Ngoai viec khoan cae Id khoan tham dd ti mi, viee do dac dja chan, dja vat ly, quan trie thi ehung ta edn can phai cd dau dc am hieu ve diiu kien dja chat de phan doan them nhung tin[r]
(1)Hdi NGHI KHOA HOC KY THUAT MO TOAN QUOC LAN THIJf XX CNM
NANG CAO HIEU QUA THI CONG CONG TRINH NGAM KHI SU' DUNG MAY KHOAN HAM
ThS TRAN TUAN MINH - TrUdng Dai hgc Mo-Dja chat KS N G U Y I N VIET DjNH - Vien Khoa hgc Cong nghe Mo-TKV
k k ien sy phat trien cDa khoa hpc ky
rl thuat va viec ap dung eac tyu khoa • i hpc ky thuat vao san xua't, eae may mdc hien dai cang dupe ap dung rpng rai vao tiiyc t i san xuat de nang eao hieu qua lao dpng Trong cac loai may hien dai tren cd may klioan him TBM (Tunnel Boring Machine) May khoan ham TBM vdi eae chac nang khoan him, thi cdng him toan tiet dien ed tfnh cd gidi hoa eao, td'c dp thi cdng nhanh da dupe ap dung va da thu dugc kit qua cao b tren the gidi va k i t qua nhat djnh b Viet Nam (H.1)
Tuy nhien, hieu qua thi cdng cdng trinh ngam bang eae may khoan ham TBM phu thudc vao mpt to hpp eCia ra't nhieu yeu td khac ty qua trinh tham dd, lya chpn phUdng an TBM den viee thi cdng khai dao, ehd'ng giu, v.v cung nhu hoan thien cac hang muc cCia cdng trinh Bai bao phan tfch mpt sd van d i lien quan den hieu qua thi cdng cdng trinh ngam bang may dao him TBM va dUa mpt sd bien phap khac phue
2 Cac ye'u to anh hudng tdi hieu qua thi cong ham bing may khoan ham TBM
2.1 Anh hudng eua cae yeu to khach quan dja chat de'n thi cong him bang may khoan him
• Su thay doi dieu kien dia chat khu vuc thi
cdng dudng him
Sy thay doi dja chat thudng xuyen gay anh hudng Idn din hieu qua may khoan ham May khoan ham thudng dugc ap dung cho nhung khu vyc dja chat ft ed tfnh biin ddng thay dd'i lien tue tren ehu tuye'n cCia cdng trinh, diiu kien dja chat thay ddi thi anh hudng den viec sCf dung cae loai rang cat khac nhau, dieu kien thi cdng cho tang loai TBM la khdng hieu qua Viec tham dd dja chat khdng dung cd the dan tdi viee dyng may TBM hoac viee lam sap gUdng him cung nha khd'i da't da xung quanh cdng trinh ngam
• Yetv td nudc ngim
Sy thay doi myc nudc ngam cung nhu ap lye cCia nadc ngam tac dung den guong dao cung gky
anh hudng den hieu qua thi edng cdng trinh nglm bang may khoan ham Cu the ap lye ehd'ng giu guong khdng dCi de chdng lai ap lyc nude d xung quanh lam eho nude bun da't cd the tran ngap vao dudng ham, ye'u td nude ngam ed tfnh an mdn eung lam mdn rang cat, d i u c l t eung nhu thiit bj cCia may khoan ham
H.1 May khoan him TBM tai cCta ham Dublin -Dublin, Ireland 2002 (a) va may khien dao (S-M)
dimg cho da't yeu (b) [2]
• Ye'u to da't da bj nen ep manh su thay doi
Ung sua't da
Qua trinh khai dao dudng ham se giai phdng yng suat bj nen ep da't da sinh mpt sd hien
(2)HOI NGH! KHOA HOC KY THUAT MO TOAN QUOC LAN THUf XX
tupng nha trdc vd, pha vd qua cd, cung nhu sap dd' dat da vao cdng trinh ngam va budc phai dyng viee thi edng dudng ham lai de ehd'ng giu dadng him
2.2 Anh hudng cua cae yeu td chu quan cong nghe den hieu qua thi cong him bang may khoan him TBM
• Yeu to true tiep vi may khoan him: Td'c dp
thi cdng dadng ham phu thudc vao loai may khoan ham TBM va eae trang thiet bj phu trp di kem, cung nha kha nang cung Cfng thiet bj phu tung thay the hong hdc cua dPn vj thi cdng Khi cd sy thay doi dat da thi cung din den mac dp hao mdn rang eat khac nhau, viee thay ddi rang cat tren dau cat cung lam cham tiin dp dao him bang may TBM Thdng thudng eac da ed dp cCfng Idn, tfnh chju mai mdn cao thi chi phf rang clt eho dao ham se Idn hdn trdng dat da mem yeu va thdi gian thay rang eat qua trinh khai dao eung phai tang len, dd ma td'c dp dao him se bj cham lai
Ngoai dd'i vdi may qua trinh hoat ddng edn cd the bj hdng cac bd phan ban than may nhu: Bp phan dau dao, bp phan nang dd kit cau chdng, bp phan eung cap khf nen, bd phan xCf ly bui, se din d i n budc phai thay the hoac sCfa chaa ehung bang cac thiet bj dy phdng Nhu vay thdi gian lam viee cd fch cCia may cung bj giam di va td'c dp thi cdng dudng ham bj cham lai
