Thong tin khoa hoc cong nghe mo MOT SO VAN OE TON TAI TRONG THONG GIO CUC BO KHI THI CONG CAC DUfOfl̂ G HAM, DlfCfNG LO VA BIEN P H A P KHAC PHUC S'''' firrrf^sr • ihibtibn works is one ofthe important p[.]
Thong tin khoa hoc cong nghe m o MOT SO VAN OE TON TAI TRONG THONG GIO CUC BO KHI THI CONG CAC DUfOfl^G HAM, DlfCfNG LO VA BIEN P H A P KHAC PHUC S'-firrrf^sr • ihibtibn works is one ofthe important problems in the excavation and construction of the tunnels However, the designation and installation of the ventilation system has many limitations This paper refers to some existing problems of local ventilation during executing tunnels and overcominq solutions '-Ji KS PHAM NGOC HUY Cong ty Co phan Tuvan va Xay lap Ha Ngi KS DAO VIET DOAN Trudng Dai hgc Mo- Dja chai -/, Oat van de Thdng gid thi cdng cac dudng Id la mdt nhung van de quan trgng cac md ham Id cung nhu viec xay dyng cac dudng ham va he thd'ng ngam Muc dfch eCia viee thdng gid la eung cap lUdng khdng khf sach dam bao cho ngudi cdng nhan lao ddng dudi ngam va Iam Ioang c^c khf cd kha nang gay nd, lam mat khdng khf md va mdt sd muc dich khac Hien nay, de thdng gid thi cdng cac dudng Id ngudi ta thudng sCf dung phUdng phap thdng gid cue bd, va thydng SLf dung mdt ba sg thdng gid la: sg thdng gid day, sg dd thdng gid hut va so 66 thdng gid hdn hgp Trong ba sg dd thdng gid thi phygng phap thdng gid day la phUdng phap dUde sCf dung nhieu nha't vi nd ed nhung Lfu diem la nhanh chdng lam Ioang ddc, va eung cap du lUdng sach cho cdng nhan lam viec Tuy nhien, phUdng phap thdng gid cue bd hien cdn cd rat nhieu van de han che can dygc giai quye't nhy chgn quat gid khdng dung, chgn dydng dng khdng phu hgp, rd ri gid d cac chd ndi, qua trinh van hanh quat va thiet bj, v.v Bai bao gidi thieu mdt sd van de tdn tai va bien phap khae phuc thdng gid cue bd thi cdng cac dudng ham Cac van de ton tai thong gid cue bo Hien thi cdng xay dyng cac dydng Id cae md ndi chung va xay dyng eac cdng trinh ngam ndi rieng thudng SLf dung sg dd thdng gid nhU hinh Cd rat nhieu cac van de cdn tdn tai va cd anh hudng tdi hieu qua cCia edng tac thdng gid cue bd qua trinh thi cdng xay dyng cac dudng Id, cd the ke de'n nhy la: quat va vi tri lap dat khdng phu hdp: Thdng thudng la quat cd cdng sua't nhd dan de'n kha nang khdng dam bao lull iLfdng gid dap Cfng yeu eau theo tinh toan Do dd, viec hoa Ioang bui, khf nd, khf ddc hai rat khd khan, dac biet la sau nd + Quat va dng gid khdng a) Sa thong gio day b) Sa thong gio hut + Tfnh toan luu lygng gid eho dudng ham thudng lya chgn phUdng phap tfnh toan khdng phu hdp vdi sd 66 thdng gid, cung nhy yeu cau thdng gid Hinh Cac sd dd thdng gi6 tich cue thi c6ng xay dung cac dudng 16 + Chon loai 1) quat gio; 2) ong gid; 3) cCra chan gio KHCNM SO 8/2010* CNKT HAM LO c) Sa thdng gio hdn hgp Thong tin khoa hoc cong nghe m o ddng bd (quat cdng sua't nhd dung dng gid Idn, quat cdng sua't