip: TS. Truxmg Dtrc Dif
LDatvdndl
Vgi nhung uu diem ca v l kha nang ching giu, an todn, gid thdnh hp cung nhu phpm vi dp dung, tLP Idu, k i t c l u chong Id bang vi neo da dugc O-ng dung rpng rdi trong vipc ching giu cac cdng trinh nglm, dudng Id md tren t h i gidi vd g Vi^t Nam. Trong qua trinh phdt triln, da cd r i t nhilu k i t c l u neo dugc siJ' dgng trong thg'C t l . Theo cc ehe chju tai, ngudi ta chia ra neo ma sdt, (neo nem che, neo Ing, ...), neo dinh k i t (neo be tdng cot thep (BTCT), chit deo c i t thep (CDCT), neo cdp,...).
Trudc day, nhung loai k i t eau neo nay thudng dugc su dgng dpc lpp, tuy nhien, qua thyc t l dp dgng cho thay, vipc su dgng mpt logi neo ehua phdt huy dugc toi da nhung uu diem cua k i t c l u chong neo. Vi dg, khi ching giij" cdc Id dpc via chiu anh hudng cua dp Ig'C Id chg, hope cdc nga ba, ngd tu, khiu dp chong gii> Idn, n l u chi' su dgng den thuin neo BTCT hope neo CDCT, se khdng dam bao an todn. Trong trudng hgp ndy, n l u su dgng neo cdp se giai quylt dugc bdi toan v l kha nang chong giu, tuy nhi^n, gid thanh ching Id se tang.
Hipn nay, a cdc nudc tidn t i l n trdn t h i gidi, ngudi ta dd dua vdo dp dgng h0 k i t c l u ching giu cdc edng trinh ngam cung nhu dudng Id md, vdi vi$c k i t hgp neo vd nee cdp. Ket c l u ndy khdng nhQ'ng phdt huy dugc toi da uu diem cua tung Iopi neo, dam bao kha nang ching giu on djnh, an todn, md cdn giam gid thdnh ddo ching Id.
Bdi bdo ndu ra mOt s l phugng phdp k i t hgp su dgng neo vd neo cdp nhim ndng cao hipu
qua chong giu cdng trinh ngam eung nhu cdc dudng Id trong cde md h i m Id.
2. Nguyen ly k^t hp'p neo cdp vd neo cdt thep trong vipc chdng g i u cdng trinh n g l m
Neo cot thep (BTCT, CDCT) va neo cdp d i u la k i t c l u chong chu dpng, chju Ig'C theo cc c l u bam dinh. Trong dd, neo cot thep cd chipc nang chu yeu Id lien k i t cac Icp da tao thdnh ban dam phia tren ndc Id, hgn che kha nang "freo" ching da ndc tach khoi nguyen khoi. Doi vci neo cdp, dgc diem cc ban la chilu dai len, chu'c nang chinh Id "treo" da ndc len Icp vach cc ban. Tu do, trong h$ k i t cau ndy, neo cdp cd the tgo ra dugc dy ung Ig-c cao va nang Ig-c nhdn tai len, cdn hp thong neo cot thep xung quanh hinh thdnh ban dam vd dugc neo cap "treo" len vdch cc ban. Nhu vdy, k i t c l u ndy sg hinh thdnh dam t l hgp, bao vp da vach, han c h l djch dpng, ngan ngOa sy phdt trien cua vdm sgp Ic, khien cho lyc tdc dgng cua neo cdp vd neo cdt th6p lan can tucng hd cdng hucng, t l hgp hinh thanh len mpt dam da mdi, vci do day do cung, cucng dp khdng cat cua d i m da nay tang len, ap luc ndc Id thong qua trg bao ve chuyin djch vdo sau bdn trong. Thdng qua do, cai thien dilu ki0n chju lyc cua ducng Id, khing c h l hipu qua su djch chuyin cua dat da ndc va hdng Id.
