Nghiên cứu đề xuất thiết bị công nghệ thi công neo bê tông cốt thép nhằm phát triển áp dụng chống lò bằng vì neo

Thong tin khoa hoc cong nghe m o ^ NGHIEN CCJa t)E XOfiT THIET Bj CONG NGHE THI CONG NEO BE TONG COT THEP NHAM PHAT TRIEN AP DUNG CHONG LO BANG vi NEO Up to now, anchor bolts used together with shotcrete has TS PHAM MINH e i / C been the lightweight supporting structure applied to the underground constructions However, this type of the Vl$n khoa hpc Cdng nghi Md- Vinacomin Bien t$p: TS Tnrtmg Duv Dif supporting form has been so far not widely used in the supporting works in mines in Quang Ninh coal basin One of the main reasons is the limitation in their execution process The paper refers to the techndogy and equipment with using the reinforced concrete anchor bolts for increasing their application in supporting works in mines Cong nghg thi cdng lap dat neo va nhCrng vin d l cdn gidi quylt Tgi cdc md him Id vCing Quang Ninh, tu tn^dc din da dp dgng ching giu eac dudng Id ddo dd vd than bang mOt s i logi vi neo, nhu neo nem che, neo bd tdng c i t thep (BTCT), neo Ing hd vd g i n day Id neo chat deo cit thdp (CDCT), d6, dd san xuit dugc chat ddo thay t h i nh$p khiu Sllrarrf^TfTTfrnTfTTTfiTTTrr? * Neo n§m che (hinh 1): la logi neo dan gian v l elu tgo Phin cuoi thep neo dugc xe m6t ranh c6 ehilu ddi tir 20-30em De neo mang tai, chi cin ddng mgt chiee nem vdo phan ranh culi neo Cd t h i su dgng biJa hoac khoan ndn d l ddng neo Khod neo nem che mac du elu tgo vd che tgo khdng phuc tap nhung d l khod neo Idm vigc I n djnh can sy phu hgp ve dp bin cua logi da vd dp Idn lyc tdc dpng De dam bao yeu ciu tren Id tuang doi khd khan, vi the, chP den neo ndm che it dugc dp dung ' Neo CO hQC (hinh 2): nguyen tac Idm viee cua khod neo eung tuang ty neo nem che, dp bin cua dd qua eao hay qud thip deu khdng Hinh Neo dng hd thuan tien, khod neo khdng md hoac khdng thinh Id khoan Doi vo'i neo dng phdng, d l lim bam dinh tit * Weo ong ho (hinh 3) vd neo ong phong: Id viec, t^r\ bom dung dich de l i m phdng dng neo * Neo BTCT va neo CDCT (hinh 4): l i lo?i loai neo Idm viec theo nguyen ly ma sdt tren todn neo sy dyng chit b i m dinh l i vu'a bd tdng hoie bO neo vdi thdnh lo neo Khi dung mdy khoan ep Ing hd vdo Id neo, chat deo Vol neo BTCT, d l neo lidn kit vng suit ngang cua khdi dd nguyen cung nhu coi su l i p day be tdng dam bao dp chat Idm cho neo du kha nang mang tai (1): PHayl = P ji.d.z Trong dd C - Lyc bdm dinh giO-a eit neo vdi be tdng; neo trdn tran - 20mm thi C - IS - 30kG/cm2 vdi mdc bd tdng 150 -250kG/em2 Khi neo Id thdp gdn trdn thi C - 25 50kG/em2; OH - Lfng suit phap tuyen luc day hdng, c6 the Idy bang OH = A.y.H: A H$ s i day hdng 0,2 - 0,3 (Dp tdn cua ung suit khong nhOng chi phg thudc vao tinh chat dd (A) ma cdn phg thupe vdo dp eung eua c i t lieu be tong cung nhu phuong phdp dat cdt neo); fl - He s i