• Yeu td lam giam tdc thi cdng him kich
day TBM ty len ket cau lam hdng ket cau phai thay the ket cau chdng
Khi khai dao va di chuyen TBM cd the eae kfeh thu^ lyc se ti len phan kit eau da ehd'ng giy d phfa sau hdac viee ty len da't da de tao lye day kich dau day tham nhap vao da't da hoac de di chuyen TBM cd the gay hien tupng pha huy kit elu ehd'ng giu hoac lam hu hai fie thdng ludi thep, be tdng phun (niu ed) hoac khdi da xung quanh dudng him bude phai xCf ly va nd eOng la nguyen nhan lam giam hieu qua hoat dpng eCia may TBM
•> Yeu t6 thi cdng dudng him bang TBM gay
lun be mat dat lam giam hieu qua thi cdng dudng him bang may TBM
Odi vdi nhyng dudng h i m nam gin mat dat thi viee thi cdng eac dudng ham bang TBM thudng gay eae bien dang lun b i mat lam anh hudng d i n cae cdng trinh tren mat Nhieu trudng hpp viec khai dao dudng ham cdn lam hu hong d i n eae edng trinh tren b i mat, dd bude phai dang viec khai dao dudng ham lai de khac phuc eac sy ed sau mdi tiep tue dao dudng h i m
Nhu vay viec khic phue sy ed se lam giam tiin dp thi edng eung nhu tang thdi gian may chit
(khdng hoat ddng) cCia may lam giam hieu qua thi edng him
• Yeu to bui, cap nudc, chieu sang bi hu hdng hoac kem chat lupng cung lam giam hieu qua tdc dp thi cdng him bang cae may TBM
•:• Ye'u td van hanh, tay nghe cCia ddi thg thi
cdng, phan doan du doan cua chuyen gia khdng
hpp ly cung lam giam hieu qua thi edng edng trinh ngam bang may khoan ham TBM Khi thi cdng lap dyng ke't eau chdng, kit elu chdng tham ed the ed mdt sd tinh hudng gay nguy hiem dd'i vdi edng nhan, anh hudng xau d i n toe dp dao ham bang may TBM
3 Giai phap khac phuc
Nhuda phan tfch b tren, hieu qua hoat ddng cCia viee thi cdng bang may khoan ham phu thude vao td'ng the cCia rat nhieu yeu to khae Cho nen, giai phap khae phue khdng nen phan biet nang nhe
b ta't ea eae khau nao cd anh hudng din tdc dp dao
h i m Cac bien phap ed the ke den la:
••• Thur nhat: trude quyit djnh lya chpn loai may khoan h i m nao thi ehung ta can phai cd danh gia, quan trie, dieu tra khu vyc dja chat xay dyng dudng ham mpt each hit syc ti mi, vi viec dau ta may khoan h i m can sd lupng vd'n ra't Idn Ngoai viec khoan cae Id khoan tham dd ti mi, viee dac dja chan, dja vat ly, quan trie thi ehung ta edn can phai cd dau dc am hieu ve diiu kien dja chat de phan doan them nhung tinh hudng cd the xay de dua bien phap lya chpn may eung nhu viee dy tfnh eae y i u td ty dja chat anh hudng d i n qua trinh khai dao dudng ham
• Thur hai: Vdi nhyng khu vyc ed nude ngam ehay vao cd the xCf ly bang each sau: bdm chat dinh kit vapt trade gadng ham de tao sy d'n djnh, ngan chan nadc ehay vao trade thi edng Vdi viee lam nay, cac thiit bj khoan Id khoan va bdm ehlt dfnh k i t phai dapc lap dat treng may dao va viee khoan bdm ep xung quanh dudng ham cd the dai den 25m de xi mang hea Hdac phfa trade gUdng h i m dat da yeu ed the phai khoan tao d vdm, cape gUdng trade khai dac
•:• Xu" ly nudc da chay vao dudng ham bang each tang edng sua't cua may bdm nude Cd t h i dung bien phap myc nudc nglm, bdm ep chat each nadc, ddng bang nhan tao,
•:• Thur 3: Xu ly su co ve rang c a t Khi rang elt bj hdng, hao mdn se lam giam kha nang elt da cCia dau cat Niu rang eat kem thi s§ thudng xuyen phai thay ddi lam giam thdi gian hyu fch eCia may khoan ham, dd cung lam giam td'c dp dao him bang may Cach khae phue td't nha't la tang cudng chat lupng rang cat, lya chpn cac d i u rang c l t dupc c h i
(3)HOI NGHI KHOA HOC KY THUAT MO T O A N QUOC LAN THIJf XX CNM