So sdnh vci neo cot thep, thi neo cdp ed dp sau gia co va lye gia co len, cd the tao dy ung lyc khd Idn vd hang logt nhung yu diem khdc, ta mpt trpng nhung ky thugt quan trpng khdng t h i thilu trong gia co cac cdng trinh nglm cd d i l u kipn khd khdn phi>c tgp. Neo cdp cd cdc logi khdc nhau, nhu neo cdp dy ung lyc d i u
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neo. neo cdp dy yng lyc todn thdn, neo cdp phi dy Cmg lye todn thdn ... neo cdp vdi hinh thCre khde nhau thi co che gia co chdng giy cung khac nhau. Trong dd. neo cdp dy ijng lyc dau neo dugc sy dyng r^t pho bie'n. Log! neo ndy chu y l u Id tdc dgng treo. Neo cdp mang Idp d i t dd khdng on djnh Idp dydi treo vdo Idp d i t dd dn djnh d phia tren. Ddng thdi, do neo cdp cd t h i tgo ra dy yng lyc khd Idn, ed t h i keo cang vd dp chat cdc Idp dd, khe mit, nhijng mat khdng lien tgc, Idm tang len lyc ma sal giOa cde mat Idp, tip dd, nang cao cydng dd tong the khdi da.
Neo edt thep vd neo cap khdng phai ch? don gian Id tdc dgng ehdng giy k i t hop gia eydng md con Id ehdng giy tyong hS i l y ddi b l trg ngin, dac tinh cua hd 'ket cau chong-khdl di'vi die tinh eo hgc eua hd "neo cdt thep - neo cip"
ed sy kit hop. Trong dilu kidn dit da mdm y l u bd rdi, dit dd xung guanh dydng Id biln dang Idn, sau khi khai ddo ldp tCrc sy dyng neo cap, cd t h i do dd ddn ddi cua neo cap bi vygt gud gidi han md dan toi phd huy. Do dd, d giai doan diu, ddo Id th] ehi ldp dgt neo ed't thep, thdng gua tdc dgng gia cd eOa neo edt thep ma hg kit c l u chdng-khdi dd da cd khd nang chju tdi nhit djnh, eho phdp phdt sinh biln dang, gidi phdng mdt phin biln dang trong khdi dd, d i t da trong pham vi biln dgng nhit djnh cd t h i giO gin t y thdn dn dinh[3i. Tuy vdo mye dg bien dgng eua d i t dd xung guanh md tdng Idn, khd ndng chju tai vd dg dn dinh cua hg "kit ciu chdng-khdi di" giam di, trydc khi tinh t y I n djnh cua hg "kit ciu chdng- khdi di" dat d i n gidi han, khi biln dgng dy cua dit da nhd bing dg dan ddi eho phep cIJa neo cdp, liic ndy tiln hdnh ldp dgt neo cdp se Idm giam nhd ydu clu v l dg ddn ddi cua neo cdp ddi vdi dit dd, bdo dam giO eho hg "kit ciu chSng- khii ifd"dn dinh (hinh 1 b). Thdng gua hd neo cot thdp k i t hgp neo cdp, se ndng eao dygc lye chdng giCf, giam biln dang eua d i t dd. Neo kit hop neo cdp phdt huy uu t h i I l n nhau, dydng Id d giai dogn ddu khai ddo thi tinh deo cua neo thydng se dygc phdt huy, d i n giai dogn sau khai ddo thi tdc dgng treo cua neo cdp se dygc phdt huy hai tinh chit ndy tyong ho bd trg oho nhau, Ily ddi bd trg ngin, t y dg, md eai thidn tinh ndng ehing giy tdng t h i cua hg thdng, dgt dygc mgc dieh khdng c h l sg- biln dgng Idn eua dat dd Do dd. tdc dgng ching giir ndy cd t h i ggi Id
tdc dung chdng giy tyong hd bo trg neo kit hgp neo cap. Thdng gua tdc dgng ndy Idm tdng len tinh on tfinh vd khdng c h l s y phdt trien nCrt ne trong khdi dd xung quanh. bao dam an todn trong san xuit.
3. Nghien CLPU hodn thien k i t edu chdng giu* cdng trinh n g l m k i t hQ'p neo vd neo cdp Chong giO' dyong lo la khdng c h l dat dd xung quanh biln dgng va duy tri bao vd dydng 16.