Idn dung dng gid nhd) Ddi tren cung mdt tuye'n dng gid lai sCf dung nhieu loai dng gid cd dydng kfnh khae nhau, viec lam tdn hao gid va thay ddi td'e truyen gid lam giam hieu qua cCia cdng tac thdng gid + Chgn dudng dng gid va lap dat khdng phu hgp lam anh hydng de'n hieu qua cCia cdng tac thdng gid thi cdng dudng Id Trong qua trinh lap dat dng gid, mdt sd yeu td chua dam bao yeu cau ky thuat nhU: - Cac ehd ndi doan dng gid khdng dugc kbit din de'n tinh trang rd gid - Vat lieu de ndi cac doan dng khdng phu hgp, qua trinh thdng gid dan den hd md'i ndi - Ghep ndi cac doan dng gid khdng cung ehCing loai hoac kfch ed - Khoang each giCfa cac mdc treo dng gid khdng dung vdi thie't ke - Do vdng cCia dng gid cdn Idn hon quy djnh cho phep - Khi dao nhu'ng dudng ham cd dia chat khdng dn dinh he sd lem Idn thi cang va thing can thie't cCia dng gid chua dap Cfng yeu cau - Tai nhung vi tri chuyen hudng cua dydng Id thi gdc chuyen hudng cCia dng gid thudng khdng tron deu, sd lygng mdc tree dng ft hgn thie't ke - Mdt sd cdng trinh lap dat vi trf dng gid tren mat cat ngang Id khdng dung so vdi thie't ke Dydng dng gid cd the bj treo d hdng ham gan dydi nen dydng Id hoac treo lech len dinh Id + Luu lygng gid gydng Id khdng dap Cfng yeu cau, tieu chuan va theo quy pham + Ndng bui va khf khdng khf tliydng khdng dap Lfng tieu chuan cho phep + Cdng tac thdng gid sau mdi lan nd mln chie'm nhieu thdi gian eho mdi chu ky tie'n gifdng + Quan ly thdng gid - De lay gid mat cho ban than, cdng nhan thie'u y thCfe lao ddng tim each lam rach dng gid dgc dudng Id - Qua trinh van hanh may mdc, thie't bj xuc bdc, van chuyen da't da khdi gygng ham cdng nhan thieu quan sat de thie't bj va quet vao dudng dng gid din de'n rach, thung dng gid - Trong qua trinh van chuyen, mang vac vat lieu chd'ng giOf vao dudng Id cua cdng nhan nhu cac neo, vi chd'ng tam, cung la nguyen nhan gay rach dng gid - Mdt sd trudng hgp he thd'ng dng din khf, nude, dung dich dugc treo chung vdi mdc treo dng gid lam dng gid bi vdng hoac thung, rach gay tdn that va giam hieu qua thdng gid - Tai cac md'i ndi dng gid, sau qua trinh boat ddng ed the bj hd hoac rach ngudi lao ddng thie'u ty giac sCfa chu'a, hoac bao cao vdi quan ddc, KHCNM SO 8/2010* CNKT HAM L hoac trydng ca de khac phue, SLfa chu'a kip thdi - Viec van hanh quat gid mdt sd trudng hgp chUa dieu chinh kjp thdi nhy sau nd can luu lugng gid ldn de thdng gid nhanh - Ngoai cdng tac kiem tra, bdi dudng kie'n thCfe ve an toan lao ddng eung nhu y thCfe td chCfc k^ luat cho cdng nhan cCia mdt so dgn vj thi edng ham cdn ban che + Bd tri khoang each giua cac quat ndi tie'p khdng hgp ly' Cach khac phuc cac van de ton tai 3.1 Cong tac tinh toan De chgn dygc lull lugng gid can thiet cho cdng tac thdng gid thydng tfnh luu lugng gid theo cac yeu cau sau: + Theo sd ngudi lam viec ddng thdi Idn nhat gygng ham tfnh theo cdng thCfc: Qng = e.n.kn, m^/phuL (1) Trong