tao ty cac hpp kim cd kha nang cat Idn va tfnh^ bj mai mdn tha'p se tang tud'i thp cCia rang eat, giam thdi gian chit may va tang hieu qua thi cdng h i m Trong trudng hpp thudng xuyen gap van d i da qua cyng thi cd the de'n nhung ndi nghien cyu chuyen sau ve dat da de cd the cd dapc nhung ehi dan eu the each eai tiin cac k i t qua cat cho nhung cdng ty cung cap rang c l t eho may khoan him Cd the sCf dung cac rang cat ed chya vonfram-eaebua, de tang cudng kha nang eat da eho may Tuy nhien, viec sCf dung rang cat vonfram-eaebua thi thudng keo theo la gia mua rang cat eao nen thye t i thi ngudi ta cd the dung ke't hpp ca rang eat vonfram va rang elt thudng
•:• Thiir4: Xur ly sirco ve bui, ro dien va chay no Ban than may TBM va eae thiet bj phu trp eung nhu toan bp cac thiet bj ed lien quan den may TBM phai dupe each dien de ngan ngya hien tupng ehay nd tia iCfa hoac bj nung ndng qua nhiet dp cho phep
Can phai lap dat eae dung cu phat hien sy rd ri cCia khi, tinh toan thdng gid va cd chu y den lupng va bui cd the sinh ra, dao ham da eang, bui thudng xuyen xuat hien Nd khdng ehay nhung rat nguy hiem ddi vdi sac khoe neu hit thd phai bui thdi gian dai Do dd, cdng tae thdng gid can phai dam bao dem gid sach vao de hoa loang khf ddc va bui xud'ng dudi nong dp cho phep va dua ddc khoi khu vyc lam viee
• Thur 5: x u ly sir co' cac khau dao ham Dao ham bang may cd rat nhieu cac khau edng tae khae ty c l t da, xCf ly gadng, ehd'ng tam, ching ed djnh, van chuyen ke't ca'u chdng, dat da Do dd, eae khau can phai nhjp nhang va lam viec an toan, hieu qua Neu mpt khau nao dd gap sy cd thi hien nhien nd ed anh hudng den cae khau khae va hieu qua lam viec cua may dao him cung giam theo
4 Ket luan
Qua mpt sd diem phan tfch b tren ed the nhan tha'y rang viee thi edng xay dyng cac dudng him du bang phUdng phap truyin thdng thdng thudng hay thi cdng bang may cd gidi thi hieu qua eua chung phu thupc vao ra't nhieu cae yeu td khae Mdi yiu td diu cd nhung anh hudng nhat djnh den hieu qua cung nhu chat lupng cdng trinh nglm Viee phan tieh, dy doan eac y i u td nguy hai lam giam hieu qua hoat dpng dao ham eCia may khoan him TBM cd y nghTa rat quan trpng de dem lai hieu qua cao thi cdng bang may Trong tUdng lai thi eae may khcan ham se cang dupe sy dung rpng rai thi cdng xay dyng Do dd, ma ehung ta can phai xem xet, dy doan ta't ea cae tinh hudng cd the gay nguy hiem, bat Ipi qua trinh thi edng
bang may dUa dapc eae bien phap khae phuc can thiet de nang eao hieu qua lam viee bang may khoan ham.d
TAI LIEU THAM KHAO
1 Safe working in tunnelling Prepared by the ITA working group " Heath and safety" and financed by TBG and ITA
2 G Sauer, Ph.D, P E., Walter A Mergelsberg, Dr.G SauerCorp., Herndon, VA USA; Salzburg, Austria; London, UK - Tunneling and beyond 22/10/2004
3 Giovanni Baria, Department of Structural and Geoteehnieal Engineering, politeenieo di Torino, Tunnelling under squeezing rock conditions
4 Erie Leea\ Yann Leblais^ va Kari Kuhnhenn^ Underground works in soils and soft rock tunneling Erie Lesea, SCETAUROUTE/DTTS, Groupe EGIS, Les Pleiades n° 35, Park Nord Annecy, 74373 Pring Cedex, France
6 Yann Leblais, EEG SIMECSOL, Consluting Engineers, 18 me Trdyn, 92316 Sevres Cedex, France
7 Kari Kuhnhenn, BUNG GmbH, Englerstra8e4, Postfach 101420, 69004 Heidelberg, Germany
Ngudi bien tap: Ninh Quang Thanh
SUMMARY
P paper introduces reasons, effects and „|; overcoming methods to increase executing efficiency of underground constructions using road headers, the machines that should be widely used in the field of the tunnel excavation nowadays
LiiLHtir-tqj.-1 Tin tudng qua la dadng d i n den nhu'ng dau kho' Tuc ngCr Italia
2 Luong thien la gia trj hang dau di trade mpi gia trj chan chinh va ca gia trj tham mT
F Voltaire
3 Nhu'ng ta Idn thadng di ty trai tim I6n, nhung an tinh nang thadng de'n ty le phai Cach ngon
4 Khi tranh cai vdi mpt ngadi, can cham
lo de sau cupc tranh cai ta c6 mpt ngadi ,ban Diodore
VTH suxi tam