Trong trydng hop chung. ngodi cdc ylu td dia ky thudt. qud trinh hinh thdnh tdi tnpng tae dgng Idn k i t c l u chdng giy cdn chju sy anh hydng rit Idn cua mdt logt cac y l u td nhy; thdi diem ldp dyng kit eiu chong; dd cung cua kit clu chong;
do linh hogt cua k i t c l u ehdng. vd nhOng y l u t i khdc[2i. Xu t h i hign nay Id sO dung kit clu ehdng giy chii dgng (tang khd ndng mang tai ciia khdi dd bao quanh cdng trinh nglm. coi bd ph^n chju tdi chlnh la khdi dd. tao thdnh hg vd ehdng- khli dd nhy neo, bd tdng phun, bom ep vu'a gia eydng...). Chdng giQ" bdng neo cd higu qua khdng c h l dygc b i l n dang cua d i t dd bao quanh hay khdng, ehii y l u la d logi hinh kit cau neo vd cdc tham s l chong giy dd hgp ly hay chya. Trong dieu kign d i t da nhit dmh, mgt do neo. dydng kinh neo, chieu ddi neo. do ddi gia cd cua neo md tang Idn. thi biln dang eua dit dd bao quanh dydng Id se gidm d mye dg khdc nhau. Trong qud trinh thilt k l . eIn tong hgp xem xet gid thdnh chong giu' vd higu qua chdng giiJ.
ddp yng ydu c l u Idn nhit d ca hai phyong dign ky thugt vd kinh t l .
3.1. Phin tich sv sip Id cue bd xiy ra khi chdng bang neo cdt thep ket hap neo cap
Thyc td' tai mgt so dydng Id chdng bing neo k i t hgp neo cdp da xdy ra sy phd huy cgc bp.
Od eao Id ndc eua dydng Id Idn hon dg sdu gia e l cua neo thydng. nhyng nhd hon dg sdu gia c i eiia neo cdp. Sau khi Id ndc. dgi da sd neo cdp bi dirt, dogn gia c i neo cdp vdn lyu trong khii dd cdn Igi d trdn ndc. cdn todn bd neo thydng bj roi xudng. than neo thydng vd phg kidn van tit. Nguydn nhan ehu y l u Id ndc Id:
Trong qud trinh ddo Id. I l p d§t neo vd neo cdp cdng vdi thi edng Id chg, md men d y Cmg lyc khi i l p dgt neo Id lOON.m, sinh ra dy i>ng lyc rit nhd (10 - 15kN). khdng ed tdc dyng ching giO chu ddng. khdng t h i khing c h l hidu qua dit da
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b i l n dgng thdi ky d i u . Nhyng d y yng lyc eiia neo cdp r i t cao (khoang 80kN). d i n tdi tai trgng thdi k^ d i u ching glQ' t$p trung vdo neo cdp. cdn neo cot thep mat dl tdc dgng chu dao chju tdi.
Trong qud trinh ddo Id. biln dang elp tdc cua d i t dd. neo va neo cap d i u bj keo dan. ddng thdi lyc kdo cung tdng len. Nhyng do dan ddi cua neo cdp r i t thip. dd dan ddi eua neo thydng r i t cao.
dd biln dgng eiia 2 logi chenh Igeh Idn, khdng thich ling vdi kha ndng bien dgng eua d i t dd, trong ca qud trinh ching giy khdng the ddng bd chju tdi. khdng hinh thanh hop lyc idm t i c dd tdng tro lyc len neo cdp qua nhanh. khi lye keo cila nd vygt qud gidi hgn se bj dCrt cdp. d i n tdi sgp td ndc Id ma neo thydng v i n khdng t i n hgi gl. Cho ndn. trong ehing giy k i t hop neo cot thep vd neo cdp. dgt dygc hieu qua ching giir ly tyong c i n phai phii hop ian nhau kha nang biln dang cua ca hai logi [4].