dd: - Djnh mufc lugng gid sach cho mdt cdng nhan, m^/phut n - Sd lUdng cdng nhan lam viec ddng thdi Idn nha't tai gydng ham kn - He sddytry + Theo lygng thud'c nd ddng thdi tfnh theo cdng thCfc cua GS TS Voronhin: Trong dd: t - Thdi gian thdng gid tich cyc cho gygng ham Thong tin khoa hoc cong nghe m o A - Lygng thud'c nd ddng thdi Idn nha't S - Dien tfch tiet dien Id L- Chieu dai dydng Id dugc thdng gid + Luu lugng gid theo tdc nhd nha't tfnh theo cdng thCfc: Q,a = eO.Vcp.S, m3/phCit (3) Trong dd: S: Tie't dien dUdng ham can thdng gid Vcp: Van tdc gid nhd nha't eho phep (trong quy pham quy dinh van tdc gid tdi thieu > 0',15m/s) + Luu lugng gid theo ye'u td khf thai cua cae thie't bi Lugng khdng khf sach can thiet duge tfnh theo edng thCfc: Q,b = k.q.N, m3/phCit (4) • Trong dd: k - He sd tfnh de'n thdi gian hoat ddng va chat tai khdng ddng deu; q - La lugng gid sach can thiet cho IkW cdng sua't may Diezen; q = 6,5m3/phut N - Cdng sua't thiet bi silf dung dau Diezen Can cCf vao ke't qua tinh toan luu lugng gid cho gygng ham theo cac yeu td tren De dam bao duge yeu cau ve an toan va dieu kien vi khf hau ham ngam, ta chgn iLfu lugng gid theo ye'u td Idn nha't lam |yu lugng gid can thie't de thie't ke dUa de'n gygng ham.3.2 Chgn thie't bj + Chon ong gid Khi chgn dng thd'ng gid thudng xem xet tdi cac van de ni sau: Dydng kinh dng gid dam bao chieu dai thdng gid Idn nha't, trudng hgp dien tfch dudng Id cho phep nen chgn dydng kfnh dng gid ed dudng kfnh Idn de giam Iyc can, giam rd gid, tiet kiem tieu phi nang lugng Thdng thydng chieu dai nhd hgn 200m thi chgn dudng kinh dng gid 406mm, chieu dai thdng gid tCf 200m de'n 500m nen chgn dydng kinh dng gid la 500mm + Chon quat gio Viec chgn quat gid can dya vao lugng gid tfnh toan va ap Iyc gid can cung cap de chgn quat Khdng su" dung cac quat cd hieu sua't tha'p de thdng gid va nen sCf dung eae loai quat mdi cd tieng dn tha'p, tiet kiem nang lugng + Khi thi cdng cac dudng ham cd chieu dai Idn can phai xac dinh dugc kha nang td'i da cCia mdt quat gid cd the dam bao dugc luu lugng gid theo yeu eau tdi gugng ham + Luu lugng gid quat tao cd kha nang day dygc cae loai khf ddc, khf nd va bui khdi gygng 16 mdt each nhanh nhat, dam bao lugng dxy gygng ham theo dung quy djnh, nhiet Id ludn nhd hgn 26 ^C va td'e gid dudng Id nam gidi han cho phep bdi Quy pham an toan d cac md tdn tai cac loai quat vdi sd 66 khf ddng hoc cu nhy Prokhodka - 500 2m, SVM - 5m, SVM - 6M va mdi hdn nhy seri VME - 5, VME - CHLB Nga san xua't Khoang hdn chuc nam trd Iai day, eac md da trang bj them nhieu loai quat cua Trung Qud'c nhu YBT - 52-2, YBT - 62 - 2, YBT - 11, 22, 30, DKJ(a) vdi cdng sua't khac Dac biet, thdi gian gan day cac md dasCf dung eae loai quat da cap nhu 2BKJ - N°.'6,3/3bx2, DBKJ N°.7,5/55x5 va sero FBD ed sd ddng hgc hien dai, phuc vu td't cho cdng tac thdng gid dao dudng Id ed chieu dai Idn Bang 1- Cac loai quat