ma sat giO-a thep vdi be tdng (fi = Hinh Sa dd moi quan h$ gli/a tai trgng neo BTCT 0,4 - 0,5); vdi chiiu dii do^n neo nam be tdng: T - Luc bdm dinh neo vdi be tdng, du^ng dOi - biiu thi c6t th6p bi chiy kG/cm2 Thanh neo ip 16-18mm, phin X/C Khi su dung neo hdng dd khdng chong 1:0; 1:4:1: 3: 1:1 va 1:2 gii> CO f< 3: neo) vdi dudng kinh khac nhau, chi can dat din P f (5) X/C, vdo dudng kinh neo nhung chilu ddi kfida khdng qud 30cm Khi cot thep ndm Trong do: sdu han, vigc tang tai chi Idm cho cot neo [i] - Dp ben eat cho phep cua be tdng hoac bj chay va dut dut Ngodi viee xdc dinh chilu dai khod neo bang dd khdng bang tai hdng khoi da; hai gid tri dp ben cat ddu nhd; thyc nghigm, cae tac gia [1], [2], [3] cdn su dung f2 - He so ma sat giu'a be tdng vdi be tdng phyang phap giai tieh de tinh toan chieu dai hoge da vdi dd; khoa neo Khi biet tai trpng neo P (tinh vdi h$ s6 dy tri> 4J - He s i tfnh tdi su tham gia cua dign tich an toan k) Chilu dai khoa neo b neo BTCT anh hudng cua dp ben cat, lay bang 0,2 - 0,3 TTKHCNM SO 6/2015* CNKT HAM L Thdng tin khoa hoc cong nghe mo Theo hudng dan tinh todn thilt k l vd su dgng neo BTCT, CDCT [4], sau khoan Id neo, v§ sinh lo neo, ein ehuan bj vgt ligu bdm dinh d l dua vdo lo neo Vdi neo BTCT la vigc bam vua be tdng vdo Id khoan neo VO'a be tdng Id hin (6) -a >P hgp xi mang, cdt, chit phg gia, chit dpn, nudc, sau djnh lugng dugc dua vdo thung trpn, may se trpn d i u cdc phin cot ligu Thilt Suy (7) bj ngp vu'a vdo l5 neo Id binh hinh trg (hinh 7) co kha nang chju dugc dp suit ndn 2-3 atm, Trong do: mpt d i u cd nap de ngp hdn hgp be tdng tiKt'\ Op - Dp bin keo tinh todn cua thep CT3 Idy dau cdn Igi n l i vdi dng d i n bd tdng De bom bd bdng 2100 kG/cm2 tdng vdo Id neo, su dgng nen dp suit 2-3atm Nhu vgy, chilu ddi khod neo lien quan din tai Khi nen xuyen qua Idp be tdng vd thii ngoai trpng, vd ehilu dai khda neo bdm dinh nam kdm theo hon hgp vdo lo neo mpt gidi hgn nhit dinh Trong tinh todn thiet k l Trong xdy dyng cdc cdng trinh nglm giao ching giO dudng Id bang neo BTCT hay CDCT bang nguyen ly treo, d i m hay khod thi khod neo thdng, thuy dien, thuy Igi , vi$c ngp vua be tdng vdo l5 neo dugc ca gidi hod vd ty dgng hoa ludn giu' vai trd quan trpng hg thong vi neo - khii dd Nlu chieu dai phan khod neo thi cao De ngp vCra be tong vdo IB neo sdu 5-7m cdng khdng du, dp ben ciia vgt Ii0u khod neo ngudi ta khdng su dung binh ngp nhu hinh ma khdng dgt, dd khd ndng chju tai eua neo su dgng thilt bj t l hgp khoan, nap vua Sau khoan xong mdi lo neo, may khoan neo (boltec) khdng dam bao su dgng bom be tdng dp suit eao de phgt vOa bd tdng vdo Id neo Sau ngp vua vao lo neo, bp phgn ein mdy se dua cit neo vdo 16 De giu* cho neo khdng bi tupt ngodi, tay ngp ty dpng be cong neo, sau dd dung nut gd hoge vai ehgn vu'a chay ngodi cho tinh todn vd ching be tong giing dung gieng khdng cd vanh chong