3.2. Didu chinh ket du sal thdp, ning cao dd dan dai cOa nd trong neo cip
Lyc keo dyt cdp vd kdt c^u sol cdp thdp cua neo cdp ddng vai trd rd't quan trgng. Neo cdp khi Ilp dgt. se tgo ra mdt dy Crng lyc can thiet. Trong cdp se xuit hien lyc cdng T. Trong pham vl biln dgng dan h i i quan hd giya T vd dd dan ddi cua cdp Al Id ty ig bac nhit. Cdp dang d trang thdi t y do, khi gap tryong hop d^t dd biln dgng kjch ligt, cdp cd the' se bj dan ddi, vygt qud gid th gidi hgn, khi dd lyc cang trong cdp T > T] [T] -Lyc kdo dCrt gidi han cua cdp). S y gidn edng ndy phg
thudc vdo tCrng logi cap, cdng nghd c h l tao, tieu chuin san xuit... Dg dan dai cua sgi thep neo cdp va k i t c l u cua nd cd m i i quan hg r i t Idn, thing thydng. neo cdp van hay sy dgng cdp 1x7 dg dan ddi chi Id khoang 3,5%. thich Crng vdi kha ndng biln dgng cua d i t dd, nhyng rit khd thich Crng cung vdi neo eha't deo cdt thdp. Ngdy nay.
logi cdp mdi c h i tgo. quy each sgi cap thep Id 1x19, ed nhieu sgi hon, rdt yu vigt ddi vdi ket c l u cdp thep kieu soi, dg day ddc cua k i t c l u t i n g t h i vygt xa mat dg k i t c l u cdp thep 1x7.
ndng cao dp on djnh, vCra bao dam dd cCrng vya lam tang he s i tinh mem cua cap. bdo dam gian tien thao tdc tgi hign trydng, dd dan ddi khdng nhd hon 7%. ndng cao thich Crng kha nang biln dgng kich lidt eua d i t dd ndc Id.
3.3. Phdi hap diiu chinh lech thdi gian thi cdng neo vi neo cap
Quan hg tdc dgng tyong hd cua he ehing giy-khii da dygc thd' hidn nhy trong hinh 1.
Dydng dgc tinh co hgc cua neo cdp (4) vd dydng dde tinh eCia he "ket cau chdng-khdi di"
(3). vd dydng dac tinh co hgc cua k i t c l u ching giQ-thdng thydng Id khdng gidng nhau, nang lyc nhan tai cua he k i t c l u ching-khii da Id tiiy vdo biln dang tang Idn thi khd nang chju tai se giam di. Dydng cong 11d dydng ddc tinh khii dd, bleu thi m i l quan hd giya eydng dd ching giy va bien dgng d i t dd. Dya vdo nhyng phdn tieh trdn, n l u dydng dgc tinh cua he k i t e i u ching giy - khii dd vd dydng dac tinh cua neo cap khdng
jBien dang cua dat da|
|)i£n d ^ R cua ddt da|
1. Budng die tinh dit di: 2. Dudng die tinh ching giO kit hap neo vi neo dp Uo - Dich chuyin hi mit dudng Id: 3. Budng die tinh cOa hi kit eiu ehing - khdi di AL -Bddin dii cua neo dp:
4. Budng die tinh neo cip
Hinh 1. Quan hi tie dung tuong hi kit ciu ching vi dit di
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^^^^^Hmh^Hinh 'inh'neo cip' t h i cung vdi dydng eong 1 giao cat nhau dilu dd eho thiy. ddc l^p su' dgng neo cdt thep hodc die ldp sO dung neo cdp d i u khdng the khing c h l dit dd dat dygc i n djnh. N l u ehing giy neo c i t thep vd neo cdp k i t hop, dydng dgc tinh edng tdc dgng ehing giy 2 vd dydng eong 1 giao nhau, bilu thi ehing giu k i t hop neo cot thep vd neo cdp da nang cao kha ndng chiu tai cua hd k i t c l u ehing, tgi dilm giao elt, biln dgng cua dit dd dgt dygc sy khing c h l . bao dam duy tri dg i n dinh eiia dat dd xung quanh dudng Id [4] Nhy vdy se ed hai trudng hop:
- Trong tm'dng hop khi neo vd neo cdp ddng thdi dygc Ilp d^t (hinh la), bdo dam tiln d l thdnh edng ehing giu' neo k i t hop neo cdp la khi d i t dd xung quanh dat dygc 6n djnh d i biin dang Uo nhd hon dg ddn ddi gldl hgn eOa neo cdp. Thda mdn dilu kien tinh i n djnh eua dat dd thi trong trydng hop ndy ndi ehung Id khd tdt. khi dd cd t h i thdng qua lya chon hgp ly ede thdng s i vd quy cdch neo d l sir dung neo ddc Igp ed t h i bdo dam duy tri dd i n djnh eua d i t dd.