th6ng gi6 va dieu kien surdung FB - No.4 FBD - No.4 Lull lifdng gid can cung cap (m^/min) 120 120 Difdng kfnh dng gid (mm) 400 400 Chieu dai difdng id (m) 2000 FB-No.10 FBD-No.lO KHCNM SO 8/2010* CNKT HAM LO Thong tin khoa hoc cong nghe m o 3.3 Cong tac thi cong lap dat quat gid + Lap dat quat gio Quat 6Udc lap dat tai nhung ngi cd khdng khf sach thudng each cac cCfa Id khdng nhd hgn 10m de tranh hut lai gid ban va each mat dat khdng tha'p hgn 0,3m, cung khdng nen dat quat qua xa cLfa ham vi ne'u dat qua xa se d i n de'n chieu dai dng gid tang lam tang tdn that lUu lugng gid tren dydng dng d i n Trong trudng hgp dudng Id ed chieu dai Idn, mdt quat khdng dap Cfng dugc luu lygng gid va ap thi trUdng hgp chung ta phai suf dung hai quat mac ndi tie'p (hinh 2), theo ly thuyet mac ndi tie'p hai quat ed the mac theo eae each sau, (hinh 3.a) hai quat mac ndi tiep tap trung, (hinh 3.b) hai quat mac each mdt doan TCf hai kieu mac quat tren chung ta cd the tha'y duge bieu 66 phan bd ap Iyc cua hai each mac va cung mdt dieu kien ap Iyc nha't djnh Hai quat ndi tie'p lien ap lUc Idn hgn trudng hgp mac ndi tie'p each mdt doan, rd gid cung Idn hdn De tranh dygc ap Iyc cao anh hudng de'n sy pha hoai eua dng gid, anh hudng de'n an toan thdng gid nen ap dung phygng phap ndi quat each mdt doan nha't djnh nao dd nhung ne'u quat thCf hai chgn vj tri lap dat khdng phu hgp (ne'u lap dat qua xa) se dan de'n phu ap doan se gay hien tugng cae khf ban se bj hut vao gay hien tygng tuan hoan gid ban (hinh 3.c), theo kinh nghiem thi hai quat khdng nen lap dat each khoang 1/3 chieu dai toan bd cua dng gid (hinh 3.d) + Lip dat dirdng ong gio - Khi ndi cac dng gid vdi phai dam bao kfn khdng dugc hd gay rd gid Viec treo dudng dng phai treo bang cae mdc treo, dng gid phai dugc treo len hdng dUdng Id hoac ndc Id, dng gid treo phai thang khdng dugc vdng - Khdng dygc sCf dung hai loai dudng dng khae de ndi dng gid, tranh hien tugng ndi khdng kfn lam rd gid - SCf dung dudng dng gid dai de giam md'i ndi, dng gid thydng sCf dung cd chieu dai la 30, 50, 100m (khu vyc gan gUdng sCf dung dng gid tam de ndi dng gid de cho khoang each tCf dau dng gid de'n gUdng dygc dam bao) - Dam bao dau dng gid each gygng khdng Idn hgn 8m, iLfu lugng gid d dau dng gid khdng nhd hon 40m^/phut 3.4 Phun nifdc dap bifi tru'dc quat i.» Hinh Bieu ddphan bdap luc cua quat gid c6 cac hoc dat quat ES^E: ^n ]TTT>>, (a) 3SC nrrT-T^rrrTY-i tii* (b) pgr iTrr>r^ pTTv (c) rrrrTTnTrrp^ (d) Hinh Bleu dd phan bdap luc cua quat th6ng gio cue bg a) Phwang phap noi tiep quat dat tap trung; b) Phuang phap noi tiep quat each mot doan; c) Phuang phap noi tiep quat each mgt doan (tao phu ap); d) Noi tiep quat (vi tri ap luc duang) KHCNM S6 8/2010* CNKT HAM LO Thong tin khoa hoc cong nghe mo Tai vi tri cCfa Id qua trinh thi cdng cac phydng tien van chuyen da't da nguyen vat lieu phuc vu thi cdng da lam che khdng tai cij'a Id