trugt Dudng kinh neo dugc tinh theo (6): Hinh Kit ciu neo BTCT l5 neo a-|»uf 4llJi!t> voj IT Hinh Binh nap vOa be tdng vio l6 neo i r K I I C N M S O 6/2015'CNKT n x M L O Hudng cam cua neo dudng 16 dupc bo tri theo hinh re quaL Cdc neo vudng gdc vdi mgt Ip vd nghidng vdo phia tim 16 Neo noc Id neo chju tdc dpng cua ty trpng khoi dd va ludn eo xu hudng rai vdo tdm trai dit Ngp vu'a be tdng vdo Id neo bang binh bam ndn Id mpt cdng vi0c phtpc tgp, khd khang (flnh chit lugng vua cung nhu muc dp lip diy va kha nang chen ehgt D i u tien, de ddng nen xuyen qua cac Id rdng vu-a vdi dan, dp suit nen binh bi ddng kin ndn tang len nhanh Khi ddng nen thing dugc sue can eua *ua be tdng, dy tru the nang Idn nen vO'a be tong se phun mgnh Neu thao tac khdng dung qui trinh hoge d l vdi phun khong dung hudng, vua be tdng b i n vdo thiet bj thi cong vd ngudi guong se gdy nguy hiem Bgm phgt thdi diem d i u cd toe d | Idn se gay bgt niy mgnh Vi>a bam Id dung djch khdng dge, d l tgt tgi cdc Id doc ddng Ddy Id nguyen nhan Thong tin khoa hoc cong nghe md Idm cho khod neo khdng dugc l i p day vd chen chdt, Idm giam tai trpng neo Qua trinh kiem tra tai trpng bang keo rut nhd neo khdng phan dnh thyc t l tai trpng neo Dii la nap vua be tdng bang binh bom (hinh 7) hay su dgng bam tia cua mdy khoan ngp neo Boltec thi v i n de thudng xay Id ddy Id khoan rlt khd bao dam su lip day VO'a be tdng chi dugc giu' lai dua neo vao va dung nOt d l ching vu'a rai Theo nguyen |i? lam viec, neu chieu ddi khod neo vung da ddn hoi khdng dam bao Itt < Ineoc^ttvit, kha nang mang tai cua neo se bj giam Nhu vdy, doi vdi mdi logi neo, loai chit bam dinh, thilt bj vd cong nghg thi cdng cho thiy cdn cd nhung v i n de can nghien ci>u, hodn thign d l ddp ung yeu elu nang eao san lugng vd gia thdnh phu hgp, dd Id: Ve v$t liiu: - Neo BTCT la logi neo vdi nhieu uu ^em ve kha nang chju luc, ve cung d p vat lieu, v l gid thdnh Nhung cdng nghd ngp vO'a khdng phuc tgp Kha nang l i p diy khdng chde chan, dan den su khdng dam bao dong deu v l tai trpng eua tdt ca cdc neo - Neo CDCT thi vdi chat deo, dieu kign bao quan, thdi gian tuu kho vd ddc biet gid thdnh la van de chua that h i p dan vdi ngudi su dgng Ve thiet bj thi cong: - Neo BTCT khong ddi hdi thiet bj thi edng chuyen dung khoan lo neo, khdng han ehe toe dp chong giu Id, nhung thilt bj nap be tdng ddi hdi muc d0 an todn cao; khd quan Iy toe dp phgt vua vd su l i p day, d i xay nhu'ng bat trac - Neo CDCT ddi hoi thiet bi, phg kien chuyen dung, dong bp, dung chung loai (may khoan neo, mdyxietneo, buldng neo ).Ddihdikythudtva trinh dp thi cdng Dae bigt, thdi gian luu kho ngan, dieu kign bao quan chat che, can thilt bi bao dn d nhigt dp thip, it thay doi Gan day, thay vi su dgng thdi chat deo, hay si> dung binh ngp vu-a be tdng nhdm thudn tign thi edng vd gid thdnh, mpt sd nai tren t h i gidi vd nudc da hodn thien cdng tdc