- Trang tnfdng hgp dydng Id qua d i t dd mIm ylu vd ndc Id rdi vgn. mCre dd biln dang Idn. giai dogn d i u khai ddo dydng Id tiln hdnh ehing giCr bing neo cot thep, chu y l u dya vdo tinh mIm eiia neo cdt thep, md giai doan sau khai ddo mdi phdt huy tdc dgng treo ciia neo cdp. Cd nghTa Id,
neo cdp se dygc ldp dgt sau, khi dd, neo c6t thep vd neo cdp khdng d i n g thdi cCing tdc dgng gia eydng, ma Id tyong hS. lay ddi b i trg ngan, tCr dd eai thign dygc r i t nhilu tinh ndng ching giQ' ting the hd thing ehing neo, thyc hign dygc tdc dgng khing c h l d i t dd biln dgng. Nguyen ly tdc dung tuong ho chong giO nglu hgp lan 2, neo cap lap dgt sau neo cdt the'p (hinh lb).
Trong cdc dydng Id dgc via phdn tang sau ktii khai ddo, t i e dd bien dgng cua d i t dd khong ngyng thay ddi, thydng trai qua 3 giai doan: giai dogn anh hydng cua qud trinh dao Id, giai dogn on iflnh vd giai doan anh hydng cua hogt ddng khai thde. Giai dogn anh hydng ciia dao Id trydng Crng suit nguyen sinh phdn bd Igi, tic dO bien dgng nhanh, ydu c l u ddi hdi neo edt thep vd neo cdp cd do dan ddi khd Idn d l thich ling vdi biln dgng d i t dd, eho ndn, trong thyc t l thi cdng, cung vdi viec thi cdng gyong Id ehg, ndn c i n tgo ra cho neo cdt thep m i t dy yng lyc kha cao, khdng c h l biln dgng sdm cOa dit dd. C6n- neo cdp th) nen thi cdng lap dgt sau neo cdt thep, khi biln dang e l p tdc chuyin sang biln dgng ehgm d i n , khi dd Id giai doan t i t nhit dd Ilp d|it neo cap.
3.4. Phdi hap thuc hiin diiu chlnh dd Idn du ung tuc neo va neo cip
Trong ehing giO k i t hop neo edt thdp vd neo cdp, neo cdt thep khing c h l bien dgng vd tacli Idp dit dd ndc trong phgm vi gia c i ciia nd, tuy vdo biln dgng vd tdch Idp dd't da' ndc Id tdng len, neo bj dan ddi, neo a trong qud trinh kdo dan, lye kdo cung tang Idn. kha nang khing chl liiln dang d i t da eung tdng len. Do phgm vi gia c6 cua neo cdp bao hdm phgm vi gia c i cua neo cdt thep, eho ndn neo edt thep d trong qud trinh kdo dan. thi neo cdp cung bj kdo ddn. Trong qud trinh thi edng thyc t l . nen tgo d y lyc khd Idn eho neo cdt thep, giam thd'p nhat biln dgng vd tdch idp cua d i t dd. neo cap nen tgo d y Crng lyc nhd. d l do biln dgng vdn cdn d y trong neo cdp. d l thich Crng vdl biln dang va tdch Idp giai dogn sau ciia d i t dd I"'. Cdng thCrc suy ludn dilu kidn phii hgp kha nang bien dgng neo cdt thep va neo cdp nhi/
sau:
Khi khing d y Crng lyc:
Pamax ~ K « Aimax Pgmax = Kfl Z^gmax
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K=' nYld'a^,
Khi ed d y ung lyc:
Psmax = Pso + K s A s Pgmax — Pgo + K g A g
Bat tudn cd hay khdng cd d y ung lye, gid tri K d i u Id khdng thay d l i , do dd d i l u kipn phii hgp khd nang biln dgng Id As=Ag, tuc la
dl<^..lA Trong dd:
Psmax, Pgmax - Khd ndng chiu tai gici hgn cua neo cdp vd neo cot thdp; Ks, Kg - H# s l nh^n lyc neo cdp vd neo cot thdp; Asmax, Agmax- Bq dan ddi gidi hgn cua neo cdp va neo cot thep; ds - 0 u c n g kinh sgi cdp thep neo cap; n- So sgi thep neo cdp; dg -Ducng kinh neo cot thep; 5bs, 5bg- Cudng dp gidi hgn v^t Ii$u neo c6t thep vd neo cdp; U, Ig - Chilu ddi nep cap vd neo cot thep;
5s, 5g- Dp dan ddi cua neo cdp va neo cot th6p;
Pso,Pgo - Dy ung lyc neo cdp vd neo cdt thep.