rat bui Do quat dat tai khu vyc each CLfa ham 10m nen khd tranh khdi hut cac ban vao thdng gid cho dudng ham 3.5 Quan ly lap dat va van hanh - Theo ddi van hanh quat dam bao an toan van hanh, khdng dygc tien tat md quat - Mdt may quat chi sCf dung cho mdt gygng, khdng dygc khf CH4 khdng dugc vugt qua 1%, khf CO2 khdng dUdc vygt qua 1,5%, - Sau mdi ca lam viec can bd ky thuat, trydng ca phai di kiem tra nang sua't ciia quat gid, lull lydng gid d gydng ham, dydng dng gid, va hien tygng rd gid de cd bien phap khac phue kjp thdi Ket luan - Nhy vay, viec lya chgn phygng phap cue bd thi edng nhung dydng Id ddc dao phai phu hgp vdi quy pham Tuy nhien cung can phai phan tfch, danh gia mdt sd yeu td Tai lieu tham khao Bd Cdng nghiep (2000), Quy pham an toan khai thac than ham Id va diep thach, Ha Ndi „ Tran Xuan Ha, Le Van Thao (1999), Cg sd thie't ke thdng gid md Bai giang dung cho Idp cao hgc khai thac md, Ha Ndi Tran Xuan Ha, Nguyin Van Sung (2003), Bao cao de tai Lap bien phap nang cao hieu qua thdng gid cho cdng ty than Mdng Dygng, Ha Ndi Dinh Hung, Ta Ngge Ha, Vu Cao Dam (1972), thdng gid md, tap 1, tap Dai hoe md - Dja chat, Ha Ndi Dang Vu Chf, Ve van de khoang each giCfa cac quat ndi tie'p de thdng gid dao cae dudng Id Tap chi Cdng nghiep md, sd 3/2009 - »^?-i .'* (^ :y^ phan nhanh cung cap cho gygng khae - Mdt gygng cdng tac khdng dygc sCf dung ba quat trd len - Khi ngCfng thdng gid phai ed bien bao, va cat dien cung cap tai gugng - Trudc thdng gid lai phai kiem tra ndng cac khf nd d vj trf dat quat, ndng edng tae tfnh toan, lya chgn quat gid, dng gid Dae biet la cdng tac lap dat kiem tra phai thudng xuyen ke't hdp vdi dieu kien thuc te cdng trinh nh^m giam chi' phf, nang cae hieu qua cdng tac thdng gid - Khi chieu dai dudng Id Idn, ed the lya chgn chung loai, sd lugng quat va khoang each hgp 1^ cac quat lam viec ndi tiep vdi KHCNM SO 8/2010* CNKT HAM LO Thai Hdng Phygng va nne (2005), Danh gia thdng gid, lap ke hoach va giai phap thdng gid phuc vu cho ke hoach khai thac tCf nam 2005 2010, Xi nghiep than Nam M l u , Ha Ndi G.A.BABAL(1982), Cac thiet bi thdng gid chfnh (tieng Nga) NXB Moskva Keenofontova (1962), So tay thdng gid (tieng Nga) NXB Moskva YmaKOBa K.3 M flpa AapoJiornfl nopHbix npeAnpuflTni'i ynedHi/iKOB fljiyi BysoB M Heflpa 1987, 421c ... gid khdng dung vdi thie''t ke - Do vdng cCia dng gid cdn Idn hon quy djnh cho phep - Khi dao nhu''ng dudng ham cd dia chat khdng dn dinh he sd lem Idn thi cang va thing can thie''t cCia dng gid... cdng nhan thie''u y thCfe lao ddng tim each lam rach dng gid dgc dudng Id - Qua trinh van hanh may mdc, thie''t bj xuc bdc, van chuyen da''t da khdi gygng ham cdng nhan thieu quan sat de thie''t bj... (3) Trong dd: S: Tie''t dien dUdng ham can thdng gid Vcp: Van tdc gid nhd nha''t eho phep (trong quy pham quy dinh van tdc gid tdi thieu > 0'',15m/s) + Luu lugng gid theo ye''u td khf thai cua cae thie''t