ching giu neo BTCT theo hudng: 1) Su dgng cdc thdi xi mdng khd; 2) Su dung thiet bj dun vij-a ngp vdo lo neo 1) SO' dung cac thdi xi mang kho Cdc hang Minova, Sika vd cdc nhd san xudt vat lieu be tdng tai Trung Qulc che tgo cae thoi xi mang khd ddng gdi ed chieu ddi tu 250 350mm, cd mdng ching tham, dugc bao ve bing bao polyethylen Khi thi cdng, lay thdi san phim ddng gdi khdi bao polyethylen va ngam vao nudc, d l cho nudc cd t h i tham du vdo san pham qua mdng, tao nen vu'a gdc xi mang thixotropie, khdng co ngdt Chit ho trg vua bao dam su co gian c6 the kiem scat dugc d l on djnh vO'a vd kiem sodt sy hut nudc d l cung d p ty Ig N/X toi uu, dgt cudng dp cao sdm Tinh lien kit tong the cua vu'a cho phep su dung san pham dieu kign udt, thgm chi ca tnfdng hgp nudc ehdy tu Id khoan gidi han cho phep khdng lam trdi vO'a Dac diem cOa cac thdi xi mang khd nhu sau: • Khdng dpc to, khong eo elorua; • Khdng d n phdn loai d n van chuyen;• Cd the su dgng ngay; • Khd nhanh vd rlt cung; • Dp bin culi cung cao; • C6 the dung nhu Idp vu'a bu co ngdt; • Khdng d n may bam hoac mdy trdn; • Quy trinh lap dat nhanh vd dan gian; • Thdi gian bat dau ninh kit 12 phut, thdi gian kit thuc ninh kit 60 phut, d nhigt dp 21*'C Khi nhigt cao thi thdi gian tren ngan lai Thi cong Id khoan neo, Id khoan phai khoan d i n chieu sdu qui dinh bang mdy khoan xoay dap hoac dap xoay vd phai kilm tra de bao dam sgch vd khdng bj vudng ket dd Cdc thdi xi mang ddng gdi phai l i y khdi bao lolyethylen vd ngdm vdo nude it nhat Id phut vd thay edn c6 bpt thoat tu thdi xi mang thi phai ngdm den 03 phut Khi quy djnh ve lam udt thdi xi mang hodn tat, lay thdi xi mang ra, cho vdo Id khoan Thoi xi mang phai cho vdo tan ddy Id khoan bang mpt nhoi hoac vgt lieu de nhoi, diy thdi xi mang vao day 16 khoan neo Tat ea cdc thoi xi mdng djnh muc cho mpt 16 phai dugc dua vdo Id nhanh ehdng vd cung mpt thdi gian Thanh neo dugc day vdo Id d l pha vd bpc Cd the dung mdy khoan de ddy neo, vua d i y vua xoay vdi t i c dp ti> 150 4000v6ng /phut 6k dua thah neo vao day Id neo 2) Thay the binh bom be tong bang thiet bj TTKHCNM S6 6/2015* CNKT HAM LO Thdng tin khoa hoc cong nghe m o nap dun be tong Sir dgng nang lugng nen de phun be tdng, khd khan eua vigc 1dm chu dugc qua trinh bam phgt nen chit lugng vd dp lap day, kha ndng chen ehgt khd bao dam Nap be tdng bang phun nen, su dgng ddng d l day vua khoi binh phun nen ddng phun bj tae dong eua kich thudc hat, trpng lugng ban than hgt, mue dp bam dinh giu'a cdc hat nen hon hgp be tong bay vdo 16 bj phdn tan, phan Idp Tgi phin khod neo - phin sat day Id neo be tdng ehu y l u la cat, bpt dd mjn vd mot lugng xi mang xi mang nhd [5] C i t ligu thd, bd khung chju luc cua be tdng ndm d phan giu'a hoac dudi neo, do dg t>en cua be tdng phan khod neo khdng cao so vdi phan thdn va dudi neo Mat khde, be tdng khdng lip diy day Id nen chilu ddi khoan