Ndng cao dO b i n cua hp neo cot thep ket hgp neo cdp d l i vci hipu qua chong giu rat quan trpng, d y i>ng lyc eua npo ed tdc dgng quylt djnh, gay ra cho neo mpt d y ung lyc khd len, d i n g thci, thdng qua t i m dpm, thanh nep vd nhCmg c l u ki^n khdc, thyc hipn l^uech tdn dy ung lyc Id phucng phap hij'u hipu nang cao hipu qua ehing giu neo. Phii k i t hgp d u ung lyc hdi hda giua neo cdt th6p vd neo cdp d l ching giu d i t da xung quanh dudng Id dugc hipu qua nhit.
4. K i t lu$n
Cdng nghp ching giO su dgng neo cd't thep k i t hpp neo cdp trong cdc dudng Id md cho thiy hi|u qua rd r#t. Ld m$t logi hinh chong giQ- chu
d|ng, hudng cdng nghe chong giu nay phat trien dya tren hieu i>ng khai thdc t i i da kha ndng mang tai cua khii dd gia cudng. Ching giu kjp thci ngan can dugc hipn tugng sdm tdch Icp vd ed t h i tgo ra dugc d y ung lyc, ndng cao kha ndng chju tai cua dat da xung quanh. Dam bao duy tri dp I n dinh eua ducng Id, ndng cao chdt lugng ching giu.
Tren cc sd phan tich qua trinh biln dang dat da xung quanh ducng Id, nhdn t l anh hucng ehu y l u d i n biln dgng phd huy dudng Id ehing neo bao gom: Tinh chat cc hpc cua d i t dd, Cpng suit d i t dd xung quanh, tinh ding nhit lien khoi cua khii dd. tilt dipn ducng Id, v$t lipu vd k i t c l u ehing giO, anh hucng t u ban than Id ehg khai thdc vd Id chg Idn cgn. Trong d6, nhung thdng sd' cua hp ket cau neo cdt th^p k i t hgp neo cap Id rdt quan trpng, nhu lua chpn dp dan dai eua cap lam neo; dieu chinh l$eh thci gian thi edng neo cot thep vd neo cdp; dieu chinh dp len d y ung lye neo cot thep vd neo cap, de sao cho hp ket eau Idm vipc hi#u qua nha't, phd huy dugc t i t ca cdc Igi S\em eua hai logi neo. Ti> dd, gdp phin eho vipc (^nh hudng vd nghien cuu sdu de toi uu hda cde thdng s l thilt k l vd thi cdng dao ching, lya chpn hinh thuc vd vd cde tham so ching giu thich hgp, nhdm ndng cao dp on ^inh eua dudng Id, dam bao an todn va hipu qua kinh t l ky thudt./.
rdi li^u tham khio:
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[2] Trinh Dang Hung, Chen Chang Hua, Song Jia Lin, (2012), Active support works in under- ground mining construction execution and trends of its application, Proceedings of the 4th Interna- tional symposium on mine safety. China Liaoning Technical University.
[3] Zhaoqing Biao, Houchao Jiong.Manian Jie, (2015), Phuang phap tinh toan vi nguyen iy bo trq chong giCr neo va neo cip. Tgp chi Oai hpc Cdng nghp moTrung Quoc.
[4] Wangfei Hu, (2001), Nghien ciru phuang phip xic dinh cic tham so thiit ke va ca ly chong giu neo di/ ung iuc trong cong trinh ngam.
Dpi hpc Cdng ngh$ Tdy An, Thilm Tay, Tdy An.
KHCNM SO 10/2015* CNKT HAM L 6