bj gidm v.v dan den sy dam bao dac tinh ky thuat cua khod neo khdng ehac chdn Hinh Ddng vQ^ bi tdng khdi miy dun ddi khod neo dugc l i p ehgt kin bang vOa be tdng nen chilu ddi vd dp b i n be tdng ludn ehac chan Vdi mdy ngp dun be tdng, nen chieu ddi tinh toan khod neo cd t h i loai bd he s i du' tri> 1,3-1,4, tilt kigm dugc chieu ddi du phdng Id neo cung nhu chieu dai neo dy tru sai so thi cdng Thilt bj dun gon nhg, an todn eho ngudi dilu khiln Higu qua kinh t l thilt bj mang lai Idn, dd la vigc rut ngan chieu ddi Id, chilu dai neo , cdi thign dang ke ve moi trudng, an todn thi cdng, khdng ddi hdi nguyen eong ngng nhpe nhu ngp vija bang nen vv Tdm lai: De cai thign dilu ki0n lao dpng, an toan, giam thilu tdc dpng khdng t i t d i n mdi trudng, tilt kiem chi phi vd giam gid thdnh ching Id bang vi neo BTCT, vat ligu - xi mang thdi khd va thiet bj nap vua be tdng dugc nghien cuu gidi thieu la nhu'ng vdt lieu thiet bj da va dang dugc su dung nhieu xdy dyng cdng trinh ngam va md May dun vu'a be tdng hoat dpng theo kilu tmc Vdi vdt lieu vd thilt bj thi edng tren se gdp phan xodn nen khdng sinh bui, an toan qud trinh de phdt trien neo BTCT ngdy mgt rpng rdi hon ngp vi>a Vu-a dugc day trdn ddy 16 neo Chilu ngdnh Than./ D l thay the ddng chay phdn tang cua hdn hgp be tdng thdnh ddng chay roi, nhilu hdng c h i tgo mdy thi cdng da san xuat cae thiet bj nap be tdng theo dgng dun Nguyen ly Idm vigc cua may nap vua be tdng tuang ty cdc thiet bj "xay, nghien thit" su dung d l xay hay bam thit Hdn hgp bd tdng tuai duge nap vdo binh hinh trg, dd cd dgt mpt trg xoan cycloit Khi taic xoay hon hgp be tdng tuoi theo cdc ranh xodn d l dun ngodi Toe dp xoay cua tmc quyet djnh din chieu cao nap vd vigc dun h i t s i lugng be tdng tuai mdy dun Thiet bj dun be tong gidi thigu tren hinh Tdf lieu tham khao I.Kazimierz Podgorski, Wladyslavi/ Podgorski, 1969 Obudowa Kotwiov\/a \A^robisk Gomiczych., V^davmictvx) "Slask" B M PoauHCKuu HpoeKmupoeaHue upaoiem )Kene3o6errK}HH0u Kpeno 1971 MocKsa Hesopa S H CeMeecKuu tUmaHaoeaa Kpen M MeTannypmsflarr Huung dan si> dung neo BTCT ket hop be tong phun kho - TKV; HiKmg din s u dung neo CDCr-TKV Sika Rokkon C-VN; Meyco Masterbond Hinh l\AAy dun vCra tii tdng vio l5 neo Gidi thigu san phim TTKHCNM S6 6/2015* CNKT HAM L ... tinh todn thilt k l vd su dgng neo BTCT, CDCT [4], sau khoan Id neo, v§ sinh lo neo, ein ehuan bj vgt ligu bdm dinh d l dua vdo lo neo Vdi neo BTCT la vigc bam vua be tdng vdo Id khoan neo VO''a... ddi khod neo vung da ddn hoi khdng dam bao Itt < Ineoc^ttvit, kha nang mang tai cua neo se bj giam Nhu vdy, doi vdi mdi logi neo, loai chit bam dinh, thilt bj vd cong nghg thi cdng cho thiy cdn... cdc neo - Neo CDCT thi vdi chat deo, dieu kign bao quan, thdi gian tuu kho vd ddc biet gid thdnh la van de chua that h i p dan vdi ngudi su dgng Ve thiet bj thi cong: - Neo BTCT khong ddi hdi thiet